Heat exchanger

Abstract

To prevent a plurality of plate-like members from being stacked in a wrong stacking order when the plurality of plate-shaped members are stacked to form a header in which a branching flow passage is formed.SOLUTION: An outdoor heat exchanger 1 includes a plurality of heat transfer pipes 23 and an expansion valve side header 21 in which a branching flow passage that branches a refrigerant into the plurality of heat transfer pipes 23 is formed. The expansion valve side header 21 includes a plurality of plate-shaped members in which a branching flow passage forming element is formed. The branching flow passage is formed of the branching flow passage forming element by stacking the plurality of plate-shaped members. In the plurality of plate-shaped members, a plurality of identification portions 93 are respectively formed in regions different from the region in which the branching flow passage forming element is formed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a heat exchanger. [Background technology]

[0002] A heat exchanger is known in which a header is formed from a plurality of plate-shaped members, and in which shunt channels for shunting a refrigerant to a plurality of heat transfer tubes are formed (see Patent Document 1). The plurality of plate-shaped members are provided with shunt channel-forming elements, such as holes or slits, and the shunt channels are formed by stacking the plurality of plate-shaped members and connecting the shunt channel-forming elements. This heat exchanger can improve the strength and durability of the header. Furthermore, the shape of the shunt channels can be changed simply by changing the shape and size of the shunt channel-forming elements of some of the plurality of plate-shaped members, thereby improving design flexibility and reducing development and manufacturing costs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 073610 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in this type of heat exchanger, if the order or orientation of the multiple plate-like members is incorrect, the intended shunt flow path will not be formed inside the header, causing the refrigerant to be improperly diverted to the multiple heat transfer tubes, resulting in a deterioration in heat exchange performance, and in the worst case scenario, the shunt flow path will be blocked midway, preventing the refrigerant flow.

[0005] The disclosed technology has been developed in consideration of such points, and aims to provide a heat exchanger that prevents multiple plate-shaped members from being stacked in the wrong order when a header is formed in which multiple plate-shaped members are stacked to form a branch flow path inside. [Means for solving the problem]

[0006] A heat exchanger according to one aspect of the present disclosure comprises a plurality of heat transfer tubes and a header in which a branch channel is formed to branch a refrigerant to the plurality of heat transfer tubes, the header having a plurality of plate-shaped members in which branch channel forming elements are formed, the branch channel being formed from the branch channel forming elements by stacking the plurality of plate-shaped members, and each of the plurality of plate-shaped members having an identification portion indicative of the stacking order of the plurality of plate-shaped members formed in an area other than the area in which the branch channel forming elements are formed. [Effects of the Invention]

[0007] The disclosed heat exchanger can prevent multiple plate-shaped members from being stacked in the wrong order when a header is formed in which multiple plate-shaped members are stacked to form a branch flow path inside. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a refrigerant circuit diagram showing an air conditioner provided with a heat exchanger according to a first embodiment. [Figure 2] FIG. 2 is a front view showing the heat exchanger of the first embodiment. [Figure 3] FIG. 3 is a top view showing the heat exchanger of the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing a heat transfer tube of the heat exchanger of the first embodiment. [Figure 5] FIG. 5 is an exploded perspective view showing the internal structure of the expansion valve side header of the heat exchanger of the first embodiment. [Figure 6] FIG. 6 is a perspective view showing the other end of the expansion valve side header. [Figure 7] FIG. 7 is a diagram showing a jig used when assembling an expansion valve-side header, and a state in which a plurality of plate-like members are fitted into this jig, as viewed from the heat transfer tube-side plate-like member side. [Figure 8] FIG. 8 is a perspective view showing a plurality of plate-like members stacked using a jig. [Figure 9] FIG. 9 is a perspective view showing a plurality of identification parts when a plurality of plate-like members are stacked using a jig. [Figure 10] FIG. 10 is a perspective view of a main part of a plurality of plate-shaped members of a heat exchanger according to a second embodiment, as viewed from above in the header longitudinal direction. [Figure 11] FIG. 11 is a perspective view of a main part of the expansion valve-side header of the heat exchanger of the third embodiment, as viewed from below in the longitudinal direction of the header on the heat transfer tube-side plate-shaped member side. [Figure 12] FIG. 12 is a front view of the expansion valve side header of the heat exchanger of the fourth embodiment, as viewed from the heat transfer tube side plate member side. [Figure 13] FIG. 13 is a front view of the expansion valve side header of the heat exchanger of the fifth embodiment, as viewed from the heat transfer tube side plate member side. [Figure 14] FIG. 14 is a front view of each of the plurality of plate-shaped members of the heat exchanger of the sixth embodiment, as viewed from the introduction direction. [Figure 15] FIG. 15 is a front view of each of the plurality of plate-shaped members of the heat exchanger of the seventh embodiment, as viewed from the introduction direction. [Figure 16] FIG. 16 is a cross-sectional view showing a recess formed from an identification portion of a heat exchanger according to a seventh embodiment. [Figure 17] FIG. 17 is a side cross-sectional view of the expansion valve side header of the heat exchanger of the eighth embodiment, as viewed from the downwind end face side. [Figure 18] FIG. 18 is a perspective view showing a plurality of plate members of a heat exchanger according to an eighth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a heat exchanger according to an embodiment of the present disclosure will be described in detail with reference to the drawings. Note that the following description does not limit the technology of the present disclosure. In addition, in the following description, the same components are given the same reference numerals, and duplicated descriptions will be omitted. [Example]

[0010] As shown in Fig. 1, the heat exchanger of the first embodiment is an outdoor heat exchanger 1 provided in an air conditioner 10. Fig. 1 is a refrigerant circuit diagram of the air conditioner 10 provided with the outdoor heat exchanger 1 of the first embodiment. The air conditioner 10 includes an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 is installed outdoors. The indoor unit 3 is installed inside an indoor room.

[0011] The air conditioner 10 includes a refrigerant circuit 4. The refrigerant circuit 4 includes a compressor 5, a four-way valve 6, an indoor heat exchanger 7, an expansion valve 8, and an outdoor heat exchanger 1. The compressor 5 is disposed inside the outdoor unit 2. A suction pipe 11 and a discharge pipe 12 are connected to the compressor 5. The compressor 5 compresses the refrigerant sucked through the suction pipe 11 and discharges the compressed refrigerant to the discharge pipe 12.

[0012] The four-way valve 6 is disposed inside the outdoor unit 2. The four-way valve 6 is connected to a suction pipe 11 and a discharge pipe 12, is connected to the outdoor heat exchanger 1 via a refrigerant pipe 14, and is connected to the indoor heat exchanger 7 via a refrigerant pipe 15. The four-way valve 6 switches the refrigerant circuit 4 between a heating cycle and a cooling cycle. When the refrigerant circuit 4 is switched to the heating cycle, the discharge pipe 12 is connected to the indoor heat exchanger 7 via the four-way valve 6, and the suction pipe 11 is connected to the outdoor heat exchanger 1 via the four-way valve 6. When the refrigerant circuit 4 is switched to the cooling cycle, the discharge pipe 12 is connected to the outdoor heat exchanger 1 via the four-way valve 6, and the suction pipe 11 is connected to the indoor heat exchanger 7 via the four-way valve 6.

[0013] The indoor heat exchanger 7 is disposed inside the indoor unit 3. One refrigerant inlet and outlet of the indoor heat exchanger 7 is connected to the expansion valve 8 via refrigerant piping 16, and the other refrigerant inlet and outlet is connected to the four-way valve 6 via refrigerant piping 15 as described above. By rotating a fan (not shown), the indoor unit 3 passes air from the room in which the indoor unit 3 is installed through the indoor heat exchanger 7 to exchange heat with the refrigerant, and blows the air that has exchanged heat with the refrigerant into the room. The expansion valve 8 is disposed inside the outdoor unit 2. The expansion valve 8 is connected to the outdoor heat exchanger 1 via refrigerant piping 17. The air conditioner 10 adjusts the opening of the expansion valve 8 to adjust the amount of refrigerant flowing through the indoor heat exchanger 7 according to the air-conditioning capacity required by the indoor unit 3.

[0014] The outdoor unit 2 is equipped with an outdoor fan 18. The outdoor fan 18 is disposed inside the outdoor unit 2. The outdoor fan 18 blows outdoor air so that the air flows into a ventilation space 19 inside the outdoor unit 2. A ventilation direction 20 in which the air flows due to the outdoor fan 18 is approximately horizontal when the outdoor unit 2 is properly installed. The outdoor heat exchanger 1 is disposed inside the outdoor unit 2 and fixed to the outdoor unit 2 so that the air flowing through the ventilation space 19 passes through the outdoor heat exchanger 1. The outdoor heat exchanger 1 exchanges heat between the refrigerant flowing through the outdoor heat exchanger 1 and the air flowing through the ventilation space 19.

