US20250389432A1 - Heat exchanger and refrigeration cycle apparatus - Google Patents

Heat exchanger and refrigeration cycle apparatus

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Publication number
US20250389432A1
US20250389432A1 US18/880,197 US202218880197A US2025389432A1 US 20250389432 A1 US20250389432 A1 US 20250389432A1 US 202218880197 A US202218880197 A US 202218880197A US 2025389432 A1 US2025389432 A1 US 2025389432A1
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US
United States
Prior art keywords
refrigerant
heat exchanger
tube
end portion
flat tubes
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
US18/880,197
Other languages
English (en)
Inventor
Shingo KASAKI
Tetsuji Saikusa
Yoji ONAKA
Yuki NAKAO
Rihito ADACHI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Publication of US20250389432A1 publication Critical patent/US20250389432A1/en
Pending legal-status Critical Current

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Classifications

    • 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
    • F25B39/00—Evaporators; Condensers
    • F25B39/04—Condensers
    • 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
    • F24F1/14—Heat exchangers specially adapted for separate outdoor units
    • F24F1/18—Heat exchangers specially adapted for separate outdoor units characterised by their shape
    • 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
    • F25B6/00—Compression machines, plants or systems, with several condenser circuits
    • F25B6/04—Compression machines, plants or systems, with several condenser circuits arranged in series
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
    • F28D1/0408—Multi-circuit heat exchangers, e.g. integrating different heat exchange sections in the same unit or heat exchangers for more than two fluids
    • F28D1/0426—Multi-circuit heat exchangers, e.g. integrating different heat exchange sections in the same unit or heat exchangers for more than two fluids with units having particular arrangement relative to the large body of fluid, e.g. with interleaved units or with adjacent heat exchange units in common air flow or with units extending at an angle to each other or with units arranged around a central element
    • F28D1/0443—Combination of units extending one beside or one above the other
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D1/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators
    • F28D1/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid
    • F28D1/04—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits
    • F28D1/053—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, in which the other heat-exchange medium is a large body of fluid, e.g. domestic or motor car radiators with heat-exchange conduits immersed in the body of fluid with tubular conduits the conduits being straight
    • F28D1/05316—Assemblies of conduits connected to common headers, e.g. core type radiators
    • F28D1/05341—Assemblies of conduits connected to common headers, e.g. core type radiators with multiple rows of conduits or with multi-channel conduits combined with a particular flow pattern, e.g. multi-row multi-stage radiators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
    • F28F9/02—Header boxes; End plates
    • F28F9/026—Header boxes; End plates with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits
    • F28F9/027—Header boxes; End plates with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits in the form of distribution pipes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
    • F28F9/02—Header boxes; End plates
    • F28F9/026—Header boxes; End plates with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits
    • F28F9/027—Header boxes; End plates with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits in the form of distribution pipes
    • F28F9/0273—Header boxes; End plates with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits in the form of distribution pipes with multiple holes
    • 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
    • F25B2339/00—Details of evaporators; Details of condensers
    • F25B2339/04—Details of condensers
    • F25B2339/044—Condensers with an integrated receiver
    • F25B2339/0446—Condensers with an integrated receiver characterised by the refrigerant tubes connecting the header of the condenser to the receiver; Inlet or outlet connections to receiver
    • 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
    • F25B2339/00—Details of evaporators; Details of condensers
    • F25B2339/04—Details of condensers
    • F25B2339/045—Condensers made by assembling a tube on a plate-like element or between plate-like elements
    • 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
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/40—Fluid line arrangements
    • F25B41/42—Arrangements for diverging or converging flows, e.g. branch lines or junctions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
    • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
    • F28D2021/008—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for vehicles
    • F28D2021/0084—Condensers

Definitions

  • the present disclosure relates to a heat exchanger and a refrigeration cycle apparatus that have a plurality of flat tubes.
  • some refrigeration cycle apparatus includes a plurality of groups of heat exchangers, with one or more heat exchangers defined as one group.
  • Such a refrigeration cycle apparatus is referable to, for example, Patent Literature 1.
  • the heat exchanger in each of the plurality of groups is an air heat exchanger and has an upper header tube, a lower header tube, heat transfer tubes, and fins.
  • groups are connected in series to each other and a series refrigerant flow passage is thus formed through which refrigerant is caused to flow in series between groups.
  • All the heat exchangers in the series refrigerant flow passage each have heat transfer tubes through which refrigerant is caused to flow from above to below.
  • groups are connected in parallel to each other and a parallel refrigerant flow passage is thus formed through which refrigerant is caused to flow in parallel to respective groups.
  • All the heat exchangers in the parallel refrigerant flow passage each have heat transfer tubes through which refrigerant is caused to flow from below to above.
  • a refrigerant distributor structured with a double tube provided with an inner tube and an outer tube is used as a lower header, for example.
  • a plurality of outer tubes are provided. Between outer tubes adjacent to each other among the plurality of outer tubes, a gap is defined.
  • a single inner tube is provided and sequentially connected to the plurality of outer tubes.
  • a plurality of heat transfer tubes are connected in a tubular-axial direction of the outer tubes. Refrigerant that has flowed between the inner tube and the outer tubes is distributed to the plurality of heat transfer tubes.
  • Patent Literature 1 International Publication No. 2019/008664
  • a case in which a heat exchanger serves as an evaporator refrigerant in a two-phase gas-liquid state in which gas refrigerant and liquid refrigerant is mixed to each other flows into the heat exchanger.
  • a refrigerant distributor located on an inflow side of the heat exchanger a refrigerant distributor structured with a double tube provided with an inner tube and an outer tube may be used.
  • a large number of refrigerant outflow holes are arranged in parallel to each other in the inner tube.
  • the refrigerant distributor structured with a double tube is formed such that refrigerant is evenly distributed to a plurality of heat transfer tubes included in a heat exchanger and the refrigerant distributor is reduced in capacity.
  • a refrigerant distributor structured with a single tube is provided on an outflow side of a heat exchanger that serves as an evaporator.
  • the refrigerant distributor has the function of distributing refrigerant to a plurality of heat transfer tubes included in the heat exchanger.
  • connection states between the plurality of heat exchangers are distinguished between a case in which the series refrigerant flow passage is formed and a case in which the parallel refrigerant flow passage is formed.
  • the plurality of heat exchangers mounted on the outdoor unit each serve as a condenser and the plurality of heat exchangers form with each other the series refrigerant flow passage, a heat exchanger located upstream in a flow passage and a heat exchanger located downstream are different in a state of refrigerant that flows in.
  • gas refrigerant which is in a single phase, flows.
  • refrigerant in a two-phase gas-liquid state in which gas refrigerant and liquid refrigerant is mixed to each other flows because a portion of the gas refrigerant exchanges heat and thus condenses in the heat exchanger located upstream.
  • the refrigerant distributor on an inflow side of the heat exchanger located downstream in this case, however, is a refrigerant distributor structured with a single tube. In the heat exchanger located downstream, refrigerant caused to flow in is thus not evenly distributed to the plurality of flat tubes included in the heat exchanger.
  • the amounts of the distributed refrigerant vary at different locations of flat tubes.
  • the heat exchange amount is insufficient around the flat tubes into which a large amount of refrigerant is distributed.
  • the heat exchange amount is excessive around the flat tubes into which a small amount of refrigerant is distributed. Such an uneven distribution causes a problem in that efficiency of heat exchange is reduced.
  • the present disclosure is made to solve such a problem, and an object of the present disclosure is to provide a refrigeration cycle apparatus and a heat exchanger that is one heat exchanger among a plurality of heat exchangers that each serve as a condenser in cooling operation and is provided with a refrigerant distributor that evenly distributes refrigerant to a plurality of flat tubes also in a case in which, when the plurality of heat exchangers are connected in series to each other and a series refrigerant flow passage is thus formed, the heat exchanger is located downstream in a direction through refrigerant flows.
  • a heat exchanger includes a first heat exchange body that has a plurality of first flat tubes arranged and spaced from each other in a first direction and each of which tube axis extends in a second direction that intersects the first direction; a first refrigerant distributor into which one end portion of each of the plurality of first flat tubes is inserted; and a second refrigerant distributor into which the other end portion of each of the plurality of first flat tubes is inserted, the first refrigerant distributor having a first outer tube that extends in the first direction and into which the one end portion of each of the plurality of first flat tubes is inserted, a first inner tube that extends in the first direction, is located inside the first outer tube, and has a plurality of first refrigerant outflow holes arranged and spaced from each other in the first direction, and a first partition plate joined to an internal wall of the first outer tube in a state in which the first inner tube passes through a plate thickness, the second refrigerant distributor having a second outer
  • a refrigeration cycle apparatus is provided with an outdoor unit, in which the outdoor unit is provided with the heat exchanger described above, a second heat exchanger, a refrigerant pipe through which the heat exchanger and the second heat exchanger are connected to each other, a housing that is box-shaped and houses the heat exchanger and the second heat exchanger inside, and an air-sending device located at a upper portion of the housing and configured to form a flow of air by being driven to rotate and blow out the air that passes through the heat exchanger and the second heat exchanger upward from an upper face of the housing, and the heat exchanger and the second heat exchanger are located along a part or all of four side faces of the housing.
  • the heat exchanger and the refrigeration cycle apparatus have a refrigerant distributor structured with a double tube and a plurality of refrigerant outflow holes arranged in parallel to each other in an inner tube of the refrigerant distributor. Also in a case, for example, in which refrigerant in a two-phase gas-liquid state is caused to flow into the heat exchanger, the refrigerant distributor is thus provided, such an uneven situation is therefore addressed in which refrigerant is unevenly distributed to a plurality of flat tubes. Also, refrigerant is thus evenly distributed to the plurality of flat tubes, which ensures that the required heat exchange amount is uniform across all faces of the heat exchange body and that a reduction in heat exchange efficiency is thus prevented.
  • FIG. 1 is a refrigerant circuit diagram that illustrates a configuration of a refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 2 is a perspective view that illustrates a connection state in which an outdoor heat exchanger 3 and an outdoor heat exchanger 4 are connected to each other in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 3 is a cross-sectional view that illustrates a configuration of the outdoor heat exchanger 3 illustrated in FIG. 2 .
  • FIG. 4 is a cross-sectional view that illustrates a configuration of the outdoor heat exchanger 4 illustrated in FIG. 2 .
  • FIG. 5 is a cross-sectional view that illustrates a configuration of a refrigerant distributor 31 provided in the outdoor heat exchanger 3 illustrated in FIG. 3 .
  • FIG. 6 is a cross-sectional view that illustrates a configuration of a refrigerant distributor 32 provided in the outdoor heat exchanger 3 illustrated in FIG. 3 .
  • FIG. 7 is a cross-sectional view that illustrates a configuration of a refrigerant distributor 41 provided in the outdoor heat exchanger 4 illustrated in FIG. 4 .
  • FIG. 8 is a cross-sectional view that illustrates a configuration of a refrigerant distributor 42 provided in the outdoor heat exchanger 4 illustrated in FIG. 4 .
  • FIG. 9 is a perspective view that illustrates a connection state in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each in a heating operation state are connected to each other in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 10 is a diagram that schematically illustrates distribution acts of refrigerant at the refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 11 is a diagram that schematically illustrates distribution acts of refrigerant at the refrigerant distributor 32 , 41 , 42 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 12 is a diagram that schematically illustrates the state of liquid refrigerant in the refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 13 is a diagram that schematically illustrates the state of liquid refrigerant in the refrigerant distributor 32 , 41 , 42 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 14 is a refrigerant circuit diagram that illustrates a configuration of a refrigeration cycle apparatus 100 according to Modification 1 of Embodiment 1.
