EP4779247A1 - Heat exchanger unit, air conditioning indoor equipment, and refrigeration cycle device - Google Patents

Heat exchanger unit, air conditioning indoor equipment, and refrigeration cycle device

Info

Publication number
EP4779247A1
EP4779247A1 EP25817402.8A EP25817402A EP4779247A1 EP 4779247 A1 EP4779247 A1 EP 4779247A1 EP 25817402 A EP25817402 A EP 25817402A EP 4779247 A1 EP4779247 A1 EP 4779247A1
Authority
EP
European Patent Office
Prior art keywords
heat transfer
transfer tube
long side
flow path
heat exchanger
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
EP25817402.8A
Other languages
German (de)
French (fr)
Inventor
Shota AGO
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.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
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 Daikin Industries Ltd filed Critical Daikin Industries Ltd
Publication of EP4779247A1 publication Critical patent/EP4779247A1/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • F28D1/0535—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 the conduits having a non-circular cross-section
    • F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
    • F28D1/05391—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
    • 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
    • F24F1/0007—Indoor units, e.g. fan coil units
    • F24F1/0059—Indoor units, e.g. fan coil units characterised by heat exchangers
    • F24F1/0063—Indoor units, e.g. fan coil units characterised by heat exchangers by the mounting or arrangement of the heat exchangers
    • 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
    • F25B39/02—Evaporators
    • 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
    • F28D1/03—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 plate-like or laminated conduits
    • F28D1/0308—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 plate-like or laminated conduits the conduits being formed by paired plates touching each other
    • F28D1/0325—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 plate-like or laminated conduits the conduits being formed by paired plates touching each other the plates having lateral openings therein for circulation of the heat-exchange medium from one conduit to another
    • F28D1/0333—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 plate-like or laminated conduits the conduits being formed by paired plates touching each other the plates having lateral openings therein for circulation of the heat-exchange medium from one conduit to another the plates having integrated connecting members
    • F28D1/0341—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 plate-like or laminated conduits the conduits being formed by paired plates touching each other the plates having lateral openings therein for circulation of the heat-exchange medium from one conduit to another the plates having integrated connecting members with U-flow or serpentine-flow inside the conduits
    • 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
    • F28D1/0417—Multi-circuit heat exchangers, e.g. integrating different heat exchange sections in the same unit or heat exchangers for more than two fluids with particular circuits for the same heat exchange medium, e.g. with the heat exchange medium flowing through sections having different heat exchange capacities or for heating/cooling the heat exchange medium at different temperatures
    • 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
    • F28D1/0435—Combination of units extending one behind 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
    • F28D1/047—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 bent, e.g. in a serpentine or zig-zag
    • F28D1/0471—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 bent, e.g. in a serpentine or zig-zag the conduits having a non-circular cross-section
    • 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
    • F28D1/047—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 bent, e.g. in a serpentine or zig-zag
    • F28D1/0475—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 bent, e.g. in a serpentine or zig-zag the conduits having a single U-bend
    • F28D1/0476—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 bent, e.g. in a serpentine or zig-zag the conduits having a single U-bend the conduits having a non-circular cross-section
    • 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
    • F28D1/047—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 bent, e.g. in a serpentine or zig-zag
    • F28D1/0477—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 bent, e.g. in a serpentine or zig-zag the conduits being bent in a serpentine or zig-zag
    • 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
    • F28D1/047—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 bent, e.g. in a serpentine or zig-zag
    • F28D1/0477—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 bent, e.g. in a serpentine or zig-zag the conduits being bent in a serpentine or zig-zag
    • F28D1/0478—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 bent, e.g. in a serpentine or zig-zag the conduits being bent in a serpentine or zig-zag the conduits having a non-circular cross-section
    • 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
    • F28D1/0535—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 the conduits having a non-circular cross-section
    • F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
    • 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
    • F28D1/0535—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 the conduits having a non-circular cross-section
    • F28D1/05366—Assemblies of conduits connected to common headers, e.g. core type radiators
    • F28D1/05383—Assemblies of conduits connected to common headers, e.g. core type radiators with multiple rows of conduits or with multi-channel conduits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/02—Tubular elements of cross-section which is non-circular
    • F28F1/025—Tubular elements of cross-section which is non-circular with variable shape, e.g. with modified tube ends, with different geometrical features
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/126—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element consisting of zig-zag shaped fins
    • F28F1/128—Fins with openings, e.g. louvered fins
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/14—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally
    • F28F1/22—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means having portions engaging further tubular elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/24—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
    • F28F1/32—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/24—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely
    • F28F1/32—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending transversely the means having portions engaging further tubular elements
    • F28F1/325—Fins with openings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element
    • 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
    • F28F9/0219—Arrangements for sealing end plates into casing or header box; Header box sub-elements
    • F28F9/0221—Header boxes or end plates formed by stacked elements
    • 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
    • F28F9/0275—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 branch 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
    • F28F9/0278—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 stacked distribution plates or perforated plates arranged over end plates
    • 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
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0234—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in series arrangements
    • 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
    • F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
    • 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
    • F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
    • F28D2021/007—Condensers
    • 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
    • F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
    • F28D2021/0071—Evaporators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/02—Tubular elements of cross-section which is non-circular
    • F28F1/022—Tubular elements of cross-section which is non-circular with multiple channels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F2215/00—Fins
    • F28F2215/12—Fins with U-shaped slots for laterally inserting conduits
    • 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
    • F28F9/0219—Arrangements for sealing end plates into casing or header box; Header box sub-elements
    • F28F9/0224—Header boxes formed by sealing end plates into covers

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Abstract

A heat exchanger unit (40) includes a plate structure (62) in which a connection flow path (75) is formed. The connection flow path (75) has a first portion (80), a second portion (85), and a third portion (90). The first portion (80) communicates with all inner flow paths (50a) of a first heat transfer tube (51). The second portion (85) communicates with all inner flow paths (50a) of a second heat transfer tube (52). One end of the third portion (90) is connected to a first long side (81a), one of the long sides of the first portion (80). The other end of the third portion (90) is connected to a second long side (86b), one of the long sides of the second portion (85).

Description

    TECHNICAL FIELD
  • The present disclosure relates to a heat exchanger unit, an air-conditioning indoor unit, and a refrigeration cycle apparatus.
    • BACKGROUND ART
  • Patent Document 1 discloses a heat exchanger that includes a plurality of heat transfer tubes. The heat transfer tube of the heat exchanger is a flat tube of which the cross section is shaped into an elongated circle. The heat exchanger has two tube rows. In this heat exchanger, the two tube rows are arranged in the front-back direction. Each of the tube rows is comprised of a plurality of heat transfer tubes. In each of the tube rows, the plurality of heat transfer tubes are arranged in a line as well as being spaced apart from each other at regular intervals in the upper-lower direction.
  • In each of the tube rows, end portions of the heat transfer tubes are connected with a header. The header is comprised of a plurality of plate members that are stacked. In the header, a connection flow path that connects a first heat transfer tube forming the front tube row and a second heat transfer tube forming the rear tube row is formed. The connection flow path is formed to connect the short side of an end surface of the first heat transfer tube and the short side of an end surface of the second heat transfer tube. A refrigerant flowing in the heat exchanger passes through the connection flow path in the header and then flows from one of the first heat transfer tube and the second heat transfer tube to the other.
    • CITATION LIST PATENT DOCUMENT
  • Patent Document 1: WO 2021/130834
    • SUMMARY OF THE INVENTION TECHNICAL PROBLEM
  • A plurality of inner flow paths may be formed in a flat tube used as a heat transfer tube. Each of the inner flow paths is formed from one end of the flat tube to the other. The plurality of inner flow paths are arranged in the width direction of the flat tube (the longitudinal direction of the cross section of the flat tube).
  • As described above, in the heat exchanger of Patent Document 1, the connection flow path in the header connects the short side of the end surface of the first heat transfer tube forming the front tube row and the short side of the end surface of the second heat transfer tube forming the rear tube row. Thus, if the flat tube in which the plurality of inner flow paths are formed is used as the heat transfer tube of the heat exchanger of Patent Document 1, a larger amount of refrigerant can flow into each of the inner flow paths of the flat tube that is close to the connection flow path, and a smaller amount of refrigerant can flow into each of the inner flow paths of the flat tube that is distant from the connection flow path. If the flow rate of refrigerant is not uniform among the plurality of inner flow paths of the flat tube, the heat exchanger cannot produce sufficient performance.
  • An object of the present disclosure is to improve the performance of a heat exchanger that includes a flat tube in which a plurality of inner flow paths are formed.
    • SOLUTION TO THE PROBLEM
  • A first aspect of the present disclosure is directed to a heat exchanger unit (40) comprising a plurality of fins (53) and a plurality of heat transfer tubes (50) and configured to exchange heat between a heat medium flowing in the heat transfer tubes (50) and air.
  • In the first aspect, each of the plurality of heat transfer tubes (50) is a flat tube in which a plurality of inner flow paths (50a) are formed; in each of the plurality of heat transfer tubes (50), the plurality of inner flow path (50a) are arranged in a line in a width direction of the heat transfer tube (50); the plurality of heat transfer tubes (50) include a plurality of first heat transfer tubes (51) and a plurality of second heat transfer tubes (52); the plurality of first heat transfer tubes (51) arranged in a line as well as being spaced apart from each other at intervals form a first tube row (56), and the plurality of second heat transfer tubes (52) arranged in a line as well as being spaced apart from each other at intervals form a second tube row (57); and the first tube row (56) and the second tube row (57) are disposed in sequence from an upstream side to a downstream side of a flow of air that passes through the heat exchanger unit (40).
