Air conditioning unit

Abstract

An air conditioning unit is provided with an electric component unit (420), a first heat exchanger (12), a second heat exchanger (23), a fan (44), a casing (41), and a partition plate (46). The first heat exchanger (12) exchanges heat between a combustible first refrigerant and air. The second heat exchanger (23) exchanges heat between a non-combustible second refrigerant and air. The fan (44) causes air to flow to the first heat exchanger (12) and the second heat exchanger (23). The partition plate (46) partitions the inside of the housing (41) into a first chamber (S1) in which the first heat exchanger (12), the second heat exchanger (23), and the fan (44) are disposed, and a second chamber (S2) in which the electric component unit (420) is disposed. A communication hole (461) for communicating the first chamber (S1) and the second chamber (S2) is provided in the partition plate (46) at a position above the uppermost first welded section (121) among the plurality of welded sections (120) of the first heat exchanger (12).

Description

Technical Field

[0001] The present disclosure relates to an air conditioning unit. Background Art

[0002] Patent Document 1 (Japanese Patent No. 5430604) discloses a binary refrigeration device including a low-stage refrigeration cycle using a carbon dioxide refrigerant and a high-stage refrigeration cycle for assisting heat dissipation of the low-stage refrigeration cycle. In the binary refrigeration device of Patent Document 1, the high-stage evaporator and the low-stage condenser perform heat exchange through a cascade condenser, and an auxiliary radiator and a high-stage condenser provided in the front stage of the low-stage refrigeration cycle of the cascade condenser are integrated to form an integrated radiator. Summary of the Invention

[0003] Problems to be Solved by the Invention

[0004] However, in the above Patent Document 1, it is disclosed that an HC-based refrigerant, an HFC refrigerant, an HFO refrigerant, etc. are used in the high-stage refrigeration cycle. If a flammable refrigerant leaks from the high-stage condenser, there is a possibility of ignition with the electrical component unit as the ignition source.

[0005] Means for Solving the Problems

[0006] The air conditioning unit according to the first aspect includes an electrical component unit, a first heat exchanger, a second heat exchanger, a fan, a housing, and a partition plate. The first heat exchanger exchanges heat between a combustible first refrigerant and air. The second heat exchanger exchanges heat between a non-combustible second refrigerant and air. The fan causes air to flow toward the first heat exchanger and the second heat exchanger. The housing houses the electrical component unit, the first heat exchanger, the second heat exchanger, and the fan. The partition plate divides the interior of the housing into a first chamber in which the first heat exchanger, the second heat exchanger, and the fan are arranged and a second chamber in which the electrical component unit is arranged. A communication hole for communicating the first chamber and the second chamber is provided at a position above the uppermost first welding portion among a plurality of welding portions of the partition plate with respect to the first heat exchanger.

[0007] In the air conditioning unit according to the first aspect, through the communication hole provided in the partition plate and the fan arranged in the first chamber, air can flow from the second chamber in which the electrical component unit is arranged to the first chamber in which the first heat exchanger through which the first refrigerant flows is arranged. Further, since the communication hole is provided at a position higher than the uppermost first welding portion of the first heat exchanger through which the combustible first refrigerant flows, even if the first refrigerant leaks in the first chamber, it is possible to suppress the first refrigerant from flowing to a position above the communication hole. Therefore, it is possible to reduce the possibility of ignition with the electrical component unit in the second chamber as the ignition source.

[0008] In the air conditioning unit of the second aspect, in the air conditioning unit of the first aspect, the communication hole is a hole for guiding the air around the electrical component unit to the fan.

[0009] In the air conditioning unit of the second aspect, since the air around the electrical component unit that would become a fire source is guided to the first chamber, even if the first refrigerant leaks, the flow of the first refrigerant around the electrical component unit can be suppressed.

[0010] The air conditioning unit of the third aspect, in the air conditioning unit of the first aspect or the second aspect, further includes a flared opening. The flared opening is disposed in the first chamber and has a cylindrical portion surrounding the fan. The lower end of the electrical component unit is located above the lower end of the cylindrical portion.

[0011] In the air conditioning unit of the third aspect, the fan is disposed inside the cylindrical portion of the flared opening. Generally, the first refrigerant is heavier than air, so even if the first refrigerant leaks, the first refrigerant will stay at a position below the lower end of the cylindrical portion. Here, since the lower end of the substrate on which the electrical component unit is mounted is located above the lower end of the cylindrical portion, the flow of the first refrigerant to the electrical component unit can be further suppressed.

[0012] The air conditioning unit of the fourth aspect, in the air conditioning unit according to any one of the first to third aspects, the lower end of the electrical component unit is located above the first welding portion.

[0013] In the air conditioning unit of the fourth aspect, even if the first refrigerant leaks, the first refrigerant stays at a position below the first welding portion. Here, since the lower end of the substrate on which the electrical component unit is mounted is located above the first welding portion, the flow of the first refrigerant to the electrical component unit can be further suppressed.

[0014] The air conditioning unit of the fifth aspect, in the air conditioning unit according to any one of the first to fourth aspects, the first heat exchanger is located below the second heat exchanger.

[0015] In the air conditioning unit of the fifth aspect, the first heat exchanger through which the combustible refrigerant flows is disposed below the second heat exchanger through which the non-combustible refrigerant flows. Therefore, even if the first refrigerant leaks, the first refrigerant is likely to stay below, so an air conditioning unit that can easily suppress the flow of the first refrigerant to the electrical component unit can be achieved.

