Heat exchanger and air conditioning device

Abstract

The heat exchanger includes a plurality of heat transfer tubes and a piping that penetrates the plurality of heat transfer tubes and through which a refrigerant flows, each of the plurality of heat transfer tubes has a plurality of first through holes and a pair of second through holes that are formed inward from both ends and communicate the internal space of each of the plurality of heat transfer tubes with the outside, the plurality of heat transfer tubes include a plurality of header sections formed by connecting the plurality of first through holes of adjacent heat transfer tubes among the plurality of heat transfer tubes, the header sections being smaller than the width of the plurality of heat transfer tubes and communicating the refrigerant between each of the internal spaces of the plurality of heat transfer tubes and serving as inlets and outlets for the refrigerant of the heat transfer tube group formed by the plurality of heat transfer tubes, and the piping is inserted into the pair of second through holes.

Description

[Technical field]

[0001] The present disclosure relates to a heat exchanger and an air conditioner including the heat exchanger. [Background technology]

[0002] Conventionally, fin-tube type heat exchangers, in which heat transfer tubes are inserted through fins, have been used as heat exchangers. Fin-tube type heat exchangers have been designed to improve heat exchange efficiency and reduce size by reducing the diameter of the heat transfer tubes, but structural difficulties have also led to limitations. In contrast, plate-fin stacked type heat exchangers can have a smaller cross-sectional area of ​​the heat transfer flow path than fin-tube type heat transfer tubes, improving heat exchange efficiency and reducing size. In addition, for conventional heat exchangers, heat exchangers that have functions such as an internal heat exchanger (HIC) or gas-liquid separation have been proposed in order to improve heat exchange efficiency (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-107775 A Summary of the Invention [Problem to be solved by the invention]

[0004] The heat exchanger of Patent Document 1 has an internal heat exchanger realized by processing the header portion. However, processing the header portion leads to an increase in size of the header portion, and there is a risk that the heat exchanger will be larger than a heat exchanger that does not have a processed header portion.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a heat exchanger and an air conditioner that are compact while improving heat exchange efficiency. [Means for solving the problem]

[0006] A heat exchanger according to the present disclosure includes a plurality of heat transfer tubes that are arranged in a first direction, each extending in a second direction intersecting the first direction, and having both ends in the second direction sealed and through which a refrigerant flows in the second direction, and a pipe that penetrates the plurality of heat transfer tubes in the first direction and through which a refrigerant flows, each of the plurality of heat transfer tubes is formed with a plurality of first through holes that are formed inside the both ends in the second direction and that connect an internal space of each of the plurality of heat transfer tubes to the outside, and a pair of second through holes that are formed opposite each other in the first direction, To teeth, A first header portion and a second header portion which communicate a refrigerant between the internal spaces of the plurality of heat transfer tubes and serve as an inlet and outlet for the refrigerant of the heat transfer tube group constituted by the plurality of heat transfer tubes, Among the plurality of heat transfer tubes, a plurality of first through holes of adjacent heat transfer tubes are connected to each other. The first header section and the second header section each include In a third direction perpendicular to the first direction and the second direction, the width of the heat transfer tube is smaller than the width of the heat transfer tube. 、 The pipes are inserted into the pair of second through holes. The refrigerant passes through the internal space of the heat transfer tubes between the first header portion and the second header portion. It is something.

[0007] In addition, the air conditioning apparatus according to the present disclosure is composed of a compressor and the above-mentioned heat exchanger, and is equipped with an outdoor heat exchanger that exchanges heat between the outside air and the refrigerant flowing therein, an expansion valve that reduces the pressure of the refrigerant flowing therein, and an indoor heat exchanger that exchanges heat between the indoor air and the refrigerant flowing therein. Effect of the Invention

[0008] In the heat exchanger and air conditioning apparatus according to the present disclosure, a configuration having the function of an internal heat exchanger can be provided within the configuration range of the heat transfer tube group by using a heat transfer tube having a plurality of header portions formed by connecting the first through holes and a pipe disposed in the second through hole of the heat transfer tube. That is, the heat exchanger does not need to provide a configuration having the function of an internal heat exchanger outside the heat transfer tube, and by incorporating the function of an internal heat exchanger, it is also not necessary to provide a header portion larger than a header portion that does not have this function. Therefore, the heat exchanger can be made smaller than a heat exchanger having this function outside the heat transfer tube group while improving heat exchange efficiency by using the heat transfer tube and the pipe having the header portion to function as an internal heat exchanger. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a schematic configuration of a heat exchanger according to a first embodiment. [Diagram 2] 1 is a vertical cross-sectional view of a heat exchanger according to a first embodiment. [Diagram 3] 2 is a view of a heat transfer tube of the heat exchanger according to the first embodiment viewed in a first direction. [Figure 4] 4 is a conceptual diagram of a cross section of the heat transfer tube of FIG. 3 taken along line AA in the heat exchanger according to the first embodiment, viewed in the direction of the arrows. [Diagram 5] FIG. 4 is a vertical sectional view of a modified example of the heat exchanger according to the first embodiment. [Figure 6] 6 is a view of a heat transfer tube of a modified example in the heat exchanger according to the first embodiment, viewed in a first direction. FIG. [Figure 7] FIG. 1 is a refrigerant circuit diagram during cooling operation of an air conditioner equipped with a heat exchanger according to embodiment 1. [Figure 8] FIG. 1 is a refrigerant circuit diagram during defrost operation of an air conditioner equipped with a heat exchanger according to embodiment 1. [Figure 9] 4 is another refrigerant circuit diagram during defrost operation of the air conditioner equipped with the heat exchanger according to the first embodiment. FIG. [Figure 10]FIG. 1 is a refrigerant circuit diagram during heating operation of an air conditioner equipped with a heat exchanger according to embodiment 1. [Figure 11] FIG. 11 is a perspective view showing a schematic configuration of a heat exchanger according to a second embodiment. [Figure 12] FIG. 11 is a vertical sectional view of a modified example of the heat exchanger according to the second embodiment. [Figure 13] FIG. 11 is a refrigerant circuit diagram during heating operation of an air conditioner equipped with a heat exchanger according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a heat exchanger according to the first embodiment and an air conditioner including this heat exchanger will be described with reference to the drawings. In the following drawings including FIG. 1, the relative dimensional relationship and shape of each component may differ from the actual one. In addition, in the following drawings, the same reference numerals are attached to the same or equivalent parts, and this is common throughout the entire specification. In addition, to facilitate understanding, terms indicating directions (e.g., "upper", "lower", "right", "left", "front", "rear", etc.) are used as appropriate, but these notations are only described in this way for the convenience of explanation and do not limit the arrangement and orientation of the device or parts. In the specification, the positional relationship between each component, the extension direction of each component, and the arrangement direction of each component are, in principle, those when the heat exchanger is installed in a usable state.

[0011] Embodiment 1 [Configuration of heat exchanger 100] Fig. 1 is a perspective view showing a schematic configuration of a heat exchanger 100 according to the first embodiment. The white arrows shown in Fig. 1 indicate an example of a refrigerant flow direction. The configuration of the heat exchanger 100 will be described with reference to Fig. 1. Note that the refrigerant flow direction shown by the white arrows below is an example, and the refrigerant flow direction may be opposite to that shown in the figure depending on the case where the heat exchanger 100 functions as an evaporator or a condenser.

[0012] The heat exchanger 100 is a device that exchanges heat between a refrigerant flowing inside the heat exchanger 100 and a fluid flowing outside the heat exchanger 100. In the case of an air-conditioning device, the heat exchanger 100 exchanges heat between the refrigerant flowing inside the heat exchanger 100 and the air flowing outside the heat exchanger 100. The heat exchanger 100 is connected to other heat exchangers and compressors, etc., by refrigerant piping, and constitutes a part of various devices that make up a refrigerant circuit.

[0013] FIG. 2 is a vertical cross-sectional view of the heat exchanger 100 according to the first embodiment. FIG. 3 is a view of the heat transfer tube 10 of the heat exchanger 100 according to the first embodiment in the first direction D1. FIG. 4 is a conceptual diagram of the heat exchanger 100 according to the first embodiment, in which the cross section of the heat transfer tube 10 in FIG. 3 at the position of line AA is viewed in the direction of the arrow. The cross-sectional view shown in FIG. 2 shows the cross section of the heat exchanger 100 in a plane along the first direction D1 and the second direction D2. FIG. 2 also shows a part of the heat exchanger 100. In addition, in FIGS. 2 and 3, a part of the second direction D2 is omitted from the illustration. Hereinafter, the structure of the heat exchanger 100 will be described in detail with reference to FIGS. 1 to 4. In FIGS. 1 and 2, the direction of the refrigerant flow when the heat exchanger 100 is used as an outdoor heat exchanger described later is indicated by a solid white arrow.

[0014] The heat exchanger 100 includes a plurality of heat transfer tubes 10 that are arranged in a first direction D1, each extending in a second direction D2 intersecting the first direction D1, both ends of which are sealed in the second direction D2, and through which a refrigerant flows in the second direction D2. The heat exchanger 100 also includes a pipe 70 that penetrates the plurality of heat transfer tubes 10 in the first direction D1, and through which a refrigerant flows.

