Control method, control device, refrigeration cycle device, and program

Abstract

Provided are a control method, a control device, a refrigeration cycle device, and a program, with which it is possible to improve the accuracy of detection of a disproportionation reaction of a working medium, and to improve suppression of the disproportionation reaction. The control method is for a refrigeration cycle circuit in which a working medium 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, wherein the operation of the refrigeration cycle circuit is stopped or restricted if a pre-indication of a disproportionation reaction is detected on the basis of at least one of a first state relating to a drive circuit 31 for driving a compressor 4 of the refrigeration cycle circuit, or a second state relating to the working medium 20.

Description

Control method, control device, refrigeration cycle device, and program

[0001] The present disclosure relates to a control method, a control device, a refrigeration cycle device, and a program.

[0002] Conventionally, R410A has been widely used as a working fluid (heat medium, refrigerant) for refrigeration cycle devices. However, R410A has a high global warming potential (GWP) of 2090. Therefore, from the perspective of preventing global warming, research and development has been conducted on working fluids with lower GWP. Patent Document 1 discloses 1,1,2-trifluoroethylene (HFO1123) as a working fluid with a lower GWP than R410A. Patent Document 2 discloses 1,2-difluoroethylene (HFO1132) as a working fluid with a lower GWP than R410A.

[0003] HFO1123 and HFO1132 have a smaller GWP than R410A, but this makes them less stable than R410A. For example, the generation of radicals can cause disproportionation reactions of HFO1123 or HFO1132, which can change HFO1123 and HFO1132 into other compounds.

[0004] Patent Document 3 states that "the disproportionation reaction begins when high energy is added to the refrigerant in an atmosphere where the refrigerant is excessively high in temperature and pressure (particularly in a compressor), or when excessive collisions between refrigerant molecules and electrons occur due to discharge caused by a layer short or the like."

[0005] Patent Document 3 states, "The present disclosure prevents high energy from being added to the refrigerant in the compressor, or prevents excessive collisions between refrigerant molecules and electrons in the discharge space, thereby suppressing the occurrence of disproportionation reactions. This provides a highly reliable refrigeration cycle device that uses a working fluid containing an ethylenic fluorohydrocarbon having a double bond."

[0006] The refrigeration cycle device described in Patent Document 3 detects a discharge space where the current value of the input current to the compressor motor exceeds a first predetermined value that is set to be three times or more the maximum current value during normal operation other than when the compressor is started, where the current value of the input current to the compressor motor exceeds a second predetermined value that is set to be two times or more the current value during when the compressor is started, and where the number of discharge electrons in the discharge space calculated based on the amount of change in the current value of the input current to the compressor motor exceeds 1.0 x 10 １９ The compressor has a protective device that at least one of cutting off the power supply to the compressor and reducing the rotation speed of the compressor when the number of particles per second exceeds a third predetermined value set at or above a third predetermined value.

[0007] International Publication No. 2012 / 157764 International Publication No. 2012 / 157765 International Publication No. 2019 / 172008

[0008] The refrigeration cycle device disclosed in Patent Document 1 detects signs of a disproportionation reaction using the current value of the input current to the compressor's motor, and suppresses the disproportionation reaction by using a protective device to stop the power supply to the compressor or by reducing the compressor rotation speed.

[0009] The present disclosure provides a control method, a control device, a refrigeration cycle device, and a program that can improve the accuracy of detection of a disproportionation reaction of a working fluid and enable improved suppression of the disproportionation reaction.

[0010] A control method according to one aspect of the present disclosure is a control method for a refrigeration cycle circuit in which a working medium containing a refrigerant component in which a disproportionation reaction may occur circulates, and when a sign of a disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit or a second state related to the working medium, the control method stops or restricts operation of the refrigeration cycle circuit.

[0011] A control device according to one aspect of the present disclosure is a control device that controls a refrigeration cycle circuit in which a working medium containing a refrigerant component in which a disproportionation reaction may occur circulates, and when it detects a sign of a disproportionation reaction based on a drive circuit that drives a compressor of the refrigeration cycle circuit and at least one of a first state related to the drive circuit that drives the compressor of the refrigeration cycle circuit and a second state related to the working medium, it stops or restricts operation of the refrigeration cycle circuit.

[0012] A refrigeration cycle device according to an aspect of the present disclosure includes the above-described control device and the above-described refrigeration cycle circuit.

[0013] A program according to one aspect of the present disclosure is a program executed by a computer system provided in a control device that controls a refrigeration cycle circuit in which a working medium containing a refrigerant component in which a disproportionation reaction may occur circulates, and causes the computer system to execute a process to stop or restrict operation of the refrigeration cycle circuit when it detects a sign of a disproportionation reaction based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit or a second state related to the working medium.

[0014] Aspects of the present disclosure can improve the accuracy of detection of disproportionation reactions of working fluids and enable improved suppression of disproportionation reactions.

[0015]

[0016] [1. Embodiments] Hereinafter, embodiments of the present disclosure will be described, with reference to the drawings where appropriate. However, the following embodiments are merely examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following content (e.g., the shape, dimensions, and arrangement of each component). Positional relationships, such as up, down, left, and right, are based on the positional relationships shown in the drawings unless otherwise specified. Each figure described in the following embodiments is a schematic diagram, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. Furthermore, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0017] In the following description, when it is necessary to distinguish between multiple components, prefixes such as "first" and "second" are added to the names of the components. However, when the components can be distinguished from each other by the symbols attached to them, the prefixes such as "first" and "second" may be omitted in consideration of readability of the text.

[0018] In the following description, when it is necessary to distinguish between multiple components, suffixes such as "-1" and "-2" are added to the symbols of the components. However, when it is not necessary to distinguish between multiple components, the suffixes "-1" and "-2" may be omitted to improve readability.

[0019] 1 is a block diagram of a refrigeration cycle apparatus 1 according to this embodiment. The refrigeration cycle apparatus 1 constitutes, for example, an air conditioner capable of cooling and heating operations. The refrigeration cycle apparatus 1 includes a refrigeration cycle circuit 2 and a control device 3.

[0020] The refrigeration cycle circuit 2 constitutes a flow path through which a working medium 20 (see FIG. 2) circulates. In this embodiment, the working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The ethylene-based fluoroolefin may be an ethylene-based fluoroolefin that undergoes a disproportionation reaction. Examples of ethylene-based fluoroolefins that undergo a disproportionation reaction include 1,1,2-trifluoroethylene (HFO1123), trans-1,2-difluoroethylene (HFO1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), tetrafluoroethylene (CF ２ =CF ２ , FO1114), and monofluoroethylene (HFO-1141). That is, the working medium 20 contains refrigerant components in which a disproportionation reaction can occur.

[0021] The working fluid 20 may contain multiple types of refrigerant components. The working fluid 20 may contain an ethylene-based fluoroolefin as a main refrigerant component and a compound other than an ethylene-based fluoroolefin as a secondary refrigerant component. Examples of the secondary refrigerant component include hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), saturated hydrocarbons, carbon dioxide, etc. Examples of hydrofluorocarbons (HFCs) include difluoromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluorobutane, heptafluorocyclopentane, etc. Examples of hydrofluoroolefins (HFOs) include monofluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, hexafluorobutene, etc. Examples of saturated hydrocarbons include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), methylcyclobutane, and the like.

[0022] The working fluid 20 may further contain a disproportionation inhibitor that suppresses the disproportionation reaction of the ethylene-based fluoroolefin. Examples of disproportionation inhibitors include saturated hydrocarbons or haloalkanes. Examples of saturated hydrocarbons include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), methylcyclobutane, and the like. Of the above examples, n-propane is preferred. Examples of haloalkanes include haloalkanes having one or two carbon atoms. Examples of haloalkanes having one carbon atom (i.e., halomethanes) include (mono)iodomethane (CH ３ I), diiodomethane (CH ２ I ２ ), dibromomethane (CH ２ Br ２ ), bromomethane (CH ３ Br), dichloromethane (CH ２ Cl ２ ), chloroiodomethane (CH ２ ClI), dibromochloromethane (CHBr ２ Cl), tetraiodomethane (Cl ４ ), carbon tetrabromide (CBr ４ ), bromotrichloromethane (CBrCl ３ ), dibromodichloromethane (CBr ２ Cl ２ ), tribromofluoromethane (CBr ３ F), fluorodiiodomethane (CHFI ２ ), difluorodiiodomethane (CF ２ I ２ ), dibromodifluoromethane (CBr ２ F ２ ), trifluoroiodomethane (CF ３ Examples of haloalkanes having two carbon atoms (i.e., haloethanes) include 1,1,1-trifluoro-2-iodoethane (CF ３ CH ２ I), monoiodoethane (CH ３ CH ２I), monobromoethane (CH ３ CH ２ Br), 1,1,1-triiodoethane (CH ３ CI ３ The working fluid 20 may contain one or more types of haloalkanes having 1 or 2 carbon atoms. That is, only one type of haloalkane having 1 or 2 carbon atoms may be used, or two or more types may be used in appropriate combination.

[0023] Here, an experiment was conducted to verify the occurrence of a disproportionation reaction using a working fluid containing 1,1,2-trifluoroethylene (HFO1123). In the disproportionation reaction experiment, a sealed pressure-resistant vessel (stainless steel sealed vessel, internal volume 50 mL) was equipped with a pressure sensor (GC61 manufactured by Nagano Keiki Co., Ltd.) to measure the internal pressure within the pressure-resistant vessel, a thermocouple (PL Thermocouple Grand PL-18-K-A 4-T manufactured by Conax Technologies) to measure the internal temperature within the pressure-resistant vessel, and a discharge device to generate a discharge within the pressure-resistant vessel. Furthermore, a gas cylinder of 1,1,2-trifluoroethylene was connected so that the pressure could be adjusted. A mantle heater was installed to heat the entire pressure-resistant vessel, and a ribbon heater (flexible ribbon heater, 1 m, 200 W manufactured by Tokyo Institute of Technology Co., Ltd.) was also installed to heat the piping. This constituted an experimental system for the disproportionation reaction.

[0024] Table 1 below shows whether or not a disproportionation reaction occurred when the working fluid was 1,1,2-trifluoroethylene alone (Examples 1 and 2), a mixed gas adjusted to have a 1,1,2-trifluoroethylene content of 80 mass% and an n-propane content of 20 mass% (Example 3), a mixed gas adjusted to have a 1,1,2-trifluoroethylene content of 91.5 mass%, an n-propane content of 7.5 mass%, and a difluoroiodomethane content of 1.0 mass% (Example 4), and a mixed gas adjusted to have a 1,1,2-trifluoroethylene content of 69.5 mass%, an difluoromethane content of 22 mass%, an n-propane content of 7.5 mass%, and a difluoroiodomethane content of 1.0 mass% (Example 5). The pressure was adjusted to 2 MPa in Examples 1 and 2, and 6 MPa in Examples 3 to 5. The stored energy in Table 1 is electrostatic energy stored in a capacitor unit installed inside the discharge device. The number of discharges is the number of times discharged at regular intervals under the conditions in question. If a disproportionation reaction was observed after that number of discharges, the presence or absence of a disproportionation reaction was recorded as "Yes," and if no disproportionation reaction was observed, the presence or absence was recorded as "No."

[0025]

[0026] From Table 1, no disproportionation reaction was observed in Example 1. Therefore, it was confirmed that there is an extremely low possibility of a disproportionation reaction occurring in a slight discharge in which the stored energy is less than 0.5 J. Furthermore, from Table 1, a disproportionation reaction was observed in Example 2. Therefore, it was confirmed that there is a high possibility of a disproportionation reaction occurring after two consecutive discharges when the stored energy is large. Table 1 shows that the greater the stored energy, i.e., the more energy is consumed in discharging, the higher the possibility of a disproportionation reaction occurring. This shows that in order to suppress a disproportionation reaction, it is preferable to keep the discharge state at a slight level, i.e., to detect the disproportionation reaction early and suppress the disproportionation reaction.

[0027] As can be seen from Table 1, in Example 3, no disproportionation reaction was observed in the working fluid of a mixed gas containing n-propane as a disproportionation inhibitor. Example 3 uses a larger amount of stored energy than Example 2, in which disproportionation was observed in 1,1,2-trifluoroethylene alone. Therefore, it was confirmed that in a working fluid containing n-propane as a disproportionation inhibitor, that is, even when the stored energy is increased by the disproportionation inhibitor, the possibility of a disproportionation reaction occurring in a small, minor discharge is extremely low. This indicates that, in order to suppress a disproportionation reaction in a working fluid of a mixed gas containing a disproportionation inhibitor, it is preferable to limit the discharge to a minor state, that is, to detect the disproportionation reaction early and suppress it.

[0028] As can be seen from Table 1, in Example 4, no disproportionation reaction was observed in the working fluid of a mixed gas containing n-propane and difluoroiodomethane as disproportionation inhibitors. Example 4 uses a larger stored energy than Example 2, in which disproportionation was observed in 1,1,2-trifluoroethylene alone. Therefore, it was confirmed that even in a working fluid containing difluoroiodomethane as a disproportionation inhibitor other than n-propane, i.e., in cases where the stored energy is increased by two or more disproportionation inhibitors, the possibility of a disproportionation reaction occurring in a small, minor discharge is extremely low. This indicates that, in order to suppress a disproportionation reaction in a working fluid of a mixed gas containing two or more disproportionation inhibitors, it is preferable to limit the discharge to a minor state, i.e., to detect the disproportionation reaction early and suppress it.

[0029] As can be seen from Table 1, in Example 5, no disproportionation reaction was observed in a working fluid of a mixed gas containing difluoromethane as a disproportionation inhibitor other than n-propane and difluoroiodomethane as a secondary refrigerant component. Example 5 uses a larger amount of stored energy than Example 2, in which disproportionation was observed in 1,1,2-trifluoroethylene alone. Therefore, it was confirmed that even in a working fluid containing a secondary refrigerant component that does not cause disproportionation, where the stored energy is increased by two or more disproportionation inhibitors, the possibility of disproportionation reaction occurring in a small, minor discharge is extremely low. This indicates that in order to suppress disproportionation reactions in a working fluid of a mixed gas containing two or more disproportionation inhibitors and one or more secondary refrigerants, it is preferable to limit the discharge to a minor state, i.e., to detect the disproportionation reaction early and suppress it.

[0030] As a result of extensive investigation into the mechanism of the disproportionation reaction, the inventors have found that the decomposition of ethylene-based fluoroolefins proceeds along a nearly common reaction pathway, that the radical species produced are the same with only their composition changing, and that the thermal decomposition temperatures are nearly the same. In other words, even with ethylene-based fluoroolefins other than 1,1,2-trifluoroethylene, the generation of a small amount of radicals by a slight discharge and this occurring intermittently multiple times does not result in a disproportionation reaction, but rather that the disproportionation reaction proceeds only when a large amount of radicals is produced by a high-energy discharge.

[0031] The refrigeration cycle circuit 2 includes a compressor 4 , a first heat exchanger 5 , an expansion valve 6 , a second heat exchanger 7 , and a four-way valve 8 .

[0032] The refrigeration cycle apparatus 1 includes an outdoor unit 1a and an indoor unit 1b. The outdoor unit 1a includes a control device 3, a compressor 4, a first heat exchanger 5, an expansion valve 6, and a four-way valve 8. The outdoor unit 1a further includes a first blower 5a for promoting heat exchange in the first heat exchanger 5. The indoor unit 1b includes a second heat exchanger 7. The indoor unit 1b further includes a second blower 7a for promoting heat exchange in the second heat exchanger 7.

[0033] In the refrigeration cycle circuit 2, the compressor 4 compresses the working medium to increase its pressure. The compressor 4 will be described in detail later. The first heat exchanger 5 and the second heat exchanger 7 exchange heat between the working medium circulating through the refrigeration cycle circuit 2 and external air (e.g., outside air or room air). The expansion valve 6 adjusts the pressure (evaporation pressure) of the working medium and the flow rate of the working medium. The four-way valve 8 switches the direction of the working medium circulating through the refrigeration cycle circuit 2 between a first direction corresponding to cooling operation and a second direction corresponding to heating operation.

[0034] In this embodiment, the first direction is the direction in which the working medium circulates through the refrigeration cycle circuit 2, in the order of the compressor 4, the first heat exchanger 5, the expansion valve 6, and the second heat exchanger 7, as indicated by the solid arrow A1 in FIG. 1 .

[0035] During cooling operation, the compressor 4 compresses and discharges the gaseous working medium, which is then sent to the first heat exchanger 5 via the four-way valve 8. The first heat exchanger 5 exchanges heat between the outside air and the gaseous working medium, causing the gaseous working medium to condense and liquefy. The liquid working medium is decompressed by the expansion valve 6 and sent to the second heat exchanger 7. The second heat exchanger 7 exchanges heat between the liquid working medium and the indoor air, causing the liquid working medium to evaporate and become a gaseous working medium. The gaseous working medium returns to the compressor 4 via the four-way valve 8. During cooling operation, the first heat exchanger 5 functions as a condenser, and the second heat exchanger 7 functions as an evaporator. Therefore, during cooling, the indoor unit 1b blows air cooled by heat exchange in the second heat exchanger 7 into the room.

[0036] In this embodiment, the second direction is the direction in which the working medium circulates through the refrigeration cycle circuit 2, in the order of the compressor 4, the second heat exchanger 7, the expansion valve 6, and the first heat exchanger 5, as indicated by the dashed arrow A2 in FIG.

[0037] During heating operation, the compressor 4 compresses and discharges the gaseous working medium, which is then sent to the second heat exchanger 7 via the four-way valve 8. The second heat exchanger 7 exchanges heat between the room air and the gaseous working medium, causing the gaseous working medium to condense and liquefy. The liquid working medium is decompressed by the expansion valve 6 and sent to the first heat exchanger 5. The first heat exchanger 5 exchanges heat between the liquid working medium and outside air, causing the gaseous working medium to evaporate and become a gaseous working medium. The gaseous working medium returns to the compressor 4 via the four-way valve 8. During heating operation, the first heat exchanger 5 functions as an evaporator, and the second heat exchanger 7 functions as a condenser. Therefore, during heating, the indoor unit 1b blows air heated by heat exchange in the second heat exchanger 7 into the room.

[0038] The control device 3 controls the compressor 4 of the refrigeration cycle circuit 2. FIG.

[0039] The compressor 4 is, for example, a hermetic compressor. The compressor 4 may be a rotary type, a scroll type, or any other known type. The compressor 4 includes a hermetic container 40, a compression mechanism 41, and an electric motor 42.

[0040] The sealed container 40 forms a flow path for the working medium 20. The sealed container 40 has a suction pipe 401 and a discharge pipe 402. The working medium 20 is sucked into the sealed container 40 from the suction pipe 401, compressed by the compression mechanism 41, and then discharged from the discharge pipe 402 to the outside of the sealed container 40. The inside of the sealed container 40 is filled with the high-temperature and high-pressure working medium 20 and lubricating oil. The bottom of the sealed container 40 forms an oil reservoir that stores a mixture of the working medium 20 and lubricating oil.

[0041] The compression mechanism 41 is located inside the sealed container 40 and compresses the working medium. The compression mechanism 41 may have a conventionally known configuration. The compression mechanism 41 has, for example, a cylinder that forms a compression chamber, a rolling piston that is disposed in the compression chamber inside the cylinder, and a crankshaft that is coupled to the rolling piston.

[0042] The electric motor 42 is located inside the sealed container 40 and drives the compression mechanism 41. The electric motor 42 is, for example, a brushless motor (three-phase brushless motor). The electric motor 42 includes, for example, a rotor fixed to the crankshaft of the compression mechanism 41 and a stator disposed around the rotor. The stator is configured, for example, by concentrating or dispersing a stator winding (magnet wire, etc.) around a stator core (electromagnetic steel plate, etc.) with an insulating material such as insulating paper interposed therebetween. The stator winding is covered with an insulating material. Examples of insulating materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), aramid polymer, polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), etc.

[0043] The compressor 4 may include an accumulator to prevent liquid compression in the compression chamber of the compression mechanism 41. The accumulator separates the working medium into a gaseous working medium and a liquid working medium, and introduces only the gaseous working medium from the suction pipe 401 into the inside of the sealed container 40.

[0044] The control device 3 includes a drive circuit 31 and a control circuit 35 .

[0045] The drive circuit 31 drives the electric motor 42 based on input power from the power supply 10. In this embodiment, the power supply 10 is an AC power supply, and the input power is AC power. The drive circuit 31 includes a converter circuit 311 and an inverter circuit 312.

[0046] The converter circuit 311 outputs DC output power based on the input power from the power supply 10 so that the voltage becomes a first voltage. That is, the converter circuit 311 converts the input power into DC output power so that the voltage of the DC output power becomes the first voltage. The first voltage corresponds to the rated voltage of the drive circuit 31.

[0047] The converter circuit 311 includes a rectifier circuit 311a and a smoothing circuit 311b.

[0048] The rectifier circuit 311a is a diode bridge composed of a plurality of diodes D1 to D4. The power supply 10 is connected between the input terminals of the rectifier circuit 311a (the connection point between the diodes D1 and D2 and the connection point between the diodes D3 and D4), and the smoothing circuit 311b is connected between the output terminals of the rectifier circuit 311a (the connection point between the diodes D1 and D3 and the connection point between the diodes D2 and D4).

[0049] The smoothing circuit 311b smoothes and outputs the voltage between the output terminals of the rectifier circuit 311a. The smoothing circuit 311b sets the voltage of the DC output power to a first voltage. The smoothing circuit 311b includes a series circuit of an inductor L1 and smoothing capacitors C1 and C2. In the smoothing circuit 311b, the connection point between the inductor L1 and the smoothing capacitor C1 is a first output point P1 that outputs a voltage corresponding to the first voltage. In the smoothing circuit 311b, the connection point between the diodes D2 and D4 and the smoothing capacitor C2 is a second output point P2 that outputs a voltage lower than the voltage at the first output point P1. In the smoothing circuit 311b, the connection point between the smoothing capacitor C1 and the smoothing capacitor C2 is a third output point P3 that outputs a voltage between the voltage at the first output point P1 and the voltage at the second output point P2. In the relationship between the first output point P1, the second output point P2, and the third output point P3, the first output point P1 is a high-voltage point, the second output point P2 is a low-voltage point, and the third output point P3 is an intermediate-voltage point. In the smoothing circuit 311b, the smoothing capacitors C1 and C2 have the same capacitance. Therefore, the voltage between the first output point P1 and the third output point P3 is equal to the voltage between the second output point P2 and the third output point P3. If the voltage between the first output point P1 and the second output point P2 (which corresponds to the first voltage) is E, the voltage between the first output point P1 and the third output point P3 is E / 2, and similarly, the voltage between the second output point P2 and the third output point P3 is E / 2. This allows the drive circuit 31 to provide five voltage levels: E, E / 2, 0, −E / 2, and −E.

[0050] The inverter circuit 312 outputs AC output power to the electric motor 42 based on the DC output power from the converter circuit 311. In the present embodiment, the AC output power is three-phase AC power. The inverter circuit 312 includes a plurality of semiconductor switching elements U1 to U4, V1 to V4, and W1 to W4. The semiconductor switching elements U1 to U4, V1 to V4, and W1 to W4 are, for example, transistors.

[0051] The semiconductor switching elements U1 to U4, V1 to V4, and W1 to W4 each form a series circuit and are connected between a first output point P1 and a second output point P2.

[0052] The connection point of the semiconductor switching elements U1 and U2, the connection point of the semiconductor switching elements V1 and V2, and the connection point of the semiconductor switching elements W1 and W2 are connected to a third output point P3 via diodes D5, D7, and D9, respectively.

[0053] The anodes of diodes D5, D7, and D9 are connected to the third output point P3, and the cathodes of diodes D5, D7, and D9 are connected to the connection point of semiconductor switching elements U1 and U2, the connection point of semiconductor switching elements V1 and V2, and the connection point of semiconductor switching elements W1 and W2, respectively.

[0054] The connection point of the semiconductor switching elements U2 and U3 forms a U-phase output terminal Pu connected to a U-phase input terminal of the motor 42. The connection point of the semiconductor switching elements V2 and V3 forms a V-phase output terminal Pv connected to a V-phase input terminal of the motor 42. The connection point of the semiconductor switching elements W2 and W3 forms a W-phase output terminal Pw connected to a W-phase input terminal of the motor 42.

[0055] The connection point of the semiconductor switching elements U3 and U4, the connection point of the semiconductor switching elements V3 and V4, and the connection point of the semiconductor switching elements W3 and W4 are connected to a third output point P3 via diodes D6, D8, and D10, respectively.

[0056] The cathodes of diodes D6, D8, and D10 are connected to the third output point P3, and the anodes of diodes D6, D8, and D10 are connected to the connection point of semiconductor switching elements U3 and U4, the connection point of semiconductor switching elements V3 and V4, and the connection point of semiconductor switching elements W3 and W4, respectively.

[0057] In the inverter circuit 312, the semiconductor switching elements U1, U2, V1, V2, W1, and W2 constitute a first semiconductor switching element group connected between the first output point P1 and the electric motor 42. In particular, the semiconductor switching elements U1 and U2 constitute a U-phase first semiconductor switching element group connected between the first output point P1 and the U-phase input terminal of the electric motor 42. The semiconductor switching elements V1 and V2 constitute a V-phase first semiconductor switching element group connected between the first output point P1 and the V-phase input terminal of the electric motor 42. The semiconductor switching elements W1 and W2 constitute a W-phase first semiconductor switching element group connected between the first output point P1 and the W-phase input terminal of the electric motor 42.

[0058] The semiconductor switching elements U3, U4, V3, V4, W3, and W4 constitute a second semiconductor switching element group connected between the second output point P2 and the motor 42. In particular, the semiconductor switching elements U3 and U4 constitute a U-phase second semiconductor switching element group connected between the second output point P2 and a U-phase input terminal of the motor 42. The semiconductor switching elements V3 and V4 constitute a V-phase second semiconductor switching element group connected between the second output point P2 and a V-phase input terminal of the motor 42. The semiconductor switching elements W3 and W4 constitute a W-phase second semiconductor switching element group connected between the second output point P2 and a W-phase input terminal of the motor 42.

[0059] The semiconductor switching elements U2, U3, V2, V3, W2, and W3 constitute a third semiconductor switching element group connected between the third output point P3 and the electric motor 42. In particular, the semiconductor switching elements U2 and U3 constitute a U-phase third semiconductor switching element group connected between the third output point P3 and the U-phase input terminal of the electric motor 42. The semiconductor switching elements V2 and V3 constitute a V-phase third semiconductor switching element group connected between the third output point P3 and the V-phase input terminal of the electric motor 42. The semiconductor switching elements W2 and W3 constitute a W-phase third semiconductor switching element group connected between the third output point P3 and the W-phase input terminal of the electric motor 42.

[0060] The converter circuit 311 has a plurality of output points including first to third output points P1 to P3. The inverter circuit 312 has a plurality of semiconductor switching element groups including a first semiconductor switching element group (semiconductor switching elements U1, U2, V1, V2, W1, W2) connected between the first output point P1 and the motor 42, a second semiconductor switching element group (semiconductor switching elements U3, U4, V3, V4, W3, W4) connected between the second output point P2 and the motor 42, and a third semiconductor switching element group (semiconductor switching elements U2, U3, V2, V3, W2, W3) connected between the third output point P3 and the motor 42. The drive circuit 31 is a so-called multilevel inverter, particularly a three-level inverter.