[0016] The air conditioning unit according to the sixth aspect, among the air conditioning units according to any one of the first to fifth aspects, further includes a first compressor, a second compressor, and a bell mouth. The first compressor is disposed in the second chamber and compresses the first refrigerant. The second compressor is disposed in the second chamber and compresses the second refrigerant. The bell mouth is disposed in the first chamber and has a cylindrical portion surrounding the fan. The terminals of the first compressor and the terminals of the second compressor are located above the lower end of the cylindrical portion.

[0017] In the air conditioning unit according to the sixth aspect, even when the first refrigerant leaks, the first refrigerant stays at a position below the lower end of the cylindrical portion of the bell mouth. Here, since the terminals are located above the lower end of the cylindrical portion, the possibility of ignition with the terminals in the second chamber as the ignition source can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a binary refrigeration cycle device including an outdoor unit according to an embodiment of the present disclosure.

[0019] Figure 2A is a schematic cross-sectional view of the outdoor unit.

[0020] Figure 2B is a schematic top view of the outdoor unit.

[0021] Figure 3 is a diagram showing the operation during the refrigeration operation of the binary refrigeration cycle device.

[0022] Figure 4 is a diagram showing the operation during the heating operation of the binary refrigeration cycle device.

[0023] Figure 5 is a diagram showing a plurality of welded portions. DETAILED DESCRIPTION

[0024] (1) Structure of the binary refrigeration cycle device

[0025] As Figure 1 shown, the binary refrigeration cycle device 1 including the outdoor unit 2 according to an embodiment of the present disclosure is a device for cooling and heating the interior of a building or the like by performing a vapor compression refrigeration cycle operation.

[0026] The binary refrigeration cycle device 1 has a first cycle 10 and a second cycle 20. The binary refrigeration cycle device 1 of the present embodiment has a binary refrigerant circuit composed of a vapor compression type first cycle 10 and a vapor compression type second cycle 20, and performs a binary refrigeration cycle.

[0027] The first cycle 10 provides a cycle for a combustible first refrigerant. The first refrigerant has a critical point of 40°C or higher, for example. The first refrigerant is, for example, a hydrocarbon-based refrigerant, R1234yf, R1234ze, R32, etc., and is R290 in the present embodiment. The specific gravity of the first refrigerant is greater than the specific gravity of air.

[0028] The second cycle 20 provides a cycle for a non-combustible second refrigerant. The second refrigerant has a critical point of less than 40°C, for example. The second refrigerant contains carbon dioxide, for example, and is a single refrigerant of carbon dioxide in the present embodiment.

[0029] The first cycle 10 and the second cycle 20 are thermally connected via a cascade heat exchanger 30.

[0030] The binary refrigeration cycle device 1 includes an outdoor unit 2 and an indoor unit 3. The binary refrigeration cycle device 1 is configured such that the outdoor unit 2 and the indoor unit 3 are connected to each other via connection pipes 4 and 5.

[0031] (1-1) First cycle

[0032] The first cycle 10 constitutes a subcooling circuit during refrigeration operation. The first cycle 10 includes a first compressor 11, a first heat exchanger 12, a first expansion mechanism 13, and a cascade heat exchanger 30.

[0033] The first compressor 11 is a device for compressing the first refrigerant and is constituted by, for example, a positive displacement compressor such as a scroll type that can change the operating capacity by performing variable frequency control of a compressor motor.

[0034] As shown in Figure 2, the first compressor 11 has a first terminal 111. A wiring for power supply is connected to the first terminal 111. Here, the first terminal 111 is a wiring harness connection part.

[0035] The first heat exchanger 12 is a device for performing heat exchange between the first refrigerant and outdoor air. In the first heat exchanger 12, the first refrigerant obtains cold energy or heat energy from the outdoor air. The first heat exchanger 12 is constituted by, for example, a finned tube type heat exchanger including a plurality of heat transfer tubes and fins.

[0036] The first expansion mechanism 13 is a device for decompressing the first refrigerant and is, for example, an electric expansion valve.

[0037] The cascade heat exchanger 30 is a device for performing heat exchange between the first refrigerant and the second refrigerant without mutual mixing. The cascade heat exchanger 30 is constituted by, for example, a plate type heat exchanger. The cascade heat exchanger 30 has a first flow path 31 belonging to the first cycle 10 and a second flow path 32 belonging to the second cycle 20. The gas side of the first flow path 31 is connected to the first compressor 11, and the liquid side of the first flow path 31 is connected to the first expansion mechanism 13.

[0038] When the first heat exchanger 12 is used as a condenser and the second heat exchanger 23 of the second cycle 20 described later is used as a radiator, the cascade heat exchanger 30 serves an auxiliary role for the second cycle 20 for the purpose of subcooling the second refrigerant cooled by the second heat exchanger 23.

[0039] (1-2) Second cycle

[0040] The second cycle 20 includes a second compressor 21, a switching mechanism 22, a second heat exchanger 23, a cascade heat exchanger 30, a second expansion mechanism 24, and a third heat exchanger 25.

[0041] The second compressor 21 is a device for compressing the second refrigerant, and is composed of, for example, a positive displacement compressor such as a scroll type that can change the operating capacity by variable frequency control of the compressor motor.

