Heat exchanger

Abstract

To provide a heat exchanger which can suppress odor while maintaining water drainage property of a fin in a state where condensed water evaporates all at once.SOLUTION: A heat exchanger 1 includes: a tube 10 in which a first fluid flows; and a fin 20 formed by bending a plate-like member and promotes heat exchange between a second fluid that flows outside of the tube 10 and the first fluid. An outer surface 21 of the fin 20 includes a first region 21A and a second region 21B that is more hydrophilic than the first region 21A. A groove 22 is formed in the second region 21B that improves hydrophilicity of the outer surface 21. The second region 21B is arranged adjacent to a part of the region 12A of a bonding part 12 between the tube 10 and the fin 20.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a heat exchanger. [Background technology]

[0002] Conventionally, a heat exchanger including a first fluid flowing through a tube and a fin for promoting heat exchange between the first fluid and a second fluid flowing outside the tube is known. In the heat exchanger, condensed water is generated depending on the load condition of the heat exchanger, and the condensed water may accumulate on the outer surface of the fin. Therefore, for example, Patent Document 1 proposes a heat exchanger in which grooves are provided on the entire surface of the fin to improve the drainage of the fin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-002589 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the refrigeration cycle including the heat exchanger is operating at high load, a large amount of condensed water is generated in the heat exchanger. Therefore, the condensed water generated on the outer surface of the fin forms a water film all over the surface and is easily connected, and is easily drained into the tube through the groove.

[0005] In contrast, when the refrigeration cycle is operating at low load, the amount of condensed water generated in the heat exchanger is small. Therefore, the condensed water that runs down the tubes and that accumulates at the joints between the fins and the tubes is drawn into the center of the fins by capillary action in the grooves, and the condensed water remains on the outer surface of the fins. In other words, the grooves, which are intended to improve the drainage of condensed water, actually reduce drainage when the refrigeration cycle is operating at low load.

[0006] Furthermore, when the compressor is turned on and off during low load operation of the refrigeration cycle, or when the pressure is raised to a low level to save power, the temperature of the fins rises and the condensed water remaining on the outer surface of the fins evaporates all at once, causing the odorous components contained in the condensed water to be released all at once, which may result in the generation of odors.

[0007] In view of the above, an object of the present invention is to provide a heat exchanger that can suppress odors while ensuring the drainage properties of the fins in a situation where condensed water evaporates all at once. [Means for solving the problem]

[0008] In order to achieve the above object, in the invention described in claim 1, the heat exchanger includes a tube (10) through which a first fluid flows, and a fin (20) formed by bending a plate-like member and promoting heat exchange between the first fluid and a second fluid flowing outside the tube.

[0009] The outer surface (21) of the fin has a first region (21A) and a second region (21B) that is more hydrophilic than the first region.

[0010] The second region has grooves (22) formed therein to improve the hydrophilicity of the outer surface.

[0011] The second region is disposed adjacent to a partial region (12A) of the joint (12) between the tube and the fin.

[0012] According to this, the only highly hydrophilic area of ​​the outer surface of the fin adjacent to the joint between the tube and the fin is the second area, so the area into which the condensed water (Wc) is drawn can be made smaller than when the condensed water (Wc) is drawn into the entire area adjacent to the joint by the groove.

[0013] Therefore, when the amount of condensed water generated is small, the evaporation rate of the condensed water in the area of ​​the outer surface of the fin adjacent to the joint between the tube and the fin can be slowed down. Therefore, when the condensed water evaporates all at once, the odorous components contained in the condensed water can be prevented from being released all at once. Also, when the amount of condensed water generated is large, the condensed water can be drained into the tube through the grooves of the fin.

[0014] Therefore, in a situation where the condensed water evaporates all at once, it is possible to suppress odors while ensuring the drainage properties of the fins.