[0061] The voltage detector 32 detects the DC output power of the converter circuit 311 and outputs a detection voltage indicating the voltage of the DC output power. In this embodiment, the voltage detector 32 includes a voltage divider circuit connected between the output terminals of the smoothing circuit 311b of the converter circuit 311, i.e., between the first output point P1 and the second output point P2, and outputs the detection voltage based on the voltage obtained from the voltage divider circuit. Alternatively, the voltage detector 32 may output the detection voltage based on the output of the voltage divider circuit and a differential amplifier. For example, the non-inverting input terminal and the inverting input terminal of the differential amplifier may be connected to both ends of a resistor in the voltage divider circuit, respectively, and the differential amplifier may output the voltage across the resistor as the detection voltage. Using the differential amplifier allows the potential difference in the floating state to be detected, thereby improving the accuracy of the detection voltage. The location where the voltage detector 32 is connected to the drive circuit 31 is not particularly limited, as long as it is located at a position where the DC output power of the converter circuit 311 can be detected. The position at which the DC output power of the converter circuit 311 can be detected is not limited to within the converter circuit 311, but may be a position within the inverter circuit 312 that is equivalent in circuit terms to each of the first output point P1 and the second output point P2. The voltage divider circuit of the voltage detector 32 can employ a conventionally well-known configuration, and therefore a detailed description thereof will be omitted.

[0062] The first protection device 33 is provided to stop the output of AC output power. The first protection device 33 includes switches Su, Sv, and Sw interposed between the drive circuit 31 and the electric motor 42. The switches Su, Sv, and Sw are connected between the U-phase, V-phase, and W-phase input terminals of the electric motor 42 and the U-phase output terminals Pu, Pv, and Pw, respectively. The switches Su, Sv, and Sw may be controllable switches such as semiconductor switches or electromagnetic relays. When the switches Su, Sv, and Sw are closed in an ON state, the first protection device 33 allows the output of AC output power from the drive circuit 31 to the electric motor 42. When the switches Su, Sv, and Sw are open in an OFF state, the first protection device 33 stops the output of AC output power from the drive circuit 31 to the electric motor 42.

[0063] The second protection device 34 is provided to stop the input of input power. The second protection device 34 includes switches S1 and S2 interposed between the drive circuit 31 and the power source 10. The switches S1 and S2 are respectively connected between the input terminal of the rectifier circuit 311a and the power source 10. The switches S1 and S2 may be controllable switches such as semiconductor switches or electromagnetic relays. When the switches S1 and S2 are closed in an on state, the second protection device 34 allows the input of input power from the power source 10 to the drive circuit 31, and when the switches S1 and S2 are open in an off state, the second protection device 34 stops the input of input power from the power source 10 to the drive circuit 31.

[0064] The control circuit 35 may be realized, for example, by a computer system including at least one processor (microprocessor) and one or more memories. The computer system may also include one or more A / D converters. For example, the one or more A / D converters are used to convert the detected voltage from the voltage detector 32 from analog to digital format. The control circuit 35 controls the drive circuit 31, the first protection device 33, and the second protection device 34. In particular, the control circuit 35 performs PWM control of a group of semiconductor switching elements in the inverter circuit 312 of the drive circuit 31 so that the drive circuit 31 operates the electric motor 42. More specifically, the control circuit 35 controls the switching of the semiconductor switching elements U1 to U4, V1 to V4, and W1 to W4 in the inverter circuit 312 of the drive circuit 31 so that the inverter circuit 312 supplies AC output power (three-phase AC power) to the electric motor 42 based on the DC output power from the smoothing circuit 311b.

[0065] The semiconductor switching elements U1 to U4 have three states: a first state in which the semiconductor switching elements U1 and U2 are on and the semiconductor switching elements U3 and U4 are off, a second state in which the semiconductor switching elements U3 and U4 are on and the semiconductor switching elements U1 and U2 are off, and a third state in which the semiconductor switching elements U2 and U3 are on and the semiconductor switching elements U1 and U4 are off. The voltage at the U-phase output terminal Pu is E / 2 in the first state, −E / 2 in the second state, and 0 in the third state.

[0066] The semiconductor switching elements V1 to V4 have three states: a first state in which the semiconductor switching elements V1 and V2 are on and the semiconductor switching elements V3 and V4 are off, a second state in which the semiconductor switching elements V3 and V4 are on and the semiconductor switching elements V1 and V2 are off, and a third state in which the semiconductor switching elements V2 and V3 are on and the semiconductor switching elements V1 and V4 are off. The voltage at the V-phase output terminal Pv is E / 2 in the first state, −E / 2 in the second state, and 0 in the third state.

[0067] The semiconductor switching elements W1 to W4 have three states: a first state in which the semiconductor switching elements W1 and W2 are on and the semiconductor switching elements W3 and W4 are off, a second state in which the semiconductor switching elements W3 and W4 are on and the semiconductor switching elements W1 and W2 are off, and a third state in which the semiconductor switching elements W2 and W3 are on and the semiconductor switching elements W1 and W4 are off. The voltage at the W-phase output terminal Pw is E / 2 in the first state, −E / 2 in the second state, and 0 in the third state.

[0068] In this way, the drive circuit 31 can provide voltages at five levels: E, E / 2, 0, −E / 2, and −E.

[0069] The control circuit 35 controls the switching of the semiconductor switching elements U1 to U4, V1 to V4, and W1 to W4 of the inverter circuit 312 of the drive circuit 31 based on, for example, U-phase, V-phase, and W-phase output voltage command values ​​corresponding to the sinusoidal AC voltages of the U-phase, V-phase, and W-phase of the three-phase AC, respectively, and on the basis of first and second carrier triangular waves. The value of the first carrier triangular wave is equal to or greater than 0, and the value of the second carrier triangular wave is equal to or less than 0. The drive circuit 31 can apply five voltage levels, E, E / 2, 0, −E / 2, and −E, thereby making the voltage between the U-phase input terminal and the V-phase input terminal of the motor 42, the voltage between the V-phase input terminal and the W-phase input terminal of the motor 42, and the voltage between the W-phase input terminal and the U-phase input terminal of the motor 42 each closer to a sine wave.

[0070] The control circuit 35 further executes a process for suppressing the disproportionation reaction of the working medium 20 circulating through the refrigeration cycle circuit 2 based on the detected voltage from the voltage detector 32 .

[0071] It is believed that heat and radicals are factors that cause the disproportionation reaction of the working fluid 20. For example, it is believed that the disproportionation reaction of the working fluid 20 progresses when radicals are generated under high temperature and high pressure. The radicals may be generated by a discharge phenomenon that may occur when some abnormality occurs in the compressor 4 or the drive circuit 31, for example.

[0072] When the disproportionation reaction of the working medium 20 proceeds starting from a discharge phenomenon, the generation of plasma or a reaction fireball is observed in the working medium 20. The disproportionation reaction of the working medium 20 generates products from the working medium 20. The products may include intermediate products or final products. The final products refer to thermodynamically stable chemical species among the chemical species generated in the disproportionation reaction of the working medium 20. Here, "thermodynamically stable" refers to the fact that the type and composition of the compound do not change when exposed to a high temperature of 2000 K or higher at 1 atmosphere for a predetermined time (e.g., approximately 10 minutes) and then returned to room temperature and atmospheric pressure. The intermediate products refer to thermodynamically unstable chemical species among the chemical species generated in the disproportionation reaction of the working medium 20. "Thermodynamically unstable" refers to the fact that at least one of the type and composition of the compound changes when exposed to a high temperature of 2000 K or higher at 1 atmosphere. Thermodynamically unstable chemical species also include so-called metastable chemical species. In particular, the intermediate products are chemical species that may exist with a lifetime of 1 ms or more among the chemical species generated in the disproportionation reaction of the working fluid 20, but may decompose at high temperatures (e.g., 2000 K or higher) to generate final products. Naturally, such intermediate products do not include final products. The lifetime here is measured under a measurement environment corresponding to the interior of the refrigeration cycle circuit 2. As an example, the lifetime is measured under conditions of a maximum temperature of 500 K and a maximum pressure of 6 MPa.

[0073] For example, when the working fluid 20 contains an ethylene-based fluoroolefin as a refrigerant component, the intermediate products include carbenes, carbene inserts (compounds produced by the insertion reaction of carbene), tetrafluoroethylene, perfluoroolefins, and fluorobenzene. The final products include soot, hydrogen fluoride, and tetrafluoromethane.

[0074] Considering the progression of such a disproportionation reaction, it is considered possible to detect a sign of a disproportionation reaction based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 and a second state related to the working fluid 20. The first state is a state of the drive circuit 31 that can be used to determine the occurrence of a discharge phenomenon in the compressor 4. The second state is a state of the working fluid 20 that can be used to determine the light emission of the working fluid 20 due to the generation of plasma or a reaction fireball, or the amount of products generated from the working fluid 20. Note that the sign of a disproportionation reaction here refers to a sign of propagation of a disproportionation reaction throughout the working fluid 20, rather than a sign of a local disproportionation reaction in the working fluid 20. In other words, if local disproportionation reactions occur frequently, there is a risk that the disproportionation reaction will eventually spread throughout the working fluid 20.

[0075] The inventors discovered that when a discharge occurs in the compressor 4, a sudden change occurs in the voltage of the DC output power of the converter circuit 311, i.e., the voltage of the smoothing circuit 311b of the drive circuit 31. FIG. 3 is a waveform diagram of the voltage of the DC output power of the converter circuit 311. In FIG. 3, the voltage of the DC output current gradually decreases from time t11 to t12, t21 to t22, t31 to t32, t41 to t42, and t51 to t52. This voltage decrease is due to the switching of the semiconductor switching elements U1 to U4, V1 to V4, and W1 to W4 of the inverter circuit 312. If the switching frequency of the inverter circuit 312 is, for example, 1.0 kHz to 5.0 kHz, the time between time t11 and time t21 is approximately 0.2 to 1.0 ms. At time t33, a sudden drop in the voltage of the DC output current is observed, which is believed to be due to the occurrence of a discharge phenomenon.

[0076] From this perspective, the control circuit 35 determines whether a discharge phenomenon has occurred based on the detected voltage from the voltage detector 32, and if it determines that a discharge phenomenon has occurred, it stops or restricts the operation of the drive circuit 31 in order to suppress the disproportionation reaction of the working medium circulating through the refrigeration cycle circuit 2.

[0077] The control device 3 detects a sign of a disproportionation reaction based on a change in the DC output power (voltage of the smoothing circuit 311b) inside the drive circuit 31, rather than a change in the current actually flowing from the drive circuit 31 to the electric motor 42. The time scale of the discharge phenomenon is shorter than the time scale of smoothing (rectification) in the drive circuit 31. For example, the time scale of the discharge phenomenon is on the order of μs. Therefore, whether a discharge phenomenon is occurring can be determined based on the DC output power inside the drive circuit 31. Furthermore, measurement of the DC output power (voltage of the smoothing circuit 311b) inside the drive circuit 31 can be performed in a shorter time and at a shorter cycle than measurement of the current actually flowing from the drive circuit 31 to the electric motor 42. This enables earlier detection of a sign of a disproportionation reaction of the working fluid 20. If a sign of a disproportionation reaction of the working fluid 20 can be detected earlier in this way, the disproportionation reaction can be suppressed earlier, thereby improving the suppression of the disproportionation reaction.

[0078] In this embodiment, the control circuit 35 stops or limits the operation of the drive circuit 31 when the detected voltage falls below a second voltage that is equal to or less than the first voltage. The second voltage is set to determine whether a discharge phenomenon has occurred, which can occur when some abnormality occurs in the compressor 4 or the drive circuit 31. Referring to FIG. 3 , if the normal voltage (first voltage) of the DC output current is E, it has been observed that the voltage of the DC output current falls below 0.8E, or even below 0.3E, due to a discharge phenomenon. From this perspective, the second voltage is preferably between 0.3 and 0.8 times the first voltage. In this embodiment, the second voltage is 0.8 times the first voltage.

[0079] In the control device 3 described above, the voltage detector 32 detects the DC output power and outputs a detected voltage indicating the voltage of the DC output power as a first state. When the control circuit 35 detects a sign of a disproportionation reaction based on the first state related to the drive circuit 31, it stops or limits the operation of the refrigeration cycle circuit 2. Here, the control circuit 35 determines the number of times that a discharge phenomenon has occurred in the compressor 4 based on the number of times that the detected voltage has become less than a second voltage that is equal to or less than the first voltage. A sign of a disproportionation reaction is when the number of times that a discharge phenomenon has occurred is equal to or greater than a predetermined number.

[0080] Stopping or limiting the operation of the refrigeration cycle circuit 2 may include stopping the operation of the drive circuit 31, increasing the rotation speed of the condenser fan, decreasing the rotation speed of the evaporator fan, increasing the opening of the expansion valve, (if the refrigeration cycle device 1 has multiple indoor units 1b) opening the expansion valve of at least one of the indoor units 1b that are not operating, and (in the case of heating operation) switching to cooling operation using the four-way valve 8 and opening the expansion valve 6.

[0081] The operation of the drive circuit 31 can be stopped by stopping the output of AC output power, stopping the output of DC output power, or stopping the input of input power. When stopping the output of AC output power, the control circuit 35 sets the first protection device 33 to an OFF state to electrically isolate the motor 42 from the drive circuit 31 and stop the output of AC output power. When resuming the output of AC output power, the control circuit 35 sets the first protection device 33 to an ON state to connect the motor 42 to the drive circuit 31. When stopping the input of input power, the control circuit 35 sets the second protection device 34 to an OFF state to electrically isolate the power source 10 from the drive circuit 31 and stop the output of AC output power. When resuming the input of input power, the control circuit 35 sets the second protection device 34 to an ON state to connect the power source 10 to the drive circuit 31.

[0082] The operation of the drive circuit 31 can be limited by lowering the set value of the amplitude of the AC output power or the set value of the frequency of the AC output power. The control circuit 35 controls the drive circuit 31 to lower the set value of the amplitude of the AC output power. In this embodiment, the drive circuit 31 can apply five levels of voltage: E, E / 2, 0, −E / 2, and −E, so the set value of the amplitude of the AC output power is changed from E to E / 2. In this case, the rotation speed of the motor 42 is lower than when the set value of the amplitude of the AC output power is E.

[0083] When the input of input power is stopped, the output of AC output power is stopped as a result. In this embodiment, the control circuit 35 sets the second protection device 34 to the OFF state to electrically isolate the power supply 10 from the drive circuit 31 and stop the output of AC output power. When the input of input power is resumed, the control circuit 35 sets the second protection device 34 to the ON state to connect the power supply 10 to the drive circuit 31.

[0084] The control circuit 35 stops or limits the operation of the drive circuit 31 in different ways depending on the number of times the detected voltage falls below the second voltage. In particular, the control circuit 35 executes processing to suppress the disproportionation reaction to a higher degree as the number of times the detected voltage falls below the second voltage increases. This enables the control device 3 to suppress the disproportionation reaction even when relatively minor discharge phenomena occur consecutively within a short period of time. For example, this prevents the disproportionation reaction from being induced by consecutive low-energy abnormal states (discharges) exceeding a predetermined energy, thereby improving the safety of use of the working fluid 20.

[0085] The control circuit 35 stops or limits the operation of the drive circuit 31 in different ways depending on the time difference between the first time when the detected voltage first becomes less than the second voltage and the second time when the detected voltage next becomes less than the second voltage. In particular, the control circuit 35 executes processing that suppresses the disproportionation reaction to a greater extent the shorter the time difference. This enables the control device 3 to suppress the disproportionation reaction even when relatively minor discharge phenomena occur consecutively within a short period of time. This prevents, for example, the disproportionation reaction from being induced by consecutive low-energy abnormal states (discharges) exceeding a predetermined energy, thereby improving the safety of use of the working fluid 20.

[0086] The process for suppressing the disproportionation reaction includes, for example, first to third processes. The first process is a process of stopping the output of AC output power and resuming the output of AC output power after a standby time has elapsed. The second process is a process of stopping the output of AC output power and operating with a reduced set value for the amplitude of the AC output power after a standby time has elapsed. The third process is a process of stopping the output of AC output power and stopping the input of input power. Among the first to third processes, the degree of suppression of the disproportionation reaction increases in the order of the third process, the second process, and the first process. In the first or second process, the longer the standby time, the higher the degree of suppression of the disproportionation reaction.

[0087] Next, an example of the operation of the control circuit 35 of the control device 3 will be briefly described with reference to Figures 4 to 9. Each of Figures 4 to 9 is a part of a flowchart of the operation of the control circuit 35 of the control device 3, and Figures 4 to 9 are combined to form a complete flowchart.

[0088] Referring to Figure 4, the control circuit 35 causes the drive circuit 31 to output AC output power to the motor 42 based on the input power of the power supply 10, thereby driving the compressor 4. The control circuit 35 sets the number of abnormalities to 0 (S10). The number of abnormalities indicates the number of times the detected voltage has fallen below the second voltage. The number of abnormalities is an indicator of the likelihood of a disproportionation reaction occurring.

[0089] The control circuit 35 acquires the detected voltage from the voltage detector 32 (S11). The control circuit 35 determines whether the detected voltage is less than the second voltage (S12).

[0090] If the detected voltage is not less than the second voltage (S12: NO), the process returns to step S10. In steps S11 and S12, the control circuit 35 determines whether the detected voltage is less than the second voltage at a predetermined cycle. The predetermined cycle here is preferably shorter than the cycle corresponding to the reference frequency of the inverter circuit 312 (e.g., 1000 to 5000 Hz).

[0091] In step S12, if the detected voltage is less than the second voltage (S12: YES), the control circuit 35 adds 1 to the number of abnormalities (S13), and determines whether the number of abnormalities is 1 or less (S14).

[0092] If the number of abnormalities is 1 or less in step S14 (S14: YES), the control circuit 35 sets the first protection device 33 to the OFF state to stop the output of AC output power (S15). The control circuit 35 determines whether a first standby time has elapsed since the output of AC output power was stopped (S16). The first standby time is, for example, 1 second. When the first standby time has elapsed (S16: YES), the control circuit 35 sets the first protection device 33 to the ON state to resume the output of AC output power (S17), thereby restarting the operation of the compressor 4 (S18). After that, the process returns to step S11.

[0093] In this way, the control circuit 35 stops outputting the AC output power when the detected voltage becomes lower than the second voltage, and resumes outputting the AC output power when the first standby time has elapsed since the output of the AC output power was stopped.

[0094] If the number of abnormalities is not equal to or less than 1 in step S14 (S14: NO), referring to FIG. 5, the control circuit 35 determines whether the time difference between the first time when the detected voltage first fell below the second voltage and the second time when the detected voltage next fell below the second voltage is within a first predetermined time (step S19). A short time difference is an indicator of the likelihood of a disproportionation reaction occurring. The first predetermined time is, for example, approximately 100 times the period corresponding to the reference frequency of the inverter circuit 312, or approximately 20 to 100 ms.

[0095] In step S19, if the time difference is within the first predetermined time (step S19: YES), the control circuit 35 sets the first protection device 33 to the OFF state to stop the output of AC output power (S20). The control circuit 35 sets the second protection device 34 to the OFF state to stop the input of input power (S21). The control circuit 35 outputs a first abnormality notification (S22). The first abnormality notification indicates that an abnormality has occurred in the refrigeration cycle apparatus 1 that is highly likely to cause a disproportionation reaction. The first abnormality notification is output to, for example, the control circuit and remote controller of the indoor unit 1b. Thereafter, the control circuit 35 stops operation of the compressor 4 (S23).

[0096] In this way, if the detected voltage becomes less than the second voltage (S19: YES) before a predetermined time (first predetermined time) has elapsed since the output of AC output power was resumed after the first waiting time had elapsed (S17), the control circuit 35 stops the output of AC output power (S20) and stops the input of input power (S21).

[0097] If the time difference is not within the first predetermined time in step S19 (step S19: NO), referring to Fig. 6, the control circuit 35 determines whether the time difference is within a second predetermined time that is longer than the first predetermined time (step S24). The second predetermined time is, for example, about 1000 times the period corresponding to the reference frequency of the inverter circuit 312, and is about 200 ms to 1 s.

[0098] If the time difference is within the second predetermined time in step S24 (step S24: YES), the control circuit 35 sets the first protection device 33 to the OFF state and stops the output of AC output power (S25). The control circuit 35 changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power decreases from E to E / 2 (S26). The control circuit 35 outputs a second abnormality notification (S27). The second abnormality notification indicates that an abnormality that is likely to cause a disproportionation reaction has occurred in the refrigeration cycle apparatus 1. The second abnormality notification is output to, for example, the control circuit and remote controller of the indoor unit 1b.

[0099] The control circuit 35 determines whether a fourth standby time has elapsed since the output of AC output power was stopped (S28). The fourth standby time is longer than the first standby time. The fourth standby time is, for example, 60 seconds. When the fourth standby time has elapsed (S28: YES), as shown in FIG. 7 , the control circuit 35 sets the first protection device 33 to the ON state to resume the output of AC output power (S29), thereby resuming operation of the compressor 4 (S30). In this case, the set value of the amplitude of the AC output power remains lowered from E to E / 2.

[0100] In this way, if the detected voltage becomes less than the second voltage before a predetermined time (second predetermined time) has elapsed since the output of the AC output power was resumed after the first standby time (S17), the control circuit 35 stops the output of the AC output power (S25) and reduces the set value of the amplitude of the AC output power (S26).If a fourth standby time longer than the first standby time has elapsed since the output of the AC output power was stopped, the control circuit 35 resumes the output of the AC output power while keeping the set value of the amplitude of the AC output power reduced (S29).

[0101] Thereafter, the control circuit 35 acquires the detected voltage from the voltage detector 32 (S31). The control circuit 35 determines whether the detected voltage is less than the second voltage (S32).

[0102] In step S32, if the detected voltage is less than the second voltage (S32: YES), the process proceeds to step S20 in FIG.

[0103] In step S32, if the detected voltage is not less than the second voltage (S32: NO), the control circuit 35 determines whether the second monitoring time has elapsed since the operation of the compressor 4 was restarted (S33).

[0104] In step S33, if the second monitoring time has elapsed since the operation of the compressor 4 was restarted (S33: YES), the control circuit 35 cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S34), and proceeds to step S11 in FIG. 4.

[0105] In step S33, if the second monitoring time has not elapsed since the operation of the compressor 4 was restarted (S33: NO), the process returns to step S31.

[0106] In steps S31 to S33, if the detected voltage becomes less than the second voltage between the time when the compressor 4 restarts operation and the time when the second monitoring time has elapsed, the process proceeds to step S20 in FIG. 5, and if the detected voltage does not become less than the second voltage between the time when the compressor 4 restarts operation and the time when the second monitoring time has elapsed, the process proceeds to step S34.

[0107] In this way, if the detected voltage does not become less than the second voltage during the second monitoring time from when the output of AC output power is resumed after the fourth waiting time has elapsed (S29) (YES at S33), the control circuit 35 cancels the reduction of the set value of the amplitude of the AC output power (S34). If the detected voltage becomes less than the second voltage before the second monitoring time has elapsed from when the output of AC output power is resumed after the fourth waiting time has elapsed (S29) (YES at S32), the control circuit 35 stops the output of AC output power (S20) and stops the input of input power (S21).

[0108] 6, if the time difference is not within the second predetermined time in step S24 (step S24: NO), referring to Fig. 8, the control circuit 35 determines whether the time difference is within a third predetermined time that is longer than the second predetermined time (step S35). The third predetermined time is, for example, about 10,000 times the period corresponding to the reference frequency of the inverter circuit 312, which is about 2 to 10 seconds.

[0109] In step S35, if the time difference is not within the third predetermined time (step S35: NO), the process returns to step S10, and the control circuit 35 sets the number of abnormalities to 0 (see FIG. 4). In other words, if a sufficient amount of time has passed since the detection of the abnormality, the possibility of the occurrence of a discharge phenomenon is considered low, and therefore the number of abnormalities is reset to 0.

[0110] In step S35, if the time difference is within the third predetermined time (step S35: YES), the control circuit 35 determines whether the number of abnormalities is 2 or less (S36).

[0111] If the number of abnormalities is two or less in step S36 (S36: YES), the control circuit 35 sets the first protection device 33 to the OFF state and stops the output of AC output power (S37). The control circuit 35 outputs a third abnormality notification (S38). The third abnormality notification indicates that an abnormality that may cause a disproportionation reaction has occurred in the refrigeration cycle apparatus 1. The third abnormality notification is output, for example, to the control circuit of the indoor unit 1b and a remote controller. The control circuit 35 determines whether a second standby time has elapsed since the output of AC output power was stopped (S39). The second standby time is longer than the first standby time. The second standby time is, for example, 10 seconds. When the second standby time has elapsed (S39: YES), the control circuit 35 sets the first protection device 33 to the ON state and resumes the output of AC output power (S40), thereby restarting the operation of the compressor 4 (S41). Then, the process returns to step S11.

[0112] In this way, the control circuit 35 stops the output of the AC output power if the detected voltage becomes lower than the second voltage before the predetermined time (third predetermined time) has elapsed since the output of the AC output power was resumed after the first standby time had elapsed (S17). The control circuit 35 resumes the output of the AC output power when the second standby time, which is longer than the first standby time, has elapsed since the output of the AC output power was stopped (S40).

[0113] In step S36, if the number of abnormalities is not two or less (S36: NO), that is, if the number of abnormalities is three or more, the control circuit 35 sets the first protection device 33 to the off state and stops the output of AC output power (S42). The control circuit 35 changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power decreases from E to E / 2 (S43). The control circuit 35 outputs a second abnormality notification (S44).

[0114] The control circuit 35 determines whether a third standby time has elapsed since the output of AC output power was stopped (S45). The third standby time is longer than the second standby time. The third standby time is, for example, 60 seconds. When the third standby time has elapsed (S45: YES), as shown in FIG. 9 , the control circuit 35 sets the first protection device 33 to the ON state to resume the output of AC output power (S46), thereby resuming operation of the compressor 4 (S47). In this case, the set value of the amplitude of the AC output power remains lowered from E to E / 2.

[0115] In this way, if the detected voltage becomes less than the second voltage before a predetermined time (third predetermined time) has elapsed since the output of the AC output power was resumed after the second standby time (S40), the control circuit 35 stops the output of the AC output power (S42) and reduces the set value of the amplitude of the AC output power (S43).If a third standby time, which is longer than the second standby time, has elapsed since the output of the AC output power was stopped, the control circuit 35 resumes the output of the AC output power while keeping the set value of the amplitude of the AC output power reduced (S47).

[0116] Thereafter, the control circuit 35 acquires the detected voltage from the voltage detector 32 (S48), and determines whether the detected voltage is less than the second voltage (S49).

[0117] In step S49, if the detected voltage is less than the second voltage (S49: YES), the process proceeds to step S20 in FIG.

[0118] In step S49, if the detected voltage is not less than the second voltage (S49: NO), the control circuit 35 determines whether the first monitoring time has elapsed since the operation of the compressor 4 was restarted (S50). The first monitoring time may be the same as or different from the second monitoring time in step S33.

[0119] In step S50, if the first monitoring time has elapsed since the operation of the compressor 4 was restarted (S50: YES), the control circuit 35 cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S51), and proceeds to step S11 in FIG. 4.

[0120] In step S50, if the first monitoring time has not elapsed since the operation of the compressor 4 was restarted (S50: NO), the process returns to step S48.

[0121] In steps S48 to S50, if the detected voltage becomes less than the second voltage between the time when the compressor 4 restarts operation and the time when the first monitoring time has elapsed, the process proceeds to step S20 in FIG. 5, and if the detected voltage does not become less than the second voltage between the time when the compressor 4 restarts operation and the time when the first monitoring time has elapsed, the process proceeds to step S51.

[0122] In this way, if the detected voltage does not become less than the second voltage during the first monitoring time from when the output of the AC output power is resumed after the third waiting time has elapsed (S47) (YES at S50), the control circuit 35 cancels the reduction of the set value of the amplitude of the AC output power (S51). If the detected voltage becomes less than the second voltage before the first monitoring time has elapsed from when the output of the AC output power is resumed after the third waiting time has elapsed (S47) (YES at S49), the control circuit 35 stops the output of the AC output power (S20) and stops the input of the input power (S21).

