Refrigeration cycle device

Abstract

To provide a refrigeration cycle device that suppresses a disproportionation reaction of refrigerant that occurs in a refrigeration circuit by increasing an amount of refrigerant recovery without installing a refrigerant recovery receiver.SOLUTION: A refrigeration cycle device includes: a refrigerant state recognition unit which recognizes a state of a refrigerant discharged from a compressor on the basis of a temperature detected by a refrigerant temperature sensor and a pressure detected by a refrigerant pressure sensor; a control unit which executes a refrigerant circulation operation to activate the compressor with an on-off valve opened, terminates the refrigerant circulation operation when the state of the refrigerant recognized by the refrigerant state recognition unit is in a prescribed first disproportionation suppression requiring state during execution of the refrigerant circulation operation, and executes a refrigerant recovery operation to activate the compressor and a first blowing fan with the on-off valve closed.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Patent Document 1 discloses a configuration in which a discharged refrigerant recovery receiver is provided between the discharge side of the compressor and the gas side of the outdoor heat exchanger via a refrigerant branch pipe in a refrigeration circuit filled with a refrigerant containing a fluorohydrocarbon that has the property of causing a disproportionation reaction. In the above configuration, when the refrigerant on the discharge side of the compressor satisfies a predetermined condition for causing a disproportionation reaction, the discharge side of the compressor is communicated with the discharged refrigerant recovery receiver and the discharged refrigerant is stored in the discharged refrigerant recovery receiver, thereby reducing damage to the refrigeration circuit or suppressing the disproportionation reaction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-123971 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a refrigeration cycle apparatus that can suppress a disproportionation reaction of a refrigerant occurring in a refrigeration circuit by increasing the amount of refrigerant recovered without providing a receiver for recovering the refrigerant. [Means for solving the problem]

[0005] The refrigeration cycle apparatus according to the present disclosure is configured by connecting a compressor, a radiator, an on-off valve, and an evaporator in a ring shape through refrigerant piping, and has a refrigeration circuit in which a refrigerant containing a fluorocarbon hydrogen having a property of causing a disproportionation reaction is sealed, and the refrigeration cycle apparatus includes a first blower fan that cools the radiator, a refrigerant temperature sensor that detects the temperature of the refrigerant discharged from the compressor, a refrigerant pressure sensor that detects the pressure of the refrigerant discharged from the compressor, a refrigerant state recognition unit that recognizes a state of the refrigerant discharged from the compressor based on the temperature detected by the refrigerant temperature sensor and the pressure detected by the refrigerant pressure sensor, and a control unit that performs a refrigerant circulation operation in which the compressor is operated with the on-off valve open, and when the state of the refrigerant recognized by the refrigerant state recognition unit reaches a predetermined first disproportionation suppression required state during the refrigerant circulation operation, terminates the refrigerant circulation operation, and performs a refrigerant recovery operation in which the compressor and the first blower fan are operated with the on-off valve closed. Effect of the Invention

[0006] The refrigeration cycle device of the present disclosure can suppress the disproportionation reaction of the refrigerant occurring in the refrigeration circuit by increasing the amount of refrigerant recovered without providing a receiver for recovering the refrigerant. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating the configuration of a refrigeration cycle device according to a first embodiment and its operation during heating operation. [Diagram 2] FIG. 1 is an explanatory diagram of the operation of the refrigeration cycle device in the cooling mode according to the first embodiment. [Diagram 3] Control block diagram of a refrigeration cycle device according to a first embodiment [Figure 4] Flowchart of disproportionation suppression processing in the first embodiment [Diagram 5] FIG. 1 is an explanatory diagram of necessary conditions for suppressing disproportionation of a refrigerant in the first embodiment. [Figure 6] FIG. 1 is an explanatory diagram of the operation of the refrigerant recovery operation of the refrigeration cycle device according to the first embodiment. [Figure 7] A configuration diagram of a refrigeration cycle device in embodiment 2 and an explanatory diagram of the operation during heating operation. [Figure 8] FIG. 13 is an explanatory diagram of the operation of the refrigeration cycle device in the cooling mode according to the second embodiment. [Figure 9] Control block diagram of a refrigeration cycle device in embodiment 2 [Figure 10] 11 is a first flowchart of the disproportionation suppression process according to the second embodiment. [Figure 11] 2 is a second flowchart of the disproportionation suppression process according to the second embodiment. [Figure 12] FIG. 13 is an explanatory diagram of the operation of the refrigerant recovery operation of the refrigeration cycle device in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (The knowledge and other information that formed the basis of this disclosure)

[0009] At the time when the inventors of the present invention arrived at the idea of ​​the present disclosure, there was a technology in which a discharged refrigerant recovery receiver, which is branched and connected via a refrigerant branch pipe, is provided between the discharge side of the compressor and the gas side of the outdoor heat exchanger in a refrigeration cycle device having a refrigeration circuit filled with a refrigerant containing a fluorohydrocarbon that has a property of causing a disproportionation reaction. In the above technology, when the refrigerant on the discharge side of the compressor satisfies a predetermined condition for causing a disproportionation reaction, the discharge side of the compressor is communicated with the discharged refrigerant circuit receiver, and the discharged refrigerant is stored in the discharged refrigerant recovery receiver, thereby reducing damage to the refrigeration circuit or suppressing the disproportionation reaction.

[0010] However, there is an inconvenience that the size of the refrigeration cycle device becomes large in order to secure a space for providing a receiver for storing the refrigerant, and in the case of a commercial air conditioner that is charged with a large amount of refrigerant, there is an inconvenience that the recovery of the refrigerant that may cause a disproportionation reaction becomes insufficient. The inventors have discovered a problem of avoiding these inconveniences, and have come to constitute the subject of the present disclosure in order to solve the problem. In view of the above, the present disclosure provides a refrigeration cycle apparatus that can suppress the disproportionation reaction of a refrigerant occurring in a refrigeration circuit by increasing the amount of refrigerant recovered without providing a receiver for recovering the refrigerant.

[0011] Hereinafter, the embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming more redundant than necessary and to facilitate understanding by those skilled in the art. It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0012] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS. [1-1. Configuration] In Fig. 1, the refrigeration cycle device 1 includes an outdoor unit 2 and an indoor unit 3 connected by a refrigeration circuit 10. A refrigerant containing a fluorohydrocarbon that has a property of causing a disproportionation reaction is sealed in the refrigeration circuit 10. The specifications of the refrigerant will be described in detail later. The refrigeration circuit 10 is configured by connecting a compressor 11 that compresses the refrigerant, an indoor heat exchanger 12 that functions as a radiator (during heating operation) or an evaporator (during cooling operation), an outdoor expansion valve 14 that has an opening / closing valve function, and an outdoor heat exchanger 15 that functions as an evaporator (during heating operation) or a radiator (during cooling operation) in sequence in a ring shape by refrigerant piping 19.

[0013] The outdoor expansion valve 14 is an opening adjustment valve whose opening is changed by a stepping motor or the like. A four-way valve 17 is provided in the refrigerant piping 19 between the compressor 11 and the indoor heat exchanger 12. The four-way valve 17 switches the direction in which the refrigerant discharged from the compressor 11 flows. That is, the four-way valve 17 switches the direction in which the refrigerant flows between a first flow state shown in FIG. 1 and a second flow state shown in FIG. 2.

[0014] The first flow state shown in Fig. 1 corresponds to a heating operation, in which the refrigerant discharged from the compressor 11 flows in the direction of the compressor 11 → four-way valve 17 → indoor heat exchanger 12 → outdoor expansion valve 14 → outdoor heat exchanger 15 → four-way valve 17 → compressor 11, as shown by the dashed arrows in Fig. 1, with the indoor heat exchanger 12 functioning as a radiator and the outdoor heat exchanger 15 functioning as an evaporator. The second flow state shown in Fig. 2 corresponds to a cooling operation, in which the refrigerant discharged from the compressor 11 flows in the direction of the compressor 11 → four-way valve 17 → outdoor heat exchanger 15 → outdoor expansion valve 14 → indoor heat exchanger 12 → four-way valve 17 → compressor 11, as shown by the dashed arrows in Fig. 2, with the outdoor heat exchanger 15 functioning as a radiator and the indoor heat exchanger 12 functioning as a condenser.

