Refrigeration cycle device

Abstract

Provided is a refrigeration cycle device whereby it becomes possible to prevent the occurrence of a disproportionation reaction of a working medium. The refrigeration cycle device (1) is provided with a control device (3) for controlling a compressor (4) in a refrigeration cycle circuit through which a working medium is circulated. The working medium contains an ethylene-based fluoroolefin as a refrigerant component. The compressor (4) is provided with: an airtight container (40) that constitutes a flow path for the working medium; and a compressing mechanism (41) and an electric motor (42) both positioned in the airtight container (40). The control device (3) is provided with: a driving circuit (31) for driving the electric motor (42); a state-detecting circuit (32) for detecting the state of at least one of the compressor (4) and the driving circuit (31); a temperature-measuring circuit (33) for measuring the internal temperature of the airtight container (40); and a control circuit (34) for controlling the driving circuit (31). The control circuit (34) halts the operation of the driving circuit (31) on the basis of the state detected by the state-detecting circuit (32), i.e., when an abnormality is detected in at least one of the compressor (4) and the driving circuit (31) and the internal temperature measured by the temperature-measuring circuit (33) is higher than a predetermined temperature.

Description

Refrigeration Cycle Equipment

[0001] The present disclosure relates to a refrigeration cycle device.

[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] International Publication No. WO 2012 / 157764 International Publication No. WO 2012 / 157765

[0004] In particular, 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.

[0005] The present disclosure provides a refrigeration cycle device that makes it possible to suppress the disproportionation reaction of a working fluid.

[0006] A refrigeration cycle device according to one aspect of the present disclosure includes a refrigeration cycle circuit including a compressor, a condenser, an expansion valve, and an evaporator, through which a working medium circulates, and a control device that controls the compressor of the refrigeration cycle circuit. The working medium includes an ethylene-based fluoroolefin as a refrigerant component. The compressor includes a sealed container that forms a flow path for the working medium, a compression mechanism located within the sealed container that compresses the working medium, and an electric motor located within the sealed container that operates the compression mechanism. The control device includes a drive circuit that drives the electric motor, a state detection circuit that detects the state of at least one of the compressor and the drive circuit, a temperature measurement circuit that measures the internal temperature of the compressor's sealed container, and a control circuit that controls the drive circuit. The control circuit detects an abnormality in at least one of the compressor and the drive circuit based on the state detected by the state detection circuit, and stops operation of the drive circuit when the internal temperature measured by the temperature measurement circuit exceeds a predetermined temperature.

[0007] Aspects of the present disclosure enable the suppression of disproportionation reactions of the working medium.

[0008] 1 is a block diagram of a configuration example of a refrigeration cycle device according to an embodiment; FIG. 2 is a schematic diagram of a configuration example of a compressor and a control device of the refrigeration cycle device of FIG. 1; FIG. 3 is a flowchart of an example of the operation of the control circuit of the control device of FIG. 2;

[0009] [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. 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.

[0010] 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.

[0011] [1.1 Configuration] Fig. 1 is a block diagram of a configuration example of a refrigeration cycle device 1 according to this embodiment. The refrigeration cycle device 1 in Fig. 1 configures, for example, an air conditioner capable of cooling operation and heating operation.

[0012] The refrigeration cycle device 1 in FIG. 1 includes a refrigeration cycle circuit 2 and a control device 3 .

[0013] The refrigeration cycle circuit 2 constitutes a flow path through which the working medium circulates. In this embodiment, the working medium contains an ethylene-based fluoroolefin as a refrigerant component. The ethylene-based fluoroolefin is preferably 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), and tetrafluoroethylene (CF ２ =CF ２ , FO1114), and monofluoroethylene (HFO-1141).

[0014] The working fluid may contain multiple types of refrigerant components. The working fluid 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, pentafluoropropane, hexafluoropropane, heptafluoropropane, 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.

[0015] The working fluid may further contain a disproportionation inhibitor that suppresses the disproportionation reaction of the ethylenic 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 1 or 2 carbon atoms. Examples of haloalkanes having 1 carbon atom (i.e., halomethanes) include (mono)iodomethane (CH ３ I), diiodomethane (CH ２ I ２ ), dibromomethane (CH ２ Br ２ ), bromomethane (CH ３Br), 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 ２ I), monobromoethane (CH ３ CH ２ Br), 1,1,1-triiodoethane (CH ３ CI ３ The working fluid may contain one or more 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.

[0016] The refrigeration cycle circuit 2 in FIG. 1 includes a compressor 4 , a first heat exchanger 5 , an expansion valve 6 , a second heat exchanger 7 , and a four-way valve 8 .

[0017] The refrigeration cycle apparatus 1 in Fig. 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.

[0018] In the refrigeration cycle circuit 2 of Fig. 1, 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.

[0019] 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 .

[0020] 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 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 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.

[0021] 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.

[0022] 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.

[0023] The control device 3 in Fig. 1 controls the compressor 4 of the refrigeration cycle circuit 2. Fig. 2 is a schematic diagram of an example of the configuration of the compressor 4 and the control device 3.

[0024] 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 in FIG. 2 includes a hermetic container 40, a compression mechanism 41, and an electric motor 42.

[0025] 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.

[0026] 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.

[0027] 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 provided 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 sheet, etc.) with 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), etc.

[0028] 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.

[0029] The control device 3 in FIG. 2 includes a drive circuit 31, a state detection circuit 32, a temperature measurement circuit 33, and a control circuit .

[0030] The drive circuit 31 drives the electric motor 42. The drive circuit 31 in FIG. 2 supplies drive power to the electric motor 42 based on power from the power supply 10. In this embodiment, the power supply 10 is an AC power supply. The drive circuit 31 supplies drive power to the electric motor 42 based on the AC power from the power supply 10. In particular, the drive circuit 31 supplies three-phase AC power as drive power to the electric motor 42. The drive circuit 31 includes a converter circuit 311 and an inverter circuit 312.