[0015] In addition, the reference symbols in parentheses for each means described in this column and in the claims indicate the correspondence with the specific means described in the embodiments described later. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of a heat exchanger according to a first embodiment. [Diagram 2] FIG. 2 is an enlarged perspective view of a portion of the tubes and fins of the heat exchanger of FIG. 1. [Diagram 3] FIG. 3 is a view taken along the arrow III in FIG. 2. [Figure 4] FIG. 4 is an enlarged plan view showing a schematic diagram of a groove by enlarging a part of a joint between a tube and a fin in a second region of an outer surface of the fin in the first embodiment. [Diagram 5] 5 is a cross-sectional view showing the VV cross section of FIG. 4. [Figure 6] This figure is for explaining the high drainage mode in which a large amount of condensation water is generated. The upper part shows the amount of condensation water corresponding to the position in the air passage direction, the middle part shows the drainage mode when a groove portion is formed on part of the outer surface of the fin, and the lower part shows the drainage mode when a groove portion is not formed on the outer surface of the fin. [Figure 7]This figure explains how condensed water generated in a heat exchanger evaporates when grooves are provided on the entire outer surface of the fin, when grooves are provided on only a part of the outer surface of the fin, and when no grooves are provided on the outer surface of the fin. [Figure 8] This figure shows the relationship between the evaporation rate of condensed water and the time it takes for the evaporation of condensed water to finish when grooves are provided on the entire outer surface of the fin, when grooves are provided on only a portion of the outer surface of the fin, and when no grooves are provided on the outer surface of the fin. [Figure 9] 11 is a perspective view showing how odorous components are released in large amounts when grooves are formed over the entire outer surface of a fin. FIG. [Figure 10] 11 is a perspective view showing how odorous components are released in small amounts when a groove is formed in a part of the outer surface of a fin. FIG. [Figure 11] FIG. 11 is a plan view showing a schematic diagram of a groove portion formed in a second region in the second embodiment. [Figure 12] FIG. 11 is a plan view showing a schematic diagram of a groove portion formed in a second region in the second embodiment. [Figure 13] FIG. 11 is a plan view showing a schematic diagram of a groove portion formed in a second region in the second embodiment. [Figure 14] FIG. 11 is a diagram showing a groove portion formed in a second region in the second embodiment. [Figure 15] FIG. 11 is an enlarged cross-sectional view showing some of the grooves formed in the first region and the second region in the third embodiment. [Figure 16] FIG. 11 is an enlarged plan view showing some of the grooves formed in the first region and the second region in the third embodiment. [Figure 17] FIG. 11 is an enlarged plan view showing some of the grooves formed in the first region and the second region in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

[0018] (First embodiment) The heat exchanger according to the present embodiment is used, for example, as an evaporator constituting a part of a refrigeration cycle for conditioning the air in a vehicle cabin. The refrigeration cycle includes, for example, a compressor, a condenser, an expansion valve, and an evaporator. The evaporator is disposed inside an air conditioning case through which air flows to be blown into the vehicle cabin.

[0019] Therefore, the evaporator exchanges heat between the low-pressure refrigerant as the first fluid of the refrigeration cycle decompressed by the expansion valve and the blown air as the second fluid flowing through the air conditioning case, and cools the blown air by having the low-pressure refrigerant absorb heat from the blown air. In other words, the evaporator is a cooling heat exchanger that cools air by using the latent heat of evaporation of the refrigerant.

[0020] Hereinafter, the first embodiment will be described with reference to Fig. 1 to Fig. 10. As shown in Fig. 1 and Fig. 2, the heat exchanger 1 includes a plurality of tubes 10, a plurality of fins 20, a first tank portion 30, a second tank portion 40, an outer frame member 50, and a piping connection member 60. These members are made of, for example, an aluminum alloy, and the respective members are joined together by brazing. An arrow DRg in Fig. 1 indicates the up-down direction DRg of the heat exchanger 1.

[0021] As will be described later, a plurality of grooves 22 (see Figs. 4 and 5) are formed on the outer surface 21 of the fin 20. However, since the grooves 22 are extremely small compared to the size of the fin 20, they are not shown in Figs. 2 and 3. This also applies to other figures showing the fin 20, described later, except for the figures showing the grooves 22 in an enlarged manner.

[0022] As shown in Fig. 3, the multiple tubes 10 are arranged at predetermined intervals in the tube arrangement direction DRst. Air passing through the heat exchanger 1 flows between the multiple tubes 10. That is, the air flows between adjacent tubes 10 in the tube arrangement direction DRst. Between the tubes 10, the air flows with one side of the air passing direction AF as the upstream side (windward) and the other side of the air passing direction AF as the downstream side (leeward). In other words, the air passing direction AF is the second fluid flow direction.

[0023] Moreover, the air passing through the heat exchanger 1 is cooled by the refrigerant while flowing between the tubes 10, generating condensed water. In other words, the air passing through the heat exchanger 1 is a gas that generates condensed water by heat exchange with the refrigerant.

