Refrigeration device

Abstract

To suppress disproportionation reaction in a refrigeration device.SOLUTION: A refrigeration device (90) includes casings (105, 205), refrigerant circuits (60), power supply units (45, 46), ground wires (51, 95) and ground resistors (55, 94). The refrigerant circuit (60) circulates a refrigerant (65) that may cause disproportionation reaction. The power supply units (45, 46) receive electric power from a commercial power supply (47). The ground wires (51, 95) conduct the casing (105, 205) to an external ground surface (G). The ground resistors (55, 94) are conducted to the ground wires (51, 95) and have a resistance value of 0.1 Ω or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a refrigeration apparatus, and more particularly to a refrigeration apparatus having a refrigerant circuit that circulates a refrigerant capable of causing a disproportionation reaction. [Background technology]

[0002] The refrigeration device disclosed in Patent Document 1 (International Publication No. WO2018 / 169776) uses a refrigerant that is prone to a self-decomposition reaction known as a disproportionation reaction. Summary of the Invention [Problem to be solved by the invention]

[0003] There is a possibility that disproportionation reactions in refrigeration equipment can be suppressed by reducing discharges inside compressors, etc. [Means for solving the problem]

[0004] A refrigeration apparatus according to a first aspect includes a housing, a refrigerant circuit, a power supply unit, a ground wire, and a ground resistor. The refrigerant circuit circulates a refrigerant capable of causing a disproportionation reaction. The power supply unit receives power from a commercial power supply. The ground wire connects the housing to a ground outside the housing. The ground resistor is connected to the ground wire and has a resistance value of 0.1 Ω or more.

[0005] According to this configuration, when discharge energy that may cause a disproportionation reaction of the refrigerant is generated inside the refrigeration device, the discharge energy can be consumed by the ground resistor, thereby suppressing the disproportionation reaction of the refrigerant.

[0006] A refrigeration apparatus according to a second aspect is the refrigeration apparatus according to the first aspect, further comprising a compressor, the compressor having a compressor housing, and the ground wire being electrically connected to the compressor housing.

[0007] According to this configuration, the discharge energy that may induce a disproportionation reaction of the refrigerant inside the refrigeration device is propagated through the ground wire that is electrically connected to the compressor housing and is consumed by the ground resistor, thereby suppressing the disproportionation reaction of the refrigerant.

[0008] A refrigeration apparatus according to a third aspect is the refrigeration apparatus according to the first aspect, further comprising a utilization heat exchanger. The ground wire is electrically connected to the utilization heat exchanger.

[0009] According to this configuration, the discharge energy that may induce a disproportionation reaction of the refrigerant inside the refrigeration device is propagated through the ground wire that is electrically connected to the utilization heat exchanger, and is consumed by the ground resistor, thereby suppressing the disproportionation reaction of the refrigerant.

[0010] A refrigeration apparatus of a fourth aspect is the refrigeration apparatus of the first aspect, further including a compressor and a utilization heat exchanger. The compressor has a compressor housing. The ground resistor has a first ground resistor and a second ground resistor. The ground wire has a first ground wire and a second ground wire. The first ground wire is electrically connected to the first ground resistor and the compressor housing. The second ground wire is electrically connected to the second ground resistor and the utilization heat exchanger.

[0011] According to this configuration, when one of the first ground wire and the second ground wire is broken, the discharge energy is propagated to the other and consumed by the ground resistor, thereby more reliably suppressing the disproportionation reaction of the refrigerant, thereby improving the safety of the refrigeration device.

[0012] A refrigeration apparatus according to a fifth aspect is the refrigeration apparatus according to any one of the first aspect to the fourth aspect, in which the refrigerant contains 1,2-difluoroethylene (HFO-1132).

[0013] According to this configuration, the refrigerant contains HFO-1132. Therefore, the disproportionation reaction of HFO-1132, which is prone to cause disproportionation reaction, can be suppressed.

[0014] A refrigeration apparatus according to a sixth aspect is the refrigeration apparatus according to the fifth aspect, wherein the refrigerant further comprises 2,3,3,3-tetrafluoropropene (HFO-1234yf).

[0015] According to this configuration, since the refrigerant contains HFO-1134yf, the flammability of the refrigerant can be reduced.

[0016] A refrigeration apparatus according to a seventh aspect is the refrigeration apparatus according to the sixth aspect, wherein the resistance value of the ground resistor is R (Ω). The ratio of 1,2-difluoroethylene (HFO-1132) in the refrigerant is A (mass %). The discharge energy applied to the refrigerant is E (J). The pressure when the refrigerant is used is P (MPa). Any one of the first condition, the second condition, and the third condition is satisfied. The first condition is R≧0.1 (Ω), E≦1000 (J), A≦32 (mass %), and P≦6 (MPa). The second condition is R≧1.0 (Ω), E≦250 (J), A≦45 (mass %), and P≦2 (MPa). The third condition is R≧10.0 (Ω), E≦30 (J), A≦55 (mass %), and P≦1 (MPa).

