Refrigeration device

Abstract

A refrigeration device (90) is provided with housings (105, 205), a refrigerant circuit (60), power supply units (45, 46), ground wires (51, 95), and ground resistors (55, 94). The refrigerant circuit (60) circulates a refrigerant (65) capable of generating a disproportionation reaction. Power supply units (45, 46) receive power from a commercial power supply (47). Ground wires (51, 95) conduct the housings (105, 205) and an external ground (G). The ground resistors (55, 94) are electrically connected to the ground wires (51, 95), and have a resistance value of 0.1 Omega or more.

Description

Technical Field

[0001] This disclosure relates to refrigeration apparatuses, and more particularly to refrigeration apparatuses having a refrigerant circuit that allows a refrigerant to circulate in a manner that may cause a disproportionation reaction. Background Technology

[0002] The refrigeration device disclosed in Patent Document 1 (International Publication No. WO2018 / 168776) uses a refrigerant that is prone to undergoing a self-decomposition reaction known as disproportionation. Summary of the Invention

[0003] The problem that the invention aims to solve

[0004] By reducing the discharge inside the compressor, there is room to suppress the disproportionation reaction in the refrigeration unit.

[0005] Methods for solving problems

[0006] The first-concept refrigeration unit includes a housing, a refrigerant circuit, a power supply unit, a grounding wire, and a grounding resistor. The refrigerant circuit circulates the refrigerant, which may undergo a disproportionation reaction. The power supply unit receives power from a commercial power source. The grounding wire connects the housing to the external ground. The grounding resistor is connected to the grounding wire and has a resistance of 0.1Ω or higher.

[0007] According to this structure, if discharge energy is generated inside the refrigeration device that could potentially cause a refrigerant disproportionation reaction, this discharge energy can be dissipated through a grounding resistor. Therefore, the refrigerant disproportionation reaction can be suppressed.

[0008] The second viewpoint's refrigeration device, compared to the first viewpoint's refrigeration device, also includes a compressor. The compressor has a compressor housing. A grounding wire is connected to the compressor housing.

[0009] According to this structure, the discharge energy that could induce a refrigerant disproportionation reaction inside the refrigeration unit propagates in the grounding wire connected to the compressor housing and is consumed by the grounding resistor. Therefore, the refrigerant disproportionation reaction is suppressed.

[0010] The third-view refrigeration device, in addition to the first or second-view refrigeration device, also includes a heat exchanger. The grounding wire is connected to the heat exchanger.

[0011] According to this structure, the discharge energy that could induce a refrigerant disproportionation reaction inside the refrigeration unit propagates in the grounding wire connected by the heat exchanger and is consumed by the grounding resistor. Therefore, the refrigerant disproportionation reaction is suppressed.

[0012] The fourth viewpoint's refrigeration device, in addition to the first viewpoint's refrigeration device, also includes a compressor and a heat exchanger. The compressor has a compressor housing. The grounding resistor has a first grounding resistor and a second grounding resistor. The grounding wire has a first grounding wire and a second grounding wire. The first grounding wire is connected to the first grounding resistor and the compressor housing. The second grounding wire is connected to the second grounding resistor and the heat exchanger.

[0013] According to this structure, if one of the first and second grounding wires breaks, the discharge energy propagates to the other and is consumed by the grounding resistor. Therefore, the disproportionation reaction of the refrigerant can be suppressed more reliably.

[0014] The refrigeration apparatus of the fifth viewpoint, in any of the refrigeration apparatuses of the first to fourth viewpoints, contains 1,2-difluoroethylene (HFO-1132) as the refrigerant.

[0015] Based on this structure, the refrigerant contains HFO-1132. Therefore, the disproportionation reaction of HFO-1132, which is prone to disproportionation, can be suppressed.

[0016] The refrigeration device of the sixth viewpoint, in the refrigeration device of the fifth viewpoint, also contains 2,3,3,3-tetrafluoropropylene (HFO-1234yf) as the refrigerant.

[0017] According to this structure, since the refrigerant contains HFO-1134yf, the flammability of the refrigerant can be reduced.

[0018] The refrigeration device of the seventh viewpoint is based on the refrigeration device of the sixth viewpoint. The resistance value of the grounding 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 using the refrigerant is P (MPa). It satisfies any one of the first, second, and third conditions. 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).

[0019] According to this structure, the grounding resistor can effectively dissipate the discharge energy generated inside the refrigeration device. Therefore, it is possible to suppress the disproportionation reaction in the refrigerant composition specified in "A" of the first to third conditions.

[0020] In the cooling device of the eighth viewpoint, the grounding resistor is physically connected to the grounding wire in any of the cooling devices of the first to seventh viewpoints.

[0021] According to this structure, the grounding resistor is physically connected to the grounding wire, which does not require internal modifications to the unit and therefore does not compress the space inside the housing. Attached Figure Description

[0022] Figure 1 This is a schematic diagram showing the refrigerant circuit 60 and electrical system 40 of the refrigeration device 90.