[0024] The tubes 10 are flat tubes having a flat cross-sectional shape with the tube arrangement direction DRst as the short side direction and the air passage direction AF as the long side direction. The tubes 10 are arranged in a first arrangement group 10A and a second arrangement group 10B in the tube arrangement direction DRst that intersects with the tube extension direction DRt. The tube extension direction DRt is the direction in which the tubes 10 extend.

[0025] The first array group 10A and the second array group 10B are arranged in the air passing direction AF. That is, the tubes 10 are arranged in two rows, one on one side and the other on the air passing direction AF. In this embodiment, in the air passing direction AF, the first array group 10A is located on the upstream side of the air flow, and the second array group 10B is located on the downstream side of the air flow.

[0026] As shown in FIG. 1, each of the multiple tubes 10 is formed to extend linearly from one end to the other end along a tube extension direction DRt. A refrigerant flows inside each tube 10. The tube extension direction DRt does not necessarily have to coincide with the up-down direction DRg. In this embodiment, the tube extension direction DRt coincides with the up-down direction DRg. Each of the tubes 10 in this embodiment extends in the up-down direction DRg, i.e., the vertical direction DRg.

[0027] The air passing direction AF, the tube arrangement direction DRst, and the tube extension direction DRt are directions that intersect with each other, and strictly speaking, are directions that are perpendicular to each other.

[0028] The upper ends of the multiple tubes 10 are inserted into the first tank portion 30, and the lower ends are inserted into the second tank portion 40. The first tank portion 30 and the second tank portion 40 distribute the refrigerant to the multiple tubes 10 and collect the refrigerant flowing in from the multiple tubes 10.

[0029] Each of the tank parts 30, 40 is formed in a tubular shape using the same material as the tube 10. Each of the tank parts 30, 40 is formed in a shape extending in the tube arrangement direction DRst. Note that the term "tubular" includes not only a cylindrical shape but also a polygonal tube shape such as a rectangular tube shape.

[0030] An internal space is formed inside the first tank portion 30, through which the refrigerant of the refrigeration cycle flows in and out. The internal space of the first tank portion 30 is divided into an upstream side and a downstream side in the air passing direction AF. That is, the first tank portion 30 has a first downwind tank portion 31 located downstream in the air passing direction AF, and a first upwind tank portion 32 located upstream in the air passing direction AF.

[0031] The first windward tank portion 32 is connected to and communicates with one ends of the multiple windward tubes 10 on the upstream side of the first tank portion 30 in the air passing direction AF. The first windward tank portion 32 functions as a collection tank portion that collects the refrigerant passing through the multiple windward tubes 10.

[0032] On the other hand, the first downwind tank portion 31 is connected to and communicates with one ends of the multiple downwind tubes 10 on the downstream side of the first tank portion 30 in the air passing direction AF. The first downwind tank portion 31 functions as a distribution tank portion that distributes the refrigerant to the multiple downwind tubes 10.

[0033] In the heat exchanger 1 according to the first embodiment, the second tank portion 40 is disposed on the lower side in the up-down direction DRg of the heat exchanger 1. The second tank portion 40 is joined to the lower end portions of the tubes 10 by brazing.

[0034] An internal space is formed inside the second tank portion 40, through which the refrigerant of the refrigeration cycle flows in and out. The internal space of the second tank portion 40 is divided into a windward side and a leeward side. That is, the second tank portion 40 has a second leeward tank portion 41 located downstream in the air passing direction AF, and a second upwind tank portion 42 located upstream in the air passing direction AF.

[0035] The second windward tank portion 42 is connected to and communicates with the other ends of the multiple windward tubes 10 on the upstream side of the second tank portion 40 in the air passing direction AF. The second windward tank portion 42 functions as a distribution tank portion that distributes the refrigerant to the multiple windward tubes 10.

[0036] On the other hand, the second downwind tank unit 41 is connected to and communicates with the other ends of the multiple downwind tubes 10 on the downstream side of the second tank unit 40 in the air passing direction AF. The second downwind tank unit 41 functions as a collection tank unit that collects the refrigerant that has passed through the multiple downwind tubes 10.

[0037] Moreover, the second leeward tank portion 41 is connected to the second upwind tank portion 42 inside the second tank portion 40. Therefore, the second tank portion 40 can supply the refrigerant collected in the second downwind tank portion 41 to the second upwind tank portion 42, and distribute the refrigerant to each tube 10 on the windward side in the second upwind tank portion 42.