  • In the first aspect, the heat exchanger unit (40) includes a plate structure (62) which is joined to end portions of the plurality of heat transfer tubes (50) and in which a connection flow path (75) connecting one of the first heat transfer tubes (51) and one of the second heat transfer tubes (52) is formed, the connection flow path (75) has a first portion (80) facing an end surface of the first heat transfer tube (51) and communicating with all the inner flow paths (50a) formed in the first heat transfer tube (51), a second portion (85) facing an end surface of the second heat transfer tube (52) and communicating with all the inner flow paths (50a) formed in the second heat transfer tube (52), and a third portion (90) communicating with both the first portion (80) and the second portion (85).
  • In the first aspect, the first portion (80) has a pair of first long sides (81a, 81b) extending along a width direction of the first heat transfer tube (51), the second portion (85) has a pair of second long sides (86a, 86b) extending along a width direction of the second heat transfer tube (52), one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80), and the other end of the third portion (90) is connected to only one of the pair of second long sides (86a, 86b) of the second portion (85).
  • In the heat exchanger unit (40) of the first aspect, when the heat medium flows in the connection flow path (75) from the first heat transfer tube (51) to the second heat transfer tube (52), the heat medium flowing in the third portion (90) flows into the second portion (85) from the second long sides (86a, 86b) extending along the width direction of the second heat transfer tube (52), and then is distributed to all the plurality of inner flow paths (50a) arranged in the width direction of the second heat transfer tube (52). When the heat medium flows in the connection flow path (75) from the second heat transfer tube (52) to the first heat transfer tube (51), the heat medium flowing in the third portion (90) flows into the first portion (80) from the first long sides (81a, 81b) extending along the width direction of the first heat transfer tube (51), and then is distributed to all the plurality of inner flow paths (50a) arranged in the width direction of the first heat transfer tube (51).
  • Accordingly, in the first aspect, the heat medium flowing in the connection flow path (75) is distributed to all the inner flow paths (50a) formed in the heat transfer tube (50), and thus there is only small difference in the flow rate of the heat medium between the plurality of inner flow paths (50a) of one heat transfer tube (50). As a result, the performance of the heat exchanger unit (40) can be improved.
  • A second aspect of the present disclosure is an embodiment of the first aspect. In the second aspect, the plate structure (62) has a plurality of plate members (65) stacked and joined to each other, and the first portion (80), the second portion (85), and the third portion (90) of the connection flow path (75) are formed in one of the plate members (65).
  • In the second aspect, the first portion (80), the second portion (85), and the third portion (90) of the connection flow path (75) are formed in one of the plate members (65).
  • A third aspect of the present disclosure is an embodiment of the first aspect. In the third aspect, the plate structure (62) has a plurality of plate members (65) stacked and joined to each other, the plurality of plate members (65) include a first plate member (71) and a second plate member (72) that is located on the opposite side of the heat transfer tubes (50) with respect to the first plate member (71), the first portion (80) and the second portion (85) of the connection flow path (75) are formed through both the first plate member (71) and the second plate member (72), and the third portion (90) of the connection flow path (75) is formed in only the second plate member (72) out of the first plate member (71) and the second plate member (72).
  • In the third aspect, the first portion (80) and the second portion (85) of the connection flow path (75) are formed through both the first plate member (71) and the second plate member (72). On the other hand, the third portion (90) of the connection flow path (75) is formed in the second plate member (72).
  • A fourth aspect of the present disclosure is an embodiment of any one of the first to third aspects. In the fourth aspect, a width of the first portion (80) is greater than equal to a width of the first heat transfer tube (51), a width of the second portion (85) is greater than equal to a width of the second heat transfer tube (52), and a width of the third portion (90) is less than or equal to the width of the first heat transfer tube (51) and less than or equal to the width of the second heat transfer tube (52).
  • In the connection flow path (75) of the fourth aspect, the width of the third portion (90) is less than or equal to the width of the first portion (80) and less than or equal to the width of the second portion (85).
  • A fifth aspect of the present disclosure is an embodiment of any one of the first to fourth aspects. In the fifth aspect, the first long side (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the same side as the second long side (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected.
  • In the fifth aspect, the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the same side as the second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected. For example, when one end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80), the other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85).
  • A sixth aspect of the present disclosure is an embodiment of the fifth aspect. In the sixth aspect, the third portion (90) has a straight portion (94) that is positioned so as to face the first long side (81a, 81b) and the second long side (86a, 86b).
  • In the connection flow path (75) of the sixth aspect, the third portion (90) includes the straight portion (94). The straight portion (94) is positioned so as to face each of the first long side (81a, 81b) of the first portion (80) and the second long side (86a, 86b) of the second portion (85).
  • A seventh aspect of the present disclosure is an embodiment of any one of the first to fourth aspects. In the seventh aspect, the first long side (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected.
  • In the seventh aspect, the first long side (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected. For example, when one end of the third portion (90) is connected to the first long side (81a), the upper one of the long sides of the first portion (80), the other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85).
  • An eighth aspect of the present disclosure is an embodiment of the seventh aspect. In the eighth aspect, a center line (L1) of the connection flow path (75) in a width direction is located above a straight line (L2) that connects a center point (CP1) of the first long side (81a, 81b) to which one end of the third portion (90) is connected and a center point (CP2) of the second long side (86a, 86b) to which the other end of the third portion (90) is connected.
  • In the eighth aspect, the center line (L1) of the connection flow path (75) is located above the straight line (L2) that connects the center point (CP1) of the first long side (81a, 81b) and the center point (CP2) of the second long side (86a. 86b).
  • A ninth aspect of the present disclosure is an embodiment of any one of the first to fourth aspects. In the ninth aspect, one end of the third portion (90) is connected to part of the first long side (81a, 81b) that includes the center point (CP1) of the first long side (81a, 81b), and the other end of the third portion (90) is connected to part of the second long side (86a, 86b) that includes the center point (CP2) of the second long side (86a, 86b).
  • In the ninth aspect, one end of the third portion (90) is connected to part of the first long side (81a, 81b) of the first portion (80) that includes the center point (CP1). The other end of the third portion (90) is connected to part of the second long side (86a, 86b) of the second portion (85) that includes the center point (CP2).
  • A tenth aspect of the present disclosure is directed to an air-conditioning indoor unit (30) including: the heat exchanger unit (40) of any one of the first to ninth aspects, wherein the heat exchanger unit (40) exchanges heat between the heat medium and indoor air.
  • In the tenth aspect, the heat exchanger unit (40) of any one of the first to ninth aspects is provided in the air-conditioning indoor unit (30).
  • An eleventh aspect of the present disclosure is directed to a refrigeration cycle apparatus (10) including: a refrigerant circuit (11) having the heat exchanger unit (40) of any one of the first to ninth aspects, wherein the refrigerant circuit (11) circulates a refrigerant to perform a refrigeration cycle.
  • In the eleventh aspect, the heat exchanger unit (40) of any one of the first to ninth aspects is provided in the refrigerant circuit (11) of the refrigeration cycle apparatus (10).
    • BRIEF DESCRIPTION OF THE DRAWINGS
    • [FIG. 1] FIG. 1 is a piping diagram showing a refrigerant circuit of an air conditioner according to the first embodiment.
    • [FIG. 2] FIG. 2 is a schematic front view of an indoor unit according to the first embodiment.
    • [FIG. 3] FIG. 3 is a schematic cross-sectional view of the indoor unit according to the first embodiment.
    • [FIG. 4] FIG. 4 is a schematic front view of a heat exchanger unit provided in the indoor unit according to the first embodiment.
    • [FIG. 5] FIG. 5 is a cross-sectional view of main portions of a second plate stack and a heat transfer tube in the heat exchanger unit according to the first embodiment.
    • [FIG. 6] FIG. 6 is a cross-sectional view of a main portion of the second plate stack in the heat exchanger unit according to the first embodiment.
    • [FIG. 7] FIG. 7 is a cross-sectional view of a main portion of a second plate stack in a heat exchanger unit according to a first variation of the first embodiment.
    • [FIG. 8] FIG. 8 is a cross-sectional view of a main portion of a second plate stack in a heat exchanger unit according to a second variation of the first embodiment.
    • [FIG. 9] FIG. 9 is a cross-sectional view of a main portion of a second plate stack in a heat exchanger unit according to a third variation of the first embodiment.
    • [FIG. 10] FIG. 10 is a cross-sectional view of main portions of a second plate stack and a heat transfer tube in a heat exchanger unit according to a second embodiment.
    • [FIG. 11] FIG. 11 is a cross-sectional view of a main portion of the second plate stack in the heat exchanger unit according to the second embodiment.
    • [FIG. 12] FIG. 12 is a cross-sectional view of a main portion of a second plate stack in a heat exchanger unit according to a first variation of the second embodiment.
    • [FIG. 13] FIG. 13 is a cross-sectional view of a main portion of a second plate stack in a heat exchanger unit according to a second variation of the second embodiment.
    • [FIG. 14] FIG. 14 is a schematic cross-sectional view of an indoor unit according to a third embodiment.
    • [FIG. 15] FIG. 15 is a cross-sectional view of a main portion of a second plate stack in a heat exchanger unit according to the third embodiment.
    • [FIG. 16] FIG. 16 is a cross-sectional view of main portions of a second plate stack and a heat transfer tube in a heat exchanger unit according to a first variation of other embodiments.
    DESCRIPTION OF EMBODIMENT <<First Embodiment>>
  • The first embodiment will be described.
    • -General Configuration of Air Conditioner-
  • The present embodiment is directed to an air conditioner (10) that includes a heat exchanger unit (40). The air conditioner (10) adjusts the temperature of air in an indoor space (200) as a target space.
  • As shown in FIG. 1, the air conditioner (10) is an example of a refrigeration cycle apparatus that includes a refrigerant circuit (11). The refrigerant circuit (11) is filled with a refrigerant which is a heat medium. The refrigerant circuit (11) circulates the refrigerant to perform a refrigeration cycle.
  • The air conditioner (10) includes an outdoor unit (20), an indoor unit (30), a first connection pipe (12), and a second connection pipe (13). The air conditioner (10) is a pair-type air conditioner that includes one outdoor unit (20) and one indoor unit (30). The first connection pipe (12) is a gas connection pipe, and the second connection pipe (13) is a liquid connection pipe. In the air conditioner (10), the outdoor unit (20) and the indoor unit (30) are connected by the first connection pipe (12) and the second connection pipe (13) to form the refrigerant circuit (11).