[0023] Figure 2 This is a schematic diagram representing electrical system 40.

[0024] Figure 3 This is a cross-sectional view of compressor 11.

[0025] Figure 4 This is a schematic diagram of the structure of heat source unit 10.

[0026] Figure 5 This is a diagram showing the discharge section of compressor 11.

[0027] Figure 6 It is a model representing the discharge inside the compressor.

[0028] Figure 7 It is a graph showing the relationship between discharge time, discharge energy, and resistance value.

[0029] Figure 8 It is a graph showing the relationship between refrigerant composition, refrigerant pressure, and discharge energy.

[0030] Figure 9 It is a chart that uses points to represent the first condition.

[0031] Figure 10 It is a chart that uses points to represent the first condition.

[0032] Figure 11 It is a chart that uses points to represent the second condition.

[0033] Figure 12 It is a chart that uses points to represent the second condition.

[0034] Figure 13 It is a chart that uses points to represent the third condition.

[0035] Figure 14 It is a chart that uses points to represent the third condition. Detailed Implementation

[0036] <Implementation Method>

[0037] (1) Overall structure

[0038] Figure 1This is a schematic diagram showing the refrigerant circuit 60 and electrical system 40 of the refrigeration device 90 disclosed herein. The refrigeration device 90 can be configured as, for example, an air conditioner, a cold storage unit, a hot water supply unit, a floor heating system, etc. The refrigeration device 90 includes a heat source unit 10, a utilization unit 20, a connecting piping assembly 30, and cables 43. The refrigeration device 90 is installed within the site (IP). A commercial power supply 47 supplies power to the refrigeration device 90. The output of the commercial power supply 47 transmits power from a commercial power transformer X located outside the site (OP) to the refrigeration device 90.

[0039] (2) Detailed structure

[0040] (2-1) Heat source unit 10

[0041] The heat source unit 10 is used to generate cold or heat energy from a heat source such as external 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, a liquid receiver 16, a liquid shut-off valve 17, a gas shut-off valve 18, and internal piping T1 to T7. The heat source unit 10 also includes a heat source control unit 19 constituting the electrical system 40 and a heat source power supply unit 45.

[0042] (2-1-1) Compressor 11

[0043] The compressor 11 is a device that compresses refrigerant 65 from a low-pressure gaseous state to a high-pressure gaseous state. The compressor 11 is disposed inside the heat source housing 105. The compressor 11 is provided with a suction pipe 112 for drawing in refrigerant 65 and a discharge pipe 111 for discharging refrigerant 65. The construction of the compressor 11 will be described later.

[0044] (2-1-2) Four-way switching valve 12

[0045] The four-way switching valve 12 is a device that switches between cold energy utilization operation (providing cooling energy to the user) and heat energy utilization operation (providing heating energy to the user) by switching the path of refrigerant 65. Details are described later in the section explaining the refrigerant circuit 60.

[0046] (2-1-3) Heat source heat exchanger 13

[0047] The heat source heat exchanger 13 is a device that facilitates heat exchange between the refrigerant 65 and the air. The heat source heat exchanger 13 functions as a condenser during cold energy utilization operation and as an evaporator during heat energy utilization operation. The heat source heat exchanger 13 can also be a device that facilitates heat exchange between a medium such as water and the refrigerant.

[0048] (2-1-4) Heat source fan 14

[0049] The heat source fan 14 promotes heat exchange in the heat source heat exchanger 13 by generating an airflow. The airflow generated by the heat source fan 14 moves air outside the heat source housing 105, which functions as a heat source, into the interior of the heat source housing 105, and moves air that has completed heat exchange with the refrigerant 65 in the heat source heat exchanger 13 back to the exterior of the heat source housing 105. The heat source fan 14 is driven by a heat source fan motor.

[0050] (2-1-5) Heat source expansion valve 15

[0051] The heat source expansion valve 15 is a mechanism that reduces the pressure of the refrigerant 65 in a high-pressure liquid state, transforming it into a low-pressure gas-liquid two-phase state. Furthermore, the heat source expansion valve 15 can regulate the circulation rate of the refrigerant 65.

[0052] (2-1-6) Liquid reservoir 16

[0053] The receiver 16 is a container for removing and storing components of the liquid refrigerant 65 that are mixed in with the gaseous refrigerant 65.

[0054] (2-1-7) Liquid shut-off valve 17 and gas shut-off valve 18

[0055] Liquid shut-off valve 17 and gas shut-off valve 18 are valves that are manually opened and closed by the installer of the refrigeration unit 90 to cut off the refrigerant path.

