Heat exchanger, production method for heat exchanger, and refrigeration cycle device

Abstract

A heat exchanger according to the present invention comprises: a first heat exchanger that includes a plurality of first heat transfer tubes that are provided at intervals, a first upper header that is provided at an upper end of the plurality of first heat transfer tubes, and a first lower header that is provided at a lower end of the plurality of first heat transfer tubes; a second heat exchanger that includes a plurality of second heat transfer tubes that are provided at intervals, a second upper header that is provided at an upper end of the plurality of second heat transfer tubes, and a second lower header that is provided at a lower end of the plurality of second heat transfer tubes; and connection piping that connects the first lower header of the first heat exchanger and the second upper header of the second heat exchanger. A first connection port to which the connection piping is connected is formed in the first lower header on a side in the extension direction of the plurality of first heat transfer tubes, and a second connection port to which the connection piping is connected is formed in the second upper header on a side in the extension direction of the plurality of second heat transfer tubes.

Description

Heat exchanger, method for manufacturing a heat exchanger, and refrigeration cycle apparatus

[0001] The present disclosure relates to a heat exchanger, a method for manufacturing a heat exchanger, and a refrigeration cycle apparatus.

[0002] For example, Patent Document 1 discloses a refrigeration cycle apparatus having a plurality of heat exchangers in which heat transfer tubes are arranged by being extended in the vertical direction. Patent Document 1 has a configuration in which a plurality of heat exchangers are connected by connection pipes such that the refrigerant always becomes a downward flow during the condensation flow. During the condensation flow, when the refrigerant flows into the upper header of one heat exchanger, it descends through the heat transfer tube and flows into the lower header, rises through the connection pipe, flows into the upper header of another heat exchanger and descends through the heat transfer tube, and then flows out through the lower header.

[0003] Japanese Patent Application Laid-Open No. 2001-174022

[0004] In Patent Document 1, since the connection pipes connecting a plurality of heat exchangers project horizontally from the sides of the upper and lower headers, when connecting a plurality of heat exchangers with the connection pipes, it is necessary to bend the connection pipes multiple times. Further, since the pipes project horizontally from the headers, it is difficult to arrange a plurality of heat exchangers in close proximity, air flows between the plurality of heat exchangers, bypasses the heat exchangers, and reduces the heat exchange performance. In order to prevent the air flow so that the air does not bypass the heat exchanger, a blocking portion must be provided. In some cases, the area of the blocking portion increases, and the structure and manufacturability become complicated. Therefore, it is not possible to improve the structure and manufacturability when arranging the heat exchangers while maintaining the heat exchange performance.

[0005] An object of the present disclosure is to provide a heat exchanger, a method for manufacturing a heat exchanger, and a refrigeration cycle apparatus capable of achieving both structural simplification and manufacturability and heat exchange performance when having a plurality of heat exchangers having a plurality of heat transfer tubes.

[0006] The heat exchanger according to this disclosure comprises: a first heat exchanger including a plurality of first heat transfer tubes arranged at intervals, a first upper header provided at one upper end of the plurality of first heat transfer tubes, and a first lower header provided at one lower end of the plurality of first heat transfer tubes; a second heat exchanger including a plurality of second heat transfer tubes arranged at intervals, a second upper header provided at one upper end of the plurality of second heat transfer tubes, and a second lower header provided at one lower end of the plurality of second heat transfer tubes; and connecting piping connecting the first lower header of the first heat exchanger and the second upper header of the second heat exchanger, wherein a first connection port formed in the first lower header and to which the connecting piping is connected is provided on the extending side of the plurality of first heat transfer tubes, and a second connection port formed in the second upper header and to which the connecting piping is connected is provided on the extending side of the plurality of second heat transfer tubes.

[0007] A method for manufacturing a heat exchanger according to this disclosure comprises the steps of joining the plurality of first heat transfer tubes, the first lower header, the connecting pipe, the second upper header, and the plurality of second heat transfer tubes while the first heat exchanger and the second heat exchanger are arranged in parallel, and twisting the connecting pipe so that the first heat exchanger and the second heat exchanger are not parallel.

[0008] The refrigeration cycle device according to this disclosure comprises the heat exchanger described above and a refrigerant circuit to which the heat exchanger is connected and through which a refrigerant circulates, wherein when the heat exchanger acts as a condenser, the refrigerant flowing through the heat exchanger descends through the plurality of first heat transfer tubes, rises through the connecting pipes, and descends through the plurality of second heat transfer tubes.

[0009] According to this disclosure, the first heat exchanger and the second heat exchanger can be placed closer together, which increases the front surface area that contributes to heat exchange while miniaturizing or reducing the components that suppress air leakage, thereby achieving both improved performance and a rationalized structure for the heat exchanger.

[0010] This is a circuit diagram of a refrigeration cycle device according to Embodiment 1 of the present disclosure. This is a perspective view of the first heat exchanger according to Embodiment 1 of the present disclosure. This is a cross-sectional view showing the first heat transfer tube of the first heat exchanger according to Embodiment 1 of the present disclosure. This is a schematic top view of the first lower header of the heat exchanger according to Embodiment 1 of the present disclosure. This is a schematic bottom view of the second upper header of the heat exchanger according to Embodiment 1 of the present disclosure. This is an internal configuration diagram showing the heat exchanger according to Embodiment 1 of the present disclosure housed in an outdoor unit. This is a top view of the heat exchanger according to Embodiment 1 of the present disclosure. This is a front view of the heat exchanger according to Embodiment 1 of the present disclosure. This is a side view of the heat exchanger according to Embodiment 1 of the present disclosure. This is a perspective view showing the first heat exchanger according to Modification 1 of Embodiment 1 of the present disclosure. This is a cross-sectional view showing the first heat transfer tube of the first heat exchanger according to Modification 2 of Embodiment 1 of the present disclosure. This is a cross-sectional view showing the first heat transfer tube of the first heat exchanger according to Modification 3 of Embodiment 1 of the present disclosure. This is a top view of a heat exchanger according to a comparative example. This is a front view of a heat exchanger according to a comparative example. This is a side view of a heat exchanger according to a comparative example. This is a top view of a heat exchanger according to Embodiment 2 of the present disclosure. This is a front view of a heat exchanger according to Embodiment 2 of the present disclosure. This is a side view of a heat exchanger according to Embodiment 2 of the present disclosure. This is a top view of a heat exchanger according to Embodiment 3 of the present disclosure. This is a front view of a heat exchanger according to Embodiment 3 of the present disclosure. This is a side view of a heat exchanger according to Embodiment 3 of the present disclosure. This is a top view of a heat exchanger according to Embodiment 4 of the present disclosure. This is a front view of a heat exchanger according to Embodiment 4 of the present disclosure. This is a side view of a heat exchanger according to Embodiment 4 of the present disclosure. This is a top view illustrating the manufacturing method of a heat exchanger according to Embodiment 5 of the present disclosure. This is a side view illustrating the manufacturing method of a heat exchanger according to Embodiment 5 of the present disclosure. This is a top view illustrating the manufacturing method of a heat exchanger according to Embodiment 5 of the present disclosure.