[0015] (Heat transfer tube 10) 1, the heat exchanger 100 has a plurality of heat transfer tubes 10 arranged in a first direction D1 and connected to each other. As an example, the heat transfer tubes 10 are flat tubes that extend in a direction in which a tube axis Ax extends (hereinafter also referred to as a tube axis direction) and have a flat shape that is long in one direction in a cross section perpendicular to the tube axis Ax. Note that the heat transfer tubes 10 are preferably, but are not limited to, flat tubes.

[0016] In the following description, the first direction D1 in which the heat transfer tubes 10 are arranged may be referred to as the arrangement direction, the axial direction of the heat transfer tubes 10 may be referred to as the second direction D2 or the longitudinal direction of the heat transfer tubes 10, and the longitudinal direction of the cross section of the heat transfer tube 10 may be referred to as the third direction D3 or the short-side direction of the heat transfer tube 10. The third direction D3 is a direction perpendicular to the first direction D1 and the second direction D2.

[0017] 1, the heat exchanger 100 is defined as being installed such that the arrangement direction (first direction D1) of the heat transfer tubes 10 is the left-right direction. Each heat transfer tube 10 is defined as being disposed such that its tube axis Ax is the up-down direction perpendicular to the arrangement direction (first direction D1) and its short side direction (third direction D3) is the front-rear direction perpendicular to the tube axis direction and the arrangement direction.

[0018] The arrangement of the heat exchanger 100, or the angle between the arrangement direction (first direction D1) of the heat transfer tubes 10 in the heat exchanger 100 and the tube axis direction (second direction D2) of each heat transfer tube 10, is not limited to the above. For example, the heat exchanger 100 may be arranged at an angle such that the tube axis direction of each heat transfer tube 10 is inclined with respect to the up-down direction. Alternatively, when the heat exchanger 100 is installed such that the arrangement direction (first direction D1) of the heat transfer tubes 10 is the left-right direction, the heat exchanger 100 may be configured such that the tube axis direction of each heat transfer tube 10 is inclined with respect to the up-down direction.

[0019] Gaps that are air flow paths P2 are formed between the tube walls 11 of the heat transfer tubes 10 adjacent to each other in the arrangement direction of the heat transfer tubes 10 (first direction D1), and air flows through each gap in the heat exchanger 100 along the short side direction of the heat transfer tubes 10 (third direction D3). The fluid that flows through the heat transfer tubes 10 is a refrigerant. A heat transfer flow path P1a through which the refrigerant flows is provided inside the heat transfer tube 10. Note that the fluid that flows through the heat transfer tube 10 may be other fluids such as water or brine instead of a refrigerant.

[0020] Both ends of the heat transfer tube 10 in the longitudinal direction (second direction D2) are sealed. Specifically, the heat exchanger 100 includes tube sealing portions 20 that close each open end 10e of the heat transfer tube 10 on both sides in the longitudinal direction (second direction D2). In the example of Fig. 2, the tube sealing portions 20 are provided for each heat transfer tube 10 at two locations, one on the upper side and one on the lower side of the flat tube. The tube sealing portions 20 are joined to the open end 10e of the heat transfer tube 10 by joining means such as brazing or an adhesive, for example.

[0021] 2 to 4, each of the heat transfer tubes 10 has a tube wall 11 provided with a heat transfer flow path P1a through which a fluid flows in an internal space. The heat transfer tube 10 has a tube structure in which an internal space through which a refrigerant flows is maintained across the longitudinal direction (second direction D2) of the heat transfer tube 10, i.e., from the upper end to the lower end of the tube wall 11.

[0022] The tube wall 11 of the heat transfer tube 10 has substantially flat tube side wall portions 10a and 10b facing each other in the first direction D1. The tube wall 11 of the heat transfer tube 10 also has curved connecting wall portions 10c and 10d that connect the tube side wall portions 10a and 10b at both ends of the tube side wall portions 10a and 10b in the third direction D3. In the following description, the tube side wall portions 10a and 10b may be referred to as the tube side wall portions 10a, etc.

[0023] Each of the tube side wall portions 10a and 10b has a rectangular shape with a long side extending in the longitudinal direction (second direction D2) of the heat transfer tube 10 and a short side extending in the lateral direction (third direction D3) of the heat transfer tube 10. The tube side wall portions 10a and 10b are flat, but the "flat" in the present application does not have to be a completely flat surface, and may have a structure that appears to be flat as a whole. For example, the tube side wall portions 10a and 10b may have a depression, protrusion, or wave shape formed in a part of the flat area. In FIG. 2, the wall portion on the left side of the tube wall 11 is the tube side wall portion 10a, and the wall portion on the right side of the tube wall 11 is the tube side wall portion 10b. When the heat transfer tube 10 is a circular tube, the tube wall 11 is formed in a cylindrical shape.

[0024] 2 and 3, each of the heat transfer tubes 10 is formed with a plurality of first through holes 30 that are formed inward from both ends in the second direction D2 and communicate the internal space of each of the heat transfer tubes 10 with the outside. Also, each of the heat transfer tubes 10 is formed with a pair of second through holes 40 that are formed to face each other in the first direction D1.

[0025] 2 and 3, the tube side wall portion 10a and the tube side wall portion 10b are formed with a first through hole 30. The left tube side wall portion 10a is formed with a first through hole 30a and a first through hole 30c penetrating in the first direction D1, and the right tube side wall portion 10b is formed with a first through hole 30b and a first through hole 30d penetrating in the first direction D1.

[0026] The first through hole 30a and the first through hole 30b are through holes constituting the first header portion 51 described later. The first through hole 30a and the first through hole 30b are formed at positions facing each other in the first direction D1. The first through hole 30c and the first through hole 30d are through holes constituting the second header portion 52 described later. The first through hole 30c and the first through hole 30d are formed at positions facing each other in the first direction D1. The first through hole 30 is a general term for the first through hole 30a, the first through hole 30b, the first through hole 30c, and the first through hole 30d. The first through hole 30 is a through hole constituting the header portion 50 described later, the first through hole 30a, the first through hole 30b, the first through hole 30c, and the first through hole 30d.

[0027] 2 and 3, the pipe side wall portion 10a and the pipe side wall portion 10b are formed with a second through hole 40 penetrating in the first direction D1. A pipe 70 is inserted into the second through hole 40.

[0028] 2, adjacent heat transfer tubes 10 have connecting portions 12 for connecting their tube walls 11. Adjacent heat transfer tubes 10 have connecting portions 12 that connect the tube walls 11 and communicate the heat transfer flow paths P1a inside the tube walls 11. Each heat transfer tube 10 has a tube wall 11, and connecting protrusions 12a and 12b that configure the connecting portion 12 and extend from the tube wall 11 in a first direction D1 outward. Each heat transfer tube 10 also has a tube wall 11, and connecting protrusions 12c and 12d that configure the connecting portion 12 and extend from the tube wall 11 in the first direction D1 outward.

[0029] The connecting portion 12 of adjacent heat transfer tubes 10 has a cylindrical shape with a hollow portion Sg that penetrates in the first direction D1. The connecting portion 12 is formed by combining a connecting protrusion 12a and a connecting protrusion 12b. The connecting portion 12 is also formed by combining a connecting protrusion 12c and a connecting protrusion 12d. In the example of FIG. 2, the connecting portion 12 is formed by inserting the connecting protrusion 12b into the connecting protrusion 12a. The connecting protrusion 12a and the connecting protrusion 12b that constitute the connecting portion 12 are configured to fit together, for example.

[0030] The connecting portion 12 is formed by inserting the connecting protrusion 12d into the connecting protrusion 12c. The connecting protrusion 12c and the connecting protrusion 12d constituting the connecting portion 12 are configured to, for example, fit together. In the following description, the connecting protrusion 12a, the connecting protrusion 12b, the connecting protrusion 12c, and the connecting protrusion 12d may be referred to as the connecting protrusion 12a, etc. The connecting portion 12 is configured by the connecting protrusion 12a, etc. formed on at least one of the opposing tube side wall portions 10a, etc. of the adjacent heat transfer tubes 10 and protruding from the periphery of the first through hole 30 in the first direction D1.

[0031] In addition, the connecting portion 12 does not have to be configured such that the connecting protrusions 12a and 12b fit together. For example, the connecting portion 12 may be configured such that the connecting protrusions 12a and 12b are joined together by a joining means such as brazing or an adhesive. The connecting protrusions 12c and 12d may also be joined together by the above-mentioned joining means.

[0032] The connecting portion 12 is composed of a connecting protrusion 12a or a connecting protrusion 12b provided on at least one of the opposing tube side wall portions 10a and 10b of the adjacent heat transfer tubes 10. The connecting protrusion 12a extends from the periphery of the first through hole 30a toward the opposing tube side wall portion 10b. The connecting protrusion 12b extends from the periphery of the first through hole 30b toward the opposing tube side wall portion 10a.

[0033] The connecting portion 12 is composed of a connecting protrusion 12c or a connecting protrusion 12d provided on at least one of the opposing tube side wall portions 10a and 10b of the adjacent heat transfer tubes 10. The connecting protrusion 12c extends from the periphery of the first through hole 30c toward the opposing tube side wall portion 10b. The connecting protrusion 12d extends from the periphery of the first through hole 30d toward the opposing tube side wall portion 10a.