[0038] Since air flows between the multiple tubes 10, the gaps formed between the tubes 10 serve as air passages through which the air flows. The fins 20 are provided in the air passages. In other words, the fins 20 are disposed between adjacent tubes 10 in the tube arrangement direction DRst. Therefore, the fins 20 are outer fins provided on the outside of the tubes 10.

[0039] The fins 20 promote heat exchange between the refrigerant flowing inside the tubes 10 and the air flowing between the tubes 10. Specifically, the fins 20 increase the heat transfer area between the refrigerant flowing inside the tubes 10 and the air flowing outside the tubes 10, thereby improving the efficiency of heat exchange between the refrigerant and the air.

[0040] In the tube arrangement direction DRst, a pair of outer frame members 50 are provided outside the portion where the multiple tubes 10 and the multiple fins 20 are alternately arranged. A pipe connection member 60 is fixed to one of the pair of outer frame members 50.

[0041] The pipe connection member 60 is a member for connecting refrigerant pipes in a refrigeration cycle. The pipe connection member 60 is joined by brazing to a side surface of one end of the first tank portion 30 in the tube arrangement direction DRst.

[0042] The pipe connection member 60 has a refrigerant inlet 61 through which a refrigerant is supplied, and a refrigerant outlet 62 through which the refrigerant is discharged. The outlet side of an expansion valve in a refrigeration cycle is connected to the refrigerant inlet 61 via a refrigerant pipe. A refrigerant inlet passage (not shown) is connected to the refrigerant inlet 61. The refrigerant inlet passage is formed inside the pipe connection member 60, and connects the refrigerant inlet 61 to the internal space of the first downwind tank portion 31.

[0043] On the other hand, the suction port side of the compressor in the refrigeration cycle is connected to the refrigerant outlet 62 via a refrigerant piping. A refrigerant outflow passage (not shown) is connected to the refrigerant outlet 62. The refrigerant outflow passage is formed inside the piping connection member 60 and connects the refrigerant outlet 62 to the internal space of the first windward tank portion 32.

[0044] The refrigerant flowing into the first tank portion 30 from the refrigerant inlet 61 flows through the internal space of each tank portion 30, 40 and the multiple tubes 10 along a predetermined path, and flows out from the refrigerant outlet 62. At that time, the air flowing through the air passage in which the fins 20 are provided is cooled by the latent heat of evaporation of the refrigerant flowing through each tank portion 30, 40 and the multiple tubes 10.

[0045] The fins 20 are components that promote heat exchange between the air flowing outside the tubes 10 and the refrigerant. As shown in Fig. 2, the fins 20 are formed by bending a plate-like member. Specifically, the fins 20 are bent to form a continuous wave shape in the tube extension direction DRt. The fins 20 are, for example, corrugated fins.

[0046] The fin 20 has a plurality of bent portions 23 and a plurality of fin main body portions 24. The plurality of bent portions 23 form the top portions of the waveform of the fin 20. In addition, since the bent portions 23 form the top portions of the waveform of the fin 20, they are also referred to as fin TOP portions.

[0047] The bent portions 23 are joined to the tube wall surfaces 11, which are the side surfaces of the tubes 10 facing the tube arrangement direction DRst. That is, of the surfaces on both sides of the bent portions 23 in the plate thickness direction, the surface opposite to the side joined to the tubes 10 is exposed to the air passages formed between the tubes 10. The joining between the bent portions 23 and the tubes 10 is specifically a brazing joining.

[0048] The fin main body 24 is disposed between adjacent folded portions 23 along the wave shape of the fin 20, and is connected to each of the folded portions 23 so as to connect the folded portions 23. Here, "adjacent folded portions 23 along the wave shape" refers to adjacent folded portions 23 on a virtual wave curve when a virtual wave curve is imagined along the wave shape.

[0049] The fin main body 24 is bent at both ends of the fin main body 24 in the tube arrangement direction DRst. That is, the fin main body 24 has a pair of curved portions 24A provided at both ends of the fin main body 24 in the tube arrangement direction DRst, and a main body intermediate portion 24B provided between the pair of curved portions 24A. Each of the pair of curved portions 24A is curved and connected to the adjacent bent portions 23 on both sides of the fin main body 24.

[0050] The fin body 24 also has a plurality of louvers 24C each formed by cutting and raising a portion of the fin body 24. The plurality of louvers 24C are arranged side by side in the air passage direction AF.