[0017] With this configuration, the discharge energy generated inside the refrigeration device can be sufficiently consumed by the ground resistor, and therefore the disproportionation reaction can be suppressed in the refrigerant composition specified in "A" of the first to third conditions.

[0018] A refrigeration apparatus according to an eighth aspect is the refrigeration apparatus according to any one of the first aspect to the fourth aspect, wherein the ground resistor is physically connected to the ground wire.

[0019] According to this configuration, the ground resistor is physically connected to the ground wire and does not require any modification to the inside of the unit, so that the space inside the housing is not taken up. [Brief description of the drawings]

[0020] [Figure 1] 2 is a schematic diagram showing a refrigerant circuit 60 and an electrical system 40 of a refrigeration device 90. FIG. [Diagram 2] FIG. 2 is a schematic diagram showing an electrical system 40. [Diagram 3] FIG. 2 is a cross-sectional view of a compressor 11. [Figure 4] 2 is a schematic diagram of the structure of a heat source unit 10. FIG. [Diagram 5] FIG. 2 is a diagram showing discharge locations of the compressor 11. [Figure 6] This is a model that represents discharges in a compressor. [Figure 7] 1 is a graph showing the relationship between discharge time, discharge energy, and resistance value. [Figure 8] 4 is a graph showing the relationship between refrigerant composition, refrigerant pressure, and discharge energy. [Figure 9] 1 is a graph showing the first condition with dots. [Figure 10] 1 is a graph showing the first condition with dots. [Figure 11] 13 is a graph showing the second condition with dots. [Figure 12] 13 is a graph showing the second condition with dots. [Figure 13] 13 is a graph showing the third condition with dots. [Figure 14] 13 is a graph showing the third condition with dots. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] <Embodiment> (1) Overall structure FIG. 1 is a schematic diagram showing a refrigerant circuit 60 and an electrical system 40 of a refrigeration device 90 according to the present disclosure. The refrigeration device 90 may be configured as a product such as an air conditioner, a refrigerator, a water heater, or a floor heating device. The refrigeration device 90 has a heat source unit 10, a utilization unit 20, a connecting pipe group 30, and a cable 43. The refrigeration device 90 is installed on the premises IP. A commercial power source 47 supplies power to the refrigeration device 90. An outlet of the commercial power source 47 transmits power from a commercial power transformer X installed on the outside premises OP to the refrigeration device 90.

[0022] (2) Detailed configuration (2-1) Heat source unit 10 The heat source unit 10 is for generating cold or heat from a heat source such as outside air. The heat source unit 10 includes a heat source housing 105, a compressor 11, a four-way switching valve 12, a heat source heat exchanger 13, a heat source fan 14, a heat source expansion valve 15, an accumulator 16, a liquid shutoff valve 17, a gas shutoff valve 18, and internal pipes T1 to T7. The heat source unit 10 further includes a heat source control unit 19 and a heat source power supply unit 45 that constitute an electric system 40.

[0023] (2-1-1) Compressor 11 The compressor 11 is a device that compresses the refrigerant 65 in a low-pressure gas state to make it into a high-pressure gas state. The compressor 11 is disposed inside the heat source housing 105. The compressor 11 is provided with a suction pipe 112 for sucking the refrigerant 65, and a discharge pipe 111 for discharging the refrigerant 65. The structure of the compressor 11 will be described later.

[0024] (2-1-2) Four-way switching valve 12 The four-way switching valve 12 is a device that switches between a cold energy utilization operation in which cold energy is provided to the user and a hot energy utilization operation in which hot energy is provided to the user by switching the path of the refrigerant 65. Details will be described later in the description of the refrigerant circuit 60.

[0025] (2-1-3) Heat source heat exchanger 13 The heat source heat exchanger 13 is a device that exchanges heat between the refrigerant 65 and air. The heat source heat exchanger 13 functions as a condenser during cold heat utilization operation and as an evaporator during hot heat utilization operation. The heat source heat exchanger 13 may be a device that exchanges heat between a medium such as water and the refrigerant.

[0026] (2-1-4) Heat source fan 14 The heat source fan 14 generates an airflow to promote heat exchange in the heat source heat exchanger 13. The airflow generated by the heat source fan 14 moves the air outside the heat source housing 105, which functions as a heat source, to the inside of the heat source housing 105, and moves the air that has completed heat exchange with the refrigerant 65 in the heat source heat exchanger 13 to the outside of the heat source housing 105. The heat source fan 14 is driven by a heat source fan motor.

[0027] (2-1-5) Heat source expansion valve 15 The heat source expansion valve 15 is a mechanism for reducing the pressure of the refrigerant 65 in a high-pressure liquid state to a low-pressure gas-liquid two-phase state. Furthermore, the heat source expansion valve 15 can adjust the amount of the refrigerant 65 circulating.