[0011] Embodiments of this disclosure will be described below with reference to the drawings. This disclosure is not limited to the embodiments described below and can be modified in various ways without departing from the spirit of this disclosure. Furthermore, this disclosure includes all possible combinations of the configurations shown in each of the embodiments described below. In particular, the combinations of components are not limited to the combinations in each embodiment, and components described in one embodiment can be applied to another embodiment. Furthermore, the configurations shown in the drawings are examples of the configurations of this disclosure and do not limit this disclosure by the configurations shown in the drawings. In addition, in the following description, terms indicating direction (e.g., "up," "down," "right," "left," "front," "back," etc.) will be used as appropriate to facilitate understanding, but these are for illustrative purposes only and do not limit this disclosure. Furthermore, in each drawing, components with the same reference numerals are the same or equivalent components, and this is common throughout the entire specification. Note that the relative dimensions or shapes of each component in each drawing may differ from those of the actual components.

[0012] Embodiment 1. Figure 1 is a circuit diagram of a refrigeration cycle device 1 according to Embodiment 1 of the present disclosure. The refrigeration cycle device 1 is, for example, an air conditioning device that adjusts the air in a space to be air-conditioned, and as shown in Figure 1, comprises an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 is provided with, for example, a compressor 6, a heat exchanger 8, a blower 9, an expansion unit 10, and a control device 13. The indoor unit 3 is provided with, for example, a third heat exchanger 11 and a load-side blower 12.

[0013] The compressor 6, heat exchanger 8, expansion unit 10, and third heat exchanger 11 are connected by refrigerant piping 5 to form a refrigerant circuit 4. The compressor 6 draws in refrigerant in a low-temperature and low-pressure state, compresses the drawn-in refrigerant to a high-temperature and high-pressure state, and discharges it. The compressor 6 is, for example, a capacity-controllable inverter compressor. The heat exchanger 8 exchanges heat between, for example, the outdoor air and the refrigerant. The heat exchanger 8 acts as a condenser and performs heating operation. The expansion unit 10 is a pressure reducing valve or expansion valve that reduces the pressure of the refrigerant and expands it. The expansion unit 10 is, for example, an electronic expansion valve whose opening degree can be adjusted.

[0014] The heat exchanger 8 includes, for example, a first heat exchanger 8a and a second heat exchanger 8b, with the first heat exchanger 8a and the second heat exchanger 8b connected in series. The heat exchanger 8 may have three or more heat exchangers 8. The first heat exchanger 8a and the second heat exchanger 8b are connected by connecting pipes 7. The blower 9 is a device that supplies outdoor air to the heat exchanger 8. Specifically, the blower 9 supplies outdoor air to both the first heat exchanger 8a and the second heat exchanger 8b.

[0015] The third heat exchanger 11 exchanges heat between, for example, indoor air and a refrigerant. The third heat exchanger 11 acts as an evaporator and performs cooling operation. The load-side fan 12 is a device that supplies indoor air to the third heat exchanger 11.

[0016] The control device 13 consists of a CPU (also called a Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or processor) that executes a program stored in dedicated hardware or storage device. When the control device 13 is dedicated hardware, it may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Each of the functional units realized by the control device 13 may be realized by individual hardware, or each functional unit may be realized by a single piece of hardware.

[0017] When the control device 13 is a CPU, each function performed by the control device 13 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in a storage device. The CPU realizes each function by reading and executing the programs stored in the storage device. The control device 13 may be configured to realize some of its functions with dedicated hardware and some with software or firmware. The storage device may be configured as a hard disk, or as a volatile storage device such as random access memory (RAM) that can temporarily store data. Alternatively, the storage device may be configured as a non-volatile storage device such as flash memory that can store data for a long period of time. Although Embodiment 1 illustrates the case where the control device 13 is installed in the outdoor unit 2, the control device 13 may be installed in the indoor unit 3, or the control device 13 may be installed in an external unit.

[0018] The outdoor unit 2 may be provided with a refrigerant leak detection unit (not shown). The refrigerant leak detection unit detects when refrigerant has leaked and is, for example, a refrigerant detection sensor. The refrigerant leak detection unit may be based on the operating state of the refrigeration cycle device 1. The operating state includes, for example, a low pressure, a high discharge temperature of the compressor 6, a high suction superheating degree of the compressor 6, or a low subcooling degree.

[0019] (Cooling Operation) Next, the operation of the refrigeration cycle device 1 will be explained. In cooling operation, the refrigerant drawn into the compressor 6 is compressed by the compressor 6 and discharged in a high-temperature and high-pressure gaseous state. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 6 flows into the heat exchanger 8, which acts as a condenser, and in the heat exchanger 8, it exchanges heat with the outside air supplied by the blower 9, condenses, and liquefies.

[0020] Specifically, the refrigerant first flows into the second heat exchanger 8b, where it exchanges heat with the outdoor air supplied by the blower 9. The refrigerant that has undergone heat exchange in the second heat exchanger 8b then flows into the first heat exchanger 8a, where it exchanges heat with the outdoor air supplied by the blower 9, condenses, and liquefies. The condensed liquid refrigerant flows into the expansion section 10, where it expands and depressurizes to become a low-temperature, low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant then flows into the third heat exchanger 11, which acts as an evaporator, where it exchanges heat with the indoor air supplied by the load-side blower 12, evaporates, and turns into a gas. At this time, the indoor air is cooled, and cooling is performed in the room. The evaporated low-temperature, low-pressure gaseous refrigerant is drawn into the compressor 6.

[0021] In Embodiment 1, the example is given for the case where the refrigeration cycle device 1 is a cooling-only unit, but the refrigeration cycle device 1 may also be a heating-only unit. Furthermore, the refrigeration cycle device 1 may have a flow path switching device. In this case, the refrigeration cycle device 1 can switch between cooling operation and heating operation. When the refrigeration cycle device 1 is operating in heating operation, the third heat exchanger 11 functions as a condenser, and the first heat exchanger 8a and the second heat exchanger 8b function as condensers.

[0022] Figure 2 is a perspective view of a first heat exchanger 8a according to Embodiment 1 of the present disclosure. As shown in Figure 2, the first heat exchanger 8a comprises a plurality of first heat transfer tubes 81a, a first upper header 82a, and a first lower header 83a. The first heat exchanger 8a exchanges heat with air passing in the direction of the white arrow W. The first upper header 82a is provided with an upper inlet / outlet pipe 802a, and the first lower header 83a is provided with a first connecting pipe 803a.