[0034] In FIG. 2, the connecting portion 12 is a cylindrical member formed on both of the tube side wall portions 10a and 10b of the adjacent heat transfer tubes 10. Concatenation The connecting portion 12 is composed of a protrusion 12a and a connecting protrusion 12b. The connecting portion 12 is also composed of a cylindrical connecting protrusion 12c and a connecting protrusion 12d formed on both of the opposing tube side wall portions 10a and 10b of the adjacent heat transfer tubes 10.

[0035] The first through holes 30a and 30b and the connecting protrusions 12a and 12b can be formed, for example, by burring, which is a process in which holes are drilled in the flat plate portion of the heat transfer tube 10 and the flat plate portion at the periphery is deformed so as to rise into a cylindrical shape. The first through holes 30c and 30d and the connecting protrusions 12c and 12d can also be formed by burring or the like.

[0036] 2, the connecting portion 12 connects the first through hole 30a and the first through hole 30b provided in the tube side wall portion 10a and the tube side wall portion 10b by the hollow portion Sg, thereby communicating the internal spaces of the adjacent tube walls 11. Similarly, the connecting portion 12 connects the first through hole 30c and the first through hole 30d provided in the tube side wall portion 10a and the tube side wall portion 10b by the hollow portion Sg, thereby communicating the internal spaces of the adjacent tube walls 11. In addition, the connecting portion 12 has a function of separating the hollow portion Sg on the inside from the air flow path P2, which is the space outside the connecting portion 12.

[0037] 2 and 3, the first through holes 30 and the connecting portions 12 are formed on the inside of the open ends 10e on both sides in the longitudinal direction (second direction D2) of the heat transfer tubes 10. Specifically, in the heat exchanger 100 arranged as shown in FIG. Concatenation The protrusion 12a and the connecting protrusion 12b are formed below the upper open end 10e of the heat transfer tube 10 and above the lower open end 10e of the heat transfer tube 10.

[0038] Such a heat transfer tube 10 can be manufactured, for example, by forming the first through hole 30 and the connecting protrusions 12a and 12b in advance in a member that is to become the heat transfer tube 10, and then shaping the member by roll forming. Also, the connecting protrusions 12a and 12b may be formed by raising the periphery of the hole when forming the first through hole 30 in the member that is to become the heat transfer tube 10. For the heat transfer tube 10, a metal material having high thermal conductivity, such as aluminum, copper, or brass, is used.

[0039] The refrigerant flow path in the heat exchanger 100 is provided in the tube wall 11 of each heat transfer tube 10 and has a heat transfer flow path P1a extending in the longitudinal direction (second direction D2) of the heat transfer tube 10. The refrigerant flow path in the heat exchanger 100 also has a header flow path P1b extending in the arrangement direction (first direction D1) of the multiple heat transfer tubes 10 and connecting the heat transfer flow paths P1a of the multiple heat transfer tubes 10. The refrigerant flow path in the heat exchanger 100 also has a header flow path P1c extending in the arrangement direction (first direction D1) of the multiple heat transfer tubes 10 and connecting the heat transfer flow paths P1a of the multiple heat transfer tubes 10.

[0040] The heat transfer flow path P1a communicates with the header flow path P1b at one end of the heat transfer flow path P1a in the longitudinal direction (second direction D2) of the heat transfer tube 10, and communicates with the header flow path P1c at the other end of the heat transfer flow path P1a. The header flow path P1b and the header flow path P1c each communicate with a plurality of heat transfer flow paths P1a. The refrigerant flow path of the heat exchanger 100 is composed of the plurality of heat transfer flow paths P1a, the header flow path P1b provided in the upper part of the heat exchanger 100, and the header flow path P1c provided in the lower part of the heat exchanger 100.

[0041] The above-mentioned first through hole 30a, the first through hole 30b, the hollow portion Sg of the connecting portion 12, etc., constitute a header flow path P1b, and a refrigerant flows through the hollow portion Sg. The first through hole 30c, the first through hole 30d, the hollow portion Sg of the connecting portion 12, etc., constitute a header flow path P1c, and a refrigerant flows through the hollow portion Sg.

[0042] In the heat exchanger 100, the connecting portion 12 is formed of a part of the heat transfer tube 10, and the portion of the header flow passages P1b and P1c that is arranged between the tube walls 11 of the heat transfer tubes 10 is a hollow portion Sg inside the connecting portion 12. Therefore, in the heat exchanger 100, the header flow passages P1b and P1c are formed in the heat transfer tubes 10 that are heat exchange members, so that there is no need to provide a header portion on the outside of the multiple heat transfer tubes 10.

[0043] The heat transfer tubes 10 have a plurality of header sections 50 formed by connecting the first through holes 30 of the adjacent heat transfer tubes 10 among the plurality of heat transfer tubes 10. The header section 50 is formed to extend in a horizontal direction, for example. The header section 50 is formed to be smaller than the width of the plurality of heat transfer tubes 10 in a third direction D3 perpendicular to the first direction D1 and the second direction D2. The header section 50 communicates the refrigerant with the internal spaces of the plurality of heat transfer tubes 10 as shown in FIG. 1, and serves as an inlet / outlet 51a and an inlet / outlet 52a for the refrigerant of the heat transfer tube group 15 formed by the plurality of heat transfer tubes 10. The end of the header section 50 opposite to the inlet / outlet 51a and the inlet / outlet 52a is closed by the tube wall 11 or the like.

[0044] The header section 50 functions as a distribution mechanism that distributes the refrigerant flowing into the heat transfer tube group 15 to the multiple heat transfer tubes 10. In addition, the header section 50 functions as a joining mechanism when the refrigerant flowing out from the multiple heat transfer tubes 10 joins when the refrigerant flows out from the heat transfer tube group 15.

[0045] The header section 50 includes at least a first header section 51 and a second header section 52. The header section 50 is a general term for the first header section 51 and the second header section 52. As shown in Fig. 1 and Fig. 2, the multiple header sections 50 have the first header section 51 provided at one end side of the heat transfer tube 10 in the second direction D2, and the second header section 52 provided at the other end side of the heat transfer tube 10. The header section 50 is provided on the inside of the end of the heat transfer tube 10 in the second direction D2.

[0046] As described above, the multiple heat transfer tubes 10 have multiple connecting portions 12 that directly connect the multiple first through holes 30 of adjacent heat transfer tubes 10 among the multiple heat transfer tubes 10, and each of the multiple header portions 50 is composed of multiple connecting portions 12. In the heat exchanger 100, the first through holes 30 are directly connected to each other by the connecting portions 12 provided in the first through holes 30.

[0047] The internal heat exchanger (HIC) portion of the heat exchanger 100 may be a part or the whole of the heat transfer tube group 15. When the internal heat exchanger (HIC) portion of the heat exchanger 100 is a part of the heat transfer tube group 15, for example, the heat exchanger 100 has a part of the connection portion 12 closed by a partition plate (not shown) or the like.

[0048] (Pipe 70) As described above, the piping 70 penetrates the multiple heat transfer tubes 10 in the first direction D1, and a refrigerant flows inside the piping 70. The flow of the refrigerant flowing through the piping 70 may be a counter flow or a parallel flow to the flow direction of the refrigerant flowing through the header portion 50. A refrigerant of a system separate from the refrigerant flowing through the header portion 50 flows through the piping 70.

[0049] The pipes 70 are inserted into a pair of second through holes 40 in each heat transfer tube 10. That is, the pipes 70 are inserted into a plurality of second through holes 40 in the heat transfer tube group 15.

[0050] The piping 70 is arranged so as to be closer to one of the header portions 50, either the first header portion 51 or the second header portion 52. For example, the piping 70 is arranged closer to one of the header portions 50 than the center between the first header portion 51 and the second header portion 52 in the second direction D2. The piping 70 is preferably arranged close to the header portion 50 on the side into which the refrigerant flows in when the air conditioning device 200 described below is in cooling operation. The piping 70 is arranged, for example, between the first header portion 51 and the second header portion 52 in the second direction D2.

[0051] The pipe diameter of the pipe 70 is smaller than the inner diameter of the heat transfer tube 10 in the third direction D3. The pipe diameter of the pipe 70 is smaller than the pipe diameter of the header section 50. The pipe 70 is a circular pipe having a cylindrical cross-sectional shape. Note that the pipe 70 is not limited to a circular pipe, and may be a pipe having a cross-sectional shape other than a cylinder.

[0052] The heat exchanger 100 has one pipe 70 for either the first header portion 51 or the second header portion 52. The number of pipes 70 is not limited to one, and a plurality of pipes may be used.

[0053] In the first embodiment, the refrigerant flowing through the pipe 70 is different from the refrigerant flowing into the header portion 50. In the first embodiment, the pipe 70 does not have a through hole communicating with the internal space of each heat transfer tube 10. Therefore, the pipe 70 does not communicate with the internal spaces of each of the heat transfer tubes 10. The heat exchanger 100 exchanges heat between the refrigerant flowing inside the pipe 70 and the refrigerant flowing inside the heat transfer tubes 10. Refrigerant flows in and out of the pipe 70 from a circuit outside the heat exchanger 100, and exchanges heat with the refrigerant in the heat transfer tube 10.