[0042] As shown in FIG. 2, the second compressor 21 has a second terminal 211. A wiring for power supply is connected to the second terminal 211. Here, the second terminal 211 is a harness connection portion.

[0043] The switching mechanism 22 is for the first state in which the second heat exchanger 23 functions as a radiator for the second refrigerant and the third heat exchanger 25 functions as an evaporator for the second refrigerant (refer to the solid line of the switching mechanism 22 in Figure 1 ), and the second state in which the second heat exchanger 23 functions as an evaporator for the second refrigerant and the third heat exchanger 25 functions as a radiator for the second refrigerant (refer to the dashed line of the switching mechanism 22 in Figure 1 ). The switching mechanism 22 is, for example, a four-way switching valve. Further, the switching mechanism 22 connects the discharge side of the second compressor 21 to the gas side of the second heat exchanger 23 and connects the suction side of the second compressor 21 to the gas side of the third heat exchanger 25 in the first state. And, the switching mechanism 22 connects the discharge side of the second compressor 21 to the gas side of the third heat exchanger 25 and connects the suction side of the second compressor 21 to the gas side of the second heat exchanger 23 in the second state.

[0044] The second heat exchanger 23 is a device for performing heat exchange between the second refrigerant and outdoor air. In the second heat exchanger 23, the second refrigerant obtains cold energy or heat energy from the outdoor air. The second heat exchanger 23 is composed of, for example, a finned tube type heat exchanger formed by a plurality of heat transfer tubes and fins.

[0045] The second cycle 20 has a second flow path 32 of the cascade heat exchanger 30. In the second state, the gas side of the second flow path 32 is connected to the second heat exchanger 23, and the liquid side thereof is connected to the third heat exchanger 25.

[0046] The second expansion mechanism 24 is a device for decompressing the second refrigerant, for example, an electric expansion valve.

[0047] The third heat exchanger 25 is a device for performing heat exchange between the second refrigerant and indoor air, and is constituted by, for example, a finned tube heat exchanger including a plurality of heat transfer tubes and fins.

[0048] (1-3) Outdoor unit

[0049] In the following description, expressions indicating directions such as "up", "down", "front", etc. are appropriately used, but they indicate the respective directions in the state where the outdoor unit 2 is installed outdoors and is normally used. In the present embodiment, the vertical direction is the up-down direction.

[0050] The outdoor unit 2 is disposed in a space different from the space in which the indoor unit 3 is disposed. Here, the outdoor unit 2 is installed outdoors (near the roof of a building, the outer wall surface of a building, etc.).

[0051] The outdoor unit 2 includes a part of the above-described first cycle 10 and second cycle 20, a housing 41, an electric component unit 420 including electric components 42 and a substrate 43, a fan 44, a flare 45, a partition plate 46, and a refrigerant leakage sensor 47. Specifically, the outdoor unit 2 includes Figure 1 the first compressor 11, the first heat exchanger 12, the first expansion mechanism 13, the second compressor 21, the switching mechanism 22, the second heat exchanger 23, the second expansion mechanism 24, the cascade heat exchanger 30, the housing 41 shown in FIG. 2, the electric components 42, the substrate 43, the fan 44, the flare 45, the partition plate 46, and the refrigerant leakage sensor 47.

[0052] The housing 41 houses the first compressor 11, the first heat exchanger 12, the first expansion mechanism 13, the second compressor 21, the switching mechanism 22, the second heat exchanger 23, the second expansion mechanism 24, the cascade heat exchanger 30, the electric components 42, the substrate 43, the fan 44, the flare 45, the partition plate 46, and the refrigerant leakage sensor 47.

[0053] The housing 41 shown in FIG. 2 has a substantially rectangular parallelepiped shape. Specifically, the housing 41 includes a front plate 411, a top plate 412, a bottom plate 413, and side plates 414.

[0054] The front plate 411 is a plate-like member constituting the front side surface of the housing 41. An air outlet is formed in the front plate 411. The air outlet is an opening for blowing the outdoor air taken into the interior from the outside of the housing 41 to the outside of the housing 41.

[0055] The top plate 412 is a plate-like member that forms the upper side surface of the housing 41. The bottom plate 413 is a plate-like member that forms the lower side surface of the housing 41. The top plate 412 and the bottom plate 413 face each other.

[0056] The side plate 414 is a plate-like member that forms the side surface of the housing 41. The lower part of the side plate 414 is fixed to the bottom plate 413.

[0057] An opening 415 is formed in the housing 41 for allowing outdoor air to flow toward a communication hole 461 of a partition plate 46 described later. Here, the opening 415 is formed in the side plate 414 that divides a second chamber S2 described later. In addition, the opening 415 does not necessarily need to be formed in the side plate 414 and can be provided in any member that divides the second chamber S2 from the outside of the housing 41.

[0058] The electrical component unit 420 is formed by mounting electrical components 42 (electrical parts) on a substrate 43.

[0059] The electrical component 42 controls controlled objects such as a first compressor 11, a second compressor 21, a first expansion mechanism 13, a switching mechanism 22, and a second expansion mechanism 24. The electrical component 42 includes, for example, cooled components such as power elements, reactors, capacitors, and wiring connection parts.