[0056] (2-1-8) Internal piping T1~T7

[0057] Internal piping T1 to T7 connects the components housed inside the heat source housing 105. Specifically, internal piping T1 connects the discharge pipe 111 to the four-way switching valve 12. Internal piping T2 connects the four-way switching valve 12 to the heat source heat exchanger 13. Internal piping T3 connects the heat source heat exchanger 13 to the heat source expansion valve 15. Internal piping T4 connects the heat source expansion valve 15 to the liquid shut-off valve 17. Internal piping T5 connects the gas shut-off valve 18 to the four-way switching valve 12. Internal piping T6 connects the four-way switching valve 12 to the liquid reservoir 16. Internal piping T7 connects the liquid reservoir 16 to the suction pipe 112.

[0058] (2-1-9) Heat source control unit 19 and heat source power supply unit 45

[0059] The heat source control unit 19 reads the outputs of various sensors stored in the heat source unit 10 and controls various actuators. The heat source power supply unit 45 adjusts the various power supply voltages required by the heat source unit 10. These units are further explained in the description section of the electrical system 40.

[0060] (2-2) Using Unit 20

[0061] The utilization unit 20 is used to provide cold or hot energy to the user. The utilization unit 20 includes a housing 205, a heat exchanger 23, and a fan 24. The utilization unit 20 also includes a control unit 29 constituting the electrical system 40 and a power supply unit 46.

[0062] (2-2-1) Utilizing heat exchanger 23

[0063] The heat exchanger 23 is a device for heat exchange between the refrigerant 65 and air. The heat exchanger 23 functions as an evaporator during cold energy utilization operation and as a condenser during heat energy utilization operation. The heat exchanger 23 can also be a device for heat exchange between a medium such as water and the refrigerant. The heat exchanger 23 is disposed inside the housing 205.

[0064] (2-2-2) Using fan 24

[0065] The fan 24 promotes heat exchange using the heat exchanger 23 by generating airflow. Furthermore, if the refrigeration unit 90 is an air conditioner, the fan 24 delivers conditioned air to the user's location. If the refrigeration unit 90 is a hot water supply unit, the fan 24 can also function as a pump to deliver hot water to the user's location. The fan 24 is driven by a fan motor.

[0066] (2-2-3) Using control unit 29 and power supply unit 46

[0067] The control unit 29 reads the outputs of various sensors stored in the utilization unit 20 and controls various actuators. The power supply unit 46 adjusts the various power supply voltages required by the utilization unit 20. These units are further explained in the description section of the electrical system 40.

[0068] (2-3) Connecting Piping Group 30

[0069] The connecting piping assembly 30 is the piping that connects the heat source unit 10 to the utilization unit 20. The connecting piping assembly 30 has a liquid connecting piping 31 and a gas connecting piping 32. The liquid connecting piping 31 connects the liquid shut-off valve 17 to the utilization heat exchanger 23. The gas connecting piping 32 connects the gas shut-off valve 18 to the utilization heat exchanger 23.

[0070] (2-4) Cable 43

[0071] Cable 43 forms part of electrical system 40. Further details about cable 43 are provided in the description section of electrical system 40.

[0072] (3) Refrigerant circuit 60

[0073] (3-1) Refrigerant 65

[0074] Refrigerant circuit 60 circulates refrigerant 65.

[0075] In refrigerant circuit 60, refrigerant 65 is compressed, releases heat or condenses, depressurizes, absorbs heat or evaporates, and then compressed again. Refrigerant circuit 60 consists of a heat source refrigerant circuit 61, a refrigerant utilization circuit 62, and connecting piping assembly 30. Heat source refrigerant circuit 61 is part of heat source unit 10. Heat source refrigerant circuit 61 includes compressor 11, four-way switching valve 12, heat source heat exchanger 13, heat source expansion valve 15, and internal piping T1~T7 as its main components. Refrigerant utilization circuit 62 is part of utilization unit 20. Utilization refrigerant circuit 62 includes utilization heat exchanger 23.

[0076] Refrigerant 65 is a type of refrigerant that may undergo disproportionation reactions.

[0077] Refrigerant 65 is a mixed refrigerant containing the following components 1 to 2.

[0078] Component 1: 1,2-Difluoroethylene (HFO-1132)

[0079] Ingredient 2: 2,3,3,3-Tetrafluoropropylene (HFO-1234yf)

[0080] Of the two, component 1 participates more strongly in the disproportionation reaction. The molecular formula of component 1 is shown in the following chemical formula.

[0081] [Chemical Formula 1]

[0082] Component 1 can be, for example, cis-1,2-difluoroethylene (HFO-1132(Z)). Alternatively, component 1 can also be trans-1,2-difluoroethylene (HFO-1132(E)). Furthermore, component 1 can also be trifluoroethylene (HFO-1123).