[0015] The outdoor unit 2 includes a compressor 11, an outdoor heat exchanger 15, an outdoor expansion valve 14, a four-way valve 17, and an outdoor fan 16 that cools the outdoor heat exchanger 15. The outdoor fan 16 cools the refrigerant flowing through the outdoor heat exchanger 15 by blowing air to the outdoor heat exchanger 15 to cool the outdoor heat exchanger 15. The outdoor fan 16 corresponds to a second blower fan in the present disclosure. In addition, the outdoor fan 16 corresponds to a first blower fan in the present disclosure when the outdoor heat exchanger 15 functions as a radiator. Furthermore, the outdoor unit 2 includes a refrigerant temperature sensor 20 provided near the outlet of the compressor 11 to detect the temperature of the refrigerant discharged from the compressor 11, a refrigerant pressure sensor 21 provided near the outlet of the compressor 11 to detect the pressure of the refrigerant discharged from the compressor 11, and an outdoor air temperature sensor 22 that detects the outdoor air temperature.

[0016] The indoor unit 3 includes an indoor heat exchanger 12, an indoor fan 13 for cooling the indoor heat exchanger 12, an indoor temperature sensor 24 for detecting the temperature (indoor temperature) of the room in which the indoor unit 3 is installed, and a controller 5 for controlling the operation of the refrigeration cycle apparatus 1. The indoor fan 13 cools the indoor heat exchanger 12, thereby cooling the refrigerant circulating through the indoor heat exchanger 12. The indoor fan 13 corresponds to a first blower fan in the present disclosure when the indoor heat exchanger 12 functions as a radiator.

[0017] 3, the controller 5 is a control unit including a processor 50, a memory 60, etc., and the memory 60 stores a program 61 for controlling the refrigeration cycle apparatus 1 and control data 62 including data for determining a disproportionation necessary state, which will be described later. The controller 5 is connected to the refrigerant temperature sensor 20, the refrigerant pressure sensor 21, the outdoor air temperature sensor 22, and the indoor temperature sensor 24, and detection signals of the refrigerant temperature sensor 20, the refrigerant pressure sensor 21, the outdoor air temperature sensor 22, and the indoor temperature sensor 24 are input to the controller 5.

[0018] In addition, the controller 5 is connected to the compressor 11, the outdoor expansion valve 14, the four-way valve 17, the indoor fan 13, and the outdoor fan 16, and the operations of the compressor 11, the outdoor expansion valve 14, the four-way valve 17, the indoor fan 13, and the outdoor fan 16 are controlled by control signals output from the controller 5. In addition, the controller 5 communicates with a remote control 6 wirelessly or via a wire, and the controller 5 performs the heating operation shown in Fig. 1 or the cooling operation shown in Fig. 3 in response to an operation of the remote control 6 by a user.

[0019] The processor 50 reads and executes the program 61, thereby functioning as a refrigerant state recognition unit 51 and a control unit 52. The refrigerant state recognition unit 51 recognizes the state of the refrigerant discharged from the compressor 11 based on the temperature detected by the refrigerant temperature sensor 20 and the pressure detected by the refrigerant pressure sensor 21.

[0020] The control unit 52 executes the heating operation shown in Fig. 1 and the cooling operation shown in Fig. 2 as the refrigerant operation of the present disclosure for circulating the refrigerant in the refrigeration circuit 10. As shown in Fig. 1, the control unit 52 executes the heating operation by setting the four-way valve 17 to a first flow state, setting the outdoor expansion valve 14 to an open state, and operating the compressor 11, the outdoor fan 16, and the indoor fan 13. Also, as shown in Fig. 2, the control unit 52 executes the cooling operation by setting the four-way valve 17 to a second flow state, setting the outdoor expansion valve 14 to an open state, and operating the compressor 11, the outdoor fan 16, and the indoor fan 13.

[0021] When performing heating operation and when performing cooling operation, the control unit 52 controls the rotation speed of the compressor 11, the opening of the outdoor expansion valve 14, the rotation speed of the outdoor fan 16, and the rotation speed of the indoor fan 13 based on the operating conditions (set temperature, set air volume, etc.) set by the remote control 6, the refrigerant temperature detected by the refrigerant temperature sensor 20, the refrigerant pressure detected by the refrigerant pressure sensor 21, the outdoor air temperature detected by the outdoor air temperature sensor 22, the indoor temperature detected by the indoor temperature sensor 24, etc.

[0022] [1-2. Disproportionation suppression treatment] The control unit 52 monitors the state of the refrigerant recognized by the refrigerant state recognition unit 51 during the heating operation or the cooling operation, and when the state of the refrigerant becomes a first disproportionation suppression necessary state described later, executes a disproportionation suppression process to switch to a refrigerant recovery operation and recover the refrigerant. The execution procedure of the disproportionation suppression process will be described below with reference to the flowchart shown in Fig. 4. The control unit 52 executes the process according to the flowchart shown in Fig. 4 during the heating operation and the cooling operation.

[0023] 4 is a process performed by refrigerant state recognition unit 51. In step S1, refrigerant state recognition unit 51 recognizes the state of the refrigerant discharged from compressor 11 based on a combination of the temperature and pressure of the refrigerant, based on the temperature detected by refrigerant temperature sensor 20 and the pressure detected by refrigerant pressure sensor 21. Subsequent steps S2 to S6, S10, and S11 are processes performed by control unit 52.

[0024] In step S2, the control unit 52 judges whether the state of the refrigerant recognized by the refrigerant state recognition unit 51 is a first disproportionation response necessary state. Here, the disproportionation response necessary state will be described with reference to Fig. 5. Fig. 5 is a graph showing a region where disproportionation of the refrigerant occurs depending on a combination of refrigerant pressure and temperature, with the vertical axis set to refrigerant pressure and the horizontal axis set to refrigerant temperature. The region AR1 shown by diagonal lines in Fig. 5 is a region where disproportionation of the refrigerant occurs, and a response judgment curve is set with a margin on the side of the region AR2 where disproportionation of the refrigerant does not occur, relative to the boundary curve between the region AR1 where disproportionation of the refrigerant occurs and the region AR2 where disproportionation of the refrigerant does not occur.

[0025] 4 illustrates a coordinate position (T1, P1) where the refrigerant temperature is T1 and the pressure is P1, and since R1 is located on the AR1 side of the corresponding judgment curve, the control unit 52 determines that the refrigerant is in a state requiring disproportionation response. On the other hand, R2 illustrates a coordinate position (T2, P2) where the refrigerant temperature is T2 and the pressure is P2, and since R2 is located within AR2, the control unit 52 determines that the refrigerant is not in a state requiring disproportionation response.

[0026] If the state of the refrigerant is in a state requiring disproportionation response, the control unit 52 proceeds to step S3, and if the state of the refrigerant is not in a state requiring disproportionation response, the control unit 52 proceeds to step S1. In step S3, the control unit 52 recognizes the outdoor air temperature from the detection signal of the outdoor air temperature sensor 22, and recognizes the indoor temperature from the detection signal of the indoor temperature sensor 24. In the following step S4, the control unit 52 determines whether the outdoor air temperature is higher than the indoor temperature. If the outdoor air temperature is higher than the indoor temperature, the control unit 52 proceeds to step S10, and if the outdoor air temperature is equal to or lower than the indoor temperature, the control unit 52 proceeds to step S5.