  • FIG. 15 is a refrigerant circuit diagram that illustrates a configuration of the refrigeration cycle apparatus 100 according to Modification 1 of Embodiment 1.
  • FIG. 16 is a refrigerant circuit diagram that illustrates a configuration of a refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1.
  • FIG. 17 is a diagram that illustrates flows of refrigerant in a case in which the refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1 is in a cooling operation state.
  • FIG. 18 illustrates flows of refrigerant in a case in which the refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1 is in a heating operation state.
  • FIG. 19 is a perspective view that illustrates a connection state in which an outdoor heat exchanger 3 C and an outdoor heat exchanger 4 C are connected to each other in a refrigeration cycle apparatus 100 according to Embodiment 2.
  • FIG. 20 is a perspective view that illustrates an external view of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to Embodiment 3.
  • FIG. 21 includes plan views that schematically illustrate examples of a configuration of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to Embodiment 3.
  • FIG. 22 is a perspective view that illustrates an external view of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to Modification of Embodiment 3.
  • FIG. 23 is a plan view that schematically illustrates an example of a configuration of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to Modification of Embodiment 3.
  • Embodiments of a heat exchanger and a refrigeration cycle apparatus according to the present disclosure are described below with reference to drawings.
  • the present disclosure is not limited to embodiments described below and may be variously changed without departing from the spirit of the present disclosure.
  • the present disclosure also includes any combination of combinable configurations among configurations described in the embodiments and their modifications described below.
  • the same or equivalent elements are denoted by the same reference signs in the drawings. Their descriptions are omitted or simplified as long as resultant descriptions are suited.
  • components or elements not required to be to distinguished or specified in particular may be described without such suffixes.
  • each outdoor heat exchanger has a width direction referred to as an X direction, a height direction referred to as a Z direction, and a front-rear direction referred to as a Y direction.
  • the X direction and the Y direction are, for example, horizontal directions.
  • the Z direction is, for example, an up-down direction and may be a vertical direction in some cases.
  • the X direction is a direction in which a plurality of flat tubes are arranged.
  • the Z direction is an axial direction of the flat tube and a direction through which refrigerant flows.
  • the Y direction is a direction through which air flows.
  • the X direction may be referred to as a first direction or a third direction.
  • the Z direction may be referred to as a second direction.
  • FIG. 1 is a refrigerant circuit diagram that illustrates a configuration of a refrigeration cycle apparatus 100 according to Embodiment 1.
  • the refrigeration cycle apparatus 100 has an outdoor unit 101 and an indoor unit 201 and forms a refrigeration cycle such that the outdoor unit 101 and the indoor unit 201 are connected to each other by a refrigerant pipe 310 .
  • the refrigerant pipe 310 includes a plurality of refrigerant pipes 300 to 308 . These refrigerant pipes 300 to 308 described herein may be collectively referred to as the refrigerant pipe 310 .
  • the outdoor unit 101 and the indoor unit 201 are connected to each other at connection ports P 1 and P 2 .
  • the connection port P 1 and the connection port P 2 are each included in the refrigerant pipe 310 .
  • connection port P 1 is an inflow connection port through which refrigerant flows into the outdoor unit 101 when the refrigeration cycle apparatus 100 is in a cooling operation state and is also an outflow connection port through which refrigerant flows out from the outdoor unit 101 when the refrigeration cycle apparatus 100 is in a heating operation state.
  • the connection port P 2 is an outflow connection port through which refrigerant flows out from the outdoor unit 101 when the refrigeration cycle apparatus 100 is in a cooling operation state and is also an inflow connection port through which refrigerant flows into the outdoor unit 101 when the refrigeration cycle apparatus 100 is in a heating operation state.
  • Embodiment 1 describes that one outdoor unit 101 and one indoor unit 201 are provided; however, each of the number of the outdoor units 101 and the number of the indoor units 201 is not limited to one and may also be two or more.
  • a refrigerant circuit included in the refrigeration cycle apparatus 100 is filled with a refrigerant such as a fluorocarbon refrigerant and an HFO refrigerant.
  • Examples of a fluorocarbon refrigerant include an HFC refrigerant, which stands for fluorinated hydrocarbon or hydrofluorocarbon.
  • HFC refrigerant examples include difluoromethane, which is also referred to as HFC-32 and R32, pentafluoroethane, which is also referred to as HFC-125 and R125, 1,1,1-trifluoroethane, which is also referred to as HFC-143a and R143a, 1,1,1,2-tetrafluoroethane, which is also referred to as HFC-134a and R134a.
  • fluorocarbon refrigerant also include a refrigerant mixture in which HFC refrigerants described above are mixed with each other.
  • a refrigerant mixture include a refrigerant mixture R410A in which R32 and R125 are mixed with each other, a refrigerant mixture R407C in which R32, R125, and R134a are mixed with each other, and a refrigerant mixture R404A in which R125, R143a, and R134a are mixed with each other.
  • HFO refrigerant which stands for a hydrofluoroolefin refrigerant
  • HFO-1234yf HFO-1234ze(E)
  • HFO-1234ze(Z) HFO-1234ze(Z)
  • a refrigerant with which the refrigerant circuit included in the refrigeration cycle apparatus 100 is filled is not limited to the examples described above and any refrigerants used in a vapor-compression heat pump is also usable.
  • Specific examples of usable refrigerants include a CO2 refrigerant, an HC refrigerant, such as a propane refrigerant and an isobutane refrigerant, and an ammonia refrigerant.
  • the outdoor unit 101 has a compressor 1 , a four-way valve 2 , an outdoor heat exchanger 3 , an outdoor heat exchanger 4 , an expansion valve 5 , an expansion valve 6 , a solenoid valve 7 , a solenoid valve 8 , two outdoor air-sending devices 9 , an accumulator 10 , and the refrigerant pipes 300 to 306 through which these components are connected to each other.
  • the compressor 1 is a fluid machine configured to compress sucked low-pressure refrigerant and discharge the refrigerant as high-pressure refrigerant.
  • the compressor 1 is, for example, a rotary compressor or a scroll compressor.
  • the compressor 1 may also be, for example, a compressor of which rotational frequency is constant or a compressor of which rotational frequency is controllable with an inverter mounted.
  • the four-way valve 2 is a flow switching device provided at a discharge side of the compressor 1 and configured to switch between a circulation direction of refrigerant in the cooling operation state and a circulation direction of refrigerant in the heating operation state.
  • Four connection ports 2 a to 2 d included in the four-way valve 2 are each connected to its corresponding one of the compressor 1 , the outdoor heat exchanger 3 , the accumulator 10 , and the connection port P 1 at which the outdoor unit 101 and the indoor unit 201 are connected to each other.
  • connection port 2 a located toward the compressor 1 is selected to be connected to either the connection port 2 b located toward the outdoor heat exchanger 3 or the connection port 2 d located toward the connection port P 1 of the outdoor unit 101 .
  • an unselected connection port is connected to the connection port 2 c , which is connected to the accumulator 10 .
  • the connection port 2 a is connected to the connection port 2 b and the connection port 2 d is connected to the connection port 2 c .
  • the connection port 2 a is connected to the connection port 2 d and the connection port 2 b is connected to the connection port 2 c.
  • the outdoor heat exchanger 3 is a heat exchanger that allows refrigerant that flows inside and air to exchange heat with each other.
  • the outdoor heat exchanger 3 serves as a condenser in the cooling operation state and serves as an evaporator in the heating operation state.
  • the outdoor heat exchanger 3 is connected to the four-way valve 2 through the refrigerant pipe 300 .
  • the refrigerant pipe 300 is branched from between the outdoor heat exchanger 3 and the four-way valve 2 to the refrigerant pipe 301 .
  • the refrigerant pipe 301 is connected to the solenoid valve 8 .
  • the outdoor heat exchanger 3 has connection ports 3 a and 3 b , which are connected to the refrigerant pipes.
  • the connection port 3 a is connected to the four-way valve 2 .
  • connection port 3 b located across inside from the opposite connection port 3 a is connected to the expansion valve 5 through the refrigerant pipe 302 .
  • the refrigerant pipe 302 is branched from between the outdoor heat exchanger 3 and the expansion valve 5 to the refrigerant pipe 303 .
  • the refrigerant pipe 303 is connected to the solenoid valve 7 .
  • the outdoor heat exchanger 3 allows air that passes through and refrigerant that flows inside to exchange heat with each other.
  • the outdoor air-sending devices 9 are, for example, centrifugal fans, such as sirocco fans and turbo fans, cross-flow fans, diagonal-flow fans, or propeller fans.
  • the outdoor heat exchanger 3 described in the embodiments corresponds to a second heat exchanger.
  • the outdoor heat exchanger 4 is a heat exchanger that allows refrigerant that flows inside and air to exchange heat with each other.
  • the outdoor heat exchanger 4 serves as a condenser in the cooling operation state and serves as an evaporator in the heating operation state.
  • the outdoor heat exchanger 4 is connected to the solenoid valve 8 through the refrigerant pipe 301 .
  • the refrigerant pipe 301 is branched from between the outdoor heat exchanger 4 and the solenoid valve 8 to the refrigerant pipe 303 described above.
  • the outdoor heat exchanger 4 has connection ports 4 a and 4 b , which are connected to the refrigerant pipes.
  • the connection port 4 a is connected to the four-way valve 2 through the solenoid valve 8 .
  • connection port 4 b located across inside from the opposite connection port 4 a is connected to the expansion valve 6 through the refrigerant pipe 304 .
  • the outdoor heat exchanger 4 allows air that passes through and refrigerant that flows inside to exchange heat with each other.
  • the outdoor heat exchanger 4 described in the embodiments corresponds to a heat exchanger.
  • the refrigerant pipe 304 provided with the expansion valve 6 is joined to the refrigerant pipe 302 provided with expansion valve 5 .
  • a junction at which the refrigerant pipe 304 and the refrigerant pipe 302 are joined to each other is connected to the connection port P 2 .
  • the connection port P 2 is an outflow connection port through which refrigerant flows out from the outdoor unit 101 in the cooling operation state and is also an inflow connection port through which refrigerant flows into the outdoor unit 101 in the heating operation state.
  • the expansion valve 5 and the expansion valve 6 are each configured to serve as a pressure reducing valve or an expansion valve and reduce the pressure of refrigerant and thus expand the refrigerant.
  • the expansion valve 5 and the expansion valve 6 are each, for example, a pressure reducing device such as a linear electronic expansion valve of which opening degree is multi-stepwise or serially adjustable.
  • the solenoid valve 7 and the solenoid valve 8 are each configured to open and close a flow passage depending on whether voltage is applied.
  • the solenoid valve 7 and the solenoid valve 8 are configured block and open respective flows of refrigerant and thus switch flow passages of refrigerant.
  • the accumulator 10 is provided such that an outflow side of the accumulator 10 is connected to a suction side of the compressor 1 .
  • the accumulator 10 has the function of separating liquid refrigerant and gas refrigerant from each other and storing surplus refrigerant.
  • An inflow side of the accumulator 10 is connected to the connection port 2 c of the four-way valve 2 through the refrigerant pipe 306 .
  • a controller 11 controls acts of the compressor 1 , the four-way valve 2 , the expansion valve 5 , the expansion valve 6 , the solenoid valve 7 , the solenoid valve 8 , and the two outdoor air-sending devices 9 .
  • the controller 11 is formed by a processor circuit.
  • the processor circuit is formed by dedicated hardware or a processor. r.
  • Examples of the dedicated hardware include an application specific integrated circuit, which is also referred to as an ASIC, and a field programmable gate array, which is also referred to as an FPGA.
  • the processor executes a program stored in a memory.
  • the controller 11 has unillustrated memory circuitry.