[0060] The electrical component 42 is mounted on the substrate 43. The substrate 43 is, for example, a printed circuit board. The substrate 43 extends in the vertical direction. Here, a plurality of electrical components 42 are mounted on the substrate 43.

[0061] The fan 44 causes air to flow toward the first heat exchanger 12 and the second heat exchanger 23. In the present embodiment, the fan 44 causes outdoor air to flow toward both the first heat exchanger 12 and the second heat exchanger 23. Here, the fan 44 generates an air flow as follows: guiding outdoor air to the first heat exchanger 12 and the second heat exchanger 23, and after exchanging heat with the first refrigerant flowing in the first heat exchanger 12 and then with the second refrigerant flowing in the second heat exchanger 23, discharging it to the outside. The fan 44 is driven by a fan motor. In addition, a fan for causing air to flow toward the first heat exchanger 12 and a fan for causing air to flow toward the second heat exchanger 23 may be provided separately.

[0062] The bell mouth 45 is disposed on the blowing side of the fan 44. The bell mouth 45 has a cylindrical portion that surrounds the fan 44. The cylindrical portion forms an opening. The fan 44 is disposed inside the cylindrical portion.

[0063] In FIG. 2, when viewed from the front, the fan 44 and the bell mouth 45 overlap with the first heat exchanger 12 and the second heat exchanger 23. The bell mouth 45 faces a blowout port (not shown) formed in the front plate 411 of the housing 41.

[0064] The refrigerant leakage sensor 47 detects the leakage of the first refrigerant. The refrigerant leakage sensor 47 is disposed below inside the housing 41. Additionally, the refrigerant leakage sensor 47 may also detect the leakage of the second refrigerant.

[0065] The partition plate 46 is a plate-like member extending in the vertical direction. The lower portion of the partition plate 46 is fixed to the bottom plate 413 of the housing 41.

[0066] The partition plate 46 divides the inside of the housing 41 into a first chamber S1 and a second chamber S2. The first chamber S1 and the second chamber S2 are spaces defined by the front plate 411, the top plate 412, the bottom plate 413, and the side plates 414 of the housing 41 and the partition plate 46, respectively.

[0067] Here, the first chamber S1 is a blowing chamber, which is an air guiding path for the air inhaled from the suction port of the outdoor unit 2 to flow toward the blowout port. The second chamber S2 is a machinery chamber.

[0068] In the present embodiment, the first heat exchanger 12, the second heat exchanger 23, the fan 44, and the bellmouth 45 are disposed in the first chamber S1. The first compressor 11, the second compressor 21, the switching mechanism 22, the first expansion mechanism 13, the second expansion mechanism 24, the electric component unit 420 including the electric components 42 and the substrate 43, and the refrigerant leakage sensor 47 are disposed in the second chamber S2.

[0069] A communication hole 461 is provided in the partition plate 46. As Figure 5 shown, the communication hole 461 is provided at a position above the uppermost first welding portion 121 among the plurality of welding portions 120 of the first heat exchanger 12.

[0070] Additionally, the welding portion 120 is a portion in the first chamber S1 where there is a possibility of the first refrigerant leaking from the first heat exchanger 12. The welding portion 120 in the present embodiment is a joint portion between the heat transfer tubes constituting the first heat exchanger 12, a joint portion between the heat transfer tube and the fin, etc. The heat transfer tubes include U-shaped tubes, branch tubes, etc. Here, the plurality of welding portions 120 are joint portions between the hairpin-shaped tubes and the U-shaped tubes or branch tubes. Additionally, in the case of a heat exchanger such as a microchannel type where the heat transfer tubes and the fins are welded, the welded portion also becomes a welding portion.

[0071] In Figure 2A it, P1 represents the height position of the communication hole 461 in the vertical direction, and P2 represents the height position of the first welding portion 121 in the vertical direction. The height position P1 of the communication hole 461 in the vertical direction is the lowermost end of the communication hole 461. Therefore, the height position P1 of the lowermost end of the communication hole 461 is higher than the height position of the first welding portion 121 in the vertical direction.

[0072] The communication hole 461 is a hole for guiding the outdoor air flowing into the second chamber S2 from the opening 415 of the housing 41 to the first chamber S1. The communication hole 461 of the present embodiment is a hole for guiding the air around the electrical component unit 420 including the electrical components 42 and the substrate 43 to the fan 44. In other words, the communication hole 461 is a hole for guiding the outdoor air around the electrical component unit 420 including the electrical components 42 and the substrate 43 in the second chamber S2 to the fan 44 in the first chamber S1.

[0073] In FIG. 2, the communication hole 461 is located above the upper end of the first heat exchanger 12. And, the height position P1 of the communication hole 461 overlaps with the second heat exchanger 23.

[0074] And, the communication hole 461 is located above the lower end 451 of the cylindrical portion of the bell mouth 45. And, the communication hole 461 is located above the first terminal 111 of the first compressor 11 and the second terminal 211 of the second compressor 21.

[0075] In addition, the communication hole 461 is located above the lower end 431 of the electrical component unit 420 (here, the substrate 43). Here, the height position P1 of the lowermost end of the communication hole 461 is located above the lowermost electrical component 42 among the plurality of electrical components 42.

[0076] Here, the arrangement of various devices housed inside the housing 41 of the outdoor unit 2 will be described.