[0027] Steps S10 and S11 are processes of a refrigerant recovery operation (corresponding to a first refrigerant recovery operation in the present disclosure) in which the refrigerant is recovered in the refrigerant pipe 19 of the indoor unit 3. In step S10, the control unit 52 sets the four-way valve 17 to a first circulation state. In the next step S11, the control unit 52 closes the outdoor expansion valve 14 and operates the indoor fan 13, the outdoor fan 16, and the compressor 11. This ends the cooling operation or heating operation that has been performed up to that point, and the refrigerant recovery operation is performed as shown in FIG. 6. In the refrigerant recovery operation shown in FIG. 6, since the outdoor expansion valve 14 is in a closed state, the refrigerant discharged from the compressor 11 is recovered and stored in the refrigerant pipe 19 in the range from the compressor 11 to the outdoor expansion valve 14 via the indoor heat exchanger 12.

[0028] In this case, the refrigerant is recovered on the indoor heat exchanger 12 side, where the refrigerant is easier to condense because its temperature is lower, and where the effect of lowering the refrigerant pressure and temperature is greater, thereby making it possible to enhance the effect of avoiding disproportionation of the refrigerant.

[0029] In addition, the refrigerant discharged from the compressor 11 is cooled when it flows through the indoor heat exchanger 12 cooled by the indoor fan 13, and liquefaction of the refrigerant is promoted, so that the amount of refrigerant recovered can be increased. This makes it possible to increase the amount of refrigerant recovered without providing a dedicated receiver (recovery tank) for refrigerant recovery in order to suppress disproportionation of the refrigerant.

[0030] Steps S5 and S6 are processes for recovering the refrigerant in the refrigerant piping 19 of the outdoor unit 2. In step S5, the control unit 52 sets the four-way valve 17 to the second state. In the next step S6, the control unit 52 closes the outdoor expansion valve and operates the indoor fan 13 and the compressor 11. This ends the refrigerant operation or heating operation that has been performed up to that point, and a refrigerant recovery operation is performed in which the refrigerant discharged from the compressor 11 is recovered in the refrigerant piping 19 in the range from the compressor 11 to the outdoor expansion valve 14 via the outdoor heat exchanger 15.

[0031] In this case, the refrigerant is easily condensed because its temperature is lower, and thus the effect of lowering the refrigerant pressure and temperature is greater, so that the effect of avoiding disproportionation of the refrigerant can be enhanced by recovering the refrigerant on the outdoor heat exchanger 15 side.

[0032] In addition, the refrigerant discharged from the compressor 11 is cooled when flowing through the outdoor heat exchanger 15 cooled by the outdoor fan 16, and liquefaction of the refrigerant is promoted, so that the amount of refrigerant recovered can be increased. This makes it possible to increase the amount of refrigerant recovered without providing a dedicated receiver for refrigerant recovery in order to suppress disproportionation of the refrigerant.

[0033] In addition, the process of recovering refrigerant to the indoor heat exchanger 12 side by steps S10 and S11 (refrigerant recovery by the heating cycle) and the process of recovering refrigerant to the outdoor heat exchanger 15 side by steps S5 and S6 (refrigerant recovery by the cooling cycle) may be switched as shown in the following example.

[0034] (Example 1) When the outdoor temperature is greater than the indoor temperature, a human presence sensor or the like is used to determine whether or not someone is present in the room in which the indoor unit 3 is installed, and refrigerant recovery is switched between the heating cycle and the cooling cycle. When it is detected that "no one is present," the refrigerant is recovered on the indoor heat exchanger 12 side (refrigerant recovery through the heating cycle). When it is detected that "someone is present," the refrigerant is recovered on the outdoor heat exchanger 15 side (refrigerant recovery through the cooling cycle). This makes it possible to achieve both safety and comfort. (Example 2) When the temperature difference between the outside air temperature and the room temperature is below a specified value (e.g. 5°C), the refrigerant is recovered by operating the air conditioning with comfort as the priority. For example, if the outdoor temperature is greater than the indoor temperature and the temperature difference is 3°C, refrigerant recovery is performed using the cooling cycle. This allows refrigerant recovery to prioritize the comfort of the occupants when the difference between the outdoor temperature and the indoor temperature is small and it is assumed that there is no significant difference in the refrigerant condensation performance whether refrigerant recovery is performed using the heating cycle or the cooling cycle.

[0035] In addition, if there is a risk that the refrigerant recovery process will reduce the comfort of the occupants of the room, the display unit of the remote control 6 may display a message such as, "Refrigerant recovery operation is in progress due to an abnormality. Please be careful as the temperature in the room will rise due to heating operation."

[0036] [1-3. Refrigerants used] The refrigerant used in the refrigeration cycle device 1 and the refrigeration cycle device 100 of the second embodiment described later is a working medium containing an ethylene-based fluoroolefin. The ethylene-based fluoroolefin contains, for example, one or more of 1,1,2-trifluoroethylene (HFO1123), trans-1,2-difluoroethylene (HFO1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), 1,1-difluoroethylene (HFO-1132a), tetrafluoroethylene (CF2=CF2, HFO1114), and monofluoroethylene (HFO-1141).

[0037] The working medium may contain two or more refrigerant components. That is, it may contain an ethylene-based fluoroolefin (e.g., 1,1,2-trifluoroethylene) selected from the above examples and a second refrigerant component. The second refrigerant component may be one or more refrigerants selected from hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), saturated hydrocarbons, carbon dioxide, or other refrigerants. Examples of the hydrofluorocarbons include difluoromethane, difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane, pentafluoropropane, hexafluoropropane, heptafluoropropane, pentafluorobutane, and heptafluorocyclopentane. Examples of the hydrofluoroolefins include monofluoropropene, trifluoropropene, tetrafluoropropene, pentafluoropropene, and hexafluorobutene. 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), and methylcyclobutane, but may be other hydrocarbons. The second refrigerant component may include a plurality of components. That is, the second refrigerant component may include two or more refrigerant components selected from hydrofluorocarbons, hydrofluoroolefins, saturated hydrocarbons, carbon dioxide, and other refrigerants.

[0038] The working medium used as a refrigerant in the refrigeration cycle device 1 may contain a disproportionation inhibitor in addition to the refrigerant components. The disproportionation inhibitor is, for example, a saturated hydrocarbon. The working medium may contain a disproportionation inhibitor consisting of one or more components. Saturated hydrocarbons used as disproportionation inhibitors include ethane, n-propane, cyclopropane, n-butane, cyclobutane, isobutane (2-methylpropane), methylcyclopropane, n-pentane, isopentane (2-methylbutane), neopentane (2,2-dimethylpropane), and methylcyclobutane, but may also be other saturated hydrocarbons. A particularly preferred disproportionation inhibitor is n-propane.

[0039] The disproportionation inhibitor may be, for example, a haloalkane having either one or two carbon atoms. Examples of haloalkanes having one carbon atom, i.e., halomethanes, that are used as disproportionation inhibitors include (mono)iodomethane (CH3I), diiodomethane (CH2I2), dibromomethane (CH2Br2), bromomethane (CH3Br), dichloromethane (CH2Cl2), chloroiodomethane (CH2ClI), dibromochloromethane (CHBr2Cl), tetraiodomethane (CI4), carbon tetrabromide (CBr4), bromotrichloromethane (CBrCl3), dibromodichloromethane (CBr2Cl2), tribromofluoromethane (CBr3F), fluorodiiodomethane (CHFI2), difluoroiodomethane (CHF2I), difluorodiiodomethane (CF2I2), dibromodifluoromethane (CBr2F2), and trifluoroiodomethane (CF3I), but other halomethanes may also be used. Examples of haloalkanes having two carbon atoms, i.e., haloethanes, that can be used as disproportionation inhibitors include 1,1,1-trifluoro-2-iodoethane (CF3CH2I), monoiodoethane (CH3CH2I), monobromoethane (CH3CH2Br), and 1,1,1-triiodoethane (CH3CI3).

[0040] The working fluid may contain a plurality of disproportionation inhibitors selected from the above-mentioned saturated hydrocarbons and the above-mentioned haloalkanes. The working fluid may contain one type of saturated hydrocarbon, or may be a working fluid containing two or more types of saturated hydrocarbons. The working fluid may contain one type of haloalkane, or may be a working fluid containing two or more types of haloalkanes.