[0028] (2-1-6) Accumulator 16 The accumulator 16 is a container that removes and stores components of the liquid refrigerant 65 that are mixed in the gas refrigerant 65.

[0029] (2-1-7) Liquid shutoff valve 17 and gas shutoff valve 18 The liquid shutoff valve 17 and the gas shutoff valve 18 are valves that are manually opened and closed by an installer of the refrigeration device 90, and are used to cut off the path of the refrigerant.

[0030] (2-1-8) Internal piping T1~T7 The internal pipes T1 to T7 are pipes that connect between components arranged inside the heat source housing 105. Specifically, the internal pipe T1 connects the discharge pipe 111 and the four-way switching valve 12. The internal pipe T2 connects the four-way switching valve 12 and the heat source heat exchanger 13. The internal pipe T3 connects the heat source heat exchanger 13 and the heat source expansion valve 15. The internal pipe T4 connects the heat source expansion valve 15 and the liquid stop valve 17. The internal pipe T5 connects the gas stop valve 18 and the four-way switching valve 12. The internal pipe T6 connects the four-way switching valve 12 and the accumulator 16. The internal pipe T7 connects the accumulator 16 and the suction pipe 112.

[0031] (2-1-9) Heat source control unit 19 and heat source power supply unit 45 The heat source control unit 19 reads the output of various sensors stored in the heat source unit 10 and controls various actuators. The heat source power supply unit 45 adjusts various power supply voltages required by the heat source unit 10. A supplementary explanation of these units will be given in the explanation of the electrical system 40.

[0032] (2-2) Usage unit 20 The utilization unit 20 is for providing cold or hot heat to a user. The utilization unit 20 has a utilization housing 205, a utilization heat exchanger 23, and a utilization fan 24. The utilization unit 20 further has a utilization control unit 29 and a utilization power supply unit 46 that constitute an electric system 40.

[0033] (2-2-1) Utilized heat exchanger 23 The utilization heat exchanger 23 is a device that exchanges heat between the refrigerant 65 and air. The utilization heat exchanger 23 functions as an evaporator during cold heat utilization operation, and functions as a condenser during hot heat utilization operation. The utilization heat exchanger 23 may be a device that exchanges heat between a medium such as water and the refrigerant. The utilization heat exchanger 23 is disposed inside the utilization housing 205.

[0034] (2-2-2) 24 fans in use The utilization fan 24 generates an air flow to promote heat exchange in the utilization heat exchanger 23. In addition, if the refrigeration device 90 is an air conditioner, the utilization fan 24 sends conditioned air to the user's location. If the refrigeration device 90 is a water heater, the utilization fan 24 may be in the form of a pump that transports hot water to the user's location. The utilization fan 24 is driven by a utilization fan motor.

[0035] (2-2-3) Usage control unit 29 and usage power supply unit 46 The utilization control unit 29 reads the output of various sensors stored in the utilization unit 20 and controls various actuators. The utilization power supply unit 46 adjusts various power supply voltages required by the utilization unit 20. A supplementary explanation of these units will be given in the explanation of the electrical system 40.

[0036] (2-3) Interconnecting piping group 30 The interconnection pipe group 30 is a pipe that connects the heat source unit 10 and the utilization unit 20. The interconnection pipe group 30 has a liquid interconnection pipe 31 and a gas interconnection pipe 32. The liquid interconnection pipe 31 connects the liquid stop valve 17 and the utilization heat exchanger 23. The gas interconnection pipe 32 connects the gas stop valve 18 and the utilization heat exchanger 23.

[0037] (2-4) Cable 43 The cable 43 constitutes a part of the electrical system 40. The cable 43 will be explained in more detail in the explanation of the electrical system 40.

[0038] (3) Refrigerant circuit 60 (3-1) Refrigerant 65 The refrigerant circuit 60 circulates a refrigerant 65 .

[0039] In the refrigerant circuit 60, the refrigerant 65 is compressed, releases heat or is condensed, reduced in pressure, absorbs heat or is evaporated, and then is compressed again. The refrigerant circuit 60 is composed of a heat source refrigerant circuit 61, a utilization refrigerant circuit 62, and a communication pipe group 30. The heat source refrigerant circuit 61 is composed of a part of the heat source unit 10. The heat source refrigerant circuit 61 includes, as main elements, a compressor 11, a four-way switching valve 12, a heat source heat exchanger 13, a heat source expansion valve 15, and internal pipes T1 to T7. The utilization refrigerant circuit 62 is composed of a part of the utilization unit 20. The utilization refrigerant circuit 62 includes a utilization heat exchanger 23.

[0040] The refrigerant 65 is of a type that can undergo disproportionation reactions.

[0041] The refrigerant 65 is a mixed refrigerant and contains the following components 1 and 2.