[0077] In the first chamber S1, the first heat exchanger 12 is located below the second heat exchanger 23. In other words, at least a part of the first heat exchanger 12 is located below the second heat exchanger 23. It may be that the entire first heat exchanger 12 is located below the second heat exchanger 23, or a part of the first heat exchanger 12 is located below the second heat exchanger 23.

[0078] In addition, the first heat exchanger 12 and the second heat exchanger 23 may be separate or integrated. And, the size of the first heat exchanger 12 may be of the same degree as the size of the second heat exchanger 23, or may be smaller than the size of the second heat exchanger 23 in the height direction in the vertical direction.

[0079] And, in the second chamber S2, the electrical component unit 420 including the electrical components 42 and the substrate 43 is arranged above the first compressor 11 and the second compressor 21.

[0080] Further, inside the housing 41, the lower end 431 of the electrical component unit 420 (here, the substrate 43) is located above the lower end 451 of the cylindrical portion of the bell mouth 45. In other words, the height position of the lower end 431 of the electrical component unit 420 (here, the substrate 43 with the electrical components 42) in the vertical direction is higher than the opening lower end 451 of the bell mouth 45 disposed on the blowing side of the fan 44.

[0081] Here, the lowermost electrical component 42 among the plurality of electrical components 42 is located above the lower end 451 of the cylindrical portion of the bell mouth 45.

[0082] Further, the lower end 431 of the electrical component unit 420 (here, the substrate 43) is located above the first welding portion 121. In other words, the height position of the electrical component unit 420 (here, the substrate 43 with the electrical components 42) is above the height position P1 of the first welding portion 121.

[0083] Here, the lowermost electrical component 42 among the plurality of electrical components 42 is located above the first welding portion 121.

[0084] Further, the first terminal 111 of the first compressor 11 and the second terminal 211 of the second compressor 21 are located above the lower end 451 of the cylindrical portion of the bell mouth 45. Here, the lower ends of the first terminal 111 of the first compressor 11 and the second terminal 211 of the second compressor 21 are located above the lower end 451 of the cylindrical portion of the bell mouth 45.

[0085] (1-4) Indoor unit

[0086] The indoor unit 3 is installed indoors (inside a building). As described above, the indoor unit 3 is connected to the outdoor unit 2 via the connecting pipes 4 and 5 and forms a part of the second cycle 20.

[0087] As Figure 1 shown, the indoor unit 3 has a third heat exchanger 25. Here, the indoor unit 3 is installed by being embedded or suspended from the ceiling or the like indoors in a building or the like, or is installed on the wall surface or the like indoors by being wall-mounted or the like.

[0088] (1-5) Connecting pipes

[0089] The connecting pipes 4 and 5 are refrigerant pipes that are constructed on-site when the binary refrigeration cycle device 1 is installed in a building or other installation site. One end of the liquid-side connecting pipe 4 is connected to the liquid-side end of the outdoor unit 2, and the other end of the connecting pipe 4 is connected to the liquid-side end of the third heat exchanger 25 of the indoor unit 3. One end of the gas-side connecting pipe 5 is connected to the gas-side end of the outdoor unit 2, and the other end of the connecting pipe 5 is connected to the gas-side end of the third heat exchanger 25 of the indoor unit 3.

[0090] (1-6) Control unit

[0091] The component devices of the above-mentioned outdoor unit 2 and indoor unit 3 are controlled by the control unit 6. The control unit 6 is constituted by communicatively connecting the electrical components 42, the substrate 43, etc. provided in the outdoor unit 2 and the control substrate (not shown) provided in the indoor unit 3. In addition, for convenience, the control unit 6 is illustrated at a position far from the outdoor unit 2, the indoor unit 3, etc. The control unit 6 controls the component devices of the binary refrigeration cycle device 1 (here, the outdoor unit 2 and the indoor unit 3). In other words, the control unit 6 performs the operation control of the entire binary refrigeration cycle device 1. Figure 1 In, for convenience, the control unit 6 is illustrated at a position far from the outdoor unit 2, the indoor unit 3, etc. The control unit 6 controls the component devices of the binary refrigeration cycle device 1 (here, the outdoor unit 2 and the indoor unit 3). In other words, the control unit 6 performs the operation control of the entire binary refrigeration cycle device 1.

[0092] The control unit 6 is implemented by a computer. The control unit 6 includes a control arithmetic device and a storage device. The control arithmetic device can use a processor such as a CPU or a GPU. The control arithmetic device reads the program stored in the storage device and performs prescribed image processing and arithmetic processing according to the program. In addition, the control arithmetic device can write the arithmetic result into the storage device according to the program or read the information stored in the storage device.

[0093] (2) Operation of the binary refrigeration cycle device

[0094] Use Figures 1 to 4 To explain the operation of the binary refrigeration cycle device 1. The binary refrigeration cycle device 1 can perform a refrigeration operation for cooling indoor air and a heating operation for heating indoor air for indoor air conditioning. In the refrigeration operation and the heating operation, the operation of the binary refrigeration cycle device 1 is controlled by the control unit 6.

[0095] (2-1) Refrigeration operation

[0096] As Figure 3 shown, during the refrigeration operation, the switching mechanism 22 is switched to the first state (the state where the switching mechanism 22 is a solid line), so that the second heat exchanger 23 functions as a radiator for the second refrigerant, and the third heat exchanger 25 functions as an evaporator for the second refrigerant.