[0041] A preferred example of the working medium is a mixture containing 1,1,2-trifluoroethylene and n-propane. This working medium may contain the second refrigerant component described above, or may contain other components.

[0042] Each of the above working fluids may contain inevitable impurities, such as various additives including stabilizers added for the purpose of stabilization during transportation or storage, residues or by-products of the raw materials for synthesizing the refrigerant components, and substances mixed in for other reasons.

[0043] The mass ratio of 1,1,2-trifluoroethylene and n-propane contained in the working fluid can be changed as appropriate. The capacity of the refrigeration cycle correlates with the mass ratio of the refrigerant components contained in the working fluid. Therefore, in order to maintain the capacity of the refrigeration cycle, it is desirable to configure the working fluid so that the mass of n-propane, which is a disproportionation inhibitor, is 40% or less by mass.

[0044] (Embodiment 2) The second embodiment will be described below with reference to FIGS. [2-1. Configuration] 7, a refrigeration cycle apparatus 100 includes a first outdoor unit 2a, a second outdoor unit 2b, a first indoor unit 3a, and a second indoor unit 3b, which are connected by a refrigeration circuit 101. The first outdoor unit 2a and the second outdoor unit 2b are connected in parallel, and the first indoor unit 3a and the second indoor unit 3b are also connected in parallel. A refrigerant containing fluorohydrocarbons that have a property of causing a disproportionation reaction is sealed in the refrigeration circuit 101.

[0045] The configuration of the first outdoor unit 2a and the second outdoor unit 2b is the same as that of the outdoor unit 2 of the above-mentioned embodiment 1. That is, the first outdoor unit 2a includes a compressor 11a that compresses the refrigerant, an outdoor expansion valve 14a having an on-off valve function, an outdoor heat exchanger 15a that functions as an evaporator (during heating operation) or a radiator (during cooling operation), an outdoor fan 16a that cools the outdoor heat exchanger 15a, a four-way valve 17a that switches the direction in which the refrigerant discharged from the compressor 11 flows, a refrigerant temperature sensor 20a that detects the temperature of the refrigerant discharged from the compressor 11a, a refrigerant pressure sensor 21a that detects the pressure of the refrigerant discharged from the compressor 11a, and an outdoor air temperature sensor 22a that detects the outdoor air temperature.

[0046] Similarly, the second outdoor unit 2b is equipped with a compressor 11b that compresses the refrigerant, an outdoor expansion valve 14b that has the function of an opening and closing valve, an outdoor heat exchanger 15b that functions as an evaporator (during heating operation) or a radiator (during cooling operation), an outdoor fan 16b that cools the outdoor heat exchanger 15b, a four-way valve 17b that switches the flow direction of the refrigerant discharged from the compressor 11, a refrigerant temperature sensor 20b that detects the temperature of the refrigerant discharged from the compressor 11b, and a refrigerant pressure sensor 21b that detects the pressure of the refrigerant discharged from the compressor 11a.

[0047] The configuration of the first indoor unit 3a and the second indoor unit 3b is the same as that of the indoor unit 3 of the above-mentioned embodiment 1. That is, the first indoor unit 3a is equipped with an indoor heat exchanger 12a that functions as a radiator (during heating operation) or an evaporator (during cooling operation), an indoor fan 13a that cools the indoor heat exchanger 12a, and a controller 110. Furthermore, the first indoor unit 3a is equipped with an indoor expansion valve 18a having a valve closing function, a human presence sensor 23a that detects a person in the room in which the first indoor unit 3a is installed, and an indoor temperature sensor 24a that detects the temperature of the room in which the first indoor unit 3a is installed. The human presence sensor 23a is, for example, an infrared sensor, an ultrasonic sensor, or the like.

[0048] Similarly, the second indoor unit 3b is equipped with an indoor heat exchanger 12b that functions as a radiator (during heating operation) or an evaporator (during cooling operation), an indoor fan 13b that cools the indoor heat exchanger 12b, an indoor expansion valve 18b with a valve closing function, a human presence sensor 23b that detects people in the room in which the second indoor unit 3b is installed, and an indoor temperature sensor 24b that detects the temperature of the room in which the second indoor unit 3b is installed.

[0049] 7 shows a state in which the refrigeration cycle device 100 is performing a heating operation, and the outdoor expansion valve 14a of the first outdoor unit 2a, the outdoor expansion valve 14b of the second outdoor unit 2b, the indoor expansion valve 18a of the first indoor unit 3a, and the indoor expansion valve 18b of the second indoor unit 3b are in an open state. In addition, the four-way valve 17a of the first outdoor unit 2a and the four-way valve 17b of the second outdoor unit 2b are in a first flow state. In addition, the compressor 11a and the outdoor fan 16a of the first outdoor unit 2a, the compressor 11b and the outdoor fan 16b of the second outdoor unit 2b, the indoor fan 13a of the first indoor unit 3a, and the indoor fan 13b of the second indoor unit 3b are operating.

[0050] As a result, the refrigerant discharged from the compressor 11a of the first outdoor unit 2a circulates through the route indicated by the dashed arrows: compressor 11a → four-way valve 17a → indoor heat exchanger 12a and indoor expansion valve 18 of the first indoor unit 3a and indoor heat exchanger 12b and indoor expansion valve 18b of the second indoor unit 3b → outdoor expansion valve 14a → outdoor heat exchanger 15a → four-way valve 17a → compressor 11a. Also, the refrigerant discharged from the compressor 11b of the second outdoor unit 2b circulates through the route indicated by the dashed arrows: compressor 11b → four-way valve 17b → indoor heat exchanger 12a and indoor expansion valve 18a of the first indoor unit 3a and indoor heat exchanger 12b and indoor expansion valve 18b of the second indoor unit 3b → outdoor expansion valve 14b → outdoor heat exchanger 15b → four-way valve 17b → compressor 11b.

[0051] In heating operation, the outdoor heat exchanger 15a of the first outdoor unit 2a and the outdoor heat exchanger 15b of the second outdoor unit 2b function as condensers, and the indoor heat exchanger 12a of the first indoor unit 3a and the indoor heat exchanger 12b of the second indoor unit 3b function as radiators. Then, the room in which the indoor unit 3a is installed and the room in which the indoor unit 3b is installed are heated.

[0052] 8 shows a state in which the refrigeration cycle device 100 is performing a cooling operation, and the outdoor expansion valve 14a of the first outdoor unit 2a, the outdoor expansion valve 14b of the second outdoor unit 2b, the indoor expansion valve 18a of the first indoor unit 3a, and the indoor expansion valve 18b of the second indoor unit 3b are in an open state. In addition, the four-way valve 17a of the first outdoor unit 2a and the four-way valve 17b of the second outdoor unit 2b are in a second flow state. In addition, the compressor 11a and the outdoor fan 16a of the first outdoor unit 2a, the compressor 11b and the outdoor fan 16b of the second outdoor unit 2b, the indoor fan 13a of the first indoor unit 3a, and the indoor fan 13b of the second indoor unit 3b are operating.

[0053] As a result, the refrigerant discharged from the compressor 11a of the first outdoor unit 2a circulates through the route indicated by the dashed arrows: compressor 11a → four-way valve 17a → outdoor heat exchanger 15a → outdoor expansion valve 14a → indoor expansion valve 18a and indoor heat exchanger 12a of the first indoor unit 3a, and indoor expansion valve 18b and indoor heat exchanger 12b of the second indoor unit 3b → four-way valve 17a → compressor 11a. Also, the refrigerant discharged from the compressor 11b of the second outdoor unit 2b circulates through the route indicated by the dashed arrows: compressor 11b → four-way valve 17b → outdoor heat exchanger 15b → outdoor expansion valve 14b → indoor expansion valve 18a and indoor heat exchanger 12a of the first indoor unit 3a, and indoor expansion valve 18b and indoor heat exchanger 12b of the second indoor unit 3b → four-way valve 17a → compressor 11b.

