Heat exchanger and refrigeration cycle device

Abstract

This heat exchanger comprises a first heat exchanging body including a plurality of first flat tubes disposed spaced apart from one another in a first direction and having a tube axial direction extending in a second direction intersecting the first direction, a first refrigerant distributor into which one end portion of each of the plurality of first flat tubes is inserted, and a second refrigerant distributor into which the other end of each of the first flat tubes is inserted, wherein: the first refrigerant distributor includes a first outer tube which is disposed extending in the first direction and into which said one end portion of each of the plurality of first flat tubes is inserted, a first inner tube which is disposed extending in the first direction, is arranged inside the first outer tube, and which includes a plurality of first refrigerant outflow holes arranged spaced apart from one another in the first direction, and a first dividing plate which is joined to an inner wall of the first outer tube with the first inner tube penetrating through in a plate thickness; and the second refrigerant distributor includes a second outer tube which is disposed extending in the first direction and into which said other end portion of each of the plurality of first flat tubes is inserted, a second inner tube which is disposed extending in the first direction, is arranged inside the second outer tube, and which includes a plurality of second refrigerant outflow holes arranged spaced apart from one another in the first direction, and a second dividing plate which is joined to an inner wall of the second outer tube with the second inner tube penetrating through in a plate thickness.

Description

[Technical Field]

[0001] The present disclosure relates to a heat exchanger and a refrigeration cycle device having a plurality of flat tubes. [Background technology]

[0002] Some conventional refrigeration cycle devices have multiple heat exchangers, each consisting of one or more heat exchangers (see, for example, Patent Document 1). In each of the multiple sets, the heat exchanger is an air heat exchanger, and has an upper header pipe, a lower header pipe, heat transfer pipes, and fins.

[0003] During cooling operation, the sets are connected in series to form a series refrigerant flow path through which the refrigerant flows in series between the sets. In the series refrigerant flow path, the refrigerant flows from top to bottom through the heat transfer tubes of all the heat exchangers.

[0004] During heating operation, the groups are connected in parallel to form a parallel refrigerant flow path through which the refrigerant flows in parallel to each group. In the parallel refrigerant flow path, the refrigerant flows from bottom to top through the heat transfer tubes of all the heat exchangers.

[0005] Furthermore, in conventional heat exchangers, for example, a refrigerant distributor with a double-pipe structure including an inner pipe and an outer pipe is used as a lower header pipe. A plurality of outer pipes are provided, and a gap is formed between adjacent outer pipes among the plurality of outer pipes. One inner pipe is provided in succession with respect to the plurality of outer pipes. A plurality of heat transfer pipes are connected to the outer pipe in the pipe axis direction of the outer pipe, and the refrigerant that flows between the inner pipe and the outer pipe is distributed to the plurality of heat transfer pipes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2019 / 008664 Summary of the Invention [Problem to be solved by the invention]

[0007] Generally, when a heat exchanger functions as an evaporator, a two-phase refrigerant, consisting of a mixture of gas and liquid refrigerants, flows into the heat exchanger. In this case, a double-pipe refrigerant distributor consisting of an inner pipe and an outer pipe is sometimes used as the refrigerant distributor on the inlet side of the heat exchanger. In a double-pipe refrigerant distributor, a large number of refrigerant outlet holes are arranged side by side in the inner pipe. A double-pipe refrigerant distributor can evenly distribute refrigerant to the multiple heat transfer pipes that make up the heat exchanger while reducing the volume of the refrigerant distributor.

[0008] A refrigerant distributor with a single pipe structure is provided on the outlet side of the heat exchanger functioning as an evaporator. The refrigerant distributor distributes the refrigerant to the multiple heat transfer pipes that make up the heat exchanger when the heat exchanger functions as a condenser.

[0009] However, as in Patent Document 1, when multiple heat exchangers are installed in a single outdoor unit, the connection state of the multiple heat exchangers can be classified as either forming a serial refrigerant flow path or forming a parallel refrigerant flow path. When the multiple heat exchangers installed in the outdoor unit function as condensers for cooling operation and form a serial refrigerant flow path, the state of the refrigerant flowing into the upstream heat exchanger and the downstream heat exchanger of the flow path is different. That is, a gas refrigerant flows into the upstream heat exchanger in a single phase. On the other hand, a downstream heat exchanger flows into a gas-liquid two-phase refrigerant, in which a portion of the gas refrigerant condenses during heat exchange in the upstream heat exchanger. However, in this case, the refrigerant distributor on the inlet side of the downstream heat exchanger has a single-tube structure. Therefore, the refrigerant flowing into the downstream heat exchanger is not evenly distributed to the multiple flat tubes that make up the heat exchanger. In heat exchangers located downstream, the amount of refrigerant distributed is uneven depending on the position of the flat tubes, resulting in an insufficient amount of heat exchange near the flat tubes where a large amount of refrigerant is distributed, and an excessive amount of heat exchange near the flat tubes where a small amount of refrigerant is distributed, resulting in reduced heat exchange efficiency.

[0010] The present disclosure has been made to solve such problems, and aims to provide a heat exchanger and a refrigeration cycle device, which is one of multiple heat exchangers that functions as a condenser during cooling operation, and is equipped with a refrigerant distributor that can distribute refrigerant evenly to multiple flat tubes even when the heat exchangers are connected in series to form a series refrigerant flow path and are positioned downstream in the direction of refrigerant flow. [Means for solving the problem]

[0011] A heat exchanger according to the present disclosure includes a first heat exchange element having a plurality of first flat tubes arranged at intervals in a first direction and extending in a tube axis direction in a second direction intersecting the first direction, a first refrigerant distributor into which one ends of the plurality of first flat tubes are inserted, and a second refrigerant distributor into which the other ends of the plurality of first flat tubes are inserted, wherein the first refrigerant distributor is provided with a first outer tube extending in the first direction and into which the one ends of the plurality of first flat tubes are inserted, and a second refrigerant distributor extending in the first direction and disposed inside the first outer tube and arranged at intervals in the first direction. the second refrigerant distributor comprises a first inner pipe having a plurality of first refrigerant outlet holes spaced apart from one another in the first direction, and a first partition plate joined to an inner wall of the first outer pipe with the first inner pipe penetrating through a plate thickness; the second refrigerant distributor comprises a second outer pipe extending in the first direction and into which the other ends of the plurality of first flat tubes are inserted, a second inner pipe extending in the first direction, disposed inside the second outer pipe, and having a plurality of second refrigerant outlet holes spaced apart from one another in the first direction, and a second partition plate joined to an inner wall of the second outer pipe with the second inner pipe penetrating through a plate thickness. The refrigerant distributor includes a first heat exchanger, a second heat exchange element having a plurality of second flat tubes arranged at intervals in a third direction and having a tube axis direction extending in the second direction intersecting the third direction, a third refrigerant distributor into which one ends of the plurality of second flat tubes are inserted, and a fourth refrigerant distributor into which the other ends of the plurality of second flat tubes are inserted, wherein the third refrigerant distributor extends in the third direction and has a third outer tube into which the one ends of the plurality of second flat tubes are inserted, and the fourth refrigerant distributor extends in the third direction and has a third outer tube into which the other ends of the plurality of second flat tubes are inserted. a fourth outer pipe; a fourth inner pipe extending in the third direction, disposed inside the fourth outer pipe, and having a plurality of fourth refrigerant outlet holes spaced apart from one another in the third direction; and a fourth partition plate joined to an inner wall of the fourth outer pipe with the fourth inner pipe penetrating a plate thickness thereof, wherein when the first heat exchanger functions as a condenser, the first heat exchanger is connected in series to the second heat exchanger functioning as a condenser, and the second heat exchanger is disposed upstream of the first heat exchanger in a refrigerant flow direction. the first flat tubes include a downwind-side first flat tube arranged on the downwind side in the air flow direction and having the one end of the first flat tube, and an upwind-side first flat tube arranged on the upwind side in the air flow direction and having the other end of the first flat tube; the second flat tubes include a downwind-side second flat tube arranged on the downwind side in the air flow direction and having the one end of the second flat tube, and an upwind-side second flat tube arranged on the upwind side in the air flow direction and having the other end of the second flat tube; and the first refrigerant distributor and the second refrigerant distributor have specifications that differ in at least one of the diameters or numbers of the plurality of first refrigerant outlet holes and the plurality of second refrigerant outlet holes, the arrangement intervals or arrangement positions of the plurality of first refrigerant outlet holes and the plurality of second refrigerant outlet holes, the diameters of the first inner pipe and the second inner pipe, and the diameters of the first outer pipe and the second outer pipe. is.

[0012] The refrigeration cycle apparatus according to the present disclosure is a refrigeration cycle apparatus including an outdoor unit, No. 1 heat exchanger and a second heat exchanger; No. 1 a refrigerant pipe connecting the heat exchanger and the second heat exchanger; No. 1 a box-shaped housing that houses the heat exchanger and the second heat exchanger inside; and a rotating device disposed on top of the housing that forms an air flow by rotating; No. 1 a blower that blows the air that has passed through the heat exchanger and the second heat exchanger upward from the upper surface of the housing, No. 1 The heat exchanger and the second heat exchanger are arranged along some or all of the four side surfaces of the housing. [Effects of the Invention]

[0013] In the heat exchanger and refrigeration cycle apparatus according to the present disclosure, the refrigerant distributor has a double-pipe structure, and the inner pipe of the refrigerant distributor has multiple refrigerant outlet holes arranged side by side. Therefore, even when the refrigerant flows into the heat exchanger in a gas-liquid two-phase state, the refrigerant distributor can prevent uneven distribution of the refrigerant among the flat tubes. Furthermore, by evenly distributing the refrigerant among the flat tubes, the required heat exchange amount is uniform across the entire surface of the heat exchange element, preventing a decrease in heat exchange efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a refrigerant circuit diagram showing the configuration of a refrigeration cycle device 100 according to a first embodiment. [Figure 2] 1 is a perspective view showing a connection state between an outdoor heat exchanger 3 and an outdoor heat exchanger 4 in a refrigeration cycle apparatus 100 according to Embodiment 1. FIG. [Figure 3] 3 is a cross-sectional view showing the configuration of the outdoor heat exchanger 3 shown in FIG. 2. [Figure 4] 3 is a cross-sectional view showing the configuration of the outdoor heat exchanger 4 shown in FIG. 2. [Figure 5]4 is a cross-sectional view showing the configuration of a refrigerant distributor 31 provided in the outdoor heat exchanger 3 shown in FIG. [Figure 6] 4 is a cross-sectional view showing the configuration of a refrigerant distributor 32 provided in the outdoor heat exchanger 3 shown in FIG. [Figure 7] 5 is a cross-sectional view showing the configuration of a refrigerant distributor 41 provided in the outdoor heat exchanger 4 shown in FIG. [Figure 8] 5 is a cross-sectional view showing the configuration of a refrigerant distributor 42 provided in the outdoor heat exchanger 4 shown in FIG. [Figure 9] 1 is a perspective view showing a connection state between an outdoor heat exchanger 3 and an outdoor heat exchanger 4 in a heating operation state in a refrigeration cycle apparatus 100 according to Embodiment 1. FIG. [Figure 10] 3 is a diagram schematically showing a refrigerant distribution operation in a refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to the first embodiment. FIG. [Figure 11] 3 is a diagram schematically showing a refrigerant distribution operation in refrigerant distributors 32, 41, and 42 provided in the refrigeration cycle apparatus 100 according to the first embodiment. FIG. [Figure 12] 3 is a diagram schematically showing the state of a liquid refrigerant in a refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to the first embodiment. FIG. [Figure 13] 3 is a diagram schematically showing the state of liquid refrigerant in refrigerant distributors 32, 41, and 42 provided in the refrigeration cycle apparatus 100 according to the first embodiment. FIG. [Figure 14] 1 is a refrigerant circuit diagram showing a configuration of a refrigeration cycle device 100 according to a first modification of the first embodiment. [Figure 15] 1 is a refrigerant circuit diagram showing a configuration of a refrigeration cycle device 100 according to a first modification of the first embodiment. [Figure 16] 1 is a refrigerant circuit diagram showing a configuration of a refrigeration cycle device 100 according to a second modification of the first embodiment. [Figure 17] 10 is a diagram showing the flow of refrigerant when the refrigeration cycle apparatus 100 according to the second modification of the first embodiment is in a cooling operation state. FIG. [Figure 18]10 shows the flow of refrigerant when the refrigeration cycle apparatus 100 according to the second modification of the first embodiment is in a heating operation state. [Figure 19] 10 is a perspective view showing a connection state of an outdoor heat exchanger 3C and an outdoor heat exchanger 4C in a refrigeration cycle apparatus 100 according to a second embodiment. FIG. [Figure 20] FIG. 10 is a perspective view showing the appearance of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to a third embodiment. [Figure 21] 10 is a plan view schematically showing an example of the configuration of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to a third embodiment. FIG. [Figure 22] FIG. 10 is a perspective view showing the appearance of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to a modified example of the third embodiment. [Figure 23] 10 is a plan view schematically showing an example of the configuration of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to a third embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of a heat exchanger and a refrigeration cycle apparatus according to the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure. Furthermore, the present disclosure includes all possible combinations of configurations shown in the following embodiments and their modifications. In each drawing, identical or corresponding parts are designated by the same reference numerals, and their descriptions are omitted or simplified as appropriate. Furthermore, when multiple devices of the same type are distinguished by a subscript (capital letter at the end of the reference numeral), the subscript may be omitted if there is no need to distinguish or identify them. Note that the relative dimensions, shapes, etc. of each component in each drawing may differ from those in the actual device. The shape, size, and arrangement of the components shown in each drawing may be changed as appropriate within the scope of the present disclosure.