[0031] The converter circuit 311 converts AC power from the power supply 10 into DC power. The converter circuit 311 includes a rectifier circuit 311a and a smoothing circuit 311b. The rectifier circuit 311a is a diode bridge composed of multiple diodes D1 to D4. The power supply 10 is connected between the input terminals of the rectifier circuit 311a (the connection point between diodes D1 and D2 and the connection point between diodes D3 and D4), and the smoothing circuit 311b is connected between the output terminals of the rectifier circuit 311a (the connection point between diodes D1 and D3 and the connection point between diodes D2 and D4). The smoothing circuit 311b includes a series circuit of an inductor L1 and a capacitor C1, smoothes the voltage between the output terminals of the rectifier circuit 311a, and outputs the voltage across the capacitor C1. The configurations of the rectifier circuit 311a and the smoothing circuit 311b in FIG. 2 are well known, so detailed description thereof will be omitted.

[0032] The inverter circuit 312 supplies three-phase AC power to the motor 42 based on the DC power from the converter circuit 311. The inverter circuit 312 includes a plurality of arms U1, U2, V1, V2, W1, and W2. Each of the arms U1, U2, V1, V2, W1, and W2 is configured with a semiconductor switching element such as a transistor. The series circuit of the arms U1 and U2 is connected in parallel to the capacitor C1 of the converter circuit 311 and forms a U-phase leg. The series circuit of the arms V1 and V2 is connected in parallel to the capacitor C1 of the converter circuit 311 and forms a V-phase leg. The series circuit of the arms W1 and W2 is connected in parallel to the capacitor C1 of the converter circuit 311 and forms a W-phase leg. The configuration of the inverter circuit 312 in FIG. 2 is well known, so a detailed description thereof will be omitted.

[0033] The state detection circuit 32 detects the state of the drive circuit 31. The state of the drive circuit 31 is the current value of the current flowing through the drive circuit 31. In this embodiment, the current value of the current flowing through the drive circuit 31 includes the current values ​​of the output AC currents of the U-phase and W-phase legs of the drive circuit 31. The state detection circuit 32 in FIG. 2 includes a first AC current sensor 32a and a second AC current sensor 32b. The first AC current sensor 32a detects the current value of the output AC current of the U-phase leg of the drive circuit 31 and outputs a first detection signal indicating the detected current value of the output AC current to the control circuit 34. The second AC current sensor 32b detects the current value of the output AC current of the W-phase leg of the drive circuit 31 and outputs a second detection signal indicating the detected current value of the output AC current to the control circuit 34.

[0034] The temperature measurement circuit 33 measures the internal temperature of the sealed container 40 of the compressor 4. The temperature measurement circuit 33 outputs a measurement signal indicating the measured internal temperature to the control circuit 34. The temperature measurement circuit 33 is, for example, a temperature sensor located inside the sealed container 40. The temperature measurement circuit 33 is not limited to a temperature sensor located inside the sealed container 40. It is sufficient that the temperature measurement circuit 33 can directly or indirectly measure the internal temperature of the sealed container 40 of the compressor 4.

[0035] The control circuit 34 can be realized by, for example, a computer system including at least one processor (microprocessor) and one or more memories. The control circuit 34 controls the drive circuit 31. More specifically, the control circuit 34 controls the switching of the multiple arms U1, U2, V1, V2, W1, and W2 of the inverter circuit 312 of the drive circuit 31 so that the inverter circuit 312 supplies three-phase AC power to the electric motor 42 based on the DC power from the smoothing circuit 311b.

[0036] The control circuit 34 further executes processing to suppress the disproportionation reaction of the working fluid circulating through the refrigeration cycle circuit 2 based on the first and second detection signals from the state detection circuit 32 and the measurement signal from the temperature measurement circuit 33.

[0037] The disproportionation reaction of the working fluid is thought to be caused by heat and radicals. For example, it is thought that the disproportionation reaction of the working fluid progresses 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. From this perspective, the control circuit 34 is configured to detect an abnormality in the drive circuit 31 based on the state detected by the state detection circuit 32, and to stop operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature.

[0038] The control circuit 34 determines whether an abnormality has occurred in the drive circuit 31 based on the state of the drive circuit 31 detected by the state detection circuit 32. In this embodiment, the state of the drive circuit 31 is the current value of the current flowing through the drive circuit 31. The current value of the current flowing through the drive circuit 31 includes the current values ​​of the output AC current of the U-phase and W-phase legs of the drive circuit 31. In this embodiment, the abnormality in the drive circuit 31 is a current abnormality in the drive circuit 31. The current abnormality in the drive circuit 31 may include, for example, an abnormal increase in the DC component of the current flowing through the drive circuit 31. Such an abnormal increase may be caused by a failure in the refrigeration cycle apparatus 1, such as a failure in the compressor 4 or a failure in the inverter circuit 312 (e.g., a failure in any of the multiple arms U1, U2, V1, V2, W1, and W2). Therefore, if a current abnormality in the drive circuit 31 is detected, there is a possibility that a failure in the refrigeration cycle apparatus 1, such as a failure in the compressor 4 or a failure in the inverter circuit 312, has occurred. However, there are also cases where a current abnormality in the drive circuit 31 is detected due to some kind of noise or the like.

[0039] In this embodiment, the control circuit 34 compares the current value of the output AC current indicated by the first and second detection signals from the state detection circuit 32 with a predetermined current value. The predetermined current value is set appropriately by, for example, analyzing the current waveform of the drive circuit 31 when an abnormality actually occurs in the drive circuit 31. Naturally, the predetermined current value is set to be larger than the current value of the current flowing through the drive circuit 31 when no abnormality occurs in the drive circuit 31.

[0040] If at least one of the current values ​​of the output AC current indicated by the first and second detection signals exceeds a predetermined current value, the control circuit 34 determines that a current abnormality has occurred in the drive circuit 31. In other words, the control circuit 34 detects a current abnormality in response to the current value of the current flowing through the drive circuit 31 detected by the state detection circuit 32 exceeding a predetermined current value. If both of the current values ​​of the output AC current indicated by the first and second detection signals are equal to or less than the predetermined current value, the control circuit 34 determines that a current abnormality has not occurred in the drive circuit 31.

[0041] When the control circuit 34 determines that a current abnormality has occurred in the drive circuit 31 (i.e., when it detects a current abnormality in the drive circuit 31), it stops the operation of the drive circuit 31. When the control circuit 34 detects a current abnormality in the drive circuit 31, there is a possibility that the current abnormality has been caused by some kind of noise or the like. In other words, the detection of an abnormality in the drive circuit 31 may be a false detection due to noise or the like. However, for safety reasons, the control circuit 34 stops the operation of the drive circuit 31.