[0054] [Modifications of the heat exchanger 100] Fig. 5 is a vertical cross-sectional view of a modified example of the heat exchanger 100 according to the first embodiment. Fig. 6 is a view of a modified heat transfer tube 10 in the heat exchanger 100 according to the first embodiment, as viewed in the first direction D1. Note that part of the second direction D2 is not illustrated in Figs. 5 and 6. Fig. 5 also shows a part of the heat exchanger 100. A modified example of the heat exchanger 100 will be described with reference to Figs. 5 and 6.

[0055] The heat exchanger 100 may have a header pipe 80 in the header section 50 without using the connecting portions 12. That is, the heat exchanger 100 may use the header pipe 80 instead of the connecting portions 12 to connect the first through holes 30 together. The heat exchanger 100 may connect the first through holes 30 together using the header pipe 80 as a member separate from the heat transfer tubes 10.

[0056] The multiple heat transfer tubes 10 are inserted into the multiple first through holes 30, and have multiple header tubes 80 that connect the multiple first through holes 30 of adjacent heat transfer tubes 10 among the multiple heat transfer tubes 10. Each of the multiple header sections 50 is formed with the header tube 80 inserted into the first through hole 30. The header tube 80 has multiple holes 82 formed therein that communicate with the internal spaces of each of the multiple heat transfer tubes 10.

[0057] Each of the heat transfer tubes 10 has a tube wall 11 provided with a heat transfer flow path P1a through which a fluid flows in an internal space. The tube wall 11 has tube side wall portions 10a etc. facing each other in a first direction D1, and the tube side wall portions 10a etc. have first through holes 30 formed therein into which header tubes 80 are inserted. In the heat exchanger 100, the header tubes 80 indirectly connect the first through holes 30 to each other.

[0058] As described above, the header pipe 80 penetrates the multiple heat transfer pipes 10 in the first direction D1, and the refrigerant flows inside. The piping diameter of the header pipe 80 is larger than the piping diameter of the pipe 70. The header pipe 80 is, for example, a circular pipe having a cylindrical cross-sectional shape. Note that the header pipe 80 is not limited to a circular pipe, and may be a pipe having a cross-sectional shape other than a cylinder.

[0059] A header flow path P1b or a header flow path P1c is formed inside the header pipe 80 or the connecting portion 12. For example, the header pipe 80 or the connecting portion 12 constituting the first header portion 51 constitutes the header flow path P1b, and the header pipe 80 or the connecting portion 12 constituting the second header portion 52 constitutes the header flow path P1c.

[0060] Next, an example of the operation of the heat exchanger 100 will be described with reference to Figures 1 and 2. As shown by the outline arrow in Figure 1, a high-temperature, high-pressure gaseous refrigerant flows into the heat exchanger 100 from the refrigerant inlet / outlet 51a of the first header section 51. As shown in Figure 2, in the heat exchanger 100, the high-temperature, high-pressure gaseous refrigerant first flows into the header flow path P1b of the first header section 51 that penetrates the upper part of the multiple heat transfer tubes 10 in the left-right direction, and flows through the header flow path P1b. In the process, the high-temperature, high-pressure gaseous refrigerant is distributed and flows into the heat transfer flow paths P1a provided in the respective tube walls 11 of the multiple heat transfer tubes 10.

[0061] The high-temperature, high-pressure gaseous refrigerant that has flowed into each heat transfer flow path P1a flows downward in the internal space of the tube wall 11. At this time, the high-temperature, high-pressure gaseous refrigerant exchanges heat with the air flowing through the gaps between the tube walls 11 of the heat transfer tubes 10 (i.e., the air flow path P2) through the tube walls 11, and condenses, becoming a high-pressure two-phase gas-liquid refrigerant. The high-pressure two-phase gas-liquid refrigerant flows from the multiple heat transfer flow paths P1a into the header flow paths P1c of the second header section 52 that penetrates the lower parts of the multiple heat transfer tubes 10, and merges in the header flow path P1c. The high-pressure two-phase gas-liquid refrigerant that has merged in the header flow path P1c flows through the header flow path P1c, and flows out of the heat exchanger 100 from the refrigerant inlet / outlet 52a (see FIG. 1) of the second header section 52.

[0062] The heat exchanger 100 shown in Figures 1 to 6 is an example of the heat exchanger 100 of the present disclosure, and the number, shape, arrangement, etc. of the heat transfer tubes 10, the piping 70, the heat transfer flow paths P1a, the header flow paths P1b and the header flow paths P1c can be changed as appropriate.

[0063] [Air conditioner 200] Fig. 7 is a refrigerant circuit diagram of the air conditioner 200 equipped with the heat exchanger 100 according to embodiment 1 during cooling operation. Fig. 8 is a refrigerant circuit diagram of the air conditioner 200 equipped with the heat exchanger 100 according to embodiment 1 during defrost operation. Fig. 9 is another refrigerant circuit diagram of the air conditioner 200 equipped with the heat exchanger 100 according to embodiment 1 during defrost operation. Fig. 10 is a refrigerant circuit diagram of the air conditioner 200 equipped with the heat exchanger 100 according to embodiment 1 during heating operation. As shown in Figs. 7 to 10, the heat exchanger 100 constitutes a part of the refrigerant circuit 250 through which the refrigerant circulates in the air conditioner 200.

[0064] The air conditioner 200 is composed of a compressor 201, a flow path switching device 202 that switches the flow path of the refrigerant, and a heat exchanger 100, and has an outdoor heat exchanger 203 that exchanges heat between the outdoor air and the refrigerant flowing inside. The air conditioner 200 also has an expansion valve 204 that reduces the pressure of the refrigerant flowing inside, and an indoor heat exchanger 205 that exchanges heat between the indoor air and the refrigerant flowing inside. The air conditioner 200 does not need to have the flow path switching device 202. In this case, the refrigerant circuit 250 of the air conditioner 200 is configured in the portion of the flow path switching device 202 as in the circuit configuration of the flow path switching device 202 shown in each figure.

[0065] 7 to 10, in an air conditioner 200, a compressor 201, a flow path switching device 202, an outdoor heat exchanger 203, and an expansion valve 204 are provided in an outdoor unit 231, and an indoor heat exchanger 205 is provided in an indoor unit 232. A header section 50 (see FIG. 2), which serves as an inlet and outlet for the refrigerant of the heat exchanger 100, is connected to the flow path switching device 202 and the expansion valve 204 of a refrigerant circuit 250.

[0066] In the air conditioner 200, a compressor 201, a flow path switching device 202, an outdoor heat exchanger 203, an expansion valve 204, and an indoor heat exchanger 205 are connected by refrigerant piping 255 to constitute a refrigerant circuit 250 through which the refrigerant circulates. The air conditioner 200 shown in Figs. 7 to 10 is capable of both cooling operation and heating operation by switching the flow path switching device 202.

[0067] The compressor 201 draws in a low-temperature, low-pressure refrigerant, compresses the drawn refrigerant, and discharges a high-temperature, high-pressure refrigerant. The flow path switching device 202 is, for example, a four-way valve, and switches between cooling operation and heating operation by switching the direction in which the refrigerant flows. The flow path switching device 202 connects the discharge side of the compressor 201 to the indoor heat exchanger 205 during heating operation, and connects the discharge side of the compressor 201 to the outdoor heat exchanger 203 during cooling operation.

[0068] The outdoor heat exchanger 203 is composed of a heat exchanger 100. The outdoor heat exchanger 203 exchanges heat between the outdoor air and the refrigerant flowing inside the outdoor heat exchanger 203. As shown in FIG. 7, the outdoor heat exchanger 203 functions as a condenser 221 that radiates heat of the refrigerant to the outdoor air and condenses the refrigerant during cooling operation. As shown in FIG. 10, the outdoor heat exchanger 203 functions as an evaporator 222 that evaporates the refrigerant and cools the outdoor air with the heat of evaporation during heating operation. As shown in FIGS. 7 to 10, a gas-liquid two-phase refrigerant flows in the outdoor heat exchanger 203.

[0069] The expansion valve 204 is, for example, an electronic expansion valve capable of adjusting the throttle opening, and by adjusting the opening, the pressure of the refrigerant flowing into the outdoor heat exchanger 203 or the indoor heat exchanger 205 is controlled. Note that, in the embodiment, the expansion valve 204 is provided in the outdoor unit 231, but it may be provided in the indoor unit 232, and the installation location is not limited.

[0070] The indoor heat exchanger 205 exchanges heat between the indoor air and the refrigerant flowing inside the indoor heat exchanger 205. As shown in Fig. 7, the indoor heat exchanger 205 functions as an evaporator 222 that evaporates the refrigerant and cools the outdoor air with the heat of vaporization during cooling operation. Also, as shown in Fig. 10, the indoor heat exchanger 205 functions as a condenser 221 that dissipates heat of the refrigerant to the outdoor air and condenses the refrigerant during heating operation.