[0083] (3-2) Operation of cold energy utilization

[0084] Reference Figure 1This describes the operation when the user utilizes cooling energy. In this case, the four-way switching valve 12 achieves the connection shown by the solid line. The refrigerant 65 in a low-pressure gaseous state is compressed by the compressor 11. The refrigerant 65 in a high-pressure gaseous state is discharged from the discharge pipe 111. The high-pressure gaseous refrigerant 65 condenses in the heat source heat exchanger 13, releasing heat to the air in the process of becoming a high-pressure liquid state. Then, the high-pressure liquid refrigerant 65 is depressurized by the heat source expansion valve 15, becoming a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant 65 evaporates in the heat exchanger 23, taking heat from the air in the process of becoming a low-pressure gaseous state. This means that the refrigerant 65 provides cooling energy to the user's environment. When the low-pressure gaseous refrigerant 65 passes through the receiver 16, the trace amounts of liquid refrigerant mixed in with the low-pressure gaseous refrigerant 65 are separated. Then, the low-pressure gaseous refrigerant 65 is drawn in from the suction pipe 112 of the compressor 11.

[0085] (3-3) Operation of thermal energy utilization

[0086] Reference Figure 1 This describes the operation when the user utilizes thermal energy. In this case, the four-way switching valve 12 achieves the connection shown by the dashed line. The refrigerant 65 in a low-pressure gaseous state is compressed by the compressor 11. The refrigerant 65 in a high-pressure gaseous state is discharged from the discharge pipe 111. The high-pressure gaseous refrigerant 65 condenses in the heat exchanger 23, releasing heat into the air in the process of becoming a high-pressure liquid state. This means that the refrigerant 65 provides thermal energy to the user's environment. Next, the high-pressure liquid refrigerant 65 is depressurized by the heat source expansion valve 15, becoming a low-pressure gas-liquid two-phase state. The low-pressure gas-liquid two-phase refrigerant 65 evaporates in the heat source heat exchanger 13, taking heat from the air in the process of becoming a low-pressure gaseous state. When the low-pressure gaseous refrigerant 65 passes through the receiver 16, the trace amounts of liquid refrigerant mixed in with the low-pressure gaseous refrigerant 65 are separated. Then, the low-pressure gaseous refrigerant 65 is drawn in from the suction pipe 112 of the compressor 11.

[0087] (4) Electrical system 40

[0088] Figure 2 This is a schematic diagram of the electrical system 40 of the refrigeration device 90. The electrical system 40 includes a power supply unit 46, a control unit 29, a heat source power supply unit 45, and a heat source control unit 19.

[0089] (4-1) Utilizing power supply unit 46

[0090] The power supply unit 46 includes 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 relative to the ground potential GND. The power supply voltage V1 is large enough to drive various actuators, including motors. The regulator 462 generates a power supply voltage V2 that is smaller than V1. The power supply voltage V2 is used to drive signal processing circuitry, including a processor.

[0091] (4-2) Using control unit 29

[0092] The control unit 29 receives power supply voltage V1, power supply voltage V2 and ground potential GND from the power supply unit 46 and generates control signals to drive various actuators, including the fan 24.

[0093] (4-3) Cable 43

[0094] Cable 43 connects utilization unit 20 and heat source unit 10, forming part of electrical system 40. Cable 43 houses power line 41, grounding wire 42, and communication line 49. Power line 41 transmits power voltage. Power line 41 includes a first power line 41a and a second power line 41b. First power line 41a transmits power voltage V1. Second power line 41b transmits power voltage V2. Grounding wire 42 transmits a ground potential GND, which serves as a reference potential relative to the power voltage. Communication line 49 transmits communication signals between heat source control unit 19 and utilization control unit 29.

[0095] (4-4) Heat source power supply unit 45

[0096] The heat source power supply unit 45 has capacitors 451 and 452 that respectively smooth the power supply voltages V1 and V2 transmitted via cable 43.

[0097] (4-5) Heat source control unit 19

[0098] The heat source control unit 19 receives power supply voltages V1 and V2, as well as ground potential GND, from the heat source power supply unit 45, and generates control signals to drive 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 via a communication line 49. The communication line 49 is used for communication of various information such as commands, status, and data.

[0099] (5) Structure of compressor 11

[0100] Figure 3 A cross-section of the compressor 11 is shown. The compressor 11 has a compressor housing 71, a motor 72, a crankshaft 73, a compression mechanism 74, and a terminal portion 75.

[0101] (5-1) Compressor housing 71

[0102] The compressor housing 71 is a container that houses the components of the compressor 11. Additionally, the compressor housing 71 houses the refrigerant 65 and refrigeration oil. The compressor housing 71 has an upper part 711, a cylindrical part 712, and a lower part 713 that are hermetically welded together, and has a structure capable of withstanding the high pressure of the refrigerant 65.

[0103] The compressor housing 71 is provided with the aforementioned suction pipe 112 and discharge pipe 111. The suction pipe 112 is located below the cylindrical portion 712. The discharge pipe 111 is located above the upper portion 711.

