WO2024127924A1 - Air conditioning unit - Google Patents

Air conditioning unit Download PDF

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Publication number
WO2024127924A1
WO2024127924A1 PCT/JP2023/041728 JP2023041728W WO2024127924A1 WO 2024127924 A1 WO2024127924 A1 WO 2024127924A1 JP 2023041728 W JP2023041728 W JP 2023041728W WO 2024127924 A1 WO2024127924 A1 WO 2024127924A1
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WO
WIPO (PCT)
Prior art keywords
heat exchanger
refrigerant
chamber
unit
fan
Prior art date
Application number
PCT/JP2023/041728
Other languages
French (fr)
Japanese (ja)
Inventor
悠太 井吉
喜記 山野井
猛 宮崎
敦史 吉見
隼人 布
啓 竹中
賢吾 内田
翔太 東
浩彰 松田
Original Assignee
ダイキン工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ダイキン工業株式会社 filed Critical ダイキン工業株式会社
Priority to EP23864106.2A priority Critical patent/EP4407243A1/en
Publication of WO2024127924A1 publication Critical patent/WO2024127924A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/06—Separate outdoor units, e.g. outdoor unit to be linked to a separate room comprising a compressor and a heat exchanger
    • F24F1/20—Electric components for separate outdoor units
    • F24F1/24—Cooling of electric components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/06—Separate outdoor units, e.g. outdoor unit to be linked to a separate room comprising a compressor and a heat exchanger
    • F24F1/46—Component arrangements in separate outdoor units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/06—Separate outdoor units, e.g. outdoor unit to be linked to a separate room comprising a compressor and a heat exchanger
    • F24F1/46—Component arrangements in separate outdoor units
    • F24F1/48—Component arrangements in separate outdoor units characterised by air airflow, e.g. inlet or outlet airflow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B7/00—Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit

Definitions

  • Patent Document 1 Patent No. 5430604 discloses a cascade refrigeration system equipped with a low-stage refrigeration cycle that uses carbon dioxide refrigerant and a high-stage refrigeration cycle that assists the heat dissipation of the low-stage refrigeration cycle.
  • the high-stage evaporator and the low-stage condenser exchange heat in a cascade condenser, and the auxiliary radiator installed in the front stage of the low-stage refrigeration cycle of the cascade condenser and the high-stage condenser are integrated to form an integrated radiator.
  • Patent Document 1 discloses that HC refrigerants, HFC refrigerants, HFO refrigerants, etc. are used in the high-temperature refrigeration cycle. If a flammable refrigerant leaks from the high-temperature condenser, there is a possibility that the electrical equipment unit may become an ignition source and cause a fire.
  • the air conditioning unit of the first aspect includes an electrical equipment unit, a first heat exchanger, a second heat exchanger, a fan, a casing, 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 flows air through the first heat exchanger and the second heat exchanger.
  • the casing houses the electrical equipment unit, the first heat exchanger, the second heat exchanger, and the fan.
  • the partition plate divides the inside of the casing 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 equipment unit is arranged.
  • the partition plate has a communication hole that communicates between the first chamber and the second chamber, above the first brazed portion that is located at the top of the multiple brazed portions of the first heat exchanger.
  • the communication hole provided in the partition plate and the fan disposed in the first chamber allow air to flow from the second chamber in which the electrical equipment unit is disposed to the first chamber in which the first heat exchanger through which the first refrigerant flows is disposed. Furthermore, since the communication hole is provided at a position higher than the first brazed portion, which is at the highest position of the first heat exchanger through which the flammable first refrigerant flows, even if the first refrigerant leaks in the first chamber, the first refrigerant can be prevented from flowing above the communication hole. This reduces the possibility of a fire caused by the electrical equipment unit in the second chamber as an ignition source.
  • the air conditioning unit of the second aspect is the air conditioning unit of the first aspect, and the communication hole is a hole for directing air around the electrical equipment unit to the fan.
  • the air around the electrical equipment unit which is a potential ignition source, is directed into the first chamber, so that even if the first refrigerant leaks, the first refrigerant can be prevented from flowing around the electrical equipment unit.
  • the air conditioning unit of the third aspect is the air conditioning unit of the first or second aspect, further comprising a bell mouth.
  • the bell mouth is disposed in the first chamber and has a cylindrical portion surrounding the fan.
  • the lower end of the electrical equipment unit is located above the lower end of the cylindrical portion.
  • a fan is placed inside the cylindrical portion of the bellmouth.
  • the first refrigerant is heavier than air, so even if the first refrigerant leaks, the first refrigerant will accumulate below the bottom end of the cylindrical portion.
  • the bottom end of the board on which the electrical equipment unit is mounted is located above the bottom end of the cylindrical portion, so the first refrigerant can be further prevented from flowing into the electrical equipment unit.
  • the air conditioning unit of the fourth aspect is an air conditioning unit of any one of the first to third aspects, in which the lower end of the electrical equipment unit is located above the first brazed portion.
  • the air conditioning unit of the fourth aspect even if the first refrigerant leaks, the first refrigerant will remain below the first brazed portion.
  • the lower end of the board on which the electrical equipment unit is mounted is located above the first brazed portion, so that the first refrigerant can be further prevented from flowing into the electrical equipment unit.
  • the fifth aspect of the air conditioning unit is an air conditioning unit according to any one of the first to fourth aspects, in which the first heat exchanger is positioned lower than the second heat exchanger.
  • the first heat exchanger through which the flammable refrigerant flows is disposed below the second heat exchanger through which the non-flammable refrigerant flows. Therefore, even if the first refrigerant leaks, the first refrigerant tends to accumulate below, making it easy to realize an air conditioning unit that prevents the first refrigerant from flowing into the electrical equipment unit.
  • the air conditioning unit of a sixth aspect is the air conditioning unit of any one of the first aspect to the fifth aspect, further comprising a first compressor, a second compressor, and a bell mouth.
  • the first compressor is disposed in the second chamber and compresses a first refrigerant.
  • the second compressor is disposed in the second chamber and compresses a second refrigerant.
  • the bell mouth is disposed in the first chamber and has a cylindrical portion surrounding the fan. The terminal of the first compressor and the terminal of the second compressor are located above the lower end of the cylindrical portion.
  • the first refrigerant remains below the lower end of the cylindrical portion of the bellmouth.
  • the terminal is located above the lower end of the cylindrical portion, which reduces the possibility of a fire caused by the terminal of the second chamber as an ignition source.
  • FIG. 1 is a schematic configuration diagram of a dual cascade refrigeration cycle device including an outdoor unit according to an embodiment of the present disclosure.
  • FIG. 2 is a schematic cross-sectional view of the outdoor unit.
  • FIG. 2 is a schematic plan view of the outdoor unit.
  • FIG. 4 is a diagram showing the operation of the cascade refrigeration cycle device in cooling operation.
  • FIG. 4 is a diagram showing the operation of the cascade refrigeration cycle device in heating operation.
  • FIG. 4 is a diagram showing a plurality of brazed portions.
  • a cascade refrigeration cycle apparatus 1 employing an outdoor unit 2 is an apparatus used for cooling and heating the interior of a building or the like by performing a vapor compression refrigeration cycle operation.
  • the cascade refrigeration cycle device 1 has a first cycle 10 and a second cycle 20.
  • the cascade refrigeration cycle device 1 of this embodiment has a binary refrigerant circuit consisting of a vapor compression type first cycle 10 and a vapor compression type second cycle 20, and performs a binary refrigeration cycle.
  • a combustible first refrigerant circulates.
  • the first refrigerant has a critical point of, for example, 40°C or higher.
  • the first refrigerant is, for example, a hydrocarbon refrigerant such as R1234yf, R1234ze, or R32, and in this embodiment, is R290.
  • the specific gravity of the first refrigerant is greater than that of air.
  • the second cycle 20 circulates a non-flammable second refrigerant.
  • the second refrigerant has a critical point of, for example, less than 40°C.
  • the second refrigerant includes, for example, carbon dioxide, and in this embodiment, the second refrigerant is a single refrigerant of carbon dioxide.
  • the first cycle 10 and the second cycle 20 are thermally connected via a cascade heat exchanger 30.
  • the cascade refrigeration cycle system 1 comprises an outdoor unit 2 and an indoor unit 3.
  • the outdoor unit 2 and the indoor unit 3 are connected to each other via interconnecting pipes 4 and 5.
  • the first cycle 10 constitutes a subcooling circuit during cooling 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.
  • the first compressor 11 is a device for compressing the first refrigerant, and is, for example, a volumetric compressor such as a scroll type whose operating capacity can be varied by inverter controlling the compressor motor.
  • the first compressor 11 has a first terminal 111.
  • a power supply wiring is connected to the first terminal 111.
  • the first terminal 111 is a harness connection portion.
  • the first heat exchanger 12 is a device for exchanging heat between the first refrigerant and the outdoor air.
  • the first refrigerant obtains cold or hot heat from the outdoor air.
  • the first heat exchanger 12 is, for example, a fin-and-tube type heat exchanger made up of a large number of heat transfer tubes and fins.
  • the first expansion mechanism 13 is a device that reduces the pressure of the first refrigerant, and is, for example, an electric expansion valve.
  • the cascade heat exchanger 30 is a device for performing heat exchange between a first refrigerant and a second refrigerant without mixing them.
  • the cascade heat exchanger 30 is, 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 is connected to the first expansion mechanism 13.
  • the cascade heat exchanger 30 is intended to supercool the second refrigerant cooled by the second heat exchanger 23, and serves as an assistant to the second cycle 20.
  • 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.
  • the second compressor 21 is a device for compressing the second refrigerant, and is, for example, a scroll type or other positive displacement compressor whose operating capacity can be varied by inverter controlling the compressor motor.
  • the second compressor 21 has a second terminal 211.
  • a power supply wiring is connected to the second terminal 211.
  • the second terminal 211 is a harness connection portion.
  • the switching mechanism 22 is a device that switches between a first state (see the solid line of the switching mechanism 22 in Figure 1) 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, and a second state (see the dashed line of the switching mechanism 22 in Figure 1) 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.
  • the switching mechanism 22 is, for example, a four-way switching valve.
  • 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.
  • the switching mechanism 22 connects the discharge side of the second compressor 21 to the gas side of the third heat exchanger 25, and also connects the suction side of the second compressor 21 to the gas side of the second heat exchanger 23.
  • the second heat exchanger 23 is a device for exchanging heat between the second refrigerant and the outdoor air.
  • the second refrigerant obtains cold or hot heat from the outdoor air.
  • the second heat exchanger 23 is, for example, a fin-and-tube type heat exchanger made up of a large number of heat transfer tubes and fins.
  • the second cycle 20 has a second flow path 32 of the cascade heat exchanger 30.
  • the gas side of the second flow path 32 is connected to the second heat exchanger 23, and the liquid side is connected to the third heat exchanger 25.
  • the second expansion mechanism 24 is a device that reduces the pressure of the second refrigerant, and is, for example, an electric expansion valve.
  • the third heat exchanger 25 is a device for exchanging heat between the second refrigerant and the indoor air, and is, for example, a fin-and-tube type heat exchanger made up of a large number of heat transfer tubes and fins.
  • the outdoor unit 2 is placed in a space different from the space in which the indoor unit 3 is placed.
  • the outdoor unit 2 is installed outdoors (on the roof of a building, near the exterior wall of a building, etc.).
  • the outdoor unit 2 has the above-mentioned first cycle 10, a part of the second cycle 20, a casing 41, an electrical equipment unit 420 including electrical equipment 42 and a board 43, a fan 44, a bell mouth 45, a partition plate 46, and a refrigerant leakage sensor 47.
  • the outdoor unit 2 has the first compressor 11, first heat exchanger 12, first expansion mechanism 13, second compressor 21, switching mechanism 22, second heat exchanger 23, second expansion mechanism 24, cascade heat exchanger 30 shown in FIG. 1, and the casing 41, electrical equipment 42, board 43, fan 44, bell mouth 45, partition plate 46, and refrigerant leakage sensor 47 shown in FIG. 2.
  • the casing 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 electrical components 42, the circuit board 43, the fan 44, the bell mouth 45, the partition plate 46, and the refrigerant leakage sensor 47.
  • the casing 41 shown in FIG. 2 has a generally rectangular parallelepiped shape. Specifically, the casing 41 includes a front plate 411, a top plate 412, a bottom plate 413, and side plates 414.
  • the front plate 411 is a plate-like member that forms the front surface of the casing 41.
  • An air outlet is formed in the front plate 411.
  • the air outlet is an opening for blowing the outdoor air that has been taken in from the outside of the casing 41 to the inside of the casing 41 out to the outside of the casing 41.
  • the top plate 412 is a plate-like member that forms the upper surface of the casing 41.
  • the bottom plate 413 is a plate-like member that forms the lower surface of the casing 41.
  • the top plate 412 and the bottom plate 413 face each other.
  • the side plate 414 is a plate-like member that forms the side surface of the casing 41.
  • the lower portion of the side plate 414 is fixed to the bottom plate 413.
  • the casing 41 has an opening 415 for allowing outside air to flow to the communication hole 461 of the partition plate 46 described below.
  • the opening 415 is formed in the side plate 414 that partitions the second chamber S2 described below. Note that the opening 415 does not necessarily have to be formed in the side plate 414, and can be provided in any member that partitions the second chamber S2 from the outside of the casing 41.
  • the electrical equipment unit 420 has electrical equipment 42 (electrical components) mounted on a board 43.
  • the electrical equipment 42 controls the controlled objects such as the first compressor 11, the second compressor 21, the first expansion mechanism 13, the switching mechanism 22, and the second expansion mechanism 24.
  • the electrical equipment 42 includes, for example, cooled elements such as power elements, reactors, capacitors, wiring connections, etc.
  • the board 43 is, for example, a printed circuit board.
  • the board 43 extends in the vertical direction.
  • multiple electrical components 42 are attached to the board 43.
  • the fan 44 directs air to the first heat exchanger 12 and the second heat exchanger 23.
  • the fan 44 directs outdoor air to both the first heat exchanger 12 and the second heat exchanger 23.
  • the fan 44 guides the outdoor air to the first heat exchanger 12 and the second heat exchanger 23, where the outdoor air is heat exchanged with the first refrigerant flowing through the first heat exchanger 12 and with the second refrigerant flowing through the second heat exchanger 23, and then discharged to the outside.
  • the fan 44 is driven by a fan motor. Note that the fan that directs air to the first heat exchanger 12 and the fan that directs air to the second heat exchanger 23 may be provided separately.
  • the bellmouth 45 is disposed on the blowing side of the fan 44.
  • the bellmouth 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.
  • the fan 44 and the bellmouth 45 overlap the first heat exchanger 12 and the second heat exchanger 23.
  • the bellmouth 45 faces an air outlet (not shown) formed in the front plate 411 of the casing 41.
  • the refrigerant leakage sensor 47 detects leakage of the first refrigerant.
  • the refrigerant leakage sensor 47 is installed at the bottom inside the casing 41.
  • the refrigerant leakage sensor 47 may also detect leakage of the second refrigerant.
  • the partition plate 46 is a plate-shaped member that extends in the vertical direction. The lower part of the partition plate 46 is fixed to the bottom plate 413 of the casing 41.
  • the partition plate 46 divides the inside of the casing 41 into a first chamber S1 and a second chamber S2.
  • the first chamber S1 and the second chamber S2 are each a space defined by the front plate 411, the top plate 412, the bottom plate 413, and the side plates 414 of the casing 41 and the partition plate 46.
  • the first chamber S1 is an air blowing chamber, and is an air guide passage through which air drawn in from the air intake of the outdoor unit 2 flows to the air outlet.
  • the second chamber S2 is a machine room.
  • the first heat exchanger 12, the second heat exchanger 23, the fan 44, and the bell mouth 45 are arranged in the first chamber S1.
  • the second chamber S2 is arranged with the first compressor 11, the second compressor 21, the switching mechanism 22, the first expansion mechanism 13, the second expansion mechanism 24, the electrical equipment unit 420 including the electrical equipment 42 and the board 43, and the refrigerant leakage sensor 47.
  • the partition plate 46 has a communication hole 461. As shown in FIG. 5, the communication hole 461 is provided above the first brazed portion 121, which is the uppermost of the multiple brazed portions 120 of the first heat exchanger 12.
  • the brazed portions 120 are portions in the first chamber S1 where the first refrigerant may leak from the first heat exchanger 12.
  • the brazed portions 120 are joints between the heat transfer tubes that make up the first heat exchanger 12, joints between the heat transfer tubes and the fins, etc.
  • Heat transfer tubes include U-shaped tubes and branch tubes.
  • the multiple brazed portions 120 are joints between hairpin-shaped tubes and U-shaped tubes or branch tubes.
  • the brazed portions also become brazed portions.
  • the vertical height position of the communication hole 461 is indicated by P1
  • the vertical height position of the first brazed portion 121 is indicated by P2.
  • the vertical height position P1 of the communication hole 461 is the lowest end of the communication hole 461. Therefore, the height position P1 of the lowest end of the communication hole 461 is higher than the vertical height position of the first brazed portion 121.
  • the communication hole 461 is a hole for guiding the outside air that flows into the second chamber S2 from the opening 415 of the casing 41 to the first chamber S1.
  • the communication hole 461 is a hole for guiding the air around the electrical component unit 420, which includes the electrical components 42 and the board 43, to the fan 44.
  • the communication hole 461 is a hole for guiding the outside air around the electrical component unit 420, which includes the electrical components 42 and the board 43 in the second chamber S2, to the fan 44 in the first chamber S1.
  • the communication hole 461 is located above the upper end of the first heat exchanger 12. Also, the height position P1 of the communication hole 461 overlaps with the second heat exchanger 23.
  • the communication hole 461 is located above the lower end 451 of the cylindrical portion of the bell mouth 45.
  • 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.
  • the communication hole 461 is located above the lower end 431 of the electrical equipment unit 420 (here, the board 43).
  • the height position P1 of the lowest end of the communication hole 461 is located above the electrical equipment 42 that is located at the lowest among the multiple electrical equipment 42.
  • the first heat exchanger 12 is located below the second heat exchanger 23. In other words, at least a portion of the first heat exchanger 12 is located below the second heat exchanger 23. The entire first heat exchanger 12 may be located below the second heat exchanger 23, or a portion of the first heat exchanger 12 may be located below the second heat exchanger 23.
  • the first heat exchanger 12 and the second heat exchanger 23 may be separate or integrated.
  • the size of the first heat exchanger 12 may be approximately the same as the size of the second heat exchanger 23, and may be smaller in the vertical height direction.
  • the electrical equipment unit 420 including the electrical equipment 42 and the circuit board 43 is disposed above the first compressor 11 and the second compressor 21.
  • the lower end 431 of the electrical equipment unit 420 (here, the board 43) is located above the lower end 451 of the cylindrical portion of the bellmouth 45.
  • the vertical height position of the lower end 431 of the electrical equipment unit 420 (here, the board 43 to which the electrical equipment 42 is attached) is higher than the opening lower end 451 of the bellmouth 45, which is located on the blowing side of the fan 44.
  • the lowest electrical component 42 among the multiple electrical components 42 is located above the lower end 451 of the cylindrical portion of the bellmouth 45.
  • the lower end 431 of the electrical component unit 420 (here, the board 43) is located above the first brazing portion 121.
  • the height position of the electrical component unit 420 (here, the board 43 to which the electrical components 42 are attached) is above the height position P1 of the first brazing portion 121.
  • the electrical component 42 located at the lowest position among the multiple electrical components 42 is located above the first brazing portion 121.
  • 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.
  • the lower end of the first terminal 111 of the first compressor 11 and the lower end of 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.
  • the indoor unit 3 is installed indoors (inside the building). As described above, the indoor unit 3 is connected to the outdoor unit 2 via the connecting pipes 4 and 5, and constitutes a part of the second cycle 20.
  • the indoor unit 3 has a third heat exchanger 25.
  • the indoor unit 3 is installed by embedding or hanging in the ceiling of a room of a building or the like, or by hanging on a wall surface of the room.
  • the communication pipes 4, 5 are refrigerant pipes that are installed on-site when the cascade refrigeration cycle apparatus 1 is installed in an installation location such as a building.
  • One end of the liquid side communication pipe 4 is connected to the liquid side end of the outdoor unit 2, and the other end of the communication 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 communication pipe 5 is connected to the gas side end of the outdoor unit 2, and the other end of the communication pipe 5 is connected to the gas side end of the third heat exchanger 25 of the indoor unit 3.
  • Control Unit The components of the outdoor unit 2 and the indoor unit 3 are controlled by the control unit 6.
  • the control unit 6 is configured by communication connection between the electrical equipment 42, the board 43, etc. provided in the outdoor unit 2 and the control board, etc. (not shown) provided in the indoor unit 3.
  • the control unit 6 is illustrated in FIG. 1 at a position separate from the outdoor unit 2 and the indoor unit 3.
  • the control unit 6 controls the components of the cascade refrigeration cycle apparatus 1 (here, the outdoor unit 2 and the indoor unit 3). In other words, the control unit 6 controls the operation of the entire cascade refrigeration cycle apparatus 1.
  • the control unit 6 is realized by a computer.
  • the control unit 6 includes a control arithmetic unit and a storage device.
  • the control arithmetic unit can be a processor such as a CPU or a GPU.
  • the control arithmetic unit reads a program stored in the storage device, and performs predetermined image processing and arithmetic processing according to the program. Furthermore, the control arithmetic unit can write the results of calculations to the storage device and read information stored in the storage device according to the program.
  • the operation of the cascade refrigeration cycle device 1 will be described with reference to Figures 1 to 4.
  • the cascade refrigeration cycle device 1 is capable of performing a cooling operation for cooling indoor air and a heating operation for heating indoor air for air conditioning. In the cooling operation and the heating operation, the operation of the cascade refrigeration cycle device 1 is controlled by the control unit 6.
  • the second refrigerant discharged from the second compressor 21 is sent to the second heat exchanger 23 through the switching mechanism 22.
  • the second refrigerant sent to the second heat exchanger 23 is cooled by exchanging heat with the outdoor air supplied by the fan 44, thereby releasing heat.
  • the second refrigerant that has released heat in the second heat exchanger 23 is sent to the second flow path 32 of the cascade heat exchanger 30.
  • the second refrigerant sent to the second flow path 32 is further cooled in the cascade heat exchanger 30 by exchanging heat with the first refrigerant flowing through the first flow path 31.
  • the second refrigerant that has been further cooled in the cascade heat exchanger 30 is depressurized by the second expansion mechanism 24 and then flows out of the outdoor unit 2.
  • the second refrigerant that flows out of the outdoor unit 2 flows into the indoor unit 3 via the liquid side connecting pipe 4.
  • the second refrigerant is sent to the third heat exchanger 25.
  • the second refrigerant sent to the third heat exchanger 25 evaporates by being heated through heat exchange with the indoor air.
  • the second refrigerant that has evaporated in the third heat exchanger 25 flows out of the indoor unit 3.
  • the second refrigerant that flows out of the indoor unit 3 flows into the outdoor unit 2 via the gas side connecting pipe 5.
  • the second refrigerant is sucked back into the second compressor 21 via the switching mechanism 22.
  • the first refrigerant discharged from the first compressor 11 is sent to the first heat exchanger 12.
  • the first refrigerant sent to the first heat exchanger 12 is cooled and condensed by heat exchange with the outdoor air supplied by the fan 44.
  • the first refrigerant condensed in the first heat exchanger 12 is depressurized by the first expansion mechanism 13 and then sent to the first flow path 31 of the cascade heat exchanger 30.
  • the first refrigerant sent to the first flow path 31 is heated in the cascade heat exchanger 30 by heat exchange with the second refrigerant flowing in the second flow path 32, and evaporates.
  • the first refrigerant evaporated in the cascade heat exchanger 30 is sucked back into the first compressor 11.
  • the switching mechanism 22 is switched to the second state (the state in which the switching mechanism 22 is in the broken line) so that the second heat exchanger 23 functions as an evaporator of the second refrigerant and the third heat exchanger 25 functions as a radiator of the second refrigerant. Also, during heating operation, the first compressor 11 is not started, and the first refrigerant is not circulated in the first cycle 10.
  • the second refrigerant discharged from the second compressor 21 flows out of the outdoor unit 2 through the switching mechanism 22.
  • the refrigerant flowing out of the outdoor unit 2 flows into the indoor unit 3 via the gas side connecting pipe 5.
  • the second refrigerant is sent to the third heat exchanger 25.
  • the second refrigerant sent to the third heat exchanger 25 exchanges heat with the indoor air and is cooled, thereby releasing heat.
  • the second refrigerant that has released heat in the third heat exchanger 25 flows out of the indoor unit 3.
  • the second refrigerant flowing out of the indoor unit 3 flows into the outdoor unit 2 via the liquid side connecting pipe 4.
  • the second refrigerant is sent 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 sent to the second heat exchanger 23 evaporates by being heated through heat exchange with the outdoor air supplied by the fan 44.
  • the second refrigerant evaporated in the second heat exchanger 23 is sucked back into the second compressor 21 through the switching mechanism 22.
  • the second refrigerant is non-flammable, so there is little risk if it leaks, but the first refrigerant is flammable, so there is a risk of fire if the first refrigerant flows into the electrical equipment unit 420 (particularly the electrical equipment 42), which is a source of ignition.
  • the locations where the first refrigerant is most likely to leak are the multiple brazed parts of the first heat exchanger 12.
  • the communication hole 461 is located above the first brazed part 121, which is the uppermost of the multiple brazed parts 120, so that even if the first refrigerant, which is heavier than air, leaks, the first refrigerant is prevented from flowing above the communication hole 461.
  • the communication hole 461 is located at the top inside the casing 41, so that the outside air that flows into the second chamber S2 passes around the electrical equipment unit 420 (electrical equipment 42 in this case). This can promote the flow of the outside air around the electrical equipment unit 420 (electrical equipment 42 in this case) into the first chamber S1. This prevents the leaked first refrigerant from flowing around the electrical equipment 42.
  • the first refrigerant above the lower end 451 of the cylindrical portion of the bell mouth 45 passes through the cylindrical portion of the bell mouth 45 and the outlet of the casing 41 and is discharged outside the casing 41.
  • the outdoor unit 2 as an air conditioning unit includes an electrical equipment 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 passes air through the first heat exchanger 12 and the second heat exchanger 23.
  • the casing 41 houses the electrical equipment 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 casing 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 equipment unit 420 is arranged.
  • the partition plate 46 has a communication hole 461 that connects the first chamber S1 and the second chamber S2 above the first brazed portion 121, which is the uppermost of the multiple brazed portions 120 of the first heat exchanger 12.
  • the communication hole 461 provided in the partition plate 46 and the fan 44 provided in the first chamber S1 allow air to flow from the second chamber S2 in which the electrical equipment unit 420 is arranged to the first chamber S1 in which the first heat exchanger 12 through which the first refrigerant flows is arranged.
  • the communication hole 461 is provided at a position P1 higher than the first brazed portion 121 at the highest position P2 of the first heat exchanger 12 through which the flammable first refrigerant flows, so that even if the first refrigerant leaks in the first chamber S1, the first refrigerant can be prevented from flowing above the communication hole 461. Therefore, the possibility of ignition caused by the electrical equipment unit 420 in the second chamber S2 as an ignition source can be reduced.
  • This air conditioning unit is particularly useful in the case of a highly flammable (A3) refrigerant such as R290.
  • the outdoor unit 2 as an air conditioning unit according to this embodiment is the outdoor unit 2 described above in (4-1), and the communication hole 461 is a hole for guiding air around the electrical component unit 420 to the fan.
  • the air around the electrical equipment unit 420 which is a potential ignition source, is guided to the first chamber S1 through the communication hole 461, so that even if the first refrigerant leaks, the first refrigerant is prevented from flowing around the electrical equipment unit 420.
  • the outdoor unit 2 as an air conditioning unit according to this embodiment is the outdoor unit 2 of (4-1) or (4-2) above, and further includes a bellmouth 45.
  • the bellmouth 45 is disposed in the first chamber S1, and has a cylindrical portion surrounding the fan 44.
  • a lower end 431 of the electrical component unit 420 is located above a lower end 451 of the cylindrical portion.
  • the fan 44 is disposed inside the cylindrical portion of the bellmouth 45.
  • the first refrigerant is heavier than air, so even if the first refrigerant leaks, the first refrigerant will accumulate below the lower end 451 of the cylindrical portion.
  • the lower end 431 of the electrical equipment unit 420 (specifically, the board 43 on which the electrical equipment 42 is mounted) is located above the lower end 451 of the cylindrical portion, so that even if there is a gap between the lower end of the partition plate 46 and the bottom plate 413 of the casing 41 and the first refrigerant goes into the second chamber S2, the first refrigerant accumulated below can be prevented from reaching the height level of the electrical equipment unit 420.
  • the outdoor unit 2 serving as an air conditioning unit according to this embodiment is any one of the outdoor units 2 described above in (4-1) to (4-3), in which the electrical component unit 420 is positioned above the first brazed portion 121.
  • the first refrigerant even if the first refrigerant leaks, the first refrigerant will remain below the first brazed portion 121.
  • the electrical equipment unit 420 is located above the first brazed portion 121, the first refrigerant can be further prevented from flowing to the electrical equipment.
  • the outdoor unit 2 as an air conditioning unit according to this embodiment is any one of the outdoor units 2 described above in (4-1) to (4-4), in which the first heat exchanger 12 is positioned below the second heat exchanger 23.
  • the first heat exchanger 12, through which the flammable refrigerant flows, is positioned below the second heat exchanger 23, through which the non-flammable refrigerant flows. Therefore, even if the first refrigerant leaks, the first refrigerant is likely to remain below, and since a distance can be maintained between the communication hole 461 and the first brazed portion 121, an outdoor unit 2 that prevents the first refrigerant from flowing into the electrical equipment unit 420 can be easily realized.
  • the outdoor unit 2 as an air conditioning unit is the outdoor unit 2 according to any one of (4-1) to (4-5) above, and further includes a first compressor 11, a second compressor 21, and a bell mouth 45.
  • the first compressor 11 is disposed in the second chamber S2 and compresses a first refrigerant.
  • the second compressor 21 is disposed in the second chamber S2 and compresses a second refrigerant.
  • the bell mouth 45 is disposed 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 a lower end 451 of the cylindrical portion.
  • the first terminal 111 and the second terminal 211 are located above the lower end 451 of the cylindrical portion, so the possibility of ignition caused by the first terminal 111 and the second terminal 211 of the second chamber S2 as an ignition source can be reduced.
  • the outdoor unit 2 as an air conditioning unit according to this embodiment is any one of the outdoor units 2 described above in (4-1) to (4-5), and the second refrigerant contains carbon dioxide.
  • the air conditioning unit is the outdoor unit 2 of the cascade refrigeration cycle apparatus 1, but is not limited thereto.
  • the air conditioning unit of the present disclosure may be an indoor unit or a cascade unit.
  • the air conditioning unit of the cascade refrigeration cycle apparatus 1 performing cooling operation and heating operation has been described as an example, but the present invention is not limited thereto.
  • the cascade refrigeration cycle apparatus including the air conditioning unit of the present disclosure may further perform a dehumidification operation.
  • the cascade refrigeration cycle apparatus including the air conditioning unit of the present disclosure may be an air conditioner dedicated to cooling.
  • Dual refrigeration cycle device 2 Outdoor unit (air conditioning unit) 3: Indoor unit 11: First compressor 12: First heat exchanger 21: Second compressor 23: Second heat exchanger 25: Third heat exchanger 30: Cascade heat exchanger 41: Casing 42: Electrical components 43: Board 44: Fan 45: Bell mouth 46: Partition plate 111, 211: Terminal 120: Brazed portion 121: First brazed portion 420: Electrical component unit 431, 451: Lower end 461: Communication hole S1: First chamber S2: Second chamber