[0016] In each figure, the width direction of each outdoor heat exchanger is called the X direction, the height direction is called the Z direction, and the depth direction is called the Y direction. The X and Y directions are, for example, horizontal directions. The Z direction is, for example, the up-down direction, and may be vertical. The X direction is the stacking direction of multiple flat tubes. The Z direction is the axial direction of the flat tubes, and is the direction in which the refrigerant flows. The Y direction is the direction in which air flows. The X direction is sometimes called the "first direction" or "third direction." The Z direction is sometimes called the "second direction."

[0017] Embodiment 1 <Configuration of Refrigeration Cycle Apparatus 100> FIG. 1 is a refrigerant circuit diagram showing the configuration of a refrigeration cycle apparatus 100 according to a first embodiment. The refrigeration cycle apparatus 100 has an outdoor unit 101 and an indoor unit 201, and the outdoor unit 101 and the indoor unit 201 are connected by a refrigerant piping 310 to form a refrigeration cycle. The refrigerant piping 310 includes a plurality of refrigerant pipings 300-308. Here, when these refrigerant pipings 300-308 are collectively referred to as the refrigerant piping 310, the outdoor unit 101 and the indoor unit 201 are connected by connection ports P1 and P2. Both the connection port P1 and the connection port P2 are formed by the refrigerant piping 310. The connection port P1 is the connection port on the inflow side to the outdoor unit 101 when the refrigeration cycle apparatus 100 is in a cooling operation state, and is the connection port on the outflow side from the outdoor unit 101 when the refrigeration cycle apparatus 100 is in a heating operation state. The connection port P2 is an outlet connection port from the outdoor unit 101 when the refrigeration cycle apparatus 100 is in cooling operation, and an inlet connection port to the outdoor unit 101 when the refrigeration cycle apparatus 100 is in heating operation. In the first embodiment, one outdoor unit 101 and one indoor unit 201 are installed, but the number of outdoor units 101 and the number of indoor units 201 are not limited to one, and there may be more than one of each.

[0018] In the refrigerant circuit constituting the refrigeration cycle apparatus 100, for example, a chlorofluorocarbon refrigerant or an HFO refrigerant is sealed as a refrigerant.

[0019] Examples of fluorocarbon refrigerants include HFC (fluorinated hydrocarbon, hydrofluorocarbon) refrigerants. Examples of HFC refrigerants include difluoromethane (HFC-32, R32), pentafluoroethane (HFC-125, R125), 1,1,1-trifluoroethane (HFC-143a, R143a), and 1,1,1,2-tetrafluoroethane (HFC-134a, R134a). Other examples of fluorocarbon refrigerants include mixed refrigerants obtained by mixing the above HFC refrigerants. Examples of mixed refrigerants include "R410A," a mixed refrigerant of R32 and R125; "R407C," a mixed refrigerant of R32, R125, and R134a; and "R404A," a mixed refrigerant of R125, R143a, and R134a.

[0020] Examples of HFO (hydrofluoroolefin) refrigerants include HFO-1234yf, HFO-1234ze(E), and HFO-1234ze(Z).

[0021] The refrigerant sealed in the refrigerant circuit constituting the refrigeration cycle apparatus 100 is not limited to the above examples, and refrigerants used in vapor compression heat pumps can be used. Specifically, CO refrigerant, HC refrigerant (e.g., propane or isobutane refrigerant), ammonia refrigerant, etc. can be used as the refrigerant. Furthermore, a mixed refrigerant of a fluorocarbon refrigerant and an HFO refrigerant, such as a mixed refrigerant of R32 and HFO-1234yf, can also be used as the refrigerant.

[0022] (Outdoor unit 101) The outdoor unit 101 has a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an outdoor heat exchanger 4, an expansion valve 5, an expansion valve 6, a solenoid valve 7, a solenoid valve 8, two outdoor fans 9, an accumulator 10, and refrigerant piping 300-306 that connects these components.

[0023] The compressor 1 is a fluid machine that compresses the sucked low-pressure refrigerant and discharges it as a high-pressure refrigerant. The compressor 1 is configured as, for example, a rotary compressor or a scroll compressor. The compressor 1 may be configured as, for example, a compressor with a fixed rotational frequency, or as a compressor equipped with an inverter whose rotational frequency is controllable.

[0024] The four-way valve 2 is provided on the discharge side of the compressor 1 and is a flow path switching device for switching the refrigerant circulation direction between cooling operation and heating operation. The four-way valve 2 has four connection ports 2a to 2d that are connected to the compressor 1, the outdoor heat exchanger 3, the accumulator 10, and a connection port P1 that connects the outdoor unit 101 and the indoor unit 201. Of the four connection ports 2a to 2d of the four-way valve 2, the connection port 2a on the compressor 1 side is selected and connected to either the connection port 2b on the outdoor heat exchanger 3 side or the connection port 2d on the connection port P2 side of the outdoor unit 101. The other connection port of the connection ports 2b and 2d that is not selected is connected to the connection port 2c that is connected to the accumulator 10. Specifically, during cooling operation, the connection port 2a is connected to the connection port 2b, and the connection port 2d is connected to the connection port 2c. In the heating operation state, the connection port 2a is connected to the connection port 2d, and the connection port 2b is connected to the connection port 2c.

[0025] The outdoor heat exchanger 3 is a heat exchanger capable of exchanging heat between the refrigerant flowing therein and the air. The outdoor heat exchanger 3 functions as a condenser during cooling operation and as an evaporator during heating operation. The outdoor heat exchanger 3 is connected to the four-way valve 2 via refrigerant piping 300, which branches into refrigerant piping 301 between the outdoor heat exchanger 3 and the four-way valve 2. The refrigerant piping 301 is connected to the solenoid valve 8. The outdoor heat exchanger 3 has connection ports 3a and 3b connected to the refrigerant piping. Connection port 3a is connected to the four-way valve 2. Connection port 3b, on the opposite side of the outdoor heat exchanger 3, passes through the interior of the outdoor heat exchanger 3 and is connected to the expansion valve 5 via refrigerant piping 302. The refrigerant piping 302 branches into refrigerant piping 303 between the outdoor heat exchanger 3 and the expansion valve 5. The refrigerant piping 303 is connected to the solenoid valve 7. When wind generated by the outdoor blower 9 passes through the outdoor heat exchanger 3, heat is exchanged between the passing air and the refrigerant flowing inside. The outdoor blower 9 is configured as, for example, a centrifugal fan such as a sirocco fan or a turbo fan, a cross-flow fan, a mixed-flow fan, or a propeller fan. The outdoor heat exchanger 3 corresponds to the "second heat exchanger" in the first embodiment.

[0026] The outdoor heat exchanger 4 is a heat exchanger capable of exchanging heat between the refrigerant flowing therein and the air. The outdoor heat exchanger 4 functions as a condenser during cooling operation and as an evaporator during heating operation. The outdoor heat exchanger 4 is connected to the solenoid valve 8 via a refrigerant pipe 301. The refrigerant pipe 301 branches into the refrigerant pipe 303 between the outdoor heat exchanger 4 and the solenoid valve 8. The outdoor heat exchanger 4 has connection ports 4a and 4b connected to the refrigerant pipes. The connection port 4a is connected to the four-way valve 2 via the solenoid valve 8. The connection port 4b on the opposite side of the connection port 4a, passing through the interior, is connected to the expansion valve 6 via a refrigerant pipe 304. When wind generated by the outdoor blower 9 passes through the outdoor heat exchanger 4, heat is exchanged between the passing air and the refrigerant flowing therein. The outdoor heat exchanger 4 corresponds to the "heat exchanger" in the first embodiment. Refrigerant pipe 304 equipped with expansion valve 6 joins with refrigerant pipe 302 equipped with expansion valve 5. The joining point of refrigerant pipe 304 and refrigerant pipe 302 is connected to connection port P2. Connection port P2 serves as the outlet port from outdoor unit 101 in cooling operation and as the inlet port to outdoor unit 101 in heating operation.

[0027] The expansion valves 5 and 6 function as pressure reducing valves or expansion valves, and reduce the pressure of the refrigerant to expand it. The expansion valves 5 and 6 are configured as pressure reducing devices such as linear electronic expansion valves whose opening can be adjusted in multiple stages or continuously.

[0028] The solenoid valves 7 and 8 have the function of opening and closing the flow path depending on whether or not a voltage is applied, and cut off and open the flow of the refrigerant, thereby switching the flow path of the refrigerant.

[0029] The accumulator 10 is provided such that its outflow side is connected to the suction side of the compressor 1. The accumulator 10 has the function of separating liquid refrigerant from gas refrigerant and the function of storing excess refrigerant. The inflow side of the accumulator 10 is connected to the connection port 2c of the four-way valve 2 by a refrigerant pipe 306.

[0030] The outdoor unit 101 is provided with a control unit 11. The control unit 11 controls the operations of the compressor 1, the four-way valve 2, the expansion valve 5, the expansion valve 6, the solenoid valve 7, the solenoid valve 8, and the two outdoor fans 9.

[0031] The hardware configuration of the control unit 11 will be described. The control unit 11 is composed of a processing circuit. The processing circuit is composed of dedicated hardware or a processor. The dedicated hardware is, for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The processor executes programs stored in memory. The control unit 11 has a storage unit (not shown). The storage unit is composed of memory. The memory is a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, or EPROM (Erasable Programmable ROM), or a disk such as a magnetic disk, flexible disk, or optical disk.

[0032] (Indoor unit 201) The indoor unit 201 is composed of an indoor heat exchanger 21, an indoor blower 22, an expansion valve 23, and refrigerant pipes 307 and 308 that connect these components. The indoor unit 201, together with the outdoor unit 101, constitutes a refrigeration cycle. The indoor unit 201 supplies cold or hot heat from the outdoor unit 101 to a cooling load or a heating load. The refrigerant load and the heating load are, for example, the indoor space in which the indoor unit 201 is installed.

[0033] The indoor heat exchanger 21 is a heat exchanger capable of exchanging heat between the refrigerant flowing therein and the air. The indoor heat exchanger 21 functions as an evaporator during cooling operation and as a condenser during heating operation. The indoor heat exchanger 21 has connection ports 21a and 21b connected to refrigerant piping. Connection port 21a is connected to the expansion valve 23 via refrigerant piping 307. Connection port 21b, located on the opposite side of the interior from connection port 21a, is connected to connection port P1 via refrigerant piping 308. When air generated by the indoor blower 22 passes through the indoor heat exchanger 21, heat is exchanged between the air passing through and the refrigerant flowing therein. The indoor blower 22 is configured as, for example, a centrifugal fan such as a sirocco fan or a turbofan, a crossflow fan, a mixed-flow fan, or a propeller fan.

[0034] The expansion valve 23 functions as a pressure reducing valve or an expansion valve, and reduces the pressure of the refrigerant to expand it. The expansion valve 23 is configured as a pressure reducing device such as a linear electronic expansion valve whose opening can be adjusted in multiple stages or continuously.