[0042] After stopping the operation of the drive circuit 31, the control circuit 34 compares the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 with a predetermined temperature. The predetermined temperature is, for example, lower than the safe temperature of the working medium and lower than the heat-resistant temperature of the insulating members of the electric motor 42 of the compressor 4.

[0043] The safe temperature of the working medium can be set based on the temperature at which a disproportionation reaction of the working medium may occur under pressure conditions during normal operation of the refrigeration cycle apparatus 1. As an example, the safe temperature of the working medium is set to 150°C.

[0044] The heat resistance temperature of the electric motor 42 of the compressor 4 is set, for example, based on the heat resistance temperature of the insulating members of the electric motor 42 of the compressor 4. For example, the heat resistance temperature of the insulating members of the electric motor 42 may be the heat resistance temperature of the insulating member with the lowest heat resistance temperature among the insulating members of the electric motor 42. If the refrigeration cycle apparatus 1 continues to operate with the internal temperature exceeding the heat resistance temperature, the insulating paper may be broken, increasing the possibility of a discharge occurring. As an example, the insulating member with the lowest heat resistance temperature in the electric motor 42 may be the insulating paper between the stator core (e.g., electromagnetic steel sheet) and the stator winding (e.g., magnet wire). If the heat resistance class of the insulating paper is, for example, Class E as defined in JIS C 4003, the heat resistance temperature is 120°C.

[0045] If the safe temperature of the working fluid is 150°C and the heat-resistant temperature of the electric motor 42 of the compressor 4 is 120°C, the predetermined temperature is set to a temperature lower than 120°C. In this case, taking into consideration the time difference in temperature detection between the temperature of the working fluid and the stator, heat dissipation, etc., it is advisable to set the safety margin to, for example, about 5°C. Therefore, the predetermined temperature may be set to 115°C. The safety margin depends on the distance between the temperature measurement circuit 33 and the stator or the motor efficiency, so it is not limited to 5°C and may be a value between 0 and 20°C.

[0046] The heat resistance class of insulating paper is not limited to Class E, and may be Class B, Class F, etc. If the heat resistance class is Class B, the heat resistance temperature is 130°C. If the safe temperature of the working medium is 150°C, the predetermined temperature is set to a temperature lower than 130°C, for example, 125°C. If the heat resistance class is Class F, the heat resistance temperature is 155°C. If the safe temperature of the working medium is 150°C, the predetermined temperature is set to a temperature lower than 150°C, for example, 145°C.

[0047] The control circuit 34 continues to stop the operation of the drive circuit 31 if the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 exceeds a predetermined temperature. If an abnormality occurs in the drive circuit 31 and the internal temperature exceeds the predetermined temperature, it is considered that a disproportionation reaction of the working fluid is likely to proceed. Therefore, the control circuit 34 keeps the operation of the drive circuit 31 stopped to suppress the disproportionation reaction of the working fluid. In this way, the control circuit 34 stops the operation of the drive circuit 31 when an abnormality in the drive circuit 31 is detected based on the state detected by the state detection circuit 32 and the internal temperature measured by the temperature measurement circuit 33 exceeds the predetermined temperature. In this case, the control circuit 34 outputs an error notification indicating that a disproportionation reaction may occur.

[0048] The control circuit 34 resumes operation of the drive circuit 31 if the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 is equal to or lower than a predetermined temperature. Even if an abnormality in the drive circuit 31 is detected, if the internal temperature is equal to or lower than the predetermined temperature, it is considered that the disproportionation reaction of the working fluid is unlikely to progress. Therefore, the control circuit 34 resumes operation of the drive circuit 31.

[0049] As described above, the detection of an abnormality in the drive circuit 31 may be a false detection due to noise or the like. However, if an abnormality in the drive circuit 31 is detected multiple times, there is a high possibility that an abnormality such as a malfunction of the refrigeration cycle apparatus 1 has actually occurred. In this embodiment, the number of times an abnormality in the drive circuit 31 is detected is counted. The control circuit 34 compares the number of times an abnormality in the drive circuit 31 is detected with a predetermined number corresponding to the abnormality in the drive circuit 31. If the number of detections exceeds the predetermined number, the control circuit 34 stops the operation of the drive circuit 31. In this case, the control circuit 34 outputs an error notification indicating that there is a possibility of an abnormality such as a malfunction of the refrigeration cycle apparatus 1.

[0050] As described above, in this embodiment, the control circuit 34 stops the operation of the drive circuit 31 when it detects a current abnormality in the drive circuit 31. Therefore, the control circuit 34 continues to stop the operation of the drive circuit 31 when the number of detections exceeds a predetermined number. The control circuit 34 resumes the operation of the drive circuit 31 when the number of detections is equal to or less than the predetermined number. However, if the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 exceeds the predetermined temperature, the control circuit 34 continues to stop the operation of the drive circuit 31 even if the number of detections is equal to or less than the predetermined number.

[0051] [1.2 Operation] An example of the operation of the control circuit 34 of the control device 3 of the refrigeration cycle apparatus 1 will be briefly described below with reference to Fig. 3. Fig. 3 is a flowchart showing an example of the operation of the control circuit 34 of the control device 3.

[0052] The control circuit 34 detects the state of the drive circuit 31 using the state detection circuit 32 (S11). In the present embodiment, the state of the drive circuit 31 is the current value of the current flowing through the drive circuit 31. The current value of the current flowing through the drive circuit 31 includes the current values ​​of the output AC currents of the U-phase and W-phase legs of the drive circuit 31.

[0053] The control circuit 34 determines whether an abnormality has occurred in the drive circuit 31 based on the state detected by the state detection circuit 32 (S12). In this embodiment, the control circuit 34 compares the current value of the output AC current indicated by the first and second detection signals from the state detection circuit 32 with a predetermined current value.

[0054] If both the current values ​​of the output AC current indicated by the first and second detection signals are equal to or less than the predetermined current value, the control circuit 34 determines that no current abnormality has occurred in the drive circuit 31 (S12; NO).