[0042] Component 1: 1,2-Difluoroethylene (HFO-1132) Component 2: 2,3,3,3-Tetrafluoropropene (HFO-1234yf) Of the two, component 1 is more strongly involved in the occurrence of the disproportionation reaction. The molecular formula of component 1 is as follows.

[0043] [ka]

[0044] Component 1 may be, for example, cis-1,2-difluoroethylene (HFO-1132(Z)). Alternatively, component 1 may be trans-1,2-difluoroethylene (HFO-1132(E)). Furthermore, component 1 may be trifluoroethylene (HFO-1123).

[0045] (3-2)Cold heat utilization operation With reference to FIG. 1, the operation when a user utilizes cold energy will be described. In this case, the four-way switching valve 12 realizes the connection shown by the solid line. The refrigerant 65 in a low-pressure gas state is compressed by the compressor 11. The refrigerant 65 in a high-pressure gas state is discharged from the discharge pipe 111. The refrigerant 65 in a high-pressure gas state is condensed in the heat source heat exchanger 13, and releases heat into the air in the process of becoming a high-pressure liquid state. Next, the refrigerant 65 in a high-pressure liquid state is decompressed by the heat source expansion valve 15 and becomes a low-pressure gas-liquid two-phase state. The refrigerant 65 in a low-pressure gas-liquid two-phase state is evaporated in the utilization heat exchanger 23, and takes heat from the air in the process of becoming a low-pressure gas state. This means that the refrigerant 65 provides cold energy to the user's environment. When the refrigerant 65 in a low-pressure gas state passes through the accumulator 16, a small amount of liquid refrigerant mixed in the refrigerant 65 in a low-pressure gas state is separated. Next, the refrigerant 65 in a low pressure gas state is sucked into the compressor 11 through the suction pipe 112 .

[0046] (3-3) Heat utilization operation With reference to FIG. 1, the operation when a user utilizes heat will be described. In this case, the four-way switching valve 12 realizes the connection shown by the broken line. The refrigerant 65 in a low-pressure gas state is compressed by the compressor 11. The refrigerant 65 in a high-pressure gas state is discharged from the discharge pipe 111. The refrigerant 65 in a high-pressure gas state is condensed in the utilization heat exchanger 23, and in the process of becoming a high-pressure liquid state, releases heat into the air. This means that the refrigerant 65 provides heat to the user's environment. Next, the refrigerant 65 in a high-pressure liquid state is decompressed by the heat source expansion valve 15 and becomes a low-pressure gas-liquid two-phase state. The refrigerant 65 in a low-pressure gas-liquid two-phase state is evaporated in the heat source heat exchanger 13, and in the process of becoming a low-pressure gas state, it takes heat from the air. When the refrigerant 65 in a low-pressure gas state passes through the accumulator 16, a small amount of liquid refrigerant mixed in the refrigerant 65 in a low-pressure gas state is separated. Next, the refrigerant 65 in a low pressure gas state is sucked into the compressor 11 through the suction pipe 112 .

[0047] (4) Electrical system 40 2 is a schematic diagram showing an electric system 40 of the refrigeration device 90. The electric system 40 has a utilization power supply unit 46, a utilization control unit 29, a heat source power supply unit 45, and a heat source control unit 19.

[0048] (4-1) Power supply unit 46 The utilization power supply unit 46 has a rectifier 461 and a regulator 462. The rectifier 461 rectifies the AC power received from the commercial power supply 47 to generate a DC power supply voltage V1 with respect to the ground potential GND. The power supply voltage V1 has a magnitude capable of driving various actuators including motors. The regulator 462 generates a power supply voltage V2 smaller than the power supply voltage V1. The power supply voltage V2 is used to drive a signal processing circuit including a processor.

[0049] (4-2) Usage control unit 29 The utilization control unit 29 receives the power supply voltage V1, the power supply voltage V2, and the ground potential GND from the utilization power supply unit 46, and generates control signals for driving various actuators including the utilization fan 24.

[0050] (4-3) Cable 43 The cable 43 connects the utilization unit 20 and the heat source unit 10, and constitutes part of the electrical system 40. The cable 43 accommodates a power line 41, a ground line 42, and a communication line 49. The power line 41 transmits a power supply voltage. The power line 41 includes a first power supply line 41a and a second power supply line 41b. The first power supply line 41a transmits a power supply voltage V1. The second power supply line 41b transmits a power supply voltage V2. The ground line 42 transmits a ground potential GND, which is a reference potential for the power supply voltage. The communication line 49 transmits a communication signal between the heat source control unit 19 and the utilization control unit 29.

[0051] (4-4) Heat source power supply unit 45 The heat source power supply unit 45 has capacitors 451 and 452 that smooth the power supply voltages V1 and V2 transmitted via the cable 43, respectively.