[0023] The first upper header 82a is connected to one upper end of the plurality of first heat transfer tubes 81a, and the first lower header 83a is connected to one lower end of the plurality of first heat transfer tubes 81a. The upper inlet / outlet pipe 802a is connected to the refrigerant piping 5 and is a pipe through which the refrigerant flows. The upper inlet / outlet pipe 802a is provided, for example, in the first upper header 82a in the direction in which the plurality of first heat transfer tubes 81a extend.

[0024] The multiple first heat transfer tubes 81a are arranged perpendicular to each other in their axial direction. That is, the multiple first heat transfer tubes 81a are arranged to extend along the z direction, which is parallel to the direction of gravity g. The z direction is the direction of extension of the multiple first heat transfer tubes 81a. This arrangement is called a vertical tube arrangement. The multiple first heat transfer tubes 81a constitute the first heat exchanger.

[0025] Multiple first heat transfer tubes 81a are arranged with spacing between them in the y-direction, which is perpendicular to the z-direction. Each of the multiple first heat transfer tubes 81a is arranged in the y-direction at a predetermined pitch and at a predetermined interval. The spacing between each of the multiple first heat transfer tubes 81a forms an air passage for the airflow from outside, which is the heat exchange fluid supplied by the blower 9. The spacing between each of the multiple first heat transfer tubes 81a is equal to the distance between two adjacent first heat transfer tubes 81a.

[0026] The first connecting pipe 803a is located on the side of the first lower header 83a in the direction in which the plurality of first heat transfer tubes 81a extend. The first connecting pipe 803a is connected to the connecting pipe 7 and is a pipe through which the refrigerant flows.

[0027] Among the multiple first heat transfer tubes 81a, multiple first fins 84a are arranged between two adjacent first heat transfer tubes 81a. The multiple first fins 84a are, for example, corrugated fins. The multiple first fins 84a are arranged along the z-direction, which is the direction in which the multiple first heat transfer tubes 81a extend. The first heat exchanger 8a is, for example, a fin-and-tube type in which the multiple first heat transfer tubes 81a extend in the z-direction, which is the vertical direction. In this case, by providing corrugated fins as the multiple first fins 84a, condensation water can be drained efficiently.

[0028] Figure 3 is a cross-sectional view showing the first heat transfer tube 81a of the first heat exchanger 8a according to Embodiment 1 of the present disclosure. As shown in Figure 3, each of the plurality of first heat transfer tubes 81a has a cross-sectional shape in a plane perpendicular to the z-direction, for example, a flattened shape.

[0029] The multiple first heat transfer tubes 81a have a rectangular or approximately rectangular cross-sectional shape in a plane perpendicular to the z-direction, with a long side and a short side. The x-direction, where the long side extends, is called the longitudinal direction of the cross-section of the multiple first heat transfer tubes 81a, and the y-direction, where the short side extends, is called the short direction of the cross-section of the multiple first heat transfer tubes 81a. Because the multiple first heat transfer tubes 81a are flattened, their projected area when viewed from the airflow direction is reduced compared to when circular tubes are used, thus reducing airflow resistance.

[0030] The multiple first heat transfer tubes 81a are composed of porous, flattened tubes having multiple internal flow channels 811a in a cross-section in a plane perpendicular to the z-direction. In the multiple first heat transfer tubes 81a, the multiple internal flow channels 811a are arranged in a line along the x-direction, from one end to the other in the longitudinal direction of the cross-section of the multiple first heat transfer tubes 81a.

[0031] The refrigerant flowing through the multiple first heat transfer tubes 81a is distributed or merged at the first upper header 82a and the first lower header 83a.

[0032] Figure 4 is a schematic top view of the first lower header 83a of the heat exchanger 8 according to Embodiment 1 of the present disclosure. Figure 5 is a schematic bottom view of the second upper header 82b of the heat exchanger 8 according to Embodiment 1 of the present disclosure.

[0033] As shown in Figure 4, the first lower header 83a has multiple heat transfer tube insertion holes 801 into which each of the multiple first heat transfer tubes 81a (see Figure 2) is inserted, and a first connection port 813a into which the first connecting pipe 803a (see Figure 2) is connected. Also, as shown in Figure 5, the second upper header 82b has multiple heat transfer tube insertion holes 801 into which each of the multiple second heat transfer tubes 81b (see Figure 6) is inserted, and a second connection port 813b into which the second connecting pipe 803b (see Figure 6) is connected. The first connection port 813a is provided on the side of the first lower header 83a in the direction of extension of the multiple first heat transfer tubes 81a, that is, on the upper surface side of the first lower header 83a, and opens facing the direction of extension of the multiple first heat transfer tubes 81a. The second connecting pipe 803b is provided on the side of the second upper header 82b that is in the direction of extension of the plurality of second heat transfer tubes 81b, that is, on the lower surface side of the first lower header 83a, and opens facing the direction of extension of the plurality of second heat transfer tubes 81b. The first connection port 813a is located near one end in the longitudinal direction of the first lower header 83a, and the second connection port 813b is located near the other end in the longitudinal direction of the second upper header 82b.

[0034] When the first heat exchanger 8a functions as a condenser, the first connecting pipe 803a allows the refrigerant that has passed through the first lower header 83a to flow into the connecting pipe 7, and the second connecting pipe 803b allows the refrigerant that has passed through the connecting pipe 7 to flow into the second upper header 82b. Therefore, the refrigerant that has descended through the multiple first heat transfer tubes 81a merges at the first lower header 83a through the multiple heat transfer tube insertion holes 801, and flows into the connecting pipe 7 via the first connecting pipe 803a extending from the first connection port 813a. The refrigerant that has flowed into the connecting pipe 7 rises up the connecting pipe 7 to the second connecting pipe 803b, and from the second connecting pipe 803b, it flows into the second lower header 83b via the second connection port 813b.

[0035] The first upper header 82a (see Figure 2) has holes (not shown) into which one upper end of each of the multiple first heat transfer tubes 81a is inserted, similar to the first lower header 83a. The first upper header 82a also has a connection port (not shown) into which the upper inlet / outlet pipe 802a (see Figure 2) is connected. The second lower header 83b (see Figure 8) has holes (not shown) into which each of the multiple second heat transfer tubes 81b is inserted, similar to the second upper header 82b. The second lower header 83b also has a connection port (not shown) into which the lower inlet / outlet pipe 802b (see Figure 6) is connected.

[0036] The configuration of the first connection port 813a, the second connection port 813b, the connection port to which the upper inlet / outlet pipe 802a is connected, and the connection port to which the lower inlet / outlet pipe 802b is connected is not particularly limited, as long as each can be connected to the piping to which it is connected.