  • The outdoor unit (20) is installed outdoors. The outdoor unit (20) includes an outdoor casing (20a); and a compressor (21), an outdoor heat exchanger (22), an outdoor expansion valve (23), a four-way switching valve (24), and an outdoor fan (25) which are housed in the outdoor casing (20a).
  • The compressor (21) is a rotary compressor of an oscillating piston type, a rotary type, a scroll type, or the like. The outdoor heat exchanger (22) is a fin-and-tube air heat exchanger. The outdoor heat exchanger (22) exchanges heat between the refrigerant and the outdoor air. The outdoor expansion valve (23) is an electronic expansion valve of which the opening degree is variable. The four-way switching valve (24) switches between a first state (the state indicated by the solid lines in FIG. 1) and a second state (the state indicated by the broken lines in FIG. 1). The four-way switching valve (24) in the first state allows a discharge portion of the compressor (21) and a gas end portion of the outdoor heat exchanger (22) to communicate with each other, and allows a suction portion of the compressor (21) and the first connection pipe (12) to communicate with each other. The four-way switching valve (24) in the second state allows the discharge portion of the compressor (21) and the first connection pipe (12) to communicate with each other, and allows the suction portion of the compressor (21) and the gas end portion of the outdoor heat exchanger (22) to communicate with each other. The outdoor fan (25) is a propeller fan.
  • The indoor unit (30) includes a casing (31) and a heat exchanger unit (40) and an indoor fan (32) which are housed in the casing (31).
    • -Operation of Air Conditioner-
  • The air conditioner (10) selectively performs a cooling operation and a heating operation.
  • In the cooling operation, the four-way switching valve (24) is set to the state indicated by the solid line in FIG. 1. When the compressor (21) is operated, the refrigerant circuit (11) circulates the refrigerant to perform the refrigeration cycle. In the refrigerant circuit (11), the outdoor heat exchanger (22) functions as a condenser, and an indoor heat exchanger (41) functions as an evaporator. The indoor unit (30) blows the air cooled in the indoor heat exchanger (41) into the indoor space (200).
  • In the heating operation, the four-way switching valve (24) is set to the state indicated by the broken line in FIG. 1. When the compressor (21) is operated, the refrigerant circuit (11) circulates the refrigerant to perform the refrigeration cycle. In the refrigerant circuit (11), the indoor heat exchanger (41) functions as a condenser, and the outdoor heat exchanger (22) functions as an evaporator. The indoor unit (30) blows the air heated in the indoor heat exchanger (41) into the indoor space (200).
    • -Indoor Unit-
  • The indoor unit (30) as an indoor air-conditioning unit will be described in detail with reference to FIG. 2 and FIG. 3. The indoor unit (30) of this embodiment is a wall-mounted unit provided on a wall of the indoor space (200). The terms "upper", "lower", "right", "left", "front", and "back" described below correspond to the directions of the arrows shown in FIG. 2 and FIG. 3, and indicate the directions in which the indoor unit (30) is viewed from the front side.
    • <Casing>
  • The casing (31) is formed in a laterally-long box shape.
  • An inlet opening (33) is formed in an upper part of the casing (31). The inlet opening (33) extends in the longitudinal direction (the left-right direction) of the casing (31). An outlet opening (34) is formed in a lower part of the casing (31). The outlet opening (34) extends in the longitudinal direction of the casing (31).
    • <Heat Exchanger Unit>
  • The heat exchanger unit (40) includes one indoor heat exchanger (41) and one indoor expansion valve (42). The indoor heat exchanger (41) includes one heat exchanger body (45) and two plate stacks (61, 62).
    • <Indoor Fan>
  • The indoor fan (32) is a cross-flow fan. The indoor fan (32) is disposed below the heat exchanger unit (40). A fan rotor of the indoor fan (32) extends in the longitudinal direction of the casing (31).
    • <Flap>
  • The indoor unit (30) has a flap (36) that adjusts the direction of the air discharged from the outlet opening (34). The flap (36) adjusts the air direction in the upper-lower direction. The indoor unit (30) may have a plurality of flaps (36). The flap (36) may adjust the air direction in the left-right direction.
    • -Heat Exchanger Unit-
  • As described above, the heat exchanger unit (40) includes the indoor heat exchanger (41) and the indoor expansion valve (42).
    • <Indoor Heat Exchanger>
  • As described above, the indoor heat exchanger (41) includes one heat exchanger body (45) and two plate stacks (61, 62). The indoor heat exchanger (41) is a fin-and-tube air heat exchanger. The indoor heat exchanger (41) exchanges heat between the refrigerant and the indoor air. Each of the plate stacks (61, 62) is a plate structure. The number of plate stacks (61, 62) in the indoor heat exchanger (41) is merely an example.
    • <Heat Exchanger Body>
  • As shown in FIG. 3, the heat exchanger body (45) includes a first heat exchange portion (46), a second heat exchange portion (47), and a third heat exchange portion (48). The first heat exchange portion (46) and the second heat exchange portion (47) form a front heat exchange portion (45A). The third heat exchange portion (48) forms a rear heat exchange portion (45B). The number of heat exchange portions in the heat exchanger body (45) is merely an example. The number of heat exchange portions in the heat exchanger body (45) may be one, or may be two or more.
  • The front heat exchange portion (45A) is located on the front side of the casing (31). The rear heat exchange portion (45B) is located on the rear side of the casing (31). The heat exchanger body (45) is provided to cover the front side, the upper side, and the back side of the indoor fan (32).
    • <Indoor Expansion Valve>
  • The indoor expansion valve (42) is an electronic expansion valve of which the opening degree is variable. As shown in FIG. 1, one end of the indoor expansion valve (42) is connected to the front heat exchange portion (45A) by a pipe. The other end of the indoor expansion valve (42) is connected to the rear heat exchange portion (45B) by a pipe.
    • <First Heat Exchange Portion, Second Heat Exchange Portion, and Third Heat Exchange Portion>
  • As shown in FIG. 3, each of the first heat exchange portion (46), the second heat exchange portion (47), and the third heat exchange portion (48) includes a plurality of fins (53) and a plurality of heat transfer tubes (50). The material of the fin (53) and the heat transfer tube (50) is aluminum alloy. The material of the fin (53) and the heat transfer tube (50) may be metal other than aluminum alloy.
  • The fin (53) is a thin plate member that has a substantially rectangular shape. In each of the heat exchange portions (46, 47, 48), the plurality of fins (53) are arranged in a line in the left-right direction in FIG. 4, as well as facing each other and being spaced apart from each other at regular intervals.
  • As shown in FIG. 3, the heat transfer tube (50) is a flat tube of which the cross section is shaped into an elongated circle. The heat transfer tube (50) is a straight tube. The outer surface of the heat transfer tube (50) includes a pair of flat surfaces. In each of the heat exchange portions (46, 47, 48), the plurality of heat transfer tubes (50) are arranged in the direction of the long side of the fin (53), as well as their flat surfaces facing each other and being spaced apart from each other at regular intervals.
  • Each of the heat exchange portions (46, 47, 48) includes a first tube row (56) and a second tube row (57). Each of the first tube row (56) and the second tube row (57) includes the plurality of heat transfer tubes (50). In each of the first tube row (56) and the second tube row (57), the plurality of heat transfer tubes (50) are arranged in a line along the long side of the fin (53) as well as being spaced apart from each other at regular intervals.
  • The heat transfer tubes (50) forming the first tube row (56) are first heat transfer tubes (51). In the first tube row (56), the plurality of first heat transfer tubes (51) are arranged in a line at regular pitches. The heat transfer tubes (50) forming the second tube row (57) are second heat transfer tubes (52). In the second tube row (57), the plurality of second heat transfer tubes (52) are arranged in a line at regular pitches. The pitch of the first heat transfer tubes (51) in the first tube row (56) and the pitch of the second heat transfer tubes (52) in the second tube row (57) are equal to each other.
  • In each of the heat exchange portions (46, 47, 48), the first tube row (56) is along the long side of the fin (53) that is located windward, and the second tube row (57) is along the long side of the fin (53) that is located leeward. In each of the heat exchange portions (46, 47, 48), the first heat transfer tubes (51) of the first tube row (56) and the second heat transfer tubes (52) of the second tube row (57) are arranged in the direction of the short side of the fin (53). Accordingly, each of the first heat transfer tubes (51) and one of the second heat transfer tubes (52) that is closest to that first heat transfer tube (51) are disposed at the same position in the direction of the long side of the fin (53).
  • The first heat exchange portion (46) is disposed so that the long side of the fin (53) that is located windward is directed frontward and obliquely upward. The second heat exchange portion (47) is disposed so that the long side of the fin (53) that is located windward is directed frontward and obliquely downward. The second heat exchange portion (47) is disposed below the first heat exchange portion (46). The third heat exchange portion (48) is disposed so that the long side of the fin (53) that is located windward is directed backward and obliquely upward.
    • <Heat Transfer Tube>
  • As shown in FIG. 5 and FIG. 6, the heat transfer tube (50) is a flat tube of which the cross section is shaped into an elongated circle. The heat transfer tube (50) is also a straight tube. The total length of the heat transfer tube (50) is the distance from one end surface to the other end surface of the heat transfer tube (50). The width Wt of the heat transfer tube (50) is the length of the cross section of the heat transfer tube (50) in the longitudinal direction. The thickness THt of the heat transfer tube (50) is the length of the cross section of the heat transfer tube (50) in the transverse direction. The plurality of heat transfer tubes (50) in each of the heat exchange portions (46, 47, 48) have substantially the same width Wt and substantially the same thickness THt.