[0123] [1.1.2 Effects, etc.] The control device 3 described above is a control device that controls the refrigeration cycle circuit 2 through which the working medium 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and includes a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2, and a control circuit 35 that stops or limits the operation of the refrigeration cycle circuit 2 when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 or a second state related to the working medium 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0124] In the control device 3, the drive circuit 31 includes a converter circuit 311 that outputs DC output power based on input power from the power source 10 so that the voltage becomes a first voltage, and an inverter circuit 312 that outputs AC output power to the electric motor 42 based on the DC output power. The control device 3 includes a voltage detector 32 that detects the DC output power and outputs a detected voltage indicating the voltage of the DC output power as a second state. The control circuit 35 determines the number of times a discharge phenomenon occurs in the compressor 4 based on the number of times the detected voltage becomes less than a second voltage that is equal to or less than the first voltage. A sign of a disproportionation reaction is when the number of times a discharge phenomenon occurs is equal to or greater than a predetermined number. This configuration enables earlier detection of a sign of a disproportionation reaction in the working medium 20 and enables improved suppression of the disproportionation reaction.

[0125] It can be said that the control device 3 described above executes the following control method. The control method stops or restricts the operation of the refrigeration cycle circuit 2 when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0126] The control method includes determining the number of times that a discharge phenomenon occurs in the compressor 4 based on the second state. A sign of a disproportionation reaction is when the number of times that a discharge phenomenon occurs is equal to or greater than a predetermined number. This configuration enables earlier detection of a sign of a disproportionation reaction of the working fluid 20 and enables improved suppression of the disproportionation reaction.

[0127] The control method executed by the control device 3 can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3 that controls the refrigeration cycle circuit 2 through which the working medium 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and causes the computer system to execute a process to stop or limit the operation of the refrigeration cycle circuit 2 when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 and a second state related to the working medium 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0128] The control device 3 described above controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The control device 3 includes a drive circuit 31 including a converter circuit 311 that outputs DC output power based on input power from a power source 10 so that the voltage becomes a first voltage, and an inverter circuit 312 that outputs AC output power to an electric motor 42 based on the DC output power; a voltage detector 32 that detects the DC output power and outputs a detected voltage indicative of the voltage of the DC output power; and a control circuit 35 that stops or limits operation of the drive circuit 31 when the detected voltage falls below a second voltage that is equal to or lower than the first voltage. This configuration enables earlier detection of a sign of a disproportionation reaction in the working medium 20 and improves suppression of the disproportionation reaction.

[0129] In the control device 3, stopping the operation of the drive circuit 31 includes at least one of stopping the output of AC output power, stopping the output of DC output power, or stopping the input of input power. This configuration enables early detection of a sign of the disproportionation reaction of the working medium 20 and enables improved suppression of the disproportionation reaction.

[0130] In the control device 3, the limitation on the operation of the drive circuit 31 includes at least one of reducing the set value of the amplitude of the AC output power and reducing the set value of the frequency of the AC output power. This configuration enables earlier detection of a sign of the disproportionation reaction of the working fluid 20 and enables improved suppression of the disproportionation reaction.

[0131] In the control device 3, the control circuit 35 stops or limits the operation of the drive circuit 31 in different ways depending on the time difference between the first time when the detected voltage becomes less than the second voltage and the second time when the detected voltage becomes less than the second voltage. This configuration makes it possible to suppress the disproportionation reaction of the working medium 20 even when discharge phenomena occur continuously.

[0132] In the control device 3, the control circuit 35 stops or limits the operation of the drive circuit 31 in different ways depending on the number of times the detected voltage becomes less than the second voltage. This configuration makes it possible to suppress the disproportionation reaction of the working medium 20 even when discharge phenomena occur continuously.

[0133] In the control device 3, the control circuit 35 stops the output of the AC output power when the detected voltage becomes less than the second voltage, and resumes the output of the AC output power when a first standby time has elapsed since the output of the AC output power was stopped. This configuration allows the compressor 4 to continue operating while suppressing the disproportionation reaction of the working medium 20.

[0134] In the control device 3, the control circuit 35 stops the output of the AC output power when the detected voltage becomes less than the second voltage before a predetermined time has elapsed since the output of the AC output power was resumed after the first standby time has elapsed, and resumes the output of the AC output power when a second standby time longer than the first standby time has elapsed since the output of the AC output power was stopped. This configuration allows the compressor 4 to continue operating while suppressing the disproportionation reaction of the working medium 20.

[0135] In the control device 3, when the detected voltage becomes less than the second voltage before a predetermined time has elapsed since the output of the AC output power is resumed after the second standby time has elapsed, the control circuit 35 stops the output of the AC output power and reduces the set value of the amplitude of the AC output power, and when a third standby time longer than the second standby time has elapsed since the output of the AC output power was stopped, the control circuit 35 resumes the output of the AC output power while keeping the set value of the amplitude of the AC output power reduced. This configuration makes it possible to continue operation of the compressor 4 while suppressing the disproportionation reaction of the working medium 20.

[0136] In the control device 3, the control circuit 35 cancels the reduction of the set value of the amplitude of the AC output power if the detected voltage does not become less than the second voltage during the first monitoring time from the resumption of output of the AC output power after the third standby time has elapsed, and stops the output of the AC output power and stops the input of the input power if the detected voltage becomes less than the second voltage before the first monitoring time has elapsed from the resumption of output of the AC output power after the third standby time has elapsed. This configuration allows the compressor 4 to continue operating while suppressing the disproportionation reaction of the working medium 20.

[0137] In the control device 3, when the detected voltage becomes less than the second voltage before a predetermined time has elapsed since the output of the AC output power is resumed after the first standby time has elapsed, the control circuit 35 stops the output of the AC output power and reduces the set value of the amplitude of the AC output power, and when a fourth standby time has elapsed since the output of the AC output power was stopped, the control circuit 35 resumes the output of the AC output power while keeping the set value of the amplitude of the AC output power reduced. This configuration makes it possible to continue operation of the compressor 4 while suppressing the disproportionation reaction of the working medium 20.

[0138] In the control device 3, the control circuit 35 cancels the reduction of the set value of the amplitude of the AC output power if the detected voltage does not become less than the second voltage during the second monitoring time from the resumption of output of the AC output power after the fourth standby time has elapsed, and stops the output of the AC output power and stops the input of the input power if the detected voltage becomes less than the second voltage before the second monitoring time has elapsed from the resumption of output of the AC output power after the fourth standby time has elapsed. This configuration makes it possible to continue operation of the compressor 4 while suppressing the disproportionation reaction of the working medium 20.

[0139] In the control device 3, when the detected voltage becomes less than the second voltage before a predetermined time has elapsed since the output of the AC output power is resumed after the first standby time has elapsed, the control circuit 35 stops the output of the AC output power and stops the input of the input power. This configuration enables earlier detection of a sign of the disproportionation reaction of the working medium 20 and enables improved suppression of the disproportionation reaction.

[0140] In the control device 3, the second voltage is 0.3 to 0.8 times the first voltage. This configuration enables early detection of a sign of the disproportionation reaction of the working fluid 20 and enables improved suppression of the disproportionation reaction.

[0141] The above-described refrigeration cycle apparatus 1 includes the control device 3 and the refrigeration cycle circuit 2. This configuration enables early detection of a sign of a disproportionation reaction of the working fluid 20 and enables improved suppression of the disproportionation reaction.

[0142] In the refrigeration cycle device 1, the ethylene-based fluoroolefin includes an ethylene-based fluoroolefin that undergoes a disproportionation reaction. This configuration makes it possible to improve the suppression of the disproportionation reaction of the working fluid 20.

[0143] In the refrigeration cycle device 1, the ethylene-based fluoroolefin is 1,1,2-trifluoroethylene, trans-1,2-difluoroethylene, cis-1,2-difluoroethylene, 1,1-difluoroethylene, tetrafluoroethylene, or monofluoroethylene. This configuration enables improved suppression of the disproportionation reaction of the working fluid 20.

[0144] In the refrigeration cycle device 1, the working fluid 20 further contains difluoromethane as a refrigerant component. This configuration enables the suppression of the disproportionation reaction of the working fluid 20 to be improved.

[0145] In the refrigeration cycle device 1, the working fluid 20 further contains saturated hydrocarbons. This configuration enables the suppression of the disproportionation reaction of the working fluid 20 to be improved.

[0146] In the refrigeration cycle device 1, the working fluid 20 contains a haloalkane having 1 or 2 carbon atoms as a disproportionation inhibitor that suppresses the disproportionation reaction of ethylene-based fluoroolefins. This configuration enables improved suppression of the disproportionation reaction of the working fluid 20.

[0147] In the refrigeration cycle device 1, the saturated hydrocarbons include n-propane. This configuration enables improved suppression of the disproportionation reaction of the working medium 20.

[0148] The control device 3 described above can be said to execute the following control method. The control method is performed by the control device 3, which controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The control device 3 includes a drive circuit 31 including a converter circuit 311 that outputs DC output power based on input power from a power source 10 so that the voltage becomes a first voltage, and an inverter circuit 312 that outputs AC output power to an electric motor 42 based on the DC output power. The control method stops or limits operation of the drive circuit 31 when the voltage of the DC output power falls below a second voltage that is equal to or lower than the first voltage. This configuration enables earlier detection of a sign of a disproportionation reaction in the working medium 20 and enables improved suppression of the disproportionation reaction.

[0149] The control method executed by the control device 3 can be realized by a computer system executing a program. The program is executed by a computer system included in the control device 3, which controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The control device 3 includes a drive circuit 31 including a converter circuit 311 that outputs DC output power so that the voltage becomes a first voltage based on input power from the power source 10, and an inverter circuit 312 that outputs AC output power to the electric motor 42 based on the DC output power. The program causes the computer system to stop or limit operation of the drive circuit 31 when the voltage of the DC output power becomes less than a second voltage that is equal to or less than the first voltage. This configuration enables earlier detection of a sign of a disproportionation reaction in the working medium 20 and improves suppression of the disproportionation reaction.

[0150] [1.2 Second Embodiment] [1.2.1 Configuration] This embodiment provides a control device, a refrigeration cycle device, a control method, and a program that can improve the accuracy of detection of a disproportionation reaction of a working fluid and enable improved suppression of the disproportionation reaction.

[0151] 10 is a schematic diagram of a compressor 4 and a control device 3A of a refrigeration cycle apparatus according to embodiment 2. The refrigeration cycle apparatus according to embodiment 2 includes the same configuration as the refrigeration cycle apparatus 1 according to embodiment 1, and therefore, FIG. 1 and reference numerals will be used for the same configuration as necessary.

[0152] The control device 3A controls the compressor 4 of the refrigeration cycle circuit 2 .

[0153] 11 is a schematic diagram of the electric motor 42. The electric motor 42 includes, for example, a rotor 421 fixed to the crankshaft of the compression mechanism 41 and a stator 422 disposed around the rotor 421. The stator 422 is configured, for example, by concentrating or dispersing stator windings Wu, Wv, and Ww around a stator core (such as an electromagnetic steel plate) 422a with an insulating material such as insulating paper interposed therebetween. In FIG. 3, the stator 422 includes a total of six stator windings: a stator winding Wu corresponding to two U-phases, a stator winding Ww corresponding to two V-phases, and a stator winding Wwu corresponding to two W-phases.

[0154] The control device 3A includes a drive circuit 31, a light detection device 32A, a first protection device 33, a second protection device 34, and a control circuit 35A.

[0155] The light detection device 32A detects light within the sealed container 40 and outputs the intensity of the light. It is believed that heat and radicals are the causes of the disproportionation reaction of the working medium 20. For example, it is believed that the disproportionation reaction of the working medium 20 progresses when radicals are generated under high temperature and high pressure. The radicals may be generated, for example, by a discharge phenomenon that may occur when some abnormality occurs in the compressor 4 or the drive circuit 31. The present inventors have found that light is generated within the sealed container 40 when a disproportionation reaction occurs in the compressor 4.

[0156] Here, an experiment was carried out to verify whether or not a disproportionation reaction occurs using a working fluid containing 1,1,2-trifluoroethylene (HFO1123).

[0157] In the disproportionation reaction experiment, a sealed pressure vessel (stainless steel sealed vessel (with a window plate), internal volume 50 mL) was equipped with a pressure sensor (GC61 manufactured by Nagano Keiki Co., Ltd.) to measure the internal pressure of the pressure vessel, a thermocouple (PL Thermocouple Ground PL-18-K-A 4-T manufactured by Conax Technologies) to measure the internal temperature of the pressure vessel, and a discharge electrode D to generate a discharge within the pressure vessel. Furthermore, a gas cylinder of 1,1,2-trifluoroethylene was connected so that the pressure could be adjusted. A mantle heater was installed to heat the entire pressure vessel (excluding the window plate), and a ribbon heater (flexible ribbon heater, 1 m, 200 W manufactured by Tokyo Institute of Technology Co., Ltd.) was also installed to heat the piping. A digital camera (commercially available, 240 fps) was installed directly opposite the window plate of the pressure vessel to observe the luminescence behavior of the disproportionation reaction due to the discharge. This constituted an experimental system for the disproportionation reaction.

[0158] Figure 12 is an explanatory diagram of the results of an experiment to verify the occurrence of a disproportionation reaction. Figure 12 shows the main frames of a 4.2 ms / frame image of the behavior of the plasma and reaction fireball generated by a discharge of approximately 0.2 J using 1,1,2-trifluoroethylene as the working fluid, shown from left to right in order of earliest to latest time. In Figure 12, a schematic diagram is shown below the image. The schematic diagram outlines the central portion W of the image above. In the schematic diagram, D indicates the parallel discharge electrodes of the discharge device, and P indicates the discharge location. In Figure 12, the time is shown above the image. The frame in which the plasma generated by the discharge was captured is set to 0 ms, and the time indicates the elapsed time from the discharge.

[0159] At the moment of discharge (0 ms), a pale blue light was observed at the center of the frame (discharge point P). Spectroscopic measurements confirmed that this light was strong between 200 nm and 600 nm. In subsequent frames (4 to 12 ms), light emission was continuously observed at the center of the frame (discharge point P), similar to the 0 ms frame, but the emission color changed to reddish-orange. Spectroscopic measurements also showed that this light emission was particularly strong above 600 nm, with an emission profile similar to blackbody radiation. That is, in the frames from 4 to 12 ms, strong light emission was observed between 600 nm and 2000 nm. After 8 ms, the reddish-orange light emission was observed to weaken, and after 100 ms, almost no light emission was observed, and after approximately 1000 ms, the light returned to a dark (non-luminous) state similar to that before the discharge (-4 ms). When this behavior was investigated by changing the discharge energy, the plasma emission (bluish-white) at 0 ms appeared in all cases and disappeared within 4 ms, and the emission intensity increased with increasing discharge energy. On the other hand, the duration of the emission (reddish-orange) of the subsequent fireball varied between several ms and several tens of ms and increased with increasing discharge energy. The intensity of the reddish-orange emission appearing in the 8 ms frame also increased slightly with increasing discharge energy.

[0160] As shown in Figure 12, even when a reddish-orange reaction fireball was generated, spontaneous reaction propagation did not cause flame propagation throughout the reactor when the discharge energy was low, around 0.2 J. That is, even when plasma (0 ms) or a reaction fireball (4 to several tens of ms) was generated and emitted light, if the intensity of the light was slight, reaction propagation throughout the vessel did not occur. In addition, there were differences in the intensity and duration of the visible light emitted by plasma and the visible to near-infrared light emitted by the reaction fireball. Although the visible light emission was low in intensity, it was observed in all discharge phenomena. In contrast, the visible to near-infrared light emission tended to have a high cumulative emission intensity due to its long duration, but was difficult to observe in mild discharges with low discharge energy. Therefore, in order to suppress the propagation of the disproportionation reaction, it is preferable to utilize the characteristics of each emission to detect mild light emission states early and with high sensitivity.

[0161] Thus, it was confirmed that at least a portion of the wavelengths of light emitted from the fireball generated by the disproportionation reaction as a light source falls within the near-infrared region or the range of greater than 600 nm and less than 2000 nm. The light emitted from the fireball generated by the disproportionation reaction has a relatively long emission time and a relatively large amount of light. In other words, although the light emitted from the fireball generated by the disproportionation reaction is observed in the early stages of the disproportionation reaction, it is easy to detect. Therefore, the photodetector 32A detects first light having a wavelength greater than 600 nm and less than 2000 nm. Hereinafter, for simplicity of explanation, light having a wavelength greater than 600 nm and less than 2000 nm will be referred to as "first light." The wavelength of the first light is mainly within the near-infrared wavelength region.

[0162] 11 , the photodetector 32A includes a plurality of photodetectors 321A, 322A that detect the first light. The plurality of photodetectors 321A, 322A are disposed within the sealed container 40. In the compressor 4, the disproportionation reaction may be caused by a discharge phenomenon in the stator winding or sliding of the crankshaft of the compression mechanism 41. Therefore, the photodetector 321A is disposed on the first end side (the front side of the paper) in the direction of the rotation axis A11 of the electric motor 42. The photodetector 322A is disposed on the second end side (the rear side of the paper) in the direction of the rotation axis A11 of the electric motor 42. This enables improved accuracy in detecting the disproportionation reaction. In particular, in FIG. 11 , one photodetector 321A and one photodetector 322A are arranged for each of the six stator windings: the stator windings Wu corresponding to two U phases, the stator windings Ww corresponding to two V phases, and the stator windings Wwu corresponding to two W phases. Therefore, the photodetectors 321A and 322A are arranged on both sides of each stator winding in the direction of the rotation axis A11 of the electric motor 42. In this configuration, the photodetectors 321A and 322A are arranged on the first end or second end in the direction of the rotation axis A11 of the electric motor 42, where a discharge phenomenon is more likely to occur. Therefore, the required sensitivity can be achieved while reducing the number of photodetectors 321A and 322A. In particular, in this embodiment, the photodetectors 321A and 322A are arranged on the first end or second end in the direction of the rotation axis A11 of the electric motor 42 with respect to the stator windings, thereby enabling efficient detection of light resulting from a discharge phenomenon.

[0163] The photodetectors 321A and 322A may be selected from, for example, a PN photodiode, a PIN photodiode, and an avalanche photodiode. In this embodiment, the photodetectors 321A and 322A are, for example, InGaAs photodiodes or PbS photodiodes.

[0164] The control circuit 35A can be realized, for example, by a computer system including at least one processor (microprocessor) and one or more memories. The computer system may also include one or more A / D converters. For example, the one or more A / D converters are used to convert the detected voltage from the light detection device 32A from analog to digital format. The control circuit 35A, like the control circuit 35, controls the drive circuit 31, the first protection device 33, and the second protection device 34.

[0165] The control circuit 35A further executes processing for suppressing a disproportionation reaction of the working fluid 20 circulating through the refrigeration cycle circuit 2, based on the intensity of the light output from the photodetector 32A. As described above, the inventors have found that when a disproportionation reaction occurs in the compressor 4, the first light is generated in the sealed container 40. From this perspective, the control circuit 35A determines whether a disproportionation reaction has occurred based on the intensity of the first light in the sealed container 40, and if it is determined that a disproportionation reaction has occurred, stops or limits the operation of the drive circuit 31 in order to suppress the progress of the disproportionation reaction of the working fluid circulating through the refrigeration cycle circuit 2.

[0166] In the control device 3A described above, the light detection device 32A detects light inside the sealed container 40 of the compressor 4 of the refrigeration cycle circuit 2 and outputs the intensity of the light as a second state. When the control circuit 35A detects a sign of a disproportionation reaction based on the second state related to the working medium 20, it stops or limits the operation of the refrigeration cycle circuit 2. Here, the control circuit 35A determines the number of times that the working medium 20 in the compressor 4 emits light, based on the number of times that the light intensity exceeds a light threshold. A sign of a disproportionation reaction occurs when the number of times that the working medium 20 emits light is equal to or greater than a predetermined number.

[0167] The control device 3A detects the disproportionation reaction based on the intensity of light generated in the sealed container 40, rather than on a change in the current actually flowing from the drive circuit 31 to the electric motor 42. Therefore, the control device 3A can detect the disproportionation reaction without being affected by the physical or electrical state of the circuits constituting the refrigeration cycle apparatus 1. If the accuracy of detection of the disproportionation reaction of the working fluid 20 can be improved in this way, the progress of the disproportionation reaction can be more accurately suppressed, thereby enabling improved suppression of the disproportionation reaction.

[0168] In this embodiment, the control circuit 35A stops or limits the operation of the drive circuit 31 when the intensity of the first light exceeds a first light threshold. In this embodiment, the photodetector 32A includes multiple photodetectors 321A and 322A. The control circuit 35A stops or limits the operation of the drive circuit 31 when at least one of the intensities of the first light from the multiple photodetectors 321A and 322A exceeds the first light threshold. The first light threshold is set to determine whether a disproportionation reaction has occurred. The first light threshold is at least three times the intensity of the first light obtained from the photodetector 32A when the motor 42 is driven at rated speed. The intensity of the first light obtained from the photodetector 32A when the motor 42 is driven at rated speed corresponds to, for example, a baseline current appearing in the photodetector 32A when the motor 42 is driven at rated speed.

[0169] In this embodiment, a first threshold, a second threshold smaller than the first threshold, and a third threshold smaller than the second threshold are used as thresholds for the first light. However, the third threshold is greater than the lower detection limit of the first light. The lower detection limit of the first light is a reference value for determining whether the first light itself is present. By using different thresholds, the control circuit 35A stops or limits the operation of the drive circuit 31 in different ways depending on the intensity of the first light. In particular, the control circuit 35A executes processing that suppresses the disproportionation reaction to a higher degree as the intensity of the first light increases. This allows the control device 3A to appropriately suppress the disproportionation reaction.

[0170] The process for suppressing the disproportionation reaction includes, for example, a first process and a second process. The first process is a process of lowering the set value of the amplitude of the AC output power, stopping at least one of the output of the AC output power and the input of the input power if the light intensity exceeds a determination value that is equal to or less than the light threshold before the monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power, and canceling the reduction in the set value of the amplitude of the AC output power if the light intensity does not exceed the determination value even after the monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power. The second process is a process of stopping at least one of the output of the AC output power and the input of the input power. The degree of suppression of the disproportionation reaction increases in the order of the second process and the first process. In the first process, the longer the monitoring time, the higher the degree of suppression of the disproportionation reaction.

[0171] Next, an example of the operation of the control circuit 35A of the control device 3A will be briefly described with reference to Figures 13 to 15. Each of Figures 13 to 15 is a part of a flowchart of the operation of the control circuit 35A of the control device 3A, and Figures 13 to 15 are combined to complete one flowchart.

[0172] 13, the control circuit 35A causes the drive circuit 31 to output AC output power to the electric motor 42 based on the input power of the power supply 10, thereby driving the compressor 4.

[0173] The control circuit 35A acquires the intensity of the first light from the light detection device 32A (S110), and determines whether the intensity of the first light exceeds a first threshold (S111).

[0174] In step S111, if the intensity of the first light exceeds the first threshold (step S111: YES), the control circuit 35A sets the first protection device 33 to the OFF state to stop the output of AC output power (S112). The control circuit 35A sets the second protection device 34 to the OFF state to stop the input of input power (S113). The control circuit 35A outputs a first abnormality notification (S114). The first abnormality notification indicates that there is a very high possibility that a disproportionation reaction is occurring in the refrigeration cycle apparatus 1. Thereafter, the control circuit 35A stops the operation of the compressor 4 (S115).

[0175] In this way, when the intensity of the first light exceeds the first threshold value of the first light, the control circuit 35A stops the output of AC output power and stops the input of input power.

[0176] In step S111, if the intensity of the first light does not exceed the first threshold (step S111: NO), referring to FIG. 14, the control circuit 35A determines whether the intensity of the first light exceeds a second threshold that is smaller than the first threshold (step S116).

[0177] In step S116, if the intensity of the first light exceeds the second threshold (step S116: YES), the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power decreases from E to E / 2 (S117). The control circuit 35A outputs a second abnormality notification (S118). The second abnormality notification indicates that a disproportionation reaction is likely occurring in the refrigeration cycle apparatus 1.

[0178] Thereafter, the control circuit 35A acquires the intensity of the first light from the light detection device 32A (S119). The control circuit 35A determines whether the intensity of the first light exceeds a first determination value (S120). The first determination value is equal to or less than the second threshold value. In this embodiment, the first determination value is smaller than the second threshold value.

[0179] In step S120, if the intensity of the first light exceeds the first determination value (S120: YES), the process proceeds to step S112 in FIG.

[0180] If the intensity of the first light does not exceed the first determination value (S120: NO), the control circuit 35A determines whether a first monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced (S121). The first monitoring time is, for example, approximately 100,000 times the period corresponding to the reference frequency of the inverter circuit 312, which is approximately 20 seconds to 100 seconds.

[0181] In step S121, if the first monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power (S121: YES), the control circuit 35A cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S122), and proceeds to step S110 in FIG. 13.

[0182] In step S121, if the first monitoring time has not elapsed since the set value of the amplitude of the AC output power was reduced (S121: NO), the process returns to step S119.

[0183] In steps S119 to S121, if the intensity of the first light exceeds the first judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the first monitoring time has elapsed, the process proceeds to step S112 in FIG. 13, and if the intensity of the first light does not exceed the first judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the first monitoring time has elapsed, the process proceeds to step S122.

[0184] In this way, if the intensity of the first light does not exceed the first determination value during the first monitoring time period from the reduction of the set value of the amplitude of the AC output power (S117) (YES at S121), the control circuit 35A cancels the reduction of the set value of the amplitude of the AC output power (S122). If the intensity of the first light exceeds the first determination value before the first monitoring time period has elapsed from the reduction of the set value of the amplitude of the AC output power (S117) (YES at S120), the control circuit 35A stops the output of the AC output power (S113) and stops the input of the input power (S114).

[0185] If the intensity of the first light does not exceed the second threshold value in step S116 (step S116: NO), referring to Fig. 15, the control circuit 35A determines whether the intensity of the first light exceeds a third threshold value that is smaller than the second threshold value (step S123). In the present embodiment, the third threshold value is equal to the first determination value.

[0186] In step S123, if the intensity of the first light exceeds the third threshold (step S123: YES), the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power decreases from E to E / 2 (S124). The control circuit 35A outputs a third abnormality notification (S125). The third abnormality notification indicates that a disproportionation reaction may be occurring in the refrigeration cycle apparatus 1.

[0187] Thereafter, the control circuit 35A acquires the intensity of the first light from the light detection device 32A (S126). The control circuit 35A determines whether the intensity of the first light exceeds a second determination value (S127). The second determination value is equal to or less than a third threshold value. In this embodiment, the second determination value is equal to the third threshold value.

[0188] In step S127, if the intensity of the first light exceeds the second determination value (S127: YES), the process proceeds to step S112 in FIG.

[0189] If the intensity of the first light does not exceed the second determination value (S127: NO), the control circuit 35A determines whether a second monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced (S128). The second monitoring time is shorter than the first monitoring time. The second monitoring time is, for example, approximately 10,000 times the period corresponding to the reference frequency of the inverter circuit 312, which is approximately 2 seconds to 10 seconds.

[0190] In step S128, if the second monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power (S128: YES), the control circuit 35A cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S129), and proceeds to step S10 in FIG. 13.

[0191] In step S128, if the second monitoring time has not elapsed since the set value of the amplitude of the AC output power was reduced (S128: NO), the process returns to step S126.

[0192] In steps S126 to S128, if the intensity of the first light exceeds the second judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the second monitoring time has elapsed, the process proceeds to step S112 in FIG. 13, and if the intensity of the first light does not exceed the second judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the second monitoring time has elapsed, the process proceeds to step S129.

[0193] In this way, if the intensity of the first light does not exceed the second determination value during the second monitoring time period from the reduction of the set value of the amplitude of the AC output power (S124) (YES at S128), the control circuit 35A cancels the reduction of the set value of the amplitude of the AC output power (S129). If the intensity of the first light exceeds the second determination value before the second monitoring time period has elapsed from the reduction of the set value of the amplitude of the AC output power (S124) (YES at S127), the control circuit 35A stops the output of the AC output power (S113) and stops the input of the input power (S114).