[0104] (5-2) Motor 72

[0105] The motor 72 is a device that receives an electrical supply to generate power for driving the compression mechanism 74. The motor 72 is disposed above the cylindrical portion 712. The motor 72 has a stator 721 fixed to the compressor housing 71 and a rotor 725 disposed in a rotatable manner.

[0106] The stator 721 has a stator core 722 made of laminated steel plates, a resin insulator 723, and a coil 724. The coil 724 is a winding wound around the stator core 722 and the insulator 723. The coil 724 generates an alternating magnetic field.

[0107] The rotor 725 has a rotor core 726 made of laminated steel plates, as well as permanent magnets and end plates (not shown). The permanent magnets interact with the alternating magnetic field generated by the coils 724, causing the rotor 725 to rotate as a whole. The end plates prevent the permanent magnets, which are disposed in cavities provided in the rotor core 726, from detaching.

[0108] (5-3) Crankshaft 73

[0109] The crankshaft 73 transmits the rotational force generated by the motor 72 to the compression mechanism 74.

[0110] (5-4) Compression mechanism 74

[0111] A compression mechanism 74 is located below the cylindrical portion 712 and connected to the suction pipe 112. The compression mechanism 74 includes a cylinder 741, a piston 742, and a muffler 744. The cylinder and piston 742 define a compression chamber 743. The piston 742 revolves due to the rotation of the crankshaft 73, thereby changing the volume of the compression chamber 743. As a result, the refrigerant 65 in a low-pressure gaseous state drawn in from the suction pipe 112 is compressed into a high-pressure gaseous state. The high-pressure gaseous refrigerant 65 reduces pressure pulsation in the muffler 744, thereby reducing noise. The refrigerant 65 exiting the muffler passes upward through gaps in the motor 72 (e.g., the gap between the stator 721 and the rotor 725, the core cut portion provided between the stator 721 and the cylindrical portion 712, and the gaps between adjacent coils 724 in the stator 721, etc.) and is discharged from the discharge pipe 111 to the outside of the compressor 11.

[0112] (5-5) Terminal section 75

[0113] Terminal section 75 introduces externally supplied power into the compressor 11. Terminal section 75 includes terminal pins 751, terminal base 752, leads 753, and terminal protectors 754. Terminal pins 751 are terminals for connecting external wires. Terminal base 752 is a component for erecting terminal pins 751 on the compressor housing 71. Leads 753 connect terminal pins 751 to the coil 724 of the motor 72. Terminal protectors 754 are provided on the surface of the compressor housing 71 to protect terminal pins 751 from damage by surrounding them.

[0114] (5-6) Protection circuit

[0115] In the event of a short circuit in the compressor 11 circuit, the protection circuit interrupts the current. The protection circuit includes an inverter protection device and a non-inverter sinusoidal circuit breaker.

[0116] The inverter protection device is mounted on the heat source control unit 19. The inverter protection device includes a current detection unit such as a shunt resistor. If a current value exceeding a threshold is detected in the inverter output current, the inverter protection device stops the inverter output current.

[0117] The non-inverter sinusoidal circuit breaker is mounted on the distribution panel in the commercial power supply 47. The non-inverter sinusoidal circuit breaker includes a ZTC (zero-sequence converter), a residual current relay, and a circuit breaker. In the event of a leakage current, the non-inverter sinusoidal circuit breaker stops the power supply from the commercial power supply 47 to the refrigeration unit 90.

[0118] (6) Grounding path

[0119] (6-1) Heat source unit 10

[0120] Figure 4This is a schematic diagram of the structure of heat source unit 10.

[0121] The heat source housing 105 is connected to the liquid shut-off valve 17 and the gas shut-off valve 18. The liquid shut-off valve 17 and the gas shut-off valve 18 are connected to a part of the four-way switching valve 12, a part of the liquid reservoir 16, the compressor housing 71, a part of the heat source expansion valve 15, and the heat source heat exchanger 13 via internal piping T1~T7.

[0122] The grounding wire 51 is a conductor connecting the heat source housing 105 to the ground G, and has the function of guiding the discharge energy generated inside the heat source unit 10 to the ground G. An embedded part 53 is buried in the ground G where the heat source unit 10 is grounded. The embedded part 53 is connected to the liquid shut-off valve 17 via the grounding wire 51. The grounding wire 51 forms a grounding path connecting the heat source housing 105 to the ground G.

[0123] A grounding resistor 55 is connected midway through the grounding wire 51. The grounding resistor 55 consumes the electrical energy flowing through the grounding wire 51 and converts it into heat energy. The grounding resistor 55 can be, for example, an electronic component physically connected to the grounding wire 51, or a grounding resistor.