[0052] (4-5) Heat source control unit 19 The heat source control unit 19 receives supply voltages V1, V2, and ground potential GND from the heat source power supply unit 45, and generates control signals for driving various actuators including the compressor 11, the four-way switching valve 12, the heat source fan 14, and the heat source expansion valve 15. The heat source control unit 19 is connected to the utilization control unit 29 by a communication line 49. The communication line 49 is used for communication of various information such as commands, status, and data.

[0053] (5) Structure of Compressor 11 3 shows a cross section of the compressor 11. The compressor 11 includes a compressor housing 71, a motor 72, a crankshaft 73, a compression mechanism 74, and a terminal portion 75.

[0054] (5-1) Compressor housing 71 The compressor housing 71 is a container that houses the components of the compressor 11. Furthermore, the compressor housing 71 houses the refrigerant 65 and refrigeration oil. The compressor housing 71 has an upper portion 711, a cylindrical portion 712, and a lower portion 713 that are hermetically welded together, and has a structure that can withstand the high pressure of the refrigerant 65.

[0055] The compressor housing 71 is provided with the above-mentioned suction pipe 112 and discharge pipe 111. The suction pipe 112 is provided below the cylindrical portion 712. The discharge pipe 111 is provided in the upper portion 711.

[0056] (5-2) Motor 72 The motor 72 is a device that receives a supply of electric power and generates power for driving the compression mechanism 74. The motor 72 is provided above the cylindrical portion 712. The motor 72 has a stator 721 fixed to the compressor housing 71 and a rotor 725 that is rotatably installed.

[0057] Stator 721 includes stator core 722 made of laminated steel plates, insulator 723 made of resin, and coil 724. Coil 724 is a winding wound around stator core 722 and insulator 723. Coil 724 generates an AC magnetic field.

[0058] Rotor 725 has rotor core 726 made of laminated steel plates, and permanent magnets and end plates (not shown). The permanent magnets rotate the entire rotor 725 by interacting with the AC magnetic field generated by coils 724. The end plates prevent the permanent magnets installed in the cavities provided in rotor core 726 from falling out.

[0059] (5-3) Crankshaft 73 The crankshaft 73 transmits the rotational force generated by the motor 72 to the compression mechanism 74 .

[0060] (5-4) Compression mechanism 74 The compression mechanism 74 is provided below the cylindrical portion 712 and is connected to the suction pipe 112. The compression mechanism 74 has a cylinder 741, a piston 742, and a muffler 744. The cylinder and the piston 742 define a compression chamber 743. The piston 742 revolves due to the rotation of the crankshaft 73, and the volume of the compression chamber 743 varies. As a result, the refrigerant 65 in a low-pressure gas state sucked from the suction pipe 112 is compressed and becomes a high-pressure gas state. The refrigerant 65 in the high-pressure gas state has its pressure pulsation reduced by the muffler 744. This reduces noise. The refrigerant 65 that has left the muffler passes upward through gaps in the motor 72 (for example, the gap between the stator 721 and the rotor 725, the core cut provided between the stator 721 and the cylindrical portion 712, and the gap between the adjacent coils 724 in the stator 721, etc.), and is then discharged from the discharge pipe 111 to the outside of the compressor 11.

[0061] (5-5) Terminal section 75 The terminal unit 75 takes in electric power supplied from the outside into the compressor 11. The terminal unit 75 has a terminal pin 751, a terminal base 752, a lead wire 753, and a terminal guard 754. The terminal pin 751 is a terminal for connecting an external electric wire. The terminal base 752 is a member for standing the terminal pin 751 on the compressor housing 71. The lead wire 753 connects the terminal pin 751 to the coil 724 of the motor 72. The terminal guard 754 is provided on the surface of the compressor housing 71, and by surrounding the terminal pin 751, prevents damage to the terminal pin 751.

[0062] (5-6) Protection circuit A protection circuit interrupts the current if a short circuit occurs in the electrical circuit of the compressor 11. The protection circuit includes an inverter protection device and a non-inverter sine wave breaker.

[0063] The inverter protection device is mounted on the heat source control unit 19. The inverter protection device has a current detection means such as a shunt resistor. When a current value exceeding a threshold is detected in the inverter output current, the inverter protection device stops the inverter output current.

[0064] The non-inverter sine breaker is mounted on a distribution board in the commercial power source 47. The non-inverter sine breaker has a ZTC (zero-phase current transformer), a leakage current relay, and a circuit breaker. The non-inverter sine breaker stops the power supply from the commercial power source 47 to the refrigeration device 90 when a leakage current occurs.

[0065] (6) Ground path (6-1) Heat source unit 10 FIG. 4 is a schematic diagram of the structure of the heat source unit 10. As shown in FIG.