[0015] 2 is a front view showing the outdoor heat exchanger 1 of Example 1. The outdoor heat exchanger 1 includes an expansion valve side header 21 (header), a compressor side header 22, a plurality of heat transfer tubes 23, and a plurality of fins 24. The expansion valve side header 21 is formed in a cylindrical shape, and is disposed so that a header longitudinal direction 25, which is the extension direction of the expansion valve side header 21, is perpendicular to the bottom surface of the outdoor unit 2 (not shown), and is fixed to the outdoor unit 2. A refrigerant pipe 17 is connected to the expansion valve side header 21, and an expansion valve 8 is connected via the refrigerant pipe 17.

[0016] The compressor side header 22 is formed in a columnar shape, is arranged so that the extension direction of the compressor side header 22 is parallel to the header longitudinal direction 25, and is fixed to the outdoor unit 2. A flow dividing space is formed inside the compressor side header 22. The refrigerant piping 14 is connected to the compressor side header 22 so that the four-way valve 6 is connected to the flow dividing space via the refrigerant piping 14.

[0017] The heat transfer tubes 23 are arranged at equal intervals in the header longitudinal direction 25 as shown in FIG. 2 . One end of each of the heat transfer tubes 23 is connected to the expansion valve side header 21. The other end of each of the heat transfer tubes 23 is connected to the compressor side header 22. The heat transfer tubes 23 are fixed to the expansion valve side header 21 and the compressor side header 22 by connecting both ends of the heat transfer tubes 23 to the expansion valve side header 21 and the compressor side header 22, respectively, and the outdoor heat exchanger 1 is fixed to the outdoor unit 2 by the expansion valve side header 21 and the compressor side header 22. In the following description, the extension direction of the heat transfer tubes 23 as shown in FIG. 2 is defined as a heat transfer tube longitudinal direction 26. This heat transfer tube longitudinal direction 26 is a direction perpendicular to the header longitudinal direction 25.

[0018] Each of the fins 24 is formed in a flat plate shape. Fig. 3 is a top view showing the outdoor heat exchanger 1 of the first embodiment. The fins 24 are arranged perpendicular to the heat transfer tube longitudinal direction 26 (parallel to the ventilation direction 20) and are aligned at equal intervals in the heat transfer tube longitudinal direction 26. The fins 24 are fixed to the heat transfer tubes 23 so as to be thermally connected to them.

[0019] Each of the plurality of heat transfer tubes 23 is formed in a flat shape, as shown in Fig. 4. Fig. 4 is a cross-sectional view of the heat transfer tube 23 of the outdoor heat exchanger 1 of the first embodiment. A plurality of flow paths 33 are formed inside the heat transfer tube 23 and aligned in the ventilation direction 20. The other ends of the plurality of heat transfer tubes 23 are connected to the compressor-side header 22, so that the plurality of flow paths 33 are connected to the flow branch space of the compressor-side header 22.

[0020] 5 is an exploded perspective view showing the internal structure of the expansion valve side header 21 of the outdoor heat exchanger 1 of the first embodiment. The expansion valve side header 21 includes a plurality of plate-like members 71 to 76 that are all rectangular in shape. The plurality of plate-like members 71 to 76 are stacked and joined to one another, with the stacking direction being approximately parallel to the heat transfer tube longitudinal direction 26. The plurality of plate-like members 71 to 76 include a refrigerant piping side plate-like member 71, a heat transfer tube side plate-like member 72, a plurality of circulation flow path plate-like members 73, a plurality of return flow path plate-like members 74, a plurality of insertion space plate-like members 75, and an introduction hole plate-like member 76. 5, the plate-like members are stacked in the following order from upstream to downstream in the introduction direction 48 (the direction in which refrigerant flows in the outdoor heat exchanger 1 when the outdoor heat exchanger 1 functions as an evaporator): refrigerant piping side plate-like member 71, multiple return flow path plate-like members 74, multiple circulation flow path plate-like members 73, introduction hole plate-like member 76, multiple insertion space plate-like members 75, and heat transfer tube side plate-like member 72. In the following description, when referring to the multiple return flow path plate-like members 74, the multiple circulation flow path plate-like members 73, and the multiple insertion space plate-like members 75 formed by the multiple plate-like members 71 to 76, the word "multiple" may be omitted when referring to a combination of the multiple plate-like members 71 to 76 joined together.

[0021] The circulation flow path plate-shaped members 73 are formed to have the same shape (in this Example 1, the three circulation flow path plate-shaped members 73 shown in FIG. 5 have the same shape). The return flow path plate-shaped member 74 is disposed between the circulation flow path plate-shaped member 73 and the refrigerant pipe side plate-shaped member 71. The insertion space plate-shaped members 75 are formed to have the same shape (in this Example 1, the three insertion space plate-shaped members 75 shown in FIG. 5 have the same shape). The insertion space plate-shaped member 75 is disposed between the introduction hole plate-shaped member 76 and the heat transfer tube side plate-shaped member 72. The introduction hole plate-shaped member 76 is disposed between the circulation flow path plate-shaped member 73 and the insertion space plate-shaped member 75.

[0022] In the following description, the end face of the lower end of the expansion valve side header 21 in the header longitudinal direction 25 will be referred to as one end 41, and the end face of the upper end of the expansion valve side header 21 opposite the one end 41 will be referred to as the other end 42.

[0023] The expansion valve-side header 21 is formed by stacking the above-described plate-like members in the order of refrigerant pipe-side plate member 71, return flow path plate member 74, circulation flow path plate member 73, introduction hole plate member 76, insertion space plate member 75, and heat transfer tube-side plate member 72 from upstream to downstream in the introduction direction 48, thereby forming a branch flow path within the expansion valve-side header 21. The branch flow path includes an inlet space 43, a refrigerant pipe through-hole 44, a circulation flow path 45, an inlet 61, a plurality of insertion spaces 46, a plurality of heat transfer tube through-holes 47, and a plurality of introduction holes 62. The inlet space 43 is located in a region within the expansion valve-side header 21 close to the one end 41. The inlet space 43 is formed from inlet space holes 83 (branch flow path forming elements) formed in each circulation flow path plate member 73.

[0024] The refrigerant piping through-hole 44 is formed by a refrigerant piping hole 77 formed in the refrigerant piping side plate-like member 71 and a refrigerant piping hole 78 formed in the return flow path plate-like member 74. Therefore, the refrigerant piping through-hole 44 is disposed on the upstream side of the inflow space 43 in the introducing direction 48. The refrigerant piping 17 passes through the refrigerant piping through-hole 44, and the inflow space 43 is connected to the expansion valve 8 via the refrigerant piping 17.

[0025] The circulation flow path 45 is formed by a circulation flow path plate-shaped member 73 and a turn-back flow path plate-shaped member 74, and includes a first flow path 57, a second flow path 58, a first turn-back flow path 51, and a second turn-back flow path 52. The first flow path 57 is formed from first flow path holes 84 (branch flow path forming elements) formed in a plurality of the circulation flow path plate-shaped members 73. The second flow path 58 is formed from second flow path holes 85 (branch flow path forming elements) formed in a plurality of the circulation flow path plate-shaped members 73. Therefore, the first flow path 57 and the second flow path 58 are aligned with the inflow space 43 in the header longitudinal direction 25 and are located above the inflow space 43. The first flow path 57 is formed along a straight line parallel to the header longitudinal direction 25. The second flow path 58 is located upwind of the first flow path 57 in the ventilation direction 20 and is formed along another straight line parallel to the header longitudinal direction 25.

[0026] The first turn flow path 51 is formed by first turn flow path holes 81 (branch flow path forming elements) formed in the plurality of turn flow path plate-shaped members 74, and turns the refrigerant flowing through the first flow path 57 back to the second flow path 58. That is, the direction in which the refrigerant flows through the first turn flow path 51 is perpendicular to the introduction direction 48 and parallel to the ventilation direction 20. The second turn flow path 52 is formed by second turn flow path holes 82 (branch flow path forming elements) formed in the plurality of turn flow path plate-shaped members 74, and turns the refrigerant flowing through the second flow path 58 back to the first flow path 57. That is, the direction in which the refrigerant flows through the second turn flow path 52 is perpendicular to the introduction direction 48 and parallel to the ventilation direction 20. Therefore, the first turn flow path 51 and the second turn flow path 52 are aligned in the header longitudinal direction 25 and are disposed upstream of the first flow path 57 and the second flow path 58 in the introduction direction 48. The first turning flow path 51 is formed in a region close to the other end 42, and is connected to the upper end of the first flow path 57 and the upper end of the second flow path 58. The second turning flow path 52 is formed in a lower region close to the one end 41, and is connected to the lower end of the first flow path 57 and the lower end of the second flow path 58.