[0124] The heat source power supply unit 45 and the heat source control unit 19, which constitute the electrical system 40, are housed in the electrical component box 48. For example... Figure 4 As shown, by appropriately configuring the electrical component box 48, a conductive path 59 is formed between the grounding potential GND of the electrical system 40 and the heat source housing 105. Due to the existence of the conductive path 59, the grounding potential GND of the electrical system 40 is also connected to the grounding wire 51 and the ground G.

[0125] (6-2) Using Unit 20

[0126] like Figure 1 As shown, the heat exchanger 23 is connected to a grounding wire 95 extending to the outside of the housing 205. The grounding wire 95 is connected in series with a grounding resistor 94. The grounding resistor 94 can be, for example, an electronic component physically connected to the grounding wire 95, or a grounding resistor.

[0127] The output terminal of the commercial power supply 47 has a first power terminal 91, a second power terminal 92, and a grounding terminal 93. The grounding terminal 93 is electrically connected to the buried part 96 in the ground. The grounding wire 95 of the utilization unit 20 is connected to the grounding terminal 93. The grounding terminal 93 is connected to the utilization heat exchanger 23 via a grounding resistor 94.

[0128] (7) Mechanism of disproportionation reaction

[0129] The applicants discovered that a disproportionation reaction is induced when refrigerant 65 is given discharge energy. The disproportionation reaction is represented by the following chemical formula.

[0130] [Chemical Formula 2]

[0131] As understood from the chemical formula, in the disproportionation reaction, the aforementioned component 1 (1,2-difluoroethylene, HFO-1132) in refrigerant 65 is decomposed and generates heat. This heat further induces the decomposition of unreacted refrigerant, causing a chain reaction of decomposition. If this occurs within the casing of the refrigeration unit 90, it may result in a rapid pressure increase within a short period of time.

[0132] (8) Discharge in compressor 11

[0133] Figure 5 These represent discharge points S1, S2, and S3 that are prone to discharge within the compressor 11. Discharge point S1 is located between terminal pin 751 and the compressor housing 71. The compressor housing 71 includes the terminal base 752 that is conductive to the compressor housing 71 and the terminal protection member 754. Discharge point S2 is located between lead 753 and the compressor housing 71. Discharge point S3 is located between coil 724 and stator core 722. Stator core 722 is conductive to the compressor housing 71. Discharges that are more likely to occur in discharge points S1 to S3 may induce a disproportionation reaction.

[0134] The discharge energy inside the compressor can be distributed according to... Figure 6 The calculation is performed using model 80. Model 80 is a closed-loop circuit consisting of a DC power supply 81, a resistor 82, and a movable contact 83 connected in series. The potential difference at 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 model 80 is used to simulate the grounding resistor 55 or grounding resistor 94 in the refrigeration device 90. The movable contact 83 can be used to set the discharge duration T (s) by changing the distance between the contacts. The magnitude of the current flowing in the movable contact 83 is the short-circuit current I (A). With the discharge duration set to T (s), the discharge energy Dis.E (J) generated in the movable contact 83 can be calculated using the following mathematical formula.

[0135] [Mathematical Expression 1]

[0136] Here, the variables and constants are as follows.

[0137] Dis.E (J): Discharge Energy

[0138] E (V): The power supply voltage of the circuit

[0139] I(A): Short-circuit current

[0140] R (Ω): Resistance value

[0141] T(s): Discharge duration

[0142] Varc (V): Voltage between contacts at the point where the electric arc is generated.

[0143] Iarc(A): Short-circuit current during arc generation

[0144] Em: A parameter determined by the contact material.

[0145] Im: A parameter determined by the contact material.

[0146] Figure 7 This graph is obtained by calculating the discharge energy Dis.E (J) as the discharge duration T (s) and resistance value R (Ω) change using the above mathematical formula and plotting it on a logarithmic scale. Reference periods P1 to P3 are marked on the horizontal axis representing the discharge duration T (s). Period P1 is the time interval from the start of discharge to the start of the inverter protection device's operation. During period P1, the inverter protection device operates. As a result, compressor 11 stops. During period P2, the voltage supplied to motor 72 becomes a rectangular wave. Period P3 is the operating period of the non-inverter sinusoidal residual current circuit breaker. When period P3 has elapsed, the power supply to the refrigeration unit 90 stops. The latest period P3 from the start of discharge provides the maximum discharge duration T (s). The end of period P3, i.e., 10 (ms) after the start of discharge, is considered the maximum discharge duration T (s).

[0147] (9) Presence or absence of disproportionation reaction

[0148] Figure 8 This is a graph showing the disproportionation boundary lines at various discharge energies (Dis.E) (J) as the content (mass%) of HFO-1132 in refrigerant 65 and the pressure P (MPa) change. For example, when the discharge energy Dis.E (J) is 3 (J), a disproportionation reaction occurs in region A1 of the graph, while no disproportionation reaction occurs in region A2.