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Abstract

This air conditioning unit comprises an electrical 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) carries out heat exchange between a combustible first medium and air. The second heat exchanger (23) carries out heat exchange between a non-combustible second medium and air. The fan (44) sends air to the first heat exchanger (12) and second heat exchanger (23). The partition plate (46) partitions the interior of the casing (41) into a first chamber (S1) where the first heat exchanger (12), second heat exchanger (23), and fan (44) are positioned and a second chamber (S2) where the electrical component unit (420) is positioned. A communication hole (461) via which the first chamber (S1) and second chamber (S2) communicated is provided to the partition plate (46) at a location higher than an uppermost-positioned first brazing part (121) among a plurality of brazing parts (120) of the first heat exchanger (12).

Description

空調ユニットAir conditioning unit
　空調ユニットに関する。 Regarding air conditioning units.
　特許文献１（特許第５４３０６０４号）には、二酸化炭素冷媒を用いた低元冷凍サイクルと、低元冷凍サイクルの放熱を補助する高元冷凍サイクルと、を備える二元冷凍装置が開示されている。特許文献１の二元冷凍装置では、高元側蒸発器と低元側凝縮器とがカスケードコンデンサで熱交換し、カスケードコンデンサの低元冷凍サイクルにおける前段に設置された補助放熱器及び高元側凝縮器が一体化されて一体型放熱器を構成している。 Patent Document 1 (Patent No. 5430604) discloses a cascade refrigeration system equipped with a low-stage refrigeration cycle that uses carbon dioxide refrigerant and a high-stage refrigeration cycle that assists the heat dissipation of the low-stage refrigeration cycle. In the cascade refrigeration system of Patent Document 1, the high-stage evaporator and the low-stage condenser exchange heat in a cascade condenser, and the auxiliary radiator installed in the front stage of the low-stage refrigeration cycle of the cascade condenser and the high-stage condenser are integrated to form an integrated radiator.
　しかしながら、上記特許文献１において、高元冷凍サイクルには、ＨＣ系冷媒、ＨＦＣ冷媒、ＨＦＯ冷媒等を用いることが開示されている。高元側凝縮器から可燃性の冷媒が漏洩すると、電装品ユニットを着火源として発火する可能性がある。 However, the above-mentioned Patent Document 1 discloses that HC refrigerants, HFC refrigerants, HFO refrigerants, etc. are used in the high-temperature refrigeration cycle. If a flammable refrigerant leaks from the high-temperature condenser, there is a possibility that the electrical equipment unit may become an ignition source and cause a fire.
　第１観点の空調ユニットは、電装品ユニットと、第１熱交換器と、第２熱交換器と、ファンと、ケーシングと、仕切板と、を備える。第１熱交換器は、燃焼性の第１冷媒と、空気とを熱交換させる。第２熱交換器は、非燃焼性の第２冷媒と、空気とを熱交換させる。ファンは、第１熱交換器及び第２熱交換器に空気を流す。ケーシングは、電装品ユニット、第１熱交換器、第２熱交換器及びファンを収容する。仕切板は、ケーシング内を、第１熱交換器、第２熱交換器及びファンが配置される第１室と、電装品ユニットが配置される第２室と、に仕切る。仕切板には、第１熱交換器の複数のロウ付け部のうち最も上方に位置する第１ロウ付け部よりも上方に、第１室と第２室とを連通させる連通孔が設けられている。 The air conditioning unit of the first aspect includes an electrical equipment unit, a first heat exchanger, a second heat exchanger, a fan, a casing, 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 flows air through the first heat exchanger and the second heat exchanger. The casing houses the electrical equipment unit, the first heat exchanger, the second heat exchanger, and the fan. The partition plate divides the inside of the casing 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 equipment unit is arranged. The partition plate has a communication hole that communicates between the first chamber and the second chamber, above the first brazed portion that is located at the top of the multiple brazed portions of the first heat exchanger.
　第１観点の空調ユニットでは、仕切板に設けられた連通孔及び第１室に配置されたファンにより、電装品ユニットが配置される第２室から、第１冷媒が流れる第１熱交換器が配置される第１室に空気を流すことができる。そして、燃焼性の第１冷媒が流れる第１熱交換器の最も高い位置にある第１ロウ付け部よりも高い位置に連通孔が設けられているので、第１室で第１冷媒が漏洩した場合であっても、連通孔よりも上方に第１冷媒が流れることを抑制できる。したがって、第２室の電装品ユニットを着火源とした発火の可能性を減らすことができる。 In the air conditioning unit of the first aspect, the communication hole provided in the partition plate and the fan disposed in the first chamber allow air to flow from the second chamber in which the electrical equipment unit is disposed to the first chamber in which the first heat exchanger through which the first refrigerant flows is disposed. Furthermore, since the communication hole is provided at a position higher than the first brazed portion, which is at the highest position of the first heat exchanger through which the flammable first refrigerant flows, even if the first refrigerant leaks in the first chamber, the first refrigerant can be prevented from flowing above the communication hole. This reduces the possibility of a fire caused by the electrical equipment unit in the second chamber as an ignition source.
　第２観点の空調ユニットは、第１観点の空調ユニットであって、連通孔は、電装品ユニット周りの空気をファンへ導くための孔である。 The air conditioning unit of the second aspect is the air conditioning unit of the first aspect, and the communication hole is a hole for directing air around the electrical equipment unit to the fan.
　第２観点の空調ユニットでは、着火源となる電装品ユニット周りの空気を、第１室に導くので、第１冷媒が漏洩した場合であっても、電装品ユニット周りに第１冷媒が流れることを抑制できる。 In the air conditioning unit of the second aspect, the air around the electrical equipment unit, which is a potential ignition source, is directed into the first chamber, so that even if the first refrigerant leaks, the first refrigerant can be prevented from flowing around the electrical equipment unit.
　第３観点の空調ユニットは、第１観点または第２観点の空調ユニットであって、ベルマウスをさらに備える。ベルマウスは、第１室に配置され、ファンを囲む筒状部を有する。電装品ユニットの下端は、筒状部の下端よりも上方に位置する。 The air conditioning unit of the third aspect is the air conditioning unit of the first or second aspect, further comprising a bell mouth. The bell mouth is disposed in the first chamber and has a cylindrical portion surrounding the fan. The lower end of the electrical equipment unit is located above the lower end of the cylindrical portion.
　第３観点の空調ユニットでは、ベルマウスの筒状部の内側にファンが配置される。通常、第１冷媒は、空気よりも重いので、第１冷媒が漏洩した場合であっても、第１冷媒は筒状部の下端よりも下方に滞留する。ここでは、電装品ユニットが取り付けられる基板の下端が筒状部の下端よりも上方に位置しているので、第１冷媒が電装品ユニットに流れることをより抑制できる。 In the air conditioning unit of the third aspect, a fan is placed inside the cylindrical portion of the bellmouth. Normally, the first refrigerant is heavier than air, so even if the first refrigerant leaks, the first refrigerant will accumulate below the bottom end of the cylindrical portion. Here, the bottom end of the board on which the electrical equipment unit is mounted is located above the bottom end of the cylindrical portion, so the first refrigerant can be further prevented from flowing into the electrical equipment unit.
　第４観点の空調ユニットは、第１観点から第３観点のいずれかの空調ユニットであって、電装品ユニットの下端は、第１ロウ付け部よりも上方に位置する。 The air conditioning unit of the fourth aspect is an air conditioning unit of any one of the first to third aspects, in which the lower end of the electrical equipment unit is located above the first brazed portion.
　第４観点の空調ユニットでは、第１冷媒が漏洩した場合であっても、第１冷媒は第１ロウ付け部よりも下方に滞留する。ここでは、電装品ユニットが取り付けられる基板の下端が第１ロウ付け部よりも上方に位置しているので、第１冷媒が電装品ユニットに流れることをより抑制できる。 In the air conditioning unit of the fourth aspect, even if the first refrigerant leaks, the first refrigerant will remain below the first brazed portion. Here, the lower end of the board on which the electrical equipment unit is mounted is located above the first brazed portion, so that the first refrigerant can be further prevented from flowing into the electrical equipment unit.
　第５観点の空調ユニットは、第１観点から第４観点のいずれかの空調ユニットであって、第１熱交換器は、第２熱交換器よりも下方に位置する。 The fifth aspect of the air conditioning unit is an air conditioning unit according to any one of the first to fourth aspects, in which the first heat exchanger is positioned lower than the second heat exchanger.
　第５観点の空調ユニットでは、燃焼性の冷媒が流れる第１熱交換器は、非燃焼性の冷媒が流れる第２熱交換器よりも下方に配置される。このため、第１冷媒が漏洩した場合であっても、第１冷媒が下方に滞留しやすいので、第１冷媒が電装品ユニットに流れることを抑制する空調ユニットを容易に実現できる。 In the air conditioning unit of the fifth aspect, the first heat exchanger through which the flammable refrigerant flows is disposed below the second heat exchanger through which the non-flammable refrigerant flows. Therefore, even if the first refrigerant leaks, the first refrigerant tends to accumulate below, making it easy to realize an air conditioning unit that prevents the first refrigerant from flowing into the electrical equipment unit.
　第６観点の空調ユニットは、第１観点から第５観点のいずれかの空調ユニットであって、第１圧縮機と、第２圧縮機と、ベルマウスと、をさらに備える。第１圧縮機は、第２室に配置され、第１冷媒を圧縮する。第２圧縮機は、第２室に配置され、第２冷媒を圧縮する。ベルマウスは、第１室に配置され、ファンを囲む筒状部を有する。第１圧縮機のターミナル及び第２圧縮機のターミナルは、筒状部の下端よりも上方に位置する。 The air conditioning unit of a sixth aspect is the air conditioning unit of any one of the first aspect to the fifth aspect, further comprising a first compressor, a second compressor, and a bell mouth. The first compressor is disposed in the second chamber and compresses a first refrigerant. The second compressor is disposed in the second chamber and compresses a second refrigerant. The bell mouth is disposed in the first chamber and has a cylindrical portion surrounding the fan. The terminal of the first compressor and the terminal of the second compressor are located above the lower end of the cylindrical portion.
　第６観点の空調ユニットでは、第１冷媒が漏洩した場合であっても、第１冷媒はベルマウスの筒状部の下端よりも下方に滞留する。ここでは、ターミナルが筒状部の下端よりも上方に位置しているので、第２室のターミナルを着火源とした発火の可能性を減らすことができる。 In the air conditioning unit of the sixth aspect, even if the first refrigerant leaks, the first refrigerant remains below the lower end of the cylindrical portion of the bellmouth. Here, the terminal is located above the lower end of the cylindrical portion, which reduces the possibility of a fire caused by the terminal of the second chamber as an ignition source.
本開示の一実施形態に係る室外ユニットを備える二元冷凍サイクル装置の概略構成図である。1 is a schematic configuration diagram of a dual cascade refrigeration cycle device including an outdoor unit according to an embodiment of the present disclosure. 室外ユニットの断面模式図である。FIG. 2 is a schematic cross-sectional view of the outdoor unit. 室外ユニットの平面模式図である。FIG. 2 is a schematic plan view of the outdoor unit. 二元冷凍サイクル装置の冷房運転における動作を示す図である。FIG. 4 is a diagram showing the operation of the cascade refrigeration cycle device in cooling operation. 二元冷凍サイクル装置の暖房運転における動作を示す図である。FIG. 4 is a diagram showing the operation of the cascade refrigeration cycle device in heating operation. 複数のロウ付け部を示す図である。FIG. 4 is a diagram showing a plurality of brazed portions.
（１）二元冷凍サイクル装置の構成
　図１に示すように、本開示の一実施形態に係る室外ユニット２が採用された二元冷凍サイクル装置１は、蒸気圧縮式の冷凍サイクル運転を行うことによって、ビル等の室内の冷暖房に使用される装置である。 (1) Configuration of the Cascade Refrigeration Cycle Apparatus As shown in FIG. 1 , a cascade refrigeration cycle apparatus 1 employing an outdoor unit 2 according to an embodiment of the present disclosure is an apparatus used for cooling and heating the interior of a building or the like by performing a vapor compression refrigeration cycle operation.
　二元冷凍サイクル装置１は、第１サイクル１０と、第２サイクル２０と、を有する。本実施形態の二元冷凍サイクル装置１は、蒸気圧縮式の第１サイクル１０と蒸気圧縮式の第２サイクル２０とからなる二元冷媒回路を有しており、二元冷凍サイクルを行う。 The cascade refrigeration cycle device 1 has a first cycle 10 and a second cycle 20. The cascade refrigeration cycle device 1 of this embodiment has a binary refrigerant circuit consisting of a vapor compression type first cycle 10 and a vapor compression type second cycle 20, and performs a binary refrigeration cycle.
　第１サイクル１０は、燃焼性の第１冷媒が循環する。第１冷媒は、例えば、４０℃以上の臨界点を有する。第１冷媒は、例えば、炭化水素系の冷媒、Ｒ１２３４ｙｆ、Ｒ１２３４ｚｅ、Ｒ３２などであり、本実施形態ではＲ２９０である。第１冷媒の比重は、空気の比重よりも大きい。 In the first cycle 10, a combustible first refrigerant circulates. The first refrigerant has a critical point of, for example, 40°C or higher. The first refrigerant is, for example, a hydrocarbon refrigerant such as R1234yf, R1234ze, or R32, and in this embodiment, is R290. The specific gravity of the first refrigerant is greater than that of air.
　第２サイクル２０は、非燃焼性の第２冷媒が循環する。第２冷媒は、例えば、４０℃未満の臨界点を有する。第２冷媒は、例えば、二酸化炭素を含み、本実施形態では、二酸化炭素の単一冷媒である。 The second cycle 20 circulates a non-flammable second refrigerant. The second refrigerant has a critical point of, for example, less than 40°C. The second refrigerant includes, for example, carbon dioxide, and in this embodiment, the second refrigerant is a single refrigerant of carbon dioxide.
　第１サイクル１０と第２サイクル２０とは、カスケード熱交換器３０を介して、熱的に接続されている。 The first cycle 10 and the second cycle 20 are thermally connected via a cascade heat exchanger 30.
　二元冷凍サイクル装置１は、室外ユニット２と、室内ユニット３と、を備えている。二元冷凍サイクル装置１は、室外ユニット２と、室内ユニット３と、が互いに連絡配管４、５を介して接続されて構成されている。 The cascade refrigeration cycle system 1 comprises an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 and the indoor unit 3 are connected to each other via interconnecting pipes 4 and 5.
　（１－１）第１サイクル
　第１サイクル１０は、冷房運転時における過冷却回路を構成する。第１サイクル１０は、第１圧縮機１１と、第１熱交換器１２と、第１膨張機構１３と、カスケード熱交換器３０と、を含む。 (1-1) First Cycle The first cycle 10 constitutes a subcooling circuit during cooling 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.
　第１圧縮機１１は、第１冷媒を圧縮するための機器であり、例えば、圧縮機モータをインバータ制御することで運転容量を可変することが可能なスクロール型等の容積式圧縮機からなる。 The first compressor 11 is a device for compressing the first refrigerant, and is, for example, a volumetric compressor such as a scroll type whose operating capacity can be varied by inverter controlling the compressor motor.
　図２に示すように、第１圧縮機１１は、第１ターミナル１１１を有している。第１ターミナル１１１には、給電用の配線が接続される。ここでは、第１ターミナル１１１は、ハーネス結線部である。 As shown in FIG. 2, the first compressor 11 has a first terminal 111. A power supply wiring is connected to the first terminal 111. Here, the first terminal 111 is a harness connection portion.
　第１熱交換器１２は、第１冷媒と室外空気との熱交換を行うための機器である。第１熱交換器１２において、第１冷媒は、室外空気から冷熱または温熱を取得する。第１熱交換器１２は、例えば、多数の伝熱管及びフィンによって構成されたフィン・アンド・チューブ型熱交換器からなる。 The first heat exchanger 12 is a device for exchanging heat between the first refrigerant and the outdoor air. In the first heat exchanger 12, the first refrigerant obtains cold or hot heat from the outdoor air. The first heat exchanger 12 is, for example, a fin-and-tube type heat exchanger made up of a large number of heat transfer tubes and fins.
　第１膨張機構１３は、第１冷媒を減圧する機器であり、例えば、電動膨張弁である。 The first expansion mechanism 13 is a device that reduces the pressure of the first refrigerant, and is, for example, an electric expansion valve.
　カスケード熱交換器３０は、第１冷媒と、第２冷媒との間で、互いに混合させることなく熱交換を行わせるための機器である。カスケード熱交換器３０は、例えば、プレート型熱交換器からなる。カスケード熱交換器３０は、第１サイクル１０に属する第１流路３１と、第２サイクル２０に属する第２流路３２と、を有している。第１流路３１は、そのガス側が、第１圧縮機１１に接続され、その液側が、第１膨張機構１３に接続されている。 The cascade heat exchanger 30 is a device for performing heat exchange between a first refrigerant and a second refrigerant without mixing them. The cascade heat exchanger 30 is, 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 is connected to the first expansion mechanism 13.