[0097] In the second cycle 20, the second refrigerant discharged from the second compressor 21 is conveyed to the second heat exchanger 23 through the switching mechanism 22. The second refrigerant conveyed to the second heat exchanger 23 exchanges heat with the outdoor air supplied by the fan 44 and is cooled, thereby dissipating heat. The second refrigerant that has dissipated heat in the second heat exchanger 23 is conveyed to the second flow path 32 of the cascade heat exchanger 30. The second refrigerant conveyed to the second flow path 32 exchanges heat with the first refrigerant flowing in the first flow path 31 in the cascade heat exchanger 30 and is further cooled. The second refrigerant that has been further cooled in the cascade heat exchanger 30 is decompressed by the second expansion mechanism 24 and then flows out of the outdoor unit 2.

[0098] The second refrigerant flowing out of the outdoor unit 2 flows into the indoor unit 3 via the liquid-side connection pipe 4. In the indoor unit 3, the second refrigerant is conveyed to the third heat exchanger 25. The second refrigerant conveyed to the third heat exchanger 25 exchanges heat with the indoor air and is heated, thereby evaporating. The second refrigerant that has evaporated in the third heat exchanger 25 flows out of the indoor unit 3.

[0099] The second refrigerant flowing out of the indoor unit 3 flows into the outdoor unit 2 via the gas-side connection pipe 5. In the outdoor unit 2, the second refrigerant is sucked into the second compressor 21 again through the switching mechanism 22.

[0100] In the first cycle 10, the first refrigerant discharged from the first compressor 11 is conveyed to the first heat exchanger 12. The first refrigerant conveyed to the first heat exchanger 12 exchanges heat with the outdoor air supplied by the fan 44 and is cooled, thereby condensing. The first refrigerant that has condensed in the first heat exchanger 12 is decompressed by the first expansion mechanism 13 and then conveyed to the first flow path 31 of the cascade heat exchanger 30. The first refrigerant conveyed to the first flow path 31 exchanges heat with the second refrigerant flowing in the second flow path 32 in the cascade heat exchanger 30 and is heated, thereby evaporating. The first refrigerant that has evaporated in the cascade heat exchanger 30 is sucked into the first compressor 11 again.

[0101] (2-2) Heating operation

[0102] As Figure 4 shown, during the heating operation, the switching mechanism 22 is switched to the second state (the state where the switching mechanism 22 is shown as a dashed line), such that the second heat exchanger 23 functions as an evaporator for the second refrigerant and the third heat exchanger 25 functions as a radiator for the second refrigerant. Also, during the heating operation, the first compressor 11 is not started and the first refrigerant in the first cycle 10 does not circulate.

[0103] In the second cycle 20, the second refrigerant discharged from the second compressor 21 flows out of the outdoor unit 2 through the switching mechanism 22.

[0104] The refrigerant flowing out of the outdoor unit 2 flows into the indoor unit 3 via the connection pipe 5 on the gas side. In the indoor unit 3, the second refrigerant is delivered to the third heat exchanger 25. The second refrigerant delivered to the third heat exchanger 25 is cooled by heat exchange with indoor air, thereby dissipating heat. The second refrigerant after dissipating heat in the third heat exchanger 25 flows out of the indoor unit 3.

[0105] The second refrigerant flowing out of the indoor unit 3 flows into the outdoor unit 2 via the connection pipe 4 on the liquid side. In the outdoor unit 2, the second refrigerant is delivered to the second heat exchanger 23 through the second expansion mechanism 24 and the second flow path 32 of the cascade heat exchanger 30. The second refrigerant delivered to the second heat exchanger 23 is heated by heat exchange with the outdoor air supplied by the fan 44, thereby evaporating. The second refrigerant after evaporation in the second heat exchanger 23 is sucked into the second compressor 21 again through the switching mechanism 22.

[0106] (3) Flow of the first refrigerant when the refrigerant leaks

[0107] As Figure 2A shown by the arrow A, in the outdoor unit 2, outdoor air flows from the opening 415 of the side plate 414 of the housing 41 to the second chamber S2, and then flows into the first chamber S1 through the communication hole 461 of the partition plate 46. Here, the outdoor air that has passed through the communication hole 461 flows toward the fan 44. During the driving of the fan 44, the outdoor air flows from the first chamber S1 to the outside of the housing 41.

[0108] Since the second refrigerant is non-combustible, the risk during leakage is low. However, since the first refrigerant is combustible, if the first refrigerant flows toward the electrical component unit 420 (especially the electrical component 42) that becomes a fire source, there is a possibility of fire. The parts where the first refrigerant is likely to leak are the multiple welded parts of the first heat exchanger 12. In the present embodiment, the communication hole 461 is located above the uppermost first welded part 121 among the multiple welded parts 120. Therefore, even if the first refrigerant heavier than air leaks, it is possible to suppress the flow of the first refrigerant to a position above the communication hole 461.

[0109] In addition, during the driving of the fan 44, the outdoor air flowing from the communication hole 461 to the second chamber S2 is used to suppress the flow of the leaked first refrigerant to the second chamber S2.

[0110] Also, when the electrical component unit 420 (here, the electrical component 42) is located above as in the present embodiment, since the communication hole 461 is located above in the housing 41, the outdoor air flowing into the second chamber S2 passes around the electrical component unit 420 (here, the electrical component 42). Therefore, the outdoor air around the electrical component unit 420 (here, the electrical component 42) can be promoted to flow into the first chamber S1. Thereby, the leaked first refrigerant is suppressed from flowing around the electrical component 42.