[0037] The multiple first heat transfer tubes 81a are made of a thermally conductive metallic material. Examples of materials used to make up the multiple first heat transfer tubes 81a include aluminum, aluminum alloy, copper, or copper alloy. The multiple first heat transfer tubes 81a are manufactured by extrusion, in which heated material is extruded through a die to form the illustrated cross-section. Alternatively, the multiple first heat transfer tubes 81a may be manufactured by drawing, in which material is drawn out through a die to form the illustrated cross-section. The manufacturing method for the multiple first heat transfer tubes 81a can be appropriately selected according to the cross-sectional shape of the multiple first heat transfer tubes 81a.

[0038] Figure 6 is an internal configuration diagram showing the heat exchanger 8 according to Embodiment 1 of the present disclosure housed in the outdoor unit 2. As shown in Figure 6, the outdoor unit 2 includes, for example, a rectangular housing 15, and the inside of the housing 15 is divided into a machine room 201 and a ventilation room 202.

[0039] The machine room 201 houses the compressor 6 and other components, while the blower room 202 houses the heat exchanger 8 and the blower 9. The first heat exchanger 8a and the second heat exchanger 8b, which make up the heat exchanger 8, are arranged in an L-shape, for example, when viewed from above. The first heat exchanger 8a has its longitudinal direction along the y-direction, which is the left-right direction of the outdoor unit 2, and the second heat exchanger 8b has its longitudinal direction along the x-direction, which is the front-to-back direction of the outdoor unit 2. The first heat exchanger 8a and the second heat exchanger 8b are connected in series by connecting pipes 7 and are arranged non-parallel. The connecting pipes 7 are shown as solid lines, with the first upper header 82a and the second upper header 82b visible through them.

[0040] The second heat exchanger 8b of the heat exchanger 8 has the same configuration as the first heat exchanger 8a. That is, the second heat exchanger 8b comprises a plurality of second heat transfer tubes 81b, a second upper header 82b, and a second lower header 83b. The plurality of second heat transfer tubes 81b are an example of a second heat exchanger. The plurality of second heat transfer tubes 81b are arranged to extend along the z direction, which is perpendicular to the direction of gravity g, as with the plurality of first heat transfer tubes 81a. That is, the z direction is the direction of extension of the plurality of second heat transfer tubes 81b.

[0041] A partition member 8c is installed inside the space between the first heat exchanger 8a and the second heat exchanger 8b, for example, as a barrier to prevent airflow. The partition member 8c has a plate-shaped member that is bent into an L-shape when viewed from above. The partition member 8c is rectangular when viewed from the front and from the side. The partition member 8c blocks the space between the first heat exchanger 8a and the second heat exchanger 8b, and also between the first upper header 82a and the first lower header 83a, and between the second upper header 82b and the second lower header 83b. By providing the partition member 8c, air bypassing the heat exchanger 8 is suppressed, and the heat exchange efficiency can be improved. Depending on the arrangement of the first heat exchanger 8a and the second heat exchanger 8b, if the total surface area of ​​the first heat exchanger 8a and the total surface area of ​​the second heat exchanger 8b are close together, the partition member 8c can be omitted.

[0042] Incidentally, hereinafter, the plurality of first heat transfer tubes 81a and the plurality of second heat transfer tubes 81b may be collectively referred to as heat transfer tubes. Also, the first upper header 82a and the second upper header 82b may be collectively referred to as the upper header 82. Further, the first lower header 83a and the second lower header 83b may be collectively referred to as the lower header 83.

[0043] The blower 9 is interposed between the first heat exchanger 8a and the second heat exchanger 8b in the blower chamber 202. The blower 9 is, for example, a propeller fan. The outdoor air supplied by the blower 9 is divided and passes through the first heat exchanger 8a and the second heat exchanger 8b, and is blown out of the housing 15 as it is from the opening formed in the housing 15 without flowing to the other heat exchanger 8.

[0044] The type of the refrigerant flowing through the refrigerant pipe 5 is not particularly limited, and in the classification of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), a refrigerant having a flammability of 2L, 2, 1 or a toxicity of B may be adopted. For example, a single refrigerant such as R1234yf, R1234ze, R32, R290, or a mixed refrigerant of any two or more of these, or a mixed refrigerant of any of these and another refrigerant, a mixed refrigerant containing R1132(E), or a mixed refrigerant containing R1123 may be enclosed. Also, a mixed refrigerant such as R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, R459A may be enclosed. Note that a refrigerant having flammability or toxicity needs to immediately diffuse when leaked to lower the concentration of the refrigerant.

[0045] FIG. 7 is a top view of the heat exchanger 8 according to Embodiment 1 of the present disclosure. FIG. 8 is a front view of the heat exchanger 8 according to Embodiment 1 of the present disclosure. FIG. 9 is a side view of the heat exchanger 8 according to Embodiment 1 of the present disclosure.

[0046] As shown in FIGS. 7 to 9, the first heat exchanger 8a and the second heat exchanger 8b are connected by a connection pipe 7 having one end connected to the first connection pipe 803a of the first lower header 83a and the other end connected to the second connection pipe 803b of the second upper header 82b.

[0047] The first connection port 813a (see FIG. 4) to which the first connection pipe 803a is connected is formed in the first lower header 83a so as to open in the z direction, which is the extending direction of the plurality of first heat transfer pipes 81a. The second connection port 813b (see FIG. 5) to which the second connection pipe 803b is connected is formed in the first lower header 83a so as to open in the z direction, which is the extending direction of the plurality of second heat transfer pipes 81b. The first heat exchanger 8a and the second heat exchanger 8b are connected via the first connection pipe 803a, the connection pipe 7, and the second connection pipe 803b.

[0048] In the cross section perpendicular to the extending direction of the heat transfer pipes, the heat exchanger 8 has a configuration in which the second upper header 82b exists in the y direction, which is the extending direction of the first lower header 83a, or the first upper header 82a exists in the y direction, which is the extending direction of the second lower header 83b. Further, the first connection port 813a and the second connection port 813b open in the z direction in the first lower header 83a and the second upper header 82b, respectively, and both the first connection pipe 803a and the second connection pipe 803b are provided in the extending direction of the heat transfer pipes. Therefore, when both ends of the connection pipe 7 are connected to the first connection pipe 803a and the second connection pipe 803b, the connection pipe 7 can be displaced in the z direction, so that no space is required for arranging the connection pipe 7. As a result, it is not necessary to secure a space between the first heat exchanger 8a and the second heat exchanger 8b, and the first heat exchanger 8a and the second heat exchanger 8b can be arranged close to each other. Consequently, it becomes possible to reduce the size of the housing 15 of the outdoor unit 2 that houses the heat exchanger 8.

[0049] The region between the first upper header 82a and the first lower header 83a, and the region between the second upper header 82b and the second lower header 83b, can be divided into a first region and a second region. The first region is a region in which no heat transfer tubes are arranged and does not contribute to heat exchange. For example, since no heat transfer tubes are provided at both ends of the upper header 82 and the lower header 83 in the longitudinal direction, the region between both ends of the upper header 82 and the lower header 83 in the longitudinal direction constitutes the first region. When the first heat exchanger 8a and the second heat exchanger 8b are arranged adjacent to each other, the regions between both ends of the upper header 82 and the lower header 83 in the longitudinal direction are adjacent and form a single first region.