  • The heat transfer tube (50) includes a plurality of inner flow paths (50a). In the example shown in FIG. 5 and FIG. 6, the heat transfer tube (50) includes five inner flow paths (50a). The inner flow path (50a) is a straight flow path formed from one end to the other end of the heat transfer tube (50). The inner flow path (50a) is open in one end surface and the other end surface of the heat transfer tube (50). In the heat transfer tube (50), the plurality of inner flow paths (50a) are disposed in parallel to each other. In the heat transfer tube (50), the plurality of inner flow paths (50a) are arranged in a line in the width direction of the heat transfer tube (50).
    • <First Plate Stack and Second Plate Stack>
  • Each of a first plate stack (61) and a second plate stack (62) is a thick plate member formed by stacking a plurality of plate members. In each of the plate stacks (61, 62), a refrigerant flow path is formed to allow two heat transfer tubes (50) or three or more heat transfer tubes (50) to communicate with each other.
  • In each of the plate stacks (61, 62), the plurality of plate members (65) that form each plate stack is joined to each other by brazing. The plurality of plate members (65) that form each of the plate stacks (61, 62) is made of aluminum alloy. The material of the plate member (65) may be metal other than aluminum alloy.
  • The first plate stack (61) is disposed on the right side of the heat exchanger body (45) in FIG. 4. The first plate stack (61) is joined to one end portions of the heat transfer tubes (50) of each of the heat exchange portions (46, 47, 48).
  • The second plate stack (62) is disposed on the left side of the heat exchanger body (45) in FIG. 4. The second plate stack (62) is joined to the other end portions of the heat transfer tubes (50) of each of the heat exchange portions (46, 47, 48).
    • -Second Plate Stack-
  • The second plate stack (62) will be described with reference to FIG. 5. FIG. 5 shows the cross section of part of the second plate stack (62) that is connected to the heat transfer tubes (50) of the first heat exchange portion (46). In FIG. 5, the 5A-5A cross section and the 5B-5B cross section are the cross sections taken along the cut lines shown in the 5C-5C cross section. The 5C-5C cross section is the cross section taken along the cut lines shown in the 5A-5A cross section and the 5B-5B cross section.
  • The second plate stack (62) of this embodiment includes three plate members (65). The number of plate members (65) in the second plate stack (62) may be four or more.
  • Specifically, the second plate stack (62) includes a base plate (70), a first plate (71), and a second plate (72). Each of the base plate (70), the first plate (71), and the second plate (72) is the plate member (65). Each of the base plate (70), the first plate (71), and the second plate (72) is shaped into a flat plate.
  • In the second plate stack (62), the base plate (70), the first plate (71), and the second plate (72), each of which is close to the heat transfer tube (50) in this order, are disposed in the same order. The second plate (72) is disposed on the opposite side of the heat transfer tube (50) with respect to the first plate (71). The base plate (70) is joined to the first plate (71) by brazing, and the first plate (71) is joined to the second plate (72) by brazing.
  • The end portions of the first heat transfer tubes (51) forming the first tube row (56) and the end portions of the second heat transfer tubes (52) forming the second tube row (57) are inserted into the base plate (70). The first heat transfer tubes (51) and the second heat transfer tubes (52) are joined to the base plate (70) by brazing.
  • A connection flow path (75) is formed in the first plate (71). The connection flow path (75) is a hole that runs through the first plate (71). The connection flow path (75) is a refrigerant flow path that allows one first heat transfer tube (51) and one second heat transfer tube (52) to communicate with each other.
  • The connection flow path (75) shown in FIG. 5 connects one first heat transfer tube (51) and one second heat transfer tube (52) adjacent to the first one of the first heat transfer tubes (51) that is located above and counted from the one first heat transfer tube (51). The connection flow path (75) communicates with all the inner flow paths (50a) formed in the first heat transfer tube (51), and communicates with all the inner flow paths (50a) formed in the second heat transfer tube (52).
  • The second plate (72) covers the connection flow path (75) of the first plate (71) to seal the connection flow path (75).
    • -Connection Flow Path of Second Plate Stack-
  • The connection flow path (75) formed in the second plate stack (62) will be described with reference to FIG. 6. FIG. 6 is an enlarged view of the "5C-5C cross section" shown in FIG. 5.
  • The connection flow path (75) is divided into a first portion (80), a second portion (85), and a third portion (90).
    • <First Portion>
  • The first portion (80) is a portion that overlaps with the end surface of the first heat transfer tube (51) when viewed from the front side of the end surface of the first heat transfer tube (51). The first portion (80) overlaps with the entire part of the end surface of the first heat transfer tube (51). The shape of the first portion (80) as viewed in the stacking direction of the plate members (65) in the second plate stack (62) (in other words, the shape illustrated in FIG. 6) is substantially the same as the shape of the end surface of the first heat transfer tube (51). The width Wp1 of the first portion (80) is substantially equal to the width Wt of the first heat transfer tube (51).
  • The first portion (80) covers the end surface of the first heat transfer tube (51). The first portion (80) faces the end surface of the first heat transfer tube (51). The first portion (80) communicates with all the inner flow paths (50a) formed in the first heat transfer tube (51) (the five inner flow paths (50a) in the example of FIG. 6).
  • The first portion (80) has a pair of first long sides (81a, 81b) and a pair of first semicircular portions (82a, 82b). Each of the first long sides (81a, 81b) is a straight portion that extends along the width direction of the first heat transfer tube (51). The first long sides (81a, 81b) are substantially parallel to each other. Each of the first semicircular portions (82a, 82b) is a curved portion that is shaped into a semicircular arc. The first semicircular portion (82a), one of the first semicircular portions, is connected to one end of each of the first long sides (81a, 81b). The first semicircular portion (82b), the other one of the first semicircular portions, is connected to the other end of each of the first long sides (81a, 81b).
    • <Second Portion>
  • The second portion (85) is a portion that overlaps with the end surface of the second heat transfer tube (52) when viewed from the front side of the end surface of the second heat transfer tube (52). The second portion (85) overlaps with the entire part of the end surface of the second heat transfer tube (52). The shape of the second portion (85) as viewed in the stacking direction of the plate members (65) in the second plate stack (62) (in other words, the shape illustrated in FIG. 6) is substantially the same as the shape of the end surface of the second heat transfer tube (52). The width Wp2 of the second portion (85) is substantially equal to the width Wt of the second heat transfer tube (52).
  • The second portion (85) covers the end surface of the second heat transfer tube (52). The second portion (85) faces the end surface of the second heat transfer tube (52). The second portion (85) communicates with all the inner flow paths (50a) formed in the second heat transfer tube (52) (the five inner flow paths (50a) in the example of FIG. 6).
  • The second portion (85) has a pair of second long sides (86a, 86b) and a pair of second semicircular portions (87a, 87b). Each of the second long sides (86a, 86b) is a straight portion that extends along the width direction of the second heat transfer tube (52). The second long sides (86a, 86b) are substantially parallel to each other. Each of the second semicircular portions (87a, 87b) is a curved portion that is shaped into a semicircular arc. The second semicircular portion (87a), one of the second semicircular portions, is connected to one end of each of the second long sides (86a, 86b). The second semicircular portion (87b), the other one of the second semicircular portions, is connected to the other end of each of the second long sides (86a, 86b).
    • <Third Portion>
  • The third portion (90) is a portion that connects the first portion (80) and the second portion (85). The third portion (90) communicates with both the first portion (80) and the second portion (85).
  • The third portion (90) extends straight in the oblique direction from the first portion (80) to the second portion (85). The side portion (90a), one of the side portions of the third portion (90), is a straight portion that connects the first semicircular portion (82a), one of the semicircular portions of the first portion (80), and the second semicircular portion (87a), one of the semicircular portions of the second portion (85). The side portion (90b), the other one of the side portions of the third portion (90), is a straight portion that connects the first semicircular portion (82b), the other one of the semicircular portions of the first portion (80), and the second semicircular portion (87b), the other one of the semicircular portions of the second portion (85).
  • One end of the third portion (90) is connected to the first long side (81a), the upper one of the long sides of the first portion (80), and the first semicircular portion (82b), the other one of the semicircular portions of the first portion (80). Accordingly, one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80). In addition, one end of the third portion (90) is connected to the entire part of the first long side (81a). Accordingly, one end of the third portion (90) is connected to part of the first long side (81a) that includes the center point (CP1) of the first long side (81a).
  • The other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85), and the second semicircular portion (87a), the other one of the semicircular portions of the second portion (85). Accordingly, the other end of the third portion (90) is connected to only one of the pair of second long sides (86a, 86b) of the second portion (85). In addition, the other end of the third portion (90) is connected to the entire part of the second long side (86b). Accordingly, the other end of the third portion (90) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b).
  • One end of the third portion (90) is connected to the first long side (81a), the upper one of the long sides of the first portion (80); and the other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85). Accordingly, the first long side (81a) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected is one of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81a) of the first portion (80) to which one end of the third portion (90) is connected.
    • -Refrigerant Flow in Connection Flow Path-
  • In the connection flow path (75) of the second plate stack (62), the refrigerant flows from one of the first heat transfer tube (51) and the second heat transfer tube (52) to the other. The direction in which the refrigerant flows in the indoor heat exchanger (41) is reversed between the cooling operation and the heating operation. Thus, for example, if the refrigerant flows in the connection flow path (75) from the second heat transfer tube (52) to the first heat transfer tube (51) in the cooling operation, the refrigerant flows in the connection flow path (75) from the first heat transfer tube (51) to the second heat transfer tube (52) in the heating operation.
    • <First Heat Transfer Tube to Second Heat Transfer Tube>
  • The refrigerant flow in the connection flow path (75) where the refrigerant flows from the first heat transfer tube (51) to the second heat transfer tube (52) will be described.
  • The refrigerant that flows in each of the inner flow paths (50a) of the first heat transfer tube (51) flows into and joins in the first portion (80) of the connection flow path (75). The refrigerant having joined in the first portion (80) flows through the third portion (90), and then flows into the second portion (85). The refrigerant having flowed into the second portion (85) separately flows into the inner flow paths (50a) of the second heat transfer tube (52).