[0111] Also, when the first refrigerant leaks, the first refrigerant above the lower end 451 of the cylindrical portion of the flare 45 is discharged to the outside of the housing 41 through the cylindrical portion of the flare 45 and the air outlet of the housing 41.

[0112] (4) Features

[0113] (4-1)

[0114] The outdoor unit 2 of the air conditioner unit according to the present embodiment includes an electrical component unit 420, a first heat exchanger 12, a second heat exchanger 23, a fan 44, a housing 41, and a partition plate 46. The first heat exchanger 12 exchanges heat between a combustible first refrigerant and air. The second heat exchanger 23 exchanges heat between a non-combustible second refrigerant and air. The fan 44 causes air to flow to the first heat exchanger 12 and the second heat exchanger 23. The housing 41 houses the electrical component unit 420, the first heat exchanger 12, the second heat exchanger 23, and the fan 44. The partition plate 46 divides the inside of the housing 41 into a first chamber S1 in which the first heat exchanger 12, the second heat exchanger 23, and the fan 44 are arranged, and a second chamber S2 in which the electrical component unit 420 is arranged. At a position above the partition plate 46 and above the uppermost first welding portion 121 among the plurality of welding portions 120 of the first heat exchanger 12, a communication hole 461 that connects the first chamber S1 and the second chamber S2 is provided.

[0115] In the outdoor unit 2 of the air conditioning unit according to the present embodiment, the air can flow from the second chamber S2 in which the electrical component unit 420 is disposed to the first chamber S1 in which the first heat exchanger 12 through which the first refrigerant flows is disposed, by the communication hole 461 provided in the partition plate 46 and the fan 44 disposed in the first chamber S1. Further, since the communication hole 461 is provided at a position P1 higher than the first welding portion 121 at the highest position P2 of the first heat exchanger 12 through which the flammable first refrigerant flows, even if the first refrigerant leaks in the first chamber S1, it is possible to suppress the first refrigerant from flowing to a position above the communication hole 461. Therefore, it is possible to reduce the possibility of ignition with the electrical component unit 420 in the second chamber S2 as the ignition source. Particularly in the case of a highly flammable (A3) refrigerant such as R290, this air conditioning unit is useful.

[0116] (4-2)

[0117] In the outdoor unit 2 of the air conditioning unit according to the present embodiment, in the outdoor unit 2 in the above (4-1), the communication hole 461 is a hole for guiding the air around the electrical component unit 420 to the fan.

[0118] Here, the air around the electrical component unit 420 that will become the ignition source is guided to the first chamber S1 through the communication hole 461. Therefore, even if the first refrigerant leaks, it is possible to suppress the first refrigerant from flowing around the electrical component unit 420.

[0119] (4-3)

[0120] In the outdoor unit 2 of the air conditioning unit according to the present embodiment, in the outdoor unit 2 in the above (4-1) or (4-2), a flare 45 is further provided. The flare 45 is disposed in the first chamber S1 and has a cylindrical portion surrounding the fan 44. The lower end 431 of the electrical component unit 420 is located at a position above the lower end 451 of the cylindrical portion.

[0121] Here, the fan 44 is disposed inside the cylindrical portion of the flare 45. Generally, the first refrigerant is heavier than air. Therefore, even if the first refrigerant leaks, the first refrigerant stays at a position below the lower end 451 of the cylindrical portion. In the present embodiment, since the lower end 431 of the electrical component unit 420 (specifically, the substrate 43 on which the electrical component 42 is mounted) is located at a position above the lower end 451 of the cylindrical portion, even if there is a gap between the lower end portion of the partition plate 46 and the bottom plate 413 of the housing 41 and the first refrigerant reaches the second chamber S2, it is possible to suppress the first refrigerant accumulated below from reaching the height level of the electrical component unit 420.

[0122] (4-4)

[0123] In the outdoor unit 2 of the air-conditioning unit according to the present embodiment, among any of the outdoor units 2 in the above (4-1) to (4-3), the electrical component unit 420 is located above the first welding portion 121.

[0124] Here, even when the first refrigerant leaks, the first refrigerant stays at a position below the first welding portion 121. Here, since the electrical component unit 420 is located above the first welding portion 121, the flow of the first refrigerant to the electrical components can be further suppressed.

[0125] (4-5)

[0126] In the outdoor unit 2 of the air-conditioning unit according to the present embodiment, among any of the outdoor units 2 in the above (4-1) to (4-4), the first heat exchanger 12 is located below the second heat exchanger 23.

[0127] Here, the first heat exchanger 12 through which the combustible refrigerant flows is arranged below the second heat exchanger 23 through which the non-combustible refrigerant flows. Therefore, even when the first refrigerant leaks, the first refrigerant easily stays below, and thus the distance between the communication hole 461 and the first welding portion 121 is maintained, so that the outdoor unit 2 capable of easily suppressing the flow of the first refrigerant to the electrical component unit 420 can be achieved.