  • the memory circuitry is formed by a memory.
  • the memory is non-volatile or volatile semiconductor memory such as a random access memory, which is also referred to as a RAM, a read only memory, which is also referred to as a ROM, a flash memory, and an erasable programmable ROM, which is also referred to as an EPROM, or a disk such as a magnetic disk, a flexible disk, and an optical disk.
  • a random access memory which is also referred to as a RAM
  • ROM read only memory
  • flash memory a flash memory
  • EPROM erasable programmable ROM
  • disk such as a magnetic disk, a flexible disk, and an optical disk.
  • the indoor unit 201 is formed by an indoor heat exchanger 21 , an indoor air-sending device 22 , an expansion valve 23 , and the refrigerant pipes 307 and 308 through which these components are connected to each other.
  • the indoor unit 201 forms, together with the outdoor unit 101 , a refrigeration cycle.
  • the indoor unit 201 supplies cooling energy or heating energy from the outdoor unit 101 to a cooling load or a heating load.
  • the cooling load and the heating load correspond to, for example, an indoor space in which the indoor unit 201 is located.
  • the indoor heat exchanger 21 is a heat exchanger that allows refrigerant that flows inside and air to exchange heat with each other.
  • the indoor heat exchanger 21 serves as an evaporator in the cooling operation state and serves as a condenser in the heating operation state.
  • the indoor heat exchanger 21 has connection ports 21 a and 21 b , which are connected to the refrigerant pipes.
  • the connection port 21 a is connected to the expansion valve 23 through the refrigerant pipe 307 .
  • the connection port 21 b located across inside from the opposite connection port 21 a is connected to the connection port P 1 through the refrigerant pipe 308 .
  • the indoor heat exchanger 21 allows air that passes through and refrigerant that flows inside to exchange heat with each other.
  • the indoor air-sending device 22 is, for example, a centrifugal fan, such as a sirocco fan and a turbo fan, a cross-flow fan, a diagonal-flow fan, or a propeller fan.
  • the expansion valve 23 is configured to serve as a pressure reducing valve or an expansion valve and reduce the pressure of refrigerant and thus expand the refrigerant.
  • the expansion valve 23 is, for example, a pressure reducing device such as a linear electronic expansion valve of which opening degree is multi-stepwise or serially adjustable.
  • the controller 11 exercises control such that the expansion valve 5 is in a fully closed state, the solenoid valve 7 is in an open state, the solenoid valve 8 is in a closed state, and the expansion valve 6 is in a fully open state.
  • the compressor 1 sucks in refrigerant from the accumulator 10 and then compresses the refrigerant.
  • the compressed refrigerant turns into gas refrigerant, is then discharged from the compressor 1 , and flows into the outdoor heat exchanger 3 through the four-way valve 2 .
  • the outdoor heat exchanger 3 a portion of the gas refrigerant condenses and the gas refrigerant then turns into a two-phase gas-liquid state of gas refrigerant and liquid refrigerant.
  • the refrigerant in a two-phase gas-liquid state passes through the solenoid valve 7 and then flows into the outdoor heat exchanger 4 .
  • the refrigerant compressed in the outdoor heat exchanger 4 turns into refrigerant in a liquid state.
  • the refrigerant in a liquid state passes through the expansion valve 6 , then flows out from the outdoor unit 101 , and flows into the indoor unit 201 .
  • the refrigerant is reduced in pressure in the expansion valve 23 , then evaporates in the indoor heat exchanger 21 , and supplies cooling energy to air.
  • the refrigerant flows out from the indoor unit 201 , then flows into the outdoor unit 101 , passes through the refrigerant pipe 305 , and flows into the four-way valve 2 . Subsequently, the refrigerant flows out from the four-way valve 2 , passes through the refrigerant pipe 306 , and flows into the accumulator 10 .
  • the refrigerant is then sucked from the accumulator 10 into the compressor 1 again and circulates in the refrigerant circuit. This operation establishes a refrigerant circuit that has a refrigerant flow passage through which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series to each other.
  • the controller 11 exercises control such that the expansion valve 5 is in a fully closed state, the solenoid valve 7 is in an open state, the solenoid valve 8 is in a closed state, and the expansion valve 6 is in a fully open state.
  • the compressor 1 sucks in refrigerant from the accumulator 10 and then compresses the refrigerant.
  • the compressed refrigerant turns into gas refrigerant, is then discharged from the compressor 1 , and flows out through the four-way valve 2 from the outdoor unit 101 into the indoor unit 201 .
  • the indoor unit 201 heat is exchanged at the indoor heat exchanger 21 and the refrigerant thus condenses.
  • the refrigerant flows into the expansion valve 23 and is then reduced in pressure in the expansion valve 23 .
  • the refrigerant flows out from the indoor unit 201 and then flows into the outdoor unit 101 .
  • the outdoor unit 101 the refrigerant flows into the outdoor heat exchanger 4 through the expansion valve 6 and then evaporates by heat exchange.
  • the refrigerant passes through the solenoid valve 7 and then flows into the outdoor heat exchanger 3 .
  • the refrigerant of which heat is further exchanged at the outdoor heat exchanger 3 turns into refrigerant in a gas state.
  • the refrigerant in a gas state flows into the four-way valve 2 . Subsequently, the refrigerant flows out from the four-way valve 2 , passes through the refrigerant pipe 306 , and flows into the accumulator 10 . The refrigerant is then sucked from the accumulator 10 into the compressor 1 again and circulates in the refrigerant circuit. This operation establishes a refrigerant circuit that has a refrigerant flow passage through which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series to each other.
  • a case is described in “Heating Operation State in Case of Series Refrigerant Flow Passage” in which a series refrigerant flow passage is formed in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series to each other.
  • a state of connection is not limited to such a case. That is, a configuration may also be established such that, depending on an operation state of the refrigeration cycle apparatus 100 , connection between the outdoor heat exchanger 3 and the outdoor heat exchanger 4 may also be switched to connection by use of a series refrigerant flow passage or connection by use of a parallel refrigerant flow passage.
  • a parallel refrigerant flow passage may also be formed in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in parallel to each other. This case is described later with reference to FIG. 14 and FIG. 15 .
  • FIG. 2 is a perspective view that illustrates a connection state in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected to each other in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 2 illustrates a case in which the refrigeration cycle apparatus 100 is in a cooling operation state.
  • FIG. 2 illustrates a refrigerant flow passage through which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series to each other, which is expressed by simple connection of refrigerant pipes.
  • Solid arrows illustrated in FIG. 2 each represent a direction in which refrigerant flows and outlined arrows illustrated in FIG. 2 each represent a direction of wind generated by its corresponding one of the outdoor air-sending devices 9 , that is, a direction of airflow.
  • FIG. 3 is a cross-sectional view that illustrates a configuration of the outdoor heat exchanger 3 illustrated in FIG. 2 .
  • FIG. 4 is a cross-sectional view that illustrates a configuration of the outdoor heat exchanger 4 illustrated in FIG
  • the outdoor heat exchanger 3 is formed by a refrigerant distributor 31 , a refrigerant distributor 32 , a plurality of heat exchange bodies 33 , and a reverse header 34 .
  • a refrigerant pipe 35 is connected to the refrigerant distributor 31 and a refrigerant pipe 36 is connected to the refrigerant distributor 32 .
  • the plurality of heat exchange bodies 33 includes, as illustrated in FIG. 3 , a heat exchange body 33 A and a heat exchange body 33 B.
  • the heat exchange body 33 A and the heat exchange body 33 B are arranged in a direction of airflow and face each other.
  • the heat exchange body 33 A and the heat exchange body 33 B are located such that the two heat exchange bodies form layers in a direction along a direction of wind generated by its corresponding one of the outdoor air-sending devices 9 .
  • a heat exchange body 33 located windward is referred to as the heat exchange body 33 B and a heat exchange body 33 located leeward is referred to as the heat exchange body 33 A.
  • the heat exchange body 33 A and the heat exchange body 33 B are basically the same in configuration and are thus collectively described below as the heat exchange body 33 .
  • the heat exchange body 33 is formed by a plurality of flat tubes 37 and a plurality of fins 38 .
  • the plurality of flat tubes 37 are spaced from each other and arranged in a horizontal direction, that is, the X direction. This configuration causes wind generated by its corresponding one of the outdoor air-sending devices 9 to flow between the flat tubes 37 , which are adjacent to each other, in a direction represented by its corresponding one of outlined arrows illustrated in FIG. 2 .
  • the axial direction of the plurality of flat tubes 37 is the Z direction. Refrigerant flows inside the flat tubes 37 in the Z direction. Refrigerant flows inside the flat tubes 37 and the refrigerant and air thus exchange heat with each other.
  • the fins 38 are arranged between the flat tubes 37 , which are adjacent to each other in the X direction.
  • the fins 38 are each joined to a side face portion of the flat tube 37 that is adjacent to the fin 38 and each transfer heat to the flat tube 37 .
  • the fin 38 such as a corrugated fin, is used to improve efficiency of heat exchange between air and refrigerant.
  • the fin 38 is, however, not limited to a corrugated fin and may also be, for example, a flat-plate fin.
  • air and refrigerant exchange heat with each other even at a surface of the flat tube 37 , and the fins 38 thus do not necessarily have to be provided.
  • the same fins 38 may also be shared among the plurality of heat exchange bodies 33 .
  • FIG. 5 is a cross-sectional view that illustrates a configuration of the refrigerant distributor 31 provided in the outdoor heat exchanger 3 illustrated in FIG. 3 .
  • FIG. 6 is a cross-sectional view that illustrates a configuration of the refrigerant distributor 32 provided in the outdoor heat exchanger 3 illustrated in FIG. 3 .
  • the plurality of flat tubes 37 included in the heat exchange body 33 A each have tube end portions 37 a and 37 b at both respective ends in the axial direction.
  • the refrigerant distributor 31 is provided under, between the tube end portions 37 a and 37 b , the tube end portion 37 a , which is lower than the tube end portion 37 b .
  • the refrigerant distributor 31 is, as illustrated in FIG. 5 , formed by an outer tube 51 and a connection tube 52 .
  • the refrigerant distributor 31 has a single-tube structure.
  • the outer tube 51 is a circular tube and its axial direction is the X direction. In an upper face portion of the outer tube 51 , a plurality of flat-tube insertion holes 51 e are provided.
  • the plurality of flat-tube insertion holes 51 e are spaced from each other and arranged in the X direction.
  • the plurality of flat-tube insertion holes 51 e are through holes that pass through the upper face portion of the outer tube 51 .
  • the tube end portion 37 a of each of the flat tubes 37 is directly inserted into a flat-tube insertion hole 51 e of the outer tube 51 .
  • the outer tube 51 has tube end portions 51 a and 51 b at both respective ends in the X direction. Between the tube end portions 51 a and 51 b , at the tube end portion 51 a , a closure plate 51 c is provided and, at the tube end portion 51 b , a closure plate 51 d is provided.
  • the tube end portion 51 a and the tube end portion 51 b are each in a closed state by the closure plate 51 c and the closure plate 51 d , respectively, and are not open.
  • connection tube 52 is, as illustrated in FIG. 5 , connected to the outer tube 51 .
  • An axial direction of the connection tube 52 is the Z direction.
  • a lower end portion 52 a of the connection tube 52 is inserted into the outer tube 51 .
  • An internal space in the connection tube 52 and an internal space in the outer tube 51 communicate with each other.
  • the refrigerant distributor 31 is, as illustrated in FIG. 2 , connected to the refrigerant pipe 35 .
  • the outer tube 51 of the refrigerant distributor 31 is connected to the refrigerant pipe 35 through the connection tube 52 .