[0054] In cooling operation, the outdoor heat exchanger 15a of the first outdoor unit 2a and the outdoor heat exchanger 15b of the second outdoor unit 2b function as radiators, and the indoor heat exchanger 12a of the first indoor unit 3a and the indoor heat exchanger 12b of the second indoor unit 3b function as condensers. Then, the room in which the indoor unit 3a is installed and the room in which the indoor unit 3b is installed are cooled.

[0055] 9, the controller 110 is a control unit including a processor 120 and a memory 130, and the memory 130 stores a program 141 for controlling the refrigeration cycle apparatus 100 and control data 142 including data for determining whether the disproportionation is required. The controller 110 is connected to the refrigerant temperature sensor 20a, the refrigerant pressure sensor 21a, the human sensor 23a, the outdoor air temperature sensor 22a, the indoor temperature sensor 24a, the refrigerant temperature sensor 20b, the refrigerant pressure sensor 21b, the human sensor 23b, and the indoor temperature sensor 24b. The controller 110 receives detection signals from the refrigerant temperature sensor 20a, the refrigerant pressure sensor 21a, the human sensor 23a, the outdoor air temperature sensor 22a, the indoor temperature sensor 24a, the refrigerant temperature sensor 20b, the refrigerant pressure sensor 21b, the human sensor 23b, and the indoor temperature sensor 24b.

[0056] The controller 110 is connected to the compressor 11a, the outdoor expansion valve 14a, the four-way valve 17a, the outdoor fan 16a, the indoor fan 13a, the indoor expansion valve 18a, the compressor 11b, the outdoor expansion valve 14b, the four-way valve 17b, the outdoor fan 16b, the indoor fan 13b, and the indoor expansion valve 18b. The operation of the compressor 11a, the outdoor expansion valve 14a, the four-way valve 17a, the outdoor fan 16a, the indoor fan 13a, the indoor expansion valve 18a, the compressor 11b, the outdoor expansion valve 14b, the four-way valve 17b, the outdoor fan 16b, the indoor fan 13b, and the indoor expansion valve 18b is controlled by a control signal output from the controller 110.

[0057] The processor 120 reads and executes the program 131 to function as a refrigerant state recognition unit 121 and a control unit 122. The refrigerant state recognition unit 121 recognizes the state of the refrigerant discharged from the compressor 11a of the first outdoor unit 2a based on the temperature detected by the refrigerant temperature sensor 20a and the temperature detected by the refrigerant pressure sensor 21a of the first outdoor unit 2a, similar to the refrigerant state recognition unit 51 of the above-described first embodiment. In addition, the refrigerant state recognition unit 121 recognizes the state of the refrigerant discharged from the compressor 11b of the second outdoor unit 2b based on the temperature detected by the refrigerant temperature sensor 20b and the pressure detected by the refrigerant pressure sensor 21b of the second outdoor unit 2a.

[0058] The control unit 122 executes the heating operation described above with reference to Fig. 7 and the cooling operation described above with reference to Fig. 8. When executing the heating operation and when executing the cooling operation, the control unit 122 determines the outdoor units (first outdoor unit 2a, second outdoor unit 2b) and indoor units (first indoor unit 3a, second indoor unit 3b) to be operated according to the operating conditions (set temperature, set air volume, air-conditioned area, etc.) set by the remote control 111.

[0059] In addition, the control unit 122 controls the rotation speed of the compressor 11a of the first outdoor unit 2a, the opening of the outdoor expansion valve 14a, and the rotation speed of the outdoor fan 16a, the rotation speed of the compressor 11b of the second outdoor unit 2b, the opening of the outdoor expansion valve 14b, and the rotation speed of the outdoor fan 16b, the rotation speed of the compressor 11b of the second outdoor unit 2b, the rotation speed of the indoor fan 13a and the indoor expansion valve 18a of the first indoor unit 3a, and the rotation speed of the indoor fan 13b and the opening of the indoor expansion valve 18b of the second indoor unit 3b, based on the refrigerant temperature detected by the refrigerant temperature sensor 20a, the refrigerant pressure detected by the refrigerant pressure sensor 21a, the refrigerant temperature detected by the refrigerant temperature sensor 20b, the refrigerant pressure detected by the refrigerant pressure sensor 21b, the outdoor air temperature detected by the outdoor air temperature sensor 22a, the indoor temperature detected by the indoor temperature sensor 24a, and the indoor temperature detected by the indoor temperature sensor 24b, etc., in accordance with the operating conditions set by the remote control 111.

[0060] [2-2. Disproportionation suppression treatment] The control unit 122 monitors the state of the refrigerant discharged from the compressor 11a of the first outdoor unit 2a and the state of the refrigerant discharged from the compressor 11b of the second outdoor unit 2b, which are recognized by the refrigerant state recognition unit 121, during the execution of the heating operation and the execution of the cooling operation. Then, when the state of the refrigerant becomes the second disproportionation suppression necessary state, the control unit 52 executes the disproportionation suppression process of switching to the refrigerant recovery operation and recovering the refrigerant. The second disproportionation suppression necessary state may be the same as the first disproportionation suppression necessary state described above with reference to Fig. 5, or may be set to a state different from the first disproportionation suppression necessary state by slightly shifting the corresponding judgment curve in Fig. 5 to the AR1 (region where disproportionation occurs) side or the AR2 (region where disproportionation does not occur) side.

[0061] The procedure for executing the disproportionation suppression process will be described below with reference to the flowcharts shown in Figs. 10 and 11. The control unit 122 executes the process according to the flowcharts shown in Figs. 10 and 11 during heating operation and cooling operation. Steps S20 and S21 in Fig. 10 are processes performed by the refrigerant state recognition unit 121. In step S20, the refrigerant state recognition unit 121 recognizes the state of the refrigerant in the first outdoor unit 2a (the state of the refrigerant discharged from the compressor 11a) based on the temperature detected by the refrigerant temperature sensor 20a and the pressure detected by the refrigerant pressure sensor 21a of the first outdoor unit 2a. In the next step S21, the refrigerant state recognition unit 121 recognizes the state of the refrigerant in the second outdoor unit 2b (the state of the refrigerant discharged from the compressor 11b) based on the temperature detected by the refrigerant temperature sensor 20b and the pressure detected by the refrigerant pressure sensor 21b of the second outdoor unit 2b.

[0062] The subsequent steps S22 to S25, S30, S31, and S40 in Fig. 10 are processes performed by the control unit 122. In step S22, the control unit 122 judges whether the state of the refrigerant in the first outdoor unit 2a or the state of the refrigerant in the second outdoor unit 2b recognized by the refrigerant state recognition unit 121 is a state requiring a second disproportionation response. If the state of the first outdoor unit 2a or the state of the second outdoor unit 2b is a state requiring a second disproportionation response, the control unit 122 advances the process to step S23, and if neither the state of the first outdoor unit 2a nor the state of the second outdoor unit 2b is a state requiring a second disproportionation response, the control unit 122 advances the process to step S20.

[0063] Step S23 and FIG. 11 show the process of the refrigerant recovery operation in which the refrigerant is recovered into the refrigerant pipes 109 of the first indoor unit 3a and the second indoor unit 3b. In step S23, the control unit 122 sets the four-way valve 17a of the first outdoor unit 2a and the four-way valve 17b of the second outdoor unit 2b to the first flow state. In the next step S24 in FIG. 11, the control unit 122 judges whether or not the refrigerant of the first outdoor unit 2a is in a state requiring the second disproportionation response. Then, the control unit 122 advances the process to step S30 when the refrigerant of the first outdoor unit 2a is in a state requiring the second disproportionation response, and advances the process to step S25 when the refrigerant of the first outdoor unit 2a is not in a state requiring the second disproportionation response.