  • As described above, the other end of the third portion (90) is connected to the entire part of the second long side (86b) of the second portion (85). All the inner flow paths (50a) arranged in a line in the width direction of the second heat transfer tube (52) are open in the end surface of the second heat transfer tube (52) that faces the second portion (85). Thus, the refrigerant having flowed from the third portion (90) into the second portion (85) is substantially evenly distributed to all the inner flow paths (50a) formed in the second heat transfer tube (52).
    • <Second Heat Transfer Tube to First Heat Transfer Tube>
  • The refrigerant flow in the connection flow path (75) where the refrigerant flows from the second heat transfer tube (52) to the first heat transfer tube (51) will be described.
  • The refrigerant that flows in each of the inner flow paths (50a) of the second heat transfer tube (52) flows into and joins in the second portion (85) of the connection flow path (75). The refrigerant having joined in the second portion (85) flows through the third portion (90), and then flows into the first portion (80). The refrigerant having flowed into the first portion (80) is divided into flows into each of the inner flow paths (50a) of the first heat transfer tube (51).
  • As described above, the other end of the third portion (90) is connected to the entire part of the first long side (81a) of the first portion (80). All the inner flow paths (50a) arranged in a line in the width direction of the first heat transfer tube (51) are open in the end surface of the first heat transfer tube (51) that faces the first portion (80). Thus, the refrigerant having flowed from the third portion (90) into the first portion (80) is substantially evenly distributed to all the inner flow paths (50a) formed in the first heat transfer tube (51).
    • -Features of First Embodiment-
  • In the heat exchanger unit (40) of this embodiment, when the refrigerant flows in the connection flow path (75) from the first heat transfer tube (51) to the second heat transfer tube (52), the heat medium flowing in the third portion (90) flows into the second portion (85) from the second long sides (86a, 86b) extending along the width direction of the second heat transfer tube (52), and then is substantially evenly distributed to all the plurality of inner flow paths (50a) arranged in the width direction of the second heat transfer tube (52). When the refrigerant flows in the connection flow path (75) from the second heat transfer tube (52) to the first heat transfer tube (51), the heat medium flowing in the third portion (90) flows into the first portion (80) from the first long sides (81a, 81b) extending along the width direction of the first heat transfer tube (51), and then is substantially evenly distributed to all the plurality of inner flow paths (50a) arranged in the width direction of the first heat transfer tube (51).
  • In the heat exchanger unit (40) of this embodiment, the refrigerant flowing in the connection flow path (75) is substantially evenly distributed to all the inner flow paths (50a) formed in the heat transfer tube (50), and thus there is only small difference in the flow rate of the refrigerant between the plurality of inner flow paths (50a) of one heat transfer tube (50). Accordingly, according to this embodiment, the performance of the heat exchanger unit (40) can be improved.
    • -First Variation of First Embodiment-
  • The connection flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path that is shaped as shown in FIG. 7. In the connection flow path (75) shown in FIG. 7, the third portion (90) is divided into a first end portion (91), a second end portion (92), and a middle portion (93).
  • The first end portion (91) is a portion that includes one end of the connection flow path (75). The first end portion (91) is connected to the entire part of the first long side (81a), the upper one of the long sides of the first portion (80). Accordingly, the first end portion (91) is connected to part of the first long side (81a) that includes the center point (CP 1) of the first long side (81a). The width of the first end portion (91) is substantially equal to the width Wp1 of the first portion (80).
  • The second end portion (92) is a portion that includes the other end of the connection flow path (75). The second end portion (92) is connected to the entire part of the second long side (86b), the lower one of the long sides of the second portion (85). Accordingly, the second end portion (92) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b). The width of the second end portion (92) is substantially equal to the width Wp2 of the second portion (85).
  • The middle portion (93) is a portion that connects the first end portion (91) and the second end portion (92). The middle portion (93) extends straight in the oblique direction from the first end portion (91) to the second end portion (92). The width Wp3 of the middle portion (93) is slightly narrower than each of the width Wp1 of the first portion (80) and the width Wp2 of the second portion (85).
    • -Second Variation of First Embodiment-
  • The connection flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path that is shaped as shown in FIG. 8. In the connection flow path (75) shown in FIG. 8, the third portion (90) is divided into a first end portion (91), a second end portion (92), and a middle portion (93).
  • The first end portion (91) is a portion that includes one end of the connection flow path (75). The first end portion (91) is connected to the entire part of the first long side (81a), the upper one of the long sides of the first portion (80). Accordingly, the first end portion (91) is connected to part of the first long side (81a) that includes the center point (CP 1) of the first long side (81a). The width of the first end portion (91) is gradually narrowed toward the upper side from the first long side (81a), the upper one of the long sides of the first portion (80).
  • The second end portion (92) is a portion that includes the other end of the connection flow path (75). The second end portion (92) is connected to the entire part of the second long side (86b), the lower one of the long sides of the second portion (85). Accordingly, the second end portion (92) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b). The width of the second end portion (92) is gradually narrowed toward the lower side from the second long side (86b), the lower one of the long sides of the second portion (85).
  • The middle portion (93) is a portion that connects the first end portion (91) and the second end portion (92). The middle portion (93) extends straight in the oblique direction from the first end portion (91) to the second end portion (92). The width Wp3 of the middle portion (93) is extremely narrower than each of the width Wp1 of the first portion (80) and the width Wp2 of the second portion (85).
    • -Third Variation of First Embodiment-
  • The connection flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path that is shaped as shown in FIG. 9.
  • In the connection flow path (75) shown in FIG. 9, the side portion (90b) on the lower side is formed in a curved shape that is raised upward. One end of the side portion (90b) is connected to the vicinity of the other end of the first long side (81a), the upper one of the long sides of the first portion (80). The other end of the side portion (90b) is connected to the vicinity of the other end of the second long side (86b), the lower one of the long sides of the second portion (85).
  • A center line (L1) of the connection flow path (75) in the width direction is located above a straight line (L2) that connects the center point (CP1) of the first long side (81a) of the first portion (80) and the center point (CP2) of the second long side (86b) of the second portion (85).
  • Here, when the air conditioner (10) is operating, a refrigerant in the gas-liquid two-phase state may flow in the connection flow path (75). When the refrigerant in the gas-liquid two-phase state flows in the connection flow path (75), the gas refrigerant may be locally distributed in a region that extends along the side portion (90a), the upper one of the side portions of the connection flow path (75); and the liquid refrigerant may be locally distributed in a region that extends along the side portion (90b), the lower one of the side portions of the connection flow path (75). As a result, the ratio between the liquid refrigerant and the gas refrigerant in the refrigerant that flows into each of the inner flow paths (50a) of the heat transfer tube (50) may not be uniform.
  • On the other hand, in the connection flow path (75) of this variation, the side portion (90b) on the lower side is formed in a curved shape that is raised upward. Further, in this variation, the center line (L1) of the connection flow path (75) in the width direction is located above the straight line (L2) that connects the center point (CP1) of the first long side (81a) and the center point (CP2) of the second long side (86b). Thus, when the refrigerant in the gas-liquid two-phase state flows in the connection flow path (75) of this variation, the mixing ratio between the gas refrigerant and the liquid refrigerant in the entire part of the connection flow path (75) is more uniform than when the refrigerant in the gas-liquid two-phase state flows in the connection flow path (75) of FIG. 6.
  • Accordingly, according to this variation, the ratio between the liquid refrigerant and the gas refrigerant in the refrigerant that flows from the connection flow path (75) into each of the inner flow paths (50a) of the heat transfer tube (50) can be uniform.
    • -Fourth Variation of First Embodiment-
  • The connection flow path (75) formed in the second plate stack (62) of this embodiment connects one first heat transfer tube (51) and one second heat transfer tube (52) adjacent to the first one of the first heat transfer tubes (51) that is located below and counted from the one first heat transfer tube (51).
  • In the connection flow path (75) of this variation, one end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80). One end of the third portion (90) is connected to the entire part of the first long side (81b). Accordingly, one end of the third portion (90) is connected to part of the first long side (81b) that includes the center point of the first long side (81b).
  • In the connection flow path (75) of this variation, the other end of the third portion (90) is connected to the second long side (86a), the upper one of the long sides of the second portion (85). The other end of the third portion (90) is connected to the entire part of the second long side (86a). Accordingly, the other end of the third portion (90) is connected to part of the second long side (86a) that includes the center point of the second long side (86a).
  • In the connection flow path (75) of this variation, one end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80); and the other end of the third portion (90) is connected to the second long side (86a), the upper one of the long sides of the second portion (85). Accordingly, the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected is one of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected.
  • This variation can also be applied to the connection flow paths (75) of the first to third variations of this embodiment.
    • -Fifth Variation of First Embodiment-
  • In the connection flow path (75) of this embodiment, one end of the third portion (90) may be connected to part of the first long side (81a), the upper one of the long sides of the first portion (80). In this variation, one end of the third portion (90) is connected to part of the first long side (81a) that includes the center point (CP1) of the first long side (81a) in one preferred embodiment. In this variation, one end of the third portion (90) is connected to half or more of the first long side (81a) in one preferred embodiment.
  • This variation can also be applied to the connection flow paths (75) of the first to fourth variations of this embodiment.
    • -Sixth Variation of First Embodiment-
  • In the connection flow path (75) of this embodiment, the other end of the third portion (90) may be connected to part of the second long side (86b), the lower one of the long sides of the second portion (85). In this variation, one end of the third portion (90) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b) in one preferred embodiment. In this variation, one end of the third portion (90) is connected to half or more of the second long side (86b) in one preferred embodiment.
  • This variation can also be applied to the connection flow paths (75) of the first to fifth variations of this embodiment.
    • <<Second Embodiment>>
  • The second embodiment will be described.
  • In the air conditioner (10) of this embodiment, the connection flow path (75) formed in the second plate stack (62) of the heat exchanger unit (40) is different from the connection flow path (75) of the first embodiment. Regarding the connection flow path (75) formed in the second plate stack (62) of this embodiment, the following description will focus on the difference from the connection flow path (75) of the first embodiment.