[0027] The width dimension of the first turning flow path 51 in the ventilation direction 20 is equal to the width of the second turning flow path 52 in the ventilation direction 20. On the other hand, the width dimension of the first turning flow path 51 in the header longitudinal direction 25 is larger than the width of the second turning flow path 52 in the ventilation direction 20. Therefore, the flow path cross-sectional area of ​​the first turning flow path 51 when viewed from the introduction direction 48 is larger than the flow path cross-sectional area of ​​the second turning flow path 52 when viewed from the introduction direction 48.

[0028] The inlet 61 is formed from an inlet hole 86 (branch flow path forming element) formed in the plurality of circulation flow path plate-shaped members 73. Therefore, the inlet 61 is disposed between the inflow space 43 and the first flow path 57, and the refrigerant that has flowed into the inlet 61 flows into the first flow path 57 via the inlet 61.

[0029] The multiple insertion spaces 46 are formed by communication between multiple insertion space holes 87 (branch flow path forming elements) formed in the multiple insertion space plate-shaped members 75. Therefore, the multiple insertion spaces 46 are arranged downstream in the introduction direction 48 as viewed from the area where the inflow space 43 and the circulation flow path 45 are arranged, and are lined up in the header longitudinal direction 25. In this embodiment, seven of the multiple insertion spaces 46 from the top are upper insertion spaces 68, and the remaining one is the bottommost insertion space 53. The bottommost insertion space 53 is arranged below the multiple upper insertion spaces 68 and is arranged at the bottom of the multiple insertion spaces 46. The volume of the bottommost insertion space 53 is larger than the volume of each of the multiple upper insertion spaces 68 and is the largest of the multiple insertion spaces 46. The volumes of the multiple upper insertion spaces 68 are generally equal to each other.

[0030] The heat transfer tube through holes 47 are formed in the heat transfer tube side plate member 72. Therefore, the heat transfer tube through holes 47 are arranged downstream in the introduction direction 48 as seen from the insertion spaces 46, and are aligned at equal intervals in the header longitudinal direction 25. In this embodiment, of the heat transfer tube through holes 47, seven heat transfer tube through holes 47 counting from the top are defined as upper heat transfer tube through holes 67, and the remaining two heat transfer tube through holes 47 are defined as bottom-most heat transfer tube through holes 54. The two bottom-most heat transfer tube through holes 54 are positioned below the upper heat transfer tube through holes 67, i.e., they are positioned at the lowest of the heat transfer tube through holes 47 and are positioned downstream in the introduction direction 48 as seen from the inflow space 43.

[0031] Burrings (not shown) are formed on the heat transfer tube side plate-like member 72. When the heat transfer tube through-holes 47 are formed in the heat transfer tube side plate-like member 72, the burrings are formed so as to protrude upstream in the introduction direction 48 from the edges of the heat transfer tube holes. As a result, when the plurality of plate-like members 71 to 76 are appropriately stacked, the burrings are disposed in the plurality of insertion spaces 46. Each heat transfer tube 23 is inserted into each heat transfer tube through-hole 47 and welded to the burring of each heat transfer tube through-hole 47 (for example, by melting a layer of brazing material previously provided on the surface of the heat transfer tube 23 with heat), thereby firmly fixing the plurality of heat transfer tubes 23 to the expansion valve side header 21.

[0032] One end of a heat transfer tube 23 connected to a corresponding upper heat transfer tube through-hole 67 is disposed in each upper insertion space 68. Meanwhile, one end of each of two heat transfer tubes 23 connected to the two lowest heat transfer tube through-holes 54 is disposed in the lowest insertion space 53. By disposing the ends of the heat transfer tubes 23 in the insertion spaces 46, the insertion spaces 46 communicate with the flow paths 33 formed inside each heat transfer tube 23.

[0033] The multiple introduction holes 62 are formed in the introduction hole plate member 76. Therefore, the multiple introduction holes 62 are aligned in the header longitudinal direction 25 and are respectively disposed between the first flow passages 57 and the multiple insertion spaces 46. The multiple insertion spaces 46 and the first flow passages 57 are connected by the multiple introduction holes 62.

[0034] In this embodiment, the seven introduction holes 62 from the top are upper introduction holes 65, and the remaining one is a bottom-most introduction hole 64. The bottom-most introduction hole 64 is disposed below the multiple upper introduction holes 65. The lower end region 59 of the first flow path 57 and the bottom-most insertion space 53 are connected by the bottom-most introduction hole 64. The first flow path 57 and the multiple upper insertion spaces 68 are connected by the multiple upper introduction holes 65.

[0035] The cross-sectional flow area of ​​the plurality of upper inlet holes 65 increases as the inlet hole is positioned higher. The cross-sectional flow area of ​​the lowest inlet hole 64 is smaller than the cross-sectional flow area of ​​the second inlet hole 66, which is positioned lowermost among the plurality of upper inlet holes 65.

[0036] Fig. 6 is a perspective view showing the other end 42 of the expansion valve side header 21. In Fig. 6 and subsequent figures, a plurality of circulation flow path plate-shaped members 73 are depicted on a single plate-shaped member, a plurality of return flow path plate-shaped members 74 are depicted on a single plate-shaped member, and a plurality of insertion space plate-shaped members 75 are depicted on a single plate-shaped member. Each of the plurality of plate-shaped members 71 to 76 formed in the expansion valve side header 21 has an identification portion 93 formed on the upper end surface (end surface) formed at the other end 42. The identification portion 93 is formed so as to protrude from the other end 42, and in this embodiment, the identification portion 93 is a protruding portion having an arc-shaped outline as shown in Fig. 6. The identification portions 93 formed on each of the plurality of plate-shaped members 71-76 are provided in different positions on each of the plurality of plate-shaped members 71-76. When the plate-shaped members 71-76 are stacked in the correct stacking order, top and bottom, or back and forth, the plurality of identification portions 93 are arranged in a regular pattern along a straight line 95 shown in FIG. 6 . By providing the identification portions 93 on each of the plate-shaped members 71-76 in this manner, it is possible to easily check whether the order in which the plurality of plate-shaped members 71-76 are stacked is correct. That is, when the plurality of plate-shaped members 71-76 are stacked correctly, the plurality of identification portions 93 are regularly aligned along the straight line 96. When the stacking order is incorrect or when any of the plurality of plate-shaped members 71-76 are stacked upside down or back to front, they are not aligned along the straight line 95 or some of the plurality of identification portions 93 are missing. This makes it possible to determine at a glance whether the plurality of plate-shaped members 71-76 are stacked correctly. As mentioned above, since the plate-like members 71 to 76 are all the same shape, it is easy to confuse the stacking order or the top and bottom or front and back, and if the stacking order or the top and bottom or front and back is mistaken, the shunt paths formed by the stacking of the plate-like members 71 to 76 will be blocked midway or unintended shunt paths will be formed. In this embodiment, by providing each of the plate-like members 71 to 76 with an identification portion 93 to prevent confusion in the stacking order, the intended shunt paths will be reliably formed.

[0037] When forming the identifiers 93 on the plate-like members 71-76, it is preferable to maximize the distance between the shunt channels formed by stacking multiple plate-like members 71-76 and the identifiers 93. For example, the distance between the shunt channels and the identifiers 93 should be at least 1.5 times the thickness of the plate-like members 71-76. If possible, the identifiers 93 should be formed at the farthest point from the shunt channels on each plate-like member 71-76. If the distance between the shunt channels and each identifier 93 is less than 1.5 times the thickness of the plate-like members 71-76, the shunt channels may be disconnected or the identifiers 93 or the shunt channel-forming elements may be deformed during the formation of the plate-like members 71-76, for example, when drilling or cutting to form the shunt channel-forming elements after the identifiers 93 are formed. To prevent such problems, it is preferable to maximize the distance between the shunt channels and the identifiers 93, preferably at least 1.5 times the thickness of the plate-like members 71-76.

[0038] When assembling the expansion valve side header 21 by stacking and joining multiple plate-like members 71-76, a jig 101 such as that shown in FIG. 7 is used. FIG. 7 is a diagram of the jig 101 used when assembling the expansion valve side header 21, and the state in which the multiple plate-like members 71-76 are fitted into this jig 101, as viewed from the side of the heat transfer tube side plate-like member 72. Each of the multiple plate-like members 71-76 further has an upwind end face 103 and a downwind end face 104. Here, the upwind end face 103 is the upwind end face in the ventilation direction 20 of the expansion valve side header 21 formed by stacking the multiple plate-like members 71-76. The downwind end face 104 is the downwind end face in the ventilation direction 20 of the expansion valve side header 21 formed by stacking the multiple plate-like members 71-76.