  • An inside of the refrigerant distributor 31 is, as illustrated in FIG. 5 , one space formed by the internal space in the connection tube 52 and the internal space in the outer tube 51 .
  • Refrigerant having flowed from the refrigerant pipe 35 into the space inside the refrigerant distributor 31 is directly distributed to the plurality of flat tubes 37 included in the heat exchange body 33 A.
  • the outer tube 51 is herein illustrated as a shape of one circular cylinder with both ends closed by lids, which are the closure plates 51 c and 51 d ; however, a cross-sectional shape of the outer tube 51 does not necessarily have to be circular and may also be rectangular or elliptical. Also, the outer tube 51 does not necessarily have to be formed by one cylindrical part.
  • the outer tube 51 may also be divided into two portions such as an upper half into which the flat tubes 37 are inserted and the other half, that is, a lower half, and may also be formed by joining the upper half and the lower half to each other. The same also applies to an outer tube 53 , an outer tube 57 , and an outer tube 61 , which are described later.
  • the reverse header 34 On top of the tube end portions 37 b of the flat tubes 37 in the heat exchange body 33 A and on top of the tube end portions 37 b of the flat tubes 37 in the heat exchange body 33 B, the reverse header 34 is provided.
  • the heat exchange body 33 A is thus connected to the heat exchange body 33 B through the reverse header 34 .
  • the reverse header 34 has the function of reversing an upward flow of refrigerant into a downward flow by causing refrigerant having flowed in from the plurality of flat tubes 37 included in the heat exchange body 33 A to flow out into the plurality of flat tubes 37 included in the heat exchange body 33 B.
  • refrigerant flows from a lower position toward a higher position in the Z direction.
  • the reverse header 34 thus allows directions in which refrigerant flows to be switched.
  • An example is herein provided in which the flat tubes 37 located leeward and the flat tubes 37 located windward are connected through the reverse header 34 ; however, the configuration is not limited to such a case.
  • the flat tubes 37 may also not be divided into windward ones and leeward ones and may also be formed by one flat tube. The case in which the flat tube 37 is formed by one flat tube is described later in Embodiment 2 with reference to FIG. 19 .
  • the refrigerant distributor 32 is provided under the tube end portions 37 a , which are lower portions of the plurality of flat tubes 37 included in the heat exchange body 33 B.
  • the refrigerant distributor 32 is, as illustrated in FIG. 6 , formed by the outer tube 53 , an inner tube 54 , and a connection tube 56 .
  • the refrigerant distributor 32 has a double-tube structure.
  • the outer tube 53 is a circular tube and its axial direction is the X direction.
  • a plurality of flat-tube insertion holes 53 e are provided in an upper face portion of the outer tube 53 .
  • the plurality of flat-tube insertion holes 53 e are spaced from each other and arranged in the X direction.
  • the plurality of flat-tube insertion holes 53 e are through holes that pass through the upper face portion of the outer tube 53 .
  • the tube end portion 37 a of each of the flat tubes 37 is directly inserted into a flat-tube insertion hole 53 e of the outer tube 53 .
  • a closure plate 53 c is provided between the tube end portions 53 a and 53 b of the outer tube 53 , at the tube end portion 53 a , a closure plate 53 c is provided and, at the tube end portion 53 b , a closure plate 53 d is provided.
  • the tube end portion 53 a and the tube end portion 53 b are each in a closed state by the closure plate 53 c and the closure plate 53 d , respectively, and are not open.
  • connection tube 56 is, as illustrated in FIG. 6 , connected to the outer tube 53 .
  • An axial direction of the connection tube 56 is the Z direction.
  • a lower end portion 56 a of the connection tube 56 is inserted into the outer tube 53 .
  • An internal space in the connection tube 56 and a first internal space 53 g which is an internal space that faces the tube end portion 53 a of the outer tube 53 , communicate with each other.
  • a cross-sectional shape of the first internal space 53 g is circular.
  • the refrigerant distributor 32 is, as illustrated in FIG. 2 , connected to the refrigerant pipe 36 .
  • the outer tube 53 of the refrigerant distributor 32 is connected to the refrigerant pipe 36 through the connection tube 56 .
  • the refrigerant distributor 32 has a double-tube structure such that, inside the outer tube 53 , the inner tube 54 is located. Between an internal wall 53 f of the outer tube 53 and an external wall 54 f of the inner tube 54 , a gap is defined as a second internal space 53 h in the outer tube 53 .
  • a cross-sectional shape of the second internal space 53 h is doughnut-shaped, that is, ring-shaped.
  • the inner tube 54 is provided with a plurality of refrigerant outflow holes 54 c arranged in parallel to each other in a side face portion of the inner tube 54 .
  • the inner tube 54 is joined to the outer tube 53 with a partition plate 55 in between.
  • the partition plate 55 is located between the first internal space 53 g and the closure plate 53 d of the outer tube 53 .
  • the partition plate 55 partitions an area into the first internal space 53 g and the second internal space 53 h .
  • a through hole 55 a is formed in the central portion of the partition plate 55 .
  • the tube end portion 54 a is fitted into the through hole 55 a .
  • the tube end portion 54 a opens toward the first internal space 53 g .
  • the first internal space 53 g and an internal space in the inner tube 54 thus communicate with each other.
  • the tube end portion 54 b of the inner tube 54 is joined to the closure plate 53 d and is in a closed state.
  • An outer circumference portion of the partition plate 55 is joined to the internal wall 53 f of the outer tube 53 .
  • the partition plate 55 is, as described above, joined to the internal wall 53 f of the outer tube 53 and the external wall 54 f of the inner tube 54 .
  • the refrigerant that flows inside the refrigerant distributor 32 is thus allowed to pass through between the first internal space 53 g at the tube end portion 53 a to which the connection tube 56 is connected and the closure plate 53 d at the opposite tube end portion 53 b only through the internal space in the inner tube 54 .
  • the outdoor heat exchanger 4 is formed by a refrigerant distributor 41 , a refrigerant distributor 42 , a plurality of heat exchange bodies 43 , and a reverse header 44 .
  • the refrigerant pipe 36 is connected to the refrigerant distributor 41 and a refrigerant pipe 45 is connected to the refrigerant distributor 42 .
  • the plurality of heat exchange bodies 43 includes, as illustrated in FIG. 4 , a heat exchange body 43 A and a heat exchange body 43 B.
  • the heat exchange body 43 A and the heat exchange body 43 B are arranged in a direction of airflow and face each other.
  • the heat exchange body 43 A and the heat exchange body 43 B are located such that the two heat exchange bodies form layers in a direction along a direction of wind generated by its corresponding one of the outdoor air-sending devices 9 .
  • a heat exchange body 43 located windward is referred to as the heat exchange body 43 B and a heat exchange body 43 located leeward is referred to as the heat exchange body 43 A.
  • the heat exchange body 43 A and the heat exchange body 43 B are basically the same in configuration and are thus collectively described below as the heat exchange body 43 .
  • the heat exchange body 43 is formed by a plurality of flat tubes 47 and a plurality of fins 48 .
  • the plurality of flat tubes 47 are spaced from each other and arranged in a horizontal direction, that is, the X direction. This configuration causes wind generated by its corresponding one of the outdoor air-sending devices 9 to flow between the flat tubes 47 , which are adjacent to each other, in a direction represented by its corresponding one of outlined arrows illustrated in FIG. 2 .
  • the axial direction of the plurality of flat tubes 47 is the Z direction. Refrigerant flows inside the flat tubes 47 in the Z direction. Refrigerant flows inside the flat tubes 47 and the refrigerant and air thus exchange heat with each other.
  • the fins 48 are arranged between the flat tubes 47 , which are adjacent to each other in the X direction.
  • the fins 48 are each joined to a side face portion of the flat tube 47 that is adjacent to the fin 48 and each transfer heat to the flat tube 47 .
  • the fin 48 such as a corrugated fin, is used to improve efficiency of heat exchange between air and refrigerant.
  • the fin 48 is, however, not limited to a corrugated fin and may also be, for example, a flat-plate fin. Also, air and refrigerant exchange heat with each other even at a surface of the flat tube 47 , and the fins 48 thus do not necessarily have to be provided. In a case in which the plurality of heat exchange bodies 43 have fins 48 , the same fins 48 may also be shared among the plurality of heat exchange bodies 43 .
  • FIG. 7 is a cross-sectional view that illustrates a configuration of the refrigerant distributor 41 provided in the outdoor heat exchanger 4 illustrated in FIG. 4 .
  • FIG. 8 is a cross-sectional view that illustrates a configuration of the refrigerant distributor 42 provided in the outdoor heat exchanger 4 illustrated in FIG. 4 .
  • the refrigerant distributor 41 is provided under, between the tube end portions 47 a and 47 b of each of the plurality of flat tubes 47 included in the heat exchange body 43 A, the tube end portion 47 a , which is lower than the tube end portion 47 b .
  • the refrigerant distributor 41 is, as illustrated in FIG. 7 , formed by the outer tube 57 , an inner tube 58 , and a connection tube 60 .
  • the refrigerant distributor 41 has a double-tube structure.
  • the outer tube 57 is a circular tube and its axial direction is the X direction.
  • a plurality of flat-tube insertion holes 57 e are provided in an upper face portion of the outer tube 57 .
  • the plurality of flat-tube insertion holes 57 e are spaced from each other and arranged in the X direction.
  • the plurality of flat-tube insertion holes 57 e are through holes that pass through the upper face portion of the outer tube 57 .
  • the tube end portion 47 a of each of the flat tubes 47 is directly inserted into a flat-tube insertion hole 57 e of the outer tube 57 .
  • a closure plate 57 c is provided between the tube end portions 57 a and 57 b of the outer tube 57 , at the tube end portion 57 a , a closure plate 57 c is provided and, at the tube end portion 57 b , a closure plate 57 d is provided.
  • the tube end portion 57 a and the tube end portion 57 b are each in a closed state by the closure plate 57 c and the closure plate 57 d , respectively, and are not open.
  • connection tube 60 is, as illustrated in FIG. 7 , connected to the outer tube 57 .
  • An axial direction of the connection tube 60 is the Z direction.
  • a lower end portion 60 a of the connection tube 60 is inserted into the outer tube 57 .
  • An internal space in the connection tube 60 and a first internal space 57 g which is an internal space that faces the tube end portion 57 a of the outer tube 57 , communicate with each other.
  • a cross-sectional shape of the first internal space 57 g is circular.
  • the refrigerant distributor 41 is, as illustrated in FIG. 2 , connected to the refrigerant pipe 36 .
  • the outer tube 57 of the refrigerant distributor 41 is connected to the refrigerant pipe 36 through the connection tube 60 .
  • the refrigerant distributor 41 has a double-tube structure such that, inside the outer tube 57 , the inner tube 58 is located. Between an internal wall 57 f of the outer tube 57 and an external wall 58 f of the inner tube 58 , a gap is defined as a second internal space 57 h in the outer tube 57 .
  • a cross-sectional shape of the second internal space 57 h is doughnut-shaped, that is, ring-shaped.
  • the inner tube 58 is provided with a plurality of refrigerant outflow holes 58 c arranged in parallel to each other in a side face portion of the inner tube 58 .
  • An inner diameter of the refrigerant outflow hole 58 c may also be the same as or different from an inner diameter of the refrigerant outflow hole 54 c illustrated in FIG. 6 and the inner diameter of the refrigerant outflow hole 62 c illustrated in FIG. 8 .
  • the inner tube 58 is joined to the outer tube 57 with a partition plate 59 in between.
  • the partition plate 59 is located between the first internal space 57 g and the closure plate 57 d of the outer tube 57 .