[0055] If at least one of the current values ​​of the output AC currents indicated by the first and second detection signals exceeds a predetermined current value, the control circuit 34 determines that a current abnormality has occurred in the drive circuit 31 (S12; YES), and stops the operation of the drive circuit 31 (S13).

[0056] After stopping the operation of the drive circuit 31, the control circuit 34 compares the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 with a predetermined temperature (S14).

[0057] If the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 exceeds the predetermined temperature (S14; YES), the control circuit 34 continues to stop the operation of the drive circuit 31 (S15).Then, the control circuit 34 outputs an error notification indicating that a disproportionation reaction may occur (S16).

[0058] In step S14, if the internal temperature indicated by the measurement signal from the temperature measurement circuit 33 is equal to or lower than the predetermined temperature, the control circuit 34 increments the number of times an abnormality in the drive circuit 31 has been detected by one (S17).

[0059] The control circuit 34 compares the number of times the abnormality in the drive circuit 31 has been detected with a predetermined number of times corresponding to the abnormality in the drive circuit 31 (S18).

[0060] If the number of detections exceeds a predetermined number (S18; YES), the control circuit 34 continues to stop the operation of the drive circuit 31 (S19).Then, the control circuit 34 outputs an error notification indicating that there is a possibility of an abnormality, such as a breakdown, in the refrigeration cycle apparatus 1 (S20).

[0061] In step S18, if the number of detections is equal to or less than the predetermined number of times (S18; NO), the control circuit 34 resumes the operation of the drive circuit 31 (S21).

[0062] As described above, the control circuit 34 detects an abnormality in the drive circuit 31 based on the state detected by the state detection circuit 32, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. In particular, the control circuit 34 stops the operation of the drive circuit 31 when it detects an abnormality, and continues to stop the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds the predetermined temperature. In this way, the control circuit 34 can suppress the discharge phenomenon that can generate radicals that cause the disproportionation reaction of the working fluid, and as a result, can suppress the disproportionation reaction of the working fluid.

[0063] [1.3 Effects, etc.] The refrigeration cycle apparatus 1 described above includes a refrigeration cycle circuit 2 including a compressor 4, a condenser (first heat exchanger 5, second heat exchanger 7), an expansion valve 6, and an evaporator (first heat exchanger 5, second heat exchanger 7) and through which a working medium 20 circulates, and a control device 3 that controls the compressor 4 of the refrigeration cycle circuit 2. 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 that compresses the working medium 20, and an electric motor 42 located within the sealed container 40 that operates the compression mechanism 41. The control device 3 includes a drive circuit 31 that drives the electric motor 42, a state detection circuit 32 that detects the state of the drive circuit 31, a temperature measurement circuit 33 that measures the internal temperature of the sealed container 40 of the compressor 4, and a control circuit 34 that controls the drive circuit 31. The control circuit 34 detects an abnormality in the drive circuit 31 based on the state detected by the state detection circuit 32, and when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature, the control circuit 34 stops the operation of the drive circuit 31. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0064] In the refrigeration cycle apparatus 1, when the control circuit 34 detects an abnormality, it stops the operation of the drive circuit 31, determines whether the internal temperature measured by the temperature measurement circuit 33 after the operation of the drive circuit 31 has stopped exceeds a predetermined temperature, and continues to stop the operation of the drive circuit 31 if the internal temperature measured by the temperature measurement circuit 33 exceeds the predetermined temperature, and resumes the operation of the drive circuit 31 if the internal temperature measured by the temperature measurement circuit 33 is equal to or lower than the predetermined temperature. This configuration can enhance the effect of suppressing the disproportionation reaction of the working medium.

[0065] In the refrigeration cycle apparatus 1, the control circuit 34 counts the number of times an abnormality is detected, and when the number of detections exceeds a predetermined number corresponding to the abnormality, the control circuit 34 stops the operation of the drive circuit 31. This configuration can improve the safety of the operation of the refrigeration cycle apparatus 1.

[0066] In the refrigeration cycle apparatus 1, the state includes the current value of the current flowing in the drive circuit 31 (the current value of the output AC current of the U-phase and W-phase legs of the drive circuit 31). The abnormality includes a current abnormality in the drive circuit 31. The control circuit 34 detects the current abnormality in response to the current value of the current flowing in the drive circuit 31 detected by the state detection circuit 32 exceeding a predetermined current value. This configuration makes it possible to suppress the disproportionation reaction of the working medium caused by the abnormality in the drive circuit 31.

[0067] In the refrigeration cycle apparatus 1, the predetermined temperature is lower than the safe temperature of the working medium 20 and lower than the heat-resistant temperature of the electric motor 42 of the compressor 4. This configuration makes it possible to suppress the disproportionation reaction of the working medium.

[0068] 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 suppress the disproportionation reaction of the working fluid.

[0069] 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 makes it possible to suppress the disproportionation reaction of the working fluid.

[0070] In the refrigeration cycle device 1, the working fluid 20 further contains difluoromethane as a refrigerant component. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0071] In the refrigeration cycle device 1, the working fluid 20 further contains saturated hydrocarbons. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0072] 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 makes it possible to suppress the disproportionation reaction of the working fluid.

[0073] In the refrigeration cycle device 1, the saturated hydrocarbons include n-propane. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0074] [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.

[0075] [2.1 Modification 1] FIG. 4 is a schematic diagram of a configuration example of the compressor 4 and the control device 3A of a refrigeration cycle device according to Modification 1.

[0076] The control device 3A in FIG. 4 includes a drive circuit 31, a state detection circuit 32A, a temperature measurement circuit 33, and a control circuit 34A.

[0077] The state detection circuit 32A detects the state of the drive circuit 31. The state of the drive circuit 31 is the current value of the current flowing through the drive circuit 31. In the first modification, the current value of the current flowing through the drive circuit 31 includes the current value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31. The state detection circuit 32A in FIG. 4 is, for example, a shunt resistor connected between the connection point of the diode D4 and the capacitor C1 in the converter circuit 311 and the connection point of the legs U2, V2, and W2 in the inverter circuit 312. The voltage across the state detection circuit 32A indicates the current value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31.