[0128] (4-6)

[0129] In the outdoor unit 2 of the air-conditioning unit according to the present embodiment, among any of the outdoor units 2 in the above (4-1) to (4-5), the outdoor unit 2 further includes a first compressor 11, a second compressor 21, and a flare 45. The first compressor 11 is arranged in the second chamber S2 and compresses the first refrigerant. The second compressor 21 is arranged in the second chamber S2 and compresses the second refrigerant. The flare 45 is arranged in the first chamber S1 and has a cylindrical portion surrounding the fan 44. The first terminal 111 of the first compressor 11 and the second terminal 211 of the second compressor 21 are located above the lower end 451 of the cylindrical portion.

[0130] Here, even when the first refrigerant leaks, the first refrigerant stays at a position below the lower end 451 of the cylindrical portion of the flare 45. Here, since the first terminal 111 and the second terminal 211 are located above the lower end 451 of the cylindrical portion, the possibility of ignition with the first terminal 111 and the second terminal 211 in the second chamber S2 as the ignition source can be reduced.

[0131] (4-7)

[0132] In the outdoor unit 2 of the air conditioning unit according to the present embodiment, among any of the outdoor units 2 in the above (4-1) to (4-5), the second refrigerant contains carbon dioxide.

[0133] Since the carbon dioxide refrigerant has a low GWP (Global Warming Potential), it is possible to achieve an outdoor unit 2 that is more helpful in reducing global warming.

[0134] (5) Variations

[0135] (5-1) Variation 1

[0136] In the above embodiment, the air conditioning unit is the outdoor unit 2 of the binary refrigeration cycle device 1, but it is not limited thereto. The air conditioning unit of the present disclosure may also be an indoor unit or a cascade unit.

[0137] (5-2) Variation 2

[0138] In the above embodiment, the binary refrigeration cycle device 1 in which one indoor unit 3 is connected to one outdoor unit 2 has been described as an example, but it is not limited thereto. The binary refrigeration cycle device of this variation has a plurality of indoor units connected to one outdoor unit.

[0139] (5-3) Variation 3

[0140] In the above embodiment, the air conditioning unit of the binary refrigeration cycle device 1 that performs refrigeration operation and heating operation has been described as an example, but it is not limited thereto. The binary refrigeration cycle device equipped with the air conditioning unit of the present disclosure may also perform dehumidification operation. And, the binary refrigeration cycle device equipped with the air conditioning unit of the present disclosure may also be an air conditioning device dedicated to refrigeration.

[0141] The above describes the embodiments of the present disclosure, but it should be understood that various changes in the mode and details can be made without departing from the gist and scope of the present disclosure described in the claims.

[0142] Reference Numeral Explanation

[0143] 1: Binary refrigeration cycle device

[0144] 2: Outdoor unit (air conditioning unit)

[0145] 3: Indoor unit

[0146] 11: First compressor

[0147] 12: First heat exchanger

[0148] 21: Second compressor

[0149] 23: Second heat exchanger

[0150] 25: Third heat exchanger

[0151] 30: Cascade heat exchanger

[0152] 41: Outer shell

[0153] 42: Electrical component

[0154] 43: Substrate

[0155] 44: Fan

[0156] 45: Bellmouth

[0157] 46: Partition board

[0158] 111, 211: Terminal

[0159] 120: Welded part

[0160] 121: First welded part

[0161] 420: Electrical component unit

[0162] 431, 451: Lower end

[0163] 461: Communication hole

[0164] S1: First chamber

[0165] S2: Second chamber

[0166] Prior art documents

[0167] Patent documents

[0168] Patent Document 1: Japanese Patent No. 5430604

Claims

1. An air-conditioning unit (2), comprising: An electrical component unit (420); A first heat exchanger (12) that exchanges heat between a combustible first refrigerant and air; A second heat exchanger (23) that exchanges heat between a non-combustible second refrigerant and air; A fan (44) that causes air to flow to the first heat exchanger and the second heat exchanger; A housing (41) that houses the electrical component unit, the first heat exchanger, the second heat exchanger, and the fan; And A partition plate (46) that divides the interior of the housing into a first chamber (S1) in which the first heat exchanger, the second heat exchanger, and the fan are arranged, and a second chamber (S2) in which the electrical component unit is arranged. At a position above the first welding portion (121) which is the uppermost among a plurality of welding portions (120) of the first heat exchanger in the partition plate, a communication hole (461) that communicates the first chamber and the second chamber is provided.

2. The air-conditioning unit according to claim 1, wherein The communication hole is a hole for guiding air around the electrical component unit to the fan.

3. The air-conditioning unit according to claim 1 or 2, wherein The air-conditioning unit further includes a bell mouth (45), the bell mouth (45) is arranged in the first chamber and has a cylindrical portion surrounding the fan. The lower end (431) of the electrical component unit is located above the lower end (451) of the cylindrical portion.

4. The air-conditioning unit according to any one of claims 1 to 3, wherein The lower end (431) of the electrical component unit is located above the first welding portion.

5. The air-conditioning unit according to any one of claims 1 to 4, wherein The first heat exchanger is located below the second heat exchanger.

6. The air-conditioning unit according to any one of claims 1 to 5, wherein The air-conditioning unit further includes: A first compressor (11) that is arranged in the second chamber and compresses the first refrigerant; A second compressor (21) that is arranged in the second chamber and compresses the second refrigerant; And A bell mouth (45) that is arranged in the first chamber and has a cylindrical portion surrounding the fan. The terminals (111) of the first compressor and the terminals (211) of the second compressor are located above the lower end (451) of the cylindrical portion.

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