　第１熱交換器１２を凝縮器として用いるとともに、後述する第２サイクル２０の第２熱交換器２３を放熱器として用いたときに、カスケード熱交換器３０は、第２熱交換器２３で冷却された第２冷媒を過冷却することを目的としており、第２サイクル２０のアシストの役割を担う。 When the first heat exchanger 12 is used as a condenser and the second heat exchanger 23 of the second cycle 20 described below is used as a radiator, the cascade heat exchanger 30 is intended to supercool the second refrigerant cooled by the second heat exchanger 23, and serves as an assistant to the second cycle 20.
　（１－２）第２サイクル
　第２サイクル２０は、第２圧縮機２１と、切換機構２２と、第２熱交換器２３と、カスケード熱交換器３０と、第２膨張機構２４と、第３熱交換器２５と、を含む。 (1-2) Second Cycle 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.
　第２圧縮機２１は、第２冷媒を圧縮するための機器であり、例えば、圧縮機モータをインバータ制御することで運転容量を可変することが可能なスクロール型等の容積式圧縮機からなる。 The second compressor 21 is a device for compressing the second refrigerant, and is, for example, a scroll type or other positive displacement compressor whose operating capacity can be varied by inverter controlling the compressor motor.
　図２に示すように、第２圧縮機２１は、第２ターミナル２１１を有している。第２ターミナル２１１には、給電用の配線が接続される。ここでは、第２ターミナル２１１は、ハーネス結線部である。 As shown in FIG. 2, the second compressor 21 has a second terminal 211. A power supply wiring is connected to the second terminal 211. Here, the second terminal 211 is a harness connection portion.
　切換機構２２は、第２熱交換器２３を第２冷媒の放熱器として機能させ、かつ、第３熱交換器２５を第２冷媒の蒸発器として機能させる第１状態（図１の切換機構２２の実線を参照）と、第２熱交換器２３を第２冷媒の蒸発器として機能させ、かつ、第３熱交換器２５を第２冷媒の放熱器として機能させる第２状態（図１の切換機構２２の破線を参照）と、を切り換える機器である。切換機構２２は、例えば、四路切換弁である。そして、切換機構２２は、第１状態において、第２圧縮機２１の吐出側と第２熱交換器２３のガス側とを接続し、かつ、第２圧縮機２１の吸入側と第３熱交換器２５のガス側とを接続する。また、切換機構２２は、第２状態において、第２圧縮機２１の吐出側と第３熱交換器２５のガス側とを接続し、かつ、第２圧縮機２１の吸入側と第２熱交換器２３のガス側とを接続する。 The switching mechanism 22 is a device that switches between a first state (see the solid line of the switching mechanism 22 in Figure 1) 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, and a second state (see the dashed line of the switching mechanism 22 in Figure 1) 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. The switching mechanism 22 is, for example, a four-way switching valve. In the first state, 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 addition, in the second state, the switching mechanism 22 connects the discharge side of the second compressor 21 to the gas side of the third heat exchanger 25, and also connects the suction side of the second compressor 21 to the gas side of the second heat exchanger 23.
　第２熱交換器２３は、第２冷媒と室外空気との熱交換を行うための機器である。第２熱交換器２３において、第２冷媒は、室外空気から冷熱または温熱を取得する。第２熱交換器２３は、例えば、多数の伝熱管及びフィンによって構成されたフィン・アンド・チューブ型熱交換器からなる。 The second heat exchanger 23 is a device for exchanging heat between the second refrigerant and the outdoor air. In the second heat exchanger 23, the second refrigerant obtains cold or hot heat from the outdoor air. The second heat exchanger 23 is, for example, a fin-and-tube type heat exchanger made up of a large number of heat transfer tubes and fins.
　第２サイクル２０は、カスケード熱交換器３０の第２流路３２を有する。第２流路３２は、第２状態において、そのガス側が、第２熱交換器２３に接続され、その液側が、第３熱交換器２５に接続されている。 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 is connected to the third heat exchanger 25.
　第２膨張機構２４は、第２冷媒を減圧する機器であり、例えば、電動膨張弁である。 The second expansion mechanism 24 is a device that reduces the pressure of the second refrigerant, and is, for example, an electric expansion valve.
　第３熱交換器２５は、第２冷媒と室内空気との熱交換を行うための機器であり、例えば、多数の伝熱管及びフィンによって構成されたフィン・アンド・チューブ型熱交換器からなる。 The third heat exchanger 25 is a device for exchanging heat between the second refrigerant and the indoor air, and is, for example, a fin-and-tube type heat exchanger made up of a large number of heat transfer tubes and fins.
　（１－３）室外ユニット
　以下の説明において、「上」、「下」、「前」等の方向を示す表現を適宜用いているが、これらは、室外ユニット２が室外に取り付けられ、通常使用される状態での各方向を表す。本実施形態では、上下方向は、鉛直方向である。 (1-3) Outdoor Unit In the following description, expressions indicating directions such as "up,""down," and "front" are used as appropriate, but these indicate the directions when the outdoor unit 2 is installed outdoors and in normal use. In this embodiment, the up-down direction is the vertical direction.
　室外ユニット２は、室内ユニット３が配置された空間とは異なる空間に配置される。ここでは、室外ユニット２は、室外（建物の屋上や建物の外壁面近傍等）に設置されている。 The outdoor unit 2 is placed in a space different from the space in which the indoor unit 3 is placed. Here, the outdoor unit 2 is installed outdoors (on the roof of a building, near the exterior wall of a building, etc.).
　室外ユニット２は、上述の第１サイクル１０と、第２サイクル２０の一部と、ケーシング４１と、電装品４２と基板４３とを含む電装品ユニット４２０と、ファン４４と、ベルマウス４５と、仕切板４６と、冷媒漏洩センサ４７と、を有している。具体的には、室外ユニット２は、図１に示す第１圧縮機１１と、第１熱交換器１２と、第１膨張機構１３と、第２圧縮機２１と、切換機構２２と、第２熱交換器２３と、第２膨張機構２４と、カスケード熱交換器３０と、図２に示すケーシング４１と、電装品４２と、基板４３と、ファン４４と、ベルマウス４５と、仕切板４６と、冷媒漏洩センサ４７と、を有している。 The outdoor unit 2 has the above-mentioned first cycle 10, a part of the second cycle 20, a casing 41, an electrical equipment unit 420 including electrical equipment 42 and a board 43, a fan 44, a bell mouth 45, a partition plate 46, and a refrigerant leakage sensor 47. Specifically, the outdoor unit 2 has the first compressor 11, first heat exchanger 12, first expansion mechanism 13, second compressor 21, switching mechanism 22, second heat exchanger 23, second expansion mechanism 24, cascade heat exchanger 30 shown in FIG. 1, and the casing 41, electrical equipment 42, board 43, fan 44, bell mouth 45, partition plate 46, and refrigerant leakage sensor 47 shown in FIG. 2.
　ケーシング４１は、第１圧縮機１１と、第１熱交換器１２と、第１膨張機構１３と、第２圧縮機２１と、切換機構２２と、第２熱交換器２３と、第２膨張機構２４と、カスケード熱交換器３０と、電装品４２と、基板４３と、ファン４４と、ベルマウス４５と、仕切板４６と、冷媒漏洩センサ４７と、を収容する。 The casing 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 electrical components 42, the circuit board 43, the fan 44, the bell mouth 45, the partition plate 46, and the refrigerant leakage sensor 47.
　図２に示すケーシング４１は、略直方体の形状を有している。具体的には、ケーシング４１は、前板４１１と、天板４１２と、底板４１３と、側板４１４とを含む。 The casing 41 shown in FIG. 2 has a generally rectangular parallelepiped shape. Specifically, the casing 41 includes a front plate 411, a top plate 412, a bottom plate 413, and side plates 414.
　前板４１１は、ケーシング４１の前側の面を構成する板状部材である。前板４１１には、吹出口が形成されている。吹出口は、ケーシング４１の外部から内部に取り込まれた室外空気を、ケーシング４１の外部に吹き出すための開口である。 The front plate 411 is a plate-like member that forms the front surface of the casing 41. An air outlet is formed in the front plate 411. The air outlet is an opening for blowing the outdoor air that has been taken in from the outside of the casing 41 to the inside of the casing 41 out to the outside of the casing 41.
　天板４１２は、ケーシング４１の上側の面を構成する板状部材である。底板４１３は、ケーシング４１の下側の面を構成する板状部材である。天板４１２と底板４１３とは、対向する。 The top plate 412 is a plate-like member that forms the upper surface of the casing 41. The bottom plate 413 is a plate-like member that forms the lower surface of the casing 41. The top plate 412 and the bottom plate 413 face each other.
　側板４１４は、ケーシング４１の側面を構成する板状部材である。側板４１４の下部は、底板４１３に固定される。 The side plate 414 is a plate-like member that forms the side surface of the casing 41. The lower portion of the side plate 414 is fixed to the bottom plate 413.
　ケーシング４１には、後述する仕切板４６の連通孔４６１に室外空気を流すための開口部４１５が形成されている。ここでは、開口部４１５は、後述する第２室Ｓ２を区画する側板４１４に形成されている。なお、開口部４１５は、必ずしも、側板４１４に形成される必要はなく、第２室Ｓ２とケーシング４１外部とを区画するいずれかの部材に設けることができる。 The casing 41 has an opening 415 for allowing outside air to flow to the communication hole 461 of the partition plate 46 described below. Here, the opening 415 is formed in the side plate 414 that partitions the second chamber S2 described below. Note that the opening 415 does not necessarily have to be formed in the side plate 414, and can be provided in any member that partitions the second chamber S2 from the outside of the casing 41.
　電装品ユニット４２０は、基板４３に電装品４２（電気部品）が装着されたものである。 The electrical equipment unit 420 has electrical equipment 42 (electrical components) mounted on a board 43.
　電装品４２は、第１圧縮機１１、第２圧縮機２１、第１膨張機構１３、切換機構２２、第２膨張機構２４等の制御対象を制御する。電装品４２は、例えば、パワー素子等の被冷却素子、リアクトル、コンデンサ、配線接続部等を含む。 The electrical equipment 42 controls the controlled objects such as the first compressor 11, the second compressor 21, the first expansion mechanism 13, the switching mechanism 22, and the second expansion mechanism 24. The electrical equipment 42 includes, for example, cooled elements such as power elements, reactors, capacitors, wiring connections, etc.
　基板４３には、電装品４２が取り付けられる。基板４３は、例えば、プリント基板である。基板４３は、上下方向に延びる。ここでは、基板４３に、複数の電装品４２が取り付けられる。 Electrical components 42 are attached to the board 43. The board 43 is, for example, a printed circuit board. The board 43 extends in the vertical direction. Here, multiple electrical components 42 are attached to the board 43.
　ファン４４は、第１熱交換器１２及び第２熱交換器２３に空気を流す。本実施形態では、ファン４４は、第１熱交換器１２及び第２熱交換器２３の両方に、室外空気を流す。ここでは、ファン４４は、室外空気を第１熱交換器１２及び第２熱交換器２３に導いて、第１熱交換器１２を流れる第１冷媒と熱交換させた後、及び、第２熱交換器２３を流れる第２冷媒と熱交換させた後に、室外に排出させる、という空気流れを生じさせる。ファン４４は、ファンモータによって駆動される。なお、第１熱交換器１２に空気を流すファンと、第２熱交換器２３に空気を流すファンとが、別々に設けられてもよい。 The fan 44 directs air to the first heat exchanger 12 and the second heat exchanger 23. In this embodiment, the fan 44 directs outdoor air to both the first heat exchanger 12 and the second heat exchanger 23. Here, the fan 44 guides the outdoor air to the first heat exchanger 12 and the second heat exchanger 23, where the outdoor air is heat exchanged with the first refrigerant flowing through the first heat exchanger 12 and with the second refrigerant flowing through the second heat exchanger 23, and then discharged to the outside. The fan 44 is driven by a fan motor. Note that the fan that directs air to the first heat exchanger 12 and the fan that directs air to the second heat exchanger 23 may be provided separately.
　ベルマウス４５は、ファン４４の吹出側に配置される。ベルマウス４５は、ファン４４を囲む筒状部を有する。筒状部は、開口を形成する。筒状部の内側に、ファン４４が配置されている。 The bellmouth 45 is disposed on the blowing side of the fan 44. The bellmouth 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.
　図２では、前面から見たときに、ファン４４及びベルマウス４５は、第１熱交換器１２及び第２熱交換器２３に重なっている。ベルマウス４５は、ケーシング４１の前板４１１に形成された吹出口（図示せず）と対向する。 In FIG. 2, when viewed from the front, the fan 44 and the bellmouth 45 overlap the first heat exchanger 12 and the second heat exchanger 23. The bellmouth 45 faces an air outlet (not shown) formed in the front plate 411 of the casing 41.
　冷媒漏洩センサ４７は、第１冷媒の漏洩を検出する。冷媒漏洩センサ４７は、ケーシング４１内の下方に設置される。なお、冷媒漏洩センサ４７は、第２冷媒の漏洩をさらに検出してもよい。 The refrigerant leakage sensor 47 detects leakage of the first refrigerant. The refrigerant leakage sensor 47 is installed at the bottom inside the casing 41. The refrigerant leakage sensor 47 may also detect leakage of the second refrigerant.
　仕切板４６は、上下方向に延びる板状部材である。仕切板４６の下部は、ケーシング４１の底板４１３に固定される。 The partition plate 46 is a plate-shaped member that extends in the vertical direction. The lower part of the partition plate 46 is fixed to the bottom plate 413 of the casing 41.
　仕切板４６は、ケーシング４１内を、第１室Ｓ１と第２室Ｓ２と、に仕切る。第１室Ｓ１及び第２室Ｓ２のそれぞれは、ケーシング４１の前板４１１、天板４１２、底板４１３及び側板４１４と仕切板４６とで区画される空間である。 The partition plate 46 divides the inside of the casing 41 into a first chamber S1 and a second chamber S2. The first chamber S1 and the second chamber S2 are each a space defined by the front plate 411, the top plate 412, the bottom plate 413, and the side plates 414 of the casing 41 and the partition plate 46.
　ここでは、第１室Ｓ１は、送風室であり、室外ユニット２の吸込口から吸い込んだ空気が吹出口に流れる導風路である。第２室Ｓ２は、機械室である。 Here, the first chamber S1 is an air blowing chamber, and is an air guide passage through which air drawn in from the air intake of the outdoor unit 2 flows to the air outlet. The second chamber S2 is a machine room.
　本実施形態では、第１室Ｓ１には、第１熱交換器１２、第２熱交換器２３、ファン４４、及びベルマウス４５が配置される。第２室Ｓ２には、第１圧縮機１１、第２圧縮機２１、切換機構２２、第１膨張機構１３、第２膨張機構２４、電装品４２と基板４３とを含む電装品ユニット４２０、及び冷媒漏洩センサ４７が配置される。 In this embodiment, the first heat exchanger 12, the second heat exchanger 23, the fan 44, and the bell mouth 45 are arranged in the first chamber S1. The second chamber S2 is arranged with the first compressor 11, the second compressor 21, the switching mechanism 22, the first expansion mechanism 13, the second expansion mechanism 24, the electrical equipment unit 420 including the electrical equipment 42 and the board 43, and the refrigerant leakage sensor 47.
　仕切板４６には、連通孔４６１が設けられている。連通孔４６１は、図５に示すように、第１熱交換器１２の複数のロウ付け部１２０のうち最も上方に位置する第１ロウ付け部１２１よりも上方に設けられている。 The partition plate 46 has a communication hole 461. As shown in FIG. 5, the communication hole 461 is provided above the first brazed portion 121, which is the uppermost of the multiple brazed portions 120 of the first heat exchanger 12.
　なお、ロウ付け部１２０は、第１室Ｓ１において、第１熱交換器１２から第１冷媒が漏洩する可能性のある部分である。本実施形態のロウ付け部１２０は、第１熱交換器１２を構成する伝熱管同士の接合部分、伝熱管とフィンとの接合部分などである。伝熱管は、Ｕ字管、分岐管などを含む。ここでは、複数のロウ付け部１２０は、ヘアピン状の管と、Ｕ字管や分岐管との接合部分である。なお、マイクロチャネル式の熱交換器等のように、伝熱管とフィンとがロウ付けされる場合は、そのロウ付けされている箇所もロウ付け部となる。 The brazed portions 120 are portions in the first chamber S1 where the first refrigerant may leak from the first heat exchanger 12. In this embodiment, the brazed portions 120 are joints between the heat transfer tubes that make up the first heat exchanger 12, joints between the heat transfer tubes and the fins, etc. Heat transfer tubes include U-shaped tubes and branch tubes. Here, the multiple brazed portions 120 are joints between hairpin-shaped tubes and U-shaped tubes or branch tubes. In addition, when the heat transfer tubes and fins are brazed, such as in a microchannel heat exchanger, the brazed portions also become brazed portions.
　図２Ａにおいて、連通孔４６１の上下方向の高さ位置をＰ１で示し、第１ロウ付け部１２１の上下方向の高さ位置をＰ２で示す。連通孔４６１の上下方向の高さ位置Ｐ１は、連通孔４６１の最下端である。このため、連通孔４６１の最下端の高さ位置Ｐ１は、第１ロウ付け部１２１の上下方向の高さ位置よりも上である。 In FIG. 2A, the vertical height position of the communication hole 461 is indicated by P1, and the vertical height position of the first brazed portion 121 is indicated by P2. The vertical height position P1 of the communication hole 461 is the lowest end of the communication hole 461. Therefore, the height position P1 of the lowest end of the communication hole 461 is higher than the vertical height position of the first brazed portion 121.
　連通孔４６１は、ケーシング４１の開口部４１５から第２室Ｓ２に流入する室外空気を、第１室Ｓ１に導くための孔である。本実施形態の連通孔４６１は、電装品４２及び基板４３を含む電装品ユニット４２０周りの空気をファン４４へ導くための孔である。換言すると、連通孔４６１は、第２室Ｓ２の電装品４２及び基板４３を含む電装品ユニット４２０周りの室外空気を、第１室Ｓ１のファン４４に導くための孔である。 The communication hole 461 is a hole for guiding the outside air that flows into the second chamber S2 from the opening 415 of the casing 41 to the first chamber S1. In this embodiment, the communication hole 461 is a hole for guiding the air around the electrical component unit 420, which includes the electrical components 42 and the board 43, to the fan 44. In other words, the communication hole 461 is a hole for guiding the outside air around the electrical component unit 420, which includes the electrical components 42 and the board 43 in the second chamber S2, to the fan 44 in the first chamber S1.