[0035] <Operation of the refrigeration cycle device 100> <Cooling operation state (serial refrigerant flow path)> When the refrigeration cycle apparatus 100 is in a cooling operation state, the control unit 11 controls the expansion valve 5 to be fully closed, the solenoid valve 7 to be open, the solenoid valve 8 to be closed, and the expansion valve 6 to be fully open. The compressor 1 draws refrigerant from the accumulator 10 and compresses the refrigerant. The compressed refrigerant becomes gas refrigerant, is discharged from the compressor 1, and flows into the outdoor heat exchanger 3 via the four-way valve 2. As a result of a portion of the gas refrigerant condensing in the outdoor heat exchanger 3, the gas refrigerant becomes a two-phase gas-liquid refrigerant consisting of gas refrigerant and liquid refrigerant. The two-phase gas-liquid refrigerant passes through the solenoid valve 7 and flows into the outdoor heat exchanger 4. The refrigerant condensed in the outdoor heat exchanger 4 becomes liquid refrigerant. The liquid refrigerant passes through the expansion valve 6, flows out of the outdoor unit 101, and flows into the indoor unit 201. In the indoor unit 201, the refrigerant is decompressed by the expansion valve 23, and then evaporates in the indoor heat exchanger 21 to supply cold to the air. The refrigerant flows out of the indoor unit 201, flows into the outdoor unit 101, passes through refrigerant piping 305, and flows into the four-way valve 2. The refrigerant then flows out of the four-way valve 2, passes through refrigerant piping 306, and flows into the accumulator 10. The refrigerant is then sucked back into the compressor 1 from the accumulator 10, and circulates through the refrigerant circuit. This forms a refrigerant circuit having a refrigerant flow path in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series.

[0036] <Heating operation state (in case of serial refrigerant flow path)> When the refrigeration cycle apparatus 100 is in a heating operation state, the refrigerant flows in the opposite direction to that in the cooling operation state. Similar to the cooling operation state, the control unit 11 controls the expansion valve 5 to be fully closed, the solenoid valve 7 to be open, the solenoid valve 8 to be closed, and the expansion valve 6 to be fully open. The compressor 1 draws refrigerant from the accumulator 10 and compresses it. The compressed refrigerant becomes a gas refrigerant and is discharged from the compressor 1. It flows out of the outdoor unit 101 through the four-way valve 2 and into the indoor unit 201. In the indoor unit 201, heat exchange occurs in the indoor heat exchanger 21, where the refrigerant condenses. The refrigerant flows into the expansion valve 23 and is decompressed by the expansion valve 23. The refrigerant then flows out of the indoor unit 201 and into the outdoor unit 101. In the outdoor unit 101, the refrigerant flows into the outdoor heat exchanger 4 through the expansion valve 6 and evaporates through heat exchange. The refrigerant then passes through the solenoid valve 7 and flows into the outdoor heat exchanger 3. After further heat exchange in the outdoor heat exchanger 3, the refrigerant becomes gaseous refrigerant. The gaseous refrigerant flows into the four-way valve 2. The refrigerant then flows out of the four-way valve 2, passes through the refrigerant piping 306, and flows into the accumulator 10. The refrigerant is then sucked back into the compressor 1 from the accumulator 10, and circulates through the refrigerant circuit. This forms a refrigerant circuit having a refrigerant flow path in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series.

[0037] <Heating operation state (parallel refrigerant flow path)> In the above <Heating operation state (in the case of a serial refrigerant flow path)>, the case where the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series to form a serial refrigerant flow path has been described, but the present invention is not limited to this case. That is, the connection of the outdoor heat exchanger 3 and the outdoor heat exchanger 4 may be configured to be switchable between a serial refrigerant flow path and a parallel refrigerant flow path depending on the operating state of the refrigeration cycle apparatus 100. In addition, in the heating operation state, a parallel refrigerant flow path may be formed where the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in parallel. This case will be described later using Figures 14 and 15.

[0038] <Outdoor heat exchanger 3 and outdoor heat exchanger 4> FIG. 2 is a perspective view showing a connection state of the outdoor heat exchanger 3 and the outdoor heat exchanger 4 in the refrigeration cycle apparatus 100 according to the first embodiment. FIG. 2 shows the refrigeration cycle apparatus 100 in a cooling operation state. FIG. 2 shows a refrigerant flow path in which the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are connected in series, expressed by a simple connection using refrigerant piping. In FIG. 2, solid arrows indicate the direction of refrigerant flow, and hollow arrows indicate the direction of airflow generated by the outdoor blower 9 (i.e., the airflow direction). FIG. 3 is a cross-sectional view showing the configuration of the outdoor heat exchanger 3 shown in FIG. 2. FIG. 4 is a cross-sectional view showing the configuration of the outdoor heat exchanger 4 shown in FIG. 2.

[0039] <Configuration of outdoor heat exchanger 3> First, we will explain the configuration of the outdoor heat exchanger 3. As shown in Figures 2 and 3, the outdoor heat exchanger 3 is made up of a refrigerant distributor 31, a refrigerant distributor 32, a plurality of heat exchange elements 33, and a folded header 34. As shown in Figure 2, a refrigerant pipe 35 is connected to the refrigerant distributor 31, and a refrigerant pipe 36 is connected to the refrigerant distributor 32.

[0040] As shown in Fig. 3 , the multiple heat exchange elements 33 include heat exchange elements 33A and 33B. The heat exchange elements 33A and 33B are arranged side by side in the airflow direction and face each other. In other words, the two heat exchange elements 33A and 33B are arranged in layers along the direction of the airflow generated by the outdoor blower 9. Hereinafter, the heat exchange element 33 arranged on the upwind side will be referred to as heat exchange element 33B, and the heat exchange element 33 arranged on the downwind side will be referred to as heat exchange element 33A. Because the heat exchange elements 33A and 33B have basically the same configuration, they will be collectively referred to as heat exchange elements 33 below.

[0041] The heat exchange element 33 is composed of a plurality of flat tubes 37 and a plurality of fins 38. The plurality of flat tubes 37 are arranged side by side in the horizontal direction (i.e., the X direction) at intervals from one another. As a result, the wind generated by the outdoor blower 9 flows between adjacent flat tubes 37 in the direction of the white arrows in FIG. 2. The axial direction of the plurality of flat tubes 37 is the Z direction. The refrigerant flows in the Z direction within the flat tubes 37. As the refrigerant flows within the flat tubes 37, heat exchange occurs between the refrigerant and the air.

[0042] The fins 38 are arranged between adjacent flat tubes 37 in the X direction. The fins 38 are joined to the side surfaces of the adjacent flat tubes 37 and transfer heat to the flat tubes 37. The fins 38 improve the efficiency of heat exchange between the air and the refrigerant, and for example, corrugated fins are used. However, the fins 38 are not limited to corrugated fins and may be, for example, flat fins. Furthermore, because heat exchange between the air and the refrigerant occurs on the surfaces of the flat tubes 37, the fins 38 are not necessarily provided. When multiple heat exchange elements 33 have fins 38, the same fins 38 may be shared among these multiple heat exchange elements 33.

[0043] Fig. 5 is a cross-sectional view showing the configuration of a refrigerant distributor 31 provided in the outdoor heat exchanger 3 shown in Fig. 3. Fig. 6 is a cross-sectional view showing the configuration of a refrigerant distributor 32 provided in the outdoor heat exchanger 3 shown in Fig. 3.

[0044] As shown in FIG. 3, the flat tubes 37 of the heat exchange element 33A have tube end portions 37a and 37b at both ends in the tube axis direction. Of the tube end portions 37a and 37b, a refrigerant distributor 31 is provided below the lower tube end portion 37a. As shown in FIG. 5, the refrigerant distributor 31 is composed of an outer tube 51 and a connecting tube 52. The refrigerant distributor 31 has a single-tube structure. The outer tube 51 is composed of a circular tube, and the tube axis direction is the X direction. A plurality of flat tube insertion holes 51e are provided in the upper surface of the outer tube 51. The plurality of flat tube insertion holes 51e are arranged side by side in the X direction at intervals from one another. The plurality of flat tube insertion holes 51e are through-holes that penetrate the upper surface of the outer tube 51. The tube end portion 37a of each flat tube 37 is directly inserted into the flat tube insertion hole 51e of the outer tube 51. The outer tube 51 has tube end portions 51a and 51b at both ends in the X direction. Of the tube end portions 51a and 51b, a closing plate 51c is provided on the tube end portion 51a side, and a closing plate 51d is provided on the tube end portion 51b side. The tube end portions 51a and 51b are closed by the closing plates 51c and 51d, respectively, and are not open.

[0045] As shown in FIG. 5, the connecting pipe 52 is connected to the outer pipe 51. The pipe axis direction of the connecting pipe 52 is the Z direction. The lower end 52a of the connecting pipe 52 is inserted into the outer pipe 51. The internal space of the connecting pipe 52 and the internal space of the outer pipe 51 are in communication with each other. As described above, the refrigerant distributor 31 is connected to the refrigerant piping 35 as shown in FIG. 2. Specifically, the outer pipe 51 of the refrigerant distributor 31 is connected to the refrigerant piping 35 via the connecting pipe 52. As shown in FIG. 5, the interior of the refrigerant distributor 31 forms a single space consisting of the internal space of the connecting pipe 52 and the internal space of the outer pipe 51. The refrigerant that flows from the refrigerant piping 35 into the internal space of the refrigerant distributor 31 is directly distributed to the multiple flat tubes 37 of the heat exchange element 33A.

[0046] Here, outer pipe 51 is illustrated as a single cylinder with closing plates 51c and 51d at both ends, but the cross-sectional shape of outer pipe 51 does not have to be circular and may be rectangular or elliptical. Furthermore, outer pipe 51 does not have to be formed from a single cylindrical part. For example, outer pipe 51 may be divided into two halves: an upper half into which flat tube 37 is inserted and an opposite (i.e., lower) half, and outer pipe 51 may be formed by joining the upper and lower parts. The same applies to outer pipes 53, 57, and 61 described below.

[0047] Turn-back headers 34 are provided above the tube ends 37b of the flat tubes 37 of the heat exchange element 33A and above the tube ends 37b of the flat tubes 37 of the heat exchange element 33B. In this manner, the heat exchange element 33A is connected to the heat exchange element 33B via the turn-back headers 34. The turn-back headers 34 redirect the refrigerant flowing from the flat tubes 37 of the heat exchange element 33A to the flat tubes 37 of the heat exchange element 33B, thereby turning the refrigerant from a downward to an upward flow back to a downward flow. Specifically, the refrigerant flows from a downward to an upward direction in the Z direction in the flat tubes 37 of the heat exchange element 33A. On the other hand, the refrigerant flows from an upward to a downward direction in the flat tubes 37 of the heat exchange element 33B. In this manner, the turn-back headers 34 switch the refrigerant flow direction. Here, an example is shown in which the flat tubes 37 on the leeward side and the flat tubes 37 on the windward side are connected by the folded header 34, but the present invention is not limited to this case. The flat tubes 37 do not have to be separated into the upwind side and the downwind side, and may be composed of a single flat tube. A case in which the flat tube 37 is composed of a single flat tube will be described later in embodiment 2 using Figure 19.

[0048] As shown in FIG. 3, a refrigerant distributor 32 is provided below lower pipe ends 37a of the multiple flat tubes 37 of the heat exchange element 33B. As shown in FIG. 6, the refrigerant distributor 32 is composed of an outer pipe 53, an inner pipe 54, and a connecting pipe 56. The refrigerant distributor 32 has a double-pipe structure. The outer pipe 53 is composed of a circular pipe, and the pipe axis direction is the X direction. A plurality of flat tube insertion holes 53e are provided in the upper surface of the outer pipe 53. The multiple flat tube insertion holes 53e are arranged side by side in the X direction with intervals between them. The multiple flat tube insertion holes 53e are through-holes that penetrate the upper surface of the outer pipe 53. The pipe ends 37a of each flat tube 37 are directly inserted into the flat tube insertion holes 53e of the outer pipe 53. A closing plate 53c is provided on the tube end 53a side, and a closing plate 53d is provided on the tube end 53b side of the outer tube 53. The tube ends 53a and 53b are closed by the closing plates 53c and 53d, respectively, and are not open.

[0049] As shown in FIG. 6, the connecting pipe 56 is connected to the outer pipe 53. The pipe axis direction of the connecting pipe 56 is the Z direction. The lower end portion 56a of the connecting pipe 56 is inserted into the outer pipe 53. The internal space of the connecting pipe 56 and a first internal space 53g, which is the internal space on the pipe end portion 53a side of the outer pipe 53, are in communication with each other. The cross-sectional shape of the first internal space 53g is circular. As described above, the refrigerant distributor 32 is connected to the refrigerant piping 36 as shown in FIG. 2. Specifically, the outer pipe 53 of the refrigerant distributor 32 is connected to the refrigerant piping 36 via the connecting pipe 56.