[0078] The control circuit 34A determines whether an abnormality has occurred in the drive circuit 31 based on the state of the drive circuit 31 detected by the state detection circuit 32A. In the first modification, the state of the drive circuit 31 is the current value of the current flowing through the drive circuit 31. The current value of the current flowing through the drive circuit 31 includes the current value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31. In the first modification, the abnormality in the drive circuit 31 is also a current abnormality in the drive circuit 31. The current abnormality in the drive circuit 31 may include, for example, an abnormal increase in the DC component of the current flowing through the drive circuit 31. Such an abnormal increase may be caused by a failure in the refrigeration cycle apparatus 1, such as a failure in the compressor 4 or a failure in the inverter circuit 312 (e.g., a failure in any of the arms U1, U2, V1, V2, W1, and W2). Therefore, if a current abnormality in the drive circuit 31 is detected, there is a possibility that a failure in the refrigeration cycle apparatus 1, such as a failure in the compressor 4 or a failure in the inverter circuit 312, has occurred. However, there are also cases where a current abnormality in the drive circuit 31 is detected due to some kind of noise or the like.

[0079] The control circuit 34A compares the value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31, which is obtained from the voltage across the state detection circuit 32A, with a predetermined current value. The predetermined current value is set appropriately by, for example, analyzing the current waveform of the drive circuit 31 when an abnormality actually occurs in the drive circuit 31. Naturally, the predetermined current value is set to be larger than the current value of the current flowing through the drive circuit 31 when no abnormality occurs in the drive circuit 31.

[0080] The control circuit 34A determines that a current abnormality has occurred in the drive circuit 31 if the current value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31 exceeds a predetermined current value. That is, the control circuit 34A detects a current abnormality in response to the current value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31 exceeding the predetermined current value. The control circuit 34A determines that a current abnormality has not occurred in the drive circuit 31 if the current value of the DC current flowing between the converter circuit 311 and the inverter circuit 312 of the drive circuit 31 is equal to or less than the predetermined current value.

[0081] The control circuit 34A detects an abnormality in the drive circuit 31 (abnormal current in the drive circuit 31) based on the state detected by the state detection circuit 32A, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. In particular, the control circuit 34A stops the operation of the drive circuit 31 when it detects an abnormality, and continues to stop the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds the predetermined temperature. In this way, the control circuit 34A can suppress the discharge phenomenon that can generate radicals that cause the disproportionation reaction of the working fluid, and as a result, can suppress the disproportionation reaction of the working fluid.

[0082] As described above, in Modification 1, the control device 3A includes the drive circuit 31 that drives the electric motor 42, the state detection circuit 32A that detects the state of the drive circuit 31, the temperature measurement circuit 33 that measures the internal temperature of the sealed container 40 of the compressor 4, and the control circuit 34A that controls the drive circuit 31. The control circuit 34A detects an abnormality in the drive circuit 31 based on the state detected by the state detection circuit 32A, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0083] In the first modification, the state includes a current value of the current flowing through the drive circuit 31. The abnormality includes a current abnormality in the drive circuit 31. The control circuit 34A detects the current abnormality in response to the current value of the current flowing through the drive circuit 31, detected by the state detection circuit 32A, exceeding a predetermined current value. This configuration makes it possible to suppress the disproportionation reaction of the working medium caused by the abnormality in the drive circuit 31.

[0084] [2.2 Modification 2] FIG. 5 is a schematic diagram of a configuration example of the compressor 4 and the control device 3B of a refrigeration cycle device according to modification 2. In FIG.

[0085] The control device 3B in FIG. 5 includes a drive circuit 31, a state detection circuit 32B, a temperature measurement circuit 33, and a control circuit 34B.

[0086] The state detection circuit 32B detects the state of the compressor 4. The state of the compressor 4 is the current value of the phase current of the compressor 4. The current value of the phase current of the compressor 4 includes the current values ​​of the U-phase, V-phase, and W-phase currents. The state detection circuit 32B in FIG. 5 includes a U-phase shunt resistor Ru, a V-phase shunt resistor Rv, and a W-phase shunt resistor Rw. The U-phase shunt resistor Ru is inserted between the U-phase arm of the inverter circuit 312 and the U-phase stator winding of the electric motor 42 of the compressor 4. The V-phase shunt resistor Rv is inserted between the V-phase arm of the inverter circuit 312 and the V-phase stator winding of the electric motor 42 of the compressor 4. The W-phase shunt resistor Rw is inserted between the W-phase arm of the inverter circuit 312 and the W-phase stator winding of the electric motor 42 of the compressor 4. The voltages across the shunt resistors Ru, Rv, and Rw of the state detection circuit 32B indicate the current values ​​of the U-phase, V-phase, and W-phase currents, respectively.

[0087] The control circuit 34B determines whether an abnormality in the compressor 4 has occurred based on the state of the compressor 4 detected by the state detection circuit 32B. The abnormality in the compressor 4 includes an abnormality related to a layer short in the compressor 4. The abnormality related to a layer short in the compressor 4 may include the layer short in the compressor 4 itself, an abnormality that may cause a layer short in the compressor 4, and an abnormality that may be caused by a layer short in the compressor 4. Specific examples of an abnormality related to a layer short in the compressor 4 include a layer short in the compressor 4, a ground fault in the compressor 4, and open-phase operation of the compressor 4. If an imbalance in the phase currents of the compressor 4 occurs, an abnormality related to a layer short in the compressor 4 may have occurred.

[0088] The control circuit 34B determines whether an imbalance has occurred in the phase currents of the compressor 4 based on the current values ​​of the phase currents of the compressor 4 obtained from the state detection circuit 32B. If the U-phase, V-phase, and W-phase currents of the compressor 4 are not equal in amplitude and 120 degrees out of phase with each other, an imbalance has occurred in the phase currents of the compressor 4.

[0089] If an imbalance in the phase currents of the compressor 4 occurs, the control circuit 34B determines that an abnormality related to a layer short in the compressor 4 has occurred. That is, the control circuit 34B detects an abnormality related to a layer short in the compressor 4 in response to an imbalance in the phase currents of the compressor 4. If an imbalance in the phase currents of the compressor 4 does not occur, the control circuit 34B determines that an abnormality related to a layer short in the compressor 4 has not occurred.