　図２では、連通孔４６１は、第１熱交換器１２の上端よりも上方に位置する。また、連通孔４６１の高さ位置Ｐ１は、第２熱交換器２３と重なる。 In FIG. 2, the communication hole 461 is located above the upper end of the first heat exchanger 12. Also, the height position P1 of the communication hole 461 overlaps with the second heat exchanger 23.
　また、連通孔４６１は、ベルマウス４５の筒状部の下端４５１よりも上方に位置する。また、連通孔４６１は、第１圧縮機１１の第１ターミナル１１１及び第２圧縮機２１の第２ターミナル２１１よりも上方に位置する。 The communication hole 461 is located above the lower end 451 of the cylindrical portion of the bell mouth 45. 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.
　さらに、連通孔４６１は、電装品ユニット４２０（ここでは基板４３）の下端４３１よりも上方に位置する。ここでは、連通孔４６１の最下端の高さ位置Ｐ１は、複数の電装品４２のうち最も下方に位置する電装品４２よりも上方に位置する。 Furthermore, the communication hole 461 is located above the lower end 431 of the electrical equipment unit 420 (here, the board 43). Here, the height position P1 of the lowest end of the communication hole 461 is located above the electrical equipment 42 that is located at the lowest among the multiple electrical equipment 42.
　ここで、室外ユニット２のケーシング４１の内部に収容された各種機器の配置について説明する。 Here, we will explain the layout of the various devices housed inside the casing 41 of the outdoor unit 2.
　第１室Ｓ１において、第１熱交換器１２は、第２熱交換器２３よりも下方に位置する。換言すると、第１熱交換器１２の少なくとも一部は、第２熱交換器２３よりも下方に位置する。第１熱交換器１２の全体が、第２熱交換器２３よりも下方に位置してもよく、第１熱交換器１２の一部が、第２熱交換器２３よりも下方に位置してもよい。 In the first chamber S1, the first heat exchanger 12 is located below the second heat exchanger 23. In other words, at least a portion of the first heat exchanger 12 is located below the second heat exchanger 23. The entire first heat exchanger 12 may be located below the second heat exchanger 23, or a portion of the first heat exchanger 12 may be located below the second heat exchanger 23.
　なお、第１熱交換器１２と第２熱交換器２３とは、別体であってもよく、一体であってもよい。また、第１熱交換器１２のサイズは、第２熱交換器２３のサイズと同程度であってもよく、上下方向の高さ方向において小さくてもよい。 The first heat exchanger 12 and the second heat exchanger 23 may be separate or integrated. The size of the first heat exchanger 12 may be approximately the same as the size of the second heat exchanger 23, and may be smaller in the vertical height direction.
　また、第２室Ｓ２において、電装品４２及び基板４３を含む電装品ユニット４２０は、第１圧縮機１１及び第２圧縮機２１の上方に配置されている。 In addition, in the second chamber S2, the electrical equipment unit 420 including the electrical equipment 42 and the circuit board 43 is disposed above the first compressor 11 and the second compressor 21.
　また、ケーシング４１内において、電装品ユニット４２０（ここでは基板４３）の下端４３１は、ベルマウス４５の筒状部の下端４５１よりも上方に位置する。換言すると、電装品ユニット４２０（ここでは電装品４２が付く基板４３）の下端４３１の上下方向の高さ位置は、ファン４４の吹出側に配置されるベルマウス４５の開口下端４５１よりも高い。 In addition, within the casing 41, the lower end 431 of the electrical equipment unit 420 (here, the board 43) is located above the lower end 451 of the cylindrical portion of the bellmouth 45. In other words, the vertical height position of the lower end 431 of the electrical equipment unit 420 (here, the board 43 to which the electrical equipment 42 is attached) is higher than the opening lower end 451 of the bellmouth 45, which is located on the blowing side of the fan 44.
　ここでは、複数の電装品４２のうち最も下方に位置する電装品４２は、ベルマウス４５の筒状部の下端４５１よりも上方に位置する。 Here, the lowest electrical component 42 among the multiple electrical components 42 is located above the lower end 451 of the cylindrical portion of the bellmouth 45.
　また、電装品ユニット４２０（ここでは基板４３）の下端４３１は、第１ロウ付け部１２１よりも上方に位置する。換言すると、電装品ユニット４２０（ここでは電装品４２が付く基板４３）の高さ位置は、第１ロウ付け部１２１の高さ位置Ｐ１よりも上方である。 In addition, the lower end 431 of the electrical component unit 420 (here, the board 43) is located above the first brazing portion 121. In other words, the height position of the electrical component unit 420 (here, the board 43 to which the electrical components 42 are attached) is above the height position P1 of the first brazing portion 121.
　ここでは、複数の電装品４２のうち最も下方に位置する電装品４２は、第１ロウ付け部１２１よりも上方に位置する。 Here, the electrical component 42 located at the lowest position among the multiple electrical components 42 is located above the first brazing portion 121.
　また、第１圧縮機１１の第１ターミナル１１１及び第２圧縮機２１の第２ターミナル２１１は、ベルマウス４５の筒状部の下端４５１よりも上方に位置する。ここでは、第１圧縮機１１の第１ターミナル１１１の下端及び第２圧縮機２１の第２ターミナル２１１の下端は、ベルマウス４５の筒状部の下端４５１よりも上方に位置する。 Furthermore, 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 end of the first terminal 111 of the first compressor 11 and the lower end of 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.
　（１－４）室内ユニット
　室内ユニット３は、室内（建物内）に設置されている。室内ユニット３は、上記のように、連絡配管４、５を介して室外ユニット２に接続されており、第２サイクル２０の一部を構成している。 (1-4) Indoor Unit The indoor unit 3 is installed indoors (inside the building). As described above, the indoor unit 3 is connected to the outdoor unit 2 via the connecting pipes 4 and 5, and constitutes a part of the second cycle 20.
　図１に示すように、室内ユニット３は、第３熱交換器２５を有している。ここでは、室内ユニット３は、ビル等の室内の天井に埋め込みや吊り下げ等、または、室内の壁面に壁掛け等により設置されている。 As shown in FIG. 1, the indoor unit 3 has a third heat exchanger 25. Here, the indoor unit 3 is installed by embedding or hanging in the ceiling of a room of a building or the like, or by hanging on a wall surface of the room.
　（１－５）連絡配管
　連絡配管４、５は、二元冷凍サイクル装置１を建物等の設置場所に設置する際に、現地にて施工される冷媒管である。液側の連絡配管４の一端は、室外ユニット２の液側の端部に接続され、連絡配管４の他端は、室内ユニット３の第３熱交換器２５の液側の端部に接続されている。ガス側の連絡配管５の一端は、室外ユニット２のガス側の端部に接続され、連絡配管５の他端は、室内ユニット３の第３熱交換器２５のガス側の端部に接続されている。 (1-5) Communication Pipes The communication pipes 4, 5 are refrigerant pipes that are installed on-site when the cascade refrigeration cycle apparatus 1 is installed in an installation location such as a building. One end of the liquid side communication pipe 4 is connected to the liquid side end of the outdoor unit 2, and the other end of the communication 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 communication pipe 5 is connected to the gas side end of the outdoor unit 2, and the other end of the communication pipe 5 is connected to the gas side end of the third heat exchanger 25 of the indoor unit 3.
　（１－６）制御部
　上記の室外ユニット２及び室内ユニット３の構成機器は、制御部６によって制御されるようになっている。制御部６は、室外ユニット２に設けられた電装品４２、基板４３等や室内ユニット３に設けられた制御基板等（図示せず）が通信接続されることによって構成されている。なお、図１においては、便宜上、室外ユニット２や室内ユニット３等とは離れた位置に制御部６を図示している。制御部６は、二元冷凍サイクル装置１（ここでは、室外ユニット２及び室内ユニット３）の構成機器の制御を行う。換言すると、制御部６は、二元冷凍サイクル装置１全体の運転制御を行うようになっている。 (1-6) Control Unit The components of the outdoor unit 2 and the indoor unit 3 are controlled by the control unit 6. The control unit 6 is configured by communication connection between the electrical equipment 42, the board 43, etc. provided in the outdoor unit 2 and the control board, etc. (not shown) provided in the indoor unit 3. For convenience, the control unit 6 is illustrated in FIG. 1 at a position separate from the outdoor unit 2 and the indoor unit 3. The control unit 6 controls the components of the cascade refrigeration cycle apparatus 1 (here, the outdoor unit 2 and the indoor unit 3). In other words, the control unit 6 controls the operation of the entire cascade refrigeration cycle apparatus 1.
　制御部６はコンピュータにより実現されるものである。制御部６は、制御演算装置と記憶装置とを備える。制御演算装置には、ＣＰＵ又はＧＰＵといったプロセッサを使用できる。制御演算装置は、記憶装置に記憶されているプログラムを読み出し、このプログラムに従って所定の画像処理や演算処理を行う。さらに、制御演算装置は、プログラムに従って、演算結果を記憶装置に書き込んだり、記憶装置に記憶されている情報を読み出したりすることができる。 The control unit 6 is realized by a computer. The control unit 6 includes a control arithmetic unit and a storage device. The control arithmetic unit can be a processor such as a CPU or a GPU. The control arithmetic unit reads a program stored in the storage device, and performs predetermined image processing and arithmetic processing according to the program. Furthermore, the control arithmetic unit can write the results of calculations to the storage device and read information stored in the storage device according to the program.
　（２）二元冷凍サイクル装置の動作
　二元冷凍サイクル装置１の動作について、図１～図４を用いて説明する。二元冷凍サイクル装置１は、室内の空気調和のために、室内空気を冷却する冷房運転及び室内空気を加熱する暖房運転を行うことが可能である。冷房運転及び暖房運転において、二元冷凍サイクル装置１の動作は、制御部６によって制御される。 (2) Operation of the cascade refrigeration cycle device The operation of the cascade refrigeration cycle device 1 will be described with reference to Figures 1 to 4. The cascade refrigeration cycle device 1 is capable of performing a cooling operation for cooling indoor air and a heating operation for heating indoor air for air conditioning. In the cooling operation and the heating operation, the operation of the cascade refrigeration cycle device 1 is controlled by the control unit 6.
　（２－１）冷房運転
　図３に示すように、冷房運転の際、第２熱交換器２３が第２冷媒の放熱器として機能し、かつ第３熱交換器２５が第２冷媒の蒸発器として機能するように、切換機構２２が第１状態（切換機構２２が実線の状態）に切り換えられる。 (2-1) Cooling Operation As shown in FIG. 3, during cooling operation, the switching mechanism 22 is switched to the first state (the state in which the switching mechanism 22 is in the 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.
　第２サイクル２０では、第２圧縮機２１から吐出された第２冷媒は、切換機構２２を通じて第２熱交換器２３に送られる。第２熱交換器２３に送られた第２冷媒は、ファン４４によって供給される室外空気と熱交換を行って冷却されることによって放熱する。第２熱交換器２３において放熱した第２冷媒は、カスケード熱交換器３０の第２流路３２に送られる。第２流路３２に送られた第２冷媒は、カスケード熱交換器３０において、第１流路３１を流れる第１冷媒と熱交換を行ってさらに冷却される。カスケード熱交換器３０でさらに冷却された第２冷媒は、第２膨張機構２４によって減圧された後に、室外ユニット２から流出する。 In the second cycle 20, the second refrigerant discharged from the second compressor 21 is sent to the second heat exchanger 23 through the switching mechanism 22. The second refrigerant sent to the second heat exchanger 23 is cooled by exchanging heat with the outdoor air supplied by the fan 44, thereby releasing heat. The second refrigerant that has released heat in the second heat exchanger 23 is sent to the second flow path 32 of the cascade heat exchanger 30. The second refrigerant sent to the second flow path 32 is further cooled in the cascade heat exchanger 30 by exchanging heat with the first refrigerant flowing through the first flow path 31. The second refrigerant that has been further cooled in the cascade heat exchanger 30 is depressurized by the second expansion mechanism 24 and then flows out of the outdoor unit 2.
　室外ユニット２から流出した第２冷媒は、液側の連絡配管４を経由して、室内ユニット３に流入する。室内ユニット３では、第２冷媒は、第３熱交換器２５に送られる。第３熱交換器２５に送られた第２冷媒は、室内空気と熱交換を行って加熱されることによって蒸発する。第３熱交換器２５において蒸発した第２冷媒は、室内ユニット３から流出する。 The second refrigerant that flows out of the outdoor unit 2 flows into the indoor unit 3 via the liquid side connecting pipe 4. In the indoor unit 3, the second refrigerant is sent to the third heat exchanger 25. The second refrigerant sent to the third heat exchanger 25 evaporates by being heated through heat exchange with the indoor air. The second refrigerant that has evaporated in the third heat exchanger 25 flows out of the indoor unit 3.
　室内ユニット３から流出した第２冷媒は、ガス側の連絡配管５を経由して、室外ユニット２に流入する。室外ユニット２では、第２冷媒は、切換機構２２を通じて、再び第２圧縮機２１に吸入される。 The second refrigerant that flows out of the indoor unit 3 flows into the outdoor unit 2 via the gas side connecting pipe 5. In the outdoor unit 2, the second refrigerant is sucked back into the second compressor 21 via the switching mechanism 22.
　第１サイクル１０では、第１圧縮機１１から吐出された第１冷媒は、第１熱交換器１２に送られる。第１熱交換器１２に送られた第１冷媒は、ファン４４によって供給される室外空気と熱交換を行って冷却されることによって凝縮する。第１熱交換器１２において凝縮した第１冷媒は、第１膨張機構１３によって減圧された後に、カスケード熱交換器３０の第１流路３１に送られる。第１流路３１に送られた第１冷媒は、カスケード熱交換器３０において、第２流路３２を流れる第２冷媒と熱交換を行って加熱されることによって蒸発する。カスケード熱交換器３０で蒸発した第１冷媒は、再び第１圧縮機１１に吸入される。 In the first cycle 10, the first refrigerant discharged from the first compressor 11 is sent to the first heat exchanger 12. The first refrigerant sent to the first heat exchanger 12 is cooled and condensed by heat exchange with the outdoor air supplied by the fan 44. The first refrigerant condensed in the first heat exchanger 12 is depressurized by the first expansion mechanism 13 and then sent to the first flow path 31 of the cascade heat exchanger 30. The first refrigerant sent to the first flow path 31 is heated in the cascade heat exchanger 30 by heat exchange with the second refrigerant flowing in the second flow path 32, and evaporates. The first refrigerant evaporated in the cascade heat exchanger 30 is sucked back into the first compressor 11.
　（２－２）暖房運転
　図４に示すように、暖房運転の際、第２熱交換器２３が第２冷媒の蒸発器として機能し、かつ第３熱交換器２５が第２冷媒の放熱器として機能するように、切換機構２２が第２状態（切換機構２２が破線の状態）に切り換えられる。また、暖房運転では、第１圧縮機１１を起動せずに、第１サイクル１０の第１冷媒を循環させない。 4, during heating operation, the switching mechanism 22 is switched to the second state (the state in which the switching mechanism 22 is in the broken line) so that the second heat exchanger 23 functions as an evaporator of the second refrigerant and the third heat exchanger 25 functions as a radiator of the second refrigerant. Also, during heating operation, the first compressor 11 is not started, and the first refrigerant is not circulated in the first cycle 10.
　第２サイクル２０では、第２圧縮機２１から吐出された第２冷媒は、切換機構２２を通じて室外ユニット２から流出する。 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.
　室外ユニット２から流出した冷媒は、ガス側の連絡配管５を経由して、室内ユニット３に流入する。室内ユニット３では、第２冷媒は、第３熱交換器２５に送られる。第３熱交換器２５に送られた第２冷媒は、室内空気と熱交換を行って冷却されることによって放熱する。第３熱交換器２５において放熱した第２冷媒は、室内ユニット３から流出する。 The refrigerant flowing out of the outdoor unit 2 flows into the indoor unit 3 via the gas side connecting pipe 5. In the indoor unit 3, the second refrigerant is sent to the third heat exchanger 25. The second refrigerant sent to the third heat exchanger 25 exchanges heat with the indoor air and is cooled, thereby releasing heat. The second refrigerant that has released heat in the third heat exchanger 25 flows out of the indoor unit 3.
　室内ユニット３から流出した第２冷媒は、液側の連絡配管４を経由して、室外ユニット２に流入する。室外ユニット２では、第２冷媒は、第２膨張機構２４及びカスケード熱交換器３０の第２流路３２を通じて、第２熱交換器２３に送られる。第２熱交換器２３に送られた第２冷媒は、ファン４４によって供給される室外空気と熱交換を行って加熱されることによって蒸発する。第２熱交換器２３において蒸発した第２冷媒は、切換機構２２を通じて、再び第２圧縮機２１に吸入される。 The second refrigerant flowing out of the indoor unit 3 flows into the outdoor unit 2 via the liquid side connecting pipe 4. In the outdoor unit 2, the second refrigerant is sent 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 sent to the second heat exchanger 23 evaporates by being heated through heat exchange with the outdoor air supplied by the fan 44. The second refrigerant evaporated in the second heat exchanger 23 is sucked back into the second compressor 21 through the switching mechanism 22.
　（３）冷媒漏洩時の第１冷媒の流れ