[0194] [1.2.2 Effects, etc.] The control device 3A described above is a control device that controls the refrigeration cycle circuit 2 through which the working medium 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and includes a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2, and a control circuit 35A that stops or limits the operation of the refrigeration cycle circuit 2 when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 or a second state related to the working medium 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0195] The control device 3A includes a light detection device 32A that detects light inside the sealed container 40 and outputs the light intensity as a second state. The control circuit 35A determines the number of times that the working medium 20 emits light in the compressor 4 based on the number of times that the light intensity exceeds a light threshold. A sign of a disproportionation reaction is when the number of times that the working medium 20 emits light exceeds a predetermined number. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0196] It can be said that the control device 3A described above executes the following control method. The control method stops or limits the operation of the refrigeration cycle circuit 2 when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0197] The control method includes determining the number of times that the working medium 20 emits light in the compressor 4 based on the second state. A sign of the disproportionation reaction is that the number of times that the working medium 20 emits light is equal to or greater than a predetermined number. This configuration can improve the accuracy of detecting the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0198] The control method executed by the control device 3A can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3A that controls the refrigeration cycle circuit 2 through which the working fluid 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and causes the computer system to execute a process to stop or limit the operation of the refrigeration cycle circuit 2 when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2 and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0199] The control device 3A described above controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The compressor 4 includes a sealed container 40 that forms a flow path for the working medium 20, a compression mechanism 41 located within the sealed container 40 and compressing the working medium 20, and an electric motor 42 located within the sealed container 40 and operating the compression mechanism 41. The control device 3A includes a drive circuit 31 that drives the electric motor 42, a light detection device 32A that detects light within the sealed container 40 and outputs the light intensity, and a control circuit 35A that stops or limits the operation of the drive circuit 31 when the light intensity exceeds a light threshold. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0200] In the control device 3A, the photodetector 32A includes a plurality of photodetectors 321A, 322A that detect light inside the sealed container 40. The plurality of photodetectors 321A, 322A are arranged inside the sealed container 40 on at least one of a first end side and a second end side in the direction of the rotation axis A11 of the electric motor 42. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0201] In the control device 3A, the photodetector 32A includes at least one of a PN photodiode, a PIN photodiode, and an avalanche photodiode. This configuration can improve the accuracy of detecting the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0202] In the control device 3A, the light has a wavelength of more than 600 nm and not more than 2000 nm. This configuration makes it possible to stop or limit the operation of the drive circuit 31 based on the light from the fireball generated by the disproportionation reaction.

[0203] In the control device 3A, the light threshold is three times or more the intensity of light obtained from the light detection device 32A when the electric motor 42 is driven at rated speed. This configuration enables improvement in the accuracy of the determination of whether or not to suppress the disproportionation reaction.

[0204] In the control device 3A, the drive circuit 31 includes a converter circuit 311 that outputs DC output power based on input power from the power source 10, and an inverter circuit 312 that outputs AC output power to the electric motor 42 based on the DC output power. Stopping the operation of the drive circuit 31 includes at least one of stopping the output of AC output power, stopping the output of DC output power, or stopping the input of input power. Restricting the operation of the drive circuit 31 includes at least one of reducing the set value of the amplitude of the AC output power or reducing the set value of the frequency of the AC output power. This configuration enables improved suppression of the disproportionation reaction.

[0205] In the control device 3A, the control circuit 35A restricts the operation of the drive circuit 31 when the light intensity exceeds the light threshold. The control circuit 35A stops the operation of the drive circuit 31 when the light intensity exceeds a judgment value that is equal to or less than the light threshold before the monitoring time has elapsed since the restriction on the operation of the drive circuit 31. The control circuit 35A releases the restriction on the operation of the drive circuit 31 if the light intensity does not exceed the judgment value even after the monitoring time has elapsed since the restriction on the operation of the drive circuit 31. This configuration allows the compressor 4 to continue operating while suppressing the disproportionation reaction of the working medium 20.

[0206] The refrigeration cycle apparatus 1 described above includes the control device 3A and the refrigeration cycle circuit 2. This configuration can improve the accuracy of detecting the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0207] The control device 3A described above can be said to execute the following control method. The control method is executed by the control device 3A, which controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The compressor 4 includes a sealed container 40 that forms a flow path for the working medium 20, a compression mechanism 41 located within the sealed container 40 and compressing the working medium 20, and an electric motor 42 located within the sealed container 40 and operating the compression mechanism 41. The control device 3A includes a drive circuit 31 that drives the electric motor 42. The control method stops or limits operation of the drive circuit 31 when the light intensity within the sealed container 40 exceeds a light threshold. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enables improved suppression of the disproportionation reaction.

[0208] The control method executed by the control device 3A can be realized by a computer system executing a program. The program is executed by a computer system included in the control device 3A, which controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The compressor 4 includes a sealed container 40 that forms a flow path for the working medium 20, a compression mechanism 41 located within the sealed container 40 and compressing the working medium 20, and an electric motor 42 located within the sealed container 40 and operating the compression mechanism 41. The control device 3A includes a drive circuit 31 that drives the electric motor 42. The program causes the computer system to stop or limit operation of the drive circuit 31 when the light intensity within the sealed container 40 exceeds a light threshold. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0209] [1.3 Third Embodiment] [1.3.1 Configuration] The refrigeration cycle apparatus according to the third embodiment includes a refrigeration cycle circuit 2 and a control device 3A, similar to the refrigeration cycle apparatus 1 according to the second embodiment. However, the configurations of the photodetector 32A and the control circuit 35A of the control device 3A are different from those of the second embodiment.

[0210] In this embodiment, the photodetector 32A also detects light within the sealed container 40 and outputs the light intensity, but the wavelength of the detected light differs from that of the first embodiment. The inventors discovered that light is generated within the sealed container 40 when a discharge occurs in the compressor 4. It was confirmed that this light originates from plasma generated by a discharge, and that at least a portion of its wavelength falls within the visible light range or the range of 200 nm to 600 nm. Although the light generated by a discharge has a relatively short emission time and a relatively small amount of light, it can be observed before the disproportionation reaction occurs. Therefore, in terms of suppressing the disproportionation reaction, it may be preferable to the first light (light with a wavelength greater than 600 nm and less than 2000 nm) of the first embodiment. Therefore, the photodetector 32A detects second light with a wavelength of 200 nm to 600 nm. Hereinafter, for simplicity of explanation, light with a wavelength of 200 nm to 600 nm will be referred to as second light. The wavelength of the second light falls within a wavelength range that mainly includes ultraviolet light and visible light.

[0211] In the second embodiment, the photodetector device 32A includes a plurality of photodetectors 321A and 322A that detect the second light. The photodetectors 321A and 322A may be selected from, for example, PN photodiodes, PIN photodiodes, and avalanche photodiodes. In the present embodiment, the photodetectors 321A and 322A are, for example, Si photodiodes or Ge photodiodes.

[0212] The control circuit 35A executes processing for suppressing the disproportionation reaction of the working fluid 20 circulating through the refrigeration cycle circuit 2, based on the intensity of the light output from the light detection device 32A. As described above, the inventors have found that the second light is generated within the sealed container 40 when a discharge phenomenon occurs in the compressor 4. From this perspective, the control circuit 35A determines whether a discharge phenomenon has occurred based on the intensity of the second light within the sealed container 40, and if it determines that a discharge phenomenon has occurred, stops or limits the operation of the drive circuit 31 in order to suppress the progress of the disproportionation reaction of the working fluid circulating through the refrigeration cycle circuit 2.

[0213] In this embodiment, the control circuit 35A stops or limits the operation of the drive circuit 31 when the intensity of the second light exceeds a second light threshold. Because the photodetector 32A includes multiple photodetectors 321A and 322A, the control circuit 35A stops or limits the operation of the drive circuit 31 when at least one of the second light intensities from the multiple photodetectors 321A and 322A exceeds the second light threshold. The second light threshold is set to determine whether a discharge phenomenon has occurred. The second light threshold is at least three times the intensity of the second light obtained from the photodetector 32A when the motor 42 is driven at its rated speed. The intensity of the second light obtained from the photodetector 32A when the motor 42 is driven at its rated speed corresponds to, for example, a baseline current appearing in the photodetector 32A when the motor 42 is driven at its rated speed.

[0214] In this embodiment, a fourth threshold and a fifth threshold smaller than the fourth threshold are used as thresholds for the second light. However, the fifth threshold is greater than the lower detection limit of the second light. The lower detection limit of the second light is a reference value for determining whether the second light itself is present. By using different thresholds, the control circuit 35A stops or restricts the operation of the drive circuit 31 in different ways depending on the intensity of the second light. In particular, the control circuit 35A executes processing that suppresses the disproportionation reaction to a higher degree as the intensity of the second light increases. This allows the control device 3A to appropriately suppress the disproportionation reaction.

[0215] Next, an example of the operation of the control circuit 35A of the control device 3A in embodiment 2 will be briefly described with reference to Figures 16 to 18. Each of Figures 16 to 18 is a part of a flowchart of the operation of the control circuit 35A of the control device 3A, and Figures 16 to 18 are combined to complete one flowchart.

[0216] 16, the control circuit 35A causes the drive circuit 31 to output AC output power to the motor 42 based on the input power of the power supply 10, thereby driving the compressor 4.

[0217] The control circuit 35A acquires the intensity of the second light from the light detection device 32A (S130), and determines whether the intensity of the second light exceeds a fourth threshold (S131).

[0218] In step S131, if the intensity of the second light exceeds the fourth threshold (step S131: YES), the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power is reduced from E to E / 2 (S132). The control circuit 35A outputs a fourth abnormality notification (S133). The fourth abnormality notification indicates that there is a high possibility that a discharge phenomenon is occurring in the refrigeration cycle apparatus 1. The fourth abnormality notification is output to, for example, the control circuit and remote controller of the indoor unit 1b.

[0219] Thereafter, the control circuit 35A acquires the intensity of the second light from the light detection device 32A (S134). The control circuit 35A determines whether the intensity of the second light exceeds a third determination value (S135). The third determination value is equal to or less than a fourth threshold value. In this embodiment, the third determination value is smaller than the fourth threshold value.

[0220] In step S135, if the intensity of the second light exceeds the third determination value (S135: YES), referring to FIG. 17 , the control circuit 35A sets the first protection device 33 to the OFF state to stop the output of AC output power (S138). The control circuit 35A sets the second protection device 34 to the OFF state to stop the input of input power (S139). The control circuit 35A outputs a fifth abnormality notification (S114). The fifth abnormality notification indicates that there is a very high possibility that a discharge phenomenon is occurring in the refrigeration cycle apparatus 1. Thereafter, the control circuit 35A stops operation of the compressor 4 (S141).

[0221] 16. In step S135, if the intensity of the second light does not exceed the third determination value (S135: NO), the control circuit 35A determines whether a third monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced (S136). The third monitoring time is, for example, approximately 100,000 times the period corresponding to the reference frequency of the inverter circuit 312, which is approximately 20 to 100 seconds.

[0222] In step S136, if the third monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power (S136: YES), the control circuit 35A cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S137), and proceeds to step S130.

[0223] In step S136, if the third monitoring time has not elapsed since the set value of the amplitude of the AC output power was decreased (S136: NO), the process returns to step S134.

[0224] In steps S134 to S136, if the intensity of the second light exceeds the third judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the third monitoring time has elapsed, the process proceeds to step S138 in FIG. 17, and if the intensity of the second light does not exceed the third judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the third monitoring time has elapsed, the process proceeds to step S137.

[0225] In this way, the control circuit 35A stops the setting of the amplitude of the AC output power when the intensity of the second light exceeds the fourth threshold value of the second light (S32). If the intensity of the second light does not exceed the third determination value during the third monitoring time from the reduction of the setting of the amplitude of the AC output power (S132) (YES in S136), the control circuit 35A cancels the reduction of the setting of the amplitude of the AC output power (S137). If the intensity of the second light exceeds the third determination value before the third monitoring time has elapsed since the reduction of the setting of the amplitude of the AC output power (S132) (YES in S135), the control circuit 35A stops the output of the AC output power (S138) and stops the input of the input power (S139).

[0226] In step S131, if the intensity of the second light does not exceed the fourth threshold (step S131: NO), referring to Figure 18, the control circuit 35A determines whether the intensity of the second light exceeds a fifth threshold that is smaller than the fourth threshold (step S142).

[0227] In step S142, if the intensity of the second light exceeds the fourth threshold (step S142: YES), the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power is reduced from E to E / 2 (S143). The control circuit 35A outputs a sixth abnormality notification (S144). The sixth abnormality notification indicates that a discharge phenomenon may be occurring in the refrigeration cycle apparatus 1. The sixth abnormality notification is output to, for example, the control circuit and remote controller of the indoor unit 1b.

[0228] The control circuit 35A then acquires the intensity of the second light from the light detection device 32A (S145). The control circuit 35A determines whether the intensity of the second light exceeds a fourth determination value (S146). The fourth determination value is equal to or less than a fourth threshold value. In this embodiment, the fourth determination value is equal to the fourth threshold value.

[0229] In step S146, if the intensity of the second light exceeds the fourth determination value (S146: YES), the process proceeds to step S138 in FIG.

[0230] If the intensity of the second light does not exceed the fourth determination value (S146: NO), the control circuit 35A determines whether a fourth monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced (S147). The fourth monitoring time is shorter than the third monitoring time. The fourth monitoring time is, for example, approximately 10,000 times the period corresponding to the reference frequency of the inverter circuit 312, which is approximately 2 seconds to 10 seconds.

[0231] In step S147, if the fourth monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power (S147: YES), the control circuit 35A cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S148), and proceeds to step S130 in FIG. 16.

[0232] In step S147, if the fourth monitoring time has not elapsed since the set value of the amplitude of the AC output power was reduced (S147: NO), the process returns to step S145.

[0233] In steps S145 to S147, if the intensity of the second light exceeds the fourth judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the fourth monitoring time has elapsed, the process proceeds to step S138 in FIG. 17, and if the intensity of the second light does not exceed the fourth judgment value between the time when the set value of the amplitude of the AC output power is reduced and the time when the fourth monitoring time has elapsed, the process proceeds to step S148.

[0234] In this way, if the intensity of the second light does not exceed the fourth determination value during the fourth monitoring time period from the reduction of the set value of the amplitude of the AC output power (S143) (YES at S147), the control circuit 35A cancels the reduction of the set value of the amplitude of the AC output power (S148). If the intensity of the second light exceeds the fourth determination value before the elapse of the fourth monitoring time period from the reduction of the set value of the amplitude of the AC output power (S143) (YES at S146), the control circuit 35A stops the output of the AC output power (S138) and stops the input of the input power (S139).

[0235] [1.3.2 Effects, etc.] The control device 3A described above controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The compressor 4 includes a sealed container 40 that forms a flow path for the working medium 20, a compression mechanism 41 located within the sealed container 40 and compressing the working medium 20, and an electric motor 42 located within the sealed container 40 and operating the compression mechanism 41. The control device 3A includes a drive circuit 31 that drives the electric motor 42, a light detection device 32A that detects light within the sealed container 40 and outputs the light intensity, and a control circuit 35A that stops or limits the operation of the drive circuit 31 when the light intensity exceeds a light threshold. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0236] In the control device 3A, the light has a wavelength of 200 nm or more and 600 nm or less. This configuration makes it possible to stop or limit the operation of the drive circuit 31 based on light caused by a discharge phenomenon that may cause a disproportionation reaction.

[0237] [1.4 Fourth embodiment] [1.4.1 Configuration] The refrigeration cycle apparatus according to the fourth embodiment includes a refrigeration cycle circuit 2 and a control device 3A, similar to the refrigeration cycle apparatus 1 according to the second embodiment. However, the configurations of the photodetector 32A and the control circuit 35A of the control device 3A are different from those of the second embodiment.

[0238] In this embodiment, the optical detection device 32A also detects light within the sealed container 40 and outputs the light intensity, but detects two wavelengths of light. As described above, the first light has a light source that is a fireball generated by the disproportionation reaction, and at least a portion of its wavelength falls within the near-infrared region or the range of greater than 600 nm and less than 2000 nm. The first light tends to have a relatively long emission time and a relatively large emission amount, but because it is light from a fireball generated by the disproportionation reaction, it is preferable to take measures against the disproportionation reaction promptly. On the other hand, the second light has a light source that is plasma generated by a discharge phenomenon, and at least a portion of its wavelength falls within the visible light region or the range of greater than 200 nm and less than 600 nm. Compared to the first light, the second light has a relatively short emission time and a relatively small emission amount, but because it can be observed before the disproportionation reaction occurs, it can suppress the disproportionation reaction at an earlier stage.

[0239] Therefore, in this embodiment, the light detection device 32A detects both the first light having a wavelength of more than 600 nm and not more than 2000 nm, and the second light having a wavelength of not less than 200 nm and not more than 600 nm.

[0240] In the fourth embodiment, the photodetector 32A includes a plurality of photodetectors 321A and 322A that detect the first light and a plurality of photodetectors 321A and 322A that detect the second light. Examples of the photodetectors 321A and 322A are as described in the second and third embodiments.

[0241] The control circuit 35A executes a process for suppressing the disproportionation reaction of the working medium 20 circulating through the refrigeration cycle circuit 2 based on the intensity of the first light or the second light output from the photodetector 32A.

[0242] The control circuit 35A stops or restricts the operation of the drive circuit 31 in different ways depending on whether the intensity of the first light exceeds the first light threshold or the intensity of the second light exceeds the second light threshold.

[0243] The thresholds for the first light include a first threshold, a second threshold that is lower than the first threshold, and a third threshold that is lower than the second threshold. The thresholds for the second light include a fourth threshold and a fifth threshold that is lower than the fourth threshold. The control circuit 35A stops operation of the drive circuit 31 when the intensity of the first light exceeds the first threshold. The control circuit 35A stops operation of the drive circuit 31 when the intensity of the first light exceeds the second threshold and the intensity of the second light exceeds the fifth threshold. The control circuit 35A stops operation of the drive circuit 31 when the intensity of the first light exceeds the third threshold and the intensity of the second light exceeds the fourth threshold. The control circuit 35A restricts operation of the drive circuit 31 when the intensity of the first light exceeds the third threshold and the intensity of the second light exceeds the fifth threshold. The control circuit 35A restricts operation of the drive circuit 31 when the intensity of the first light is equal to or lower than the third threshold and the intensity of the second light exceeds the fifth threshold.

[0244] Next, an example of the operation of the control circuit 35A of the control device 3A in embodiment 3 will be briefly described with reference to Figures 19 to 26. Each of Figures 19 to 26 is a part of a flowchart of the operation of the control circuit 35A of the control device 3A, and Figures 19 to 26 are combined to complete one flowchart.

[0245] 19, the control circuit 35A causes the drive circuit 31 to output AC output power to the electric motor 42 based on the input power of the power supply 10, thereby driving the compressor 4.

[0246] Steps S150 to S155 in Fig. 19 are the same as steps S110 to S155 in Fig. 12. That is, the control circuit 35A stops the operation of the drive circuit 31 when the intensity of the first light exceeds the first threshold.

[0247] In step S151, if the intensity of the first light does not exceed the first threshold (step S151: NO), referring to FIG. 20, the control circuit 35A determines whether the intensity of the first light exceeds a second threshold that is smaller than the first threshold (step S156).

[0248] If the intensity of the first light exceeds the second threshold in step S156 (step S156: YES), the control circuit 35A acquires the intensity of the second light from the light detection device 32A (S157).The control circuit 35A determines whether the intensity of the second light exceeds the lower detection limit (S158).

[0249] In step S158, if the intensity of the second light exceeds the lower detection limit of the second light (step S158: YES), the process proceeds to step S152. In other words, if the intensity of the first light is equal to or less than the first threshold but exceeds the second threshold, and the second light is detected, the control circuit 35A stops the operation of the drive circuit 31, just as when the intensity of the first light exceeds the first threshold.

[0250] If, in step S158, the intensity of the second light does not exceed the second light detection lower limit (step S158: NO), referring to FIG. 21, the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power is reduced from E to E / 2 (S159). Steps S160 to S164 in FIG. 21 are the same as steps S118 to S122 in FIG. 14, respectively. If, in step S162 in FIG. 21, the intensity of the first light exceeds the first determination value, the process proceeds to step S152 in FIG. 19. After step S164 in FIG. 21, the process proceeds to step S150 in FIG. 19.

[0251] In step S156 of Figure 20, if the intensity of the first light does not exceed the second threshold (step S156: NO), referring to Figure 22, the control circuit 35A determines whether the intensity of the first light exceeds a third threshold that is smaller than the second threshold (step S165).

[0252] If the intensity of the first light exceeds the third threshold in step S165 (step S165: YES), the control circuit 35A acquires the intensity of the second light from the light detection device 32A (S166).The control circuit 35A determines whether the intensity of the second light exceeds the lower detection limit of the second light (S167).

[0253] If, in step S167, the intensity of the second light does not exceed the second light detection lower limit (step S167: NO), referring to FIG. 23, the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power is reduced from E to E / 2 (S168). Steps S169 to S173 in FIG. 23 are the same as steps S125 to S129 in FIG. 15, respectively. If, in step S171 in FIG. 23, the intensity of the first light exceeds the second determination value, the process proceeds to step S152 in FIG. 19. After step S173 in FIG. 23, the process proceeds to step S150 in FIG. 19.

[0254] In step S167 of Figure 22, if the intensity of the second light exceeds the lower detection limit value of the second light (step S167: YES), referring to Figure 24, the control circuit 35A determines whether the intensity of the second light exceeds the fourth threshold value (S174).

[0255] In step S174, if the intensity of the second light exceeds the fourth threshold (S174: YES), the process proceeds to step S152 in FIG.

[0256] In step S174, if the intensity of the second light does not exceed the fourth threshold (step S174: NO), the control circuit 35A determines whether the intensity of the second light exceeds a fifth threshold that is lower than the fourth threshold (S175).

[0257] In step S175, if the intensity of the second light exceeds the fifth threshold (S175: YES), the control circuit 35A changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power is reduced from E to E / 2 (S176). The control circuit 35A outputs a seventh abnormality notification (S177). The seventh abnormality notification indicates that a disproportionation reaction and a discharge phenomenon may be occurring in the refrigeration cycle apparatus 1. The seventh abnormality notification is output to, for example, the control circuit and remote controller of the indoor unit 1b.

[0258] The control circuit 35A then acquires the intensities of the first light and the second light from the light detection device 32A (S178). The control circuit 35A determines whether the intensity of the first light exceeds a second determination value and whether the intensity of the second light exceeds a fifth determination value (S179). The fifth determination value is equal to or less than the fourth threshold. In this embodiment, the fifth determination value is equal to the lower detection limit of the second light.

[0259] In step S179, if the intensity of the first light exceeds the second determination value or the intensity of the second light exceeds the fifth determination value (S179: YES), the process proceeds to step S152 in FIG.

[0260] In step S179, if the intensity of the first light does not exceed the second determination value and the intensity of the second light does not exceed the fifth determination value (S179: NO), the control circuit 35A determines whether a fifth monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced (S180). The fifth monitoring time is shorter than the third monitoring time. The fifth monitoring time is, for example, approximately 10,000 times the period corresponding to the reference frequency of the inverter circuit 312, which is approximately 2 seconds to 10 seconds.

[0261] In step S180, if the fifth monitoring time has elapsed since the reduction in the set value of the amplitude of the AC output power (S180: YES), the control circuit 35A cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S181), and proceeds to step S150 in FIG. 19 .

[0262] In step S180, if the fifth monitoring time has not elapsed since the set value of the amplitude of the AC output power was decreased (S180: NO), the process returns to step S178.

[0263] In steps S178 to S180, if the intensity of the first light exceeds the second judgment value or the intensity of the second light exceeds the fifth judgment value before the fifth monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced, the process proceeds to step S152 in FIG. 19 , and if the intensity of the first light does not exceed the second judgment value or the intensity of the second light does not exceed the fourth judgment value before the fifth monitoring time has elapsed since the set value of the amplitude of the AC output power was reduced, the process proceeds to step S181.

[0264] In step S174, if the intensity of the second light does not exceed the fifth threshold (step S175: NO), the process proceeds to step S150 in FIG.

[0265] In step S165 of Fig. 22, if the intensity of the first light does not exceed the third threshold (step S165: NO), referring to Fig. 25, the control circuit 35A acquires the intensity of the second light from the light detection device 32A (S182). Steps S183 to S189 of Fig. 25 are the same as steps S131 to S137 of Fig. 16, respectively. In step S187 of Fig. 25, if the intensity of the second light exceeds the third determination value, the process proceeds to step S152 of Fig. 19. After step S189 of Fig. 25, the process proceeds to step S150 of Fig. 19.

[0266] If the intensity of the second light does not exceed the fourth threshold in step S183 (step S183: NO), referring to FIG. 26, the control circuit 35A determines whether the intensity of the second light exceeds a fifth threshold that is smaller than the fourth threshold (step S190). Steps S191 to S196 in FIG. 26 are the same as steps S143 to S148 in FIG. 18, respectively. If the intensity of the second light exceeds the fourth determination value in step S194 in FIG. 26, the process proceeds to step S152 in FIG. 19. After step S196 in FIG. 26, the process proceeds to step S150 in FIG. 19.

[0267] In step S190, if the intensity of the second light does not exceed the fifth threshold (step S190: NO), the process proceeds to step S150 in FIG.

[0268] [1.4.2 Effects, etc.] The control device 3A described above controls the compressor 4 of the refrigeration cycle circuit 2 through which the working medium 20 circulates. The working medium 20 contains an ethylene-based fluoroolefin as a refrigerant component. The compressor 4 includes a sealed container 40 that forms a flow path for the working medium 20, a compression mechanism 41 located within the sealed container 40 and compressing the working medium 20, and an electric motor 42 located within the sealed container 40 and operating the compression mechanism 41. The control device 3A includes a drive circuit 31 that drives the electric motor 42, a light detection device 32A that detects light within the sealed container 40 and outputs the light intensity, and a control circuit 35A that stops or limits the operation of the drive circuit 31 when the light intensity exceeds a light threshold. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0269] In the control device 3A, the light includes first light having a wavelength greater than 600 nm and less than or equal to 2000 nm, and second light having a wavelength greater than or equal to 200 nm and less than or equal to 600 nm. The control circuit 35A stops or limits the operation of the drive circuit 31 in different ways when the intensity of the first light exceeds a first light threshold and when the intensity of the second light exceeds a second light threshold. This configuration makes it possible to appropriately select whether to stop or limit the operation of the drive circuit 31, thereby extending the period during which the compressor 4 can continue to operate.

[0270] In the control device 3A, the thresholds for the first light include a first threshold, a second threshold lower than the first threshold, and a third threshold lower than the second threshold. The thresholds for the second light include a fourth threshold and a fifth threshold lower than the fourth threshold. The control circuit 35A stops operation of the drive circuit 31 when the intensity of the first light exceeds the first threshold. The control circuit 35A stops operation of the drive circuit 31 when the intensity of the first light exceeds the second threshold and the intensity of the second light exceeds the fifth threshold. The control circuit 35A stops operation of the drive circuit 31 when the intensity of the first light exceeds the third threshold and the intensity of the second light exceeds the fourth threshold. The control circuit 35A restricts operation of the drive circuit 31 when the intensity of the first light exceeds the third threshold and the intensity of the second light exceeds the fifth threshold. The control circuit 35A restricts operation of the drive circuit 31 when the intensity of the first light is equal to or lower than the third threshold and the intensity of the second light exceeds the fifth threshold. This configuration appropriately selects whether to stop or limit the operation of the drive circuit 31, thereby making it possible to extend the period during which the compressor 4 can continue to be driven.