[0039] The jig 101 includes an upwind side surface facing portion 105 against which the upwind end faces 103 of each of the plate-like members 71 to 76 abut, a downwind side surface facing portion 106 against which the downwind end faces 104 of each of the plate-like members 71 to 76 abut, and a one end portion facing portion 107 against which one end portion 41 of each of the plate-like members 71 to 76 abuts. When assembling the expansion valve side header 21, the multiple plate-like members 71 to 76 are placed inside the jig 101 with the one end portions 41 abutting against the one end portion facing portion 107, the upwind end faces 103 abutting against the upwind side surface facing portion 105, and the downwind end faces 104 abutting against the downwind side surface facing portion 106. In this way, the plate-like members 71 to 76 are stacked in the correct order and with their positions aligned, by placing the three end faces of each of the plate-like members 71 to 76 that do not have the identification features 93 against the jig 101 and stacking the plate-like members 71 to 76 so that the identification features 93 are regularly aligned. When the plate-like members 71 to 76 are properly arranged inside the jig 101 in this way, the other end 42 is positioned in a location of the jig 101 where there is no wall, and each identification feature 93 is exposed from the jig 101, as shown in FIG.

[0040] As described above, because the other end 42 is exposed from the jig 101, the arrangement of the plurality of identifiers 93 when the plurality of plate-like members 71 to 76 are stacked using the jig 101 can be visually confirmed as shown in Fig. 9, and visual confirmation makes it easy to confirm whether the arrangement of the identifiers 93 is regularly arranged (for example, on a straight line 95 in Fig. 6). In this case, if the plurality of identifiers 93 are not regularly arranged, it is determined that the plurality of plate-like members 71 to 76 are not stacked correctly, and the plurality of plate-like members 71 to 76 can be rearranged so that the plurality of identifiers 93 are regularly arranged, and then the plate-like members 71 to 76 can be placed in a high-temperature furnace with the jig 101 fitted thereon to join the respective plate-like members 71 to 76, for example.

[0041] As described above, when assembling the expansion valve side header 21 of this embodiment, it is easy to determine by looking at the identification portion 93 whether the plate-like members 71 to 76 have been stacked correctly, so it is possible to prevent the plate-like members 71 to 76 from being stacked or joined in the wrong stacking order or with the top and bottom or front and back facing up and down, and to prevent the unintended formation of branch paths or the branch paths being severed midway.

[0042] Furthermore, since the expansion valve side header 21 is formed by stacking multiple plate-like members 71 to 76, changes to the refrigerant flow path in the expansion valve side header 21 or changes to the number of joined heat transfer tubes 23 can be accommodated simply by changing any of the plate-like members. This improves the design flexibility of the outdoor heat exchanger 1 including the expansion valve side header 21 and reduces development and manufacturing costs.

[0043] For example, the outdoor heat exchanger 1 can easily adjust the volumes of the first turn-back flow path 51 and the second turn-back flow path 52 by changing the number of the plurality of turn-back flow path plate-shaped members 74, without changing the shapes of the first turn-back flow path holes 81 and the second turn-back flow path holes 82 of the plurality of turn-back flow path plate-shaped members 74. The outdoor heat exchanger 1 can easily adjust the volumes of the first flow path 57 and the second flow path 58 by changing the number of the plurality of circulation flow path plate-shaped members 73, without changing the shapes of the first flow path holes 84 and the second flow path holes 85 of the plurality of circulation flow path plate-shaped members 73. The outdoor heat exchanger 1 can easily adjust the volumes of the plurality of insertion spaces 46 by changing the number of the plurality of insertion space plate-shaped members 75, without changing the shapes of the plurality of insertion space holes 87 of the plurality of insertion space plate-shaped members 75.

[0044] The air conditioner 10 can perform heating and cooling operations as described below. [Heating operation] The heating operation is performed, for example, when the air conditioner 10 is operated by a user to perform the heating operation. When the air conditioner 10 performs the heating operation, the four-way valve 6 switches the refrigerant circuit 4 to the heating cycle. The compressor 5 compresses the low-pressure gas-phase refrigerant that flows from the four-way valve 6 into the suction pipe 11. The low-pressure gas-phase refrigerant is compressed by the compressor 5 to become high-pressure gas-phase refrigerant. The compressor 5 discharges the high-pressure gas-phase refrigerant into the discharge pipe 12. The high-pressure gas-phase refrigerant discharged into the discharge pipe 12 flows into the indoor heat exchanger 7 via the four-way valve 6 because the refrigerant circuit 4 has been switched to the heating cycle.

[0045] The indoor unit 3 passes air from the room in which the indoor unit 3 is installed through the indoor heat exchanger 7. The indoor heat exchanger 7 exchanges heat between the high-pressure gas-phase refrigerant that has flowed into the indoor heat exchanger 7 and the air passing through the indoor heat exchanger 7, cooling the high-pressure gas-phase refrigerant that has flowed into the indoor heat exchanger 7 and heating the air passing through the indoor heat exchanger 7. The indoor unit 3 blows the air heated by the indoor heat exchanger 7 into the room in which the indoor unit 3 is installed, heating the room. The high-pressure gas-phase refrigerant is cooled and condensed in the indoor heat exchanger 7, becoming a supercooled high-pressure liquid-phase refrigerant. In other words, the indoor heat exchanger 7 functions as a condenser when the air conditioner 10 performs heating operation. The high-pressure liquid-phase refrigerant flows out of the indoor heat exchanger 7 and flows into the expansion valve 8.

[0046] Expansion valve 8 reduces the pressure of the high-pressure liquid-phase refrigerant that has flowed into expansion valve 8. The high-pressure liquid-phase refrigerant is reduced in pressure by expansion valve 8 and becomes a low-pressure gas-liquid two-phase refrigerant. The low-pressure gas-liquid two-phase refrigerant flows out of expansion valve 8 and flows into refrigerant piping 17. Outdoor fan 18 flows outdoor air into ventilation space 19.

[0047] The low-pressure gas-liquid two-phase refrigerant flowing through the refrigerant pipe 17 flows into the inlet space 43 of the expansion valve-side header 21 through the refrigerant pipe through-hole 44. The low-pressure gas-liquid two-phase refrigerant that has flowed into the inlet space 43 further flows into the lower end region 59 of the first flow passage 57 through the inlet 61. The low-pressure gas-liquid two-phase refrigerant that has flowed into the lower end region 59 through the inlet 61 flows toward the other end 42 in the header longitudinal direction 25 and rises along the first flow passage 57. At this time, the refrigerant is diverted from the first flow passage 57 to each of the introduction holes 62. The remaining gas-liquid two-phase refrigerant that has flowed through the first flow passage 57 and reached the upper end region 60 of the first flow passage 57 (other than the diverted refrigerant that has flowed into each of the introduction holes 62) flows into the second flow passage 58 through the first return flow passage 51. The low-pressure gas-liquid two-phase refrigerant that has flowed into the second flow passage 58 descends along the second flow passage 58.

[0048] The liquid refrigerant of the low-pressure gas-liquid two-phase refrigerant that has descended along the second flow path 58 flows from the second flow path 58 into the lower end region 59 of the first flow path 57 via the second turning flow path 52. The liquid refrigerant that has flowed into the lower end region 59 via the second turning flow path 52 rises along the first flow path 57 together with the low-pressure gas-liquid two-phase refrigerant that has flowed into the lower end region 59 via the inlet 61. That is, during heating operation, the low-pressure gas-liquid two-phase refrigerant that has flowed into the circulation flow path 45 circulates through the circulation flow path 45. Circulating the low-pressure gas-liquid two-phase refrigerant through the circulation flow path 45 suppresses imbalance of the liquid refrigerant of the low-pressure gas-liquid two-phase refrigerant in the circulation flow path 45.