　図２Ａの矢印Ａに示すように、室外ユニット２において、室外空気は、ケーシング４１の側板４１４の開口部４１５から第２室Ｓ２に流れ、さらに、仕切板４６の連通孔４６１を通過して、第１室Ｓ１に流れる。ここでは、連通孔４６１を通過した室外空気は、ファン４４に流れる。ファン４４の駆動中には、室外空気は、第１室Ｓ１からケーシング４１の外部に流れる。 (3) Flow of the first refrigerant during refrigerant leakage As shown by arrow A in Fig. 2A, in the outdoor unit 2, outside air flows from the opening 415 in the side plate 414 of the casing 41 to the second chamber S2, and further passes through the communication hole 461 in the partition plate 46 to flow into the first chamber S1. Here, the outside air that has passed through the communication hole 461 flows to the fan 44. When the fan 44 is driving, the outside air flows from the first chamber S1 to the outside of the casing 41.
　第２冷媒は非燃焼性なので、漏洩したときの危険性は低いが、第１冷媒は燃焼性なので、着火源となる電装品ユニット４２０（特に電装品４２）に第１冷媒が流れると発火する恐れがある。第１冷媒が漏洩する可能性が高い箇所は、第１熱交換器１２の複数のロウ付け部である。本実施形態では、連通孔４６１は、複数のロウ付け部１２０のうち最も上方に位置する第１ロウ付け部１２１よりも上方に位置するので、空気よりも重い第１冷媒が漏洩しても、第１冷媒が連通孔４６１よりも上方に流れることを抑制している。 The second refrigerant is non-flammable, so there is little risk if it leaks, but the first refrigerant is flammable, so there is a risk of fire if the first refrigerant flows into the electrical equipment unit 420 (particularly the electrical equipment 42), which is a source of ignition. The locations where the first refrigerant is most likely to leak are the multiple brazed parts of the first heat exchanger 12. In this embodiment, the communication hole 461 is located above the first brazed part 121, which is the uppermost of the multiple brazed parts 120, so that even if the first refrigerant, which is heavier than air, leaks, the first refrigerant is prevented from flowing above the communication hole 461.
　さらに、ファン４４の駆動中には、連通孔４６１から第２室Ｓ２に流れる室外空気によって、漏洩した第１冷媒が第２室Ｓ２に流れることを抑制している。 Furthermore, while the fan 44 is running, the outside air flowing from the communication hole 461 into the second chamber S2 prevents the leaked first refrigerant from flowing into the second chamber S2.
　また、本実施形態のように電装品ユニット４２０（ここでは電装品４２）が上方に位置している場合は、連通孔４６１がケーシング４１内の上方に位置しているので、第２室Ｓ２に流入した室外空気は、電装品ユニット４２０（ここでは電装品４２）周りを通る。このため、電装品ユニット４２０（ここでは電装品４２）周りの室外空気を、第１室Ｓ１に流すことを促進できる。これにより、漏洩した第１冷媒が電装品４２周りに流れることを抑制している。 Furthermore, when the electrical equipment unit 420 (electrical equipment 42 in this embodiment) is located at the top, the communication hole 461 is located at the top inside the casing 41, so that the outside air that flows into the second chamber S2 passes around the electrical equipment unit 420 (electrical equipment 42 in this case). This can promote the flow of the outside air around the electrical equipment unit 420 (electrical equipment 42 in this case) into the first chamber S1. This prevents the leaked first refrigerant from flowing around the electrical equipment 42.
　また、第１冷媒が漏洩した場合、ベルマウス４５の筒状部の下端４５１より上方の第１冷媒は、ベルマウス４５の筒状部及びケーシング４１の吹出口を通って、ケーシング４１外に排出される。 In addition, if the first refrigerant leaks, the first refrigerant above the lower end 451 of the cylindrical portion of the bell mouth 45 passes through the cylindrical portion of the bell mouth 45 and the outlet of the casing 41 and is discharged outside the casing 41.
　（４）特徴
　（４－１）
　本実施形態に係る空調ユニットとしての室外ユニット２は、電装品ユニット４２０と、第１熱交換器１２と、第２熱交換器２３と、ファン４４と、ケーシング４１と、仕切板４６と、を備える。第１熱交換器１２は、燃焼性の第１冷媒と、空気とを熱交換させる。第２熱交換器２３は、非燃焼性の第２冷媒と、空気とを熱交換させる。ファン４４は、第１熱交換器１２及び第２熱交換器２３に空気を流す。ケーシング４１は、電装品ユニット４２０、第１熱交換器１２、第２熱交換器２３及びファン４４を収容する。仕切板４６は、ケーシング４１内を、第１熱交換器１２、第２熱交換器２３及びファン４４が配置される第１室Ｓ１と、電装品ユニット４２０が配置される第２室Ｓ２と、に仕切る。仕切板４６には、第１熱交換器１２の複数のロウ付け部１２０のうち最も上方に位置する第１ロウ付け部１２１よりも上方に、第１室Ｓ１と第２室Ｓ２とを連通させる連通孔４６１が設けられている。 (4) Features (4-1)
The outdoor unit 2 as an air conditioning unit according to this embodiment includes an electrical equipment 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 passes air through the first heat exchanger 12 and the second heat exchanger 23. The casing 41 houses the electrical equipment 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 casing 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 equipment unit 420 is arranged. The partition plate 46 has a communication hole 461 that connects the first chamber S1 and the second chamber S2 above the first brazed portion 121, which is the uppermost of the multiple brazed portions 120 of the first heat exchanger 12.
　本実施形態の空調ユニットとしての室外ユニット２では、仕切板４６に設けられた連通孔４６１及び第１室Ｓ１に配置されたファン４４により、電装品ユニット４２０が配置される第２室Ｓ２から、第１冷媒が流れる第１熱交換器１２が配置される第１室Ｓ１に空気を流すことができる。そして、燃焼性の第１冷媒が流れる第１熱交換器１２の最も高い位置Ｐ２にある第１ロウ付け部１２１よりも高い位置Ｐ１に連通孔４６１が設けられているので、第１室Ｓ１で第１冷媒が漏洩した場合であっても、連通孔４６１よりも上方に第１冷媒が流れることを抑制できる。したがって、第２室Ｓ２の電装品ユニット４２０を着火源とした発火の可能性を減らすことができる。特に、Ｒ２９０のような強燃性（Ａ３）冷媒の場合に、本空調ユニットは有用である。 In the outdoor unit 2 as the air conditioning unit of this embodiment, the communication hole 461 provided in the partition plate 46 and the fan 44 provided in the first chamber S1 allow air to flow from the second chamber S2 in which the electrical equipment unit 420 is arranged to the first chamber S1 in which the first heat exchanger 12 through which the first refrigerant flows is arranged. The communication hole 461 is provided at a position P1 higher than the first brazed portion 121 at the highest position P2 of the first heat exchanger 12 through which the flammable first refrigerant flows, so that even if the first refrigerant leaks in the first chamber S1, the first refrigerant can be prevented from flowing above the communication hole 461. Therefore, the possibility of ignition caused by the electrical equipment unit 420 in the second chamber S2 as an ignition source can be reduced. This air conditioning unit is particularly useful in the case of a highly flammable (A3) refrigerant such as R290.
　（４－２）
　本実施形態に係る空調ユニットとしての室外ユニット２は、上記（４－１）の室外ユニット２であって、連通孔４６１は、電装品ユニット４２０周りの空気をファンへ導くための孔である。 (4-2)
The outdoor unit 2 as an air conditioning unit according to this embodiment is the outdoor unit 2 described above in (4-1), and the communication hole 461 is a hole for guiding air around the electrical component unit 420 to the fan.
　ここでは、着火源となる電装品ユニット４２０周りの空気を、連通孔４６１を通じて、第１室Ｓ１に導くので、第１冷媒が漏洩した場合であっても、電装品ユニット４２０周りに第１冷媒が流れることを抑制できる。 Here, the air around the electrical equipment unit 420, which is a potential ignition source, is guided to the first chamber S1 through the communication hole 461, so that even if the first refrigerant leaks, the first refrigerant is prevented from flowing around the electrical equipment unit 420.
　（４－３）
　本実施形態に係る空調ユニットとしての室外ユニット２は、上記（４－１）または（４－２）の室外ユニット２であって、ベルマウス４５をさらに備える。ベルマウス４５は、第１室Ｓ１に配置され、ファン４４を囲む筒状部を有する。電装品ユニット４２０の下端４３１は、筒状部の下端４５１よりも上方に位置する。 (4-3)
The outdoor unit 2 as an air conditioning unit according to this embodiment is the outdoor unit 2 of (4-1) or (4-2) above, and further includes a bellmouth 45. The bellmouth 45 is disposed in the first chamber S1, and has a cylindrical portion surrounding the fan 44. A lower end 431 of the electrical component unit 420 is located above a lower end 451 of the cylindrical portion.
　ここでは、ベルマウス４５の筒状部の内側にファン４４が配置される。通常、第１冷媒は、空気よりも重いので、第１冷媒が漏洩した場合であっても、第１冷媒は筒状部の下端４５１よりも下方に滞留する。本実施形態では、電装品ユニット４２０（詳細には、電装品４２が取り付けられる基板４３）の下端４３１が筒状部の下端４５１よりも上方に位置しているので、仮に、仕切板４６の下端部と、ケーシング４１の底板４１３との間に隙間があって、第１冷媒が第２室Ｓ２に行ってしまったとしても、下方に溜まった第１冷媒が電装品ユニット４２０の高さレベルに到達することを抑制できる。 Here, the fan 44 is disposed inside the cylindrical portion of the bellmouth 45. Normally, the first refrigerant is heavier than air, so even if the first refrigerant leaks, the first refrigerant will accumulate below the lower end 451 of the cylindrical portion. In this embodiment, the lower end 431 of the electrical equipment unit 420 (specifically, the board 43 on which the electrical equipment 42 is mounted) is located above the lower end 451 of the cylindrical portion, so that even if there is a gap between the lower end of the partition plate 46 and the bottom plate 413 of the casing 41 and the first refrigerant goes into the second chamber S2, the first refrigerant accumulated below can be prevented from reaching the height level of the electrical equipment unit 420.
　（４－４）
　本実施形態に係る空調ユニットとしての室外ユニット２は、上記（４－１）から（４－３）のいずれかの室外ユニット２であって、電装品ユニット４２０は、第１ロウ付け部１２１よりも上方に位置する。 (4-4)
The outdoor unit 2 serving as an air conditioning unit according to this embodiment is any one of the outdoor units 2 described above in (4-1) to (4-3), in which the electrical component unit 420 is positioned above the first brazed portion 121.
　ここでは、第１冷媒が漏洩した場合であっても、第１冷媒は第１ロウ付け部１２１よりも下方に滞留する。ここでは、電装品ユニット４２０が第１ロウ付け部１２１よりも上方に位置しているので、第１冷媒が電装品に流れることをより抑制できる。 Here, even if the first refrigerant leaks, the first refrigerant will remain below the first brazed portion 121. Here, because the electrical equipment unit 420 is located above the first brazed portion 121, the first refrigerant can be further prevented from flowing to the electrical equipment.
　（４－５）
　本実施形態に係る空調ユニットとしての室外ユニット２は、上記（４－１）から（４－４）のいずれかの室外ユニット２であって、第１熱交換器１２は、第２熱交換器２３よりも下方に位置する。 (4-5)
The outdoor unit 2 as an air conditioning unit according to this embodiment is any one of the outdoor units 2 described above in (4-1) to (4-4), in which the first heat exchanger 12 is positioned below the second heat exchanger 23.
　ここでは、燃焼性の冷媒が流れる第１熱交換器１２は、非燃焼性の冷媒が流れる第２熱交換器２３よりも下方に配置される。このため、第１冷媒が漏洩した場合であっても、第１冷媒が下方に滞留しやすいので、連通孔４６１と第１ロウ付け部１２１との距離をとれるため、第１冷媒が電装品ユニット４２０に流れることを抑制する室外ユニット２を容易に実現できる。 Here, the first heat exchanger 12, through which the flammable refrigerant flows, is positioned below the second heat exchanger 23, through which the non-flammable refrigerant flows. Therefore, even if the first refrigerant leaks, the first refrigerant is likely to remain below, and since a distance can be maintained between the communication hole 461 and the first brazed portion 121, an outdoor unit 2 that prevents the first refrigerant from flowing into the electrical equipment unit 420 can be easily realized.
　（４－６）
　本実施形態に係る空調ユニットとしての室外ユニット２は、上記（４－１）から（４－５）のいずれかの室外ユニット２であって、第１圧縮機１１と、第２圧縮機２１と、ベルマウス４５と、をさらに備える。第１圧縮機１１は、第２室Ｓ２に配置され、第１冷媒を圧縮する。第２圧縮機２１は、第２室Ｓ２に配置され、第２冷媒を圧縮する。ベルマウス４５は、第１室Ｓ１に配置され、ファン４４を囲む筒状部を有する。第１圧縮機１１の第１ターミナル１１１及び第２圧縮機２１の第２ターミナル２１１は、筒状部の下端４５１よりも上方に位置する。 (4-6)
The outdoor unit 2 as an air conditioning unit according to this embodiment is the outdoor unit 2 according to any one of (4-1) to (4-5) above, and further includes a first compressor 11, a second compressor 21, and a bell mouth 45. The first compressor 11 is disposed in the second chamber S2 and compresses a first refrigerant. The second compressor 21 is disposed in the second chamber S2 and compresses a second refrigerant. The bell mouth 45 is disposed 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 a lower end 451 of the cylindrical portion.
　ここでは、第１冷媒が漏洩した場合であっても、第１冷媒はベルマウス４５の筒状部の下端４５１よりも下方に滞留する。ここでは、第１ターミナル１１１及び第２ターミナル２１１が筒状部の下端４５１よりも上方に位置しているので、第２室Ｓ２の第１ターミナル１１１及び第２ターミナル２１１を着火源とした発火の可能性を減らすことができる。 Here, even if the first refrigerant leaks, the first refrigerant will remain below the lower end 451 of the cylindrical portion of the bell mouth 45. Here, the first terminal 111 and the second terminal 211 are located above the lower end 451 of the cylindrical portion, so the possibility of ignition caused by the first terminal 111 and the second terminal 211 of the second chamber S2 as an ignition source can be reduced.
　（４－７）
　本実施形態に係る空調ユニットとしての室外ユニット２は、上記（４－１）から（４－５）のいずれかの室外ユニット２であって、第２冷媒は、二酸化炭素を含む。 (4-7)
The outdoor unit 2 as an air conditioning unit according to this embodiment is any one of the outdoor units 2 described above in (4-1) to (4-5), and the second refrigerant contains carbon dioxide.
　二酸化炭素冷媒は、ＧＷＰ（地球温暖化係数）が低いので、地球温暖化への低減により寄与する室外ユニット２を実現できる。 Since carbon dioxide refrigerant has a low GWP (global warming potential), it is possible to create an outdoor unit 2 that contributes more to reducing global warming.
　（５）変形例
　（５－１）変形例１
　上記実施形態では、空調ユニットは、二元冷凍サイクル装置１の室外ユニット２であるが、これに限定されない。本開示の空調ユニットは、室内ユニットやカスケードユニットであってもよい。 (5) Modifications (5-1) Modification 1
In the above embodiment, the air conditioning unit is the outdoor unit 2 of the cascade refrigeration cycle apparatus 1, but is not limited thereto. The air conditioning unit of the present disclosure may be an indoor unit or a cascade unit.
　（５－２）変形例２
　上記実施形態では、１つの室外ユニット２に対して１つの室内ユニット３が接続された二元冷凍サイクル装置１を例に挙げて説明したが、これに限定されない。本変形例の二元冷凍サイクル装置は、１つの室外ユニットに対して、複数の室内ユニットが接続される。 (5-2) Modification 2
In the above embodiment, the cascade refrigeration cycle apparatus 1 in which one indoor unit 3 is connected to one outdoor unit 2 has been described as an example, but is not limited thereto. In the cascade refrigeration cycle apparatus of this modified example, multiple indoor units are connected to one outdoor unit.
　（５－３）変形例３
　上記実施形態では、冷房運転及び暖房運転を行う二元冷凍サイクル装置１の空調ユニットを例に挙げて説明したが、これに限定されない。本開示の空調ユニットを備える二元冷凍サイクル装置は、除湿運転をさらに行ってもよい。また、本開示の空調ユニットを備える二元冷凍サイクル装置は、冷房専用の空気調和装置であってもよい。 (5-3) Modification 3
In the above embodiment, the air conditioning unit of the cascade refrigeration cycle apparatus 1 performing cooling operation and heating operation has been described as an example, but the present invention is not limited thereto. The cascade refrigeration cycle apparatus including the air conditioning unit of the present disclosure may further perform a dehumidification operation. In addition, the cascade refrigeration cycle apparatus including the air conditioning unit of the present disclosure may be an air conditioner dedicated to cooling.
　以上、本開示の実施形態を説明したが、特許請求の範囲に記載された本開示の趣旨及び範囲から逸脱することなく、形態や詳細の多様な変更が可能なことが理解されるであろう。 　Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the present disclosure as set forth in the claims.
１　　　：二元冷凍サイクル装置
２　　　：室外ユニット（空調ユニット）
３　　　：室内ユニット
１１　　：第１圧縮機
１２　　：第１熱交換器
２１　　：第２圧縮機
２３　　：第２熱交換器
２５　　：第３熱交換器
３０　　：カスケード熱交換器
４１　　：ケーシング
４２　　：電装品
４３　　：基板
４４　　：ファン
４５　　：ベルマウス
４６　　：仕切板
１１１、２１１：ターミナル
１２０　：ロウ付け部
１２１　：第１ロウ付け部
４２０　：電装品ユニット
４３１、４５１：下端
４６１　：連通孔
Ｓ１　　：第１室
Ｓ２　　：第２室 1: Dual refrigeration cycle device 2: Outdoor unit (air conditioning unit)
3: Indoor unit 11: First compressor 12: First heat exchanger 21: Second compressor 23: Second heat exchanger 25: Third heat exchanger 30: Cascade heat exchanger 41: Casing 42: Electrical components 43: Board 44: Fan 45: Bell mouth 46: Partition plate 111, 211: Terminal 120: Brazed portion 121: First brazed portion 420: Electrical component unit 431, 451: Lower end 461: Communication hole S1: First chamber S2: Second chamber
特許第５４３０６０４号Patent No. 5430604