[0271] [1.5 Fifth Embodiment] [1.5.1 Configuration] In a refrigeration cycle (refrigeration cycle circuit), slight discharge may occur in the compressor. Such discharge may generate soot in the working medium. Furthermore, depending on the type of working medium, discharge in the compressor may generate hydrogen fluoride. An increase in insoluble components such as soot or hydrogen fluoride may be a cause of an abnormality in the refrigeration cycle circuit.

[0272] The present embodiment provides a refrigeration cycle device, a light detection circuit, a control device, a control method, and a program that enable early detection of an abnormality in a refrigeration cycle circuit.

[0273] 27 is a block diagram of a refrigeration cycle apparatus 1B according to this embodiment. The refrigeration cycle apparatus 1B constitutes, for example, an air conditioner capable of cooling operation and heating operation. The refrigeration cycle apparatus 1B includes a refrigeration cycle circuit 2B and a control device 3B.

[0274] The refrigeration cycle circuit 2B includes a compressor 4, a first heat exchanger 5, an expansion valve 6, a second heat exchanger 7, a four-way valve 8, an accumulator 9, and a bubble removal mechanism 21.

[0275] Accumulator 9 is provided to prevent liquid compression in the compression chambers of compression mechanism 41. Accumulator 9 is located on the suction pipe 401 side of compressor 4. More specifically, accumulator 9 is located between suction pipe 401 of compressor 4 and four-way valve 8. Accumulator 9 separates working medium 20 into gaseous working medium 20 and liquid working medium 20, and introduces only the gaseous working medium 20 from suction pipe 401 into the inside of sealed container 40.

[0276] The bubble removal mechanism 21 is provided to remove or break down bubbles that may be contained in the working medium 20. Examples of a structure for removing or breaking down bubbles include a mesh structure, but there is no particular limitation, and any conventionally known structure can be used. In this embodiment, the bubble removal mechanism 21 is located between the compressor 4 and the accumulator 9.

[0277] The control device 3B controls the refrigeration cycle circuit 2B. In particular, the control device 3B controls the compressor 4 and the expansion valve 6 of the refrigeration cycle circuit 2B. Fig. 28 is a schematic diagram of the compressor 4 and the control device 3B. Fig. 29 is a schematic diagram of the inside of the compressor 4.

[0278] The control device 3B includes a drive circuit 31, a light detection circuit 32B, a first protection device 33, a second protection device 34, and a control circuit 35B.

[0279] The optical detection circuit 32B is an optical detection circuit for the refrigeration cycle circuit 2B through which the working medium 20 circulates. The optical detection circuit 32B is provided to detect abnormalities in the refrigeration cycle circuit 2B by utilizing changes in the transmittance of the working medium 20. If the working medium 20 is relatively unstable, for example, the generation of radicals may cause a disproportionation reaction of compounds contained in the working medium 20, resulting in the working medium 20 being converted into other compounds. The disproportionation reaction of the working medium 20 is thought to be caused by heat and radicals. For example, the disproportionation reaction of the working medium 20 is thought to occur when radicals are generated under high temperature and high pressure. The radicals may be generated, for example, by a discharge phenomenon that may occur when some abnormality occurs in the compressor 4 or the drive circuit 31. If a discharge phenomenon occurs, relatively stable compounds are generated from the working medium 20, which circulate within the refrigeration cycle circuit 2B together with the working medium 20 as insoluble components. For example, if the working medium contains an ethylene-based fluoroolefin, soot or hydrogen fluoride (HF) may be generated as insoluble components. Such unwanted components are examples of products generated from the working medium 20 by disproportionation reactions. When discharge phenomena occur repeatedly, the amount of insoluble components such as soot increases. Such an increase in insoluble components may cause an abnormality in the refrigeration cycle circuit 2B. The inventors have found that an increase in such insoluble components reduces the transmittance of the working medium 20. In other words, by focusing on the transmittance of the working medium 20, the increase in insoluble components can be quantitatively evaluated, thereby enabling earlier detection of an abnormality in the refrigeration cycle circuit 2B.

[0280] The light detection circuit 32B enables evaluation of changes in the transmittance of the working medium based on changes in the intensity of light. As shown in Fig. 29, the light detection circuit 32B includes a light source device 321B and a light detection device 322B.

[0281] The light source device 321B emits light L32B into the refrigeration cycle circuit 2B. In this embodiment, the light L32B is directional light (for example, laser light or parallel light obtained by parallelizing a light-emitting diode (LED) using a lens or a double slit). The color of the light L32B is not particularly limited, and may be white or red with a wavelength of 650 nm to 690 nm. The light detection device 322B receives the light L32B and outputs the intensity of the received light L32B. In this embodiment, the light detection device 322B outputs a light detection signal indicating the intensity of the light L32B to the control circuit 35B.

[0282] The arrangement of the light source device 321B and the photodetector device 322B will be further described. In this embodiment, the light source device 321B emits light to the working medium 20, and the photodetector device 322B receives light L32B via the working medium 20. There are no particular limitations on the location in the refrigeration cycle circuit 2B from which the light source device 321B emits light to the working medium 20. In this embodiment, the light source device 321B emits light L32B to the working medium 20 in the compressor 4 of the refrigeration cycle circuit 2B. Because the above-mentioned discharge phenomenon may occur in the motor 42 of the compressor 4, it is considered that a decrease in transmittance due to insoluble components such as soot in the working medium 20 in the compressor 4 is easily detected.

[0283] In this embodiment, the light detection circuit 32B is located within the sealed container 40 of the compressor 4. The light source device 321B emits light L32B to the working medium 20 in the region between the electric motor 42 and the suction pipe 401. In FIG. 29 , the light source device 321B is disposed below the electric motor 42, but this is not a limitation. The light source device 321B may be disposed above the electric motor 42. The working medium 20 may contain bubbles. Bubbles in the working medium 20 scatter the light L32B, causing a decrease in the transmittance of the working medium 20 and adversely affecting evaluation using transmittance. Here, it is considered that the amount of bubbles is small in the region between the electric motor 42 and the suction pipe 401. Therefore, it is possible to suppress a decrease in accuracy due to bubbles.

[0284] FIG. 30 is a schematic diagram of the light sensing circuit 32B.

[0285] The light source device 321B includes a first light source 3211-1 and a second light source 3211-2. The first light source 3211-1 and the second light source 3211-2 are, for example, LEDs that emit white light.

[0286] The photodetector device 322B includes a first photodetector 3220-1 and a second photodetector 3220-2. The first photodetector 3220-1 is disposed to receive light L32B-1 emitted from the first light source 3211-1. The second photodetector 3220-2 is disposed to receive light L32B-2 emitted from the second light source 3211-2. In this embodiment, the first photodetector 3220-1 is disposed opposite the first light source 3211-1, and the second photodetector 3220-2 is disposed opposite the second light source 3211-2.

[0287] In this embodiment, the light detection signal output from the light detection device 322B to the control circuit 35B may include one or more light detection signals indicating the intensities of the lights L32B-1 and L32B-2.

[0288] The first photodetector 3220-1 includes a photodetector element 3221-1 and an optical system 3222-1. The second photodetector 3220-2 includes a photodetector element 3221-2 and an optical system 3222-2. The photodetector elements 3221-1 and 3221-2 include, for example, photodiodes. The optical systems 3222-1 and 3222-2 include, for example, lenses (condenser lenses).

[0289] In this embodiment, the optical systems 3222-1 and 3222-2 are optically designed so that the light receiving area D32-1 of the first photodetector 3220-1 is larger (ie, has a larger aperture ratio) than the light receiving area D32-2 of the second photodetector 3220-2.

[0290] 30, bubbles B in the refrigeration cycle circuit 2B can scatter light L32B-1 and L32B-2 from the light source device 321B. Here, the light-receiving area D32-1 of the first photodetector 3220-1 is larger than the light-receiving area D32-2 of the second photodetector 3220-2, and therefore the first photodetector 3220-1 is less susceptible to the effect of scattering by bubbles B than the second photodetector 3220-2, and the second photodetector 3220-2 is more susceptible to the effect of scattering by bubbles B than the first photodetector 3220-1. When the set intensity of light L32B-1 emitted from the first light source 3211-1 and the set intensity of light L32B-2 emitted from the second light source 3211-2 are the same, if there is no bubble B, the intensity of light L32-1 received by the first photodetector 3220-1 and the intensity of light L32B-2 received by the second photodetector 3220-2 will be substantially equal. On the other hand, if there is a bubble B, the intensity of light L32B-2 received by the second photodetector 3220-2 will be smaller than the intensity of light L32B-1 received by the first photodetector 3220-1. Therefore, this difference in the intensities of light L32B-1 and L32B-2 received by the first and second photodetectors 3220-1 and 3220-2 can be used as an indicator of scattering by the bubble B, i.e., the presence of the bubble B.

[0291] The control circuit 35B can be realized, for example, by a computer system including at least one processor (microprocessor) and one or more memories. The computer system may also include one or more A / D converters. For example, the one or more A / D converters are used to convert the light detection signal from the light detection circuit 32B from analog to digital format. The control circuit 35B, like the control circuit 35, controls the drive circuit 31, the first protection device 33, and the second protection device 34.

[0292] The control circuit 35B determines whether an abnormality has occurred in the refrigeration cycle circuit 2B based on the light detection signal from the light detection circuit 32B, and if it determines that an abnormality has occurred, it stops or restricts the operation of the refrigeration cycle circuit 2B.

[0293] The control circuit 35B causes the light source device 321B to emit light L32B into the refrigeration cycle circuit 2B, and acquires the intensity of the light L32B that has passed through the refrigeration cycle circuit 2B using the photodetector 322B. The control circuit 35B adjusts the rotation speed of the compressor 4 to reduce the influence of bubbles B that may be contained in the working medium 20. Specifically, during at least a portion of the period in which the photodetector 322B receives the light L32B, the control circuit 35B reduces the rotation speed of the compressor 4 of the refrigeration cycle circuit 2B below the maximum value of the rotation speed during a period in which the photodetector 322B does not receive the light L32B. The period in which the photodetector 322B does not receive the light L32B corresponds to a period in which the refrigeration cycle circuit 2B is in normal operation. Preferably, the control circuit 35B sets the rotation speed of the compressor 4 of the refrigeration cycle circuit 2B to less than half of the maximum rotation speed during the period when the optical detection device 322B does not receive the light L32B, throughout the entire period when the optical detection device 322B receives the light L32B. By reducing the rotation speed of the compressor 4, it is expected that the amount of bubbles B generated will be reduced. This makes it possible to reduce the influence of bubbles B that may be contained in the working medium 20, and improve the accuracy of detecting abnormalities in the refrigeration cycle circuit 2B.

[0294] In this embodiment, the control circuit 35B stops or limits the operation of the refrigeration cycle circuit 2B when the intensity of the light L32B indicated by the light detection signal from the light detection circuit 32B satisfies a predetermined condition.

[0295] The predetermined condition may be that the index value of the intensity of light L32B is equal to or less than a threshold value. This predetermined condition corresponds to the amount of products generated from the working fluid 20 by the disproportionation reaction being equal to or greater than a predetermined amount. The threshold value may be determined by evaluating, through testing or simulation, the transmittance of the working fluid 20 at which an abnormality is likely to occur in the refrigeration cycle circuit 2B. The threshold value may be, for example, equal to or less than 95% of the index value of the intensity of light L32B in the initial rated operating state. In other words, the predetermined condition may be that the index value of the intensity of light L32B is equal to or less than 95% of the index value of the intensity of light L32B in the initial rated operating state. The index value of the light intensity is a value derived directly or indirectly from the light intensity, and may be the light intensity itself or the light transmittance. The index value of the light intensity is also an index value of the amount of products generated from the working fluid 20 by the disproportionation reaction. The index value of the intensity of the light L32B in the initial rated operation state may be set based on a representative value of the index values ​​of the light intensity detected by the light detection device 322B when the refrigeration cycle circuit 2B is operated for the first time, for example. Here, the representative value may be selected from the average value, the mode value, the maximum value, the minimum value, the median value, etc.

[0296] The predetermined condition may be that the ratio of the index value of the intensity of light L32B at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of light L32B at a first time point is equal to or less than a predetermined ratio. This predetermined condition corresponds to the increase in the amount of products generated from the working fluid 20 by the disproportionation reaction within a predetermined period of time being equal to or greater than a predetermined amount. The predetermined ratio may be determined by evaluation through testing or simulation based on the transmittance of the working fluid 20 at which an abnormality is likely to occur in the refrigeration cycle circuit 2B. For example, the predetermined ratio may be equal to or less than 95%. That is, the predetermined condition may be that the ratio of the index value of the intensity of light L32B at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of light L32B at the first time point is equal to or less than 95%. The first time point may be, for example, the start of operation of the refrigeration cycle circuit 2B, and the second time point may be any time during operation of the refrigeration cycle circuit 2B.

[0297] In the control device 3B described above, the light detection circuit 32B receives light L32B from inside the sealed container 40 of the compressor 4 of the refrigeration cycle circuit 2B and outputs the intensity of the received light L32B as a second state. When the control circuit 35B detects a sign of a disproportionation reaction based on the second state related to the working fluid 20, it stops or limits the operation of the refrigeration cycle circuit 2B. Here, the control circuit 35B determines an index value for the amount of products generated from the working fluid 20 by the disproportionation reaction based on the intensity of light L32B. The sign of a disproportionation reaction is when the amount of products or the increase in the amount of products within a predetermined period of time is equal to or greater than a predetermined amount.

[0298] As described above, the light detection circuit 32B includes the first light detector 3220-1 and the second light detector 3220-2, and the control circuit 35B can use the difference in intensity between the light beams L32B-1 and L32B-2 received by the first and second light detectors 3220-1 and 3220-2 as an index of the amount of bubbles B. When calculating the index value of the intensity of light L32B, the control circuit 35B can make a correction based on the amount of bubbles B. In other words, a correction can be made to remove the amount of reduction in the intensity of light L32B due to bubbles B. To correct for the effects of bubbles B, a relationship between the difference in intensity between the light beams L32B-1 and L32B-2 received by the first and second light detectors 3220-1 and 3220-2 and the amount of bubbles B can be determined through experiments, simulations, or the like, and a table may be prepared in advance that associates this intensity difference with the amount of correction for the intensity of light L32B. The control circuit 35B determines a correction amount by referring to a table based on the difference in intensity between the light L32B-1 and L32B-2 received by the first and second photodetectors 3220-1 and 3220-2, and calculates an index value for the intensity of the light L32B taking the correction amount into account from the intensities of the light L32B-1 and L32B-2 received by the first and second photodetectors 3220-1 and 3220-2. Furthermore, the control circuit 35B calculates the time average of the intensities of the light L32B-1 and L32-2 received by the first and second photodetectors 3220-1 and 3220-2, for example, the average of the intensities of the incident light (light L32B-1 and L32B-2) with a time constant of about 0.1 s to 1 s, and then calculates the difference between them, thereby reducing measurement errors due to bubbles flowing together with the working medium 20 and improving the accuracy of abnormality detection.

[0299] As described above, the refrigeration cycle apparatus 1B includes the bubble removal mechanism 21. In the present embodiment, the bubble removal mechanism 21 is located between the compressor 4 and the accumulator 9, and is disposed upstream of the portion (inside the compressor 4) in the refrigeration cycle circuit 2B from which the light source device 321B emits the light L32B. This makes it possible to reduce the influence of bubbles B that may be contained in the working medium 20, and improve the accuracy of detecting an abnormality in the refrigeration cycle circuit 2B.

[0300] Stopping or limiting the operation of the refrigeration cycle circuit 2B may include stopping the operation of the drive circuit 31, increasing the rotation speed of the condenser fan, decreasing the rotation speed of the evaporator fan, increasing the opening of the expansion valve, (if the refrigeration cycle device 1B has multiple indoor units 1b) opening the expansion valve of at least one of the indoor units 1b that are not operating, and (in the case of heating operation) switching to cooling operation using the four-way valve 8 and opening the expansion valve 6.

[0301] The control circuit 35B stops or restricts the operation of the refrigeration cycle circuit 2B in different ways depending on the number of times the intensity of the light L32B satisfies a predetermined condition. In particular, the control circuit 35B executes processing to stop or restrict the operation of the refrigeration cycle circuit 2B to a higher degree as the number of times the intensity of the light L32B satisfies the predetermined condition increases. This enables earlier detection of an abnormality in the refrigeration cycle circuit 2B. As a result, the safety of use of the working medium 20 can be improved.

[0302] The control circuit 35B stops or limits the operation of the refrigeration cycle circuit 2B in different ways depending on the time difference between the first time when the intensity of the light L32B first satisfies the predetermined condition and the second time when the intensity of the light L32B next satisfies the predetermined condition. In particular, the control circuit 35B executes processing to operate or stop the refrigeration cycle circuit 2B to a higher degree as the time difference is shorter. This enables the control device 3 to detect an abnormality in the refrigeration cycle circuit 2B earlier, thereby improving the safety of use of the working medium 20.

[0303] The process for stopping or limiting the operation of the refrigeration cycle circuit 2B includes, for example, first to third processes. The first process is a process for stopping the output of AC output power and resuming the output of AC output power after a standby time has elapsed. The second process is a process for stopping the output of AC output power and operating the refrigeration cycle circuit 2B after a standby time has elapsed, with a set value for the amplitude of the AC output power being reduced. The third process is a process for stopping the output of AC output power and stopping the input of input power. Among the first to third processes, the degree to which the operation of the refrigeration cycle circuit 2B is stopped or limited increases in the order of the third process, the second process, and the first process. Even in the first or second process, the longer the standby time, the greater the degree to which the operation of the refrigeration cycle circuit 2B is stopped or limited.

[0304] Next, an example of the operation of the control circuit 35B of the control device 3B will be briefly described with reference to Figures 31 to 36. Each of Figures 31 to 36 is a part of a flowchart of the operation of the control circuit 35B of the control device 3B, and Figures 31 to 36 are combined to complete one flowchart.

[0305] See Figure 31. The control circuit 35B outputs AC output power to the motor 42 based on the input power of the power supply 10 via the drive circuit 31, thereby driving the compressor 4. The control circuit 35B sets the number of abnormalities to 0 (S210). The number of abnormalities indicates the number of times the intensity of the light L32B satisfies a predetermined condition. The number of abnormalities is an indicator of the likelihood of an abnormality occurring in the refrigeration cycle circuit 2B.

[0306] The control circuit 35B acquires a light detection signal from the light detection circuit 32B (S211). The control circuit 35B determines whether the intensity of the light L32B indicated by the light detection signal satisfies a predetermined condition (S212).

[0307] If the intensity of the light L32B does not satisfy the predetermined condition (S212: NO), the process returns to step S211. In steps S211 and S212, the control circuit 35B periodically determines whether the intensity of the light L32B satisfies the predetermined condition.

[0308] In step S212, if the intensity of the light L32B satisfies the predetermined condition (S212: YES), the control circuit 35B adds 1 to the number of abnormalities (S213), and determines whether the number of abnormalities is 1 or less (S214).

[0309] If the number of abnormalities is 1 or less in step S214 (YES in step S214), the control circuit 35B sets the first protection device 33 to the OFF state to stop the output of AC output power (S215). The control circuit 35B then determines whether a first standby time has elapsed since the output of AC output power was stopped (S216). The first standby time is, for example, 1 second. If the first standby time has elapsed (YES in step S216), the control circuit 35B sets the first protection device 33 to the ON state to resume the output of AC output power (S217), thereby restarting the operation of the compressor 4 and the refrigeration cycle circuit 2B (S218). Then, the process returns to step S211.

[0310] In this way, the control circuit 35B stops the output of AC output power when the intensity of the light L32B satisfies a predetermined condition, and resumes the output of AC output power when the first standby time has elapsed since the output of AC output power was stopped.

[0311] If the number of abnormalities is not equal to or less than 1 in step S214 (S214: NO), referring to FIG. 32, the control circuit 35B determines whether the time difference between the first time when the intensity of light L32B first satisfied the predetermined condition and the second time when the intensity of light L32B next satisfied the predetermined condition is within a first predetermined time (step S219). The shortness of this time difference is an indicator of the likelihood of an abnormality occurring in the refrigeration cycle circuit 2B. The first predetermined time is, for example, approximately 20 to 100 ms.

[0312] If the time difference is within the first predetermined time in step S219 (step S219: YES), the control circuit 35B sets the first protection device 33 to the OFF state to stop the output of AC output power (S220). The control circuit 35B sets the second protection device 34 to the OFF state to stop the input of input power (S221). The control circuit 35B outputs a first abnormality notification (S222). The first abnormality notification indicates that there is a very high possibility that an abnormality will occur in the refrigeration cycle circuit 2B in the refrigeration cycle apparatus 1B. Thereafter, the control circuit 35B stops operation of the compressor 4 to stop operation of the refrigeration cycle circuit 2B (S223).

[0313] In this way, if the detected voltage becomes less than the second voltage (S219: YES) before a predetermined time (first predetermined time) has elapsed since the output of AC output power was resumed after the first waiting time had elapsed (S217), the control circuit 35B stops the output of AC output power (S220) and stops the input of input power (S221).

[0314] If the time difference is not within the first predetermined time in step S219 (step S219: NO), referring to Fig. 33, the control circuit 35B determines whether the time difference is within a second predetermined time that is longer than the first predetermined time (step S224). The second predetermined time is, for example, about 200 ms to 1 s.

[0315] If the time difference is within the second predetermined time in step S224 (step S224: YES), the control circuit 35B sets the first protection device 33 to the OFF state to stop the output of AC output power (S225). The control circuit 35B changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power decreases from E to E / 2 (S226). The control circuit 35B outputs a second abnormality notification (S227). The second abnormality notification indicates that there is a high possibility that an abnormality will occur in the refrigeration cycle circuit 2 of the refrigeration cycle apparatus 1.

[0316] The control circuit 35B determines whether a fourth standby time has elapsed since the output of AC output power was stopped (S228). The fourth standby time is longer than the first standby time. The fourth standby time is, for example, 60 seconds. When the fourth standby time has elapsed (S228: YES), as shown in FIG. 34, the control circuit 35B sets the first protection device 33 to the ON state to resume the output of AC output power (S229), thereby resuming operation of the compressor 4 (S230). In this case, the set value of the amplitude of the AC output power remains lowered from E to E / 2.

[0317] In this way, if the intensity of light L32B satisfies the predetermined condition before the predetermined time (second predetermined time) has elapsed since the output of AC output power was resumed after the first standby time (S217), the control circuit 35B stops the output of AC output power (S225) and reduces the set value of the amplitude of the AC output power (S226).If a fourth standby time longer than the first standby time has elapsed since the output of AC output power was stopped, the control circuit 35B resumes the output of AC output power while keeping the set value of the amplitude of the AC output power reduced (S229).

[0318] Thereafter, the control circuit 35B acquires a light detection signal from the light detection circuit 32B (S231), and determines whether the intensity of the light L32B satisfies a predetermined condition (S232).

[0319] In step S232, if the intensity of the light L32B satisfies the predetermined condition (S232: YES), the process proceeds to step S220 in FIG.

[0320] In step S232, if the intensity of the light L32B does not satisfy the predetermined condition (S232: NO), the control circuit 35B determines whether the second monitoring time has elapsed since the operation of the refrigeration cycle circuit 2B was restarted (S233).

[0321] In step S233, if the second monitoring time has elapsed since the operation of the refrigeration cycle circuit 2B was restarted (S233: YES), the control circuit 35B cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S234), and proceeds to step S211 in FIG. 31 .

[0322] In step S233, if the second monitoring time has not elapsed since the operation of the refrigeration cycle circuit 2B was restarted (S233: NO), the process returns to step S231.

[0323] In steps S231 to S233, if the intensity of light L32B satisfies a predetermined condition between the restart of operation of the refrigeration cycle circuit 2B and the elapse of the second monitoring time, the process proceeds to step S220 in FIG. 33, and if the intensity of light L32B does not satisfy the predetermined condition between the restart of operation of the refrigeration cycle circuit 2B and the elapse of the second monitoring time, the process proceeds to step S234.

[0324] In this way, if the intensity of light L32B does not satisfy the predetermined condition during the second monitoring time from when the output of AC output power is resumed after the fourth waiting time has elapsed (S229) (YES at S233), the control circuit 35B cancels the reduction of the set value of the amplitude of the AC output power (S234). If the intensity of light L32B satisfies the predetermined condition before the second monitoring time has elapsed from when the output of AC output power is resumed after the fourth waiting time has elapsed (S229) (YES at S232), the control circuit 35B stops the output of AC output power (S220) and stops the input of input power (S221).

[0325] 33, if the time difference is not within the second predetermined time in step S224 (step S224: NO), referring to FIG. 35, the control circuit 35B determines whether the time difference is within a third predetermined time that is longer than the second predetermined time (step S235). The third predetermined time is, for example, about 2 seconds to 10 seconds.

[0326] In step S235, if the time difference is not within the third predetermined time (step S235: NO), the process returns to step S210, and the control circuit 35B sets the number of abnormalities to 0 (see FIG. 31). In other words, if a sufficient amount of time has passed since the abnormality was detected, the possibility of an abnormality occurring in the refrigeration cycle circuit 2B is considered low, and therefore the number of abnormalities is reset to 0.

[0327] In step S235, if the time difference is within the third predetermined time (step S235: YES), the control circuit 35B determines whether the number of abnormalities is 2 or less (S236).

[0328] If the number of abnormalities is two or less in step S236 (S236: YES), the control circuit 35B sets the first protection device 33 to the OFF state and stops the output of AC output power (S237). The control circuit 35B outputs a third abnormality notification (S238). The third abnormality notification indicates that an abnormality may occur in the refrigeration cycle circuit 2B of the refrigeration cycle apparatus 1B. The control circuit 35B determines whether a second waiting time has elapsed since the output of AC output power was stopped (S239). The second waiting time is longer than the first waiting time. The second waiting time is, for example, 10 seconds. If the second waiting time has elapsed (S239: YES), the control circuit 35B sets the first protection device 33 to the ON state and resumes the output of AC output power (S240), thereby restarting the operation of the compressor 4 and the refrigeration cycle circuit 2B (S241). Then, the process returns to step S211.

[0329] In this way, the control circuit 35B stops the output of the AC output power if the intensity of the light L32B satisfies the predetermined condition before the predetermined time (third predetermined time) has elapsed since the output of the AC output power was resumed after the first standby time had elapsed (S17). The control circuit 35B resumes the output of the AC output power when the second standby time, which is longer than the first standby time, has elapsed since the output of the AC output power was stopped (S240).

[0330] In step S236, if the number of abnormalities is not two or less (S236: NO), that is, if the number of abnormalities is three or more, the control circuit 35B sets the first protection device 33 to the OFF state and stops the output of AC output power (S242). The control circuit 35B changes the switching control of the semiconductor switching elements of the drive circuit 31 so that the set value of the amplitude of the AC output power decreases from E to E / 2 (S243). The control circuit 35B outputs a second abnormality notification (S244).

[0331] The control circuit 35B determines whether a third standby time has elapsed since the output of the AC output power was stopped (S245). The third standby time is longer than the second standby time. The third standby time is, for example, 60 seconds. When the third standby time has elapsed (S245: YES), as shown in FIG. 36, the control circuit 35B sets the first protection device 33 to the ON state to resume the output of the AC output power (S246), thereby restarting the operation of the compressor 4 and the refrigeration cycle circuit 2B (S247). In this case, the set value of the amplitude of the AC output power remains lowered from E to E / 2.

[0332] In this way, if the intensity of light L32B satisfies the predetermined condition before the predetermined time (third predetermined time) has elapsed since the output of AC output power was resumed after the second standby time elapsed (S240), the control circuit 35B stops the output of AC output power (S242) and reduces the set value of the amplitude of the AC output power (S243).If the third standby time, which is longer than the second standby time, has elapsed since the output of AC output power was stopped, the control circuit 35B resumes the output of AC output power while keeping the set value of the amplitude of the AC output power reduced (S247).