[0049] The low-pressure gas-liquid two-phase refrigerant flowing upward along the first flow path 57 flows into each of the insertion spaces 46 via the multiple introduction holes 62. At this time, the liquid refrigerant of the low-pressure gas-liquid two-phase refrigerant rising along the first flow path 57 is pushed toward the four corners of the first flow path 57 by gas refrigerant, which has a lower specific gravity than the liquid refrigerant, flowing through the center of the first flow path 57, and then flows through these four corners and rises up the first flow path 57. As a result, some of the liquid refrigerant flows into and stagnates in an upper end region 60 of the first flow path 57 without being diverted to the multiple insertion spaces 46. When the low-pressure gas-liquid two-phase refrigerant rises along the first flow path 57, when the refrigerant circulation rate in the refrigerant circuit 4 is high and a large amount of refrigerant flows into the expansion valve side header 21, the amount of liquid refrigerant of the low-pressure gas-liquid two-phase refrigerant stagnates in the upper end region 60 of the first flow path 57 more than when the refrigerant circulation rate is low and a small amount of refrigerant flows into the expansion valve side header 21. That is, the amount of liquid refrigerant stagnating in the upper end region 60 of the first flow path 57 increases in proportion to the amount of refrigerant flowing into the expansion valve side header 21. In the expansion valve side header 21 of the first embodiment, the liquid refrigerant that reaches the upper end region 60 of the first flow path 57 flows through the first return flow path 51 to the second flow path 58, and then flows from the second flow path 58 through the second return flow path 52 to the first flow path 57 again. That is, while the liquid refrigerant is circulated between the first flow path 57 and the second flow path 58, the refrigerant is diverted from the first flow path 57 to each heat transfer tube 23 through the introduction holes 62 and the insertion spaces 46. Therefore, it is possible to prevent the liquid refrigerant from stagnating in the upper end region 60 of the first flow path 57 inside the expansion valve side header 21, and therefore it is possible to prevent the refrigerant from drifting from the expansion valve side header 21 to each heat transfer tube 23 due to the liquid refrigerant stagnating in the expansion valve side header 21.

[0050] The low-pressure gas-liquid two-phase refrigerant flows through the first flow path 57 from bottom to top and into each of the inlet holes 62. Therefore, in the first flow path 57, the flow rate of the low-pressure gas-liquid two-phase refrigerant decreases toward the upper side in the header longitudinal direction 25. Furthermore, in the expansion valve side header 21, as in this embodiment, the smaller the refrigerant circulation rate of the low-pressure gas-liquid two-phase refrigerant circulating through the circulation flow path 45, the smaller the flow velocity of the low-pressure gas-liquid two-phase refrigerant flowing into the first flow path 57 through the inlet 61. This makes it more difficult for the liquid refrigerant in the low-pressure gas-liquid two-phase refrigerant to reach the upper side of the first flow path 57, and the liquid refrigerant accumulates below the first flow path 57. At this time, the flow rate of the liquid refrigerant flowing from the first flow path 57 into the multiple insertion spaces 46 through the multiple inlet holes 62 decreases toward the upper side and increases toward the lower side. This causes uneven flow of the liquid refrigerant flowing through the heat transfer tubes 23.

[0051] In the expansion valve-side header 21 of the first embodiment, the flow path cross-sectional areas of the multiple inlet holes 62 are increased toward the upper side, so that the flow path resistance of the multiple inlet holes 62 decreases toward the upper side. Therefore, when the refrigerant flows upward through the first flow paths 57 and is diverted into each insertion space 46, the resistance the refrigerant encounters as it flows into each insertion space 46 decreases toward the upper side. As a result, the amount of refrigerant flowing from a lower inlet hole 62 to the corresponding insertion space 46 is smaller than the amount of refrigerant flowing from the immediately upper inlet hole 62 to the corresponding insertion space 46. In other words, the amount of low-pressure gas-liquid two-phase refrigerant flowing from each inlet hole 62 to each inlet hole 62 increases toward the upper side. Therefore, even when the flow rate of the liquid refrigerant ascending along the first flow paths 57 described above is unevenly distributed so that it becomes smaller toward the upper side, the uneven distribution of the liquid refrigerant among the heat transfer tubes 23 is reduced and the amounts of the liquid refrigerant are generally equalized.

[0052] The refrigerant flowing in from the refrigerant piping through-hole 44 and the refrigerant flowing in from the second return flow path 52 combine in the lower end region 59 of the first flow path 57, and the refrigerant flows in through the inlet 61. As a result, the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing in the lower end region 59 of the first flow path 57 is greater than the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing in the first flow path 57 other than the lower end region 59. Therefore, the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing into the lowest-stage insertion space 53 is greater than the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing into the plurality of upper insertion spaces 68. Furthermore, if the low-pressure gas-liquid two-phase refrigerant that has flowed into the lowest-stage insertion space 53 is directed to one heat transfer tube, the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing through this one heat transfer tube may be greater than the flow rates of the low-pressure gas-liquid two-phase refrigerant flowing in the other heat transfer tubes.

[0053] By inserting the lower two heat transfer tubes of the plurality of heat transfer tubes 23 into the lowest stage insertion space 53, the low-pressure gas-liquid two-phase refrigerant that flows into the lowest stage insertion space 53 is diverted to the two lower heat transfer tubes and flows into the plurality of flow paths 33 of the two lower heat transfer tubes. As a result, even when the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing into the lowest stage insertion space 53 is high, the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing through each of the two lower heat transfer tubes connected to the lowest stage insertion space 53 approaches the flow rate of the low-pressure gas-liquid two-phase refrigerant flowing through the other heat transfer tubes, improving the divergence of the low-pressure gas-liquid two-phase refrigerant among the plurality of heat transfer tubes 23.

[0054] The low-pressure gas-liquid two-phase refrigerant that has flowed into the multiple insertion spaces 46 flows into the multiple flow paths 33 formed inside the multiple heat transfer tubes 23 and flows toward the compressor-side header 22. The low-pressure gas-liquid two-phase refrigerant flowing through the multiple heat transfer tubes 23 exchanges heat with the air flowing through the ventilation space 19, is heated, and evaporates, becoming low-pressure gas-phase refrigerant. In other words, the outdoor heat exchanger 1 functions as an evaporator when the air conditioner 10 performs heating operation. The outdoor heat exchanger 1 of the first embodiment can suppress uneven flow of the liquid refrigerant among the multiple low-pressure gas-liquid two-phase refrigerants flowing through the multiple heat transfer tubes 23. In other words, the heat exchange performance is improved by improving the separation of the refrigerant flow in each heat transfer tube 23. The low-pressure gas-phase refrigerant flows out of the multiple heat transfer tubes 23 and merges in the compressor-side header 22. The low-pressure gas-phase refrigerant flowing out from the compressor side header 22 flows into the four-way valve 6 via the refrigerant piping 14, and because the refrigerant circuit 4 is switched to the heating cycle, it flows into the suction pipe 11 of the compressor 5 via the four-way valve 6.

[0055] [Cooling operation] When the air conditioner 10 is operated by a user to perform cooling operation, the four-way valve 6 is switched so that the refrigerant circuit 4 is in the cooling cycle. The compressor 5 compresses the low-pressure gas-phase refrigerant drawn in from the four-way valve 6 through the suction pipe 11. The low-pressure gas-phase refrigerant is compressed by the compressor 5 to become high-pressure gas-phase refrigerant, which is then discharged to the discharge pipe 12. Because the refrigerant circuit 4 has been switched to the cooling cycle, the high-pressure gas-phase refrigerant discharged to the discharge pipe 12 flows into the outdoor heat exchanger 1 via the four-way valve 6 and the refrigerant piping 14.

[0056] The high-pressure gas-phase refrigerant that flows into the outdoor heat exchanger 1 flows into the compressor-side header 22 and is diverted to the multiple heat transfer tubes 23. The high-pressure gas-phase refrigerant diverted to the multiple heat transfer tubes 23 exchanges heat with air flowing through the ventilation space 19 due to the rotation of the outdoor fan 18, condenses, and becomes a supercooled high-pressure liquid-phase refrigerant. In other words, the outdoor heat exchanger 1 functions as a condenser when the air conditioner 10 performs cooling operation. The high-pressure liquid-phase refrigerant flows out of the multiple heat transfer tubes 23 and into the multiple insertion spaces 46 of the expansion valve-side header 21. The high-pressure liquid-phase refrigerant that flows into the multiple insertion spaces 46 flows into the first flow path 57 of the circulation flow path 45 through the multiple introduction holes 62 and merges there. The high-pressure liquid-phase refrigerant that merges in the first flow path 57 flows into the refrigerant pipe 17 through the inlet 61, the inlet space 43, and the refrigerant pipe through-hole 44, flows through the refrigerant pipe 17, and flows into the expansion valve 8.