[0050] The second region is an area that contributes to heat exchange, in which multiple first heat transfer tubes 81a and multiple first fins 84a, or multiple second heat transfer tubes 81b and multiple second fins (not shown), are arranged. The projected area of ​​the second region is referred to as the front surface area of ​​the heat exchanger 8. Since both the first connecting tube 803a and the second connecting tube 803b are provided in the direction of extension of the heat transfer tubes, the first heat exchanger 8a and the second heat exchanger 8b can be brought closer together, thereby increasing the front surface area of ​​the heat exchanger 8 and improving the heat exchange efficiency.

[0051] When the heat exchanger 8 is operating as a condenser, the refrigerant flowing from the refrigerant piping 5 into the upper inlet / outlet pipe 802a of the first heat exchanger 8a flows into the first upper header 82a, where it is distributed to a plurality of first heat transfer tubes 81a and passes through the plurality of first heat transfer tubes 81a. The refrigerant flowing through the plurality of first heat transfer tubes 81a descends from the first upper header 82a towards the first lower header 83a.

[0052] The refrigerant flows from multiple first heat transfer tubes 81a into the first lower header 83a, where it merges. From the first lower header 83a, it flows out of the first heat exchanger 8a via the first connecting pipe 803a and circulates through the connecting pipe 7. The refrigerant that has flowed through the connecting pipe 7 flows into the second upper header 82b of the second heat exchanger 8b via the second connecting pipe 803b, where it is distributed and passes through multiple second heat transfer tubes 81b. The refrigerant flowing through the multiple second heat transfer tubes 81b descends from the second upper header 82b towards the second lower header 83b. The refrigerant flows from multiple second heat transfer tubes 81b into the second lower header 83b, where it merges, and then flows out of the second heat exchanger 8b via the lower inlet / outlet pipe 802b, returning to the refrigerant piping 5.

[0053] In this way, the connecting pipe 7 is configured to cause the refrigerant that has descended through the multiple first heat transfer tubes 81a to rise from the first lower header 83a towards the second upper header 82b, and to cause the multiple second heat transfer tubes 81b to descend and flow into the second lower header 83b. With the connecting pipe 7, the flow of refrigerant when it operates as a condenser is entirely downward, which makes it possible to create a situation where the condensed refrigerant flows downward without resisting gravity, thereby improving the heat exchange efficiency.

[0054] Figure 10 is a perspective view showing a first heat exchanger 8a according to a modification 1 of Embodiment 1 of the present disclosure. As shown in Figure 10, the first heat exchanger 8a can also be configured without a plurality of first fins 84a, i.e., it can be finless. In this case, the pressure loss when the airflow passes through the first heat exchanger 8a in the direction indicated by the white arrow W is reduced.

[0055] In the case of a finless heat exchanger 8a, no heat transfer members with the same function as fins are provided between the multiple first heat transfer tubes 81a. When fins are provided, the multiple first heat transfer tubes 81a are connected via the fins, but in the case of a finless heat exchanger, each of the multiple first heat transfer tubes 81a is provided independently without being connected to one another. Therefore, condensation water flowing through the multiple first heat transfer tubes 81a does not adhere to or accumulate on the fins, making it easier to discharge the condensation water.

[0056] Thus, when the first heat exchanger 8a is arranged vertically, for example, with multiple first heat transfer tubes 81a extending in the vertical z-direction, making it finless facilitates the discharge of condensation water.

[0057] Furthermore, the second heat exchanger 8b can also be finless. Alternatively, the first heat exchanger 8a may be provided with fins, while only the second heat exchanger 8b is finless. In addition, for example, a finless configuration can be adopted for a portion of the first heat exchanger 8a.

[0058] Figure 11 is a cross-sectional view showing the first heat transfer tubes 81a of a first heat exchanger 8a according to a modified example 2 of Embodiment 1 of the present disclosure. As shown in Figure 11, the plurality of first heat transfer tubes 81a may have a circular cross-sectional shape in a plane perpendicular to the z direction, that is, in the xy plane. The first heat exchanger 8a may be composed of a plurality of first heat transfer tubes 81a with a circular cross-sectional shape, and the second heat exchanger 8b may be composed of a plurality of second heat transfer tubes 81b that are flattened tubes.

[0059] Figure 12 is a cross-sectional view showing another example of the first heat transfer tube 81a of the first heat exchanger 8a according to modification 3 of Embodiment 1 of the present disclosure. As shown in Figure 12, the first heat transfer tube 81a has a flattened cross-sectional shape and has a projection 85a. The projection 85a is, for example, a plate-shaped member. The width of the projection 85a, that is, the thickness of the projection 85a, is relatively thin, for example, smaller than the width of the first heat transfer tube 81a. Therefore, heat is efficiently dissipated from the surface of the projection 85a, and the effect of promoting heat transfer can be achieved.

[0060] The projection 85a is provided on the windward and leeward sides of the first heat transfer tube 81a in the airflow direction. The projection 85a may be integrally molded with the first heat transfer tube 81a, or it may be joined to the first heat transfer tube 81a by brazing. The projection 85a is made of a thermally conductive metallic material. For example, aluminum, aluminum alloy, copper, or copper alloy can be used as the material constituting the projection 85a. The material of the projection 85a may be the same as or different from that of the first heat transfer tube 81a. The projection 85a extends in the airflow direction and along the longitudinal direction of the flattened tube. One end of the projection 85a is connected to the first heat transfer tube 81a, and the other end, which is the tip of the projection 85a, is a free end. The projection 85a is cantilevered to the first heat transfer tube 81a.

[0061] By providing the projection 85a on the first heat transfer tube 81a, the heat transfer area of ​​the first heat transfer tube 81a can be increased, further improving the heat exchange performance of the first heat exchanger 8a. The projection 85a may be provided only on either the upwind or downwind side. Furthermore, the projection 85a may be provided on both the first heat transfer tube 81a of the first heat exchanger 8a and the second heat transfer tube 81b of the second heat exchanger 8b, or on only one of them.

[0062] <Comparative Example> Figure 13 is a top view of the heat exchanger 8 according to the comparative example. Figure 14 is a front view of the heat exchanger 8 according to the comparative example. Figure 15 is a side view of the heat exchanger 8 according to the comparative example.

[0063] As shown in Figures 13 to 15, the first connecting pipe 803a of the first lower header 83a is positioned along the extension direction of the first lower header 83a, and the second connecting pipe 803b of the second upper header 82b is positioned along the extension direction of the second upper header 82b. In other words, the first connecting pipe 803a is positioned along the horizontal y-direction, and the second connecting pipe 803b is positioned along the horizontal x-direction. For this reason, space must be secured to allow the connecting pipes 7 to move horizontally, and a clearance must be provided between the first heat exchanger 8a and the second heat exchanger 8b.