[0149] As examples of conditions under which a disproportionation reaction does not occur, the first to third conditions will be explained below.

[0150] (9-1) First condition

[0151] The first condition is Figure 9 and Figure 10 The shaded area shown. Here, Figure 9 and Figure 10 They are in Figure 7 and Figure 8 The image now includes additional images showing shaded areas.

[0152] The first condition is: R≥0.1(Ω),…… Figure 9 E≤1000 (J), ... Figure 9 , Figure 10 A≤32 (mass%), ... Figure 10 P≤6 (MPa), ... Figure 10 .

[0153] (9-2) Second condition

[0154] The second condition is Figure 11 and Figure 12 The shaded area shown. Here, Figure 11 and Figure 12 They are in Figure 7 and Figure 8 The image now includes additional images showing shaded areas.

[0155] The second condition is: R≥1.0 (Ω), ... Figure 11 E≤250 (J), ... Figure 11 , Figure 12 A≤45 (mass%), ... Figure 12 P≤2 (MPa), ... Figure 12 .

[0156] (9-3) Third condition

[0157] The third condition is Figure 13 and Figure 14 The shaded area shown. Here, Figure 13 and Figure 14 They are in Figure 7 and Figure 8 The image now includes additional images showing shaded areas.

[0158] The third condition is: R≥10.0 (Ω), ... Figure 13 E≤30 (J), ... Figure 13 , Figure 14 A≤55 (mass%), ... Figure 14 P≤1 (MPa), ... Figure 14 .

[0159] (10) Features

[0160] (10-1)

[0161] If a discharge energy Dis.E (J) is generated inside the refrigeration device 90 that could potentially cause a disproportionation reaction of the refrigerant 65, this discharge energy Dis.E (J) can be dissipated through the grounding resistor 55. Therefore, the disproportionation reaction of the refrigerant 65 can be suppressed in the refrigeration device 90.

[0162] (10-2)

[0163] The discharge energy that could induce a disproportionation reaction of refrigerant 65 inside the refrigeration unit 90 propagates in the grounding wire 51, which is connected to the compressor housing 71, and is consumed by the grounding resistor 55. Therefore, the disproportionation reaction of refrigerant 65 is suppressed.

[0164] (10-3)

[0165] The discharge energy that could induce a disproportionation reaction of the refrigerant 65 inside the refrigeration unit 90 propagates in the grounding wire 95 connected by the heat exchanger 23 and is consumed by the grounding resistor 94. Therefore, the disproportionation reaction of the refrigerant 65 is suppressed.

[0166] (10-4)

[0167] In the event of a break in either grounding wire 51 or grounding wire 95, the discharge energy propagates to the other grounding wire and is consumed by grounding resistor 55 or grounding resistor 94. Therefore, the disproportionation reaction of refrigerant 65 can be suppressed more reliably.

[0168] (10-5)

[0169] Refrigerant 65 contains HFO-1132. Therefore, the disproportionation reaction of HFO-1132, which is prone to disproportionation, can be suppressed. Refrigerant 65 may also contain HFO-1134yf. Since refrigerant 65 contains HFO-1134yf, the flammability of refrigerant 65 can be reduced.

[0170] (10-6)

[0171] The grounding resistors 55 and 94 can effectively dissipate the discharge energy generated inside the refrigeration unit 90. Therefore, the disproportionation reaction can be suppressed in the refrigerant composition specified in "A" of the first to third conditions.

[0172] (10-7)

[0173] The grounding resistors 55 and 94 are physically connected to the grounding wires 51 and 95, requiring no modification to the interior of the casing, thus not compressing the space inside the casing.

[0174] <Modifications of the above embodiments>

[0175] (11) Variation Example

[0176] (11-1) Variation A

[0177] In the above embodiment, a grounding resistor 55 is provided on the grounding wire 51 of the heat source unit 10, and a grounding resistor 94 is also provided on the grounding wire 95 of the utilization unit 20. Alternatively, only one of the grounding resistor 55 of the grounding wire 51 or the grounding resistor 94 of the grounding wire 95 may be provided.

[0178] (11-2) Variation B

[0179] The conductive path 59 that connects the ground potential GND of the electrical system 40 to the heat source housing 105 is not necessarily required. In other words, the ground potential GND can also be insulated from the heat source housing 105.

[0180] (11-3) Variation C

[0181] The structure of the electrical system 40 is not limited to the structure described. For example, the heat source power supply unit 45 may also generate its own power supply voltage V2 by having a regulator. Furthermore, the heat source power supply unit 45 may also receive power from the commercial power supply 47. The number of power lines 41 is not limited to the two power lines 41a and 41b, but may be one or more.

[0182] (11-4) Variation D

[0183] The grounding resistor 55 can also be disposed inside the heat source housing 105. For example, the grounding resistor 55 can also be mounted on the circuit board of the electrical component box 48.