[0071] The air conditioning device 200 may have an outdoor fan 203a and an indoor fan 205a for blowing air to the outdoor heat exchanger 203 and the indoor heat exchanger 205. The outdoor fan 203a and the indoor fan 205a form a flow of air that flows through a flow path P2 (see FIG. 2) between adjacent heat transfer tubes 10.

[0072] 7 to 10, the refrigerant circuit 250 includes a main circuit 251 and a branch circuit 252. The main circuit 251 is a circuit in which the compressor 201, the flow switching device 202, the outdoor heat exchanger 203, the expansion valve 204, and the indoor heat exchanger 205 are connected via refrigerant piping 255, and in which the refrigerant circulates. The branch circuit 252 is connected to the piping 70 of the outdoor heat exchanger 203, and is a circuit constituted by the refrigerant piping 255 in which the refrigerant that branches off from the main circuit 251 and merges with the main circuit 251 via the piping 70 flows.

[0073] 7 has one end connected to a main circuit 251 between the expansion valve 204 and the outdoor heat exchanger 203, and the other end connected to the main circuit 251 on the suction side of the compressor 201 via a pipe 70. The main circuit 251 on the suction side of the compressor 201 is the main circuit 251 in the portion between the compressor 201 and the flow path switching device 202 during cooling operation, in other words, the main circuit 251 in the portion between the compressor 201 and the indoor heat exchanger 205 during cooling operation.

[0074] The branch circuit 252 is provided with a check valve 206, a fixed fluid resistance 207, and a pipe 70. The check valve 206, the fixed fluid resistance 207, and the pipe 70 are provided in this order in the flow direction of the refrigerant flowing through the branch circuit 252 during cooling operation. In the flow direction of the refrigerant flowing through the branch circuit 252 during cooling operation, the check valve 206 and the fixed fluid resistance 207 are provided on the upstream side of the pipe 70. During cooling operation, the heat exchanger 100 extracts a part of the high-temperature, high-pressure refrigerant by the fixed fluid resistance 207 and reduces the pressure of the refrigerant, and a low-pressure gas-liquid two-phase refrigerant flows through the branch circuit 252.

[0075] The branch circuit 252 of the air conditioner 200 shown in Fig. 8 has one end connected to the main circuit 251 on the discharge side of the compressor 201, and the other end connected to the main circuit 251 on the suction side of the compressor 201 via the piping 70. The main circuit 251 on the discharge side of the compressor 201 is the main circuit 251 in the portion between the compressor 201 and the flow path switching device 202 during the defrost operation, in other words, the main circuit 251 in the portion between the compressor 201 and the outdoor heat exchanger 203 during the defrost operation. The main circuit 251 on the suction side of the compressor 201 is the main circuit 251 in the portion between the flow path switching device 202 and the compressor 201 during the defrost operation, in other words, the main circuit 251 in the portion between the indoor heat exchanger 205 and the compressor 201 during the defrost operation.

[0076] The branch circuit 252 is provided with a bypass valve 208 and a pipe 70. The bypass valve 208 and the pipe 70 are provided in this order in the flow direction of the refrigerant flowing through the branch circuit 252 during defrost operation. In the flow direction of the refrigerant flowing through the branch circuit 252 during defrost operation, the bypass valve 208 is provided upstream of the pipe 70. In the heat exchanger 100, during heating operation as shown in FIG. 8, hot gas, which is a part of the refrigerant discharged from the compressor 201, is taken out by the bypass valve 208 and flows through the branch circuit 252, and flows near the outlet of the condenser 221 during defrost operation.

[0077] 9 has one end connected to the main circuit 251 between the flow path switching device 202 and the outdoor heat exchanger 203, and the other end connected to the main circuit 251 between the expansion valve 204 and the outdoor heat exchanger 203 via the piping 70. In other words, the branch circuit 252 of the air conditioner 200 has one end connected to the main circuit 251 between the compressor 201 and the outdoor heat exchanger 203, and the other end connected to the main circuit 251 between the expansion valve 204 and the outdoor heat exchanger 203 via the piping 70.

[0078] The branch circuit 252 is provided with a bypass valve 209 and a pipe 70. The bypass valve 209 and the pipe 70 are provided in this order in the flow direction of the refrigerant flowing through the branch circuit 252 during defrost operation. In the flow direction of the refrigerant flowing through the branch circuit 252 during defrost operation, the bypass valve 209 is provided on the upstream side of the pipe 70. During the defrost operation shown in FIG. 9, the heat exchanger 100 extracts a part of the high-temperature, high-pressure refrigerant flowing out from the upstream of the condenser 221 by the bypass valve 209, flows through the branch circuit 252, and causes the refrigerant to flow into the condenser 221 during the defrost operation, thereby promoting melting of frost.

[0079] 10 has one end connected to the main circuit 251 between the indoor heat exchanger 205 and the expansion valve 204, and the other end connected to the main circuit 251 between the outdoor heat exchanger 203 and the flow path switching device 202 via the piping 70. In other words, the branch circuit 252 of the air conditioner 200 has one end connected to the main circuit 251 between the indoor heat exchanger 205 and the expansion valve 204, and the other end connected to the main circuit 251 between the outdoor heat exchanger 203 and the suction side of the compressor 201 via the piping 70.

[0080] The branch circuit 252 is provided with a bypass valve 209, a pipe 70, and a fixed fluid resistance 210. The bypass valve 209, the pipe 70, and the fixed fluid resistance 210 are provided in this order in the flow direction of the refrigerant flowing through the branch circuit 252 during heating operation. In the flow direction of the refrigerant flowing through the branch circuit 252 during heating operation, the bypass valve 209 is provided on the upstream side of the pipe 70. In the flow direction of the refrigerant flowing through the branch circuit 252 during heating operation, the fixed fluid resistance 210 is provided on the downstream side of the pipe 70. In the heat exchanger 100, during heating operation shown in FIG. 10, a part of the high-temperature and high-pressure refrigerant flowing out from the condenser 221 flows through the branch circuit 252.

[0081] When the heat exchanger 100 functions as the evaporator 222 as shown in FIG. 10, the air conditioner 200 can achieve the following effects. The air conditioner 200 extracts high-temperature, high-pressure refrigerant from the refrigerant circuit 250 between the outlet of the condenser 221 and the expansion valve 204, and causes it to flow into the piping 70 provided near the outlet of the evaporator 222. The air conditioner 200 then reduces the pressure of the refrigerant flowing out of the piping 70 by passing it through the fixed fluid resistance 210, and makes it uniform with the refrigerant to be sucked into the compressor 201. The air conditioner 200 connects a branch circuit 252 having the piping 70 to the piping of the main circuit 251 through which the refrigerant to be sucked into the compressor 201 flows. The air conditioner 200 heat-exchanges the two-phase refrigerant near the outlet of the heat exchanger 100 and gasifies it, thereby increasing the ratio of the two-phase refrigerant in the heat exchanger 100, thereby reducing pressure loss and improving performance.

[0082] In the air conditioner 200, as a result of the compressor 201 operating, a refrigeration cycle is performed in which the refrigerant circulates through the compressor 201, the outdoor heat exchanger 203, the expansion valve 204, and the indoor heat exchanger 205 while undergoing a phase change.

[0083] During cooling operation of the air conditioner 200 shown in FIG. 7, the refrigerant compressed by the compressor 201 is sent to the outdoor heat exchanger 203. In the outdoor heat exchanger 203, the refrigerant releases heat to the outdoor air and is condensed. After that, the refrigerant is sent to the expansion valve 204, where it is decompressed, and then sent to the indoor heat exchanger 205. After that, the refrigerant takes in heat from the indoor air in the indoor heat exchanger 205 and evaporates, and then returns to the compressor 201. Therefore, during cooling operation of the air conditioner 200, the outdoor heat exchanger 203 functions as a condenser 221, and the indoor heat exchanger 205 functions as an evaporator 222. When the refrigerant flows through the main circuit 251 during the defrost operation shown in FIG. 8 and FIG. 9, the refrigerant flows as described in FIG. 7.

[0084] During heating operation of the air conditioner 200, the refrigerant compressed by the compressor 201 is sent to the indoor heat exchanger 205. In the indoor heat exchanger 205, the refrigerant releases heat to the indoor air and is condensed. The refrigerant is then sent to the expansion valve 204, where it is decompressed, and then sent to the outdoor heat exchanger 203. The refrigerant then absorbs heat from the outdoor air in the outdoor heat exchanger 203 and evaporates, before returning to the compressor 201. Therefore, during heating operation of the air conditioner 200, the outdoor heat exchanger 203 functions as an evaporator 222, and the indoor heat exchanger 205 functions as a condenser 221.

[0085] In the air-conditioning apparatus 200 shown in Figures 7 to 10, the heat exchanger 100 is used in the outdoor heat exchanger 203, but the heat exchanger 100 may be used in the indoor heat exchanger 205. In addition, in the air-conditioning apparatus 200 shown in Figures 7 to 10, a form in which the piping 70 is installed near the outlet of the heat exchanger 100 has been described, but the piping 70 can also be installed in the header section 50 in the heat exchanger 100 in a double-pipe structure.