[0051] The multiple louvers 24C are included in a main body intermediate portion 24B of the fin main body portion 24. The louvers 24C have a louver main body portion 24D including a central portion of the louvers 24C in the tube arrangement direction DRst, a louver one end portion 24E, and a louver other end portion 24F.

[0052] Louver main body 24D has a flat plate shape inclined with respect to the air passage direction AF, and guides air along louver main body 24D. In other words, a gap through which air can pass is formed between louver main body portions 24D of louvers 24C adjacent to each other in the air passage direction AF.

[0053] The louver one end 24E is in the form of a plate extending from the louver main body 24D to one side in the tube arrangement direction DRst, and is provided at one end of the louver 24C in the tube arrangement direction DRst. The louver one end 24E is formed such that the plate thickness direction of the louver one end 24E intersects with the plate thickness direction of the louver main body 24D.

[0054] Additionally, the louver one end 24E is connected to the curved portion 24A constituting the area around the louvers 24C of the fin main body 24 on the side opposite the louver main body 24D in the tube arrangement direction DRst. The curved portion 24A to which the louver one end 24E is connected is the one on one side in the tube arrangement direction DRst of a pair of curved portions 24A arranged side by side with the main body intermediate portion 24B therebetween.

[0055] The louver other end 24F is in the form of a plate extending from the louver main body 24D to the other side in the tube arrangement direction DRst, and is provided at the end of the louver 24C on the other side in the tube arrangement direction DRst. The louver other end 24F is formed such that the plate thickness direction of the louver other end 24F intersects with the plate thickness direction of the louver main body 24D.

[0056] Additionally, the louver other end 24F is connected to the curved portion 24A constituting the portion around the louvers 24C of the fin main body 24 on the side opposite the louver main body 24D in the tube arrangement direction DRst. The curved portion 24A to which the louver other end 24F is connected is the curved portion 24A on the other side in the tube arrangement direction DRst of the pair of curved portions 24A arranged side by side with the main body intermediate portion 24B therebetween.

[0057] All the louvers 24C of one fin body 24 are divided into a plurality of louver groups. Each louver group is composed of a plurality of louvers 24C in which the louver body 24D is provided parallel to each other with a predetermined interval. In this case, the air passing through the heat exchanger 1 is guided by the plurality of louver groups so as to meander as indicated by the arrow FLf in FIG. 2. In other words, the air meanders while passing between the louvers 24C and swinging in the tube extension direction DRt between the fin body 24. By making the air flow in a meandering manner in this way, the performance of the heat exchange between the refrigerant and the air can be improved. The plurality of louvers 24C may not be divided into a plurality of louver groups.

[0058] The main body intermediate portion 24B of the fin main body portion 24 includes the above-mentioned multiple louvers 24C, but the portion other than the louvers 24C is formed in a flat plate shape. Specifically, the main body intermediate portion 24B has multiple flat portions 24G formed along the air passing direction AF. The multiple flat portions 24G are arranged in line with the louvers 24C in the air passing direction AF. For example, the multiple flat portions 24G are arranged at an end on one side of the air passing direction AF of the main body intermediate portion 24B, an end on the other side of the air passing direction AF of the main body intermediate portion 24B, and the middle portion. The flat portions 24G of the middle portion of the main body intermediate portion 24B in the air passing direction AF are provided between the multiple louvers 24C of the main body intermediate portion 24B.

[0059] As shown in Fig. 3, the fin 20 is disposed across the first arrangement group 10A and the second arrangement group 10B of the tubes 10. The outer surface 21 of the fin 20 has a first region 21A and a second region 21B that is more hydrophilic than the first region 21A. Note that the wavy line in Fig. 3 indicates the boundary between the first region 21A and the second region 21B.

[0060] Specifically, the outer surface 21 of the fin 20 has a first region 21A and a second region 21B in a first fin body region 21C located between adjacent tubes 10 constituting the first array group 10A of the outer surface 21, i.e., between the tubes 10. Similarly, the outer surface 21 of the fin 20 has a first region 21A and a second region 21B in a second fin body region 21D located between adjacent tubes 10 constituting the second array group 10B of the outer surface 21, i.e., between the tubes 10.