[0057] The high-pressure liquid-phase refrigerant that flows into the expansion valve 8 is decompressed to become a low-pressure two-phase gas-liquid refrigerant. This refrigerant then flows out of the expansion valve 8, through the refrigerant pipe 16, and into the indoor heat exchanger 7. The low-pressure two-phase gas-liquid refrigerant that flows into the indoor heat exchanger 7 exchanges heat with room air drawn into the indoor unit 3 by the rotation of the indoor fan (not shown). This causes the air passing through the indoor heat exchanger 7 to be cooled by the low-pressure two-phase gas-liquid refrigerant that flows into the indoor heat exchanger 7, and the cooled air is blown into the room where the indoor unit 3 is installed, thereby cooling the room. Meanwhile, the low-pressure two-phase gas-liquid refrigerant that flows into the indoor heat exchanger 7 is heated and evaporated in the indoor heat exchanger 7 to become a low-pressure gas-phase refrigerant. In other words, the indoor heat exchanger 7 functions as an evaporator when the air conditioner 10 performs cooling operation. The low-pressure gas-phase refrigerant that flows out of the indoor heat exchanger 7 flows sequentially through the refrigerant pipe 15, the four-way valve 6, and the suction pipe 11, before being drawn into the compressor 5 and compressed again.

[0058] Because the outdoor heat exchanger 1 functions as an evaporator when the air conditioner 10 is in heating operation, condensation may also occur in the expansion valve side header 21, and the condensation may cause condensed water to accumulate at the other end 42 of the expansion valve side header 21. When condensed water accumulates at the other end 42 of the expansion valve side header 21, if the other end 42 is formed with an upwardly protruding identifier 93 as in this embodiment, the condensed water formed at the identifier 93 flows downward along the identifier 93, thereby reducing the amount of condensed water that accumulates at the other end 42 of the expansion valve side header 21 compared to when the identifier 93 is not present at the other end 42. This prevents rust from forming at the other end 42 of the expansion valve side header 21 due to the accumulation of condensed water.

[0059] [Effects of the heat exchanger of Example 1] The heat exchanger of the first embodiment includes a plurality of heat transfer tubes 23 and an expansion valve-side header 21 in which a shunt channel is formed, which shunts refrigerant to the plurality of heat transfer tubes 23. The expansion valve-side header 21 is formed with a plurality of plate-shaped members 71-76, each having a shunt channel-forming element. By properly stacking the plurality of plate-shaped members 71-76, the shunt channel-forming elements are connected to each other, thereby forming a shunt channel. Each of the plurality of plate-shaped members 71-76 has an identifier 93 formed in an area other than the area in which the shunt channel-forming element is formed. When the plurality of plate-shaped members 71-76 are stacked, the identifiers 93 can be used to easily check whether the stacking order, top / bottom, and front / back of the plurality of plate-shaped members 71-76 are correct. Therefore, the heat exchanger of the first embodiment can prevent the shunt channel from being blocked midway or an unintended shunt channel from being formed, which would be caused by improperly stacking the plurality of plate-shaped members 71-76 in the wrong order, top / bottom, or front / back.

[0060] Furthermore, the identifier 93 in Example 1 is provided in each of the plate-like members 71 to 76 at a position away from the shunt flow path forming element, i.e., the shunt flow path, at a distance greater than 1.5 times the thickness of the plate-like member, and is preferably provided at a position farthest from the shunt flow path (the other end 42 in Example 1). By arranging the identifier 93 in this manner, when forming the shunt flow path forming element in each of the plate-like members 71 to 76, it is possible to prevent the shunt flow path and the identifier 93 from being disconnected, and to prevent the identifier 93 and the shunt flow path forming element from being deformed.

[0061] Furthermore, the multiple identification portions 93 of the heat exchanger of Example 1 are formed so as not to overlap in the stacking direction in which the multiple plate-like members 71 to 76 are stacked, and so as to line up regularly (along the straight line 95 in FIG. 6 ) when the plate-like members 71 to 76 are stacked without error. As a result, when the multiple plate-like members 71 to 76 are stacked to form the expansion valve side header 21, it is possible to easily check whether the multiple plate-like members 71 to 76 are stacked correctly by visually checking whether the multiple identification portions 93 are lined up regularly.

[0062] Furthermore, the plurality of identification portions 93 of the heat exchanger of Example 1 protrude from the upper end surface of the expansion valve side header 21 on the side of the other end 42. In this case, when the heat exchanger of Example 1 functions as an evaporator and condensation occurs on the upper end surface of the expansion valve side header 21, the condensed water formed on the identification portions 93 flows downward along the identification portions 93. Therefore, compared to a case where the identification portions 93 are not provided, it is possible to prevent condensed water from accumulating on the upper end surface of the expansion valve side header 21, and to prevent rust caused by condensed water from occurring on the upper end surface.

[0063] Furthermore, an identification portion 93 is formed on the other end portion 42 of each of the plate-shaped members 71 to 76 of the heat exchanger of Example 1. When stacking the multiple plate-shaped members 71 to 76, a jig 101 is used to align the positions of the multiple plate-shaped members 71 to 76, as shown in Figures 7 to 9. This way, when stacking the plate-shaped members 71 to 76 by bringing the end portion other than the other end portion 42 into contact with the jig 101, it is possible to visually check the identification portions 93 with the multiple plate-shaped members 71 to 76 fitted into the jig 101 and confirm that the multiple plate-shaped members 71 to 76 have been stacked correctly. [Example]

[0064] Fig. 10 is a perspective view of essential parts of a plurality of plate-shaped members 71 to 76 of a heat exchanger according to a second embodiment, viewed from above in the header longitudinal direction 25. As shown in Fig. 10, the heat exchanger according to the second embodiment is configured such that the identification features 93 of the plurality of plate-shaped members 71 to 76 of the heat exchanger according to the first embodiment described above are replaced with identification features 112. The configuration of the heat exchanger other than the identification features 112 is the same as that of the first embodiment.

[0065] Each of the plurality of identifiers 112 is formed on the other end 42 of each of the plurality of plate-like members 71-76, and is formed so as to be concave from the other end 42 toward the inside of each plate-like member. The plurality of identifiers 112 are formed so that the depth of the concaves is equal to one another. The plurality of identifiers 112 are formed at different positions on each of the plate-like members 71-76 so that, when the plurality of plate-like members 71-76 are stacked, the plurality of identifiers 112 are aligned along a straight line 113 and so that the interiors of the concaves are connected. Here, the straight line 113 is parallel to the plane along which the other end 42 of the expansion valve side header 21 lies and is a direction that intersects with the stacking direction.

[0066] When stacking and joining the plurality of plate-like members 71 to 76, as in the heat exchanger of Example 1 described above, by visually checking the arrangement of the respective identifiers 112 and confirming whether the respective identifiers 112 are regularly aligned along the straight lines 113, it is possible to easily determine whether the order in which the plurality of plate-like members 71 to 76 are stacked or whether the top and bottom or front and back are incorrect. That is, in the heat exchanger of Example 2, by visually checking the arrangement of the plurality of identifiers 112, it is possible to prevent the plurality of plate-like members 71 to 76 from being stacked in the wrong order or with the wrong top and bottom or front and back. Furthermore, when the heat exchanger functions as an evaporator and condensation occurs in the expansion valve side header 21, condensation also occurs inside the recesses of the identifiers 112. However, because the interiors of the recesses of the plurality of identifiers 112 are connected, the condensation inside the identifiers 112 flows through the interiors of the recesses of the identifiers 112 and out of the identifiers 112. Specifically, the condensed water inside the identification portion 112 flows out from each of the identification portions 112 of the refrigerant pipe side plate member 71 and the heat transfer tube side plate member 72, which are arranged at both ends in the introduction direction 48. Therefore, even if the identification portion 112 is provided with an inwardly concave shape as in the second embodiment, it is possible to prevent the condensed water from remaining on the identification portion 112 and to prevent the expansion valve side header 21 from rusting due to the condensed water. [Example]

[0067] 11 is a perspective view of a main portion of the expansion valve-side header 21 of the heat exchanger of Example 3, as viewed from below in the header longitudinal direction 25 on the heat transfer tube-side plate-like member 72 side. As shown in FIG. 11 , the heat exchanger of Example 3 is provided with an identification portion 132 instead of the identification portion 93 of Example 1 or the identification portion 112 of Example 2. The configuration of the heat exchanger other than the identification portion 132 is the same as in Example 1 or Example 2.

[0068] Unlike the identifier 93 of Example 1 and the identifier 112 of Example 2, the multiple identifiers 132 of this example are not provided at the other end 42 of the multiple plate-like members 71-76, but are provided at one end 41 of the multiple plate-like members 71-76 and are formed so as to be concave inward from the one end 41. The multiple identifiers 132 are formed at different positions on each of the plate-like members 71-76 so that, when the multiple plate-like members 71-76 are stacked, the multiple identifiers 132 are aligned along a straight line 133. Here, the straight line 133 is parallel to a plane along which the one end 41 of the expansion valve side header 21 lies and is a direction that intersects with the stacking direction.