[0064] In step S30, the control unit 122 judges whether or not the refrigerant in the second outdoor unit 2b is in a state requiring the second disproportionation response. If the refrigerant in the second outdoor unit 2b is in a state requiring the second disproportionation response, the control unit 122 advances the process to step S40, and if the refrigerant in the second outdoor unit 2b is not in a state requiring the second disproportionation response, the control unit 122 advances the process to step S31.

[0065] Step S31 is a process of a refrigerant recovery operation (corresponding to the second refrigerant recovery operation of the present disclosure) corresponding to a case where the refrigerant in the first outdoor unit 2a is in the second disproportionation response necessary state and the refrigerant in the second outdoor unit 2b is not in the second disproportionation response necessary state. In step S31, the control unit 122 executes the following process. The outdoor expansion valve 14a of the first outdoor unit 2a is closed, and the outdoor expansion valve 14b of the second outdoor unit 2b is opened. The indoor expansion valve 18a of the first indoor unit 3a and the indoor expansion valve 18b of the second indoor unit 3b are opened. The indoor fan 13a of the first indoor unit 3a and the indoor fan 13b of the second indoor unit 3b are operated. The outdoor fan 16a of the first outdoor unit 2a and the outdoor fan 16b of the second outdoor unit 2b are operated. The compressor 11b of the second outdoor unit 2b is stopped, and the compressor 11a of the first outdoor unit 2a is operated.

[0066] As a result, as shown by the dashed arrows in Figure 12, the refrigerant discharged from the compressor 11a of the first outdoor unit 2a circulates through the compressor 11a → four-way valve 17a → the indoor heat exchanger 12a and the indoor expansion valve 18a of the first indoor unit 3a and the indoor heat exchanger 12b and the indoor expansion valve 18b of the second indoor unit 3b → the outdoor expansion valve 14b of the second outdoor unit 2b → the outdoor heat exchanger 15b of the second outdoor unit 2b → the four-way valve 17a of the second outdoor unit 2b → the compressor 11b of the second outdoor unit 2b, and is recovered and stored in the refrigerant piping 109 of the first indoor unit 3a, the second indoor unit 3b, and the second outdoor unit 2b. In this case, the refrigerant discharged from the compressor 11a of the first outdoor unit 2a is cooled and liquefied while flowing through the indoor heat exchanger 12a of the first indoor unit 3a, the indoor heat exchanger 12b of the second indoor unit 3b, and the outdoor heat exchanger 15b of the second outdoor unit 2b, and thus the amount of refrigerant recovered can be increased.

[0067] Step S25 is a process of a refrigerant recovery operation (corresponding to the second refrigerant recovery operation of the present disclosure) corresponding to a case where the refrigerant in the second outdoor unit 2b is in the second disproportionation response necessary state and the refrigerant in the first outdoor unit 2a is not in the second disproportionation response necessary state. In step S25, the control unit 122 executes the following process. The outdoor expansion valve 14b of the second outdoor unit 2b is closed, and the outdoor expansion valve 14a of the first outdoor unit 2a is opened. The indoor expansion valve 18a of the first indoor unit 3a and the indoor expansion valve 18b of the second indoor unit 3b are opened. The indoor fan 13a of the first indoor unit 3a and the indoor fan 13b of the second indoor unit 3b are operated. The outdoor fan 16a of the first outdoor unit 2a and the outdoor fan 16b of the second outdoor unit 2b are operated. The compressor 11a of the first outdoor unit 2a is stopped, and the compressor 11b of the second outdoor unit 2b is operated.

[0068] As a result, the refrigerant discharged from the compressor 11b of the second outdoor unit 2b circulates via the compressor 11b → four-way valve 17b → the indoor heat exchanger 12a and indoor expansion valve 18a of the first indoor unit 3a and the indoor heat exchanger 12b and indoor expansion valve 18b of the second indoor unit 3b → the outdoor expansion valve 14a of the first outdoor unit 2a → the outdoor heat exchanger 15a of the first outdoor unit 2a → the four-way valve 17a of the first outdoor unit 2a → the compressor 11a of the first outdoor unit 2a, and is recovered and stored in the refrigerant piping 109 of the first indoor unit 3a, the second indoor unit 3b, and the first outdoor unit 2a. In this case, the refrigerant discharged from the compressor 11b of the second outdoor unit 2b is cooled and liquefied while flowing through the indoor heat exchanger 12a of the first indoor unit 3a, the indoor heat exchanger 12b of the second indoor unit 3b, and the outdoor heat exchanger 15a of the first outdoor unit 2a, thereby increasing the amount of refrigerant recovered.

[0069] Step S40 is a process of a refrigerant recovery operation corresponding to a case where the refrigerant in the first outdoor unit 2a is in a state requiring the second disproportionation response and the refrigerant in the second outdoor unit 2b is also in a state requiring the second disproportionation response. In step S40, the control unit 122 executes the following process. The outdoor expansion valve 14a of the first outdoor unit 2a and the outdoor expansion valve 14b of the second outdoor unit 2b are closed. The indoor expansion valve 18a of the first indoor unit 3a and the indoor expansion valve 18b of the second indoor unit 3b are opened. The indoor fan 13a of the first indoor unit 3a and the indoor fan 13b of the second indoor unit 3b are operated. The outdoor fan 16a of the first outdoor unit 2a and the outdoor fan 16b of the second outdoor unit 2b are operated. The compressor 11a of the first outdoor unit 2a and the compressor 11b of the second outdoor unit 2b are operated.

[0070] As a result, the refrigerant discharged from the compressor 11a of the first outdoor unit 2a flows through the compressor 11a → four-way valve 17a → indoor heat exchanger 12a and indoor expansion valve 18a of the first indoor unit 2a and indoor heat exchanger 12b and indoor expansion valve 18b of the second indoor unit 3b, and is stored in the refrigerant pipes 109 of the first indoor unit 3a and the second indoor unit 3b. Also, the refrigerant discharged from the compressor 11b of the second outdoor unit 2b flows through the compressor 11b → four-way valve 17a → indoor heat exchanger 12a and indoor expansion valve 18a of the first indoor unit 3a and indoor heat exchanger 12b and indoor expansion valve 18b of the second indoor unit 3b, and is stored in the refrigerant pipes 109 of the first indoor unit 3a and the second indoor unit 3b.

[0071] In this case, the refrigerant discharged from the compressor 11a of the first outdoor unit 2a and the refrigerant discharged from the compressor 11b of the second outdoor unit 2b are cooled by the indoor heat exchanger 12a of the first indoor unit 3a or the indoor heat exchanger 12b of the second indoor unit 3b, promoting liquefaction of the refrigerant, thereby increasing the amount of refrigerant recovered.

[0072] [2-3. Effects, etc.] As described above, in the present embodiment, when the refrigerant becomes a state requiring disproportionation response in only one of the two outdoor units 2a, 2b, as shown in FIG. 12, the refrigeration cycle apparatus 100 executes a refrigerant recovery operation in which the compressor 11b of the second outdoor unit 2b that is not in a state requiring disproportionation response is stopped, the outdoor expansion valve 14a of the first outdoor unit 2a that is in a state requiring disproportionation response is closed, and the compressor 11a of the first outdoor unit 2a is operated. As a result, the refrigerant from the first outdoor unit 2a, which has reached a state requiring disproportionation response, can be stored in the refrigerant piping 109 of the second outdoor unit 2b in addition to being stored in the first indoor unit 3a and the second indoor unit 3b, thereby further increasing the amount of refrigerant recovered.

[0073] (Other embodiments) As described above, the above embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made.

[0074] In the above-mentioned embodiment 1, a process is performed in which the destination of the refrigerant recovery is switched between the refrigerant piping 19 of the indoor unit 3 and the refrigerant piping 19 of the outdoor unit 2 depending on whether the outdoor air temperature is below a predetermined temperature. However, this process may not be performed and the destination of the refrigerant recovery may be fixed to the refrigerant piping 19 of the indoor unit 3 or the outdoor unit 2.