[0333] Thereafter, the control circuit 35B acquires a light detection signal from the light detection circuit 32B (S248).The control circuit 35B determines whether the intensity of the light L32B satisfies a predetermined condition (S249).

[0334] In step S249, if the intensity of the light L32B satisfies the predetermined condition (S249: YES), the process proceeds to step S220 in FIG.

[0335] If the intensity of the light L32B does not satisfy the predetermined condition in step S249 (S249: NO), the control circuit 35B determines whether the first monitoring time has elapsed since the operation of the refrigeration cycle circuit 2B was restarted (S250). The first monitoring time may be the same as or different from the second monitoring time in step S233.

[0336] In step S250, if the first monitoring time has elapsed since the operation of the refrigeration cycle circuit 2B was restarted (S250: YES), the control circuit 35B cancels the reduction in the set value of the amplitude of the AC output power, returns the set value of the amplitude of the AC output power to E (S251), and proceeds to step S211 in FIG. 31 .

[0337] In step S250, if the first monitoring time has not elapsed since the operation of the refrigeration cycle circuit 2B was restarted (S250: NO), the process returns to step S248.

[0338] In steps S248 to S250, if the intensity of light L32B satisfies a predetermined condition between the restart of operation of the refrigeration cycle circuit 2B and the elapse of the first monitoring time, the process proceeds to step S220 in FIG. 33, and if the intensity of light L32B does not satisfy the predetermined condition between the restart of operation of the compressor 4 and the elapse of the first monitoring time, the process proceeds to step S251.

[0339] In this way, if the intensity of light L32B does not satisfy the predetermined condition during the first monitoring time from when the output of AC output power is resumed after the third standby time has elapsed (S247) (YES at S250), the control circuit 35B cancels the reduction of the set value of the amplitude of the AC output power (S251). If the intensity of light L32B satisfies the predetermined condition before the first monitoring time has elapsed from when the output of AC output power is resumed after the third standby time has elapsed (S247) (YES at S249), the control circuit 35B stops the output of AC output power (S220) and stops the input of input power (S221).

[0340] [1.5.2 Effects, etc.] The control device 3B described above is a control device that controls a refrigeration cycle circuit 2B in which a working medium 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and includes a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2B, and a control circuit 35B that stops or limits the operation of the refrigeration cycle circuit 2B when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2B or a second state related to the working medium 20. This configuration can improve the accuracy of detection of a disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0341] The control device 3B includes a light detection device 322B that receives light L32B through the interior of the refrigeration cycle circuit 2B and outputs the intensity of the received light L32B as a second state. The control device 3B determines an index value for the amount of products produced from the working fluid 20 by the disproportionation reaction based on the intensity of light L32B. A sign of the disproportionation reaction is when the amount of products or the increase in the amount of products within a predetermined period of time is equal to or greater than a predetermined amount. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0342] It can be said that the control device 3B described above executes the following control method. The control method stops or restricts the operation of the refrigeration cycle circuit 2B when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2B and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0343] The control method includes determining an indicator value of the amount of product produced by the disproportionation reaction from the working fluid 20 based on the second state. The indication of the disproportionation reaction is that the amount of product or an increase in the amount of product within a predetermined period of time is equal to or greater than a predetermined amount. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0344] The control method executed by the control device 3B can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3B, which controls the refrigeration cycle circuit 2B through which the working fluid 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and causes the computer system to execute a process to stop or limit the operation of the refrigeration cycle circuit 2B when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2B and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0345] The refrigeration cycle apparatus 1B described above includes a refrigeration cycle circuit 2B in which the working medium 20 circulates, a light source device 321B that radiates light L32B into the refrigeration cycle circuit 2B, and a light detection device 322B that receives the light L32B and outputs the intensity of the received light L32B. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B.

[0346] In the refrigeration cycle apparatus 1B, the light source device 321B emits light L32B to the working medium 20, and the light detection device 322B receives the light L32B via the working medium 20. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B.

[0347] In the refrigeration cycle apparatus 1B, the light source device 321B radiates light to the working medium 20 in the compressor 4 of the refrigeration cycle circuit 2B. This configuration makes it possible to improve the accuracy of detecting an abnormality in the refrigeration cycle circuit 2B.

[0348] In the refrigeration cycle apparatus 1B, the compressor 4 includes a suction pipe 401 for the working medium 20, a discharge pipe 402 for the working medium 20, and an electric motor 42 located between the suction pipe 401 and the discharge pipe 402, and the light source device 321B emits light L32B to the working medium 20 in the region between the electric motor 42 and the suction pipe 401. This configuration enables improvement in the accuracy of detecting an abnormality in the refrigeration cycle circuit 2B.

[0349] In the refrigeration cycle apparatus 1B, the photodetector 322B includes a first photodetector 3220-1 and a second photodetector 3220-2, and the light-receiving area D32-1 of the first photodetector 3220-1 is larger than the light-receiving area D32-2 of the second photodetector 3220-2. This configuration reduces the influence of bubbles B that may be contained in the working medium 20, and improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2B.

[0350] The refrigeration cycle apparatus 1B further includes a bubble removal mechanism 21 that is disposed in the refrigeration cycle circuit 2B upstream of a portion where the light source device 321B emits the light L32B and that removes or breaks down bubbles B in the working medium 20. This configuration reduces the influence of bubbles B that may be contained in the working medium 20 and improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2B.

[0351] The refrigeration cycle apparatus 1B further includes a control circuit 35B that controls the operation of the refrigeration cycle circuit 2B. The control circuit 35B stops or limits the operation of the refrigeration cycle circuit 2B when the intensity of the light L32B output from the photodetector 322B satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0352] In the refrigeration cycle apparatus 1B, the control circuit 35B reduces the rotation speed of the compressor 4 of the refrigeration cycle circuit 2B during at least a portion of the period during which the photodetector 322B receives the light L32B to a value lower than the maximum rotation speed during the period during which the photodetector 322B does not receive the light L32B. This configuration reduces the influence of bubbles B that may be contained in the working medium 20, and improves the accuracy of detecting an abnormality in the refrigeration cycle circuit 2B.

[0353] In the refrigeration cycle device 1B, the predetermined condition is that the index value of the intensity of the light L32B is 95% or less of the index value of the intensity of the light L32B in the initial rated operating state. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B.

[0354] In the refrigeration cycle device 1B, the predetermined condition is that the ratio of the index value of the intensity of light L32B at a second time point a predetermined time after the first time point to the index value of the intensity of light L32B at a first time point is 95% or less. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B.

[0355] The above-described optical detection circuit 32B is an optical detection circuit for the refrigeration cycle circuit 2B in which the working medium 20 circulates, and includes a light source device 321 that radiates light L32B into the refrigeration cycle circuit 2B, and an optical detection device 322B that receives the light L32B and outputs the intensity of the received light L32B. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B.

[0356] The control device 3B described above includes the photodetector circuit 32B and a control circuit 35B that controls the operation of the refrigeration cycle circuit 2B. The control circuit 35B stops or limits the operation of the refrigeration cycle circuit 2B when the intensity of the light L32B output from the photodetector 322B of the photodetector circuit 32B satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0357] The control device 3B described above can be said to execute the following control method. The control method is executed by the control device 3B, which controls the refrigeration cycle circuit 2B through which the working medium 20 circulates. The control method receives light L32B emitted into the refrigeration cycle circuit 2B using the photodetector 322B, outputs the intensity of the received light L32B, and stops or limits the operation of the refrigeration cycle circuit 2B when the intensity of the light L32B output from the photodetector 322B satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0358] In the control method, the photodetector 322B includes a first photodetector 3220-1 and a second photodetector 3220-2, and the light-receiving area D32-1 of the first photodetector 3220-1 is larger than the light-receiving area D32-2 of the second photodetector 3220-2. The control method corrects an index value of the intensity of the light output from the photodetector 322B based on the difference between the intensity of the light L32B-1 output from the first photodetector 3220-1 and the intensity of the light L32B-2 output from the second photodetector 3220-2, and stops or limits the operation of the refrigeration cycle circuit 2B when the corrected index value of the light intensity satisfies a predetermined condition. This configuration reduces the influence of bubbles B that may be contained in the working medium 20 and improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2B.

[0359] The control method executed by the control device 3B can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3B, which controls the refrigeration cycle circuit 2B through which the working medium 20 circulates. The program receives light L32B emitted into the refrigeration cycle circuit 2B by the photodetector 322B, outputs the intensity of the received light L32B, and stops or limits the operation of the refrigeration cycle circuit 2B when the intensity of the light L32B output from the photodetector 322B satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2B. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0360] In the program, the photodetector 322B includes a first photodetector 3220-1 and a second photodetector 3220-2, and the light-receiving area D32-1 of the first photodetector 3220-1 is larger than the light-receiving area D32-2 of the second photodetector 3220-2. The program corrects an index value of the intensity of the light output from the photodetector 322B based on the difference between the intensity of the light L32B-1 output from the first photodetector 3220-1 and the intensity of the light L32B-2 output from the second photodetector 3220-2. When the corrected index value of the light intensity satisfies a predetermined condition, the program stops or limits the operation of the refrigeration cycle circuit 2B. This configuration reduces the influence of bubbles B that may be contained in the working medium 20 and improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2B.

[0361] [1.6 Sixth Embodiment] [1.6.1 Configuration] In a refrigeration cycle (refrigeration cycle circuit), slight discharge may occur in the compressor. Such discharge may generate soot in the working medium. Furthermore, depending on the type of working medium, discharge in the compressor may generate hydrogen fluoride. An increase in insoluble components such as soot or hydrogen fluoride may be a cause of an abnormality in the refrigeration cycle circuit.

[0362] The present embodiment provides a refrigeration cycle device, a light detection method, a control method, and a program that enable early detection of an abnormality in a refrigeration cycle circuit.

[0363] 37 is a block diagram of a refrigeration cycle apparatus 1C according to embodiment 6. The refrigeration cycle apparatus 1C constitutes, for example, an air conditioner capable of cooling operation and heating operation. The refrigeration cycle apparatus 1C includes a refrigeration cycle circuit 2C and a control device 3C.

[0364] The refrigeration cycle circuit 2C includes a compressor 4, a first heat exchanger 5, an expansion valve 6, a second heat exchanger 7, a four-way valve 8, and an accumulator 9. The refrigeration cycle circuit 2C further includes a phosphor 11C (see FIG. 38 ).

[0365] The control device 3C controls the refrigeration cycle circuit 2C. In particular, the control device 3C controls the compressor 4 and the expansion valve 6 of the refrigeration cycle circuit 2C. Fig. 38 is a schematic diagram of the compressor 4 and the control device 3C.

[0366] The control device 3C includes a drive circuit 31, a light detection circuit 32C, a first protection device 33, a second protection device 34, and a control circuit 35C.

[0367] The optical detection circuit 32C is used to detect abnormalities in the refrigeration cycle circuit 2C through which the working medium 20 circulates. In particular, the optical detection circuit 32C is provided to detect abnormalities in the refrigeration cycle circuit 2C using a fluorescent dye. When the working medium 20 has relatively low stability, for example, the generation of radicals may cause a disproportionation reaction of a compound contained in the working medium 20, resulting in the compound being converted into another compound. The disproportionation reaction of the working medium 20 is thought to be caused by heat and radicals. For example, the disproportionation reaction of the working medium 20 is thought to occur when radicals are generated under high temperature and high pressure. Radicals may be generated, for example, by a discharge phenomenon that may occur when some abnormality occurs in the compressor 4 or the drive circuit 31. When a discharge phenomenon occurs, products resulting from a chemical reaction of the working medium 20 may circulate within the refrigeration cycle circuit 2C along with the working medium 20. For example, when the working medium contains an ethylene-based fluoroolefin, an example of a product resulting from a chemical reaction of the working medium 20 (hereinafter also referred to as product (A)) is hydrogen fluoride (HF). Such product (A) is an example of a product generated from the working fluid 20 by a disproportionation reaction. Repeated discharge phenomena increase the amount of product (A). An increase in product (A) can also cause an abnormality in the refrigeration cycle circuit 2C. The inventors discovered that a fluorescent dye can be used to quantitatively evaluate product (A). That is, if the fluorescent dye has the property of changing at least one of the fluorescence wavelength or quantum yield upon reaction with product (A), an increase in product (A) can be observed as a change in the intensity of light at a wavelength corresponding to the fluorescence wavelength of the fluorescent dye. By focusing on the intensity of light at a wavelength corresponding to the fluorescence wavelength of the fluorescent dye, product (A) can be quantitatively evaluated, which allows for the determination of cumulative minor damage to the refrigeration cycle circuit 2C and enables earlier detection of an abnormality in the refrigeration cycle circuit 2C.

[0368] 39 is a schematic diagram of the light detection circuit 32C. In this embodiment, the light detection circuit 32C makes it possible to evaluate an abnormality in the refrigeration cycle circuit 2C by using a phosphor 11C.

[0369] The phosphor 11C contains a fluorescent dye and is arranged in the refrigeration cycle circuit 2C so as to be able to come into contact with the working medium 20. In this embodiment, the phosphor 11C is refrigeration oil in which the fluorescent dye is dissolved. That is, the phosphor 11C is formed by dissolving the fluorescent dye in the refrigeration oil of the compressor 4. The phosphor 11C circulates through the refrigeration cycle circuit 2C together with the working medium 20. This increases the possibility that the fluorescent dye of the phosphor 11C will come into contact with and react with the product (A).

[0370] The fluorescent dye has the property of changing at least one of the fluorescence wavelength or quantum yield upon reacting with the product (A) produced by the chemical reaction of the working medium 20. Therefore, depending on the type of fluorescent dye, the reaction between the fluorescent dye and the product (A) can cause an increase or decrease in the amount of light of the fluorescent wavelength.

[0371] Examples of fluorescent dyes are shown below: The following examples of fluorescent dyes are particularly preferred when the product (A) is a substance that generates fluoride ions (for example, hydrogen fluoride).

[0372] The fluorescent dye may be a triarylfluorosilane compound. The triarylfluorosilane compound is, for example, SiFR １ R ２ R ３ (See formula (1)). １ , R ２ and R ３ are either anthracene or a derivative thereof, or R １ and R ２ is anthracene or its derivative and R ３ is benzene or its derivatives.

[0373]

[0374] The fluorescent dye may be a compound having a structure in which a donor group and an acceptor group are bonded. The donor group has donor properties in an excited state. The donor group is a chromophore. The acceptor group has high acceptor properties in a free state and low acceptor properties when bonded to product (A) or an ion derived from product (A). The acceptor group is a receptor.

[0375] The acceptor group may be selected from the group consisting of a compound having a structure in which two or more amino groups are bonded via one or two methylene groups (hereinafter also referred to as compound (B)), a compound having a structure in which two or more pyrrole groups or indole groups are bonded via two methylene groups (hereinafter also referred to as compound (C)), benzamide, bis(methylidene)hydrazine, and calixarene.

[0376] Examples of the compound (B) include urea and its derivatives, thiourea and its derivatives, and polyamine macrocycles.

[0377] Examples of compound (C) include 1,2-ethanediyl-bis(pyrrole) and 1,2-ethanediyl-bis(indol).

[0378] The donor group may be selected from the group consisting of anthracene, naphthalimide, pyrene, bodipy, fluorescein, rhodamine, resorufin, coumarin, and cyanine.

[0379] For example, some of the above-mentioned fluorescent dyes change their fluorescence wavelength upon reaction with product (A). As an example, in the case of a triarylfluorosilane compound, the fluorescence wavelength at an excitation wavelength of 366 nm changes from 416 nm to 396 nm. Therefore, the presence of product (A) can be detected by a decrease in the intensity of light with a fluorescence wavelength of 416 nm or an increase in the intensity of light with a fluorescence wavelength of 396 nm.

[0380] As shown in FIG. 39, the light detection circuit 32C includes a light source device 321C and a light detection device 322C.

[0381] The light source device 321C emits excitation light Le having a wavelength corresponding to the excitation wavelength of the fluorescent dye into the refrigeration cycle circuit 2C. In this embodiment, the excitation light Le is directional light (e.g., laser light). The wavelength range of the excitation light Le needs to include the excitation wavelength of the fluorescent dye. However, it is preferable that the wavelength range of the excitation light Le does not include the fluorescence wavelength of the fluorescent dye. The light source device 321C is, for example, a laser diode.

[0382] The photodetector 322C receives light Lf having a wavelength corresponding to the fluorescence wavelength of the fluorescent dye and outputs the intensity of the received light Lf. In this embodiment, the photodetector 322C outputs a photodetection signal indicating the intensity of light Lf to the control circuit 35C. The wavelength range to which the photodetector 322C is sensitive only needs to include the fluorescence wavelength of the fluorescent dye. However, if the fluorescence wavelength of the fluorescent dye changes, it is preferable that the wavelength range to which the photodetector 322C is sensitive includes only either the fluorescence wavelength before the change or the fluorescence wavelength after the change. It is also preferable that the wavelength range to which the photodetector 322C is sensitive does not include the excitation wavelength of the fluorescent dye. The photodetector 322C includes, for example, a photodiode and an optical system (e.g., a lens, etc.).

[0383] Next, the arrangement of the light source device 321C and the light detection device 322C will be described.

[0384] The light source device 321C emits excitation light Le to a portion between the discharge pipe 402 of the compressor 4 of the refrigeration cycle circuit 2C and the condenser (the first heat exchanger 5 during cooling operation and the second heat exchanger 7 during heating operation). In particular, in this embodiment, the light source device 321C emits excitation light Le to a portion between the discharge pipe 402 of the compressor 4 and the four-way valve 8. The light source device 321C emits excitation light Le to a portion closer to the discharge pipe 402 of the compressor 4 than the four-way valve 8. This increases the likelihood that the excitation light Le will hit the fluorescent element. This configuration enables improved accuracy in detecting abnormalities in the refrigeration cycle circuit 2C.

[0385] The photodetector 322C receives light Lf from a portion between the discharge pipe 402 of the compressor 4 of the refrigeration cycle circuit 2C and the condenser (the first heat exchanger 5 during cooling operation, and the second heat exchanger 7 during heating operation). In particular, in this embodiment, the photodetector 322C receives light Lf from a portion between the discharge pipe 402 of the compressor 4 and the four-way valve 8. The photodetector 322C receives light Lf from a portion closer to the discharge pipe 402 of the compressor 4 than the four-way valve 8. This can improve the intensity of the light Lf received by the photodetector 322C. This configuration makes it possible to improve the accuracy of detecting abnormalities in the refrigeration cycle circuit 2C.

[0386] The control circuit 35C can be realized, for example, by a computer system including at least one processor (microprocessor) and one or more memories. The computer system may also include one or more A / D converters. For example, the one or more A / D converters are used to convert the light detection signal from the light detection circuit 32C from analog to digital format. The control circuit 35C, like the control circuit 35, controls the drive circuit 31, the first protection device 33, and the second protection device 34.

[0387] The control circuit 35C determines whether an abnormality has occurred in the refrigeration cycle circuit 2C based on the light detection signal from the light detection circuit 32C, and if it determines that an abnormality has occurred, it stops or restricts the operation of the refrigeration cycle circuit 2C.

[0388] In this embodiment, the control circuit 35C stops or limits the operation of the refrigeration cycle circuit 2C when the intensity of the light Lf indicated by the light detection signal from the light detection circuit 32C satisfies a predetermined condition.

[0389] The predetermined conditions are set according to the type of fluorescent dye.

[0390] Consider a case where the reaction between the fluorescent dye and the product (A) causes an increase in the amount of light Lf at the fluorescent wavelength of the fluorescent dye. For example, if the reaction changes the fluorescent wavelength of the fluorescent dye, the wavelength of light Lf detected by the photodetector 322C may correspond to the changed fluorescent wavelength. In this case, the predetermined condition may be that the ratio of the index value of the intensity of light Lf at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of light Lf at a first time point is equal to or greater than a predetermined ratio. The index value of the intensity of light Lf is a value derived directly or indirectly from the intensity of light Lf and may be the intensity of light Lf itself or a representative value of the intensity of light Lf over a certain period of time. The representative value may be selected from the average, mode, maximum, minimum, median, etc. The index value of the intensity of light Lf also indicates the amount of product generated from the working fluid 20 by the disproportionation reaction. The predetermined ratio may be determined by evaluation through testing or simulation based on the amount of product (A) at which an abnormality is likely to occur in the refrigeration cycle circuit 2C. For example, the predetermined ratio may be 110%. That is, the predetermined condition may be that the ratio of the index value of the intensity of light Lf at a second time point a predetermined time after the first time point to the index value of the intensity of light Lf at a first time point is 110% or more. The first time point may be, for example, the start of operation of the refrigeration cycle circuit 2C, and the second time point may be any time point during operation of the refrigeration cycle circuit 2C. In this case, the predetermined condition corresponds to the amount of products generated from the working fluid 20 by the disproportionation reaction becoming equal to or greater than a predetermined amount. The first time point may be any time point during operation of the refrigeration cycle circuit 2C, and the second time point may be a predetermined period after the first time point. In this case, the predetermined condition corresponds to the increase in the amount of products generated from the working fluid 20 by the disproportionation reaction within a predetermined period becoming equal to or greater than a predetermined amount.

[0391] Consider a case where the reaction between the fluorescent dye and the product (A) causes a decrease in the amount of light Lf at the fluorescent wavelength of the fluorescent dye. For example, if the fluorescent wavelength of the fluorescent dye changes due to the reaction, the wavelength of light Lf detected by the photodetector 322C may correspond to the fluorescent wavelength before the change. In this case, the predetermined condition may be that the ratio of the index value of the intensity of light Lf at a second time point, a predetermined time after the first time point, to the index value of the intensity of light Lf at a first time point is equal to or less than a predetermined percentage. The predetermined percentage may be determined by evaluation through testing or simulation based on the amount of product (A) at which an abnormality is likely to occur in the refrigeration cycle circuit 2C. For example, the predetermined percentage may be 90%. That is, the predetermined condition may be that the ratio of the index value of the intensity of light Lf at a second time point, a predetermined time after the first time point, to the index value of the intensity of light Lf at the first time point is equal to or less than 90%. The first time point may be, for example, the start of operation of the refrigeration cycle circuit 2C, and the second time point may be any time during operation of the refrigeration cycle circuit 2C.

[0392] In the control device 3C described above, the light detection circuit 32C receives light Lf from inside the refrigeration cycle circuit 2C and outputs the intensity of the received light Lf as a second state. When the control circuit 35C detects a sign of a disproportionation reaction based on the second state of the working medium 20, it stops or limits the operation of the refrigeration cycle circuit 2C. Here, the control circuit 35C determines an index value for the amount of products generated from the working medium 20 by the disproportionation reaction based on the intensity of light Lf. The sign of a disproportionation reaction is when the amount of products or the increase in the amount of products within a predetermined period of time is equal to or greater than a predetermined amount.

[0393] In this embodiment, a fluorescent dye is used to detect a change in light Lf from the fluorescent dye that may occur when a discharge phenomenon occurs. Therefore, when no discharge phenomenon occurs, no change occurs in light Lf. This reduces the possibility of erroneously determining that an abnormality has occurred in the refrigeration cycle circuit 2C when no discharge phenomenon occurs.

[0394] Stopping or limiting the operation of the refrigeration cycle circuit 2C may include stopping the operation of the drive circuit 31, increasing the rotation speed of the condenser fan, decreasing the rotation speed of the evaporator fan, increasing the opening of the expansion valve, (if the refrigeration cycle device 1C has multiple indoor units 1b) opening the expansion valve of at least one of the indoor units 1b that are not operating, and (in the case of heating operation) switching to cooling operation using the four-way valve 8 and opening the expansion valve 6.

[0395] The control circuit 35C stops or restricts the operation of the refrigeration cycle circuit 2C in different ways depending on the number of times the intensity of the light Lf satisfies a predetermined condition. In particular, the control circuit 35C executes processing to stop or restrict the operation of the refrigeration cycle circuit 2C to a higher degree as the number of times the intensity of the light Lf satisfies the predetermined condition increases. This enables earlier detection of an abnormality in the refrigeration cycle circuit 2C. As a result, the safety of use of the working medium 20 can be improved.

[0396] The control circuit 35C stops or limits the operation of the refrigeration cycle circuit 2C in different ways depending on the time difference between the first time when the intensity of the light Lf first satisfies the predetermined condition and the second time when the intensity of the light Lf next satisfies the predetermined condition. In particular, the shorter the time difference, the more the control circuit 35C executes processing to operate or stop the refrigeration cycle circuit 2C to a higher degree. This enables the control device 3C to detect an abnormality in the refrigeration cycle circuit 2C earlier, thereby improving the safety of use of the working medium 20.

[0397] The process for stopping or limiting the operation of the refrigeration cycle circuit 2C includes, for example, first to third processes. The first process is a process for stopping the output of AC output power and resuming the output of AC output power after a standby time has elapsed. The second process is a process for stopping the output of AC output power and operating the refrigeration cycle circuit 2C after a standby time has elapsed, with a set value for the amplitude of the AC output power being reduced. The third process is a process for stopping the output of AC output power and stopping the input of input power. Among the first to third processes, the degree to which the operation of the refrigeration cycle circuit 2C is stopped or limited increases in the order of the third process, the second process, and the first process. Even in the first or second process, the longer the standby time, the greater the degree to which the operation of the refrigeration cycle circuit 2C is stopped or limited.

[0398] The operation of the control circuit 35C may be similar to the operation of the control circuit 35B described with reference to Figures 31 to 36. More specifically, the operation of the control circuit 35C may be the operation of the control circuit 35B described with reference to Figures 31 to 36, in which the description regarding the light detection circuit 32B is replaced with the description regarding the light detection circuit 32C.

[0399] [1.6.2 Effects, etc.] The control device 3C described above is a control device that controls a refrigeration cycle circuit 2C in which a working fluid 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and includes a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2C, and a control circuit 35C that stops or limits the operation of the refrigeration cycle circuit 2C when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2C or a second state related to the working fluid 20. This configuration can improve the accuracy of detection of a disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0400] In the control device 3C, the refrigeration cycle circuit 2C includes a phosphor 11C containing a fluorescent dye. The control device 3C also includes a photodetector 322C that detects light Lf having a wavelength corresponding to the fluorescent wavelength of the fluorescent dye and outputs the intensity of the detected light Lf as a second state. The control circuit 35C determines an index value for the amount of products produced from the working fluid by the disproportionation reaction based on the intensity of light Lf output from the photodetector 322C. A sign of the disproportionation reaction is when the amount of products or the increase in the amount of products within a predetermined period of time exceeds a predetermined amount. This configuration improves the accuracy of detection of the disproportionation reaction of the working fluid 20 and enables improved suppression of the disproportionation reaction.

[0401] It can be said that the control device 3C described above executes the following control method. The control method stops or restricts the operation of the refrigeration cycle circuit 2C when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2C and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0402] The control method includes determining an indicator value of the amount of product produced by the disproportionation reaction from the working fluid 20 based on the second state. The indication of the disproportionation reaction is that the amount of product or an increase in the amount of product within a predetermined period of time is equal to or greater than a predetermined amount. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0403] The control method executed by the control device 3C can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3C that controls a refrigeration cycle circuit 2C through which a working fluid 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and causes the computer system to execute a process to stop or limit the operation of the refrigeration cycle circuit 2C when a sign of a disproportionation reaction is detected based on at least one of a first state related to a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2C and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of a disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0404] The refrigeration cycle apparatus 1C described above includes a refrigeration cycle circuit 2C through which the working medium 20 circulates, and a phosphor 11C arranged in the refrigeration cycle circuit 2C so as to be in contact with the working medium 20. The phosphor 11C contains a fluorescent dye that has the property of changing at least one of the fluorescence wavelength or quantum yield upon reacting with a product (A) produced by a chemical reaction of the working medium 20. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C.