[0061] The second region 21B is disposed adjacent to a portion of region 12A of the joint 12 between the tube 10 and the fin 20. Each of the fin main body regions 21C, 21D is formed by the region of the main body intermediate portion 24B and the curved portion 24A of the outer surface 21 of the fin 20. Therefore, the second region 21B is formed by the portion of the outer surface 21 corresponding to the main body intermediate portion 24B and the curved portion 24A of the fin 20.

[0062] The joint 12 is a portion where a part of the tube wall surface 11 of the tube 10 and the bent portion 23 of the fin 20 are joined by brazing. That is, the region of the joint 12 is a region where a part of the tube wall surface 11 of the tube 10 and the bent portion 23 of the fin 20 overlap. The shape of the overlapping region is, for example, a rectangular shape. The part of the joint 12 exposed to the outside is a linear range along the air passing direction AF. Therefore, it can be said that the region 12A of the part of the joint 12 is a part of the linear range of the joint 12 exposed to the outside. That is, the second region 21B is disposed adjacent to a part of the linear range of the joint 12 exposed to the outside.

[0063] Furthermore, adjacent arrangement means, for example, that the second region 21B is connected to a part of a linear range of the joint 12 that is exposed to the outside. In other words, the second region 21B is connected to the joint 12. Alternatively, the adjacent arrangement does not necessarily mean that the second region 21B is connected to the joint 12, and the second region 21B and a part of the joint 12, a region 12A, may be arranged very close to each other.

[0064] In this embodiment, the second region 21B is adjacent to both the region 12A of the joint 12 on one side of the adjacent tubes 10 and the region 12A of the joint 12 on the other side. That is, the second region 21B is set from end to end in the tube arrangement direction DRst. Similarly, the first region 21A is adjacent to both the region 12A of the joint 12 on one side of the adjacent tubes 10 and the region 12A of the joint 12 on the other side. In this case, the first region 21A is formed by a part of the outer surface 21 corresponding to the main body intermediate portion 24B and the curved portion 24A of the fin 20, similar to the second region 21B.

[0065] In the first fin main body region 21C, the first region 21A and the second region 21B are arranged in the order of the first region 21A, the second region 21B, and the first region 21A along the air passing direction AF. Similarly, in the second fin main body region 21D, the first region 21A and the second region 21B are arranged in the order of the first region 21A, the second region 21B, and the first region 21A along the air passing direction AF. That is, in each of the fin main body regions 21C and 21D, one second region 21B is arranged sandwiched between two first regions 21A.

[0066] 4 and 5, a plurality of grooves 22 are formed in the second region 21B of the first fin body region 21C to improve the hydrophilicity of the outer surface 21 of the fin 20. Similarly, grooves 22 are formed in the second region 21B of the second fin body region 21D.

[0067] In Fig. 4, in order to clearly show groove portion 22, dotted hatching is applied to groove portion 22. This is the same in the figures described below. Also, the wavy line in Fig. 4 indicates the boundary between curved portion 24A and main body intermediate portion 24B.

[0068] The grooves 22 are unevenly shaped formed on the outer surface 21 of the fin 20. As a result, in each of the fin body regions 21C, 21D, the second region 21B is more hydrophilic than the first region 21A. That is, the grooves 22 are not formed over the entire outer surface 21 of the fin 20, but are formed only in a portion of each of the fin body regions 21C, 21D.

[0069] Here, the groove portion 22 being formed to increase the hydrophilicity of the outer surface 21 of the fin 20 means that the groove portion 22 is formed to increase the hydrophilicity of the outer surface 21 of the fin 20 compared to when the outer surface 21 of the fin 20 is a smooth surface without any irregularities.

[0070] The grooves 22 are formed with a starting point 12B at a position in a partial region 12A of the joint 12, along a direction away from the joint 12 in the planar direction of the outer surface 21 of the fin 20. In this embodiment, the grooves 22 are formed along the tube arrangement direction DRst. That is, the grooves 22 extend in a direction perpendicular to the tube wall surface 11.

[0071] Since it is sufficient that the groove portion 22 extends from a starting point 12B at a position within a partial region 12A of the joint portion 12, the groove portion 22 may or may not be formed in the curved portion 24A. In other words, the groove portion 22 may or may not be connected to the tube wall surface 11. In this embodiment, the groove portion 22 is formed in the curved portion 24A and is connected to the tube wall surface 11.