[0050] The refrigerant distributor 32 has a double-pipe structure, with an inner pipe 54 disposed inside the outer pipe 53. A gap exists between an inner wall 53f of the outer pipe 53 and an outer wall 54f of the inner pipe 54, and this gap forms a second internal space 53h of the outer pipe 53. The cross-sectional shape of the second internal space 53h is donut-shaped (i.e., annular). The inner pipe 54 has a plurality of refrigerant outlet holes 54c arranged side by side on its side surface. The inner pipe 54 is joined to the outer pipe 53 via a partition plate 55. The partition plate 55 is disposed between the first internal space 53g of the outer pipe 53 and the closing plate 53d. The partition plate 55 separates the first internal space 53g from the second internal space 53h. A through-hole 55a is formed in the center of the partition plate 55. Of the pipe ends 54a and 54b of the inner pipe 54, the pipe end 54a is fitted into the through-hole 55a. The pipe end 54a opens toward the first internal space 53g. Therefore, the first internal space 53g and the internal space of the inner pipe 54 are in communication with each other. The pipe end 54b of the inner pipe 54 is joined to the closure plate 53d and is in a closed state. The outer periphery of the partition plate 55 is joined to the inner wall 53f of the outer pipe 53. As described above, the partition plate 55 is joined to the inner wall 53f of the outer pipe 53 and the outer wall 54f of the inner pipe 54. Therefore, the refrigerant flowing inside the refrigerant distributor 32 can pass between the first internal space 53g on the side of the pipe end 53a to which the connecting pipe 56 is connected and the closure plate 53d on the opposite side of the pipe end 53b only via the internal space of the inner pipe 54.

[0051] <Configuration of outdoor heat exchanger 4> Next, the configuration of the outdoor heat exchanger 4 will be described. As shown in Figures 2 and 4, the outdoor heat exchanger 4 is made up of a refrigerant distributor 41, a refrigerant distributor 42, a plurality of heat exchange elements 43, and a folded header 44. As shown in Figure 2, the refrigerant distributor 41 is connected to the refrigerant piping 36, and the refrigerant distributor 42 is connected to the refrigerant piping 45.

[0052] As shown in Fig. 4, the multiple heat exchange elements 43 include a heat exchange element 43A and a heat exchange element 43B. The heat exchange elements 43A and 43B are arranged side by side in the airflow direction and face each other. In other words, the two heat exchange elements 43A and 43B are arranged in layers along the direction of the airflow generated by the outdoor blower 9. Hereinafter, the heat exchange element 43 arranged on the upwind side will be referred to as heat exchange element 43B, and the heat exchange element 43 arranged on the downwind side will be referred to as heat exchange element 43A. Because the heat exchange elements 43A and 43B have basically the same configuration, they will be collectively referred to as heat exchange element 43 below.

[0053] The heat exchange element 43 is composed of a plurality of flat tubes 47 and a plurality of fins 48. The plurality of flat tubes 47 are arranged side by side in the horizontal direction (i.e., the X direction) at intervals from one another. As a result, the wind generated by the outdoor blower 9 flows between adjacent flat tubes 47 in the direction of the white arrows in FIG. 2. The axial direction of the plurality of flat tubes 47 is the Z direction. The refrigerant flows in the Z direction within the flat tubes 47. As the refrigerant flows within the flat tubes 47, heat exchange occurs between the refrigerant and the air.

[0054] The fins 48 are arranged between adjacent flat tubes 47 in the X direction. The fins 48 are joined to the side surfaces of the adjacent flat tubes 47 and transfer heat to the flat tubes 47. The fins 48 improve the heat exchange efficiency between the air and the refrigerant, and for example, corrugated fins are used. However, the fins 48 are not limited to corrugated fins and may be, for example, flat fins. Furthermore, because heat exchange between the air and the refrigerant occurs on the surfaces of the flat tubes 47, the fins 48 are not necessarily provided. When multiple heat exchange bodies 43 have fins 48, the same fins 48 may be shared among these multiple heat exchange bodies 43.

[0055] Fig. 7 is a cross-sectional view showing the configuration of a refrigerant distributor 41 provided in the outdoor heat exchanger 4 shown in Fig. 4. Fig. 8 is a cross-sectional view showing the configuration of a refrigerant distributor 42 provided in the outdoor heat exchanger 4 shown in Fig. 4.

[0056] As shown in FIG. 4, of the pipe ends 47a and 47b of the multiple flat tubes 47 of the heat exchange element 43A, a refrigerant distributor 41 is provided below the lower pipe end 47a. As shown in FIG. 7, the refrigerant distributor 41 is composed of an outer pipe 57, an inner pipe 58, and a connecting pipe 60. The refrigerant distributor 41 has a double-pipe structure. The outer pipe 57 is composed of a circular pipe, and the pipe axis direction is the X direction. A plurality of flat tube insertion holes 57e are provided in the upper surface of the outer pipe 57. The plurality of flat tube insertion holes 57e are arranged side by side in the X direction with intervals between them. The plurality of flat tube insertion holes 57e are through-holes that penetrate the upper surface of the outer pipe 57. The pipe end 47a of each flat tube 47 is directly inserted into the flat tube insertion hole 57e of the outer pipe 57. A closing plate 57c is provided on the tube end 57a side, and a closing plate 57d is provided on the tube end 57b side of the outer tube 57. The tube ends 57a and 57b are closed by the closing plates 57c and 57d, respectively, and are not open.

[0057] As shown in FIG. 7, the connecting pipe 60 is connected to the outer pipe 57. The pipe axis direction of the connecting pipe 60 is the Z direction. The lower end portion 60a of the connecting pipe 60 is inserted into the outer pipe 57. The internal space of the connecting pipe 60 and a first internal space 57g, which is the internal space on the pipe end portion 57a ​​side of the outer pipe 57, are in communication with each other. The cross-sectional shape of the first internal space 57g is circular. As described above, the refrigerant distributor 41 is connected to the refrigerant pipe 36 as shown in FIG. 2. Specifically, the outer pipe 57 of the refrigerant distributor 41 is connected to the refrigerant pipe 36 via the connecting pipe 60.

[0058] The refrigerant distributor 41 has a double-pipe structure, with an inner pipe 58 disposed inside an outer pipe 57. A gap exists between an inner wall 57f of the outer pipe 57 and an outer wall 58f of the inner pipe 58, and this gap forms a second internal space 57h of the outer pipe 57. The cross-sectional shape of the second internal space 57h is donut-shaped (i.e., annular). The inner pipe 58 has a plurality of refrigerant outlet holes 58c arranged side by side on its side surface. The inner diameter of the refrigerant outlet holes 58c may be the same as or different from the inner diameter of the refrigerant outlet hole 54c shown in FIG. 6 and the inner diameter of the refrigerant outlet hole 62c shown in FIG. 8. The inner pipe 58 is joined to the outer pipe 57 via a partition plate 59. The partition plate 59 is disposed between a first internal space 57g of the outer pipe 57 and the closing plate 57d. The partition plate 59 separates the first internal space 57g from the second internal space 57h. A through-hole 59a is formed in the center of the partition plate 59. Of the pipe ends 58a and 58b of the inner pipe 58, the pipe end 58a is fitted into the through-hole 59a. The pipe end 58a opens toward the first internal space 57g. Therefore, the first internal space 57g and the internal space of the inner pipe 58 are in communication with each other. The pipe end 58b of the inner pipe 58 is joined to the closure plate 57d and is in a closed state. The outer periphery of the partition plate 59 is joined to the inner wall 57f of the outer pipe 57. As described above, the partition plate 59 is joined to the inner wall 57f of the outer pipe 57 and the outer wall 58f of the inner pipe 58. Therefore, the refrigerant flowing inside the refrigerant distributor 41 can pass between the first internal space 57g on the pipe end 57a side to which the connecting pipe 60 is connected and the closure plate 57d on the opposite pipe end 58b side only through the internal space of the inner pipe 58.

[0059] Turn-back headers 44 are provided above the upper tube ends 47b of the flat tubes 47 of the heat exchange element 43A and above the upper tube ends 47b of the flat tubes 47 of the heat exchange element 43B. In this manner, the heat exchange element 43A is connected to the heat exchange element 43B via the turn-back headers 44. The turn-back headers 44 have the function of turning the refrigerant flowing from the flat tubes 47 of the heat exchange element 43A back to the flat tubes 47 of the heat exchange element 43B, thereby causing the refrigerant to flow from downward to upward and back to a downward flow. Specifically, the refrigerant flows from downward to upward in the Z direction in the flat tubes 47 of the heat exchange element 43A. On the other hand, the refrigerant flows from upward to downward in the Z direction in the flat tubes 47 of the heat exchange element 43B. In this manner, the turn-back headers 44 switch the refrigerant flow direction. Here, an example is shown in which the flat tubes 47 on the leeward side and the flat tubes 47 on the windward side are connected by the folded header 44, but the present invention is not limited to this case. The flat tubes 47 do not have to be separated into the upwind side and the downwind side, and may be composed of a single flat tube. A case in which the flat tube 47 is composed of a single flat tube will be described later in embodiment 2 using Figure 19.

[0060] As shown in FIG. 4, of the pipe ends 47a and 47b of the multiple flat tubes 47 of the heat exchange element 43B, a refrigerant distributor 42 is provided below the lower pipe end 47a. As shown in FIG. 8, the refrigerant distributor 42 is composed of an outer pipe 61, an inner pipe 62, and a connecting pipe 64. The refrigerant distributor 42 has a double-pipe structure. The outer pipe 61 is composed of a circular pipe, and the pipe axis direction is the X direction. A plurality of flat tube insertion holes 61e are provided in the upper surface of the outer pipe 61. The multiple flat tube insertion holes 61e are arranged side by side in the X direction with intervals between them. The multiple flat tube insertion holes 61e are through-holes that penetrate the upper surface of the outer pipe 61. The pipe end 47a of each flat tube 47 is directly inserted into the flat tube insertion hole 61e of the outer pipe 61. A closing plate 61c is provided on the tube end 61a side, and a closing plate 61d is provided on the tube end 61b side of the outer tube 61. The tube ends 61a and 61b are closed by the closing plates 61c and 61d, respectively, and are not open.

[0061] As shown in FIG. 8, the connecting pipe 64 is connected to the outer pipe 61. The pipe axis direction of the connecting pipe 64 is the Z direction. The lower end portion 64a of the connecting pipe 64 is inserted into the outer pipe 61. The internal space of the connecting pipe 64 and a first internal space 61g, which is the internal space on the pipe end portion 61a side of the outer pipe 61, are in communication with each other. The cross-sectional shape of the first internal space 61g is circular. As described above, the refrigerant distributor 42 is connected to the refrigerant piping 45 as shown in FIG. 2. Specifically, the outer pipe 61 of the refrigerant distributor 42 is connected to the refrigerant piping 45 via the connecting pipe 64.

[0062] The refrigerant distributor 42 has a double-pipe structure, with an inner pipe 62 disposed inside an outer pipe 61. A gap exists between an inner wall 61f of the outer pipe 61 and an outer wall 62f of the inner pipe 62, and this gap forms a second internal space 61h of the outer pipe 61. The cross-sectional shape of the second internal space 61h is donut-shaped (i.e., annular). The inner pipe 62 has a plurality of refrigerant outlet holes 62c arranged side by side on its side surface. The inner pipe 62 is joined to the outer pipe 61 via a partition plate 63. The partition plate 63 is disposed between the first internal space 61g of the outer pipe 61 and the closing plate 61d. The partition plate 63 separates the first internal space 61g from the second internal space 61h. A through-hole 63a is formed in the center of the partition plate 63. Of the pipe ends 62a and 62b of the inner pipe 62, the pipe end 62a is fitted into the through-hole 63a. The pipe end 62a opens toward the first internal space 61g. Therefore, the first internal space 61g and the internal space of the inner pipe 62 are in communication with each other. The pipe end 62b of the inner pipe 62 is joined to the closure plate 61d and is in a closed state. The outer periphery of the partition plate 63 is joined to the inner wall 61f of the outer pipe 61. As described above, the partition plate 63 is joined to the inner wall 61f of the outer pipe 61 and the outer wall 62f of the inner pipe 62. Therefore, the refrigerant flowing through the refrigerant distributor 42 can pass between the first internal space 61g on the side of the pipe end 61a to which the connecting pipe 64 is connected and the closure plate 61d on the opposite side of the pipe end 61b only via the internal space of the inner pipe 62.

[0063] 6, and each comprises outer pipes 57 and 61, inner pipes 58 and 62, partition plates 59 and 63, and connecting pipes 60 and 64. Refrigerant distributor 41 is connected to refrigerant piping 36 via connecting pipe 60, and refrigerant distributor 42 is connected to refrigerant piping 45 via connecting pipe 64.