Claims (6)

  1. 　電装品ユニット（４２０）と、
    　燃焼性の第１冷媒と、空気とを熱交換させる第１熱交換器（１２）と、
    　非燃焼性の第２冷媒と、空気とを熱交換させる第２熱交換器（２３）と、
    　前記第１熱交換器及び前記第２熱交換器に空気を流すファン（４４）と、
    　前記電装品ユニット、前記第１熱交換器、前記第２熱交換器及び前記ファンを収容するケーシング（４１）と、
    　前記ケーシング内を、前記第１熱交換器、前記第２熱交換器及び前記ファンが配置される第１室（Ｓ１）と、前記電装品ユニットが配置される第２室（Ｓ２）と、に仕切る仕切板（４６）と、
    を備え、
    　前記仕切板には、前記第１熱交換器の複数のロウ付け部（１２０）のうち最も上方に位置する第１ロウ付け部（１２１）よりも上方に、前記第１室と前記第２室とを連通させる連通孔（４６１）が設けられている、
    空調ユニット（２）。     An electrical equipment unit (420);
    a first heat exchanger (12) for exchanging heat between a combustible first refrigerant and air;
    a second heat exchanger (23) for exchanging heat between a non-flammable second refrigerant and air;
    a fan (44) for blowing air through the first heat exchanger and the second heat exchanger;
    a casing (41) that houses the electrical equipment unit, the first heat exchanger, the second heat exchanger, and the fan;
    a partition plate (46) that divides the inside of the casing into a first chamber (S1) in which the first heat exchanger, the second heat exchanger, and the fan are disposed, and a second chamber (S2) in which the electrical equipment unit is disposed;
    Equipped with
    The partition plate is provided with a communication hole (461) that communicates between the first chamber and the second chamber, above a first brazed portion (121) that is located at the uppermost position among the plurality of brazed portions (120) of the first heat exchanger.
    Air conditioning unit (2).
  2. 　前記連通孔は、前記電装品ユニット周りの空気を前記ファンへ導くための孔である、
    請求項１に記載の空調ユニット。     The communication hole is a hole for guiding air around the electrical equipment unit to the fan.
    2. An air conditioning unit according to claim 1.
  3. 　前記第１室に配置され、前記ファンを囲む筒状部を有するベルマウス（４５）をさらに備え、
    　前記電装品ユニットの下端（４３１）は、前記筒状部の下端（４５１）よりも上方に位置する、
    請求項１または２に記載の空調ユニット。     The fan further includes a bell mouth (45) disposed in the first chamber and having a cylindrical portion surrounding the fan,
    The lower end (431) of the electrical equipment unit is located above the lower end (451) of the cylindrical portion.
    An air conditioning unit according to claim 1 or 2.
  4. 　前記電装品ユニットの下端（４３１）は、前記第１ロウ付け部よりも上方に位置する、
    請求項１～３のいずれか１項に記載の空調ユニット。     A lower end (431) of the electrical equipment unit is located above the first brazed portion.
    An air conditioning unit according to any one of claims 1 to 3.
  5. 　前記第１熱交換器は、前記第２熱交換器よりも下方に位置する、
    請求項１～４のいずれか１項に記載の空調ユニット。     The first heat exchanger is located below the second heat exchanger.
    An air conditioning unit according to any one of the preceding claims.
  6. 　前記第２室に配置され、前記第１冷媒を圧縮する第１圧縮機（１１）と、
    　前記第２室に配置され、前記第２冷媒を圧縮する第２圧縮機（２１）と、
    　前記第１室に配置され、前記ファンを囲む筒状部を有するベルマウス（４５）と、
    をさらに備え、
    　前記第１圧縮機のターミナル（１１１）及び前記第２圧縮機のターミナル（２１１）は、前記筒状部の下端（４５１）よりも上方に位置する、
    請求項１～５のいずれか１項に記載の空調ユニット。     a first compressor (11) disposed in the second chamber and compressing the first refrigerant;
    a second compressor (21) disposed in the second chamber and compressing the second refrigerant;
    A bellmouth (45) disposed in the first chamber and having a cylindrical portion surrounding the fan;
    Further equipped with
    The terminal (111) of the first compressor and the terminal (211) of the second compressor are located above the lower end (451) of the cylindrical portion.
    An air conditioning unit according to any one of the preceding claims.
PCT/JP2023/041728 2022-12-12 2023-11-21 Air conditioning unit WO2024127924A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP23864106.2A EP4407243A1 (en) 2022-12-12 2023-11-21 Air conditioning unit