  • the partition plate 59 partitions an area into the first internal space 57 g and the second internal space 57 h . In the central portion of the partition plate 59 , a through hole 59 a is formed.
  • the tube end portion 58 a is fitted into the through hole 59 a .
  • the tube end portion 58 a opens toward the first internal space 57 g .
  • the first internal space 57 g and an internal space in the inner tube 58 thus communicate with each other.
  • the tube end portion 58 b of the inner tube 58 is joined to the closure plate 57 d and is in a closed state.
  • An outer circumference portion of the partition plate 59 is joined to the internal wall 57 f of the outer tube 57 .
  • the partition plate 59 is, as described above, joined to the internal wall 57 f of the outer tube 57 and the external wall 58 f of the inner tube 58 .
  • the refrigerant that flows inside the refrigerant distributor 41 is thus allowed to pass through between the first internal space 57 g at the tube end portion 57 a to which the connection tube 60 is connected and the closure plate 57 d at the opposite tube end portion 58 b only through the internal space in the inner tube 58 .
  • the reverse header 44 On top of the tube end portions 47 b that are upper ends of the flat tubes 47 in the heat exchange body 43 A and on top of the tube end portions 47 b that are upper ends of the flat tubes 47 in the heat exchange body 43 B, the reverse header 44 is provided.
  • the heat exchange body 43 A is thus connected to the heat exchange body 43 B through the reverse header 44 .
  • the reverse header 44 has the function of reversing an upward flow of refrigerant into a downward flow by causing refrigerant having flowed in from the plurality of flat tubes 47 included in the heat exchange body 43 A to flow out into the plurality of flat tubes 47 included in the heat exchange body 43 B.
  • the plurality of flat tubes 47 included in the heat exchange body 43 A refrigerant flows from a lower position toward a higher position in the Z direction.
  • the plurality of flat tubes 47 included in the heat exchange body 43 B refrigerant flows from a higher position toward a lower position in the Z direction.
  • the reverse header 44 thus allows directions in which refrigerant flows to be switched.
  • An example is herein provided in which the flat tubes 47 located leeward and the flat tubes 47 located windward are connected through the reverse header 44 ; however, the configuration is not limited to such a case.
  • the flat tubes 47 may also not be divided into windward ones and leeward ones and may also be formed by one flat tube. The case in which the flat tube 47 is formed by one flat tube is described later in Embodiment 2 with reference to FIG. 19 .
  • the refrigerant distributor 42 is provided under, between the tube end portions 47 a and 47 b of each of the plurality of flat tubes 47 included in the heat exchange body 43 B, the tube end portion 47 a , which is lower than the tube end portion 47 b .
  • the refrigerant distributor 42 is, as illustrated in FIG. 8 , formed by the outer tube 61 , an inner tube 62 , and a connection tube 64 .
  • the refrigerant distributor 42 has a double-tube structure.
  • the outer tube 61 is a circular tube and its axial direction is the X direction. In an upper face portion of the outer tube 61 , a plurality of flat-tube insertion holes 61 e are provided.
  • the plurality of flat-tube insertion holes 61 e are spaced from each other and arranged in the X direction.
  • the plurality of flat-tube insertion holes 61 e are through holes that pass through the upper face portion of the outer tube 61 .
  • the tube end portion 47 a of each of the flat tubes 47 is directly inserted into a flat-tube insertion hole 61 e of the outer tube 61 .
  • a closure plate 61 c is provided between the tube end portions 61 a and 61 b of the outer tube 61 , at the tube end portion 61 a , a closure plate 61 c is provided and, at the tube end portion 61 b , a closure plate 61 d is provided.
  • the tube end portion 61 a and the tube end portion 61 b are each in a closed state by the closure plate 61 c and the closure plate 61 d , respectively, and are not open.
  • connection tube 64 is, as illustrated in FIG. 8 , connected to the outer tube 61 .
  • An axial direction of the connection tube 64 is the Z direction.
  • a lower end portion 64 a of the connection tube 64 is inserted into the outer tube 61 .
  • An internal space in the connection tube 64 and a first internal space 61 g which is an internal space that faces the tube end portion 61 a of the outer tube 61 , communicate with each other.
  • a cross-sectional shape of the first internal space 61 g is circular.
  • the refrigerant distributor 42 is, as illustrated in FIG. 2 , connected to the refrigerant pipe 45 .
  • the outer tube 61 of the refrigerant distributor 42 is connected to the refrigerant pipe 45 through the connection tube 64 .
  • the refrigerant distributor 42 has a double-tube structure such that, inside the outer tube 61 , the inner tube 62 is located. Between an internal wall 61 f of the outer tube 61 and an external wall 62 f of the inner tube 62 , a gap is defined as a second internal space 61 h in the outer tube 61 .
  • a cross-sectional shape of the second internal space 61 h is doughnut-shaped, that is, ring-shaped.
  • the inner tube 62 is provided with a plurality of refrigerant outflow holes 62 c arranged in parallel to each other in a side face portion of the inner tube 62 .
  • the inner tube 62 is joined to the outer tube 61 with a partition plate 63 in between.
  • the partition plate 63 is located between the first internal space 61 g and the closure plate 61 d of the outer tube 61 .
  • the partition plate 63 partitions an area into the first internal space 61 g and the second internal space 61 h .
  • a through hole 63 a is formed in the central portion of the partition plate 63 .
  • the tube end portion 62 a is fitted into the through hole 63 a .
  • the tube end portion 62 a opens toward the first internal space 61 g .
  • the first internal space 61 g and an internal space in the inner tube 62 thus communicate with each other.
  • the tube end portion 62 b of the inner tube 62 is joined to the closure plate 61 d and is in a closed state.
  • An outer circumference portion of the partition plate 63 is joined to the internal wall 61 f of the outer tube 61 .
  • the partition plate 63 is, as described above, joined to the internal wall 61 f of the outer tube 61 and the external wall 62 f of the inner tube 62 .
  • the refrigerant that flows inside the refrigerant distributor 42 is thus allowed to pass through between the first internal space 61 g at the tube end portion 61 a to which the connection tube 64 is connected and the closure plate 61 d at the opposite tube end portion 61 b only through the internal space in the inner tube 62 .
  • the refrigerant distributor 41 and the refrigerant distributor 42 are thus each the same in configuration as the refrigerant distributor 32 illustrated in FIG. 6 and formed by the outer tubes 57 and 61 , the inner tubes 58 and 62 , the partition plates 59 and 63 , and the connection tubes 60 and 64 , respectively.
  • the refrigerant pipe 36 is connected through the connection tube 60
  • the refrigerant pipe 45 is connected through the connection tube 64 .
  • the outdoor heat exchanger 4 may be referred to as a heat exchanger.
  • the heat exchange body 43 may be referred to as a first heat exchange body.
  • the flat tube 47 may be referred to as a first flat tube.
  • the flat tube 47 connected to the refrigerant distributor 41 may be referred to as a leeward first flat tube and the flat tube 47 connected to the refrigerant distributor 42 may be referred to as a windward first flat tube.
  • the refrigerant distributor 41 may be referred to as a first refrigerant distributor and the refrigerant distributor 42 may be referred to as a second refrigerant distributor.
  • the outer tube 57 may be referred to as a first outer tube, the inner tube 58 as a first inner tube, the refrigerant outflow hole 58 c as a first refrigerant outflow hole, and the partition plate 59 as a first partition plate.
  • the outer tube 61 may be referred to as a second outer tube, the inner tube 62 as a second inner tube, the refrigerant outflow hole 62 c as a second refrigerant outflow hole, and the partition plate 63 as a second partition plate.
  • the reverse header 44 may be referred to as a first reverse header.
  • the tube end portion 47 a of the flat tube 47 that is inserted into the refrigerant distributor 41 may be referred to as one end portion of a first flat tube and the tube end portion 47 a of the flat tube 47 that is inserted into the refrigerant distributor 42 may be referred to as the other end portion of a first flat tube.
  • the outdoor heat exchanger 3 may be referred to as a second heat exchanger.
  • the heat exchange body 33 may be referred to as a second heat exchange body.
  • the flat tube 37 may be referred to as a second flat tube.
  • the flat tube 37 connected to the refrigerant distributor 31 may be referred to as a leeward second flat tube and the flat tube 37 connected to the refrigerant distributor 32 may be referred to as a windward second flat tube.
  • the refrigerant distributor 31 may be referred to as a third refrigerant distributor and the refrigerant distributor 32 may be referred to as a fourth refrigerant distributor.
  • the outer tube 51 may be referred to as a third outer tube.
  • the outer tube 53 may be referred to as a fourth outer tube, the inner tube 54 as a fourth inner tube, the refrigerant outflow hole 54 c as a fourth refrigerant outflow hole, and the partition plate 55 as a fourth partition plate.
  • the reverse header 34 may be referred to as a second reverse header.
  • the tube end portion 37 a of the flat tube 37 that is inserted into the refrigerant distributor 31 may be referred to as one end portion of a second flat tube and the tube end portion 37 a of the flat tube 37 that is inserted into the refrigerant distributor 32 may be referred to as the other end portion of a second flat tube.
  • FIG. 2 is a perspective view that illustrates a connection state in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each in a cooling operation state are connected to each other and flows of refrigerant.
  • connection tube 52 the connection tube 52 , the connection tube 56 , the connection tube 60 , and the connection tube 64 , the connection tube 56 and the connection tube 60 are connected through the refrigerant pipe 36 .
  • Refrigerant flows from the refrigerant pipe 35 connected to the connection tube 52 into the outdoor heat exchanger 3 , in which a portion of the refrigerant then condenses and the refrigerant thus transitions into a two-phase gas-liquid state, and flows out into the refrigerant pipe 36 . Subsequently, the refrigerant, which remains in a two-phase gas-liquid state, flows into the outdoor heat exchanger 4 . The refrigerant having flowed into the outdoor heat exchanger 4 is first caused to flow into the refrigerant distributor 41 .
  • the refrigerant distributor 41 has a double-tube structure such that, in its inner tube 58 , a large number of the refrigerant outflow holes 58 c are arranged in parallel to each other. Refrigerant having flowed into the refrigerant distributor 41 flows, when the refrigerant passes through inside the inner tube 58 , out through the refrigerant outflow holes 58 c into the second internal space 57 h . Subsequently, the refrigerant is distributed from the second internal space 57 h into the respective flat tubes 47 .
  • the inner tube 58 is thus provided with the refrigerant outflow holes 58 c , which enables refrigerant to be evenly distributed to the respective flat tubes 47 in the heat exchange body 43 A. Refrigerant having condensed inside the heat exchange body 43 A and the heat exchange body 43 B passes through the refrigerant distributor 42 and flows out into the refrigerant pipe 45 .
  • the refrigerant distributor 41 which is located on an inflow side of the outdoor heat exchanger 4 located downstream between the plurality of outdoor heat exchanger 3 and outdoor heat exchanger 4 that form a series refrigerant flow passage in cooling operation, has a double-tube structure.
  • the inner tube 58 in the refrigerant distributor 41 has a large number of refrigerant outflow holes 58 c arranged in parallel to each other. This configuration improves the uniformity of distribution of refrigerant in a two-phase gas-liquid state into the heat exchange body 43 A in the outdoor heat exchanger 4 located downstream.
  • refrigerant distributor 41 refrigerant flows into the first internal space 57 g in the outer tube 57 through the connection tube 60 . Subsequently, the refrigerant enters the inner tube 58 from the first internal space 57 g once and then flows out through a large number of refrigerant outflow holes 58 c arranged in parallel to each other included in the inner tube 58 into the second internal space 57 h in the outer tube 57 . At this time, in the outer tube 57 , the second internal space 57 h is separated from the first internal space 57 g by the partition plate 59 .