[0086] [Effects of the heat exchanger 100] The heat exchanger 100 includes a plurality of heat transfer tubes 10 arranged in a first direction D1, each extending in a second direction D2 intersecting the first direction D1, with both ends in the second direction D2 sealed and a refrigerant flowing through the inside in the second direction D2. The heat exchanger 100 also includes a pipe 70 penetrating the plurality of heat transfer tubes 10 in the first direction D1 and through which a refrigerant flows. Each of the plurality of heat transfer tubes 10 has a plurality of first through holes 30 formed on the inside of both ends in the second direction D2 and connecting the internal space of each of the plurality of heat transfer tubes 10 to the outside. Each of the plurality of heat transfer tubes 10 also has a pair of second through holes 40 formed to face each other in the first direction D1. The plurality of heat transfer tubes 10 include a plurality of header portions 50 formed by connecting the plurality of first through holes 30 of adjacent heat transfer tubes 10 among the plurality of heat transfer tubes 10. The multiple header portions 50 are formed to be smaller in width than the multiple heat transfer tubes 10 in a third direction D3 perpendicular to the first direction D1 and the second direction D2. The multiple header portions 50 communicate the refrigerant with the internal spaces of the multiple heat transfer tubes 10, and serve as inlets and outlets for the refrigerant of the heat transfer tube group 15 formed by the multiple heat transfer tubes 10. Then, piping 70 is inserted into the pair of second through holes 40.

[0087] The heat exchanger 100 can be provided with a configuration having a function as an internal heat exchanger within the configuration range of the heat transfer tube group 15 by the heat transfer tube 10 having a plurality of header portions 50 formed by connecting the first through holes 30 to each other and the piping 70 arranged in the second through hole 40 of the heat transfer tube 10. That is, the heat exchanger 100 does not need to provide a configuration having a function as an internal heat exchanger outside the heat transfer tube 10, and by incorporating the function as an internal heat exchanger, it is not necessary to provide a header portion larger than a header portion not having the function. Therefore, the heat exchanger 100 can be made smaller than a heat exchanger having the function outside the heat transfer tube group 15 while improving the heat exchange efficiency by performing the function as an internal heat exchanger by the heat transfer tube 10 having the header portion 50 and the piping 70. Therefore, the heat exchanger 100 can be installed in a smaller space than a heat exchanger having the function outside the heat transfer tube group 15.

[0088] In addition, by using the piping 70, the heat exchanger 100 can perform heat exchange between the external refrigerant brought into the heat exchanger 100 from the piping 70 and the refrigerant flowing inside the heat transfer tube 10 with a simple structure.

[0089] In a heat exchanger, when the header portion is made to function as an internal heat exchanger, the manufacturing process of the header portion becomes complicated, which may result in increased costs. Compared to when the header portion is made to function as an internal heat exchanger, the heat exchanger 100 requires only the provision of piping 70, making it easier to manufacture and reducing costs compared to when the header portion is processed to function as an internal heat exchanger. With the above configuration, the heat exchanger 100 can provide a small, high-performance, and cost-effective heat exchanger.

[0090] Further, the multiple header parts 50 have a first header part 51 provided on one end side of the heat transfer tube 10 and a second header part 52 provided on the other end side of the heat transfer tube 10 in the second direction D2. The piping 70 is arranged so as to be closer to either the first header part 51 or the second header part 52. When the heat exchanger 100 is the condenser 221, heat exchange is performed between the refrigerant in a two-phase state inside the condenser 221 and the refrigerant inside the piping 70. When the piping 70 is arranged near the header part 50 on the side where the gas refrigerant flows in during cooling operation, the refrigerant inside the heat transfer tube 10 is heat exchanged by the piping 70 first on the side closer to a gas state than to a liquid state, so that the refrigerant inside the heat transfer tube 10 is likely to be in a two-phase state with high heat exchange efficiency. Therefore, the heat exchanger 100 is likely to exchange heat between the refrigerant inside the heat transfer tube 10 and the air outside the heat transfer tube 10.

[0091] The heat transfer tubes 10 have a plurality of connecting portions 12 that directly connect the first through holes 30 of adjacent heat transfer tubes 10 among the plurality of heat transfer tubes 10. Each of the plurality of header portions 50 is formed of a plurality of connecting portions 12. By having this configuration, the heat exchanger 100 can be made smaller in size than a heat exchanger having a header portion provided outside the heat transfer tubes 10. Therefore, the heat exchanger 100 can require a smaller installation space than a heat exchanger having a header portion outside the heat transfer tube group 15.

[0092] Adjacent heat transfer tubes 10 have connecting portions 12 that connect the tube walls 11 and communicate the heat transfer flow paths P1a inside the tube walls 11. The connecting portions 12 are formed on at least one of the opposing tube side walls 10a of the adjacent heat transfer tubes 10 and are configured with connecting protrusions 12a and 12b that protrude in the first direction D1 from the periphery of the first through hole 30. The connecting portions 12 are also configured with connecting protrusions 12c and 12d that have a similar structure to the connecting protrusion 12a.

[0093] In the heat exchanger 100, the width in the first direction D1 of the air flow path P2 (i.e., the gap between the pipe walls 11) can be changed by changing the length of the connecting portion 12, so that the width in the first direction D1 of the air flow path P2 can be increased without narrowing the width in the first direction D1 of the heat transfer flow path P1a of the fluid. Therefore, the degree of freedom in designing the air flow path P2 in the headerless heat exchanger 100 can be increased.

[0094] The connecting portion 12 is composed of connecting protrusions 12a and 12b, or connecting protrusions 12c and 12d, formed on both the opposing tube side wall portions 10a and 10b of the adjacent heat transfer tubes 10. The connecting protrusions 12a and 12b at least partially overlap in the first direction D1. The connecting protrusions 12c and 12d at least partially overlap in the first direction D1. This allows a part of the connecting portion 12 to have a double-wall structure, thereby increasing the strength of the connecting portion 12.

[0095] Further, the heat transfer tubes 10 are inserted into the first through holes 30 and have a plurality of header tubes 80 that connect the first through holes 30 of the adjacent heat transfer tubes 10. Each of the header sections 50 is formed of the header tube 80 inserted into the first through hole 30, and the header tube 80 has a plurality of holes 82 that communicate with the internal space of each of the heat transfer tubes 10. By having this configuration, the heat exchanger 100 can be made smaller than a heat exchanger having a header section provided outside the heat transfer tube 10. Therefore, the heat exchanger 100 can be installed in a smaller space than a heat exchanger having a header section outside the heat transfer tube group 15.

[0096] Each of the multiple heat transfer tubes 10 has a tube wall 11 in which a heat transfer flow path P1a is provided through an internal space through which a fluid circulates, and the tube wall 11 has tube side wall portions 10a etc. facing each other in a first direction D1, and a first through hole 30 into which a header tube 80 is inserted is formed in the tube side wall portions 10a etc. In the heat exchanger 100, the header section 50 can be formed by inserting the header tube 80 into the first through hole 30, so that manufacturing is easier and costs can be reduced compared to a configuration in which the header section is provided outside the heat transfer tube group 15.

[0097] In addition, the piping 70 does not communicate with the internal spaces of the heat transfer tubes 10, and heat exchange is performed between the refrigerant flowing inside the piping 70 and the refrigerant flowing inside the heat transfer tubes 10. The heat exchanger 100 does not need to have a configuration having the function of an internal heat exchanger outside the heat transfer tubes 10 by having the piping 70, and by incorporating the function of an internal heat exchanger, it does not need to have a header section larger than a header section that does not have the function. Therefore, the heat exchanger 100 can be made smaller in size than a heat exchanger having the function outside the heat transfer tube group 15 while improving heat exchange efficiency by performing the function as an internal heat exchanger by the piping 70. Therefore, the heat exchanger 100 can be installed in a smaller space than a heat exchanger having the function outside the heat transfer tube group 15.

[0098] The air conditioner 200 also includes a compressor 201, an outdoor heat exchanger 203 configured with the heat exchanger 100, an expansion valve 204 that reduces the pressure of the refrigerant flowing therethrough, and an indoor heat exchanger 205 that exchanges heat between the indoor air and the refrigerant flowing therethrough. The air conditioner 200 includes the heat exchanger 100, and thus can achieve the effects of the heat exchanger 100 described above.

[0099] The air conditioner 200 also includes a compressor 201, an outdoor heat exchanger 203 composed of a heat exchanger 100, an expansion valve 204, and an indoor heat exchanger 205. The air conditioner 200 configures a refrigerant circuit 250 including a main circuit 251 and a branch circuit 252. The main circuit 251 is a circuit in which the compressor 201, the outdoor heat exchanger 203, the expansion valve 204, and the indoor heat exchanger 205 are connected via refrigerant piping 255, and in which the refrigerant circulates. The branch circuit 252 is connected to the piping 70 of the outdoor heat exchanger 203, and is a circuit composed of the refrigerant piping 255 in which the refrigerant that branches off from the main circuit 251 and merges with the main circuit 251 via the piping 70 flows.