[0064] The outdoor heat exchanger 4 may be referred to as the "heat exchanger." The heat exchange element 43 may be referred to as the "first heat exchange element." The flat tubes 47 may be referred to as the "first flat tube." Furthermore, the flat tubes 47 connected to the refrigerant distributor 41 may be referred to as the "downwind-side first flat tube," and the flat tubes 47 connected to the refrigerant distributor 42 may be referred to as the "upwind-side first flat tube." The refrigerant distributor 41 may be referred to as the "first refrigerant distributor," and the refrigerant distributor 42 may be referred to as the "second refrigerant distributor." Furthermore, the outer tube 57 may be referred to as the "first outer tube," the inner tube 58 as the "first inner tube," the refrigerant outlet hole 58c as the "first refrigerant outlet hole," and the partition plate 59 as the "first partition plate." Furthermore, the outer pipe 61 may be referred to as the "second outer pipe," the inner pipe 62 as the "second inner pipe," the refrigerant outlet hole 62c as the "second refrigerant outlet hole," and the partition plate 63 as the "second partition plate." Furthermore, the folded header 44 may be referred to as the "first folded header." Furthermore, the pipe end 47a of the flat tube 47 inserted into the refrigerant distributor 41 may be referred to as the "one end of the first flat tube," and the pipe end 47a of the flat tube 47 inserted into the refrigerant distributor 42 may be referred to as the "other end of the first flat tube."

[0065] The outdoor heat exchanger 3 may also be referred to as the "second heat exchanger." The heat exchange element 33 may also be referred to as the "second heat exchange element." The flat tubes 37 may also be referred to as the "second flat tube." The flat tubes 37 connected to the refrigerant distributor 31 may also be referred to as the "downwind-side second flat tube," and the flat tubes 37 connected to the refrigerant distributor 32 may also be referred to as the "upwind-side second flat tube." The refrigerant distributor 31 may also be referred to as the "third refrigerant distributor," and the refrigerant distributor 32 may also be referred to as the "fourth refrigerant distributor." The outer tube 51 may also be referred to as the "third outer tube." The outer tube 53 may also be referred to as the "fourth outer tube," the inner tube 54 may also be referred to as the "fourth inner tube," the refrigerant outlet hole 54c may also be referred to as the "fourth refrigerant outlet hole," and the partition plate 55 may also be referred to as the "fourth partition plate." The folded header 34 may also be referred to as the "second folded header." In addition, the tube end 37a of the flat tube 37 inserted into the refrigerant distributor 31 may be referred to as "one end of the second flat tube," and the tube end 37a of the flat tube 37 inserted into the refrigerant distributor 32 may be referred to as "the other end of the second flat tube."

[0066] <Refrigerant flow in outdoor heat exchanger 3 and outdoor heat exchanger 4> Next, the flow of refrigerant in the outdoor heat exchanger 3 and the outdoor heat exchanger 4 will be described.

[0067] <Refrigerant flow during cooling operation> First, the flow of refrigerant in cooling operation will be described. As described above, FIG. 2 is a perspective view illustrating the connection state between the outdoor heat exchanger 3 and the outdoor heat exchanger 4 and the flow of refrigerant in cooling operation. As shown in FIG. 2, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are provided with four connecting pipes, namely, connecting pipe 52, connecting pipe 56, connecting pipe 60, and connecting pipe 64. Of these, connecting pipe 56 and connecting pipe 60 are connected by refrigerant piping 36. Refrigerant flowing in from refrigerant piping 35 connected to connecting pipe 52 is partially condensed in the outdoor heat exchanger 3, becoming a two-phase gas-liquid state, and then flows out into refrigerant piping 36. The refrigerant then flows in this two-phase gas-liquid state into the outdoor heat exchanger 4. In the outdoor heat exchanger 4, the refrigerant first flows into the refrigerant distributor 41. The refrigerant distributor 41 has a double-pipe structure, and its inner pipe 58 is provided with a number of refrigerant outlet holes 58c. The refrigerant that has flowed into the refrigerant distributor 41 flows through the refrigerant outlet holes 58c into the second internal space 57h as it passes through the interior of the inner pipe 58. The refrigerant is then distributed from the second internal space 57h to the flat tubes 47. In this way, by providing the refrigerant outlet holes 58c in the inner pipe 58, the refrigerant is evenly distributed to the flat tubes 47 of the heat exchange element 43A. The refrigerant condensed inside the heat exchange elements 43A and 43B flows through the refrigerant distributor 42 into the refrigerant pipe 45.

[0068] As described above, during cooling operation, of the outdoor heat exchangers 3 and 4 that form a series refrigerant flow path, the refrigerant distributor 41 on the inlet side of the outdoor heat exchanger 4 located downstream has a double-pipe structure. The inner pipe 58 of the refrigerant distributor 41 has a large number of refrigerant outlet holes 58c arranged in parallel. This improves the uniformity of distribution of the gas-liquid two-phase refrigerant to the heat exchange element 43A in the outdoor heat exchanger 4 located downstream.

[0069] Specifically, in the refrigerant distributor 41, the refrigerant flows into the first internal space 57g of the outer pipe 57 via the connecting pipe 60. The refrigerant then temporarily enters the interior of the inner pipe 58 from the first internal space 57g and flows out from the numerous refrigerant outlet holes 58c arranged side by side in the inner pipe 58 into the second internal space 57h of the outer pipe 57. At this time, in the outer pipe 57, the second internal space 57h is separated from the first internal space 57g by a partition plate 59. Therefore, the refrigerant that has flowed into the second internal space 57h of the outer pipe 57 does not flow toward the first internal space 57g, but flows out into the multiple flat tubes 47 connected to the outer pipe 57 via the flat tube insertion holes 57e.

[0070] Here, the refrigerant distribution operation in the single-pipe structure and the double-pipe structure will be described. Fig. 10 is a diagram schematically showing the refrigerant distribution operation in the refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to the first embodiment. Fig. 11 is a diagram schematically showing the refrigerant distribution operation in the refrigerant distributors 32, 41, and 42 provided in the refrigeration cycle apparatus 100 according to the first embodiment. For ease of understanding, Figs. 10 and 11 show the case where the refrigerant outflow holes 54c, 58c, and 62c open directly downward.

[0071] 10, in the case of a single-pipe structure, the refrigerant flows in from one location (i.e., connecting pipe 52) and flows out from multiple locations (i.e., flat pipe insertion holes 51e). Therefore, the refrigerant tends to flow out more from flat pipe insertion holes 51e located closer to connecting pipe 52.

[0072] 11, in the case of a double-pipe structure, the refrigerant flows into the outer pipes 53, 57, 61 from multiple locations (i.e., refrigerant outlet holes 54c, 58c, 62c of the inner pipes 54, 58, 62) and flows out from multiple locations (i.e., flat pipe insertion holes 53e, 57e, 61e). Therefore, even if the outflow from the inner pipes 54, 58, 62 is uneven, the uniformity of the refrigerant distribution is improved compared to a case where the inner pipes 54, 58, 62 are not present.

[0073] Fig. 12 is a diagram schematically showing the state of liquid refrigerant in the refrigerant distributor 31 provided in the refrigeration cycle apparatus 100 according to embodiment 1. Fig. 13 is a diagram schematically showing the state of liquid refrigerant in the refrigerant distributors 32, 41, and 42 provided in the refrigeration cycle apparatus 100 according to embodiment 1. For ease of understanding, Figs. 12 and 13 illustrate the case where the refrigerant outlet holes 54c, 58c, and 62c are open directly downward.

[0074] 12 and 13 show the case where a gas-liquid two-phase refrigerant flows into the refrigerant distributors 31, 32, 41, and 42. In the case of a single-pipe structure, as shown in FIG. 12, liquid refrigerant may accumulate below the outer pipe 51, potentially reducing the amount of refrigerant circulating within the refrigerant circuit. On the other hand, in the case of a double-pipe structure, as shown in FIG. 13, the refrigerant is ejected from multiple refrigerant outlet holes 54c, 58c, and 62c provided in the inner pipes 54, 58, and 62. This disturbs the liquid refrigerant accumulating within the outer pipes 53, 57, and 61, preventing the liquid refrigerant from accumulating below the outer pipe 51. As a result, the amount of liquid refrigerant accumulating in the outer pipe 51 is reduced, allowing the refrigerant to circulate efficiently within the refrigerant circuit.

[0075] 12 and 13 show the case of separated flows in which gas refrigerant and liquid refrigerant flow separately, but the way the refrigerant flows is not limited to the examples in Fig. 12 and 13. Another example of the refrigerant flow that flows inside the refrigerant distributors 31, 32, 41, 42 is, for example, an annular flow. When the refrigerant flows as an annular flow, the liquid refrigerant forms a ring, and the annular liquid refrigerant flow covers the gas refrigerant.

[0076] The refrigerant flowing through the refrigerant outlet holes 54c, 58c, and 62c provided in the inner tubes 54, 58, and 62 may be primarily gas refrigerant or liquid refrigerant. Which refrigerant primarily flows out of the refrigerant outlet holes 54c, 58c, and 62c depends on the state of the refrigerant flowing inside the inner tubes 54, 58, and 62 and the arrangement and position of the refrigerant outlet holes 54c, 58c, and 62c. For example, when the refrigerant flows as an annular flow, the liquid refrigerant covers the refrigerant outlet holes 54c, 58c, and 62c, so that primarily the liquid refrigerant flows out of the refrigerant outlet holes 54c, 58c, and 62c. On the other hand, when the refrigerant flows as a separate flow, the flow is determined by whether the refrigerant outlet holes 54c, 58c, and 62c open upward or downward. That is, in the case of separated flow, when the refrigerant outlet holes 54c, 58c, and 62c open upward, gas refrigerant mainly flows out from the refrigerant outlet holes 54c, 58c, and 62c. In the case of separated flow, when the refrigerant outlet holes 54c, 58c, and 62c open downward, liquid refrigerant mainly flows out from the refrigerant outlet holes 54c, 58c, and 62c. Furthermore, whether the refrigerant flowing out from each refrigerant outlet hole 54c, 58c, and 62c is gas or liquid changes depending on whether the refrigerant outlet holes 54c, 58c, and 62c are located on the inlet side or the back side of the inner pipes 54, 58, and 62. Even in the case of annular flow, liquid refrigerant mainly flows out closer to the inlet side of the inner pipes 54, 58, and 62. If a large amount of liquid refrigerant flows out, the dryness of the refrigerant changes, and as the flow progresses toward the back of the inner pipes 54, 58, and 62, gas refrigerant becomes the main flow. When the liquid refrigerant decreases to the extent that the annular flow can no longer be maintained, the gas refrigerant mainly flows out from the refrigerant outlet holes 54c, 58c, and 62c.

[0077] <Refrigerant flow during heating operation> Next, the flow of refrigerant in heating operation mode will be described. Fig. 9 is a perspective view showing the connection state of the outdoor heat exchanger 3 and the outdoor heat exchanger 4 in heating operation mode in the refrigeration cycle apparatus 100 according to Embodiment 1. In Fig. 9, the refrigerant flow path connecting the outdoor heat exchanger 3 and the outdoor heat exchanger 4 is expressed by a simple connection using refrigerant piping. In Fig. 9, solid arrows indicate the direction of refrigerant flow, and hollow arrows indicate the direction of airflow generated by the outdoor fan 9.

[0078] 2 and 9, the direction of refrigerant flow during heating operation is opposite to that during cooling operation. During heating operation, the refrigerant flows into outdoor heat exchanger 3 and outdoor heat exchanger 4 via refrigerant distributor 32 and refrigerant distributor 42. Both refrigerant distributor 32 and refrigerant distributor 42 have a double-pipe structure.

[0079] In the refrigerant distributor 32, the refrigerant flows into the first internal space 53g of the outer pipe 53 through the connecting pipe 56. The refrigerant then temporarily enters the interior of the inner pipe 54 from the first internal space 53g and flows out into the second internal space 53h of the outer pipe 53 through the multiple refrigerant outlet holes 54c arranged side by side in the inner pipe 54. At this time, in the outer pipe 53, the second internal space 53h is separated from the first internal space 53g by a partition plate 55. Therefore, the refrigerant that has flowed into the second internal space 53h of the outer pipe 53 does not flow toward the first internal space 53g, but flows out into the multiple flat tubes 37 connected to the outer pipe 53 through the flat tube insertion hole 53e.

[0080] In the refrigerant distributor 42, the refrigerant flows into the first internal space 61g of the outer pipe 61 via the connecting pipe 64. The refrigerant then temporarily enters the interior of the inner pipe 62 from the first internal space 61g and flows out into the second internal space 61h of the outer pipe 61 from the multiple refrigerant outlet holes 62c arranged side by side in the inner pipe 62. At this time, in the outer pipe 61, the second internal space 61h is separated from the first internal space 61g by the partition plate 63. Therefore, the refrigerant that has flowed into the second internal space 61h of the outer pipe 61 does not flow toward the first internal space 61g, but flows out into the multiple flat tubes 47 connected to the outer pipe 61 via the flat tube insertion hole 53e.