[0066] The heat source casing 105 is in communication with the liquid stop valve 17 and the gas stop valve 18. The liquid stop valve 17 and the gas stop valve 18 are in communication with a part of the four-way switching valve 12, a part of the accumulator 16, the compressor casing 71, a part of the heat source expansion valve 15, and the heat source heat exchanger 13 via internal piping T1 to T7.

[0067] The ground wire 51 is a conductor that connects the heat source housing 105 and the ground G, and has the function of guiding the discharge energy generated inside the heat source unit 10 to the ground G. A buried part 53 is buried in the ground G that grounds the heat source unit 10. The buried part 53 is connected to the liquid stop valve 17 by the ground wire 51. The ground wire 51 forms a ground path that connects the heat source housing 105 and the ground G.

[0068] A ground resistor 55 is connected to the ground wire 51. The ground resistor 55 consumes the electrical energy flowing through the ground wire 51 and converts it into thermal energy. The ground resistor 55 may be, for example, an electronic component that is physically connected to the ground wire 51, or may be a ground resistor.

[0069] The heat source power supply unit 45 and the heat source control unit 19 that constitute the electric system 40 are stored in an electric component box 48. As shown in Fig. 4, by appropriately installing the electric component box 48, a conductive path 59 is formed between the ground potential GND of the electric system 40 and the heat source housing 105. Due to the presence of the conductive path 59, the ground potential GND of the electric system 40 is also conductive with the ground wire 51 and the ground G.

[0070] (6-2) Usage unit 20 1, the utilization heat exchanger 23 is electrically connected to a ground wire 95 extending to the outside of the utilization housing 205. A ground resistor 94 is connected in series to the ground wire 95. The ground resistor 94 may be, for example, an electronic component physically connected to the ground wire 95, or may be a ground resistor.

[0071] The outlet of the commercial power supply 47 has a first power terminal 91, a second power terminal 92, and a ground terminal 93. The ground terminal 93 is electrically connected to a buried portion 96 buried in the ground. A ground wire 95 of the utilization unit 20 is connected to the ground terminal 93. The ground terminal 93 is connected to the utilization heat exchanger 23 via a ground resistor 94.

[0072] (7) Disproportionation reaction mechanism The applicants have discovered that a disproportionation reaction is induced when discharge energy is applied to the refrigerant 65. The disproportionation reaction is represented by the following chemical formula:

[0073] [ka]

[0074] As can be seen from this chemical formula, in the disproportionation reaction, the aforementioned component 1 (1,2-difluoroethylene, HFO-1132) in the refrigerant 65 is decomposed and heat is generated. The heat generation induces further decomposition of the unreacted refrigerant, causing a chain reaction of decomposition. If this occurs in the housing of the refrigeration device 90, a rapid pressure rise can occur in a short period of time.

[0075] (8) Discharge in compressor 11 5 shows discharge points S1, S2, and S3 where discharge is likely to occur inside the compressor 11. The discharge point S1 is between the terminal pin 751 and the compressor housing 71. The compressor housing 71 here includes the portion of the terminal base 752 that is electrically connected to the compressor housing 71 and the terminal guard 754. The discharge point S2 is between the lead wire 753 and the compressor housing 71. The discharge point S3 is between the coil 724 and the stator core 722. The stator core 722 is electrically connected to the compressor housing 71. Discharges that are relatively likely to occur at the discharge points S1 to S3 can induce a disproportionation reaction.

[0076] The discharge energy in the compressor can be calculated according to a model 80 shown in FIG. 6. The model 80 is a closed loop circuit in which a DC power supply 81, a resistor 82, and a movable contact 83 are connected in series. The potential difference between the terminals on both sides of the DC power supply 81 is the contact voltage E (V). The resistor 82 has a resistance value R (Ω). This resistor 82 in the model 80 is for simulating the earth resistor 55 or the earth resistor 94 in the refrigeration device 90. The movable contact 83 can set the discharge duration T (s) by changing the distance between the contacts. The magnitude of the current flowing through the movable contact 83 is the short-circuit current I (A). When the discharge duration is T (s), the discharge energy Dis.E (J) generated at the movable contact 83 can be calculated by the following formula.

[0077]

number

[0078] where the variables and constants are as follows: Dis.E(J): Discharge energy E(V): Power supply voltage of the circuit I(A): Short circuit current R(Ω): Resistance value T(s): Discharge duration Varc(V): Voltage between the contacts where the arc occurs Iarc(A): Short circuit current when arc occurs. It is the same value as I(A) mentioned above. Em: Parameter determined by contact material Im: Parameter determined by contact material

[0079] FIG. 7 is a graph in which the discharge energy Dis.E(J) is calculated using the above formula when the discharge duration T(s) and the resistance value R(Ω) are changed, and plotted on a logarithmic scale. The horizontal axis showing the discharge duration T(s) is indicated with the reference periods P1 to P3. The period P1 is the time interval from the start of discharge to the start of operation of the inverter protection device. During the period P1, the inverter protection device operates. This causes the compressor 11 to stop. During the period P2, the voltage supplied to the motor 72 becomes a square wave. The period P3 is the operation period of the non-inverter sine wave earth leakage breaker. After the period P3 has elapsed, the power supply to the refrigeration device 90 is stopped. The period P3 that is the latest from the start of discharge can bring about the longest discharge duration T(s). The end of period P3, 10 ms after the start of discharge, is considered to be the maximum discharge duration T (s).