[0090] The control circuit 34B detects an abnormality in the compressor 4 (an abnormality related to a layer short in the compressor 4) based on the state detected by the state detection circuit 32B, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. In particular, the control circuit 34B stops the operation of the drive circuit 31 when it detects an abnormality, and continues to stop the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds the predetermined temperature. In this way, the control circuit 34B can suppress the discharge phenomenon that can generate radicals that cause the disproportionation reaction of the working fluid, and as a result, can suppress the disproportionation reaction of the working fluid.

[0091] As described above, in Modification 2, the control device 3B includes the drive circuit 31 that drives the electric motor 42, the state detection circuit 32B that detects the state of the compressor 4, the temperature measurement circuit 33 that measures the internal temperature of the sealed container 40 of the compressor 4, and the control circuit 34B that controls the drive circuit 31. The control circuit 34B detects an abnormality in the compressor 4 based on the state detected by the state detection circuit 32B, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0092] In the second modification, the state includes a current value of a phase current of the compressor 4. The abnormality includes an abnormality related to a layer short of the compressor 4. The control circuit 34B detects the abnormality related to a layer short of the compressor 4 in response to an imbalance in the phase current of the compressor 4. This configuration makes it possible to suppress a disproportionation reaction of the working medium caused by the abnormality of the compressor 4.

[0093] [2.3 Modification 3] FIG. 6 is a schematic diagram of a configuration example of the compressor 4 and the control device 3C of a refrigeration cycle device according to Modification 3.

[0094] The control device 3C in FIG. 6 includes a drive circuit 31, a state detection circuit 32C, a temperature measurement circuit 33, and a control circuit 34C.

[0095] The state detection circuit 32C detects the state of the compressor 4. The state of the compressor 4 is the rotation speed of the electric motor 42 of the compressor 4. The state detection circuit 32C in FIG. 6 includes a rotation speed sensor that measures the rotation speed of the electric motor 42 of the compressor 4. The rotation speed sensor may be of a known configuration such as an electromagnetic pickup, a proximity sensor, a photoelectric sensor, or a laser sensor.

[0096] The control circuit 34C determines whether an abnormality has occurred in the compressor 4 based on the state of the compressor 4 detected by the state detection circuit 32C. The abnormality in the compressor 4 includes an abnormality related to a layer short in the compressor 4. The abnormality related to a layer short in the compressor 4 may include the layer short in the compressor 4 itself, an abnormality that may cause a layer short in the compressor 4, and an abnormality that may be caused by a layer short in the compressor 4. Specific examples of abnormalities related to a layer short in the compressor 4 include a layer short in the compressor 4, a ground fault in the compressor 4, and open-phase operation of the compressor 4. If a deviation in the rotation speed of the electric motor 42 of the compressor 4 occurs, an abnormality related to a layer short in the compressor 4 may have occurred.

[0097] The control circuit 34C determines whether a deviation in the rotation speed of the electric motor 42 of the compressor 4 has occurred based on the rotation speed of the electric motor 42 of the compressor 4 obtained from the state detection circuit 32C. The control circuit 34C sets the operating frequencies (switching frequencies) of the multiple legs U1, U2, V1, V2, W1, and W2 of the inverter circuit 312 of the drive circuit 31 so that the rotation speed of the electric motor 42 of the compressor 4 becomes the target rotation speed. If no abnormality has occurred in the compressor 4, the rotation speed of the electric motor 42 of the compressor 4 detected by the state detection circuit 32C falls within a predetermined range based on the target rotation speed. If the rotation speed of the electric motor 42 of the compressor 4 detected by the state detection circuit 32C is not within the predetermined range, the control circuit 34C determines that a deviation in the rotation speed of the electric motor 42 of the compressor 4 has occurred.

[0098] If a deviation in the rotation speed of the electric motor 42 of the compressor 4 occurs, the control circuit 34C determines that an abnormality related to a layer short in the compressor 4 has occurred. In other words, the control circuit 34C detects an abnormality related to a layer short in the compressor 4 in response to a deviation in the rotation speed of the electric motor 42 of the compressor 4. If a deviation in the rotation speed of the electric motor 42 of the compressor 4 does not occur, the control circuit 34C determines that an abnormality related to a layer short in the compressor 4 has not occurred.

[0099] The control circuit 34C detects an abnormality in the compressor 4 (an abnormality related to a layer short in the compressor 4) based on the state detected by the state detection circuit 32C, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. In particular, the control circuit 34C stops the operation of the drive circuit 31 when it detects an abnormality, and continues to stop the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds the predetermined temperature. In this way, the control circuit 34C can suppress the discharge phenomenon that can generate radicals that cause the disproportionation reaction of the working fluid, and as a result, can suppress the disproportionation reaction of the working fluid.

[0100] The control device 3C described above includes a drive circuit 31 that drives the electric motor 42, a state detection circuit 32C that detects the state of the compressor 4, a temperature measurement circuit 33 that measures the internal temperature of the sealed container 40 of the compressor 4, and a control circuit 34C that controls the drive circuit 31. The control circuit 34C detects an abnormality in the compressor 4 based on the state detected by the state detection circuit 32C, and stops the operation of the drive circuit 31 when the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature. This configuration makes it possible to suppress the disproportionation reaction of the working fluid.

[0101] In the control device 3C, the state includes the rotation speed of the electric motor 42 of the compressor 4. The abnormality includes an abnormality related to a layer short of the compressor 4. The control circuit 34C detects the abnormality related to a layer short of the compressor 4 in response to a deviation in the rotation speed of the electric motor 42 of the compressor 4. This configuration makes it possible to suppress the disproportionation reaction of the working medium caused by the abnormality of the compressor 4.

[0102] [2.4 Other Modifications] In one modification, the state detection circuits 32, 32A, 32B, and 32C may be modified as appropriate. For example, the current value of the current flowing through the drive circuit 31 detected by the state detection circuit 32 is not limited to the current value of the output AC current of the U-phase and W-phase legs of the drive circuit 31. The current value of the current flowing through the drive circuit 31 detected by the state detection circuit 32 may include at least one of the current values ​​of the output AC current of the U-phase, V-phase, and W-phase legs of the drive circuit 31. For example, the state detection circuit 32A may be a shunt resistor connected between the connection point between the inductor L1 and the capacitor C1 in the converter circuit 311 and the connection point between the legs U1, V1, and W1 in the inverter circuit 312. The state detection circuit 32A is not limited to a shunt resistor. The state detection circuit 32A may be a well-known DC current sensor. For example, the state detection circuit 32B is not limited to a shunt resistor. The state detection circuit 32B may be a well-known AC current sensor.