  • This configuration causes the refrigerant having flowed into the second internal space 57 h in the outer tube 57 does not flow toward the first internal space 57 g and flows out through the flat-tube insertion holes 57 e into the plurality of flat tubes 47 connected to the outer tube 57 .
  • FIG. 10 is a diagram that schematically illustrates distribution acts of refrigerant at the refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 11 is a diagram that schematically illustrates distribution acts of refrigerant at the refrigerant distributor 32 , 41 , 42 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 10 and FIG. 11 illustrate a case for clarity in which the refrigerant outflow holes 54 c , 58 c , 62 c open directly downward.
  • refrigerant flows in through one location, that is, the connection tube 52 , and flows out through a plurality of locations, that is, the flat-tube insertion holes 51 e .
  • This configuration tends to cause more refrigerant to flow through the flat-tube insertion hole 51 e located closer to the connection tube 52 than through the other flat-tube insertion holes 51 e.
  • refrigerant flows into the outer tube 53 , 57 , 61 through a plurality of locations, that is, the refrigerant outflow holes 54 c , 58 c , 62 c in the inner tube 54 , 58 , 62 , and flows out through a plurality of locations, that is, the flat-tube insertion holes 53 e , 57 e , 61 e .
  • This configuration improves the uniformity of distribution of refrigerant, even when outflows through the inner tube 54 , 58 , 62 are uneven, compared to a case in which no inner tube 54 , 58 , 62 is provided.
  • FIG. 12 is a diagram that schematically illustrates the state of liquid refrigerant in the refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to Embodiment 1 .
  • FIG. 13 is a diagram that schematically illustrates the state of liquid refrigerant in the refrigerant distributor 32 , 41 , 42 provided in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 12 and FIG. 13 illustrate a case for clarity in which the refrigerant outflow holes 54 c , 58 c , 62 c open directly downward.
  • FIG. 12 and FIG. 13 illustrate a case in which two-phase gas-liquid refrigerant flows into the refrigerant distributor 31 and a case in which two-phase gas-liquid refrigerant flows into the refrigerant distributor 32 , 41 , 42 .
  • refrigerant contains liquid refrigerant that accumulates at a lower portion of the outer tube 51 and the amount of refrigerant that circulates in the refrigerant circuit may decrease.
  • a case of a double-tube structure as illustrated in FIG.
  • refrigerant spouts out through a plurality of refrigerant outflow holes 54 c , 58 c , 62 c provided in the inner tube 54 , 58 , 62 .
  • This configuration disturbs liquid refrigerant that accumulates inside the outer tube 53 , 57 , 61 and thus prevents liquid refrigerant from accumulating at a lower portion of the outer tube 51 .
  • the amount of liquid refrigerant that accumulates in the outer tube 51 decreases and refrigerant is thus caused to effectively circulate in the refrigerant circuit.
  • FIG. 12 and FIG. 13 an example illustrated in FIG. 12 and FIG. 13 is provided as a case of separated flows, of which gas refrigerant and liquid refrigerant flow separately; however, flows of refrigerant are not limited to the example illustrated in FIG. 12 and FIG. 13 .
  • Other examples of flows of refrigerant that flows inside the refrigerant distributors 31 , 32 , 41 , and 42 include a case of an annular flow. In a case in which refrigerant flows as an annular flow, liquid refrigerant forms an annular shape and the annular flow of the liquid refrigerant surrounds gas refrigerant.
  • refrigerant that flows out through the refrigerant outflow holes 54 c , 58 c , and 62 c provided in the inner tubes 54 , 58 , and 62 : one case in which the refrigerant is mainly gas refrigerant and the other case in which the refrigerant is mainly liquid refrigerant.
  • gas refrigerant or liquid refrigerant mainly flows out through the refrigerant outflow holes 54 c , 58 c , 62 c varies depending on the state of the refrigerant that flows inside the inner tube 54 , 58 , 62 , as well as the arrangement and the positions of the refrigerant outflow holes 54 c , 58 c , 62 c .
  • liquid refrigerant covers the refrigerant outflow holes 54 c , 58 c , 62 c and the liquid refrigerant thus mainly flows out through the refrigerant outflow holes 54 c , 58 c , 62 c .
  • FIG. 9 is a perspective view that illustrates a connection state in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each in a heating operation state are connected to each other in the refrigeration cycle apparatus 100 according to Embodiment 1.
  • FIG. 9 illustrates a refrigerant flow passage through which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected to each other, which is expressed by simple connection of refrigerant pipes.
  • Solid arrows illustrated in FIG. 9 each represent a direction in which refrigerant flows and outlined arrows illustrated in FIG. 9 each represent a direction of wind generated by its corresponding one of the outdoor air-sending devices 9 .
  • the direction in which refrigerant flows in a heating operation state is opposite the direction in cooling operation.
  • refrigerant flows into the outdoor heat exchanger 3 and the outdoor heat exchanger 4 through the refrigerant distributor 32 and the refrigerant distributor 42 .
  • Both the refrigerant distributor 32 and the refrigerant distributor 42 are each a refrigerant distributor provided with a double-tube structure.
  • refrigerant distributor 32 refrigerant flows into the first internal space 53 g in the outer tube 53 through the connection tube 56 . Subsequently, the refrigerant enters the inner tube 54 from the first internal space 53 g once and then flows out through a large number of refrigerant outflow holes 54 c arranged in parallel to each other included in the inner tube 54 into the second internal space 53 h in the outer tube 53 . At this time, in the outer tube 53 , the second internal space 53 h is separated from the first internal space 53 g by the partition plate 55 .
  • This configuration causes the refrigerant having flowed into the second internal space 53 h in the outer tube 53 does not flow toward the first internal space 53 g and flows out through the flat-tube insertion holes 53 e into the plurality of flat tubes 37 connected to the outer tube 53 .
  • refrigerant distributor 42 refrigerant flows into the first internal space 61 g in the outer tube 61 through the connection tube 64 . Subsequently, the refrigerant enters the inner tube 62 from the first internal space 61 g once and then flows out through a large number of refrigerant outflow holes 62 c arranged in parallel to each other included in the inner tube 62 into the second internal space 61 h in the outer tube 61 . At this time, in the outer tube 61 , the second internal space 61 h is separated from the first internal space 61 g by the partition plate 63 .
  • This configuration causes the refrigerant having flowed into the second internal space 61 h in the outer tube 61 does not flow toward the first internal space 61 g and flows out through the flat-tube insertion holes 53 e into the plurality of flat tubes 47 connected to the outer tube 61 .
  • refrigerant flows out from the outdoor heat exchanger 3 and the outdoor heat exchanger 4 through the refrigerant distributor 31 and the refrigerant distributor 41 .
  • the refrigerant distributor 31 is a single-tube structured refrigerant distributor
  • the refrigerant distributor 41 is a double-tube structured refrigerant distributor. Refrigerant having flowed from the flat tubes 37 into the refrigerant distributor 31 passes through inside the outer tube 51 and flows out through the connection tube 52 .
  • refrigerant having flowed from the flat tubes 47 into the refrigerant distributor 41 first flows into the second internal space 61 h in the outer tube 57 and then subsequently flows into the inner tube 58 through the refrigerant outflow holes 58 c . Subsequently, the refrigerant passes through inside the inner tube 58 and flows out from the inner tube 58 into the first internal space 57 g , which is separated by the partition plate 59 . The refrigerant flows out from the first internal space 57 g through the connection tube 60 to the outside of the refrigerant distributor 41 .
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each serve as an evaporator.
  • the refrigerant distributor 41 which is provided on an outflow side of the outdoor heat exchanger 4 , is a refrigerant distributor structured by a double pipe such that, in its inner tube 58 , a large number of the refrigerant outflow holes 58 c are arranged in parallel to each other.
  • the double-tube structured refrigerant distributor 41 thus increases pressure loss in a refrigerant flow passage and decreases pressure on a suction side of the compressor 1 , compared to a case in which a single-tube structured refrigerant distributor is in use as the refrigerant distributor 41 . Problems thus arise in that the required amount of work of the compressor 1 is increased and the performance of the refrigeration cycle apparatus is decreased.
  • the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 included in the outdoor heat exchanger 4 should preferably be defined with consideration given to the balance between the uniformity of distribution of refrigerant in a cooling operation state and the pressure loss caused in the outdoor heat exchanger 4 in a heating operation state. That is, a part or all of the specifications of the refrigerant distributor 41 may also be designed differently from a part or all of the specifications of the refrigerant distributor 42 such as the uniformity of refrigerant in a cooling operation state is ensured and pressure loss in a heating operation state is controllable.
  • the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 should preferably be defined to be suited according to data such as results from simulations or experiments with prototypes. Specifically, by increasing the diameters and the numbers of the refrigerant outflow holes 58 c and the refrigerant outflow holes 62 c , increase in pressure loss is reduced and the distribution characteristics of refrigerant are modified. According to the modified characteristics, the spacings or the locations of the refrigerant outflow holes 58 c and the refrigerant outflow holes 62 c are modified such that reduction in the uniformity of distribution in cooling operation is prevented.
  • the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 thus should preferably be adjusted to achieve the balance between the uniformity of distribution of refrigerant in a cooling operation state and the pressure loss in a heating operation state, with consideration given to this balance.
  • the specifications of the refrigerant distributor 41 and the specifications of the refrigerant distributor 42 are thus defined according to the uniformity state of distribution of refrigerant when the outdoor heat exchangers 3 and 4 serve as condensers and the pressure loss caused when the outdoor heat exchangers 3 and 4 serve as evaporators.
  • a part or all of the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 may also be designed differently from a part or all of the specifications of the refrigerant distributor 32 included in the outdoor heat exchanger 3 .
  • the specifications described above of the refrigerant distributor 41 and the refrigerant distributor 42 may also be modified such that total pressure loss of the refrigerant distributor 41 and the refrigerant distributor 42 is smaller than pressure loss of the refrigerant distributor 32 included in the outdoor heat exchanger 3 .
  • the plurality of outdoor heat exchanger 3 and outdoor heat exchanger 4 that form a series refrigerant flow passage in heating operation each serve as an evaporator.
  • the refrigerant distributor 42 which is located on an inflow side of the outdoor heat exchanger 4 located upstream
  • the refrigerant distributor 32 which is located on an inflow side of the outdoor heat exchanger 3 located downstream, thus each have a double-tube structure.
  • the inner tube 62 in the refrigerant distributor 42 and the inner tube 54 in the refrigerant distributor 32 respectively have a large number of refrigerant outflow holes 62 c arranged in parallel to each other and a large number of refrigerant outflow holes 54 c arranged in parallel to each other.
  • This configuration improves the uniformity of distribution of refrigerant in the outdoor heat exchanger 4 located upstream and the outdoor heat exchanger 3 located downstream, in which refrigerant in a two-phase gas-liquid state is evenly distributed to the heat exchange body 43 B and the heat exchange body 33 B.
  • Cases are described above in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 form a series refrigerant flow passage in both cooling operation and heating operation.
  • the configuration is, however, not limited to such cases.
  • a circuit may also be formed such that the two outdoor heat exchangers 3 and 4 are configured to switch between a series refrigerant flow passage and a parallel refrigerant flow passage: forming a series refrigerant flow passage in cooling operation and forming a parallel refrigerant flow passage in heating operation.
  • FIG. 14 is a refrigerant circuit diagram that illustrates a configuration of a refrigeration cycle apparatus 100 according to Modification 1 of Embodiment 1.
  • FIG. 14 illustrates flows of refrigerant in a case in which the refrigeration cycle apparatus 100 according to Modification 1 is in a cooling operation state.
  • FIG. 15 is a refrigerant circuit diagram that illustrates a configuration of the refrigeration cycle apparatus 100 according to Modification 1 of Embodiment 1.