[0081] During heating operation, the refrigerant flows out of the outdoor heat exchanger 3 and the outdoor heat exchanger 4 via the refrigerant distributor 31 and the refrigerant distributor 41. The refrigerant distributor 31 has a single-pipe structure, while the refrigerant distributor 41 has a double-pipe structure. The refrigerant that flows into the refrigerant distributor 31 from the flat tubes 37 passes through the interior of the outer tube 51 and flows out via the connecting tube 52. The refrigerant that flows into the refrigerant distributor 41 from the flat tubes 47 first flows into the second internal space 61h of the outer tube 57 and then flows into the interior of the inner tube 58 through the refrigerant outlet hole 58c. The refrigerant then passes through the interior of the inner tube 58 and flows out of the inner tube 58 into the first internal space 57g separated by the partition plate 59. The refrigerant then flows out of the refrigerant distributor 41 from the first internal space 57g via the connecting tube 60.

[0082] During heating operation, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 function as evaporators. As described above, the refrigerant distributor 41 provided on the outlet side of the outdoor heat exchanger 4 is configured with a double pipe, and is a refrigerant distributor in which a large number of refrigerant outlet holes 58c are arranged side by side in the inner pipe 58. Therefore, compared to when a refrigerant distributor with a single pipe structure is used for the refrigerant distributor 41, the refrigerant distributor 41 with a double pipe structure increases the pressure loss in the refrigerant flow path and reduces the pressure on the suction side of the compressor 1. This increases the workload required by the compressor 1, causing a problem of reduced performance as a refrigeration cycle device.

[0083] To address the above-mentioned problems, it is desirable to determine the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 of the outdoor heat exchanger 4 by considering the balance between the uniformity of refrigerant distribution in cooling operation and the pressure loss occurring in the outdoor heat exchanger 4 in heating operation. That is, some or all of the specifications of the refrigerant distributor 41 may be designed to be different from some or all of the specifications of the refrigerant distributor 42 so that the uniformity of refrigerant distribution in cooling operation can be ensured while the pressure loss in heating operation can be suppressed.

[0084] The following items can be listed as candidates for the specification items of the refrigerant distributor 41 and the refrigerant distributor 42 to be changed here. Diameter of the refrigerant outlet holes 58c and 62c (i.e., hole diameter) Arrangement interval of the refrigerant outlet holes 58c and 62c Positions of the refrigerant outlet holes 58c and 62c Number of refrigerant outlet holes 58c and 62c Diameter (inner or outer diameter) of inner tubes 58 and 62 Diameter (inner or outer diameter) of outer tubes 57 and 61

[0085] When changing the specifications of the refrigerant distributor 41 and the refrigerant distributor 42, it is desirable to appropriately determine them based on data from simulations, prototype experiments, etc. Specifically, increasing the diameter or number of the refrigerant outlet holes 58c and 62c can suppress an increase in pressure loss and change the refrigerant distribution characteristics. Changing the spacing or location of the refrigerant outlet holes 58c and 62c in accordance with the changed characteristics suppresses a decrease in distribution uniformity during cooling operation. In addition, increasing the diameters of the inner pipes 58 and 62 and the outer pipes 57 and 61 contributes to suppressing pressure loss. In this way, it is desirable to adjust the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 to achieve a favorable balance between refrigerant distribution uniformity during cooling operation and pressure loss during heating operation.

[0086] In this way, the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 are determined based on the state regarding the uniformity of refrigerant distribution when the outdoor heat exchangers 3 and 4 function as condensers and the pressure loss that occurs when the outdoor heat exchangers 3 and 4 function as evaporators.

[0087] Furthermore, some or all of the specifications of the refrigerant distributor 41 or the refrigerant distributor 42 may be designed to be different from some or all of the specifications of the refrigerant distributor 32 of the outdoor heat exchanger 3. In this case, for example, the specifications of the refrigerant distributor 41 and the refrigerant distributor 42 may be changed so that the total pressure loss of the refrigerant distributor 41 and the refrigerant distributor 42 is smaller than that of the refrigerant distributor 32 of the outdoor heat exchanger 3.

[0088] In this way, by adjusting the specifications of refrigerant distributor 41 and refrigerant distributor 42, the increase in pressure loss during heating described above can be suppressed without significantly compromising the effect of improving the uniformity of refrigerant distribution to heat exchange bodies 43A and 43B during cooling operation described above.

[0089] As described above, during heating operation, the multiple outdoor heat exchangers 3 and 4 that form the serial refrigerant flow paths both function as evaporators. Therefore, the refrigerant distributor 42 on the inlet side of the upstream outdoor heat exchanger 4 and the refrigerant distributor 32 on the inlet side of the downstream outdoor heat exchanger 3 have a double-pipe structure. The inner pipe 62 of the refrigerant distributor 42 and the inner pipe 54 of the refrigerant distributor 32 have multiple refrigerant outlet holes 62c and 54c arranged side by side, respectively. This improves the uniformity of refrigerant distribution of the gas-liquid two-phase refrigerant to the heat exchange elements 43B and 33B in the upstream outdoor heat exchanger 4 and the downstream outdoor heat exchanger 3.

[0090] <Variation 1> In the above description, the outdoor heat exchangers 3 and 4 form a series refrigerant flow path during both cooling and heating operations. However, this is not the only possible case. The circuit may be configured so that the two outdoor heat exchangers 3 and 4 can switch between a series refrigerant flow path and a parallel refrigerant flow path depending on the operating state, forming a series refrigerant flow path during cooling operation and a parallel refrigerant flow path during heating operation.

[0091] Fig. 14 is a refrigerant circuit diagram showing the configuration of a refrigeration cycle apparatus 100 according to Modification 1 of Embodiment 1. Fig. 14 shows the flow of refrigerant when the refrigeration cycle apparatus 100 according to Modification 1 is in a cooling operation state. Fig. 15 is a refrigerant circuit diagram showing the configuration of the refrigeration cycle apparatus 100 according to Modification 1 of Embodiment 1. Fig. 15 shows the flow of refrigerant when the refrigeration cycle apparatus 100 according to Modification 1 is in a heating operation state.

[0092] <Cooling operation state (in case of serial refrigerant flow path)> In Modification 1, when the refrigeration cycle apparatus 100 is in the cooling operation state, the refrigerant flow is the same as in the cooling operation state described above with reference to Fig. 1, as shown in Fig. 14. Therefore, a description thereof will be omitted here. In this way, in Modification 1, in the cooling operation state, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 form a series refrigerant flow path, as in Embodiment 1.

[0093] <Heating operation state (parallel refrigerant flow path)> In Modification 1, when the refrigeration cycle apparatus 100 is in a heating operation state, as shown in FIG. 15 , a parallel refrigerant flow path is formed in which outdoor heat exchanger 3 and outdoor heat exchanger 4 are connected in parallel. In this case, control unit 11 controls expansion valves 5 and 6 to be open, solenoid valve 7 to be closed, and solenoid valve 8 to be open. Compressor 1 draws refrigerant from accumulator 10 and compresses the refrigerant. The compressed refrigerant becomes a gas refrigerant and is discharged from compressor 1. It flows out of outdoor unit 101 via four-way valve 2 and refrigerant piping 305 and enters indoor unit 201. In indoor unit 201, the refrigerant condenses in indoor heat exchanger 21 and supplies heat to the air. After flowing out of indoor unit 201, the refrigerant flows into outdoor unit 101. In outdoor unit 101, the refrigerant branches into refrigerant piping 302 and refrigerant piping 304 and flows into expansion valve 5 and expansion valve 6, respectively. The refrigerant that has been decompressed and expanded by expansion valves 5 and 6 flows into outdoor heat exchanger 3 and outdoor heat exchanger 4, respectively, and evaporates. The refrigerant that flows out of outdoor heat exchanger 4 passes through solenoid valve 8 and merges with the refrigerant that flows out of outdoor heat exchanger 3. The merged refrigerant then flows into accumulator 10 via four-way valve 2 and refrigerant piping 306. From accumulator 10, the refrigerant is again sucked into compressor 1 and circulates through the refrigerant circuit. This forms a refrigerant circuit having refrigerant flow paths in which outdoor heat exchanger 3 and outdoor heat exchanger 4 are connected in parallel.

[0094] In the case of Modification 1, during heating operation, the two outdoor heat exchangers 3 and 4 are connected in parallel. Therefore, even if the two outdoor heat exchangers 3 and 4 have similar specifications, there is a possibility that the distribution of refrigerant to the two outdoor heat exchangers 3 and 4 will be uneven due to differences in pressure loss caused by differences in refrigerant distributors 32 and 42. In such cases, the uniformity of the distribution to the outdoor heat exchangers 3 and 4 can be improved by adjusting the apertures of the expansion valves 5 and 6 using the control unit 11. Specifically, of the expansion valves 5 and 6, the aperture of the expansion valve 5 or expansion valve 6 on the side through which more refrigerant flows is reduced, and the aperture of the expansion valve 5 or expansion valve 6 on the side through which refrigerant flows more slowly is increased.

[0095] <Variation 2> Incidentally, in the above description of the first embodiment, the case where the number of outdoor heat exchangers is two has been described. However, the configuration of the first embodiment is also applicable to cases where the number of outdoor heat exchangers is three or more. Specifically, when n outdoor heat exchangers can form a serial refrigerant flow path by controlling the refrigerant circuit, the upstream outdoor heat exchanger that functions as a condenser has a configuration similar to that of outdoor heat exchanger 3, and the downstream outdoor heat exchanger has a configuration similar to that of outdoor heat exchanger 4. It goes without saying that this provides the same effects as those of the first embodiment. Here, n is a natural number equal to or greater than 3. Furthermore, the first embodiment is for the case where n=2. Therefore, in summary of the first embodiment and its modified examples, n is a natural number equal to or greater than 2.

[0096] Fig. 16 is a refrigerant circuit diagram showing the configuration of a refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1. Fig. 17 is a diagram showing the flow of refrigerant when the refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1 is in a cooling operation state. Fig. 18 shows the flow of refrigerant when the refrigeration cycle apparatus 100 according to Modification 2 of Embodiment 1 is in a heating operation state.

[0097] The difference between the configuration in Fig. 16 and the configuration in Fig. 1 is that in Fig. 16, two outdoor heat exchangers 3A and 3B are provided instead of the outdoor heat exchanger 3 in Fig. 1. The two outdoor heat exchangers 3A and 3B are connected in parallel. Both outdoor heat exchangers 3A and 3B have the same configuration as the outdoor heat exchanger 3 in Fig. 1. Since the other configurations are the same as those in Fig. 1, their description will be omitted here.

[0098] <Refrigerant flow in outdoor heat exchanger 3 and outdoor heat exchanger 4> Next, the flow of refrigerant in the outdoor heat exchanger 3 and the outdoor heat exchanger 4 in the second modification will be described.

[0099] <Refrigerant flow during cooling operation> First, the flow of refrigerant in cooling operation will be described. In Modification 2, outdoor heat exchangers 3A and 3B are upstream outdoor heat exchangers, and outdoor heat exchanger 4 is downstream outdoor heat exchanger. As shown in Fig. 3, refrigerant distributors 31 of outdoor heat exchangers 3A and 3B have a single-pipe structure, and refrigerant distributors 32 of outdoor heat exchangers 3A and 3B have a double-pipe structure.

[0100] In Modification 2, when the refrigeration cycle apparatus 100 is in cooling operation, a series refrigerant flow path is formed in which outdoor heat exchangers 3A and 3B and outdoor heat exchanger 4 are connected in series, as shown in Fig. 17. However, outdoor heat exchanger 3A and outdoor heat exchanger 3B are connected in parallel. In this case, control unit 11 controls expansion valve 5 to be fully closed, solenoid valve 7 to be open, solenoid valve 8 to be closed, and expansion valve 6 to be fully open.

[0101] As shown in FIG. 17 , the gas refrigerant discharged from the compressor 1 flows into the refrigerant distributor 31 of the outdoor heat exchangers 3A and 3B. The gas refrigerant exchanges heat with air in the outdoor heat exchangers 3A and 3B, and a portion of the gas refrigerant condenses, resulting in a two-phase gas-liquid state. The two-phase gas-liquid refrigerant flowing out of the outdoor heat exchanger 3A and the two-phase gas-liquid refrigerant flowing out of the outdoor heat exchanger 3B merge upstream of the solenoid valve 7. The merged refrigerant then flows into the refrigerant distributor 41 of the outdoor heat exchanger 4 via the solenoid valve 7. As described with reference to FIG. 7 , the refrigerant distributor 41 has a double-pipe structure, and its inner pipe 58 is provided with a number of refrigerant outlet holes 58c. The refrigerant that flows into the refrigerant distributor 41 flows through the inner pipe 58 and into the second interior space 57h. In this way, by providing the refrigerant outlet holes 58c in the inner tube 58, the refrigerant is evenly distributed to each of the flat tubes 47 of the heat exchange element 43A. The refrigerant condensed inside the heat exchange elements 43A and 43B flows through the refrigerant distributor 42 and into the refrigerant piping 45. The refrigerant that flows out of the outdoor heat exchanger 4 flows into the indoor heat exchanger 21. In the indoor heat exchanger 21, the refrigerant exchanges heat with the air and evaporates. The refrigerant then flows out of the indoor unit 201 and into the outdoor unit 101. In the outdoor unit 101, the refrigerant flows into the accumulator 10 via the four-way valve 2 and the refrigerant piping 306. The refrigerant is sucked again from the accumulator 10 into the compressor 1 and circulates through the refrigerant circuit.