[0080] (9) Presence or absence of disproportionation reaction 8 is a graph showing the disproportionation occurrence boundary line at each discharge energy Dis.E (J) when the content (mass%) of HFO-1132 in refrigerant 65 and pressure P (MPa) are changed. For example, when the discharge energy Dis.E (J) is 3 (J), the disproportionation reaction occurs in region A1 in the figure, but does not occur in region A2.

[0081] As examples of conditions under which the disproportionation reaction does not occur, the first to third conditions will be explained below.

[0082] (9-1) First condition The first condition is the shaded area shown in Figures 9 and 10. Here, Figures 9 and 10 are Figures 7 and 8 to which shaded areas and the like have been added, respectively.

[0083] The first condition is: R≧0.1(Ω),……Fig.9 E≦1000(J), ……Fig. 9, Fig. 10 A≦32 (mass%) and...Figure 10 P≦6(MPa),……Figure 10 It is.

[0084] (9-2) Second condition The second condition is the shaded area shown in Figures 11 and 12. Here, Figures 11 and 12 are Figures 7 and 8 to which shaded areas and the like have been added, respectively.

[0085] The second condition is: R≧1.0(Ω),……Fig.11 E≦250(J), ……Fig. 11, Fig. 12 A≦45 (mass%) and...Figure 12 P≦2(MPa),……Fig.12 It is.

[0086] (9-3) Third condition The third condition is the shaded areas shown in Figures 13 and 14. Here, Figures 13 and 14 are Figures 7 and 8 to which shaded areas and the like have been added, respectively.

[0087] The third condition is: R≧10.0(Ω),……Fig.13 E≦30(J), ……Fig. 13, Fig. 14 A≦55 (mass%) and...Figure 14 P≦1(MPa),……Figure 14 It is.

[0088] (10) Features (10-1) When discharge energy Dis.E(J) that may cause a disproportionation reaction of the refrigerant 65 is generated inside the refrigeration device 90, the discharge energy Dis.E(J) can be consumed by the ground resistor 55. Therefore, in the refrigeration device 90, the disproportionation reaction of the refrigerant 65 can be suppressed.

[0089] (10-2) Discharge energy that may induce a disproportionation reaction of the refrigerant 65 inside the refrigeration device 90 propagates through the ground wire 51 that is electrically connected to the compressor housing 71, and is consumed by the ground resistor 55. Therefore, the disproportionation reaction of the refrigerant 65 is suppressed.

[0090] (10-3) Discharge energy that may induce a disproportionation reaction of the refrigerant 65 inside the refrigeration device 90 propagates through the ground wire 95 that is electrically connected to the utilization heat exchanger 23, and is consumed by the ground resistor 94. Therefore, the disproportionation reaction of the refrigerant 65 is suppressed.

[0091] (10-4) When a break occurs in one of the two ground wires, the ground wire 51 and the ground wire 95, the discharge energy propagates to the other and is consumed by the ground resistor 55 or the ground resistor 94. Therefore, the disproportionation reaction of the refrigerant 65 is more reliably suppressed, and the safety of the refrigeration device 90 can be improved.

[0092] (10-5) Refrigerant 65 contains HFO-1132. Therefore, the disproportionation reaction of HFO-1132, which is prone to disproportionation, can be suppressed. Refrigerant 65 may further contain HFO-1134yf. Since refrigerant 65 contains HFO-1134yf, the flammability of refrigerant 65 can be reduced.

[0093] (10-6) The ground resistors 55, 94 can sufficiently consume the discharge energy generated inside the refrigeration device 90. Therefore, the disproportionation reaction can be suppressed in the refrigerant composition specified in "A" of the first to third conditions.

[0094] (10-7) The ground resistors 55, 94 are physically connected to the ground wires 51, 95 and do not require modification inside the housing, so they do not take up space inside the housing.

[0095] <Modifications of the above embodiment> (11) Variations (11-1) Variation A In the above embodiment, the ground wire 51 of the heat source unit 10 is provided with a ground resistor 55, and the ground wire 95 of the utilization unit 20 is also provided with a ground resistor 94. Alternatively, only one of the ground resistor 55 of the ground wire 51 or the ground resistor 94 of the ground wire 95 may be provided.

[0096] (11-2) Variation B It is not necessary to provide the conductive path 59 that connects the ground potential GND of the electric system 40 and the heat source housing 105. In other words, the ground potential GND may be insulated from the heat source housing 105.