    • -Connection Flow Path of Second Plate Stack-
  • FIG. 10 shows the cross section of part of the second plate stack (62) that is connected to the heat transfer tubes (50) of the first heat exchange portion (46). In FIG. 10, the 10A-10A cross section is the cross section taken along the cut line shown in the 10B-10B cross section. The 10B-10B cross section is the cross section taken along the cut line shown in the 10A-10A cross section.
  • As shown in FIG. 10, the connection flow path (75) of this embodiment connects one first heat transfer tube (51) and one second heat transfer tube (52) adjacent to the one first heat transfer tube (51). Accordingly, the connection flow path (75) of this embodiment connects one first heat transfer tube (51) and one second heat transfer tube (52) that is closest to that first heat transfer tube (51). Similarly to the connection flow path (75) of the first embodiment, the connection flow path (75) of this embodiment is formed in the first plate (71).
  • As shown in FIG. 11, the connection flow path (75) is divided into the first portion (80), the second portion (85), and the third portion (90).
    • <First Portion>
  • The first portion (80) of this embodiment has the same shape as the first portion (80) of the first embodiment. Similarly to the first portion (80) of the first embodiment, the first portion (80) of this embodiment overlaps with the entire part of the end surface of the first heat transfer tube (51) and covers the end surface of the first heat transfer tube (51). The first portion (80) faces the end surface of the first heat transfer tube (51). The first portion (80) communicates with all the inner flow paths (50a) formed in the first heat transfer tube (51). The first portion (80) has the pair of first long sides (81a, 81b) and the pair of first semicircular portions (82a, 82b).
    • <Second Portion>
  • The second portion (85) of this embodiment has the same shape as the second portion (85) of the first embodiment. However, the second heat transfer tube (52) that corresponds to the second portion (85) of this embodiment is provided in a position that is different from where the second heat transfer tube (52) that corresponds to the second portion (85) of the first embodiment is provided. Similarly to the second portion (85) of the first embodiment, the second portion (85) of this embodiment overlaps with the entire part of the end surface of the second heat transfer tube (52) and covers the end surface of the second heat transfer tube (52). The second portion (85) faces the end surface of the second heat transfer tube (52). The second portion (85) communicates with all the inner flow paths (50a) formed in the second heat transfer tube (52). The second portion (85) has the pair of second long sides (86a, 86b) and the pair of second semicircular portions (87a, 87b).
    • <Third Portion>
  • The third portion (90) is a portion that connects the first portion (80) and the second portion (85). The third portion (90) communicates with both the first portion (80) and the second portion (85).
  • The third portion (90) is a V-shaped flow path that is located below the first portion (80) and the second portion (85). The third portion (90) formed in a V-shape includes a bottom portion in which a straight portion (94) that is made flat is formed. The straight portion (94) faces the first long side (81b), the lower one of the long sides of the first portion (80), and also faces the second long side (86b), the lower one of the long sides of the second portion (85).
  • One end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80). Accordingly, one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80). In addition, one end of the third portion (90) is connected to the entire part of the first long side (81b). Accordingly, one end of the third portion (90) is connected to part of the first long side (81b) that includes the center point (CP1) of the first long side (81b).
  • The other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85). Accordingly, the other end of the third portion (90) is connected to only one of the pair of second long sides (86a, 86b) of the second portion (85). In addition, the other end of the third portion (90) is connected to the entire part of the second long side (86b). Accordingly, the other end of the third portion (90) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b).
  • One end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80); and the other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85). Accordingly, the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the same side as the second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected is one of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected.
    • -Refrigerant Flow in Connection Flow Path-
  • Similarly to the first embodiment, in the connection flow path (75) of the second plate stack (62), the refrigerant flows from one of the first heat transfer tube (51) and the second heat transfer tube (52) to the other.
    • <First Heat Transfer Tube to Second Heat Transfer Tube>
  • The refrigerant flow in the connection flow path (75) where the refrigerant flows from the first heat transfer tube (51) to the second heat transfer tube (52) will be described.
  • The refrigerant that flows in each of the inner flow paths (50a) of the first heat transfer tube (51) flows into and joins in the first portion (80) of the connection flow path (75). The refrigerant having joined in the first portion (80) flows through the third portion (90), and then flows into the second portion (85). The refrigerant having flowed into the second portion (85) separately flows into the inner flow paths (50a) of the second heat transfer tube (52).
  • As described above, the other end of the third portion (90) is connected to the entire part of the second long side (86b) of the second portion (85). All the inner flow paths (50a) arranged in a line in the width direction of the second heat transfer tube (52) are open in the end surface of the second heat transfer tube (52) that faces the second portion (85). Thus, the refrigerant having flowed from the third portion (90) to the second portion (85) is substantially evenly distributed to all the inner flow paths (50a) formed in the second heat transfer tube (52).
    • <Second Heat Transfer Tube to First Heat Transfer Tube>
  • The refrigerant flow in the connection flow path (75) where the refrigerant flows from the second heat transfer tube (52) to the first heat transfer tube (51) will be described.
  • The refrigerant that flows in each of the inner flow paths (50a) of the second heat transfer tube (52) flows into and joins in the second portion (85) of the connection flow path (75). The refrigerant having joined in the second portion (85) flows through the third portion (90), and then flows into the first portion (80). The refrigerant having flowed into the first portion (80) separately flows into the inner flow paths (50a) of the first heat transfer tube (51).
  • As described above, the other end of the third portion (90) is connected to the entire part of the first long side (81b) of the first portion (80). All the inner flow paths (50a) arranged in a line in the width direction of the first heat transfer tube (51) are open in the end surface of the first heat transfer tube (51) that faces the first portion (80). Thus, the refrigerant having flowed from the third portion (90) into the first portion (80) is substantially evenly distributed to all the inner flow paths (50a) formed in the first heat transfer tube (51).
    • -Features of Second Embodiment-
  • Similarly to the heat exchanger unit (40) of the first embodiment, in the heat exchanger unit (40) of this embodiment, the refrigerant flowing in the connection flow path (75) is substantially evenly distributed to all the inner flow paths (50a) formed in the heat transfer tube (50), and thus there is only small difference in the flow rate of the refrigerant between the plurality of inner flow paths (50a) of one heat transfer tube (50). Accordingly, according to this embodiment, the performance of the heat exchanger unit (40) can be improved.
    • -First Variation of Second Embodiment-
  • The connection flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path that is shaped as shown in FIG. 12. The connection flow path (75) of this variation is different in the shape of the third portion (90) from the connection flow path (75) of FIG. 11.
  • The third portion (90) of this variation is a U-shaped flow path that is located below the first portion (80) and the second portion (85). The third portion (90) formed in a U-shape includes a bottom portion in which a straight portion (94) that is made flat is formed. Similarly to the straight portion (94) of the connection flow path (75) in FIG. 11, the straight portion (94) faces the first long side (81b), the lower one of the long sides of the first portion (80), and also faces the second long side (86b), the lower one of the long sides of the second portion (85).
    • -Second Variation of Second Embodiment-
  • The connection flow path (75) formed in the second plate stack (62) of this embodiment may be a flow path that is shaped as shown in FIG. 13. The connection flow path (75) of this variation is different in the shape of the third portion (90) from the connection flow path (75) of FIG. 11.
  • The third portion (90) of this variation is a U-shaped flow path that is located below the first portion (80) and the second portion (85). The entire part of the side wall portion of the third portion (90) of this variation is curved. Accordingly, the third portion (90) of this variation does not include the straight portion (94) that is made flat.
    • -Third Variation of Second Embodiment-
  • In the connection flow path (75) formed in the second plate stack (62) of this embodiment, the third portion (90) may be located above the first portion (80) and the second portion (85).
  • In the connection flow path (75) of this variation, one end of the third portion (90) is connected to the first long side (81a), the upper one of the long sides of the first portion (80). One end of the third portion (90) is connected to the entire part of the first long side (81a). Accordingly, one end of the third portion (90) is connected to part of the first long side (81a) that includes the center point of the first long side (81a).
  • The other end of the third portion (90) is connected to the second long side (86a), the upper one of the long sides of the second portion (85). The other end of the third portion (90) is connected to the entire part of the second long side (86a). Accordingly, the other end of the third portion (90) is connected to part of the second long side (86a) that includes the center point of the second long side (86a).
  • One end of the third portion (90) is connected to the first long side (81a), the upper one of the long sides of the first portion (80); and the other end of the third portion (90) is connected to the second long side (86a), the upper one of the long sides of the second portion (85). Accordingly, the first long side (81a) of the first portion (80) to which one end of the third portion (90) is connected is located on the same side as the second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected is one of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81a) of the first portion (80) to which one end of the third portion (90) is connected.
    • -Fourth Variation of Second Embodiment-
  • In the connection flow path (75) of this embodiment, one end of the third portion (90) may be connected to part of the first long side (81b), the lower one of the long sides of the first portion (80). In this variation, one end of the third portion (90) is connected to part of the first long side (81b) that includes the center point (CP1) of the first long side (81b) in one preferred embodiment. In this variation, one end of the third portion (90) is connected to half or more of the first long side (81b) in one preferred embodiment.
  • This variation can also be applied to the connection flow paths (75) of the first to third variations of this embodiment.
    • -Fifth Variation of Second Embodiment-
  • In the connection flow path (75) of this embodiment, the other end of the third portion (90) may be connected to part of the second long side (86b), the lower one of the long sides of the second portion (85). In this variation, one end of the third portion (90) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b) in one preferred embodiment. In this variation, one end of the third portion (90) is connected to half or more of the second long side (86b) in one preferred embodiment.
  • This variation can also be applied to the connection flow paths (75) of the first to fourth variations of this embodiment.
    • <<Third Embodiment>>
  • The third embodiment will be described.