[0405] In the refrigeration cycle apparatus 1C, the light source device 321C emits excitation light Le to a portion of the refrigeration cycle circuit 2C between the discharge pipe 402 of the compressor 4 and the condenser (the first heat exchanger 5 and the second heat exchanger 7). This configuration enables improved accuracy in detecting an abnormality in the refrigeration cycle circuit 2C.

[0406] In the refrigeration cycle device 1C, the fluorescent dye contains a triarylfluorosilane compound. This configuration enables improvement in the accuracy of detecting an abnormality in the refrigeration cycle circuit 2C.

[0407] In the refrigeration cycle device 1C, the fluorescent dye is a compound having a structure in which an acceptor group and a donor group are bonded together. The acceptor group is selected from the group consisting of a compound having two or more amino groups bonded together via one or two methylene groups, a compound having two or more pyrrole or indole groups bonded together via two methylene groups, benzamide, bismethylidine hydrazine, and calixarene. The donor group is selected from the group consisting of anthracene, naphthalimide, pyrene, bodipy, fluorescein, rhodamine, resorufin, coumarin, and cyanine. This configuration enables improved accuracy in detecting abnormalities in the refrigeration cycle circuit 2C.

[0408] In the refrigeration cycle apparatus 1C, the phosphor 11C is a refrigeration oil having a fluorescent dye dissolved therein. This configuration can increase the possibility that the fluorescent dye of the phosphor 11C will come into contact with and react with the product (A).

[0409] The refrigeration cycle apparatus 1C further includes a light source device 321C that radiates excitation light Le having a wavelength corresponding to the excitation wavelength of the fluorescent dye into the refrigeration cycle circuit 2C, and a light detection device 322C that detects light Lf having a wavelength corresponding to the fluorescence wavelength of the fluorescent dye and outputs the intensity of the detected light Lf. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C.

[0410] The refrigeration cycle apparatus 1C includes a control circuit 35C that controls the operation of the refrigeration cycle circuit 2C. When the intensity of the light Lf output from the photodetector 322C satisfies a predetermined condition, the control circuit 35C stops or limits the operation of the refrigeration cycle circuit 2C. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0411] In the refrigeration cycle apparatus 1C, the reaction between the fluorescent dye and the product (A) causes an increase in the amount of light of the fluorescent wavelength, and the predetermined condition is that the ratio of the index value of the intensity of light Lf at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of light Lf at a first time point is 110% or more. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C.

[0412] In the refrigeration cycle apparatus 1C, the reaction between the fluorescent dye and the product (A) causes a decrease in the amount of light of the fluorescent wavelength, and the predetermined condition is that the ratio of the index value of the intensity of light Lf at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of light Lf at a first time point is 90% or less. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C.

[0413] The refrigeration cycle apparatus 1C described above executes an optical detection method for a refrigeration cycle circuit 2C through which a working medium 20 circulates. This optical detection method irradiates excitation light Le having a wavelength corresponding to the excitation wavelength of a fluorescent dye to a phosphor 11C that contains a fluorescent dye and is arranged in the refrigeration cycle circuit 2C so as to be in contact with the working medium 20, detects light Lf having a wavelength corresponding to the fluorescence wavelength of the fluorescent dye, and outputs the intensity of the detected light. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C.

[0414] The control device 3C described above can be said to execute the following control method. The control method is executed by the control device 3C, which controls a refrigeration cycle circuit 2C through which the working medium 20 circulates and which contains a fluorescent material 11C containing a fluorescent dye. The control device 3C includes a photodetector 322. The control method detects light Lf having a wavelength corresponding to the fluorescent wavelength of the fluorescent dye, outputs the intensity of the detected light, and stops or limits operation of the refrigeration cycle circuit 2C when the intensity of the light Lf output from the photodetector 322C satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0415] The control method executed by the control device 3C can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3C, which controls a refrigeration cycle circuit 2C through which the working medium 20 circulates and which contains a fluorescent dye-containing phosphor 11C. The control device 3C includes a photodetector 322C. The program detects light Lf having a wavelength corresponding to the fluorescent wavelength of the fluorescent dye, outputs the intensity of the detected light, and stops or limits operation of the refrigeration cycle circuit 2C when the intensity of the light Lf output from the photodetector 322C satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2C. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0416] [1.7 Seventh embodiment] [1.7.1 Configuration] Fig. 40 is a schematic diagram of a compressor 4 and a control device 3D of a refrigeration cycle apparatus according to embodiment 7. The refrigeration cycle apparatus according to embodiment 7 includes a configuration similar to that of the refrigeration cycle apparatus 1C according to embodiment 6, and therefore Fig. 37 and reference numerals will be used for similar configurations as necessary.

[0417] The control device 3D includes a drive circuit 31, a light detection circuit 32D, a first protection device 33, a second protection device 34, and a control circuit 35.

[0418] 37 and 41 are schematic diagrams of the light detection circuit 32D. In this embodiment, the light detection circuit 32D enables evaluation of an abnormality in the refrigeration cycle circuit 2C by using the phosphor 11D.

[0419] The phosphor 11D contains a fluorescent dye and is arranged in the refrigeration cycle circuit 2C so as to be able to come into contact with the working medium 20. In this embodiment, the phosphor 11D is a support supporting the fluorescent dye. The support is, for example, a porous body. The porous body may be an inorganic or organic porous body. Examples of inorganic porous bodies include mesoporous silica. Examples of organic porous bodies include synthetic resin membranes or paper. Porous bodies can ensure a larger surface area, thereby increasing the likelihood that the fluorescent dye will come into contact with the working medium 20. The phosphor 11D is fixed at a predetermined location in the refrigeration cycle circuit 2C. In this embodiment, the phosphor 11D is arranged in the sealed container 40 of the compressor 4. For example, the phosphor 11D is located in the region between the electric motor 42 and the discharge pipe 402. In phosphor 11D, unlike phosphor 11C, the fluorescent dye is not dispersed throughout the refrigeration cycle circuit 2C but is located in a predetermined location, which reduces the possibility of contact with the working medium 20, but ensures that the excitation light Le can be applied reliably.

[0420] The light detection circuit 32D includes a light source device 321C and a light detection device 322C. The light source device 321C emits excitation light Le into the compressor 4 of the refrigeration cycle circuit 2C. This causes the excitation light Le to be emitted into the sealed container 40 of the compressor 4, and the excitation light Le strikes the phosphor 11D inside the sealed container 40 of the compressor 4. In this embodiment, the light source device 321C is disposed inside the sealed container 40 of the compressor 4. For example, the light source device 321C is located in the area between the motor 42 and the discharge pipe 402. This increases the likelihood that the excitation light Le strikes the fluorescent element. This configuration improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2C. The light detection device 322C receives light Lf from inside the compressor 4 of the refrigeration cycle circuit 2C. In this embodiment, the light detection device 322C is disposed inside the sealed container 40 of the compressor 4. For example, the light source device 321C is located in the region between the electric motor 42 and the discharge pipe 402. This can improve the intensity of the light Lf received by the light detection device 322. This configuration can improve the accuracy of detecting an abnormality in the refrigeration cycle circuit 2C.

[0421] [1.2.2 Effects, etc.] In the refrigeration cycle apparatus 1C described above, the light source device 321C emits excitation light Le into the compressor 4 of the refrigeration cycle circuit 2C. This configuration enables improvement in the accuracy of detecting an abnormality in the refrigeration cycle circuit 2C.

[0422] In the refrigeration cycle apparatus 1C, the phosphor 11D is a support that supports a fluorescent dye. This configuration ensures that the fluorescent dye is located in a predetermined location without being dispersed throughout the refrigeration cycle circuit 2C, allowing it to be reliably irradiated with the excitation light Le.

[0423] In the refrigeration cycle apparatus 1C, the support includes a porous body. This configuration can increase the possibility that the fluorescent dye will come into contact with the working medium 20.

[0424] [1.8 Eighth Embodiment] [1.8.1 Configuration] Fig. 42 is a block diagram of a refrigeration cycle apparatus 1E according to an eighth embodiment. The refrigeration cycle apparatus 1E constitutes, for example, an air conditioner capable of cooling operation and heating operation. The refrigeration cycle apparatus 1E includes a refrigeration cycle circuit 2E and a control device 3E.

[0425] The refrigeration cycle circuit 2E includes a compressor 4, a first heat exchanger 5, an expansion valve 6, a second heat exchanger 7, a four-way valve 8, and an accumulator 9. The refrigeration cycle circuit 2E further includes a light absorber 11E (see FIG. 43).

[0426] The control device 3E controls the refrigeration cycle circuit 2E. In particular, the control device 3E controls the compressor 4 and the expansion valve 6 of the refrigeration cycle circuit 2E. Fig. 43 is a schematic diagram of the compressor 4 and the control device 3E. The refrigeration cycle circuit 2E further includes a light absorber 11E.

[0427] The control device 3E includes a drive circuit 31, a light detection circuit 32E, a first protection device 33, a second protection device 34, and a control circuit 35E.

[0428] The optical detection circuit 32E is used to detect abnormalities in the refrigeration cycle circuit 2E through which the working medium 20 circulates. In particular, the optical detection circuit 32E is provided to detect abnormalities in the refrigeration cycle circuit 2E using a dye. If the working medium 20 has relatively low stability, for example, the generation of radicals may cause a disproportionation reaction of a compound contained in the working medium 20, resulting in the compound being converted into another compound. The disproportionation reaction of the working medium 20 is thought to be caused by heat and radicals. For example, the disproportionation reaction of the working medium 20 is thought to occur when radicals are generated under high temperature and high pressure. The radicals may be generated, for example, by a discharge phenomenon that may occur when some abnormality occurs in the compressor 4 or the drive circuit 31. If a discharge phenomenon occurs, products generated by a chemical reaction of the working medium 20 may circulate within the refrigeration cycle circuit 2E together with the working medium 20. For example, if the working medium contains an ethylene-based fluoroolefin, products generated by a chemical reaction of the working medium 20 (hereinafter also referred to as product (D)) include tetrafluoroethylene (C ). ２ F ４ ) or hydrogen fluoride (HF). Such product (D) is an example of a product generated from the working medium 20 by a disproportionation reaction. When discharge phenomena are repeated, the amount of product (D) increases. An increase in product (D) may cause an abnormality in the refrigeration cycle circuit 2E. The inventors have discovered that a dye can be used to quantitatively evaluate product (D). In other words, if a dye has the property of changing the absorption maximum wavelength upon reaction with product (D), an increase in product (D) can be observed as a change in the intensity of light in a wavelength band including the absorption wavelength of the dye.

[0429] Figure 44 is a graph showing an example of the wavelength change of the absorbance of the dye. In Figure 44, the horizontal axis is wavelength and the vertical axis is absorbance. F1 is a graph showing the wavelength change of the absorbance of the dye before the reaction with product (D), and F2 is a graph showing the wavelength change of the absorbance of the dye after the reaction with product (D). In Figure 43, the maximum absorption wavelength λ of the dye changes due to the reaction with product (D). １ The absorbance at １ From A ２Depending on the dye, F1 may be a graph showing the wavelength change of the absorbance of the dye after the reaction with product (D), and F2 may be a graph showing the wavelength change of the absorbance of the dye before the reaction with product (D). This is because the maximum absorption wavelength λ of the dye decreases due to the reaction with product (D). １ The absorbance at １ From A ２ This means that the

[0430] The maximum absorption wavelength λ of the dye １ and the maximum absorption wavelength of the dye after the reaction with product (D) is desirably large enough to enable sufficient distinction between the waveform of the wavelength change of the absorbance of the dye and the waveform of the wavelength change of the absorbance of the dye after the reaction with product (D).

[0431] In this way, by focusing on the intensity of light in a wavelength band that includes the absorption wavelength of the dye, it is possible to quantitatively evaluate the product (D), which makes it possible to determine cumulative minor damage to the refrigeration cycle circuit 2E and enable earlier detection of abnormalities in the refrigeration cycle circuit 2E.

[0432] 45 is a schematic diagram of the light detection circuit 32E. In this embodiment, the light detection circuit 32E enables evaluation of an abnormality in the refrigeration cycle circuit 2E by using a light absorption body 11E.

[0433] The light absorber 11E contains a dye and is disposed in the refrigeration cycle circuit 2E so as to be able to come into contact with the working medium 20. In this embodiment, the light absorber 11E is refrigeration oil in which a dye is dissolved. That is, the light absorber 11E is formed by dissolving a dye in the refrigeration oil of the compressor 4. The light absorber 11E circulates through the refrigeration cycle circuit 2E together with the working medium 20. This increases the possibility that the dye in the light absorber 11E will come into contact with and react with the product (D).

[0434] The dye has the property of changing the maximum absorption wavelength upon reaction with the product (D) produced by the chemical reaction of the working medium 20. Therefore, depending on the type of dye, the reaction between the dye and the product (D) can cause an increase or decrease in the amount of light at the absorption wavelength.

[0435] A first example of the dye is shown below. This first example of the dye is preferred when the product (D) is tetrafluoroethylene. The first example of the dye may include a nickel complex. The nickel complex may react with tetrafluoroethylene and change its absorbance. Therefore, the presence of tetrafluoroethylene as the product (D) can be detected by a change in the intensity of light at the wavelength at which the absorbance changes. Examples of nickel complexes include bistriphenylphosphine nickel(0) (see formula (2)), bis(ortho-diphenylphosphanylphenyl)ether nickel(0) (see formula (3)), 2,2'-bis(ortho-diphenylphosphino)trans-stilbene nickel(0) (see formula (4)), 2,2'-bis(diphenylphosphino)biphenyl nickel(0) (see formula (5)), 2,2'-bis(diphenylphosphino)diphenylmethane nickel(0) (see formula (6)), and 2,2'-bis(diphenylphosphino)diphenylpropane nickel (see formula (7)).

[0436]

[0437]

[0438]

[0439]

[0440]

[0441]

[0442] A second example of the dye is shown below. The second example of the dye is preferred when the product (D) is hydrogen fluoride. The second example of the dye may include a boron compound having an aromatic substituent. A boron compound having an aromatic substituent may react with hydrogen fluoride and change its absorbance. Therefore, the presence of hydrogen fluoride as the product (D) can be detected by a change in the intensity of light at a wavelength at which the absorbance changes. An example of a boron compound having an aromatic substituent is diarylnaphthylborane represented by formula (8). Note that R １ and R ２are each selected from the group consisting of a naphthyl group represented by formula (9) or a mesityl group represented by formula (10).

[0443]

[0444]

[0445]

[0446] As shown in FIG. 45, the light detection circuit 32E includes a light source device 321E and a light detection device 322E.

[0447] The light source device 321E emits light beams L32E-1 and L32E-2 in a wavelength band that includes the absorption wavelength of the dye into the refrigeration cycle circuit 2E. In this embodiment, the light source device 321E includes a first light source 3213-1 and a second light source 3213-2. The first light source 3213-1 and the second light source 3213-2 emit light beams L32E-1 and L32E-2 into the refrigeration cycle circuit 2E. The wavelength bands of the light beams L32E-1 and L32E-2 are different from each other. This means that the light beams L32E-1 and L32E-2 correspond to different absorption wavelengths of the dye. In this way, the light source device 321E emits multiple light beams L32E-1 and L32E-2 in different wavelength bands. For example, the light beams L32E-1 and L32E-2 are directional light beams (e.g., laser beams). The first light source 3213-1 and the second light source 3213-2 are, for example, laser diodes.

[0448] The optical detection device 322E receives the light beams L32E-1 and L32E-2 from the light source device 321E and outputs the intensities of the received light beams L32E-1 and L32E-2. In the present embodiment, the optical detection device 322E outputs an optical detection signal indicating the intensities of the received light beams L32E-1 and L32E-2 to the control circuit 35E. In the present embodiment, the optical detection signal output from the optical detection device 322E to the control circuit 35E may include one or more optical detection signals indicating the intensities of the light beams L32E-1 and L32E-2. In this way, by using the intensities of the multiple light beams L32E-1 and L32E-2 in different wavelength bands, the influence of the colors of substances other than the pigment of the light absorber 11E, for example, the influence of a change in the hue of refrigerating machine oil, can be reduced.

[0449] The light detection device 322E includes a first light detector 3223-1 and a second light detector 3223-2. The first light detector 3223-1 is disposed to receive light L32E-1 emitted from the first light source 3213-1. The second light detector 3223-2 is disposed to receive light L32E-2 emitted from the second light source 3213-2. In this embodiment, the first light detector 3223-1 is disposed facing the first light source 3213-1, and the second light detector 3223-2 is disposed facing the second light source 3213-2. Each of the first light detector 3223-1 and the second light detector 3223-2 includes a light detection element and an optical system. The light detection element includes, for example, a photodiode. The optical system includes, for example, a lens (condenser lens).

[0450] Next, the arrangement of the light source device 321E and the light detection device 322E will be described.

[0451] The light source device 321E emits light beams L32E-1 and L32E-2 toward a portion between the discharge pipe 402 of the compressor 4 of the refrigeration cycle circuit 2E and the condenser (the first heat exchanger 5 during cooling operation and the second heat exchanger 7 during heating operation). In particular, in this embodiment, the light source device 321E emits light beams L32E-1 and L32E-2 toward a portion 22 between the discharge pipe 402 of the compressor 4 and the four-way valve 8. The light source device 321E emits light beams L32E-1 and L32E-2 toward a portion closer to the discharge pipe 402 of the compressor 4 than the four-way valve 8. This increases the likelihood that the light beams L32E-1 and L32E-2 will hit the dye. This configuration improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2E.

[0452] The optical detection device 322E receives light beams L32E-1 and L32E-2 from a portion 22 between the discharge pipe 402 of the compressor 4 of the refrigeration cycle circuit 2E and the condenser (the first heat exchanger 5 during cooling operation and the second heat exchanger 7 during heating operation). In particular, in this embodiment, the optical detection device 322E receives light beams L32E-1 and L32E-2 from a portion between the discharge pipe 402 of the compressor 4 and the four-way valve 8. The optical detection device 322E receives light beams L32E-1 and L32E-2 from a portion closer to the discharge pipe 402 of the compressor 4 than the four-way valve 8. This improves the intensity of the light beams L32E-1 and L32E-2 received by the optical detection device 322E. This configuration improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2E.

[0453] The control circuit 35E can be realized, for example, by a computer system including at least one processor (microprocessor) and one or more memories. The computer system may also include one or more A / D converters. For example, the one or more A / D converters are used to convert the light detection signal from the light detection circuit 32E from analog to digital format. The control circuit 35E controls the drive circuit 31, the first protection device 33, and the second protection device 34 in the same way as the control circuit 35.

[0454] The control circuit 35E determines whether an abnormality has occurred in the refrigeration cycle circuit 2E based on the light detection signal from the light detection circuit 32E, and if it determines that an abnormality has occurred, it stops or restricts the operation of the refrigeration cycle circuit 2E.

[0455] In this embodiment, the control circuit 35E stops or limits the operation of the refrigeration cycle circuit 2E when the intensity of the light L32E indicated by the light detection signal from the light detection circuit 32E satisfies a predetermined condition. In this embodiment, the light detection signal from the light detection circuit 32E includes the intensities of multiple light beams L32E-1, L32E-2 of different wavelength bands. The control circuit 35E stops or limits the operation of the refrigeration cycle circuit 2E when at least one of the intensities of the multiple light beams L32E-1, L32E-2 satisfies a predetermined condition.

[0456] The predetermined conditions are set depending on the type of dye.

[0457] Consider a case where the wavelength band of light L32E-1 and L32E-2 from the light source device 321E includes an absorption wavelength at which the absorbance of the dye decreases due to a reaction between the dye and product (D). For example, this is the case where the absorbance at the dye's maximum absorption wavelength decreases due to the reaction. In this case, the predetermined condition may be that the ratio of the index value of the intensity of light L32E at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of light L32E at a first time point is equal to or greater than a predetermined ratio. The index values ​​of the intensity of light L32E-1 and L32E-2 are values ​​derived directly or indirectly from the intensities of light L32E-1 and L32E-2, and may be the intensities of light L32E-1 and L32E-2 themselves, or may be a representative value of the intensities of light L32E-1 and L32E-2 over a certain period of time. The representative value may be selected from the average, mode, maximum, minimum, median, etc. The index values ​​of the intensities of the light beams L32E-1 and L32E-2 are also index values ​​of the amount of product generated from the working fluid 20 by the disproportionation reaction. The predetermined ratio may be determined by evaluation through testing or simulation based on the amount of product (D) that is likely to cause an abnormality in the refrigeration cycle circuit 2E. For example, the predetermined ratio may be 110%. In other words, the predetermined condition may be that the ratio of the index values ​​of the intensities of the light beams L32E-1 and L32E-2 at a second time point, a predetermined time after the first time point, to the index values ​​of the intensities of the light beams L32E-1 and L32E-2 at a first time point is 110% or greater. The first time point may be, for example, the start of operation of the refrigeration cycle circuit 2E or any time point during operation. The predetermined time is not particularly limited, but is preferably set so that a change in the absorbance of the dye due to the generation of product (D) can be observed. When the first time point is the start of operation of the refrigeration cycle circuit 2, the predetermined condition corresponds to the amount of product generated from the working fluid 20 by the disproportionation reaction being equal to or greater than a predetermined amount. When the first time point is any time point during operation, the predetermined condition corresponds to the increase in the amount of the product produced from the working medium 20 by the disproportionation reaction within a predetermined period of time being equal to or greater than a predetermined amount.

[0458] Consider a case where the wavelength band of light L32E-1 and L32E-2 from the light source device 321E includes an absorption wavelength at which the absorbance of the dye increases due to a reaction between the dye and the product (D). For example, this is the case where the reaction increases the absorbance at the dye's absorption maximum wavelength. In this case, the predetermined condition may be that the ratio of the index value of the intensity of light L32E at a second time point, a predetermined time after the first time point, to the index value of the intensity of light L32E at a first time point is equal to or less than a predetermined percentage. The predetermined percentage may be determined by evaluation through testing or simulation based on the amount of product (D) at which an abnormality is likely to occur in the refrigeration cycle circuit 2E. For example, the predetermined percentage may be 90%. In other words, the predetermined condition may be that the ratio of the index value of the intensity of light L32E at a second time point, a predetermined time after the first time point, to the index value of the intensity of light L32E at the first time point is equal to or less than 90%.

[0459] In the control device 3E described above, the light detection circuit 32E receives light L32E from inside the refrigeration cycle circuit 2E and outputs the intensity of the received light L32E as a second state. When the control circuit 35E detects a sign of a disproportionation reaction based on the second state related to the working medium 20, it stops or limits the operation of the refrigeration cycle circuit 2E. Here, the control circuit 35E determines an index value for the amount of products generated from the working medium 20 by the disproportionation reaction based on the intensity of the light L32E. The sign of a disproportionation reaction is when the amount of products or the increase in the amount of products within a predetermined period of time is equal to or greater than a predetermined amount.

[0460] In this embodiment, a dye is used to detect changes in the absorbance of the dye that may occur when a discharge phenomenon occurs. Therefore, by using the absorbance that can change with respect to the absorption wavelength as a probe, it is possible to evaluate the accumulation of products caused by a discharge phenomenon while reducing the influence of luminescence suppressing substances such as metals.

[0461] Stopping or limiting the operation of the refrigeration cycle circuit 2E may include stopping the operation of the drive circuit 31, increasing the rotation speed of the condenser fan, decreasing the rotation speed of the evaporator fan, increasing the opening of the expansion valve, (if the refrigeration cycle device 1E has multiple indoor units 1b) opening the expansion valve of at least one of the indoor units 1b that are not operating, and (in the case of heating operation) switching to cooling operation using the four-way valve 8 and opening the expansion valve 6.

[0462] The control circuit 35E stops or restricts the operation of the refrigeration cycle circuit 2E in different ways depending on the number of times the intensity of the light L32E satisfies a predetermined condition. In particular, the control circuit 35E executes processing to stop or restrict the operation of the refrigeration cycle circuit 2E to a higher degree as the number of times the intensity of the light L32E satisfies the predetermined condition increases. This enables earlier detection of an abnormality in the refrigeration cycle circuit 2E. As a result, the safety of use of the working medium 20 can be improved.

[0463] The control circuit 35E stops or limits the operation of the refrigeration cycle circuit 2E in different ways depending on the time difference between the first time when the intensity of the light L32E first satisfies the predetermined condition and the second time when the intensity of the light L32E next satisfies the predetermined condition. In particular, the control circuit 35E executes processing that operates or stops the refrigeration cycle circuit 2E to a higher degree as the time difference becomes shorter. This enables the control device 3E to detect an abnormality in the refrigeration cycle circuit 2E earlier. This improves the safety of use of the working medium 20.

[0464] The process for stopping or limiting the operation of the refrigeration cycle circuit 2E includes, for example, first to third processes. The first process is a process for stopping the output of AC output power and resuming the output of AC output power after a standby time has elapsed. The second process is a process for stopping the output of AC output power and operating the refrigeration cycle circuit 2E by reducing the set value of the amplitude of the AC output power after a standby time has elapsed. The third process is a process for stopping the output of AC output power and stopping the input of input power. Among the first to third processes, the degree to which the operation of the refrigeration cycle circuit 2E is stopped or limited increases in the order of the third process, the second process, and the first process. Even in the first or second process, the longer the standby time, the higher the degree to which the operation of the refrigeration cycle circuit 2E is stopped or limited.

[0465] The operation of the control circuit 35E may be similar to the operation of the control circuit 35B described with reference to Figures 31 to 36. More specifically, the operation of the control circuit 35E may be the operation of the control circuit 35B described with reference to Figures 31 to 36, in which the description regarding the light detection circuit 32B is replaced with the description regarding the light detection circuit 32E.

[0466] [1.8.2 Effects, etc.] The control device 3E described above is a control device that controls a refrigeration cycle circuit 2E in which a working fluid 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and includes a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2E, and a control circuit 35E that stops or limits the operation of the refrigeration cycle circuit 2E when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2E or a second state related to the working fluid 20. This configuration can improve the accuracy of detection of a disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0467] In the control device 3E, the refrigeration cycle circuit 2E includes a light absorber 11E containing a dye. The control device 3E also includes a photodetector 322E that detects light L32E in a wavelength band including the absorption wavelength of the dye and outputs the intensity of the detected light L32E as a second state. The control circuit 35E determines an index value for the amount of products generated from the working fluid by the disproportionation reaction based on the intensity of the light L32E output from the photodetector 322E. A sign of the disproportionation reaction is when the amount of products or the increase in the amount of products within a predetermined period of time exceeds a predetermined amount. This configuration improves the accuracy of detection of the disproportionation reaction of the working fluid 20 and enables improved suppression of the disproportionation reaction.

[0468] It can be said that the control device 3E described above executes the following control method. The control method stops or restricts the operation of the refrigeration cycle circuit 2E when a sign of a disproportionation reaction is detected based on at least one of a first state related to the drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2E and a second state related to the working fluid 20. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0469] The control method includes determining an indicator value of the amount of product produced by the disproportionation reaction from the working fluid 20 based on the second state. The indication of the disproportionation reaction is that the amount of product or an increase in the amount of product within a predetermined period of time is equal to or greater than a predetermined amount. This configuration can improve the accuracy of detection of the disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0470] The control method executed by the control device 3E can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3E that controls a refrigeration cycle circuit 2E through which a working fluid 20 containing a refrigerant component in which a disproportionation reaction may occur circulates, and causes the computer system to execute a process to stop or limit the operation of the refrigeration cycle circuit 2E when a sign of a disproportionation reaction is detected based on at least one of a first state related to a drive circuit 31 that drives the compressor 4 of the refrigeration cycle circuit 2E or a second state related to the working fluid 20. This configuration can improve the accuracy of detection of a disproportionation reaction of the working fluid 20 and enable improved suppression of the disproportionation reaction.

[0471] The refrigeration cycle apparatus 1E described above includes a refrigeration cycle circuit 2E through which the working medium 20 circulates, and a light absorber 11E disposed in the refrigeration cycle circuit 2E so as to be in contact with the working medium 20. The light absorber 11E contains a dye whose absorbance changes upon reacting with a product (D) produced by a chemical reaction of the working medium 20. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E.