  • FIG. 15 illustrates flows of refrigerant in a case in which the refrigeration cycle apparatus 100 according to Modification 1 is in a heating operation state.
  • Modification 1 when the refrigeration cycle apparatus 100 is in a heating operation state, as illustrated in FIG. 15 , a parallel refrigerant flow passage is formed in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in parallel to each other.
  • the controller 11 exercises control such that the expansion valve 5 and the expansion valve 6 are each in an open state, the solenoid valve 7 is in a closed state, and the solenoid valve 8 is in an open state.
  • the compressor 1 sucks in refrigerant from the accumulator 10 and then compresses the refrigerant.
  • the compressed refrigerant turns into gas refrigerant, is then discharged from the compressor 1 , flows through the four-way valve 2 and the refrigerant pipe 305 out from the outdoor unit 101 , and flows into the indoor unit 201 .
  • the refrigerant condenses in the indoor heat exchanger 21 and supplies heating energy to air.
  • the refrigerant then flows out from the indoor unit 201 and then flows into the outdoor unit 101 .
  • the refrigerant branches off into the refrigerant pipe 302 and the refrigerant pipe 304 and the respective branches of the refrigerant flow into the expansion valve 5 and the expansion valve 6 .
  • Each refrigerant reduced in pressure and expanded by the expansion valve 5 and the expansion valve 6 flows into and evaporates in its corresponding one of the outdoor heat exchanger 3 and the outdoor heat exchanger 4 .
  • the refrigerant having flowed out from the outdoor heat exchanger 4 passes through the solenoid valve 8 and then merges with refrigerant having flowed out from the outdoor heat exchanger 3 .
  • the refrigerant having merged flows through the four-way valve 2 and the refrigerant pipe 306 into the accumulator 10 .
  • the refrigerant is sucked from the accumulator 10 into the compressor 1 again and circulates in the refrigerant circuit. This operation establishes a refrigerant circuit that has a refrigerant flow passage through which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in parallel to each other.
  • the opening degree of one of the expansion valve 5 and the expansion valve 6 through which more refrigerant easily flows is reduced, while the opening degree of the other of the expansion valve 5 and the expansion valve 6 through which refrigerant less easily flows is increased.
  • Embodiment 1 a case is described in Embodiment 1 in which the number of outdoor heat exchangers is two. However, even when the number of outdoor heat exchangers is three or more, the configuration of Embodiment 1 may also be applied. Specifically, in a case in which the number of n outdoor heat exchangers are configured to form a series refrigerant flow passage in accordance with control by the refrigerant circuit and serve as condensers, the same configuration of the outdoor heat exchanger 3 is used for an outdoor heat exchanger located upstream while the same configuration of the outdoor heat exchanger 4 is used for an outdoor heat exchanger located downstream. This configuration naturally results in an advantageous effect similar to that of Embodiment 1.
  • FIG. 16 is a refrigerant circuit diagram that illustrates a configuration of a refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1.
  • FIG. 17 is a diagram that illustrates flows of refrigerant in a case in which the refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1 is in a cooling operation state.
  • FIG. 18 illustrates flows of refrigerant in a case in which the refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1 is in a heating operation state.
  • the configuration illustrated in FIG. 16 and the configuration illustrated in FIG. 1 differ from each other in that, instead of the outdoor heat exchanger 3 illustrated in FIG. 1 , two outdoor heat exchangers 3 A and 3 B are provided in FIG. 16 .
  • the two outdoor heat exchangers 3 A and 3 B are connected in parallel to each other.
  • the outdoor heat exchangers 3 A and 3 B each have the same configuration of the outdoor heat exchanger 3 illustrated in FIG. 1 .
  • the other configurations are the same as those illustrated in FIG. 1 and their descriptions are thus omitted here.
  • the outdoor heat exchangers 3 A and 3 B serve as outdoor heat exchangers located upstream and the outdoor heat exchanger 4 serve as an outdoor heat exchanger located downstream.
  • the refrigerant distributors 31 of the outdoor heat exchangers 3 A and 3 B each have a single-tube structure and the refrigerant distributors 32 of the outdoor heat exchangers 3 A and 3 B each have a double-tube structure.
  • gas refrigerant discharged from the compressor 1 flows into the refrigerant distributors 31 of the outdoor heat exchangers 3 A and 3 B.
  • the gas refrigerant exchanges heat with air at the outdoor heat exchangers 3 A and 3 B, a portion of the gas refrigerant condenses, and the gas refrigerant thus transitions into a two-phase gas-liquid state.
  • the two-phase gas-liquid refrigerant having flowed out from the outdoor heat exchanger 3 A and the two-phase gas-liquid refrigerant having flowed out from the outdoor heat exchanger 3 B merges with each other on an upstream side of the solenoid valve 7 .
  • the refrigerant having merged is caused to flow through the solenoid valve 7 into the refrigerant distributor 41 of the outdoor heat exchanger 4 .
  • the refrigerant distributor 41 has a double-tube structure such that, in its inner tube 58 , a large number of the refrigerant outflow holes 58 c are arranged in parallel to each other. Refrigerant having flowed into the refrigerant distributor 41 flows, when the refrigerant passes through inside the inner tube 58 , out through the refrigerant outflow holes 58 c into the second internal space 57 h .
  • the inner tube 58 is thus provided with the refrigerant outflow holes 58 c , which enables refrigerant to be evenly distributed to the respective flat tubes 47 in the heat exchange body 43 A.
  • Refrigerant having condensed inside the heat exchange body 43 A and the heat exchange body 43 B passes through the refrigerant distributor 42 and flows out into the refrigerant pipe 45 .
  • the refrigerant having flowed out from the outdoor heat exchanger 4 flows into the indoor heat exchanger 21 .
  • the refrigerant exchanges heat with air and thus evaporates. Subsequently, the refrigerant flows out from the indoor unit 201 and then flows into the outdoor unit 101 .
  • the refrigerant flows through the four-way valve 2 and the refrigerant pipe 306 into the accumulator 10 .
  • the refrigerant is sucked from the accumulator 10 into the compressor 1 again and circulates in the refrigerant circuit.
  • the refrigerant distributor 41 which is located on an inflow side of the outdoor heat exchanger 4 located downstream between the plurality of outdoor heat exchangers 3 A and 3 B and the outdoor heat exchanger 4 that form a series refrigerant flow passage in cooling operation, has a double-tube structure.
  • the inner tube 58 in the refrigerant distributor 41 has a large number of refrigerant outflow holes 58 c arranged in parallel to each other. This configuration improves the uniformity of distribution of refrigerant in a two-phase gas-liquid state into the heat exchange body 43 A in the outdoor heat exchanger 4 located downstream.
  • the compressed refrigerant turns into gas refrigerant, is then discharged from the compressor 1 , flows through the four-way valve 2 and the refrigerant pipe 305 out from the outdoor unit 101 , and flows into the indoor unit 201 .
  • the refrigerant condenses in the indoor heat exchanger 21 and supplies heating energy to air.
  • the refrigerant then flows out from the indoor unit 201 and then flows into the outdoor unit 101 .
  • the refrigerant branches off into the refrigerant pipe 302 and the refrigerant pipe 304 and the respective branches of the refrigerant flow into the expansion valve 5 and the expansion valve 6 .
  • Each refrigerant reduced in pressure and expanded by the expansion valve 5 and the expansion valve 6 flows into and evaporates in its corresponding one of the outdoor heat exchangers 3 A and 3 B and the outdoor heat exchanger 4 .
  • the refrigerant having flowed out from the outdoor heat exchanger 4 passes through the solenoid valve 8 and then merges with refrigerant having flowed out from the outdoor heat exchangers 3 A and 3 B. Subsequently, the refrigerant having merged flows through the four-way valve 2 and the refrigerant pipe 306 into the accumulator 10 .
  • the refrigerant is sucked from the accumulator 10 into the compressor 1 again and circulates in the refrigerant circuit. This operation establishes a refrigerant circuit that has a refrigerant flow passage through which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in parallel to each other.
  • a series refrigerant flow passage may also be formed in which the outdoor heat exchangers 3 A and 3 B and the outdoor heat exchanger 4 are connected in series to each other.
  • the flows of refrigerant in this case are opposite to the flows of refrigerant in a cooling operation state described above with reference to FIG. 17 . Their descriptions are thus omitted here.
  • refrigerant in a two-phase gas-liquid state in which gas refrigerant and liquid refrigerant is mixed to each other may flow into an outdoor heat exchanger located downstream.
  • the refrigeration cycle apparatus 100 is configured to form a refrigerant flow passage such that, in cooling operation, the outdoor heat exchanger 4 is located downstream and the outdoor heat exchanger 3 is located upstream.
  • the refrigerant distributor 41 of the outdoor heat exchanger 4 located downstream has a double-tube structure such that, in its inner tube 58 , the plurality of refrigerant outflow holes 58 c are formed.
  • the function of the refrigerant distributor 41 prevents a situation in which refrigerant is unevenly distributed to the plurality of flat tubes 47 in the outdoor heat exchanger 4 .
  • Refrigerant is thus evenly distributed to the plurality of flat tubes 47 , which ensures that the required heat exchange amount is uniform across all faces of the heat exchange body 43 included in the outdoor heat exchanger 4 and that a reduction in heat exchange efficiency is thus prevented.
  • the outdoor heat exchanger 4 has the refrigerant distributor 41 and the refrigerant distributor 42 .
  • the refrigerant distributors 41 and 42 each have a double-tube structure formed by an outer tube and an inner tube. Also, in the inner tubes 58 and 62 , the respective refrigerant outflow holes 58 c and 62 c are formed, through which refrigerant flows from the inner tubes out into the inside of the outer tubes.
  • the flat tubes 47 are inserted into the outer tubes 57 and 61 . Also in a case in which two-phase gas-liquid refrigerant is caused to flow into the refrigerant distributor 41 or 42 , the refrigerant is thus evenly distributed to all the flat tubes 47 .
  • the refrigerant distributor 31 provided in the outdoor heat exchanger 3 is a single-tube structured and is thus designed to reduce pressure loss in cooling operation and heating operation.
  • FIG. 19 is a perspective view that illustrates a connection state in which an outdoor heat exchanger 3 C and an outdoor heat exchanger 4 C are connected to each other in a refrigeration cycle apparatus 100 according to Embodiment 2.
  • the configuration of the refrigeration cycle apparatus 100 according to Embodiment 2 is basically the same as the configuration of the refrigeration cycle apparatus 100 according to Embodiment 1.
  • Embodiment 2 differs from Embodiment 1 in that, instead of the outdoor heat exchangers 3 and 4 in Embodiment 1, the respective outdoor heat exchangers 3 C and 4 C are provided in Embodiment 2.
  • the other configurations are the same as those in Embodiment 1 and their descriptions are thus omitted here.
  • the heat exchange bodies 33 included in the outdoor heat exchanger 3 and the heat exchange bodies 43 included in the outdoor heat exchanger 4 are each located as two layers in a direction along a direction of wind generated by their corresponding one of the outdoor air-sending devices 9 .
  • a heat exchange body 33 included in the outdoor heat exchanger 3 C and a heat exchange body 43 included in the outdoor heat exchanger 4 C are each located as a single layer in a direction along a direction of wind generated by its corresponding one of the outdoor air-sending devices 9 .
  • FIG. 19 illustrates a refrigerant flow passage through which the outdoor heat exchanger 3 C and the outdoor heat exchanger 4 C are connected in series to each other, which is expressed by simple connection of refrigerant pipes.
  • Outlined arrows each represent a direction of wind generated by its corresponding one of the outdoor air-sending devices 9 .