  • The air conditioner (10) of this embodiment is different in the configuration of the heat exchanger unit (40) from the air conditioner (10) of the first embodiment. Regarding the heat exchanger unit (40) of this embodiment, the following description will focus on the difference from the heat exchanger unit (40) of the first embodiment.
    • -Layout of Heat Transfer Tubes-
  • As shown in FIG. 14, the heat exchanger unit (40) of this embodiment is different in the layout of the heat transfer tubes (50) in each of the heat exchange portions (46, 47, 48) from the heat exchanger unit of the first embodiment. In each of the heat exchange portions (46, 47, 48) of this embodiment, each of the first heat transfer tubes (51) and one of the second heat transfer tubes (52) that is closest to that first heat transfer tube (51) are disposed at different positions in the direction of the long side of the fin (53). In the direction of the long side of the fin (53), each of the first heat transfer tubes (51) forming the first tube row (56) is displaced with respect to each of the second heat transfer tubes (52) forming the second tube row (57) by half of the pitch at which the plurality of first heat transfer tubes (51) are arranged in the first tube row (56).
    • -Connection Flow Path of Second Plate Stack-
  • Similarly to the first embodiment, the connection flow path (75) is formed in the second plate stack (62) of this embodiment. The connection flow path (75) allows one first heat transfer tube (51) and one second heat transfer tube (52) closest to that first heat transfer tube (51) to communicate with each other. The connection flow path (75) of this embodiment allows one first heat transfer tube (51) to communicate with one of the two second heat transfer tubes (52) that are closest to that first heat transfer tube (51), where that one of the two second heat transfer tubes (52) is located above that first heat transfer tube (51).
  • The connection flow path (75) of this embodiment is formed in the same shape as the connection flow path (75) of the first embodiment shown in FIG. 6. Similarly to the connection flow path (75) of the first embodiment, the connection flow path (75) is divided into the first portion (80), the second portion (85), and the third portion (90).
    • <First Portion>
  • The first portion (80) of this embodiment has the same shape as the first portion (80) of the first embodiment. Similarly to the first portion (80) of the first embodiment, the first portion (80) of this embodiment overlaps with the entire part of the end surface of the first heat transfer tube (51) and covers the end surface of the first heat transfer tube (51). The first portion (80) faces the end surface of the first heat transfer tube (51). The first portion (80) communicates with all the inner flow paths (50a) formed in the first heat transfer tube (51). The first portion (80) has the pair of first long sides (81a, 81b) and the pair of first semicircular portions (82a, 82b).
    • <Second Portion>
  • The second portion (85) of this embodiment has the same shape as the second portion (85) of the first embodiment. Similarly to the second portion (85) of the first embodiment, the second portion (85) of this embodiment overlaps with the entire part of the end surface of the second heat transfer tube (52) and covers the end surface of the second heat transfer tube (52). The second portion (85) faces the end surface of the second heat transfer tube (52). The second portion (85) communicates with all the inner flow paths (50a) formed in the second heat transfer tube (52). The second portion (85) has the pair of second long sides (86a, 86b) and the pair of second semicircular portions (87a, 87b).
    • <Third Portion>
  • Similarly to the third portion (90) of the first embodiment, the third portion (90) of this embodiment extends straight in the oblique direction from the first portion (80) to the second portion (85) and connects the first portion (80) and the second portion (85).
  • One end of the third portion (90) is connected to the entire part of the first long side (81a). Accordingly, one end of the third portion (90) is connected to part of the first long side (81a) that includes the center point (CP1) of the first long side (81a). In addition, the other end of the third portion (90) is connected to the entire part of the second long side (86b). Accordingly, the other end of the third portion (90) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b).
  • One end of the third portion (90) is connected to the first long side (81a), the upper one of the long sides of the first portion (80); and the other end of the third portion (90) is connected to the second long side (86b), the lower one of the long sides of the second portion (85). Accordingly, the first long side (81a) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected is one of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81a) of the first portion (80) to which one end of the third portion (90) is connected.
    • -Refrigerant Flow in Connection Flow Path-
  • The refrigerant flow in the connection flow path (75) of this embodiment is the same as the refrigerant flow in the connection flow path (75) of the first embodiment.
  • When the refrigerant flows from the first heat transfer tube (51) to the second heat transfer tube (52), the refrigerant having flowed into the first portion (80) from each of the inner flow paths (50a) of the first heat transfer tube (51) flows into the second portion (85) through the third portion (90), and is substantially evenly distributed to all the inner flow paths (50a) formed in the second heat transfer tube (52).
  • When the refrigerant flows from the second heat transfer tube (52) to the first heat transfer tube (51), the refrigerant having flowed into the second portion (85) from each of the inner flow paths (50a) of the second heat transfer tube (52) flows into the first portion (80) through the third portion (90), and is substantially evenly distributed to all the inner flow paths (50a) formed in the first heat transfer tube (51).
    • -Features of Third Embodiment-
  • Similarly to the heat exchanger unit (40) of the first embodiment, in the heat exchanger unit (40) of this embodiment, the refrigerant flowing in the connection flow path (75) is substantially evenly distributed to all the inner flow paths (50a) formed in the heat transfer tube (50), and thus there is only small difference in the flow rate of the refrigerant between the plurality of inner flow paths (50a) of one heat transfer tube (50). Accordingly, according to this embodiment, the performance of the heat exchanger unit (40) can be improved.
    • -First Variation of Third Embodiment-
  • The connection flow path (75) of this embodiment formed in the second plate stack (62) may allow one first heat transfer tube (51) to communicate with one of the two second heat transfer tubes (52) that are closest to that first heat transfer tube (51), where that one of the two second heat transfer tubes (52) is located below that first heat transfer tube (51).
  • In the connection flow path (75) of this variation, one end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80). One end of the third portion (90) is connected to the entire part of the first long side (81b). Accordingly, one end of the third portion (90) is connected to part of the first long side (81b) that includes the center point of the first long side (81b).
  • In the connection flow path (75) of this variation, the other end of the third portion (90) is connected to the second long side (86a), the upper one of the long sides of the second portion (85). The other end of the third portion (90) is connected to the entire part of the second long side (86a). Accordingly, the other end of the third portion (90) is connected to part of the second long side (86a) that includes the center point of the second long side (86a).
  • In the connection flow path (75) of this variation, one end of the third portion (90) is connected to the first long side (81b), the lower one of the long sides of the first portion (80); and the other end of the third portion (90) is connected to the second long side (86a), the upper one of the long sides of the second portion (85). Accordingly, the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86b) of the second portion (85) to which the other end of the third portion (90) is connected. The second long side (86a) of the second portion (85) to which the other end of the third portion (90) is connected is one of the pair of second long sides (86a, 86b) of the second portion (85) that is closer to the first long side (81b) of the first portion (80) to which one end of the third portion (90) is connected.
    • -Second Variation of Third Embodiment-
  • The connection flow path (75) of this embodiment may employ the first to third variations of the first embodiment. That is, the shape of the connection flow path (75) of this embodiment may be the same shape as the connection flow path (75) shown in each of FIGS. 7 to 9.
    • -Third Variation of Third Embodiment-
  • In the connection flow path (75) of this embodiment, one end of the third portion (90) may be connected to part of the first long side (81a), the upper one of the long sides of the first portion (80). In this variation, one end of the third portion (90) is connected to part of the first long side (81a) that includes the center point (CP1) of the first long side (81a) in one preferred embodiment. In this variation, one end of the third portion (90) is connected to half or more of the first long side (81a) in one preferred embodiment.
  • This variation can also be applied to the connection flow paths (75) of the first and second variations of this embodiment.
    • -Fourth Variation of Third Embodiment-
  • In the connection flow path (75) of this embodiment, the other end of the third portion (90) may be connected to part of the second long side (86b), the lower one of the long sides of the second portion (85). In this variation, one end of the third portion (90) is connected to part of the second long side (86b) that includes the center point (CP2) of the second long side (86b) in one preferred embodiment. In this variation, one end of the third portion (90) is connected to half or more of the second long side (86b) in one preferred embodiment.
  • This variation can also be applied to the connection flow paths (75) of the first to third variations of this embodiment.
    • <<Other Embodiments>>
  • The heat exchanger unit of the above embodiments may employ the following variations. The following variations may be combined or replaced as necessary only if the function of the heat exchanger unit is not impaired.
    • -First Variation-
  • In each of the first to third embodiments, the second plate stack (62) may include four plate members (65).
  • The second plate stack (62) of this variation will be described with reference to FIG. 16. FIG. 16 shows the second plate stack (62) of the first embodiment that employs this variation. Regarding the second plate stack (62) of this variation, the following description will focus on the difference from the second plate stack (62) of the first embodiment.
  • FIG. 16 shows the cross section of part of the second plate stack (62) that is connected to the heat transfer tubes (50) of the first heat exchange portion (46). In FIG. 16, the 16A-16A cross section and the 16B-16B cross section are the cross sections taken along the cut lines shown in the 16C-16C cross section and the 16D-16D cross section. The 16C-16C cross section and the 16D-16D cross section are the cross sections taken along the cut lines shown in the 16A-16A cross section and the 16B-16B cross section.
  • The second plate stack (62) of this variation includes the base plate (70), the first plate (71), the second plate (72), and the third plate (73). The third plate (73) is a plate member (65). The third plate (73) is shaped into a flat plate similarly to the base plate (70), the first plate (71), and the second plate (72).
  • In the second plate stack (62), the base plate (70), the first plate (71), the second plate (72), and the third plate (73), each of which is close to the heat transfer tube (50) in this order, are disposed in the same order. The base plate (70) is joined to the first plate (71) by brazing; the first plate (71) is joined to the second plate (72) by brazing; and the second plate (72) is joined to the third plate (73) by brazing.
  • In the second plate stack (62) of this variation, the connection flow path (75) is formed by both the first plate (71) and the second plate (72). The third plate (73) covers the connection flow path (75) of the second plate (72) to seal the connection flow path (75).