[0100] By having the above configuration, the air conditioning apparatus 200 can achieve the following effects when the heat exchanger 100 functions as the condenser 221 as shown in Fig. 7. The air conditioning apparatus 200 causes a portion of the refrigerant flowing out from the outlet of the condenser 221 to be bypassed by the branch circuit 252, making it into a low-temperature, low-pressure state, and exchanges heat with the high-pressure refrigerant flowing near the header section 50 at the outlet of the condenser 221. In such a case, the air conditioning apparatus 200 makes it easier to achieve a degree of supercooling at the outlet portion of the condenser 221, and increases the gas-liquid two-phase region in the condenser 221, thereby improving the heat exchanger performance.

[0101] Furthermore, the air conditioner 200 can achieve the following effects when the branch circuit 252 causes a portion of the refrigerant flowing out from the outlet of the condenser 221 to bypass and exchange heat near the header section 50 at the outlet of the condenser 221, and merges with the main circuit 251 flowing into the compressor 201. With this configuration, the air conditioner 200 can suppress performance degradation due to increased pressure loss in the evaporator 222 by reducing the amount of refrigerant that flows into the evaporator 222 via the expansion valve 204 after flowing out of the outlet of the condenser 221.

[0102] Furthermore, the air conditioner 200 can achieve the following effects when the heat exchanger 100 functions as the condenser 221 during defrost operation as shown in Fig. 8. When the air conditioner 200 is operating under low outside air temperature conditions and the heat exchanger 100 frosts and the operation is switched to defrost operation, part of the refrigerant, which is hot gas ejected from the compressor 201, is caused to flow through the heat exchanger 100 via the branch circuit 252, thereby promoting melting of the frost in the frosted portion and improving low-temperature performance.

[0103] Furthermore, by having the above configuration, the air conditioner 200 can achieve the following effects when the heat exchanger 100 functions as the condenser 221 during defrost operation as shown in Fig. 9. When the air conditioner 200 is operating under low outside air temperature conditions and frost forms on the heat exchanger 100, it is possible to promote melting of the frost on the frosted portion by causing a portion of the high-temperature, high-pressure refrigerant to flow from just before the inlet of the condenser 221 to the heat exchanger 100 via the branch circuit 252, thereby improving low-temperature performance.

[0104] Embodiment 2 FIG. 11 is a perspective view showing a schematic configuration of a heat exchanger 100 according to the second embodiment. FIG. 12 is a vertical cross-sectional view of a modified example of the heat exchanger 100 according to the second embodiment. Note that FIGS. 11 and 12 show a part of the heat exchanger 100. Also, in FIGS. 11 and 12, a part of the second direction D2 is omitted. In FIGS. 11 and 12, the direction of the refrigerant flow is indicated by a solid white arrow. The heat exchanger 100 according to the second embodiment is obtained by modifying the configuration of the piping 70 in the heat exchanger 100 according to the first embodiment. Note that the same reference numerals are used for components having the same functions and actions as those in the first embodiment, and the description thereof will be omitted.

[0105] At least one or more communication holes 72 communicating with the internal spaces of the heat transfer tubes 10 are formed in the pipe 70 of the heat exchanger 100 according to the second embodiment. In the heat exchanger 100, a part of the refrigerant flowing through the interiors of the heat transfer tubes 10 flows into the interior of the pipe 70 through the communication holes 72. The communication holes 72 are provided in a lower portion of the pipe 70 in the direction of gravity. An opening diameter of the communication hole 72 is smaller than the inner diameters of the heat transfer tube 10 in the first direction D1 and the third direction D3. That is, the communication holes 72 are formed in the internal space of the heat transfer tube 10.

[0106] The piping 70 serves as a gas-liquid separator that extracts only gas (gas phase) from the refrigerant in a two-phase gas-liquid state flowing inside the heat transfer tube 10. The gas (gas phase) refrigerant extracted from the refrigerant in a two-phase gas-liquid state flowing inside the heat transfer tube 10 flows inside the piping 70. The heat exchanger 100 has a gas-liquid separation function that extracts the gas component by the piping 70 and flows the remaining liquid into the heat transfer tube 10, and can achieve higher efficiency than when the piping 70 is not provided.

[0107] The gas-liquid separator portion of the heat exchanger 100 may be a part or the entirety of the heat transfer tube group 15. When the gas-liquid separator portion of the heat exchanger 100 is a part of the heat transfer tube group 15, for example, the heat exchanger 100 has a portion of the piping 70 that does not have a communication hole 72, and this portion penetrates the inside of the heat transfer tube 10. The portion of the piping 70 that does not have the communication hole 72 does not communicate with the internal space of the heat transfer tube 10.

[0108] Fig. 13 is a refrigerant circuit diagram during heating operation of an air conditioner 200 equipped with a heat exchanger 100 of embodiment 2. As shown in Fig. 13, the heat exchanger 100 constitutes a part of a refrigerant circuit 250 through which a refrigerant circulates in the air conditioner 200. The configuration of a main circuit 251 in the refrigerant circuit 250 of the air conditioner 200 of embodiment 2 is similar to the configuration of the main circuit 251 of the air conditioner 200 of embodiment 1.

[0109] The air-conditioning device 200 is composed of a compressor 201, a flow path switching device 202 that switches the flow path of the refrigerant, and a heat exchanger 100, and has an evaporator 222 that exchanges heat between the outdoor air and the refrigerant flowing inside. The air-conditioning device 200 also has an expansion valve 204 that reduces the pressure of the refrigerant flowing inside, and a condenser 221 that exchanges heat between the indoor air and the refrigerant flowing inside.

[0110] The refrigerant circuit 250 includes a main circuit 251 and a junction circuit 254. The main circuit 251 is a circuit in which the compressor 201, the evaporator 222, the expansion valve 204, and the condenser 221 are connected via refrigerant piping 255, and the refrigerant circulates. The junction circuit 254 is a circuit that is connected to the piping 70 of the evaporator 222, and is constituted by the refrigerant piping 255 that causes the refrigerant to flow into the refrigerant piping 255 of the main circuit 251 at a position downstream of the refrigerant outlet of the evaporator 222.

[0111] One end of the junction circuit 254 of the air conditioning device 200 is connected to the pipe 70 of the evaporator 222, and the other end is connected to the main circuit 251 on the suction side of the compressor 201. The main circuit 251 on the suction side of the compressor 201 is the main circuit 251 in the portion between the evaporator 222 and the flow path switching device 202 during heating operation, in other words, the main circuit 251 in the portion between the evaporator 222 and the compressor 201 during heating operation.

[0112] The junction circuit 254 is provided with a fixed fluid resistance 210 and a pipe 70. The fixed fluid resistance 210 and the pipe 70 are provided in the order of the pipe 70 and the fixed fluid resistance 207 in the flow direction of the refrigerant flowing through the junction circuit 254 during heating operation. In the flow direction of the refrigerant flowing through the junction circuit 254 during heating operation, the fixed fluid resistance 210 is provided downstream of the pipe 70. During heating operation, the heat exchanger 100 extracts a part of the gas component from the refrigerant in a gas-liquid two-phase state in the heat exchanger 100, and the refrigerant in a gas (vapor phase) state flows through the junction circuit 254 and is decompressed by the fixed fluid resistance 210 so as to be uniform with the refrigerant sucked into the compressor 201.

[0113] When the heat exchanger 100 functions as an evaporator 222, the air conditioning device 200 extracts a portion of the gas-liquid two-phase refrigerant flowing through the heat transfer tube 10 from the communication hole 72, and merges the extracted refrigerant at any position in the refrigerant piping 255 downstream of the outlet of the heat exchanger 100.

[0114] [Effects of the heat exchanger 100] The piping 70 of the second embodiment is formed with at least one or more communication holes 72 communicating with the internal space of the heat transfer tubes 10, and a part of the refrigerant flowing through the heat transfer tubes 10 flows into the piping 70 through the communication holes 72. The heat exchanger 100 has the piping 70, and can extract gas (gas phase) from the refrigerant in a gas-liquid two-phase state flowing through the heat transfer tube 10, and can play the role of a gas-liquid separator. The heat exchanger 100 uses the piping 70 to extract only gas (gas phase) from the refrigerant in a gas-liquid two-phase state flowing through the heat transfer tube 10, and can exchange more heat with the liquid phase refrigerant, which has a higher heat exchange efficiency than the gas refrigerant, in the heat exchanger 100, and thus the heat exchanger performance is improved. The heat exchanger 100 uses the piping 70 having the communication holes 72 to extract the gas refrigerant, which has a large pressure loss, and thus the pressure loss of the heat exchanger 100 is reduced, and the heat exchanger performance is improved.

[0115] The heat exchanger 100 can be provided with a configuration having a function as a gas-liquid separator within the configuration range of the heat transfer tube group 15 by the piping 70 having the communication hole 72. That is, the heat exchanger 100 does not need to provide a configuration having a function as a gas-liquid separator outside the heat transfer tube 10, and by incorporating the function as a gas-liquid separator, it is not necessary to provide a header section larger than a header section not having the function. Therefore, the heat exchanger 100 can be made smaller in size than a heat exchanger having the function outside the heat transfer tube group 15 while improving heat exchange efficiency by performing the function as a gas-liquid separator by the piping 70 having the communication hole 72. Therefore, the heat exchanger 100 can be installed in a smaller space than a heat exchanger having the function outside the heat transfer tube group 15.