[0102] As described above, in Modification 2, among the outdoor heat exchangers 3A, 3B and the outdoor heat exchanger 4 that form a series refrigerant flow path during refrigerant operation, the refrigerant distributor 41 on the inlet side of the outdoor heat exchanger 4 located downstream has a double-pipe structure. The inner pipe 58 of the refrigerant distributor 41 has a large number of refrigerant outlet holes 58c arranged in parallel. This improves the uniformity of distribution of the refrigerant in a gas-liquid two-phase state to the heat exchange element 43A in the outdoor heat exchanger 4 located downstream.

[0103] <Heating operation state (parallel refrigerant flow path)> In Modification 2, when the refrigeration cycle apparatus 100 is in a heating operation state, as shown in FIG. 18 , a parallel refrigerant flow path is formed in which outdoor heat exchangers 3A and 3B and outdoor heat exchanger 4 are connected in parallel. In this case, the control unit 11 controls the expansion valves 5 and 6 to be open, the solenoid valve 7 to be closed, and the solenoid valve 8 to be open. The compressor 1 draws refrigerant from the accumulator 10 and compresses the refrigerant. The compressed refrigerant becomes gas refrigerant and is discharged from the compressor 1. The gas refrigerant flows through the four-way valve 2 and the refrigerant piping 305, flows out of the outdoor unit 101, and flows into the indoor unit 201. In the indoor unit 201, the refrigerant condenses in the indoor heat exchanger 21 and supplies heat to the air. After flowing out of the indoor unit 201, the refrigerant flows into the outdoor unit 101. In the outdoor unit 101, the refrigerant branches into refrigerant pipes 302 and 304 and flows into expansion valves 5 and 6, respectively. The refrigerant is reduced in pressure and expanded by expansion valves 5 and 6, flows into outdoor heat exchangers 3A and 3B, and outdoor heat exchanger 4, respectively, and evaporates. The refrigerant flowing out of outdoor heat exchanger 4 passes through solenoid valve 8 and merges with the refrigerant flowing out of outdoor heat exchangers 3A and 3B. The merged refrigerant then flows into accumulator 10 via four-way valve 2 and refrigerant pipe 306. The refrigerant is again drawn into compressor 1 from accumulator 10 and circulates through the refrigerant circuit. This forms a refrigerant circuit having a refrigerant flow path in which outdoor heat exchanger 3 and outdoor heat exchanger 4 are connected in parallel.

[0104] <Heating operation state (in case of serial refrigerant flow path)> In Modification 2, when the refrigeration cycle apparatus 100 is in a heating operation state, a series refrigerant flow path may be formed in which the outdoor heat exchangers 3A, 3B and the outdoor heat exchanger 4 are connected in series. In this case, the refrigerant flows in the opposite direction to the cooling operation state described above with reference to Fig. 17. Therefore, a description thereof will be omitted here.

[0105] As described above, the first embodiment and its modifications provide the following advantages.

[0106] When multiple outdoor heat exchangers are connected in series and function as condensers during cooling operation, the refrigerant may flow into the downstream outdoor heat exchanger in a two-phase gas-liquid state, where gas and liquid refrigerant are mixed. In the first embodiment, the refrigeration cycle apparatus 100 is configured to form a refrigerant flow path such that the outdoor heat exchanger 4 is located downstream and the outdoor heat exchanger 3 is located upstream during cooling operation. The refrigerant distributor 41 of the downstream outdoor heat exchanger 4 has a double-pipe structure, and multiple refrigerant outlet holes 58c are formed in the inner pipe 58. Therefore, when the refrigerant flows into the outdoor heat exchanger 4 in a two-phase gas-liquid state, the refrigerant distributor 41 functions to prevent uneven distribution of the refrigerant among the multiple flat tubes 47 of the outdoor heat exchanger 4. By evenly distributing the refrigerant among the multiple flat tubes 47, the required heat exchange amount is uniform across the entire surface of the heat exchange element 43 of the outdoor heat exchanger 4, preventing a decrease in heat exchange efficiency.

[0107] Specifically, the outdoor heat exchanger 4 has a refrigerant distributor 41 and a refrigerant distributor 42. Both refrigerant distributors 41 and 42 have a double-pipe structure consisting of an outer pipe and an inner pipe. Refrigerant outlet holes 58c and 62c are formed in the inner pipes 58 and 62, respectively, through which the refrigerant flows from the inner pipe to the inside of the outer pipe. Flat pipes 47 are inserted into the outer pipes 57 and 61. Therefore, even when a gas-liquid two-phase refrigerant flows into the refrigerant distributor 41 or 42, the refrigerant is distributed evenly to all of the flat pipes 47.

[0108] Even when multiple outdoor heat exchangers 3 and 4 functioning as condensers are connected to form a serial refrigerant flow path, the gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 4 located downstream can be evenly distributed.

[0109] The refrigerant distributor 31 provided in the outdoor heat exchanger 3 has a single pipe structure, so that pressure loss can be kept small during both cooling and heating operations.

[0110] Embodiment 2 19 is a perspective view showing a connection state of the outdoor heat exchanger 3C and the outdoor heat exchanger 4C in the refrigeration cycle apparatus 100 according to the second embodiment. The configuration of the refrigeration cycle apparatus 100 according to the second embodiment is basically the same as the configuration of the refrigeration cycle apparatus 100 according to the first embodiment. The difference from the first embodiment is that the second embodiment is provided with outdoor heat exchangers 3C and 4C instead of the outdoor heat exchangers 3 and 4 of the first embodiment. Since the other configurations are the same as those of the first embodiment, the description thereof will be omitted here.

[0111] 3 and 4, in the above-described first embodiment, the heat exchange elements 33 constituting the outdoor heat exchanger 3 and the heat exchange elements 43 constituting the outdoor heat exchanger 4 are each arranged in two layers in the direction along the airflow direction generated by the outdoor blower 9. In contrast, in the second embodiment, as shown in FIG. 19, the heat exchange elements 33 constituting the outdoor heat exchanger 3 and the heat exchange elements 43 constituting the outdoor heat exchanger 4 are each arranged in one layer in the direction along the airflow direction generated by the outdoor blower 9.

[0112] 19, the refrigerant flow path in which outdoor heat exchanger 3C and outdoor heat exchanger 4C are connected in series is represented by a simple connection of refrigerant piping. The outline arrows indicate the direction of the airflow generated by outdoor blower 9. The arrows next to refrigerant piping 35A, refrigerant piping 36A, and refrigerant piping 45A indicate the flow of refrigerant, with solid arrows indicating the flow of refrigerant during cooling operation and dashed arrows indicating the flow of refrigerant during heating operation.

[0113] <Configuration of outdoor heat exchanger 3C> First, the configuration of outdoor heat exchanger 3C will be described. As shown in FIG. 19, outdoor heat exchanger 3C is configured with refrigerant distributor 31, refrigerant distributor 32, and heat exchange element 33. Heat exchange element 33 is configured with a plurality of flat tubes 37 and a plurality of fins 38. The configuration of heat exchange element 33 is the same as described in embodiment 1, so description thereof will be omitted here. In embodiment 2, refrigerant distributor 31 having a single-pipe structure is provided above heat exchange element 33, and refrigerant distributor 32 having a double-pipe structure is provided below heat exchange element 33. The configurations of refrigerant distributor 31 and refrigerant distributor 32 are the same as described in embodiment 1, so description thereof will be omitted here. As shown in FIG. 19, refrigerant distributor 31 is connected to refrigerant pipe 35A via connecting pipe 52, and refrigerant distributor 32 is connected to refrigerant pipe 36A via connecting pipe 56.

[0114] <Configuration of outdoor heat exchanger 4C> Next, the configuration of the outdoor heat exchanger 4C will be described. As shown in FIG. 19, the outdoor heat exchanger 4C is composed of a refrigerant distributor 41, a refrigerant distributor 42, and a heat exchange element 43. The heat exchange element 43 is composed of a plurality of flat tubes 47 and a plurality of fins 48. The configuration of the heat exchange element 43 is the same as that described in the first embodiment, and therefore a description thereof will be omitted here. In the second embodiment, a refrigerant distributor 41 having a double-pipe structure is provided above the heat exchange element 43, and a refrigerant distributor 42 having a double-pipe structure is provided below the heat exchange element 43. The configurations of the refrigerant distributors 41 and 42 are the same as those described in the first embodiment, and therefore a description thereof will be omitted here. As shown in FIG. 19, the refrigerant distributor 41 is connected to the refrigerant pipe 36A via a connecting pipe 60, and the refrigerant distributor 42 is connected to the refrigerant pipe 45A via a connecting pipe 64.

[0115] The outdoor heat exchanger 4C may be referred to as a "heat exchanger." The heat exchange element 43 may be referred to as a "first heat exchange element." The flat tubes 47 may be referred to as "first flat tubes." The refrigerant distributor 41 may be referred to as a "first refrigerant distributor," and the refrigerant distributor 42 may be referred to as a "second refrigerant distributor." The outer tube 57 may be referred to as a "first outer tube," the inner tube 58 as a "first inner tube," and the partition plate 59 as a "first partition plate." The outer tube 61 may be referred to as a "second outer tube," the inner tube 62 as a "second inner tube," and the partition plate 63 as a "second partition plate." The tube end 47c of the flat tube 47 inserted in the refrigerant distributor 41 may be referred to as "one end of the first flat tube," and the tube end 47d of the flat tube 47 inserted in the refrigerant distributor 42 may be referred to as "the other end of the first flat tube."

[0116] Furthermore, the outdoor heat exchanger 3C may be referred to as the "second heat exchanger." The heat exchange element 33 may be referred to as the "second heat exchange element." The flat tubes 37 may be referred to as the "second flat tubes." The refrigerant distributor 31 may be referred to as the "third refrigerant distributor," and the refrigerant distributor 32 may be referred to as the "fourth refrigerant distributor." The outer tube 51 may be referred to as the "third outer tube." The outer tube 53 may be referred to as the "fourth outer tube," the inner tube 54 may be referred to as the "fourth inner tube," and the partition plate 55 may be referred to as the "fourth partition plate." The tube end 37c of the flat tube 37 inserted into the refrigerant distributor 31 may be referred to as the "one end of the second flat tube," and the tube end 37d of the flat tube 37 inserted into the refrigerant distributor 32 may be referred to as the "other end of the second flat tube."

[0117] <Refrigerant flow during cooling operation> First, the flow of refrigerant during cooling operation will be described. As shown in FIG. 19, gas refrigerant discharged from compressor 1 (see FIG. 1) flows from refrigerant pipe 35A through connecting pipe 52 into refrigerant distributor 31. The inflowing refrigerant is partially condensed in outdoor heat exchanger 3, becoming a two-phase gas-liquid state, and flows out through refrigerant distributor 32 into refrigerant pipe 36A. The refrigerant then flows in this two-phase gas-liquid state into outdoor heat exchanger 4. In outdoor heat exchanger 4, the refrigerant first flows into refrigerant distributor 41 through connecting pipe 60. Refrigerant distributor 41 has a double-pipe structure, and its inner pipe 58 is provided with a number of refrigerant outlet holes 58c. As the refrigerant flows into refrigerant distributor 41, it flows through inner pipe 58 and flows out from refrigerant outlet holes 58c into second interior space 57h of outer pipe 57. In this way, by providing the refrigerant outlet holes 58c in the inner tube 58, the refrigerant is evenly distributed to each flat tube 47 of the heat exchange element 43A. The refrigerant condensed inside the heat exchange element 43 flows out from the refrigerant distributor 42 through the connecting pipe 64 to the refrigerant pipe 45A.

[0118] As described above, among the outdoor heat exchangers 3C and 4C that form a series refrigerant flow path during refrigerant operation, the refrigerant distributor 41 on the inlet side of the outdoor heat exchanger 4C located downstream has a double-pipe structure. The inner pipe 58 of the refrigerant distributor 41 has a large number of refrigerant outlet holes 58c arranged in parallel. This improves the uniformity of distribution of the gas-liquid two-phase refrigerant to the heat exchange element 43 in the outdoor heat exchanger 4C located downstream.