  • Each of the first portion (80) and the second portion (85) of the connection flow path (75) is formed through both the first plate (71) and the second plate (72). The third portion (90) of the connection flow path (75) is formed in the second plate (72). The third portion (90) of this variation is formed in only the second plate (72) out of the first plate (71) and the second plate (72).
    • -Second Variation-
  • In each of the first to third embodiments, the width Wp1 of the first portion (80) forming the connection flow path (75) may be wider than the width Wt of the first heat transfer tube (51).
  • In each of the first to third embodiments, the width Wp2 of the second portion (85) forming the connection flow path (75) may be wider than the width Wt of the second heat transfer tube (52).
    • -Third Variation-
  • In each of the first to third embodiments, the first portion (80) forming the connection flow path (75) may overlap with part of the end surface of the first heat transfer tube (51). If the condition that "the first portion (80) communicates with all the inner flow paths (50a) formed in the first heat transfer tube (51)" is satisfied, part of the end surface of the first heat transfer tube (51) may be located outside the first portion (80).
    • -Fourth Variation-
  • In each of the first to third embodiments, the second portion (85) forming the connection flow path (75) may overlap with part of the end surface of the second heat transfer tube (52). If the condition that "the second portion (85) communicates with all the inner flow paths (50a) formed in the second heat transfer tube (52)" is satisfied, part of the end surface of the second heat transfer tube (52) may be located outside the second portion (85).
    • -Fifth Variation-
  • In the first or second embodiment, the connection flow path (75) may connect one first heat transfer tube (51) and one second heat transfer tube (52) adjacent to the second one (or the third one or above) of the first heat transfer tubes (51) that is located above and counted from the one first heat transfer tube (51).
  • In the first or second embodiment, the connection flow path (75) may connect one first heat transfer tube (51) and one second heat transfer tube (52) adjacent to the second one (or the third one or above) of the first heat transfer tubes (51) that is located below and counted from the one first heat transfer tube (51).
    • -Sixth Variation-
  • In each of the first to third embodiments, the outdoor heat exchanger (22) of the outdoor unit (20) may be the heat exchanger unit (40).
  • While the embodiments and variations thereof have been described above, it will be understood that various changes in form and details may be made without departing from the spirit and scope of the claims. The elements according to the embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other. In addition, the expressions of "first", "second", "third", . . . , in the specification and claims are used to distinguish the terms to which these expressions are given, and do not limit the number and order of the terms.
    • INDUSTRIAL APPLICABILITY
  • As described above, the present disclosure is useful for a heat exchanger unit, an air-conditioning indoor unit, and a refrigeration cycle apparatus.
    • DESCRIPTION OF REFERENCE CHARACTERS
    • 10
    Air Conditioner (Refrigeration Cycle Apparatus)
    11
    Refrigerant Circuit
    30
    Indoor Unit (Air-Conditioning Indoor Unit)
    40
    Heat Exchanger Unit
    50
    Heat Transfer Tube
    50a
    Inner Flow Path
    51
    First Heat Transfer Tube
    52
    Second Heat Transfer Tube
    53
    Fin
    56
    First Tube Line
    57
    Second Tube Line
    62
    Second Plate Stack (Plate Structure)
    65
    Plate Member
    71
    First Plate (First Plate Member)
    72
    Second Plate (Second Plate Member)
    75
    Connection Flow Path
    80
    First Portion
    81a
    First Long Side
    81b
    First Long Side
    CP1
    Center Point (of First Long Side)
    85
    Second Portion
    86a
    Second Long Side
    86b
    Second Long Side
    CP2
    Center Point (of Second Long Side)
    90
    Third Portion
    L1
    Center Line (of Connection Flow Path)

Claims (11)

  1. A heat exchanger unit (40) comprising a plurality of fins (53) and a plurality of heat transfer tubes (50) and configured to exchange heat between a heat medium flowing in the heat transfer tubes (50) and air,
    wherein
    each of the plurality of heat transfer tubes (50) is a flat tube in which a plurality of inner flow paths (50a) are formed,
    in each of the plurality of heat transfer tubes (50), the plurality of inner flow path (50a) are arranged in a line in a width direction of the heat transfer tube (50),
    the plurality of heat transfer tubes (50) include a plurality of first heat transfer tubes (51) and a plurality of second heat transfer tubes (52),
    the plurality of first heat transfer tubes (51) arranged in a line as well as being spaced apart from each other at intervals form a first tube row (56), and the plurality of second heat transfer tubes (52) arranged in a line as well as being spaced apart from each other at intervals form a second tube row (57),
    the first tube row (56) and the second tube row (57) are disposed in sequence from an upstream side to a downstream side of a flow of air that passes through the heat exchanger unit (40),
    the heat exchanger unit (40) includes a plate structure (62) which is joined to end portions of the plurality of heat transfer tubes (50) and in which a connection flow path (75) connecting one of the first heat transfer tubes (51) and one of the second heat transfer tubes (52) is formed,
    the connection flow path (75) has
    a first portion (80) facing an end surface of the first heat transfer tube (51) and communicating with all the inner flow paths (50a) formed in the first heat transfer tube (51),
    a second portion (85) facing an end surface of the second heat transfer tube (52) and communicating with all the inner flow paths (50a) formed in the second heat transfer tube (52), and
    a third portion (90) communicating with both the first portion (80) and the second portion (85),
    the first portion (80) has a pair of first long sides (81a, 81b) extending along a width direction of the first heat transfer tube (51),
    the second portion (85) has a pair of second long sides (86a, 86b) extending along a width direction of the second heat transfer tube (52),
    one end of the third portion (90) is connected to only one of the pair of first long sides (81a, 81b) of the first portion (80), and
    the other end of the third portion (90) is connected to only one of the pair of second long sides (86a, 86b) of the second portion (85).
  2. The heat exchanger unit of claim 1, wherein
    the plate structure (62) has a plurality of plate members (65) stacked and joined to each other, and
    the first portion (80), the second portion (85), and the third portion (90) of the connection flow path (75) are formed in one of the plate members (65).
  3. The heat exchanger unit of claim 1, wherein
    the plate structure (62) has a plurality of plate members (65) stacked and joined to each other,
    the plurality of plate members (65) include a first plate member (71) and a second plate member (72) that is located on the opposite side of the heat transfer tubes (50) with respect to the first plate member (71),
    the first portion (80) and the second portion (85) of the connection flow path (75) are formed through both the first plate member (71) and the second plate member (72), and
    the third portion (90) of the connection flow path (75) is formed in only the second plate member (72) out of the first plate member (71) and the second plate member (72).
  4. The heat exchanger unit of any one of claims 1 to 3, wherein
    a width of the first portion (80) is greater than equal to a width of the first heat transfer tube (51),
    a width of the second portion (85) is greater than equal to a width of the second heat transfer tube (52), and
    a width of the third portion (90) is less than or equal to the width of the first heat transfer tube (51) and less than or equal to the width of the second heat transfer tube (52).
  5. The heat exchanger unit of any one of claims 1 to 4, wherein
    the first long side (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the same side as the second long side (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected.
  6. The heat exchanger unit of claim 5, wherein
    the third portion (90) has a straight portion (94) that is positioned so as to face the first long side (81a, 81b) and the second long side (86a, 86b).
  7. The heat exchanger unit of any one of claims 1 to 4, wherein
    the first long side (81a, 81b) of the first portion (80) to which one end of the third portion (90) is connected is located on the opposite side of the second long side (86a, 86b) of the second portion (85) to which the other end of the third portion (90) is connected.
  8. The heat exchanger unit of claim 7, wherein
    a center line (L1) of the connection flow path (75) in a width direction is located above a straight line (L2) that connects a center point (CP1) of the first long side (81a, 81b) to which one end of the third portion (90) is connected and a center point (CP2) of the second long side (86a, 86b) to which the other end of the third portion (90) is connected.
  9. The heat exchanger unit of any one of claims 1 to 4, wherein
    one end of the third portion (90) is connected to part of the first long side (81a, 81b) that includes the center point (CP1) of the first long side (81a, 81b), and
    the other end of the third portion (90) is connected to part of the second long side (86a, 86b) that includes the center point (CP2) of the second long side (86a, 86b).
  10. An air-conditioning indoor unit comprising:
    the heat exchanger unit (40) of any one of claims 1 to 9,
    wherein
    the heat exchanger unit (40) exchanges heat between the heat medium and indoor air.
  11. A refrigeration cycle apparatus comprising:
    a refrigerant circuit (11) having the heat exchanger unit (40) of any one of claims 1 to 9,
    wherein
    the refrigerant circuit (11) circulates a refrigerant to perform a refrigeration cycle.
EP25817402.8A 2024-09-30 2025-04-14 Heat exchanger unit, air conditioning indoor equipment, and refrigeration cycle device Pending EP4779247A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2024170831A JP7719410B1 (en) 2024-09-30 2024-09-30 Heat exchanger unit, air conditioning indoor unit, and refrigeration cycle device
PCT/JP2025/014643 WO2026069792A1 (en) 2024-09-30 2025-04-14 Heat exchanger unit, air conditioning indoor equipment, and refrigeration cycle device

Publications (1)

Publication Number Publication Date
EP4779247A1 true EP4779247A1 (en) 2026-07-22

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EP (1) EP4779247A1 (en)
JP (1) JP7719410B1 (en)
WO (1) WO2026069792A1 (en)

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JP2005326135A (en) * 2004-04-12 2005-11-24 Showa Denko Kk Heat exchanger
JP2020016390A (en) * 2018-07-25 2020-01-30 ダイキン工業株式会社 Heat exchanger
CN114341587B (en) 2019-12-24 2025-07-04 日本开利株式会社 Heat exchanger and refrigeration cycle device
CN117203482A (en) * 2021-04-27 2023-12-08 东芝开利株式会社 Heat exchangers and refrigeration cycle devices
CN120077242A (en) * 2023-01-18 2025-05-30 日本开利株式会社 Heat exchanger and refrigeration cycle device

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