[0472] In the refrigeration cycle device 1E, the dye contains a nickel complex. This configuration enables improvement in the accuracy of detecting an abnormality in the refrigeration cycle circuit 2E.

[0473] In the refrigeration cycle device 1E, the dye contains a boron compound having an aromatic substituent. This configuration enables improved accuracy in detecting abnormalities in the refrigeration cycle circuit 2E.

[0474] In the refrigeration cycle device 1E, the light absorber 11E is refrigerating machine oil with a dye dissolved therein. This configuration can increase the possibility that the dye of the light absorber 11E will come into contact with and react with the product (D).

[0475] The refrigeration cycle apparatus 1E further includes a light source device 321E that emits light L32E in a wavelength band that includes the absorption wavelength of the dye inside the refrigeration cycle circuit 2E, and a light detection device 322E that receives the light L32E and outputs the intensity of the received light L32E. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E.

[0476] In the refrigeration cycle device 1E, the wavelength band includes the maximum absorption wavelength of the dye. This configuration enables improvement in the accuracy of detecting an abnormality in the refrigeration cycle circuit 2E.

[0477] In the refrigeration cycle apparatus 1E, the light source device 321E emits a plurality of light beams L32E-1 and L32E-2 having different wavelength bands, and the light detection device 322E receives the plurality of light beams L32E-1 and L32E-2 and outputs the intensities of the received plurality of light beams L32E-1 and L32E-2. This configuration uses the intensities of the plurality of light beams L32E-1 and L32E-2 having different wavelength bands to reduce the influence of the colors of substances other than the pigment of the light absorber 11E, for example, the influence of a change in the hue of refrigeration oil.

[0478] In the refrigeration cycle apparatus 1E, the light source device 321E emits light beams L32E-1 and L32E-2 to a portion 22 between the discharge pipe 402 of the compressor 4 and the condenser (first heat exchanger 5, second heat exchanger 7) of the refrigeration cycle circuit 2E. This configuration enables improvement in the accuracy of detecting an abnormality in the refrigeration cycle circuit 2E.

[0479] The refrigeration cycle apparatus 1E includes a control circuit 35E that controls the operation of the refrigeration cycle circuit 2E. The control circuit 35E stops or limits the operation of the refrigeration cycle circuit 2E when the intensity of the light beams L32E-1 and L32E-2 output from the photodetector 322E satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0480] In the refrigeration cycle device 1E, the wavelength band includes an absorption wavelength at which the absorbance of the dye decreases due to a reaction between the dye and the product (D). The predetermined condition is that the ratio of the index value of the intensity of the light L32E-1 and L32E-2 at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of the light L32E-1 and L32E-2 at a first time point is 110% or more. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E.

[0481] In the refrigeration cycle device 1E, the wavelength band includes an absorption wavelength at which the absorbance of the dye increases due to a reaction between the dye and the product (D). The predetermined condition is that the ratio of the index value of the intensity of the light L32E-1 and L32E-2 at a second time point, which is a predetermined time after the first time point, to the index value of the intensity of the light L32E-1 and L32E-2 at a first time point is 90% or less. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E.

[0482] The refrigeration cycle apparatus 1E described above executes an optical detection method for a refrigeration cycle circuit 2E through which a working medium 20 circulates. This optical detection method involves emitting light L32E in a wavelength band including the absorption wavelength of the dye to a light absorber 11E that contains a dye and is arranged in the refrigeration cycle circuit 2E so as to be in contact with the working medium 20, receiving the light L32E, and outputting the intensity of the received light L32E. The dye has the property of reacting with a product (D) produced by a chemical reaction of the working medium 20 and changing its absorbance. This configuration enables early detection of abnormalities in the refrigeration cycle circuit 2E.

[0483] The control device 3E described above can be said to execute the following control method. The control method is executed by the control device 3E, which controls a refrigeration cycle circuit 2E through which the working medium 20 circulates. The refrigeration cycle circuit 2E includes a light absorber 11E containing a dye, and the control device 3E includes a photodetector 322E. The control method receives light L32E in a wavelength band including the absorption wavelength of the dye using the photodetector 322E, outputs the intensity of the received light L32E, and stops or limits operation of the refrigeration cycle circuit 2E when the intensity of the light L32E output from the photodetector 322E satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0484] The control method executed by the control device 3E can be realized by a computer system executing a program. This program is executed by a computer system included in the control device 3E, which controls a refrigeration cycle circuit 2E through which the working medium 20 circulates. The refrigeration cycle circuit 2E includes a light absorber 11E containing a dye, and the control device 3E includes a photodetector 322E. The program receives light L32E in a wavelength band including the absorption wavelength of the dye using the photodetector 322E, outputs the intensity of the received light L32E, and stops or limits operation of the refrigeration cycle circuit 2E when the intensity of the light L32E output from the photodetector 322E satisfies a predetermined condition. This configuration enables early detection of an abnormality in the refrigeration cycle circuit 2E. Furthermore, this configuration enables suppression of the disproportionation reaction of the working medium 20.

[0485] [1.9 Ninth Embodiment] [1.9.1 Configuration] Fig. 46 is a schematic diagram of a compressor 4 and a control device 3F of a refrigeration cycle apparatus according to embodiment 9. The refrigeration cycle apparatus according to embodiment 9 includes a configuration similar to that of the refrigeration cycle apparatus 1E according to embodiment 8, and therefore Fig. 42 and reference numerals will be used for similar configurations as necessary.

[0486] The control device 3F includes a drive circuit 31, a light detection circuit 32F, a first protection device 33, a second protection device 34, and a control circuit 35E.

[0487] 46 is a schematic diagram of the light detection circuit 32F. In this embodiment, the light detection circuit 32F enables evaluation of an abnormality in the refrigeration cycle circuit 2E by the light absorption body 11F.

[0488] The light absorber 11F contains a dye and is disposed in the refrigeration cycle circuit 2E so as to be able to come into contact with the working medium 20. In this embodiment, the light absorber 11F is a support supporting the dye. The support is, for example, a porous body. The porous body may be an inorganic or organic porous body. Examples of inorganic porous bodies include mesoporous silica. Examples of organic porous bodies include synthetic resin membranes or paper. Porous bodies can ensure a larger surface area, thereby increasing the likelihood that the dye will come into contact with the working medium 20. It is preferable that the porous body has the property of transmitting light L32 without blocking it. The light absorber 11F is fixed in a predetermined location in the refrigeration cycle circuit 2E. In this embodiment, the light absorber 11F is disposed in the sealed container 40 of the compressor 4. For example, the light absorber 11F is located in the region between the electric motor 42 and the discharge pipe 402. In the light absorber 11F, unlike the light absorber 11E, the dye is not dispersed throughout the refrigeration cycle circuit 2E but is located in a predetermined location, so that the possibility of contact with the working medium 20 is reduced, but light L32 can be reliably applied.

[0489] The light detection circuit 32F includes a light source device 321F and a light detection device 322F. The light source device 321F emits light L32E into the compressor 4 of the refrigeration cycle circuit 2E. As a result, light L32 is emitted into the sealed container 40 of the compressor 4, and the light L32E strikes the light absorber 11F inside the sealed container 40 of the compressor 4. In this embodiment, the light source device 321F is disposed inside the sealed container 40 of the compressor 4. For example, the light source device 321F is located in the area between the motor 42 and the discharge pipe 402. This increases the likelihood that the light L32E will strike the dye. This configuration improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2E. The light detection device 322E receives light L32E from inside the compressor 4 of the refrigeration cycle circuit 2E. In this embodiment, the light detection device 322E is disposed inside the sealed container 40 of the compressor 4. For example, the optical detection device 322E is located in the region between the electric motor 42 and the discharge pipe 402. The optical detection device 322E may also be located based on the positional relationship between the compression mechanism 41 of the compressor and the electric motor 42. Specifically, the optical detection device 322E may be located such that the electric motor 42 is located between the optical detection device 322E and the compression mechanism 41 of the compressor 4. This can improve the intensity of the light L32E received by the optical detection device 322E. This configuration can improve the accuracy of detecting abnormalities in the refrigeration cycle circuit 2E.

[0490] [1.9.2 Effects, etc.] In the refrigeration cycle apparatus described above, the light source device 321F emits light L32E into the inside of the compressor 4 of the refrigeration cycle circuit 2E. This configuration makes it possible to improve the accuracy of detecting an abnormality in the refrigeration cycle circuit 2E.

[0491] In the refrigeration cycle device, the light absorber 11F is a support that supports a dye. This configuration ensures that the dye is not dispersed throughout the refrigeration cycle circuit 2E but is located in a predetermined location, allowing the dye to be reliably irradiated with light L32E.

[0492] In the refrigeration cycle device, the support includes a porous body. This configuration can increase the possibility that the dye will come into contact with the working medium 20.

[0493] [1.10 Tenth Embodiment] [1.10.1 Configuration] Fig. 48 is a schematic diagram of a compressor 4 and a control device 3G of a refrigeration cycle apparatus according to embodiment 10. The refrigeration cycle apparatus according to embodiment 10 includes the same configuration as the refrigeration cycle apparatus 1 according to embodiment 1, and therefore Fig. 1 and reference numerals will be used for the same configuration as necessary.

[0494] The control device 3G includes a drive circuit 31, a temperature detection device 32G, a first protection device 33, a second protection device 34, and a control circuit 35G.

[0495] The temperature detection device 32G detects the temperature [K] of the working medium 20 in a portion of the refrigeration cycle circuit 2. In this embodiment, the second state is the temperature [K] of the working medium 20 in a portion of the refrigeration cycle circuit 2. Here, the portion of the refrigeration cycle circuit 2 is the inside of the compressor 4. As an example, the temperature detection device 32G detects the temperature in the sealed container 40 and outputs a temperature signal indicating the temperature to the control circuit 35G. That is, the temperature detection device 32G detects the temperature of the working medium 20 in the sealed container 40 of the compressor 4, which is part of the refrigeration cycle circuit 2, and outputs the temperature signal as the second state. The temperature detection device 32G may have a conventionally known configuration, such as a thermocouple. Note that the portion of the refrigeration cycle circuit 2 is not limited to the inside of the compressor 4, but may be the suction pipe 401 or the discharge pipe 402 of the sealed container 40, or any part of the piping path of the refrigeration cycle circuit 2.

[0496] The control circuit 35G may be realized, for example, by a computer system including at least one processor (microprocessor) and one or more memories. The computer system may also include one or more A / D converters. For example, the one or more A / D converters are used to convert the temperature signal from the temperature sensing device 32G from analog to digital format. The control circuit 35G, like the control circuit 35, controls the drive circuit 31, the first protection device 33, and the second protection device 34.

[0497] The control circuit 35G further executes processing to suppress the disproportionation reaction of the working medium 20 circulating through the refrigeration cycle circuit 2, based on the temperature indicated by the temperature signal output from the temperature detection device 32G. The disproportionation reaction of the working medium 20 is considered to be caused by heat and radicals. For example, the disproportionation reaction of the working medium 20 is considered to progress when radicals are generated under high temperature and high pressure. Furthermore, when the temperature of the working medium 20 is very high, it is considered that radicals are likely to be generated. From this perspective, when the control circuit 35G detects a sign of the disproportionation reaction based on a second state related to the working medium 20 (in this embodiment, the temperature [K] of the working medium 20 in a part of the refrigeration cycle circuit 2), it stops or restricts the operation of the refrigeration cycle circuit 2 (drive circuit 31).

[0498] In this embodiment, the control circuit 35G detects that the temperature [K] of the working medium 20 in a part of the refrigeration cycle circuit 2 is equal to or higher than the threshold temperature [K] as a sign of the disproportionation reaction.

[0499] The threshold temperature [K] may be determined based on the temperature during rated operation. In this embodiment, the threshold temperature [K] is set to be 10 times or more the maximum value [K] in the temperature range during rated operation. As an example, if the average temperature during rated operation is 353 K and the maximum value in the temperature range during rated operation is 393 K, the threshold temperature may be set to 3930 K or more.

[0500] The threshold temperature [K] may be determined based on an absolute standard. For example, the threshold temperature [K] may be 2000. In this case, the sign of the disproportionation reaction is when the temperature [K] of the working fluid in a part of the refrigeration cycle circuit becomes 2000 K or higher.

[0501] [1.10.2 Effects, etc.] In the refrigeration cycle device described above, the second state is the temperature [K] of the working medium 20 in a part of the refrigeration cycle circuit 2. A sign of a disproportionation reaction is when the temperature [K] of the working medium in a part of the refrigeration cycle circuit is 10 times or more the maximum value [K] in the temperature range during rated operation. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0502] In the refrigeration cycle device described above, the second state is the temperature [K] of the working medium 20 in a part of the refrigeration cycle circuit 2. A sign of a disproportionation reaction is when the temperature [K] of the working medium in a part of the refrigeration cycle circuit is 2000 K or higher. This configuration can improve the accuracy of detection of the disproportionation reaction of the working medium 20 and enable improved suppression of the disproportionation reaction.

[0503] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0504] In the following, reference will be made to the symbols used in embodiment 1, even though they are applicable to any of the above embodiments 1 to 9. However, this is merely to simplify the description and is not intended to exclude application to embodiments 2 to 10.

[0505] In one modified example, in the control circuit 35, stopping the operation of the drive circuit 31 may include one or more of stopping the output of AC output power, stopping the output of DC output power, or stopping the input of input power. Restricting the operation of the drive circuit 31 may include one or more of reducing the set value of the amplitude of the AC output power or reducing the set value of the frequency of the AC output power.

[0506] In one modified example, the control circuit 35 may stepwise stop or decelerate the electric motor 42. As an example, the control circuit 35 may stepwise reduce at least one of the amplitude and frequency of the AC output power, thereby stepwise reducing the effective value of the AC output power supplied to the electric motor 42.

[0507] In one modified example, the operation of the control circuit 35 is not necessarily limited to the operation shown in the flowcharts of FIGS. 4 to 9. The flowcharts of FIGS. 4 to 9 are merely examples. For example, in the operation of the control circuit 35, the processing of steps S19 to S23, i.e., the processing of stopping the output of AC output power and stopping the input of input power, is not essential. In the operation of the control circuit 35, the processing of steps S24 to S28, i.e., the processing of stopping the output of AC output power and reducing the set value of the amplitude of the AC output power after the waiting time has elapsed, is not essential. Similarly, in the operation of the control circuit 35, the processing of steps S29 to S34, steps S35 to S41, or steps S42 to S51 are not essential.

[0508] The control circuit 35 does not necessarily have to stop or restrict the operation of the drive circuit 31 in different ways depending on the time difference between the first time when the detected voltage first becomes less than the second voltage and the second time when the detected voltage next becomes less than the second voltage, or the number of times the detected voltage becomes less than the second voltage.

[0509] In one modified example, the operation of the control circuit 35A is not necessarily limited to the operations shown in the flowcharts of Figures 13 to 26. The flowcharts shown in Figures 13 to 26 are merely examples. For example, the threshold value for the first light is not limited to the first to third threshold values, and only a single threshold value may be used, or two or more threshold values ​​may be used. The same applies to the threshold value for the second light.

[0510] In one modified example, the operation of the control circuit 35B is not necessarily limited to the operation shown in the flowcharts of FIGS. 31 to 36. The flowcharts of FIGS. 31 to 36 are merely examples. For example, in the operation of the control circuit 35B, the processing of steps S219 to S223, i.e., the processing of stopping the output of AC output power and stopping the input of input power, is not essential. In the operation of the control circuit 35B, the processing of steps S224 to S228, i.e., the processing of stopping the output of AC output power and reducing the set value of the amplitude of the AC output power after the waiting time has elapsed, is not essential. Similarly, in the operation of the control circuit 35B, the processing of steps S229 to S234, steps S235 to S241, or steps S242 to S251 are not essential. This also applies to the control circuits 35C and 35E.

[0511] The control circuit 35B does not necessarily have to stop or limit the operation of the refrigeration cycle circuit 2B in a different manner depending on the time difference between the first time when the intensity of the light L32B first satisfies the predetermined condition and the second time when the intensity of the light L32B next satisfies the predetermined condition, or the number of times when the intensity of the light L32B satisfies the predetermined condition. This also applies to the control circuits 35C and 35E.

[0512] In one modified example, the photodetector device 32A is not limited to a configuration including multiple photodetectors 321A, 322A, and may include a single photodetector. The arrangement of the multiple photodetectors 321A, 322A is not particularly limited as long as they are arranged in positions within the sealed container 40 where they can detect light that may contribute to the occurrence of a disproportionation reaction. All of the multiple photodetectors 321A, 322A do not necessarily have to be located in positions where they can detect light, and it is sufficient that at least one of the multiple photodetectors 321A, 322A can detect light.

[0513] In one modification, the light detection circuit 32B may be configured to emit light L32B to the working medium 20 at a different point in the refrigeration cycle circuit 2B. This improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2B. The light detection circuit 32B does not necessarily have to be disposed inside the sealed container 40. For example, a window may be provided in the refrigeration cycle circuit 2B to enable light emission and detection of the light intensity. In this case, the light detection circuit 32B itself can be disposed outside the refrigeration cycle circuit 2B.

[0514] In one modified example, the light source device 321B does not necessarily have to include the first light source 3211-1 and the second light source 3211-2, and may be configured to radiate light by splitting it from a single light source using a beam splitter, an optical fiber, etc. The number of light sources 3211 in the light source device 321B does not have to be two, but may be one, or three or more.

[0515] In one modified example, the light source device 321B may emit multiple light beams L32B having different wavelength bands. The photodetector 322B may receive the multiple light beams L32B and output the intensities of the received multiple light beams L32B. In this case, the photodetector 322B outputs a photodetection signal to the control circuit 35B may include one or multiple photodetection signals indicating the intensities of the multiple light beams having different wavelength bands. Using multiple intensities of light beams having different wavelength bands can reduce the influence of substances other than the insoluble components, for example, the influence of a change in the hue of the refrigerating machine oil.

[0516] In one modified example, the number of photodetectors 3220 in the photodetection device 322B may be one, three, or more, instead of two. The first photodetector 3220-1 does not necessarily have to be disposed opposite the first light source 3211-1, but may be located on the optical path of the light L32B-1 from the first light source 3211-1. For example, the optical path of the light L32B-1 may be bent by a mirror or the like, in which case the first photodetector 3220-1 does not necessarily have to be located opposite the first light source 3211-1. The same applies to the second photodetector 3220-2.

[0517] In one modified example, the position of the bubble removal mechanism 21 is not limited to the position shown in Fig. 27. The bubble removal mechanism 21 aims to reduce the effect of bubbles B on the light detection circuit 32B, and therefore may be located upstream of the portion of the refrigeration cycle circuit 2B where light L32B is emitted by the light source device 321B. For example, the bubble removal mechanism 21 may be located inside the compressor 4. In particular, the bubble removal mechanism 21 may be located inside the sealed container 40 or the suction pipe 401 of the compressor 4.

[0518] In one modified example, the photodetector circuit 32C may be configured to emit the excitation light Le to multiple locations in the refrigeration cycle circuit 2C. This improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2C. The photodetector circuit 32C does not necessarily have to be located inside the sealed container 40. For example, a window may be provided in the refrigeration cycle circuit 2C to enable light emission and detection of the light intensity. In this case, the photodetector circuit 32C itself can be located outside the refrigeration cycle circuit 2C.

[0519] In one modification, the light detection circuit 32E may be configured to emit light L32E to the working medium 20 at different points in the refrigeration cycle circuit 2E. This improves the accuracy of detecting abnormalities in the refrigeration cycle circuit 2E. The light detection circuit 32E does not necessarily have to be located inside the sealed container 40. For example, a window may be provided in the refrigeration cycle circuit 2E to enable light emission and detection of the light intensity. In this case, the light detection circuit 32E itself can be located outside the refrigeration cycle circuit 2E.

[0520] In one modified example, the light source device 321E does not necessarily have to include the first light source 3213-1 and the second light source 3213-2, and may be configured to radiate light by splitting it from a single light source using a beam splitter, an optical fiber, etc. The number of light sources 3213 in the light source device 321E does not have to be two, but may be one, or three or more.

[0521] In one modified example, the number of photodetectors 3223 of the photodetector device 322E may be one, three, or more, instead of two. The first photodetector 3223-1 does not necessarily have to be disposed opposite the first light source 3213-1, but may be located on the optical path of the light L32E-1 from the first light source 3213-1. For example, the optical path of the light L32E-1 may be bent by a mirror or the like, in which case the first photodetector 3223-1 does not necessarily have to be located opposite the first light source 3213-1. The same applies to the second photodetector 3223-2.

[0522] In one modified example, the light source device 321B does not necessarily have to be included in the control device 3E. A light source external to the refrigeration cycle apparatus 1B can be used as the light source device 321B. This also applies to the light source devices 321C and 321E.

[0523] In one modified example, the first protection device 33 is not limited to a circuit configuration including the switches Su, Sv, and Sw, and may include a circuit configuration that adjusts the magnitude of the AC output power, for example, the magnitude of the voltage, output from the drive circuit 31 to the electric motor 42. The first protection device 33 may be disposed within the drive circuit 31.

[0524] In one modified example, the second protection device 34 is not limited to a circuit configuration including the switches S1 and S2, and may include a circuit configuration that adjusts the magnitude of the input power, for example, the magnitude of the voltage, input fro...

Claims

1. A method for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component in which a disproportionation reaction may occur circulates, comprising: when detecting a sign of the disproportionation reaction based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working medium, stopping or limiting the operation of the refrigeration cycle circuit; determining a number of electrical discharge events occurring in the compressor based on the first condition; The sign of the disproportionation reaction is that the number of occurrences of the discharge phenomenon is equal to or greater than a predetermined number corresponding to the stored energy. Control method.

2. the second state is a temperature [K] of the working medium in a part of the refrigeration cycle circuit, The sign of the disproportionation reaction is that the temperature [K] of the working fluid in the part of the refrigeration cycle circuit is 10 times or more the maximum value [K] in the temperature range during rated operation. The control method of claim 1.

3. the second state is a temperature [K] of the working medium in a part of the refrigeration cycle circuit, The sign of the disproportionation reaction is that the temperature [K] of the working fluid in the part of the refrigeration cycle circuit is 2000 K or higher. The control method of claim 1.

4. A method for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component capable of undergoing a disproportionation reaction circulates, comprising: when detecting a sign of the disproportionation reaction based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working medium, stopping or limiting the operation of the refrigeration cycle circuit; determining a number of times to emit light of the working medium in the compressor based on the second condition; The sign of the disproportionation reaction is that the number of times that the working fluid emits light is equal to or greater than a predetermined number. Control method.

5. A method for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component capable of undergoing a disproportionation reaction circulates, comprising: when detecting a sign of the disproportionation reaction based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working medium, stopping or limiting the operation of the refrigeration cycle circuit; determining an indicator value of the amount of product produced from the working medium by the disproportionation reaction based on the second state; The sign of the disproportionation reaction is that the amount of the product or the increase in the amount of the product within a predetermined period of time is equal to or greater than a predetermined amount. Control method.

6. the product comprises at least one of an intermediate product or a final product; the intermediate product is a thermodynamically unstable chemical species; the final product is a thermodynamically stable species; The control method of claim 5.

7. A control device for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component in which a disproportionation reaction may occur circulates, a drive circuit for driving a compressor of the refrigeration cycle circuit; a control circuit that stops or limits operation of the refrigeration cycle circuit when a sign of the disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working fluid; Equipped with The control circuit determines the number of occurrences of a discharge phenomenon in the compressor based on the first state; The sign of the disproportionation reaction is that the number of occurrences of the discharge phenomenon is equal to or greater than a predetermined number corresponding to the stored energy. Control device.

8. the drive circuit includes a converter circuit that outputs DC output power based on input power from a power source so that a voltage becomes a first voltage, and an inverter circuit that outputs AC output power to a compressor of the refrigeration cycle circuit based on the DC output power, the control device includes a voltage detector that detects the DC output power and outputs a detected voltage indicating a voltage of the DC output power as the first state; The control circuit determines the number of times a discharge phenomenon has occurred in the compressor based on the number of times the detected voltage has become less than a second voltage that is equal to or less than the first voltage. The control device of claim 7.

9. A control device for controlling a refrigeration cycle circuit in which a working medium containing a refrigerant component in which a disproportionation reaction may occur circulates, comprising: a drive circuit for driving a compressor of the refrigeration cycle circuit; a control circuit that stops or limits operation of the refrigeration cycle circuit when a sign of the disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working fluid; Equipped with the control device includes a light detection device that detects light in a sealed container of the compressor of the refrigeration cycle circuit and outputs an intensity of the light as the second state; The control circuit determines the number of times to emit light to the working medium in the compressor based on the number of times the intensity of the light exceeds the light threshold; The sign of the disproportionation reaction is that the number of times that the working fluid emits light is equal to or greater than a predetermined number. Control device.

10. A control device for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component in which a disproportionation reaction may occur circulates, comprising: a drive circuit for driving a compressor of the refrigeration cycle circuit; a control circuit that stops or limits operation of the refrigeration cycle circuit when a sign of the disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working fluid; Equipped with the control device includes a light detection device that receives light through the inside of the refrigeration cycle circuit and outputs the intensity of the received light as the second state, the control circuit determines an indicator value of the amount of product produced from the working fluid by the disproportionation reaction based on the intensity of the light; The sign of the disproportionation reaction is that the amount of the product or the increase in the amount of the product within a predetermined period of time is equal to or greater than a predetermined amount. Control device.

11. A control device for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component in which a disproportionation reaction may occur circulates, comprising: a drive circuit for driving a compressor of the refrigeration cycle circuit; a control circuit that stops or limits operation of the refrigeration cycle circuit when a sign of the disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working fluid; Equipped with the refrigeration cycle circuit includes a fluorescent material containing a fluorescent dye, the control device includes a light detection device that detects light of a wavelength corresponding to a fluorescence wavelength of the fluorescent dye and outputs the intensity of the detected light as the second state; the control circuit determines an indicator value of the amount of product produced from the working fluid by the disproportionation reaction based on the intensity of the light output from the light detection device; The sign of the disproportionation reaction is that the amount of the product or the increase in the amount of the product within a predetermined period of time is equal to or greater than a predetermined amount. Control device.

12. A control device for controlling a refrigeration cycle circuit in which a working fluid containing a refrigerant component in which a disproportionation reaction may occur circulates, comprising: a drive circuit for driving a compressor of the refrigeration cycle circuit; a control circuit that stops or limits operation of the refrigeration cycle circuit when a sign of the disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working fluid; Equipped with the refrigeration cycle circuit includes a light absorber containing a dye, the control device includes a light detection device that receives light in a wavelength band that includes an absorption wavelength of the dye and outputs the intensity of the received light as the second state; the control circuit determines an indicator value of the amount of product produced from the working fluid by the disproportionation reaction based on the intensity of the light output from the light detection device; The sign of the disproportionation reaction is that the amount of the product or the increase in the amount of the product within a predetermined period of time is equal to or greater than a predetermined amount. Control device.

13. A control device according to any one of claims 7 to 12; The refrigeration cycle circuit; Equipped with Refrigeration cycle equipment.

14. The refrigerant component comprises an ethylene-based fluoroolefin. The refrigeration cycle device of claim 13.

15. A program executed by a computer system provided in a control device that controls a refrigeration cycle circuit in which a working fluid containing a refrigerant component in which a disproportionation reaction may occur circulates, causing the computer system to execute a process of stopping or limiting operation of the refrigeration cycle circuit when a sign of the disproportionation reaction is detected based on at least one of a first state related to a drive circuit that drives a compressor of the refrigeration cycle circuit and a second state related to the working medium; causing the computer system to determine a number of electrical discharge events occurring in the compressor based on the first condition; The sign of the disproportionation reaction is that the number of occurrences of the discharge phenomenon is equal to or greater than a predetermined number corresponding to the stored energy. program.