[0064] The connecting pipe 7 extends from the first lower header 83a along the extension direction of the first lower header 83a, then extends in a vertical direction perpendicular to the extension direction, and then extends again along the extension direction of the second upper header 82b to connect to the second upper header 82b. As a result, the connecting pipe 7 has to be bent multiple times in order to connect the first heat exchanger 8a and the second heat exchanger 8b, making the structure and manufacturing of the heat exchanger 8 complicated.

[0065] When the first lower header 83a and the second upper header 82b are projected onto the xy plane, the second upper header 82b does not exist in the direction of extension of the first lower header 83a, and the first lower header 83a does not exist in the direction of extension of the second upper header 82b. The xy plane is a plane perpendicular to the direction of extension of the first heat transfer tube 81a and the second heat transfer tube 81b. In other words, in the configuration of Embodiment 1, the area in which the airflow could be blocked by the first heat exchanger 8a and the second heat exchanger 8b cannot be blocked in the configuration of the Comparative Example because a clearance is created between the first heat exchanger 8a and the second heat exchanger 8b. If the airflow cannot be blocked, the heat exchange efficiency decreases, so in order to maintain the heat exchange efficiency in the Comparative Example, it becomes necessary to extend the partition member 8c to that area, which increases the required amount of partition member 8c.

[0066] In contrast, in Embodiment 1, the first connecting pipe 803a and the second connecting pipe 803b are arranged in the z-direction, which is the extension direction of the heat transfer tube, in the second upper header 82b and the first lower header 83a, respectively. The first connecting pipe 803a and the second connecting pipe 803b extend from the second upper header 82b and the first lower header 83a in directions that are close to each other, allowing the connecting pipe 7 to move out of the way in the z-direction. As a result, there is no need to bend the connecting pipe 7 multiple times, and there is no need to provide clearance between the first heat exchanger 8a and the second heat exchanger 8b to accommodate the connecting pipe 7. Furthermore, the first heat exchanger 8a and the second heat exchanger 8b can be arranged such that, when the first lower header 83a and the second upper header 82b are projected onto the xy-plane, the second upper header 82b is located in the extension direction of the first lower header 83a. Alternatively, the first heat exchanger 8a and the second heat exchanger 8b can be arranged such that the first lower header 83a is located in the direction of extension of the second upper header 82b. As a result, it becomes possible to reduce the amount of partition member 8c required to block airflow between the first heat exchanger 8a and the second heat exchanger 8b, and ultimately, it becomes possible to eliminate the partition member 8c altogether.

[0067] The heat exchanger 8 according to Embodiment 1 described above has a first connecting pipe 803a positioned in the first lower header 83a in the direction of extension of the first heat transfer tube 81a, and a second connecting pipe 803b positioned in the second upper header 82b in the direction of extension of the second heat transfer tube 81b. The heat exchanger 8 includes, for example, a first heat exchanger 8a and a second heat exchanger 8b that are arranged non-parallel to each other, and the first heat exchanger 8a and the second heat exchanger 8b are connected in series by a connecting pipe 7. The configuration of the first connecting pipe 803a and the second connecting pipe 803b allows the connecting pipe 7 to be routed in the z direction, eliminating the need to bend the connecting pipe 7 multiple times. Furthermore, because the connecting pipe 7 can be routed in the z direction, the space required for arranging the connecting pipe 7, which would be necessary three-dimensionally if it were routed in a direction intersecting the extension direction, is not needed, and the need to bend the connecting pipe 7 multiple times is also eliminated. Therefore, in order to arrange the connecting pipes 7 between the first connecting pipe 8a and the second connecting pipe 803b, it is not necessary to provide a clearance between the first heat exchanger 8a and the second heat exchanger 8b, and the first heat exchanger 8a and the second heat exchanger 8b can be placed closer together. In addition, it becomes possible to miniaturize or eliminate the air leakage suppression member that was provided between the first heat exchanger 8a and the second heat exchanger 8b. As a result, the structure of the heat exchanger 8 can be rationalized, and the front surface area can be increased, while contributing to the miniaturization of the housing 15 in which the heat exchanger 8 is housed.

[0068] Furthermore, the first heat exchanger 8a and the second heat exchanger 8b can be arranged such that, when the first lower header 83a and the second upper header 82b are projected onto the xy plane, the second upper header 82b is located in the direction of extension of the first lower header 83a. Alternatively, the first heat exchanger 8a and the second heat exchanger 8b can be arranged such that the first lower header 83a is located in the direction of extension of the second upper header 82b. As a result, the area that can block the airflow by the first heat exchanger 8a and the second heat exchanger 8b, or the amount by which the components for blocking the airflow are reduced, increases. In addition, since the connecting pipe 7 is connected to the first connecting pipe 803a and the second connecting pipe 803b without being bent, the connection work is easy.

[0069] Furthermore, the refrigeration cycle device 1, including the heat exchanger 8, is configured such that when the heat exchanger 8 acts as a condenser, the refrigerant flowing inside descends through the first heat exchanger 8a, then rises through the connecting pipe 7, and then descends again through the second heat exchanger 8b. This allows the condensed refrigerant to flow downwards without resistance to gravity, thereby improving heat exchange efficiency.

[0070] Embodiment 2. Figure 16 is a top view of the heat exchanger 8 according to Embodiment 2 of the present disclosure. Figure 17 is a front view of the heat exchanger 8 according to Embodiment 2 of the present disclosure. Figure 18 is a side view of the heat exchanger 8 according to Embodiment 2 of the present disclosure. Embodiment 2 differs from Embodiment 1 in the positional relationship between the first lower header 83a and the second upper header 82b. In Embodiment 2, parts common to Embodiment 1 are denoted by the same reference numerals and their descriptions are omitted, and the differences from Embodiment 1 will be described in detail.

[0071] As shown in Figures 16 to 18, the first heat exchanger 8a and the second heat exchanger 8b are arranged such that when the first lower header 83a and the second upper header 82b are projected onto the xy plane, the first lower header 83a and the second upper header 82b partially overlap. The length of the first upper header 82a in the extension direction is shorter than the length of the first lower header 83a in the extension direction, and the length of the second upper header 82b in the extension direction is longer than the length of the second lower header 83b in the extension direction.

[0072] In a front view, the end of the first lower header 83a of the heat exchanger 8 protrudes beyond the end of the first upper header 82a, and in a side view, the end of the second upper header 82b protrudes beyond the end of the second lower header 83b. Furthermore, in a top view of the heat exchanger 8, a portion of the first lower header 83a overlaps with the second upper header 82b on the projection plane in the z direction. Moreover, when projected onto the xy plane, the first connecting pipe 803a and the second connecting pipe 803b are arranged closer together compared to the case of Embodiment 1.