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-198099 2022-12-12
JP2022198099A JP7518418B2 (en) 2022-12-12 2022-12-12 Air conditioning unit

Publications (1)

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WO2024127924A1 true WO2024127924A1 (en) 2024-06-20

Family

ID=90481893

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Application Number Title Priority Date Filing Date
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JP (1) JP7518418B2 (en)
WO (1) WO2024127924A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010053874A (en) * 2009-12-11 2010-03-11 Panasonic Corp Hermetic electric compressor
JP2012172890A (en) * 2011-02-21 2012-09-10 Mitsubishi Electric Corp Refrigerating apparatus
JP2014006027A (en) * 2012-06-27 2014-01-16 Mitsubishi Electric Corp Refrigeration cycle device
JP5430604B2 (en) 2011-04-08 2014-03-05 三菱電機株式会社 Dual refrigeration equipment
US20150338145A1 (en) * 2014-05-22 2015-11-26 Lg Electronics Inc. Heat pump
WO2022013976A1 (en) * 2020-07-15 2022-01-20 三菱電機株式会社 Outdoor unit for refrigeration device and refrigeration device comprising same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010053874A (en) * 2009-12-11 2010-03-11 Panasonic Corp Hermetic electric compressor
JP2012172890A (en) * 2011-02-21 2012-09-10 Mitsubishi Electric Corp Refrigerating apparatus
JP5430604B2 (en) 2011-04-08 2014-03-05 三菱電機株式会社 Dual refrigeration equipment
JP2014006027A (en) * 2012-06-27 2014-01-16 Mitsubishi Electric Corp Refrigeration cycle device
US20150338145A1 (en) * 2014-05-22 2015-11-26 Lg Electronics Inc. Heat pump
WO2022013976A1 (en) * 2020-07-15 2022-01-20 三菱電機株式会社 Outdoor unit for refrigeration device and refrigeration device comprising same

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