[0069] When stacking and joining the plurality of plate-shaped members 71 to 76, as in the heat exchangers of Examples 1 and 2 described above, by visually checking the arrangement of the respective identifiers 132 and confirming whether the respective identifiers 132 are regularly aligned along the straight lines 133, it is possible to easily determine whether the order in which the plurality of plate-shaped members 71 to 76 are stacked or whether the top and bottom or front and back are incorrect. That is, in the heat exchanger of Example 3, by visually checking the arrangement of the plurality of identifiers 132, it is possible to prevent the plurality of plate-shaped members 71 to 76 from being stacked in the wrong order or with the wrong top and bottom or front and back. Furthermore, when the heat exchanger functions as an evaporator and condensation occurs in the expansion valve side header 21, because the identifier 132 is provided at the one end 41 that faces downward when the heat exchanger is installed, condensation does not accumulate even if the identifier 132 has an inwardly concave shape, thereby preventing rust due to condensation from forming in the expansion valve side header 21. [Example]

[0070] Fig. 12 is a front view of the expansion valve-side header 21 of the heat exchanger of Example 4, as viewed from the side of the heat transfer tube-side plate-shaped member 72. As shown in Fig. 12, the heat exchanger of Example 4 is provided with an identification part 142 instead of each of the identification parts 93 of Examples 1 to 3. The configuration of the heat exchanger other than the identification part 142 is the same as that of Examples 1 to 3.

[0071] An identifier 142 is formed on the other end 42 of each of the multiple plate-shaped members 71-76. Each of the multiple identifiers 142 has a bottom surface 143 and a step surface 144. The identifier 142 is formed by cutting out a rectangular portion of each of the plate-shaped members 71-76 on the other end 42 side, and the end faces resulting from the cutting out are the bottom surface 143 and the step surface 144. When forming the identifier 142 on each of the plate-shaped members 71-76, the area of ​​the rectangular shape cut out varies for each of the plate-shaped members 71-76. Specifically, when the plate-shaped members 71-76 are stacked correctly (in the order shown in FIG. 5 ), the area of ​​the rectangular shape cut out on the other end 42 side of each of the plate-shaped members 71-76 decreases from the heat transfer tube side plate-shaped member 72 toward the refrigerant pipe side plate-shaped member 71.

[0072] By forming the identifiers 142 on each of the plate-shaped members 71-76 as described above, when the plate-shaped members 71-76 are stacked correctly, the identifiers 142 are aligned regularly as viewed from the heat-transfer-tube-side plate-shaped member 72. Specifically, the step surfaces 144 of the identifiers 142 are aligned regularly along the airflow direction 20. If the plate-shaped members 71-76 are stacked in the wrong order, the identifier 142 of the plate-shaped member that is incorrectly positioned on the front side (the heat-transfer-tube-side plate-shaped member 72 side) obscures the step surfaces 144 of the plate-shaped member positioned further back, making it easy to confirm that the stacking order is incorrect. If the plate-shaped members 71-76 are stacked upside down, the step surfaces 144 of the plate-shaped member that is incorrectly positioned will move toward the downwind end face 104, resulting in the step surfaces 144 being arranged discontinuously like missing teeth, making it easy to confirm that the tops and bottoms are incorrect. If the top and bottom of each plate-like member 71 to 76 are mistaken when stacked, the plate-like member with the wrong top and bottom does not have an identification part 142 on the end face opposite the wrong plate-like member, and therefore the identification parts 142 of all plate-like members arranged further back than the wrong plate-like member will be hidden and cannot be seen, making it easy to confirm that the top and bottom are wrong. [Example]

[0073] Fig. 13 is a front view of the expansion valve-side header 21 of the heat exchanger of Example 5, as viewed from the side of the heat transfer tube-side plate-shaped member 72. As shown in Fig. 13, the heat exchanger of Example 5 is provided with an identification portion 152 instead of each of the identification portions 142 of Example 4. The configuration of the heat exchanger other than the identification portion 152 is the same as that of Example 4.

[0074] An identification portion 152 is formed on the other end 42 of each of the plurality of plate-like members 71 to 76. Each of the plurality of identification portions 152 has an inclined surface 153, and is formed by obliquely cutting off a corner on the other end 42 side of each of the plate-like members 71 to 76 (in FIG. 13, a corner on the downwind end face 104 side), and the end face resulting from the cutting is the inclined surface 153. When forming the identification portion 152 on each of the plate-shaped members 71 to 76, the area to be cut off diagonally is made different for each of the plate-shaped members 71 to 76. Specifically, when the plate-shaped members 71 to 76 are stacked correctly (in the order shown in Figure 5), the corners of the other end 42 are cut off so that the angle of the inclined surface 153 of each of the plate-shaped members 71 to 76 (i.e., the angle between the inclined surface 153 and the leeward end face 104) decreases from the plate-shaped member 72 on the heat transfer tube side toward the plate-shaped member 71 on the refrigerant piping side; in other words, the area to be cut off diagonally becomes smaller.

[0075] By forming the identifiers 152 on each of the plate-shaped members 71-76 as described above, when the plate-shaped members 71-76 are stacked correctly, the identifiers 152 are aligned regularly as viewed from the heat-transfer-tube-side plate-shaped member 72. Specifically, the identifiers 152 are aligned so that the angles of the inclined surfaces 153 of the identifiers 142 gradually decrease. If the stacking order is incorrect when stacking the plate-shaped members 71-76, the identifier 152 of the plate-shaped member incorrectly placed on the front side (the heat-transfer-tube-side plate-shaped member 72) obscures the inclined surfaces 153 of the plate-shaped member positioned further back, causing the angles of the inclined surfaces 153 to decrease discontinuously, making it easy to confirm that the stacking order is incorrect. If the plate-shaped members 71-76 are stacked upside down, the inclined surfaces 153 of the incorrectly placed plate-shaped member will be positioned on the windward end face 103 side, making it easy to confirm that the stacking order is incorrect. If the top and bottom of each plate-like member 71 to 76 are mistaken when stacked, the plate-like member with the wrong top and bottom does not have an identification part 152 on the end face opposite the wrong plate-like member, and therefore the identification parts 152 of all plate-like members arranged further back than the wrong plate-like member will be hidden and cannot be seen, making it easy to confirm that the top and bottom are wrong. [Example]

[0076] 14 is a front view of each of the plurality of plate-shaped members 71 to 76 of the heat exchanger of Example 6, as viewed from the introduction direction 48. As shown in Fig. 14, the heat exchanger of Example 6 is configured such that the identifiers 93 of the plurality of plate-shaped members 71 to 76 of the heat exchanger of Example 1 described above are replaced with identifiers 162. The configuration of the heat exchanger other than the identifiers 162 is the same as that of Example 1.

[0077] Each of the plurality of identifiers 162 is formed on the other end 42 of each of the plate-shaped members 71 to 76, and is formed so as to be concave from the other end 42 toward the inside. The number of identifiers 162 provided on each of the plate-shaped members 71 to 76 is different from one another. For example, the heat transfer tube side plate member 72 shown in Fig. 5 is provided with one identifier 162 as shown in the left diagram of Fig. 14, and the insertion space plate member 75 is provided with two identifiers 162 as shown in the left diagram of Fig. 14. In this way, the number of identifiers 162 provided can be increased toward the refrigerant pipe side plate member 71 in the introducing direction 48.

[0078] When stacking the plate-shaped members 71-76, visually counting the number of identifiers 162 on each of the plate-shaped members 71-76 from the other end 42 side makes it easy to confirm whether the plate-shaped members 71-76 are stacked in the correct order. For example, if the number of identifiers 162 increases from the heat transfer tube side plate-shaped member 72 toward the refrigerant pipe side plate-shaped member 71 as described above, if the stacking order of the plate-shaped members 71-76 is incorrect, there will be locations where the number of identifiers 162 decreases, making it easy to confirm that the stacking order is incorrect. Furthermore, if the plate-shaped members 71-76 are stacked upside down, the identifiers 162 will disappear midway because the opposite end face of the incorrectly stacked plate-shaped member does not have an identifier 162, making it easy to confirm that the upside down is incorrect.

[0079] In the above-described heat exchanger plate members 71 to 76 of Examples 1 to 6, an identification portion is provided on the end face of each plate member, and the identification portion is formed so as to protrude from the end face or to be recessed inward. However, as will be described in the following examples, an identification portion may be provided on the surface of each plate member (a surface other than the end face, such as a surface that overlaps with an adjacent plate member or a surface that is open to the outside). [Example]

[0080] Fig. 15 is a front view of each of the plurality of plate-like members 71 to 76 of the heat exchanger of Example 7, as viewed from the introduction direction 48. As shown in Fig. 15, the heat exchanger of Example 7 is configured such that the identifiers of the heat exchangers of Examples 1 to 6 described above are replaced with an identifier 182. The configuration of the heat exchanger other than the identifier 162 is the same as that of Example 1.