[0097] (11-3) Variation C The configuration of the electrical system 40 is not limited to that described above. For example, the heat-source power supply unit 45 may have a regulator and generate the power supply voltage V2 by itself. The heat-source power supply unit 45 may also receive power from a commercial power supply 47. The number of power lines 41 is not limited to two, the first power line 41a and the second power line 41b, and may be one or three or more.

[0098] (11-4) Variation D The ground resistor 55 may be disposed inside the heat source housing 105. For example, the ground resistor 55 may be mounted on the circuit board of the electrical component box 48.

[0099] (11-5) Variation E The refrigeration device 90 in the above embodiment has a heat source unit 10 and a utilization unit 20 that are separate from each other. Alternatively, the refrigeration device 90 may be configured as a single unit in which the heat source unit 10 and the utilization unit 20 share the same housing.

[0100] <Conclusion> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure described in the claims. [Explanation of symbols]

[0101] 10: Heat source unit 11: Compressor 17: Liquid shutoff valve 18: Gas shutoff valve 19: Heat source control unit 20: Unit of use 29: Usage control unit 30: Interconnecting piping group 40: Electrical system 41: Power line 41a: 1st power line 41b: 2nd power line 42: Ground line 43: Cable 45: Heat source power supply unit (power supply unit) 46: Power supply unit used 47:Commercial power supply 48: Electrical equipment box 49: Communication line 51: Ground wire (1st ground wire) 53: Buried section 55: Grounding resistor (1st grounding resistor) 59: Conduction path 60: Refrigerant circuit 61: Heat source refrigerant circuit (refrigerant circuit) 62: Utilized refrigerant circuit (refrigerant circuit) 65: Refrigerant 71: Compressor housing 72: Motor 73: Crankshaft 74: Compression mechanism 75: Terminal section 90: Refrigeration equipment 94: Grounding resistor (second grounding resistor) 95: Ground wire (second ground wire) 105: Heat source housing (housing) 111:Discharge pipe 112:Suction pipe 711: Top 712: Cylindrical part 713: Lower part 721: Stator 722: Stator core 723: Insulator 724: Coil 725:Rotor 726: Rotor core 751: Terminal pin 752: Terminal Base 753: Lead wire 754: Terminal guard G: Ground GND: Ground potential E: Contact voltage I: Short circuit current T: Discharge duration A (mass%): Refrigerant composition ratio Dis.E(J): Discharge energy P(MPa): Pressure R(Ω):Resistance value [Prior art documents] [Patent documents]

[0102] [Patent Document 1] International Publication No. WO2018 / 169776

Claims

1. A housing (105; 205); a refrigerant circuit (60; 61; 62) for circulating a refrigerant (65) capable of causing a disproportionation reaction; a power supply unit (45; 46) receiving power from a commercial power supply (47); A ground wire (51; 95) for electrically connecting the housing to a ground (G) outside the housing; A ground resistor (55; 94) connected to the ground wire and having a resistance of 0.1 Ω or more; A refrigeration device (90).

2. a compressor (11) having a compressor housing (71), The ground wire (51) is electrically connected to the compressor housing.

2. The refrigeration system of claim 1.

3. A utilization heat exchanger (23), The ground wire (95) is in electrical communication with the utilization heat exchanger.

2. The refrigeration system of claim 1.

4. A compressor (11) having a compressor housing (71); A utilization heat exchanger (23); and The ground resistor is A first ground resistor (55); A second ground resistor (94); having The ground wire is a first grounding wire (51) that is electrically connected to the first grounding resistor and the compressor housing; a second grounding wire (95) that is connected to the second grounding resistor and the utilization heat exchanger; having 2. The refrigeration system of claim 1.

5. The refrigerant (65) contains 1,2-difluoroethylene (HFO-1132). A refrigeration system according to any one of claims 1 to 4.

6. The refrigerant (65) further comprises 2,3,3,3-tetrafluoropropene (HFO-1234yf).

6. The refrigeration system of claim 5.

7. The resistance value of the ground resistor (55; 94) is R (Ω), The ratio of the 1,2-difluoroethylene (HFO-1132) in the refrigerant (65) is A (mass%), The discharge energy applied to the refrigerant is Dis. E (J), The pressure of the refrigerant when it is used is P (MPa), Any one of the first condition, the second condition, and the third condition is satisfied; The first condition is: R≧0.1(Ω), E≦1000(J), A≦32 (mass%), and P≦6 (MPa); and The second condition is: R≧1.0(Ω), E≦250(J), A≦45 (mass%), and P≦2 (MPa), and The third condition is: R≧10.0(Ω), E≦30(J), A≦55 (mass%), and P≦1 (MPa), That is, 7. The refrigeration system of claim 6.

8. The ground resistor (55; 94) is physically connected to the ground line (51; 95). A refrigeration system according to any one of claims 1 to 4.

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