[0073] This configuration reduces the first region, which is the area between the upper header 82 and the lower header 83 where no heat transfer tubes are arranged. As a result, the area between the first heat exchanger 8a and the second heat exchanger 8b that needs to be blocked by a blocking member is reduced, and the amount of blocking member required is reduced while maintaining heat exchange efficiency. In addition, the area in which the heat exchangers 8 are arranged in a limited space is increased, improving heat exchange performance.

[0074] Furthermore, the configuration in which the first connecting pipe 803a and the second connecting pipe 803b are close together when projected onto the xy plane allows the connecting pipe 7 to be connected to each of the first connecting pipe 803a and the second connecting pipe 803b without bending the connecting pipe 7. In addition, the configuration in which the first connecting pipe 803a and the second connecting pipe 803b are close together when projected onto the xy plane also shortens the travel distance of the connecting pipe 7.

[0075] As described above, the heat exchanger 8 according to Embodiment 2 has a first lower header 83a and a second upper header 82b that overlap in the field of view in the direction of extension of the heat transfer tubes, that is, when projected onto the xy plane. Therefore, it is possible to arrange the first heat exchanger 8a and the second heat exchanger 8b in closer proximity, and the amount by which the blocking region or blocking member for blocking the airflow, which is placed between the first heat exchanger 8a and the second heat exchanger 8b and obstructs the airflow, can be reduced can be increased. In addition, since the first connecting pipe 803a and the second connecting pipe 803b can be connected to each other by simply bending the connecting pipe 7 slightly, the connection between the first heat exchanger 8a and the second heat exchanger 8b by the connecting pipe 7 becomes easier.

[0076] Embodiment 3. Figure 19 is a top view of the heat exchanger 8 according to Embodiment 3 of the present disclosure. Figure 20 is a front view of the heat exchanger 8 according to Embodiment 3 of the present disclosure. Figure 21 is a side view of the heat exchanger 8 according to Embodiment 3 of the present disclosure. Embodiment 3 of the present disclosure differs from Embodiment 1 or 2 in the positional relationship between the first connecting pipe 803a and the second connecting pipe 803b. In Embodiment 3, parts common to Embodiment 1 or 2 are denoted by the same reference numerals and their descriptions are omitted, and the differences from Embodiment 1 or 2 will be described in detail.

[0077] As shown in Figures 19 to 21, the first heat exchanger 8a and the second heat exchanger 8b are arranged such that the first connecting pipe 803a and the second connecting pipe 803b overlap when projected onto the xy plane. In a front view of the heat exchanger 8, the end of the first lower header 83a in the extension direction extends beyond the end of the first upper header 82a to a position where it is flush with the side surface 80b of the second heat exchanger 8b. In a side view of the heat exchanger 8, the end of the second upper header 82b in the extension direction extends beyond the end of the second lower header 83b to a position where it is flush with the side surface 80a of the first heat exchanger 8a.

[0078] With this configuration, the connecting pipe 7 that connects the first heat exchanger 8a and the second heat exchanger 8b extends one-dimensionally in the z-direction, which is the extension direction of the heat transfer tube, and no regions are bent or curved. As a result, the structure of the connecting pipe 7 is simplified, and the connection work of the connecting pipe 7 in manufacturing becomes easier. In addition, the areas that need to be blocked by blocking members are further reduced, and heat exchange efficiency can be maintained while reducing the amount of blocking members required. Furthermore, the area in which the heat exchangers 8 can be arranged in a limited space is increased, and the heat exchange performance can be improved.

[0079] In the heat exchanger 8 according to Embodiment 3 described above, the connecting pipe 7 that connects the first heat exchanger 8a and the second heat exchanger 8b extends one-dimensionally in the z-direction, which is the direction of extension of the heat transfer tubes. Therefore, the structure of the connecting pipe 7 can be further simplified.

[0080] Embodiment 4. Figure 22 is a top view of the heat exchanger 8 according to Embodiment 4 of the present disclosure. Figure 23 is a front view of the heat exchanger 8 according to Embodiment 4 of the present disclosure. Figure 24 is a side view of the heat exchanger 8 according to Embodiment 4 of the present disclosure. Embodiment 4 differs from Embodiments 1 to 3 in the structure of the first heat exchanger 8a and the second heat exchanger 8b. In Embodiment 4, parts common to Embodiments 1 to 3 are denoted by the same reference numerals and their descriptions are omitted, and the differences from Embodiments 1 to 3 will be the focus of the description.

[0081] As shown in Figures 22 to 24, the heat exchanger 8 is configured such that, in a front view, the first heat exchanger 8a is point-symmetric with respect to the center, and in a side view, the second heat exchanger 8b is point-symmetric with respect to the center. In other words, the length of the first upper header 82a in the extension direction is equal to the length of the first lower header 83a in the extension direction, and the length of the second upper header 82b in the extension direction is also equal to the length of the second lower header 83b in the extension direction.

[0082] In a front view of the heat exchanger 8, the first upper header 82a and the first lower header 83a protrude in different directions in the extension direction, and in a side view, the end of the second upper header 82b and the end of the second lower header 83b protrude in different directions. Furthermore, in a top view of the heat exchanger 8, a portion of the first lower header 83a overlaps with the projection plane of the second upper header 82b in the z direction.

[0083] As a result, similar to Embodiment 3, the area that needs to be blocked by a blocking member between the first heat exchanger 8a and the second heat exchanger 8b is reduced, and the amount of blocking member required is reduced while maintaining heat exchange efficiency. In addition, the area in which the heat exchangers 8 are arranged in a limited space is increased, improving heat exchange performance. Furthermore, the upper header 82 and the lower header 83 can be made common, reducing the number of parts.

[0084] As described above, in the heat exchanger 8 according to Embodiment 4, at least one of the first heat exchanger 8a or the second heat exchanger 8b is point-symmetric with respect to the center. Therefore, it is possible to use the same upper header 82 and lower header 83, and the number of parts required for manufacturing the heat exchanger 8 can be reduced.

[0085] Embodiment 5. Figure 25 is a top view illustrating a method for manufacturing a heat exchanger 8 according to Embodiment 5 of the present disclosure. Figure 26 is a side view illustrating a method for manufacturing a heat exchanger 8 according to Embodiment 5 of the present disclosure. Embodiment 5 differs from Embodiments 1 to 4 in the configuration of the connecting piping 7. In Embodiment 5, parts common to Embodiments 1 to 4 are denoted by the same reference numerals and their descriptions are omitted, and the explanation will focus on the differences from Embodiments 1 to 4.