[0116] Moreover, the communication hole 72 is provided in a lower portion of the pipe 70 in the direction of gravity. By having this configuration, the heat exchanger 100 makes it easier for gas refrigerant to flow into the pipe 70 through the communication hole 72 than for liquid refrigerant, thereby improving the function as a gas-liquid separator.

[0117] Moreover, the air conditioner 200 includes a compressor 201, an outdoor heat exchanger 203 configured by the heat exchanger 100, an expansion valve 204 that reduces the pressure of the refrigerant flowing therethrough, and an indoor heat exchanger 205 that exchanges heat between the indoor air and the refrigerant flowing therethrough. The air conditioner 200 includes the heat exchanger 100 of the second embodiment, and therefore can achieve the effects of the heat exchanger 100 described above.

[0118] The air conditioner 200 also includes a compressor 201, an evaporator 222 configured with a heat exchanger 100, an expansion valve 204, and a condenser 221. The air conditioner 200 configures a refrigerant circuit 250 including a main circuit 251 and a junction circuit 254. The main circuit 251 is a circuit in which the compressor 201, the evaporator 222, the expansion valve 204, and the condenser 221 are connected via refrigerant piping 255, and in which the refrigerant circulates. The junction circuit 254 is connected to the piping 70 of the evaporator 222, and is a circuit configured by the refrigerant piping 255 that causes the refrigerant to flow into the refrigerant piping 255 of the main circuit 251 at a position downstream of the refrigerant outlet of the evaporator 222.

[0119] The heat exchanger 100 extracts only gas (gas phase) from the refrigerant in a gas-liquid two-phase state by the piping 70 and causes it to flow into the refrigerant piping 255 of the main circuit 251 downstream of the outlet of the heat exchanger 100, thereby increasing the amount of liquid phase refrigerant inside the heat transfer tube 10. The heat exchanger 100 can exchange more heat with the liquid phase refrigerant, which has a higher heat exchange efficiency than the gas refrigerant, compared to when the piping 70 is not used, and therefore the heat exchanger performance can be improved.

[0120] Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments. For example, the present disclosure may be configured by combining the respective embodiments. [Explanation of symbols]

[0121] 10 heat transfer tube, 10a tube side wall portion, 10b tube side wall portion, 10c connection wall portion, 10d connection wall portion, 10e opening end, 11 tube wall, 12 connection portion, 12a connection protrusion portion, 12b connection protrusion portion, 12c connection protrusion portion, 12d connection protrusion portion, 15 heat transfer tube group, 20 tube sealing portion, 30 first through hole, 30a first through hole, 30b first through hole, 30c first through hole, 30d first through hole, 40 second through hole, 50 header portion, 51 first header portion, 51a inlet / outlet, 52 second header portion, 52a inlet / outlet, 70 piping, 72 communication hole, 80 header pipe, 82 hole, 100 heat exchanger, 200 air conditioning device, 201 compressor, 202 flow path switching device, 203 Outdoor heat exchanger, 203a outdoor fan, 204 expansion valve, 205 indoor heat exchanger, 205a indoor fan, 206 check valve, 207 fixed fluid resistance, 208 bypass valve, 209 bypass valve, 210 fixed fluid resistance, 221 condenser, 222 evaporator, 231 outdoor unit, 232 indoor unit, 250 refrigerant circuit, 251 main circuit, 252 branch circuit, 254 junction circuit, 255 refrigerant piping, Ax pipe axis, D1 first direction, D2 second direction, D3 third direction, P1 flow path, P1a heat transfer flow path, P1b header flow path, P1c header flow path, P2 flow path, Sg hollow portion.

Claims

1. a plurality of heat transfer tubes arranged in a first direction, each extending in a second direction intersecting the first direction, both ends of which are sealed in the second direction, through which a refrigerant flows in the second direction; a pipe passing through the plurality of heat transfer tubes in the first direction, the pipe having a refrigerant flowing therethrough; Equipped with Each of the plurality of heat transfer tubes has a plurality of first through holes formed on the inner side of both end portions in the second direction and communicating an internal space of each of the plurality of heat transfer tubes with the outside; a pair of second through holes formed opposite to each other in the first direction; is formed, The plurality of heat transfer tubes include: a first header portion and a second header portion which communicate a refrigerant between the internal spaces of the plurality of heat transfer tubes and serve as an inlet and outlet for the refrigerant of the heat transfer tube group constituted by the plurality of heat transfer tubes are formed by connecting the plurality of first through holes of adjacent heat transfer tubes among the plurality of heat transfer tubes, The first header portion and the second header portion each include a width of the heat transfer tube in a third direction perpendicular to the first direction and the second direction is smaller than the width of the heat transfer tube, The piping, a heat exchanger that is inserted into the pair of second through holes and penetrates the internal space of the plurality of heat transfer tubes through which refrigerant flows in the portion between the first header portion and the second header portion;

2. In the second direction, the first header portion is provided on one end side of the heat transfer tube, and the second header portion is provided on the other end side of the heat transfer tube, The piping includes: The heat exchanger according to claim 1 , wherein the first header portion and the second header portion are disposed closer to each other.

3. The plurality of heat transfer tubes include Among the plurality of heat transfer tubes, a plurality of connection portions directly connecting the plurality of first through holes of the adjacent heat transfer tubes are provided, Each of the first header portion and the second header portion is The heat exchanger according to claim 1 , which is constituted by a plurality of said connecting portions.

4. Each of the plurality of heat transfer tubes is a tube wall having a heat transfer flow path through which a fluid flows in the internal space; The tube wall has tube side wall portions facing each other in the first direction, and the first through hole is formed in the tube side wall portions, The adjacent heat transfer tubes have the connection portion that connects the tube walls and communicates the heat transfer flow paths inside the tube walls, 4. The heat exchanger according to claim 3, wherein the connecting portion is formed on at least one of the opposing tube side wall portions of the adjacent heat transfer tubes, and is configured as a connecting protrusion protruding in the first direction from a peripheral portion of the first through hole.

5. The plurality of heat transfer tubes include a plurality of header tubes that are inserted into the plurality of first through holes and connect the plurality of first through holes of the adjacent heat transfer tubes among the plurality of heat transfer tubes; Each of the first header portion and the second header portion is the header pipe is inserted into the first through hole, The heat exchanger according to claim 1 , wherein the header pipe is formed with a plurality of holes communicating with the internal spaces of the respective heat transfer pipes.

6. Each of the plurality of heat transfer tubes is a tube wall having a heat transfer flow path through which a fluid flows in the internal space; 6. The heat exchanger according to claim 5, wherein the tube wall has tube side wall portions facing each other in the first direction, and the first through holes into which the header tubes are inserted are formed in the tube side wall portions.

7. The piping includes: The internal spaces of the heat transfer tubes are not in communication with each other, 7. The heat exchanger according to claim 1, wherein heat is exchanged between a refrigerant flowing inside the pipe and a refrigerant flowing inside the plurality of heat transfer tubes.

8. The piping includes:

7. The heat exchanger according to claim 1, wherein at least one or more communication holes are formed in communication with the internal spaces of the heat transfer tubes, and a portion of the refrigerant flowing through the heat transfer tubes flows into the inside of the piping through the communication holes.

9. The communication hole is 9. The heat exchanger according to claim 8, wherein the heat exchanger is provided at a lower portion of the pipe in the direction of gravity.

10. A compressor; An outdoor heat exchanger comprising the heat exchanger according to any one of claims 1 to 6, which exchanges heat between outdoor air and a refrigerant flowing therein; an expansion valve that reduces the pressure of the refrigerant flowing therein; an indoor heat exchanger that exchanges heat between indoor air and a refrigerant flowing therein; An air conditioning device equipped with the above.

11. A compressor; An outdoor heat exchanger comprising the heat exchanger according to any one of claims 1 to 6, which exchanges heat between outdoor air and a refrigerant flowing therein; an expansion valve that reduces the pressure of the refrigerant flowing therein; an indoor heat exchanger that exchanges heat between indoor air and a refrigerant flowing therein; Equipped with a main circuit in which the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger are connected via a refrigerant piping and in which a refrigerant circulates; a branch circuit including a refrigerant pipe connected to the piping of the outdoor heat exchanger, the refrigerant branching from the main circuit and passing through the piping to join the main circuit; An air conditioning apparatus comprising a refrigerant circuit including:

12. A compressor; An evaporator comprising the heat exchanger according to claim 8, which exchanges heat between outdoor air and a refrigerant flowing therein; an expansion valve that reduces the pressure of the refrigerant flowing therein; a condenser that exchanges heat between indoor air and a refrigerant flowing therein; Equipped with a main circuit in which the compressor, the evaporator, the expansion valve, and the condenser are connected via a refrigerant piping and in which a refrigerant circulates; a confluence circuit configured by the refrigerant piping connected to the piping of the evaporator and causing the refrigerant to flow into the refrigerant piping of the main circuit at a position downstream of a refrigerant outlet of the evaporator; An air conditioning apparatus comprising a refrigerant circuit including:

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