[0081] Each of the identifiers 182 in Example 7 is a hole that penetrates each plate-shaped member in the stacking direction, and is provided, for example, at a corner on the windward end face 103 side and the other end 42 side, as shown in FIG. 15 . The sizes of the identifiers 182 are different among the plate-shaped members 71 to 76. Specifically, when the plate-shaped members are stacked in the order from the heat-transfer-tube-side plate-shaped member 72 to the refrigerant-pipe-side plate-shaped member 71 as shown in FIG. 5 , the identifier 182 provided on the heat-transfer-tube-side plate-shaped member 72 is the largest hole (as depicted on the left side of FIG. 15 ), and the identifiers 182 become smaller toward the refrigerant-pipe-side plate-shaped member 71 (as depicted in the center and right side of FIG. 15 ). When the plate-shaped members 71 to 76 are provided with an identifier 182 in this way and stacked in the correct order, each identifier 182 is formed as a recess, as shown in the cross-sectional view of the vicinity of the identifier 182 on the right side of FIG. 16 . That is, the multiple identification features 182 are formed so that the holes are connected to one another and the size of the holes decreases in the stacking direction (from the heat transfer tube side plate member 72 to the refrigerant pipe side plate member 71). In the following description, the depression formed by stacking the identification features 182 is referred to as depression 183.

[0082] When stacking the multiple plate-shaped members 71 to 76, a jig 184 shown in FIG. 16 can be used to easily check whether the multiple plate-shaped members 71 to 76 are stacked in the correct order. The jig 184 is formed to fit into the recess 183, and if the multiple plate-shaped members 71 to 76 are stacked in the correct order, the jig 184 will fit into the recess 183. However, if the multiple plate-shaped members 71 to 76 are not stacked correctly, the shape of the recess 183 will differ from the shape shown in FIG. 16 and the jig 184 will not fit. Therefore, by determining whether the jig 184 fits into the recess 183, it is easy to determine whether the multiple plate-shaped members 71 to 76 are stacked correctly. For example, if the stacking order is incorrect when stacking the multiple plate-shaped members 71 to 76, the shape of the recess 183 will suddenly become smaller halfway through, causing the jig 184 to get stuck there and prevent it from fitting, making it easy to confirm that the stacking order is incorrect. Furthermore, if the top and bottom or front and back are mistaken when stacking multiple plate-like members 71 to 76, the plate-like member with the wrong top and bottom will not have an identification portion 182 at a location corresponding to the location where the identification portion 182 of the other plate-like member is to be placed, so the recess 183 will close midway and the jig 184 will get stuck there and will not fit together, making it easy to confirm that the top and bottom or front and back are wrong when stacking. [Example]

[0083] 17 is a side cross-sectional view of the expansion valve side header 21 of the heat exchanger of Example 8, viewed from the downwind end surface 104. As shown in Fig. 17, the heat exchanger of Example 8 is similar to Example 8 in that the identification portion 182 of the heat exchanger of Example 7 is replaced with an identification portion 192. The configuration of the heat exchanger other than the identification portion 194 is the same as that of Example 8.

[0084] As shown in FIG. 18 , the identifiers 192 are provided, for example, at corners on the windward end face 103 side and the other end 42 side, by processing the surface of each plate-like member 71-76 so as to be convex in the stacking direction (from the heat transfer tube side plate-like member 72 to the refrigerant pipe side plate-like member 71). By forming the identifiers 192 in this manner, as shown in FIG. 17 , the identifiers 192 are formed with convex portions 193 protruding in the stacking direction and concave portions 194 on their rear surfaces. The identifiers 192 formed on the multiple plate-like members 71-76 are formed so as to become larger as they proceed in the stacking direction toward the refrigerant pipe side plate-like member 71. Specifically, the identifiers 192 of each plate-like member are formed so that the convex portions 193 of the identifiers 192 of one plate-like member fit into the concave portions 194 of the identifiers 192 of the plate-like member stacked on top of that plate-like member. By forming the identifiers 192 in this manner, when the plate members 71 to 76 are stacked in the correct order, the identifiers 192 of adjacent plate members all fit together as shown in FIG.

[0085] When stacking multiple plate-shaped members 71-76, it is easy to confirm whether the multiple plate-shaped members 71-76 are stacked in the correct order by checking whether the identifiers 192 of each plate-shaped member 71-76 are fitted together. If the multiple plate-shaped members 71-76 are stacked in the correct order, all of the identifiers 192 will fit together, as shown in FIG. 17 . However, if the multiple plate-shaped members 71-76 are stacked incorrectly, some of the identifiers 192 will not fit together. Therefore, by determining whether the identifiers 192 fit together, it is easy to determine whether the multiple plate-shaped members 71-76 are stacked correctly. For example, if the stacking order is incorrect when stacking multiple plate-shaped members 71-76, the concave portion 194 of one identifier 192 will not fit into the convex portion 193 of the other identifier 192, making it easy to confirm that the stacking order is incorrect. Furthermore, if the top and bottom or front and back are mistaken when stacking multiple plate-like members 71 to 76, the identification portion 192 on the plate-like member that has been mistaken will come into contact with the surface of another plate-like member on which no identification portion 192 is provided, causing the plate-like members to float and not adhere to each other, making it easy to confirm that the top and bottom or front and back are wrong when stacking.

[0086] Although the embodiments have been described above, the embodiments are not limited to the above content. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, at least one of various omissions, substitutions, and modifications of the components can be made without departing from the spirit of the embodiments. [Explanation of symbols]

[0087] 1: Outdoor heat exchanger (heat exchanger) 21: Expansion valve side header (header) 23: Multiple heat transfer tubes 43:Inflow space (division channel) 45: Circulation channel (branch channel) 46: Multiple insertion spaces (branch channels) 61:Inlet (branch channel) 62: Multiple inlet holes (branch channels) 71 to 76: Multiple plate-shaped members 81: First return flow path hole (branch flow path forming element) 82: Second return flow path hole (branch flow path forming element) 83: Inflow space hole (division channel forming element) 84: First flow path hole (branch flow path forming element) 85: Second flow path hole (branch flow path forming element) 86: Inlet hole (separate channel forming element) 87: Multiple insertion space holes (branch flow path forming elements) 93: Multiple identification units 101: Jig 112: Multiple identification units 113: Straight line 132: Multiple identification units 133: Straight line 142: Multiple identification units 152: Multiple identification units 162: Multiple identification units 182: Multiple identification units 184: Jig 192: Multiple identification units

Claims

1. A plurality of heat transfer tubes; a header having a branch flow path formed therein for branching the refrigerant to the plurality of heat transfer tubes, the header has a plurality of plate-like members on which branch flow path forming elements are formed, the branch flow path is formed from the branch flow path forming element by stacking the plurality of plate-like members, Each of the plurality of plate-like members has an identification portion that indicates the stacking order of the plurality of plate-like members in a region different from a region where the branch flow path forming element is formed. heat exchanger.

2. The identification portion of each of the plurality of plate-like members is formed at a location spaced a predetermined distance from the branch path. The heat exchanger of claim 1 .

3. The predetermined distance is greater than 1.5 times the thickness of the plurality of plate-like members.

3. The heat exchanger of claim 2.

4. The identification portion is formed at a portion farthest from the branch path.

3. The heat exchanger of claim 2.

5. The identification portions are formed so as not to overlap in the stacking direction in which the plurality of plate-like members are stacked. The heat exchanger of claim 1 .

6. the identification portions are formed on end surfaces of the plurality of plate-like members, The end faces on which the identification portions are formed are the same among the end faces of the plurality of plate-shaped members. The heat exchanger of claim 1 .

7. The identification portion protrudes from the end surface.

7. The heat exchanger of claim 6.

8. The header is disposed vertically to an installation surface on which the outdoor unit is installed, The identification portion is formed on the end surface of the header that is closest to the installation surface.

7. The heat exchanger of claim 6.

9. the plurality of plate-like members are aligned by a portion of each of the plurality of plate-like members contacting a jig; The identification portion is formed at a location of the plurality of plate-like members that does not come into contact with the jig.

7. The heat exchanger of claim 6.

10. When the plurality of plate-shaped members are stacked, one of two adjacent plate-shaped members has a protruding portion that protrudes in the stacking direction of the plurality of plate-shaped members, The other of the two plate-shaped members has a fitting portion formed thereon that fits into the protrusion. The heat exchanger of claim 1 .

11. The identification portions are through holes arranged in a stacking direction of the plurality of plate-like members. The through holes become smaller in the stacking direction. The heat exchanger of claim 1 .

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