[0075] In the above-mentioned second embodiment, the control unit 122 may recognize the presence or absence of people in each room in which the first indoor unit 3a and the second indoor unit 3b are installed, detected by the human presence sensors 23a, 23a, and operate only the indoor units installed in the rooms in which no people are present to perform the refrigerant recovery operation. For example, when it is recognized that there is a person in the room in which the first indoor unit 3a is installed and that there is no person in the room in which the second indoor unit 3b is installed, the control unit 122 operates the indoor fan 13b of the second indoor unit 3b while stopping the indoor fan 13a of the first indoor unit 3a, and performs the refrigerant recovery operation. This makes it possible to prevent the warm air sent out by the operation of the indoor fan of the first indoor unit 3a from causing discomfort or strangeness to the person in the room in which the first indoor unit 3a is installed.

[0076] In the above-mentioned second embodiment, a refrigeration cycle apparatus 100 having two outdoor units 2a, 2b and two indoor units 3a, 3b is exemplified, but the technology disclosed in this application can also be applied to a refrigeration cycle apparatus having three or more outdoor units and a refrigeration cycle apparatus having three or more indoor units. In a refrigeration cycle apparatus having three or more outdoor units, when it is recognized that the refrigerant in one outdoor unit (corresponding to the first outdoor unit in the present disclosure) has reached a state requiring a disproportionation response, a refrigerant recovery operation is executed to cause at least one other outdoor unit (corresponding to the second outdoor unit in the present disclosure) to recover the refrigerant.

[0077] In the above-mentioned second embodiment, similarly to the above-mentioned first embodiment, when the outdoor air temperature detected by the outdoor air temperature sensor 22a is higher than the indoor temperature detected by the indoor temperature sensor 24a or the indoor temperature sensor 24b, the refrigerant may be recovered in the refrigerant pipe 109 on the first indoor unit 3a and the second indoor unit 3b side (refrigerant recovery by the heating cycle), and when the outdoor air temperature is equal to or lower than the indoor temperature, the refrigerant may be recovered in the refrigerant pipe 109 on the first outdoor unit 2a or the second outdoor unit 2b side (refrigerant recovery by the cooling cycle). For example, when the outdoor air temperature is equal to or lower than the indoor temperature and the refrigerant in the first outdoor unit 2a is in a state requiring disproportionation, the four-way valve 17a of the first outdoor unit 2a is set to the second flow state, the outdoor expansion valve 14a is closed, and the outdoor fan 16a and the compressor 11a are operated to execute a refrigerant recovery operation in which the refrigerant is recovered in the refrigerant pipe 109 of the first outdoor unit 2a.

[0078] The controller in the present disclosure may be any controller capable of controlling the device in the present disclosure. When expressing the subject matter of the invention, the device in the present disclosure may be controlled by a control means, a control unit, or similar terms in addition to the controller. The controller can be realized in various forms. For example, a processor may be used as the controller. If a processor is used as the controller, various processes can be executed by loading a program from a storage medium storing the program into the processor and executing the program by the processor. Therefore, the process contents can be changed by changing the program stored in the storage medium, so that the degree of freedom in changing the control contents can be increased. Examples of the processor include a CPU (Central Processing Unit) and an MPU (Micro-Processing Unit). Examples of the storage medium include a hard disk, a flash memory, and an optical disk. In addition, a wired logic in which the program cannot be rewritten may be used as the controller. Using a wired logic as the controller is effective in improving the processing speed. Examples of the wired logic include an ASIC (Application Specific Integrated Circuit). In addition, the controller may be realized by combining a processor and a wired logic. If the controller is realized by combining a processor and wired logic, it is possible to increase the degree of freedom of software design and improve the processing speed. In addition, the controller and a circuit having a function different from that of the controller may be configured with a single semiconductor element. An example of a circuit having a different function is an A / D-D / A conversion circuit. In addition, the controller may be configured with a single semiconductor element or multiple semiconductor elements. When configured with multiple semiconductor elements, each control described in the claims may be realized with different semiconductor elements. Furthermore, the controller may be configured with a configuration including a semiconductor element and a passive component such as a resistor or a capacitor.

[0079] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, and the like can be made within the scope of the claims or their equivalents.

[0080] (Additional Note) The above description of the embodiments discloses the following techniques.

[0081] a refrigerant temperature sensor that detects a temperature of the refrigerant discharged from the compressor; a refrigerant pressure sensor that detects the pressure of the refrigerant discharged from the compressor; a refrigerant state recognition unit that recognizes a state of the refrigerant discharged from the compressor based on the temperature detected by the refrigerant temperature sensor and the pressure detected by the refrigerant pressure sensor; and a control unit that performs a refrigerant circulation operation to operate the compressor with the on-off valve open, and when a state of the refrigerant recognized by the refrigerant state recognition unit reaches a predetermined first disproportionation suppression required state during the refrigerant circulation operation, terminates the refrigerant circulation operation, and performs a refrigerant recovery operation to operate the compressor and the first blower fan with the on-off valve closed. With this configuration, when a state occurs in which a disproportionation reaction of the refrigerant may occur, a refrigerant recovery operation is performed in which the first blower fan is operated to cool the refrigerant in the radiator while recovering the refrigerant, thereby increasing the amount of refrigerant recovered, thereby suppressing the disproportionation reaction of the refrigerant.

[0082] (Technology 2) An indoor unit having an indoor heat exchanger functioning as the evaporator or the radiator, and an outdoor unit having an outdoor heat exchanger functioning as the evaporator or the radiator, the first blower fan cools the indoor heat exchanger, the compressor is provided in one connection path of the refrigeration circuit connecting the outdoor heat exchanger and the indoor heat exchanger, and the on-off valve is provided in the other connection path of the refrigeration circuit connecting the outdoor heat exchanger, and the refrigerant discharged from the compressor is passed through the indoor heat exchanger and circulated to the outdoor heat exchanger. the control unit executes a first refrigerant recovery operation as the refrigerant recovery operation in which the refrigerant discharged from the compressor flows with the outdoor heat exchanger as the upstream side and the indoor heat exchanger as the downstream side, and the control unit executes a first refrigerant recovery operation as the refrigerant recovery operation in which the refrigerant recovery operation is in the first flow state by the refrigerant flow direction switching unit and the on-off valve is closed, and the control unit executes a first refrigerant recovery operation as the refrigerant recovery operation in which the refrigerant recovery operation is in the first flow state and the on-off valve is closed, With this configuration, when a state occurs in which a disproportionation reaction of the refrigerant is likely to occur, the refrigerant can be recovered in the refrigerant circuit of the indoor unit, thereby suppressing the disproportionation reaction of the refrigerant.

[0083] (Technology 3) A refrigeration cycle apparatus according to Technology 2, comprising an outdoor air temperature sensor that detects an outdoor air temperature, and an indoor temperature sensor that detects the temperature of a room in which the indoor heat exchanger is installed, wherein the control unit, during execution of the refrigerant circulation operation, executes the first refrigerant recovery operation when the state of the refrigerant recognized by the refrigerant state recognition unit becomes the first disproportionation suppression necessary state and the temperature detected by the outdoor air temperature sensor is higher than the temperature detected by the indoor temperature sensor. With this configuration, the refrigerant is recovered to the indoor heat exchanger side, where the refrigerant is easier to condense because its temperature is lower, and where the effect of lowering the refrigerant pressure and temperature is greater, thereby enhancing the effect of avoiding disproportionation reactions of the refrigerant.