[0072] In addition, when only the flat portion 24G is located in the second region 21B, the groove portion 22 is formed only in the flat portion 24G. Alternatively, when the flat portion 24G and the louver 24C are located in the second region 21B, the groove portion 22 is formed in the flat portion 24G and the louver main body portion 24D. Of course, even if both the flat portion 24G and the louver main body portion 24D are located in the second region 21B, the groove portion 22 may be formed only in the flat portion 24G, or the groove portion 22 may be formed only in the louver main body portion 24D.

[0073] The width over which the multiple grooves 22 are arranged in the air passing direction AF is set to, for example, 30% or less of the overall width of the fin 20. In other words, the width of the second region 21B in the air passing direction AF is 30% or less of the overall width of the fin 20.

[0074] The multiple grooves 22 are arranged side by side at intervals at a predetermined groove pitch. Each of the multiple grooves 22 extends in one direction along the outer surface 21 of the fin 20 and is arranged in parallel. Each of the multiple grooves 22 is formed so as to be recessed into the outer surface 21 of the fin 20 by a predetermined groove depth Hg.

[0075] 5 shows the thickness direction DRf of the fin 20, but the thickness direction DRf is the thickness direction of each portion of the fin 20. That is, the thickness direction DRf of the fin 20 is the thickness direction of the fin main body 24 at the fin main body 24, the thickness direction of the bent portion 23 at the bent portion 23, and the thickness direction of the louver 24C at the louver 24C.

[0076] Moreover, the plurality of grooves 22 in the outer surface 21 of the fin 20 are formed, for example, before the fin 20 is formed into a corrugated shape. Therefore, the plurality of grooves 22 in the outer surface 21 of the fin 20 include grooves that extend continuously across the plurality of portions 12, 24A, 24B, 24D, 24E, 24F, and 24G that constitute the fin 20.

[0077] Here, the groove depth of the groove portion 22 is, for example, 10 μm or more at any point on the outer surface 21 of the fin 20. The groove depth is the depth of the recessed portion based on the outer surface 21 of the fin 20. This makes it possible to sufficiently increase the hydrophilicity of the outer surface 21 of the fin 20. When the hydrophilicity of the outer surface 21 of the fin 20 is increased, the drainage property of the fin 20 is improved accordingly, and it is possible to suppress the accumulation of condensed water on the outer surface 21 of the fin 20. Note that the greater the groove depth Hg, the higher the hydrophilicity of the outer surface 21 of the fin 20.

[0078] The groove pitch of the multiple groove portions 22 is, for example, 0.2 mm or less. The groove pitch is, for example, the distance between the width centers of adjacent groove portions 22 in the air passing direction AF. The narrower the groove pitch, the higher the hydrophilicity of the outer surface 21 of the fin 20. In other words, the greater the number of the multiple groove portions 22, the higher the hydrophilicity of the outer surface 21 of the fin 20.

[0079] The groove width of the multiple grooves 22 is, for example, 10 μm or more. The groove width is the width of the recessed portion in the air passing direction AF of the grooves 22. The narrower the groove width, the higher the hydrophilicity of the outer surface 21 of the fin 20.

[0080] In this embodiment, the second region 21B is disposed in the center of the air passing direction AF between the tubes 10. That is, the groove 22 is located in the center of the air passing direction AF between the tubes 10. The groove 22 is a structure that makes the fin 20 thin, but since the second region 21B is located in the center of the air passing direction AF, the end of the fin 20 can support the center. Therefore, the strength of the fin 20 can be ensured. In addition, there is an advantage that the groove 22 is easier to form in the center than when the groove 22 is formed at the end of the fin 20 in the air passing direction AF. Therefore, the productivity of the fin 20 can be improved.

[0081] The plate-like member constituting the fin 20 has both sides, one side and the other side. The fin 20 is folded in a wave shape. Therefore, the outer surface 21 of the fin 20 is repeatedly arranged in the order of one side, the other side, the other side, and one side of the plate-like member in the tube extension direction DRt. The first region 21A and the second region 21B may be set on at least one of the one side and the other side of the plate-like member. In this embodiment, the first region 21A and the second region 21B are set on both the one side and the other side of the plate-like member. In addition, the position of the groove portion 22 on one side of the plate-like member and the position of the groove portion 22 on the other side may overlap or may be shifted in the plate thickness direction DRf of the fin 20. From the viewpoint of ensuring the strength of the fin 20, it is desirable that the position of the groove portion 22 on one side of the plate-like member and the position of the groove portion 22 on the other side are shifted in the plate thickness direction DRf of the fin 20.