[0103] In one modified example, the refrigeration cycle apparatus may include at least one of the state detection circuits 32 and 32A and at least one of the state detection circuits 32B and 32C. That is, the refrigeration cycle apparatus may detect an abnormality in both the compressor 4 and the drive circuit 31. The number of times an abnormality is detected may be counted for each state detection circuit.

[0104] In one modified example, when an abnormality is detected, the control circuits 34, 34A, 34B, and 34C do not necessarily have to stop the operation of the drive circuit 31. The control circuits 34, 34A, 34B, and 34C may stop the operation of the drive circuit 31 when an abnormality is detected and the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature.

[0105] In one modification, the control circuits 34, 34A, 34B, and 34C do not necessarily need to count the number of times an abnormality is detected.

[0106] In one variant, when an abnormality is detected, the control circuits 34, 34A, 34B, and 34C may stop the operation of the drive circuit 31 only while the internal temperature measured by the temperature measurement circuit 33 exceeds a predetermined temperature.

[0107] In one modified example, the refrigeration cycle device is not limited to an air conditioner configured with one indoor unit connected to one outdoor unit (so-called room air conditioner (RAC)). The refrigeration cycle device may be an air conditioner configured with multiple indoor units connected to one or multiple outdoor units (so-called package air conditioner (PAC) or building multi-air conditioner (VRF)). Alternatively, the refrigeration cycle device is not limited to an air conditioner, and may be a freezing or refrigeration device such as a refrigerator or a freezer.

[0108] [3. Aspects] As is clear from the above-described embodiments and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiments. Note that, in consideration of readability of the text, the reference numerals in parentheses may be omitted from the second and subsequent times.

[0109] The first aspect is a refrigeration cycle device (1) including a refrigeration cycle circuit (2) including a compressor (4), a condenser (first heat exchanger 5, second heat exchanger 7), an expansion valve (6), and an evaporator (first heat exchanger 5, second heat exchanger 7), through which a working medium (20) circulates, and a control device (3; 3A; 3B; 3C) for controlling the compressor (4) of the refrigeration cycle circuit (2). 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) that compresses the working medium (20), and an electric motor (42) located within the sealed container (40) that operates the compression mechanism (41). The control device (3; 3A; 3B; 3C) includes a drive circuit (31) that drives the electric motor (42), a state detection circuit (32; 32A; 32B; 32C) that detects the state of at least one of the compressor (4) and the drive circuit (31), a temperature measurement circuit (33) that measures the internal temperature of the sealed container (40) of the compressor (4), and a control circuit (34; 34A; 34B; 34C) that controls the drive circuit (31). The control circuit (34; 34A; 34B; 34C) detects an abnormality in at least one of the compressor (4) and the drive circuit (31) based on the state detected by the state detection circuit (32; 32A; 32B; 32C), and stops operation of the drive circuit (31) when the internal temperature measured by the temperature measurement circuit (33) exceeds a predetermined temperature. This aspect makes it possible to suppress the disproportionation reaction of the working fluid.

[0110] A second aspect is a refrigeration cycle apparatus (1) based on the first aspect. In the second aspect, when the control circuit (34; 34A; 34B; 34C) detects the abnormality, it stops the operation of the drive circuit (31), determines whether the internal temperature measured by the temperature measurement circuit (33) after the operation of the drive circuit (31) has stopped exceeds the predetermined temperature, continues to stop the operation of the drive circuit (31) if the internal temperature measured by the temperature measurement circuit (33) exceeds the predetermined temperature, and resumes the operation of the drive circuit (31) if the internal temperature measured by the temperature measurement circuit (33) is equal to or lower than the predetermined temperature. This aspect can enhance the effect of suppressing the disproportionation reaction of the working medium.

[0111] A third aspect is the refrigeration cycle apparatus (1) based on the second aspect. In the third aspect, the control circuit (34; 34A; 34B; 34C) counts the number of times the abnormality is detected, and stops the operation of the drive circuit (31) when the number of times the abnormality is detected exceeds a predetermined number corresponding to the abnormality. This aspect can improve the safety of the operation of the refrigeration cycle apparatus (1).

[0112] A fourth aspect is a refrigeration cycle apparatus (1) based on any one of the first to third aspects. In the fourth aspect, the state includes a current value of a current flowing through the drive circuit (31). The abnormality includes a current abnormality in the drive circuit (31). The control circuit (34; 34A) detects the current abnormality in response to the current value of the current flowing through the drive circuit (31), detected by the state detection circuit (32; 32A), exceeding a predetermined current value. This aspect makes it possible to suppress a disproportionation reaction of the working medium caused by an abnormality in the drive circuit (31).

[0113] A fifth aspect is a refrigeration cycle apparatus (1) based on any one of the first to fourth aspects. In the fifth aspect, the state includes at least one of a current value of a phase current of the compressor (4) and a rotation speed of the electric motor (42) of the compressor (4). The abnormality includes an abnormality related to a layer short of the compressor (4). The control circuit (34B; 34C) detects the abnormality related to a layer short of the compressor (4) in response to at least one of an imbalance in the phase current of the compressor (4) and a deviation in the rotation speed of the electric motor (42) of the compressor (4). This aspect makes it possible to suppress a disproportionation reaction of the working medium caused by an abnormality of the compressor (4).

[0114] A sixth aspect is a refrigeration cycle apparatus (1) based on any one of the first to fifth aspects. In the sixth aspect, the predetermined temperature is lower than a safe temperature of the working medium (20) and lower than a heat-resistant temperature of the electric motor (42) of the compressor (4). This aspect makes it possible to suppress a disproportionation reaction of the working medium.

[0115] A seventh aspect is a refrigeration cycle device (1) based on any one of the first to sixth aspects. In the seventh aspect, the ethylene-based fluoroolefin includes an ethylene-based fluoroolefin that undergoes a disproportionation reaction. This aspect makes it possible to suppress the disproportionation reaction of the working fluid.