[0184] (11-5) Variation E

[0185] The refrigeration device 90 described above has a heat source unit 10 and a utilization unit 20 that are separate from each other. Alternatively, the refrigeration device 90 may also be configured as a single unit in which the heat source unit 10 and the utilization unit 20 share the same housing.

[0186] Summary

[0187] The embodiments of this disclosure have been described above, but it should be understood that various changes in manner and details can be made without departing from the spirit and scope of this disclosure as set forth in the claims.

[0188] Label Explanation

[0189] 10: Heat source unit

[0190] 11: Compressor

[0191] 17: Liquid shut-off valve

[0192] 18: Gas shut-off valve

[0193] 19: Heat source control unit

[0194] 20: Utilizing Units

[0195] 23: Utilizing a heat exchanger

[0196] 29: Using the control unit

[0197] 30: Liaison Piping Team

[0198] 40: Electrical System

[0199] 41: Power cord

[0200] 41a: First power line

[0201] 41b: Second power supply line

[0202] 42: Grounding wire

[0203] 43: Cable

[0204] 45: Heat source power supply unit (power supply unit)

[0205] 46: Utilizing power supply units

[0206] 47: Commercial Power Supply

[0207] 48: Electrical Parts Box

[0208] 49: Communication line

[0209] 51: Grounding wire (first grounding wire)

[0210] 53: Installation Department

[0211] 55: Grounding resistor (first grounding resistor)

[0212] 59: Conduction Path

[0213] 60: Refrigerant circuit

[0214] 61: Heat source and refrigerant circuit (refrigerant circuit)

[0215] 62: Utilizing the refrigerant circuit (refrigerant circuit)

[0216] 65: Refrigerant

[0217] 71: Compressor housing

[0218] 72: Motor

[0219] 73: Crankshaft

[0220] 74: Compression mechanism

[0221] 75: Terminal section

[0222] 90: Refrigeration equipment

[0223] 94: Grounding resistor (second grounding resistor)

[0224] 95: Grounding wire (second grounding wire)

[0225] 105: Heat source casing (casing)

[0226] 111: Discharge pipe

[0227] 112: Inhalation tube

[0228] 205: Utilizing the casing (shell)

[0229] 711: Upper part

[0230] 712: Cylindrical section

[0231] 713: Lower part

[0232] 721: Stator

[0233] 22: Stator core

[0234] 723: Insulating components

[0235] 724: Coil

[0236] 725: Rotor

[0237] 726: Rotor core

[0238] 751: Terminal pin

[0239] 752: Terminal base

[0240] 753: Lead wire

[0241] 754: Terminal protection components

[0242] G: Ground

[0243] GND: Grounding potential

[0244] E: Voltage between contacts

[0245] I: Short-circuit current

[0246] T: Discharge duration

[0247] A (mass%): Refrigerant component ratio

[0248] Dis.E (J): Discharge Energy

[0249] P (MPa): Pressure

[0250] R (Ω): Resistance value

[0251] Existing technical documents

[0252] [Patent Literature]

[0253] Patent Document 1: International Publication No. WO2018 / 168776

Claims

1. A refrigeration device (90) comprising: Housing (105, 205); The refrigerant loop (60, 61, 62) circulates the refrigerant (65) that may undergo a disproportionation reaction; Power supply units (45, 46) receive power from commercial power supply (47); Grounding wires (51, 95) connect the housing to the ground (G) outside the housing; as well as A grounding resistor (55, 94) is connected to the grounding wire and has a resistance value of 0.1Ω or higher.

2. The refrigeration device according to claim 1, wherein, The refrigeration device also includes a compressor (11) having a compressor housing (71). The grounding wire (51) is connected to the compressor housing.

3. The refrigeration device according to claim 1 or 2, wherein, The refrigeration device also utilizes a heat exchanger (23). The grounding wire (95) is connected to the heat exchanger.

4. The refrigeration device according to claim 1, wherein, The refrigeration device also includes a compressor (11) and a heat exchanger (23), the compressor (11) having a compressor housing (71). The grounding resistor has a first grounding resistor (55) and a second grounding resistor (94). The grounding wire has the following characteristics: The first grounding wire (51) is connected to the first grounding resistor and the compressor housing; and The second grounding wire (95) is connected to the second grounding resistor and the heat exchanger.

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

6. The refrigeration device according to claim 5, wherein, The refrigerant (65) also contains 2,3,3,3-tetrafluoropropylene (HFO-1234yf).

7. The refrigeration apparatus according to claim 6, wherein, The resistance value of the grounding resistors (55, 94) is R (Ω). The proportion of 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 when using the refrigerant is P (MPa). If any one of the first, second, and third conditions is met, 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).

8. The refrigeration apparatus according to any one of claims 1 to 7, wherein, The grounding resistors (55, 94) are physically connected to the grounding wires (51, 95).

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