[0084] (Technology 4) A cooling system includes an indoor unit having an indoor heat exchanger functioning as the radiator, an outdoor heat exchanger functioning as the evaporator, a first outdoor unit and a second outdoor unit having the compressor, the on-off valve, the refrigerant temperature sensor, the refrigerant pressure sensor, and a second blower fan that cools the outdoor heat exchanger, wherein the refrigerant state recognition unit recognizes a state of the refrigerant discharged from the compressor of the first outdoor unit based on a temperature detected by the refrigerant temperature sensor of the first outdoor unit and a pressure detected by the refrigerant pressure sensor of the first outdoor unit, and recognizes a state of the refrigerant discharged from the compressor of the second outdoor unit based on the temperature detected by the refrigerant temperature sensor of the second outdoor unit and the pressure detected by the refrigerant pressure sensor of the second outdoor unit, and the control unit recognizes the state of the refrigerant discharged from the compressor of the first outdoor unit and the pressure detected by the refrigerant pressure sensor of the second outdoor unit. the refrigerant circulation operation is performed by controlling operation of an on-off valve of the first outdoor unit, and the compressor and the on-off valve of the second outdoor unit, and when a state of the refrigerant discharged from the compressor of the first outdoor unit recognized by the refrigerant state recognition unit during the refrigerant circulation operation becomes a predetermined second disproportionation suppression required state and the state of the refrigerant discharged from the compressor of the second outdoor unit recognized by the refrigerant state recognition unit is not the second disproportionation suppression required state, the refrigerant circulation operation is terminated and a second refrigerant recovery operation is performed as the refrigerant recovery operation, in which the compressor of the first outdoor unit is operated with the on-off valve of the first outdoor unit closed and the compressor of the second outdoor unit is stopped, and the first blower fan and the second blower fan of the second outdoor unit are operated. With this configuration, in a refrigeration cycle device equipped with a first outdoor unit and a second outdoor unit, when a state occurs in which disproportionation of the refrigerant may occur in the first outdoor unit, the second refrigerant recovery operation is performed to recover the refrigerant in the refrigerant circuits of the indoor unit and the second outdoor unit, thereby further increasing the amount of refrigerant recovered and suppressing disproportionation of the refrigerant. [Industrial Applicability]

[0085] INDUSTRIAL APPLICABILITY The present disclosure is applicable to applications in which a refrigeration cycle device uses a refrigerant containing a fluorocarbon hydrogen having the property of causing a disproportionation reaction, and the disproportionation reaction of the refrigerant occurring in the refrigeration circuit is suppressed by increasing the amount of refrigerant recovered without providing a receiver for recovering the refrigerant. [Explanation of symbols]

[0086] 1 Refrigeration cycle equipment 2 Outdoor unit 3 Indoor unit 5. Controller 6 Remote Control 10 Refrigeration circuit 11 Compressor 12 Indoor heat exchanger 13 Indoor fan 14 Outdoor expansion valve 15 Outdoor heat exchanger 16 Outdoor fan 17 Four-way valve 19 Refrigerant piping 20 Refrigerant temperature sensor 21 Refrigerant pressure sensor 22 Outside air temperature sensor 24 Indoor temperature sensor 50 processors 51 Refrigerant status recognition unit 52 Control section 60 Memory 61 Programs 62 Control Data 100 Refrigeration cycle device 101 Refrigeration circuit 109 Refrigerant piping 111 Remote Control 2a 1st outdoor unit 2b 2nd outdoor unit 3a 1st indoor unit 3b 2nd indoor unit 11a, 11b Compressor 12a,12b Indoor heat exchanger 13,13b Indoor fan 14a, 14b Outdoor expansion valve 15a,15b Outdoor heat exchanger 16a, 16b Outdoor fan 17a, 17b Four-way valve 18a, 18b Indoor expansion valve 20a, 20b Refrigerant temperature sensor 21a, 21b Refrigerant pressure sensor 22a Outside air temperature sensor 23a, 23b Human presence sensor 24a, 24b Indoor temperature sensor 110 Controller 120 processors 121 Refrigerant status recognition unit 122 Control section 130 Memory 131 Programs 132 Control Data

Claims

1. A refrigeration cycle device including a refrigeration circuit in which a refrigerant containing a hydrogen fluorocarbon having a property of causing a disproportionation reaction is sealed, the refrigeration cycle device being configured by connecting a compressor, a radiator, an on-off valve, and an evaporator in a ring shape by refrigerant piping, A first blower fan that blows air to the radiator; a refrigerant temperature sensor that detects the temperature of the refrigerant discharged from the compressor; a refrigerant pressure sensor that detects the pressure of the refrigerant discharged from the compressor; a refrigerant state recognition unit that recognizes a state of the refrigerant discharged from the compressor based on the temperature detected by the refrigerant temperature sensor and the pressure detected by the refrigerant pressure sensor; a control unit that executes a refrigerant circulation operation in which the compressor is operated with the on-off valve open, and when a state of the refrigerant recognized by the refrigerant state recognition unit becomes a predetermined first disproportionation suppression necessary state during the execution of the refrigerant circulation operation, ends the refrigerant circulation operation and executes a refrigerant recovery operation in which the compressor and the first blower fan are operated with the on-off valve closed; A refrigeration cycle device comprising:

2. an indoor unit having an indoor heat exchanger that functions as the evaporator or the radiator; an outdoor unit having an outdoor heat exchanger that functions as the evaporator or the radiator; The first blower fan cools the indoor heat exchanger, the compressor is provided in one connection path of the refrigeration circuit that connects the outdoor heat exchanger and the indoor heat exchanger, and the on-off valve is provided in the other connection path of the refrigeration circuit that connects the outdoor heat exchanger, a refrigerant flow direction switching unit that switches between a first flow state in which the refrigerant discharged from the compressor flows with the indoor heat exchanger on the upstream side and the outdoor heat exchanger on the downstream side, and a second flow state in which the refrigerant discharged from the compressor flows with the outdoor heat exchanger on the upstream side and the indoor heat exchanger on the downstream side, The control unit executes, as the refrigerant recovery operation, a first refrigerant recovery operation in which the refrigerant flow direction switching unit sets the refrigerant flow state to the first flow state, and the on-off valve is closed, and the compressor and the first blower fan are operated. The refrigeration cycle device according to claim 1.

3. An outside air temperature sensor for detecting an outside air temperature; an indoor temperature sensor for detecting the temperature of a room in which the indoor heat exchanger is installed; The control unit executes the first refrigerant recovery operation when the state of the refrigerant recognized by the refrigerant state recognition unit becomes the first disproportionation suppression necessary state during the execution of the refrigerant circulation operation and the temperature detected by the outside air temperature sensor is higher than the temperature detected by the indoor temperature sensor. The refrigeration cycle device according to claim 2.

4. an indoor unit having an indoor heat exchanger that functions as the radiator; a first outdoor unit and a second outdoor unit each having an outdoor heat exchanger functioning as the evaporator, the compressor, the on-off valve, the refrigerant temperature sensor, the refrigerant pressure sensor, and a second blower fan that blows air to the outdoor heat exchanger, the refrigerant state recognition unit recognizes a state of the refrigerant discharged from the compressor of the first outdoor unit based on a temperature detected by the refrigerant temperature sensor of the first outdoor unit and a pressure detected by the refrigerant pressure sensor of the first outdoor unit, and recognizes a state of the refrigerant discharged from the compressor of the second outdoor unit based on a temperature detected by the refrigerant temperature sensor of the second outdoor unit and a pressure detected by the refrigerant pressure sensor of the second outdoor unit; The control unit controls operation of the compressor and the on-off valve of the first outdoor unit, and the compressor and the on-off valve of the second outdoor unit, to perform the refrigerant circulation operation, and when a state of the refrigerant discharged from the compressor of the first outdoor unit recognized by the refrigerant state recognition unit during the execution of the refrigerant circulation operation becomes a predetermined second disproportionation suppression necessary state and a state of the refrigerant discharged from the compressor of the second outdoor unit recognized by the refrigerant state recognition unit is not the second disproportionation suppression necessary state, the control unit terminates the refrigerant circulation operation and performs a second refrigerant recovery operation as the refrigerant recovery operation, in which the compressor of the first outdoor unit is operated with the on-off valve of the first outdoor unit closed, the compressor of the second outdoor unit is stopped, and the first blower fan and the second blower fan of the second outdoor unit are operated. The refrigeration cycle device according to claim 1.

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