  • arrows illustrated around a refrigerant pipe 35 A, a refrigerant pipe 36 A, and a refrigerant pipe 45 A represent flows of refrigerant.
  • Solid arrows represent flows of refrigerant in cooling operation and dashed arrows represent flows of refrigerant in heating operation.
  • the outdoor heat exchanger 3 C is formed by a refrigerant distributor 31 , a refrigerant distributor 32 , and the heat exchange body 33 .
  • the heat exchange body 33 is formed by a plurality of flat tubes 37 and a plurality of fins 38 .
  • the configuration of the heat exchange body 33 is as described in Embodiment 1 and its description is thus omitted here.
  • the refrigerant distributor 31 which is single-tube structured, is provided on top of the heat exchange body 33 and the refrigerant distributor 32 , which is double-tube structured, is provided under the heat exchange body 33 .
  • the refrigerant pipe 35 A is connected to the refrigerant distributor 31 through a connection tube 52 and the refrigerant pipe 36 A is connected to the refrigerant distributor 32 through a connection tube 56 .
  • the outdoor heat exchanger 4 C is formed by a refrigerant distributor 41 , a refrigerant distributor 42 , and the heat exchange body 43 .
  • the heat exchange body 43 is formed by a plurality of flat tubes 47 and a plurality of fins 48 .
  • the configuration of the heat exchange body 43 is as described in Embodiment 1 and its description is thus omitted here.
  • the refrigerant distributor 41 which is double-tube structured, is provided on top of the heat exchange body 43 and the refrigerant distributor 42 , which is double-tube structured, is provided under the heat exchange body 43 .
  • the refrigerant pipe 36 A is connected to the refrigerant distributor 41 through a connection tube 60 and the refrigerant pipe 45 A is connected to the refrigerant distributor 42 through a connection tube 64 .
  • the outdoor heat exchanger 4 C may be referred to as a heat exchanger.
  • the heat exchange body 43 may be referred to as a first heat exchange body.
  • the flat tube 47 may be referred to as a first flat tube.
  • the refrigerant distributor 41 may be referred to as a first refrigerant distributor and the refrigerant distributor 42 may be referred to as a second refrigerant distributor.
  • an outer tube 57 may be referred to as a first outer tube, an inner tube 58 as a first inner tube, and a partition plate 59 as a first partition plate.
  • an outer tube 61 may be referred to as a second outer tube, an inner tube 62 as a second inner tube, and a partition plate 63 as a second partition plate.
  • a tube end portion 47 c of the flat tube 47 which is inserted into the refrigerant distributor 41 , may be referred to as one end portion of a first flat tube and a tube end portion 47 d of the flat tube 47 , which is inserted into the refrigerant distributor 42 , may be referred to as the other end portion of a first flat tube.
  • the outdoor heat exchanger 3 C may be referred to as a second heat exchanger.
  • the heat exchange body 33 may be referred to as a second heat exchange body.
  • the flat tube 37 may be referred to as a second flat tube.
  • the refrigerant distributor 31 may be referred to as a third refrigerant distributor and the refrigerant distributor 32 may be referred to as a fourth refrigerant distributor.
  • an outer tube 51 may be referred to as a third outer tube.
  • An outer tube 53 may be referred to as a fourth outer tube, an inner tube 54 as a fourth inner tube, and a partition plate 55 as a fourth partition plate.
  • a tube end portion 37 c of the flat tube 37 which is inserted into the refrigerant distributor 31 , may be referred to as one end portion of a second flat tube and a tube end portion 37 d of the flat tube 37 , which is inserted into the refrigerant distributor 32 , may be referred to as the other end portion of a second flat tube.
  • gas refrigerant discharged from the compressor 1 which is referable to FIG. 1 , flows from the refrigerant pipe 35 A through the connection tube 52 into the refrigerant distributor 31 .
  • a portion of the refrigerant having flowed in condenses in the outdoor heat exchanger 3 C and the refrigerant thus transitions into a two-phase gas-liquid state and flows out through the refrigerant distributor 32 into the refrigerant pipe 36 A.
  • the refrigerant which remains in a two-phase gas-liquid state, flows into the outdoor heat exchanger 4 C.
  • the refrigerant having flowed into the outdoor heat exchanger 4 C is first caused to flow through the connection tube 60 into the refrigerant distributor 41 .
  • the refrigerant distributor 41 has a double-tube structure such that, in its inner tube 58 , a large number of the refrigerant outflow holes 58 c are arranged in parallel to each other. Refrigerant having flowed into the refrigerant distributor 41 flows, when the refrigerant passes through inside the inner tube 58 , out through the refrigerant outflow holes 58 c into the second internal space 57 h in the outer tube 57 .
  • the inner tube 58 is thus provided with the refrigerant outflow holes 58 c , which enables refrigerant to be evenly distributed to the respective flat tubes 47 in the heat exchange body 43 .
  • Refrigerant having condensed inside the heat exchange body 43 flows out from the refrigerant distributor 42 through the connection tube 64 into the refrigerant pipe 45 A.
  • the refrigerant distributor 41 which is located on an inflow side of the outdoor heat exchanger 4 C located downstream between the plurality of outdoor heat exchanger 3 C and outdoor heat exchanger 4 C that form a series refrigerant flow passage in cooling operation, has a double-tube structure.
  • the inner tube 58 in the refrigerant distributor 41 has a large number of refrigerant outflow holes 58 c arranged in parallel to each other. This configuration improves the uniformity of distribution of refrigerant in a two-phase gas-liquid state into the heat exchange body 43 in the outdoor heat exchanger 4 C located downstream.
  • refrigerant flows in a heating operation state are described below. As seen in comparison of the solid arrows and the dashed arrows illustrated in FIG. 19 , the direction in which refrigerant flows in a heating operation state is opposite the direction in a cooling operation state. In a heating operation state, refrigerant flows into the outdoor heat exchanger 3 C and the outdoor heat exchanger 4 C through the refrigerant distributor 32 and the refrigerant distributor 42 . Both the refrigerant distributor 32 and the refrigerant distributor 42 are each a refrigerant distributor provided with a double-tube structure.
  • the plurality of outdoor heat exchanger 3 C and outdoor heat exchanger 4 C that form a series refrigerant flow passage in a heating operation state each serve as an evaporator.
  • the refrigerant distributor 42 which is located on an inflow side of the outdoor heat exchanger 4 C located upstream, and the refrigerant distributor 32 , which is located on an inflow side of the outdoor heat exchanger 3 C located downstream, thus each have a double-tube structure.
  • the inner tube 62 in the refrigerant distributor 42 and the inner tube 54 in the refrigerant distributor 32 respectively have a large number of refrigerant outflow holes 62 c arranged in parallel to each other and a large number of refrigerant outflow holes 54 c arranged in parallel to each other.
  • This configuration improves the uniformity of distribution of refrigerant in the outdoor heat exchanger 4 C located upstream and the outdoor heat exchanger 3 C located downstream, in which refrigerant in a two-phase gas-liquid state is evenly distributed to the heat exchange body 43 and the heat exchange body 33 .
  • the refrigerant distributor 41 of the outdoor heat exchanger 4 C which is located downstream in a cooling operation state, is double-tube structured, the same advantageous effects are obtained as in Embodiment 1 described above.
  • FIG. 20 is a perspective view that illustrates an external view of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to Embodiment 3.
  • FIG. 21 includes plan views that schematically illustrate examples of a configuration of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to Embodiment 3.
  • the outdoor unit 101 has outdoor heat exchangers 3 and 4 , refrigerant pipes 35 , 36 , and 45 , which are referable to FIG. 2 and through which the outdoor heat exchangers 3 and 4 are connected to each other, a housing 101 a , and an outdoor air-sending device 9 .
  • the housing 101 a has, as illustrated in FIG. 20 , a box shape. Inside the housing 101 a , as illustrated in FIG. 21 , the outdoor heat exchangers 3 and 4 are housed. In addition, illustration is omitted in FIG. 21 ; inside the housing 101 a , other components are further housed such as the compressor 1 , the four-way valve 2 , the expansion valves 5 and 6 , the solenoid valves 7 and 8 , which are illustrated in FIG. 1 , and an unillustrated control box, which houses a control board that forms the controller 11 . Also, in an upper portion 101 b of the housing 101 a , the outdoor air-sending device 9 is located.
  • the outdoor air-sending device 9 is driven to rotate and flows of air are thus generated as represented by the outlined arrows illustrated in FIG. 20 .
  • the air is sucked from at least two side faces among four side faces of the housing 101 a into the housing 101 a . Also, the air passes through the outdoor heat exchangers 3 and 4 and is then discharged upward from an air outlet provided to the upper portion 101 b of the housing 101 a.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each have a rectangular shape in plan view.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located such that they face each other.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are each located along a part of side faces of the housing 101 a . That is, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located along respective two side faces among the four side faces of the housing 101 a.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each have an L-shape in plan view.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located in positions that are point-symmetric with each other.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located along all the side faces of the housing 101 a . That is, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located along the four side faces of the housing 101 a.
  • FIG. 21 ( c ) a case is illustrated in which three outdoor heat exchangers are provided, as in Modification 2 of Embodiment 1 illustrated in FIG. 16 to FIG. 18 .
  • the outdoor heat exchangers 3 A, 3 B, and 4 are located in a U-shape in plan view.
  • the outdoor heat exchangers 3 A, 3 B, and 4 are located along a part of the side faces of the housing 101 a . That is, the outdoor heat exchangers 3 A, 3 B, and 4 are located along three side faces of the housing 101 a.
  • FIG. 22 is a perspective view that illustrates an external view of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to Modification of Embodiment 3.
  • FIG. 23 is a plan view that schematically illustrates an example of a configuration of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to Modification of Embodiment 3.
  • one outdoor air-sending device 9 is located in the upper portion 101 b of the housing 101 a .
  • This number is, however, not limited to such a case.
  • the number of outdoor air-sending devices 9 may also be one as illustrated in FIG. 20 or two as illustrated in FIG. 1 , which is referred to in Embodiment 1.
  • FIG. 22 illustrates a case in which two outdoor air-sending devices 9 are provided in an upper portion 101 b of a housing 101 a.
  • an outdoor heat exchanger 3 and an outdoor heat exchanger 4 each have an L-shape in plan view.
  • the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located in positions that are line-symmetric with each other. Also, in the example illustrated in FIG. 23 , the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are located along three side faces among four side faces of the housing 101 a.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Other Air-Conditioning Systems (AREA)
US18/880,197 2022-08-22 2022-08-22 Heat exchanger and refrigeration cycle apparatus Pending US20250389432A1 (en)

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PCT/JP2022/031523 WO2024042575A1 (ja) 2022-08-22 2022-08-22 熱交換器および冷凍サイクル装置

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JP2012102992A (ja) 2010-11-11 2012-05-31 Atsuo Morikawa 室外機のパラレルフロー多段凝縮過冷却器
KR101372096B1 (ko) * 2011-11-18 2014-03-07 엘지전자 주식회사 열교환기
JP6827542B2 (ja) 2017-07-04 2021-02-10 三菱電機株式会社 冷凍サイクル装置
EP4279850A3 (en) * 2018-06-11 2024-03-06 Mitsubishi Electric Corporation Outdoor unit of air-conditioning apparatus and air-conditioning apparatus
JP6664558B1 (ja) * 2019-02-04 2020-03-13 三菱電機株式会社 熱交換器、熱交換器を備えた空気調和装置、および熱交換器を備えた冷媒回路
WO2021234959A1 (ja) * 2020-05-22 2021-11-25 三菱電機株式会社 冷媒分配器、熱交換器及び空気調和装置

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WO2024042575A1 (ja) 2024-02-29

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