[0116] An eighth aspect is a refrigeration cycle device (1) based on any one of the first to seventh aspects. In the eighth aspect, the ethylene-based fluoroolefin is 1,1,2-trifluoroethylene, trans-1,2-difluoroethylene, cis-1,2-difluoroethylene, 1,1-difluoroethylene, tetrafluoroethylene, or monofluoroethylene. This aspect makes it possible to suppress the disproportionation reaction of the working fluid.

[0117] A ninth aspect is a refrigeration cycle apparatus (1) based on any one of the first to eighth aspects. In the ninth aspect, the working fluid (20) further contains difluoromethane as a refrigerant component. This aspect makes it possible to suppress a disproportionation reaction of the working fluid.

[0118] A tenth aspect is a refrigeration cycle device (1) based on any one of the first to ninth aspects. In the tenth aspect, the working medium (20) further contains saturated hydrocarbons. This aspect makes it possible to suppress disproportionation reactions of the working medium.

[0119] An eleventh aspect is the refrigeration cycle apparatus (1) based on the tenth aspect. In the eleventh aspect, the working fluid (20) contains a haloalkane having 1 or 2 carbon atoms as a disproportionation inhibitor for suppressing the disproportionation reaction of the ethylene-based fluoroolefin. This aspect makes it possible to suppress the disproportionation reaction of the working fluid.

[0120] A twelfth aspect is a refrigeration cycle apparatus (1) based on the tenth aspect. In the twelfth aspect, the saturated hydrocarbon includes n-propane. This aspect makes it possible to suppress the disproportionation reaction of the working fluid.

[0121] The second to twelfth aspects are optional elements and are not essential.

[0122] The present disclosure is applicable to a refrigeration cycle device, specifically, a refrigeration cycle device in which a working fluid contains an ethylene-based fluoroolefin as a refrigerant component.

[0123] REFRIGERATION CYCLE DEVICE 1 REFRIGERATION CYCLE CIRCUIT 20 WORKING MEDIUM 3, 3A, 3B, 3C CONTROL DEVICE 31 DRIVE CIRCUIT 32, 32A, 32B, 32C STATE DETECTION CIRCUIT 33 TEMPERATURE MEASUREMENT CIRCUIT 34, 34A, 34B, 34C CONTROL CIRCUIT 4 COMPRESSOR 40 SEALED CONTAINER 41 COMPRESSION MECHANISM 42 ELECTRIC MOTOR 5 FIRST HEAT EXCHANGER (CONDENSER, EVAPORATOR) 6 EXPANSION VALVE 7 SECOND HEAT EXCHANGER (CONDENSER, EVAPORATOR)

Claims

1. a refrigeration cycle circuit including a compressor, a condenser, an expansion valve, and an evaporator, in which a working medium circulates; a control device for controlling the compressor of the refrigeration cycle circuit; Equipped with the working fluid contains an ethylene-based fluoroolefin as a refrigerant component, The compressor is a sealed container that forms a flow path for the working medium; a compression mechanism located within the sealed container and compressing the working medium; an electric motor located within the sealed container for operating the compression mechanism; Equipped with The control device a drive circuit for driving the electric motor; a state detection circuit for detecting a state of at least one of the compressor and the drive circuit; a temperature measurement circuit that measures an internal temperature of the sealed container of the compressor; a control circuit for controlling the drive circuit; and the control circuit detects an abnormality in at least one of the compressor and the drive circuit based on the state detected by the state detection circuit, and stops operation of the drive circuit when the internal temperature measured by the temperature measurement circuit exceeds a predetermined temperature. Refrigeration cycle equipment.

2. The control circuit When the abnormality is detected, the operation of the drive circuit is stopped. determining whether the internal temperature measured by the temperature measurement circuit after the operation of the drive circuit has stopped exceeds the predetermined temperature; If the internal temperature measured by the temperature measurement circuit exceeds the predetermined temperature, the operation of the drive circuit continues to be stopped, and if the internal temperature measured by the temperature measurement circuit is equal to or lower than the predetermined temperature, the operation of the drive circuit resumes. The refrigeration cycle device according to claim 1.

3. The control circuit Counting the number of times the abnormality is detected; When the number of times of detection exceeds a predetermined number corresponding to the abnormality, the operation of the drive circuit is stopped. The refrigeration cycle device according to claim 2.

4. the state includes a current value of a current flowing through the drive circuit; the abnormality includes a current abnormality in the drive circuit, the control circuit detects the current abnormality in response to the current value of the current flowing through the drive circuit detected by the state detection circuit exceeding a predetermined current value. The refrigeration cycle device according to any one of claims 1 to 3.

5. the state includes at least one of a phase current of the compressor and a rotation speed of the motor of the compressor; the abnormality includes an abnormality related to a layer short circuit in the compressor, the control circuit detects an abnormality related to a layer short in the compressor in response to at least one of an imbalance in phase currents of the compressor and a deviation in rotation speed of the motor of the compressor. The refrigeration cycle device according to any one of claims 1 to 3.

6. The predetermined temperature is lower than a safe temperature of the working medium and lower than a heat-resistant temperature of the motor of the compressor. The refrigeration cycle device according to any one of claims 1 to 3.

7. The ethylenic fluoroolefin includes an ethylenic fluoroolefin that undergoes a disproportionation reaction. The refrigeration cycle device according to any one of claims 1 to 3.

8. The ethylenic fluoroolefin is 1,1,2-trifluoroethylene, trans-1,2-difluoroethylene, cis-1,2-difluoroethylene, 1,1-difluoroethylene, tetrafluoroethylene, or monofluoroethylene; The refrigeration cycle device according to any one of claims 1 to 3.

9. The working medium further contains difluoromethane as the refrigerant component. The refrigeration cycle device according to any one of claims 1 to 3.

10. The working medium further comprises a saturated hydrocarbon. The refrigeration cycle device according to any one of claims 1 to 3.

11. the working fluid contains a haloalkane having 1 or 2 carbon atoms as a disproportionation inhibitor that suppresses the disproportionation reaction of the ethylenic fluoroolefin, The refrigeration cycle device according to any one of claims 1 to 3.

12. The saturated hydrocarbons include n-propane. The refrigeration cycle device according to claim 10.