[0086] The manufacturing method for the heat exchanger 8 includes a joining step and a twisting step. In the joining step, as shown in Figures 25 and 26, first, the first upper header 82a and the first lower header 83a are joined to both ends of the plurality of first heat transfer tubes 81a, and the second upper header 82b and the second lower header 83b are joined to both ends of the plurality of second heat transfer tubes 81b. Furthermore, both ends of the connecting pipe 7 are joined to the first connecting pipe 803a and the second connecting pipe 803b, respectively. The connecting pipe 7 is joined to the first connecting pipe 803a and the second connecting pipe 803b by brazing at the same time that the heat transfer tubes 81 and the upper header 82 and the lower header 83 are joined by brazing. As a result, the first heat exchanger 8a and the second heat exchanger 8b are joined so that they are arranged in parallel.

[0087] Figure 27 is a top view illustrating a method for manufacturing a heat exchanger 8 according to Embodiment 5 of the present disclosure. Figure 27 shows a twisting step in the manufacturing method of the heat exchanger 8. As shown in Figure 27, the twisting step is a step of twisting the connecting pipe 7 in the direction of arrow A around the axial direction of the pipe so that the first heat exchanger 8a and the second heat exchanger 8b, which are arranged parallel to each other and joined together, become non-parallel. Specifically, the connecting pipe 7 is twisted and the second heat exchanger 8b is rotated along an arc-shaped trajectory centered on the connecting pipe 7 and bent so that it becomes non-parallel to the first heat exchanger 8a. With the connecting pipe 7 twisted, the first heat exchanger 8a and the second heat exchanger 8b are arranged non-parallel, and the heat exchanger 8 is housed in the casing 15 of the outdoor unit 2 in this state. The connecting pipe 7 can be made of aluminum, for example.

[0088] In this way, the desired structure can be achieved by simultaneously joining the connecting pipes 7 when brazing the heat transfer tubes of the heat exchanger 8 to the upper header 82 and the lower header 83. Furthermore, since the connecting pipes 7 are joined simultaneously to the upper header 82 and the lower header 83, the heat transfer tubes of the heat exchanger 8 and the upper header 82 and the lower header 83 are brazed by a torch, eliminating the need for further brazing afterward and simplifying the manufacturing process.

[0089] The partition member 8c may be attached to the first heat exchanger 8a and the second heat exchanger 8b separately during the joining process, or it may be attached as a single unit after the twisting process. In the configuration of Embodiment 5, due to the twisting process, it may be necessary to extend the partition member 8c to the area of ​​the upper header 82 or the lower header 83, but compared to the comparative example of Embodiment 1, the extent to which extension of the partition member 8c is required can be reduced.

[0090] As described above, the heat exchanger 8 according to Embodiment 5 is arranged so as to be non-parallel by twisting the connecting pipes 7. In the joining process, the heat transfer tubes are joined to the upper header 82 and the lower header 83, and in the subsequent twisting process, the connecting pipes 7 are twisted. Therefore, it is possible to join the connecting pipes 7 at the same time as brazing the heat transfer tubes to the upper header 82 and the lower header 83, respectively, eliminating the need for subsequent brazing with a torch and simplifying the manufacturing process.

[0091] Furthermore, embodiments 1 to 5 can be combined as appropriate.

[0092] 1 Refrigeration cycle unit, 2 Outdoor unit, 3 Indoor unit, 4 Refrigerant circuit, 5 Refrigerant piping, 6 Compressor, 7 Connecting piping, 8 Heat exchanger, 8a First heat exchanger, 8b Second heat exchanger, 8c Partition member, 9 Blower, 10 Expansion section, 11 Third heat exchanger, 12 Load-side blower, 13 Control device, 15 Housing, 80a End face, 80b End face, 81a First heat transfer tube, 81b Second heat transfer tube, 82 Upper header, 82a First upper header, 82b Second upper header, 83 Lower header, 83a First lower header, 83b Second lower header, 84a First fin, 85a Projection, 201 Machine room, 202 Blower room, 801 Heat transfer tube insertion hole, 802 Upper inlet / outlet pipe, 802a Upper inlet / outlet pipe, 802b Lower inlet / outlet pipe, 803 Lower inlet / outlet pipe, 803a First connecting pipe, 803b Second connecting pipe, 811a Internal flow path, 813a First connection port, 813b Second connection port.

Claims

1. A first heat exchanger comprising: a plurality of first heat transfer tubes arranged at intervals; a first upper header provided at one upper end of the plurality of first heat transfer tubes; a first lower header provided at one lower end of the plurality of first heat transfer tubes; a second heat exchanger comprising: a plurality of second heat transfer tubes arranged at intervals; a second upper header provided at one upper end of the plurality of second heat transfer tubes; a second lower header provided at one lower end of the plurality of second heat transfer tubes; and connecting piping connecting the first lower header of the first heat exchanger and the second upper header of the second heat exchanger, wherein a first connection port formed in the first lower header and to which the connecting piping is connected is provided on the extending side of the plurality of first heat transfer tubes. A heat exchanger in which a second connection port formed in the second upper header, to which the connecting pipe is connected, is provided on the extension direction side of the plurality of second heat transfer tubes.

2. The heat exchanger according to claim 1, wherein the first heat exchanger and the second heat exchanger are arranged such that the extension direction of the first lower header and the extension direction of the second upper header are not parallel.

3. The heat exchanger according to claim 1 or 2, wherein the first heat exchanger and the second heat exchanger are arranged such that, when the first lower header and the second upper header are projected onto a cross section perpendicular to the extension direction of the plurality of first heat transfer tubes and the plurality of second heat transfer tubes, the second upper header is located in the extension direction of the first lower header, or the first lower header is located in the extension direction of the second upper header.

4. The heat exchanger according to any one of claims 1 to 3, wherein the first lower header and the second upper header have overlapping portions in the field of view in the extension direction of the plurality of first heat transfer tubes and the plurality of second heat transfer tubes.

5. The heat exchanger according to any one of claims 1 to 4, wherein the connecting piping is one-dimensional.

6. The heat exchanger according to any one of claims 1 to 5, wherein the first lower header and the first upper header are point-symmetric with respect to the center of the first heat exchanger, or the second upper header and the second lower header are point-symmetric with respect to the center of the second heat exchanger.

7. The heat exchanger according to any one of claims 1 to 6, wherein the first heat exchanger and the second heat exchanger are arranged so as to be non-parallel by twisting the connecting pipe.

8. A method for manufacturing a heat exchanger according to any one of claims 1 to 7, comprising the steps of: joining the plurality of first heat transfer tubes, the first lower header, the connecting pipe, the second upper header, and the plurality of second heat transfer tubes while the first heat exchanger and the second heat exchanger are arranged in parallel; and twisting the connecting pipe so that the first heat exchanger and the second heat exchanger are not parallel.

9. A refrigeration cycle device comprising: a heat exchanger according to any one of claims 1 to 7; and a refrigerant circuit to which the heat exchanger is connected and a refrigerant circulates, wherein when the heat exchanger acts as a condenser, the refrigerant flowing through the heat exchanger descends the plurality of first heat transfer tubes, rises through the connecting pipes, and descends the plurality of second heat transfer tubes.

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