[0119] <Refrigerant flow during heating operation> Next, the flow of refrigerant in heating operation mode will be described. As can be seen by comparing the solid arrows and dashed arrows in Figure 19, the direction of refrigerant flow in heating operation mode is opposite to that in cooling operation mode. In heating operation mode, the refrigerant flows into outdoor heat exchanger 3C and outdoor heat exchanger 4C via refrigerant distributor 32 and 42. Both refrigerant distributor 32 and 42 have a double-pipe structure.

[0120] As described above, the outdoor heat exchangers 3C and 4C, which form a series refrigerant flow path, function together as evaporators during heating operation. Therefore, the refrigerant distributor 42 on the inlet side of the upstream outdoor heat exchanger 4C and the refrigerant distributor 32 on the inlet side of the downstream outdoor heat exchanger 3C have a double-pipe structure. The inner pipe 62 of the refrigerant distributor 42 and the inner pipe 54 of the refrigerant distributor 32 have multiple refrigerant outlet holes 62c and multiple refrigerant outlet holes 54c, respectively, arranged side by side. This improves the uniformity of the distribution of the gas-liquid two-phase refrigerant to the heat exchange elements 43 and 33 in the upstream outdoor heat exchanger 4C and the downstream outdoor heat exchanger 3C.

[0121] As described above, in the second embodiment as well, the refrigerant distributor 41 of the outdoor heat exchanger 4C, which is located downstream during cooling operation, is configured with a double-pipe structure, and therefore the same effects as in the first embodiment can be obtained.

[0122] Embodiment 3 Fig. 20 is a perspective view showing the appearance of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to embodiment 3. Fig. 21 is a plan view schematically showing an example of the configuration of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to embodiment 3.

[0123] As shown in FIGS. 20 and 21, the outdoor unit 101 includes outdoor heat exchangers 3 and 4, refrigerant pipes 35, 36, and 45 (see FIG. 2) that connect the outdoor heat exchangers 3 and 4, a housing 101a, and an outdoor blower 9.

[0124] As shown in FIG. 20 , the housing 101a has a box-like shape. As shown in FIG. 21 , the housing 101a accommodates outdoor heat exchangers 3 and 4. Although not shown in FIG. 21 , the housing 101a also accommodates compressor 1, four-way valve 2, expansion valves 5 and 6, solenoid valves 7 and 8, a control box (not shown) accommodating a control board constituting control unit 11, and other components shown in FIG. 1 . An outdoor blower 9 is disposed in an upper portion 101b of the housing 101a. The outdoor blower 9 rotates to generate an airflow as indicated by the white arrows in FIG. 20 . The air is drawn into the housing 101a from at least two of the four sides of the housing 101a. After passing through the outdoor heat exchangers 3 and 4, the air is blown upward from air outlets provided in the upper portion 101b of the housing 101a.

[0125] In the example of Fig. 21(a), the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each have a rectangular shape in a plan view. In the example of Fig. 21(a), the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged opposite each other. Also, in the example of Fig. 21(a), the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged along part of the side surface of the housing 101a. In other words, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged along two of the four side surfaces of the housing 101a.

[0126] In the example of Fig. 21(b), the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each have an L-shape in a plan view. In the example of Fig. 21(b), the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged in point-symmetric positions. Also, in the example of Fig. 21(b), the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged along all of the side surfaces of the housing 101a. In other words, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged along the four side surfaces of the housing 101a.

[0127] The example of FIG. 21(c) shows a case where there are three outdoor heat exchangers, as in Modification 2 of Embodiment 1 shown in FIGS. 16 to 18. In the example of FIG. 21(c), the outdoor heat exchangers 3A, 3B, and 4 are arranged in a U-shape in plan view. In the example of FIG. 21(c), the outdoor heat exchangers 3A, 3B, and 4 are arranged along parts of the side surfaces of the housing 101a. In other words, the outdoor heat exchangers 3A, 3B, and 4 are arranged along three side surfaces of the housing 101a.

[0128] <Modification> Fig. 22 is a perspective view showing the appearance of an outdoor unit 101 provided in a refrigeration cycle apparatus 100 according to a modified example of embodiment 3. Fig. 23 is a plan view schematically showing an example of the configuration of the outdoor unit 101 provided in the refrigeration cycle apparatus 100 according to embodiment 3.

[0129] In the example of Fig. 21, one outdoor fan 9 is arranged in the upper part 101b of the housing 101a. However, this is not limited to this. The number of outdoor fans 9 may be one as shown in Fig. 21, or may be two as shown in Fig. 1 shown in the first embodiment. Fig. 22 shows a case where two outdoor fans 9 are provided in the upper part 101b of the housing 101a.

[0130] In the example of Fig. 23, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 each have an L-shape in a plan view. In the example of Fig. 23, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged in line-symmetric positions. Also, in the example of Fig. 23, the outdoor heat exchanger 3 and the outdoor heat exchanger 4 are arranged along three of the four side surfaces of the housing 101a. [Explanation of symbols]

[0131] 1 compressor, 2 four-way valve, 2a connection port, 2b connection port, 2c connection port, 2d connection port, 3 outdoor heat exchanger, 3A outdoor heat exchanger, 3B outdoor heat exchanger, 3C outdoor heat exchanger, 3a connection port, 3b connection port, 4 outdoor heat exchanger, 4C outdoor heat exchanger, 4a connection port, 4b connection port, 5 expansion valve, 6 expansion valve, 7 solenoid valve, 8 solenoid valve, 9 outdoor blower, 10 accumulator, 11 control unit, 21 indoor heat exchanger, 21a connection port, 21b connection port, 22 indoor blower, 23 expansion valve, 31 refrigerant distributor, 32 refrigerant distributor, 33 heat exchange element, 33A heat exchange element, 33B heat exchange element, 34 return header, 35 refrigerant piping, 35A refrigerant piping, 36 refrigerant piping, 36A Refrigerant piping, 37 flat tube, 37a pipe end, 37b pipe end, 37c pipe end, 37d pipe end, 38 fin, 41 refrigerant distributor, 42 refrigerant distributor, 43 heat exchange element, 43A heat exchange element, 43B heat exchange element, 44 folded header, 45 refrigerant piping, 45A refrigerant piping, 47 flat tube, 47a pipe end, 47b pipe end, 47c pipe end, 47d pipe end, 48 fin, 51 outer tube, 51a pipe end, 51b pipe end, 51c closure plate, 51d closure plate, 51e flat tube insertion hole, 52 connecting pipe, 52a lower end, 53 outer tube, 53a pipe end, 53b pipe end, 53c closure plate, 53d closure plate, 53e Flat tube insertion hole, 53f inner wall, 53g first inner space, 53h second inner space, 54 inner pipe, 54a pipe end, 54b pipe end, 54c refrigerant outflow hole, 54f outer wall, 55 partition plate, 55a through hole, 56 connecting pipe, 56a lower end, 57 outer pipe, 57a pipe end, 57b pipe end, 57c closing plate, 57d closing plate, 57e flat tube insertion hole, 57f inner wall, 57g first inner space, 57h second inner space, 58 inner pipe, 58a pipe end, 58b pipe end, 58c refrigerant outflow hole, 58f outer wall, 59 partition plate, 59a through hole, 60 connecting pipe, 60a lower end, 61 outer pipe, 61a pipe end, 61b pipe end, 61c Closing plate, 61d closing plate, 61e flat tube insertion hole, 61f inner wall, 61g first inner space, 61h second inner space, 62 inner pipe, 62a pipe end, 62b pipe end, 62c refrigerant outflow hole, 62f outer wall, 63 partition plate, 63a through hole, 64 connecting pipe, 100 refrigeration cycle device, 101Outdoor unit, 101a housing, 101b upper part, 201 indoor unit, 300 refrigerant piping, 301 refrigerant piping, 302 refrigerant piping, 303 refrigerant piping, 304 refrigerant piping, 305 refrigerant piping, 306 refrigerant piping, 307 refrigerant piping, 308 refrigerant piping, 310 refrigerant piping, P1 connection port, P2 connection port.

Claims

1. a first heat exchange element including a plurality of first flat tubes arranged at intervals in a first direction and having a tube axis direction extending in a second direction intersecting the first direction; a first refrigerant distributor into which one ends of the plurality of first flat tubes are inserted; a second refrigerant distributor into which the other ends of the plurality of first flat tubes are inserted; Equipped with The first refrigerant distributor is a first outer tube extending in the first direction and into which the one ends of the plurality of first flat tubes are inserted; a first inner tube extending in the first direction, disposed inside the first outer tube, and having a plurality of first refrigerant outlet holes spaced apart from one another in the first direction; a first partition plate joined to an inner wall of the first outer pipe with the first inner pipe penetrating the plate thickness; and The second refrigerant distributor is a second outer tube extending in the first direction and into which the other ends of the first flat tubes are inserted; a second inner tube extending in the first direction, disposed inside the second outer tube, and having a plurality of second refrigerant outlet holes spaced apart from one another in the first direction; a second partition plate joined to an inner wall of the second outer pipe with the second inner pipe penetrating the plate thickness; a first heat exchanger having a second heat exchange element including a plurality of second flat tubes arranged at intervals in a third direction and having a tube axis direction extending in the second direction intersecting the third direction; a third refrigerant distributor into which one ends of the plurality of second flat tubes are inserted; a fourth refrigerant distributor into which the other ends of the second flat tubes are inserted; Equipped with The third refrigerant distributor is a third outer tube extending in the third direction and into which the one ends of the second flat tubes are inserted; and The fourth refrigerant distributor is a fourth outer tube extending in the third direction and into which the other ends of the second flat tubes are inserted; a fourth inner tube extending in the third direction, disposed inside the fourth outer tube, and having a plurality of fourth refrigerant outlet holes spaced apart from one another in the third direction; a fourth partition plate joined to an inner wall of the fourth outer pipe with the fourth inner pipe penetrating the plate thickness; a second heat exchanger having Equipped with When the first heat exchanger functions as a condenser, the first heat exchanger is connected in series with the second heat exchanger functioning as a condenser; the second heat exchanger is disposed upstream of the first heat exchanger in a refrigerant flow direction, The first flat tube is a leeward-side first flat tube disposed on the leeward side in the air flow direction and having the one end of the first flat tube; a windward-side first flat tube disposed on the windward side in the air flow direction and having the other end of the first flat tube; Including, The second flat tube is a leeward-side second flat tube disposed on the leeward side in the air flow direction and having the one end of the second flat tube; a windward-side second flat tube disposed on the windward side in the air flow direction and having the other end of the second flat tube; Including, The first refrigerant distributor and the second refrigerant distributor are the diameters or the numbers of the first refrigerant outlet holes and the second refrigerant outlet holes; an arrangement interval or an arrangement position of the plurality of first refrigerant outlet holes and the plurality of second refrigerant outlet holes; diameters of the first inner tube and the second inner tube; the diameters of the first outer tube and the second outer tube; At least one of the specifications is different, heat exchanger.

2. When the first heat exchanger functions as a condenser, The refrigerant flows from the first refrigerant distributor into the one end of the first flat tube, flows through the inside of the first flat tube, and flows out from the other end of the first flat tube to the second refrigerant distributor. The heat exchanger of claim 1 .

3. The refrigerant flowing from the first refrigerant distributor into the one end of the first flat tube is in a gas-liquid two-phase state.

3. The heat exchanger of claim 2.

4. The end opposite to the one end of the downwind side first flat tube and the end opposite to the other end of the upwind side first flat tube are connected via a first folded header. The heat exchanger according to any one of claims 1 to 3.

5. When the second heat exchanger functions as a condenser, The refrigerant flows from the third refrigerant distributor into the one end of the second flat tube, flows through the inside of the second flat tube, and flows out from the other end of the second flat tube to the fourth refrigerant distributor. The heat exchanger according to any one of claims 1 to 3.

6. The refrigerant flowing from the third refrigerant distributor into the one end of the second flat tube is in a gas state.

6. The heat exchanger according to claim 5.

7. The end opposite to the one end of the downwind side second flat tube and the end opposite to the other end of the upwind side second flat tube are connected via a second folded header. The heat exchanger according to any one of claims 1 to 3.

8. A refrigeration cycle device equipped with an outdoor unit, The outdoor unit is A first heat exchanger and a second heat exchanger according to any one of claims 1 to 3; a refrigerant pipe connecting the first heat exchanger and the second heat exchanger; a box-shaped housing that houses the first heat exchanger and the second heat exchanger; a blower that is disposed in an upper portion of the housing, that is rotationally driven to form an air flow, and that blows the air that has passed through the first heat exchanger and the second heat exchanger upward from an upper surface of the housing; Equipped with the first heat exchanger and the second heat exchanger are arranged along some or all of four side surfaces of the housing; Refrigeration cycle equipment.

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