[0082] Next, a description will be given of evaporation of condensed water generated in the heat exchanger 1. First, the amount of condensed water generated changes depending on the load condition of the heat exchanger 1. For example, when the refrigeration cycle is under high load, a large amount of condensed water is generated.

[0083] Fig. 6 is a diagram for explaining the high drainage mode when a large amount of condensed water Wc is generated. The upper part of Fig. 6 shows the amount of condensed water Wc in the air passing direction AF, the middle part of Fig. 6 shows the drainage mode when the groove portion 22 is a partial groove formed in a part of the outer surface 21 of the fin 20, and the lower part of Fig. 6 shows the drainage mode when the groove portion 22 is not formed in the outer surface 21 of the fin 20 and there is no groove.

[0084] The middle and lower views of Fig. 6 correspond to the view in the direction of arrow III in Fig. 2, and the arrows indicate the movement direction of the condensed water Wc. The condensed water Wc that accumulates in the curved portion 24A of the fin 20 is represented by a thick line, and this is also the case in the following Figs. 7, 9, and 10.

[0085] When a large amount of condensed water Wc is generated, much of the condensed water Wc is generated at the curved portions 24A of the fins 20 and on the outer surfaces 21 of the fins 20. As shown in the upper part of Fig. 6, when air flows between the tubes 10 from the first arrangement group 10A side in the air passing direction AF, the amount of condensed water peaks between the tubes 10 constituting the first arrangement group 10A. It can also be said that the second regions 21B of the outer surfaces 21 of the fins 20 where the grooves 22 are formed are positioned to match the position of the peak amount of condensed water.

[0086] The amount of condensed water decreases toward the downstream side in the air passing direction AF, i.e., toward the spaces between the tubes 10 of the second array group 10B. No peak in the amount of condensed water occurs between the tubes 10 constituting the second array group 10B.

[0087] When the refrigeration cycle is under high load, a large amount of condensed water Wc is generated, and the droplets of the condensed water Wc tend to join together. As shown in the middle of FIG. 6, the second region 21B and the grooves 22 are provided at the center of the air passage direction AF where the most condensed water Wc is generated, so that the condensed water Wc can be drawn into the second region 21B from the first region 21A located on both sides of the second region 21B where the grooves 22 are formed. The condensed water Wc in the second region 21B can be transported to the tube wall surface 11 along the grooves 22. This allows the condensed water Wc to be drained along the tube 10.

[0088] Since the amount of the condensed water Wc is large, the droplets of the condensed water Wc tend to join together even in the first region 21A. Therefore, the condensed water Wc flows from the first region 21A to the tube wall surface 11 and is drained along the tube 10.

[0089] In contrast to the above drainage mode, when there are no grooves, droplets of the condensed water Wc join together on the outer surface 21 of the fin 20, flow to the tube wall surface 11, and are drained along the tube 10. Since no grooves 22 are formed on the outer surface 21 of the fin 20, the ability to draw the condensed water Wc to the center position in the air passing direction AF and the ability to transport the condensed water Wc to the tube wall surface 11 are lower than when grooves 22 are formed on the outer surface 21 of the fin 20. In other words, the condensed water Wc is drained, but the drainage capacity is lower than when grooves 22 are provided.

[0090] When the refrigeration cycle is under low load, the amount of condensed water Wc generated is less than when the refrigeration cycle is under high load. In this case, the droplets of the condensed water Wc are less likely to join together. In addition, the condensed water Wc evaporates. Of course, the condensed water Wc is easily drawn into the grooves 22 provided in the second region 21B of the outer surface 21 of the fin 20. If the amount of condensed water Wc in the second region 21B increases, it is appropriately drained from the tube wall surface 11 to the tube 10 via the grooves 22.

[0091] Next, cases where the condensed water Wc evaporates all at once when switching between inside and outside air at low load of the refrigeration cycle, when crossing the dew point when the compressor is turned off, during fuel consumption control, etc. will be described with reference to Figures 7 and 8. Each diagram in Figure 7 corresponds to the view indicated by the arrow III in Figure 2. In Figure 7, the condensed water Wc that accumulates in the curved portion 24A is represented by a thick line, and the range of the condensed water Wc on the outer surface 21 of the fin 20 is represented by hatching.

[0092] The left side of FIG. 7 shows the case where the grooves 22 are formed on the entire outer surface 21 of the fin 20, the center of FIG. 7 shows the case where the grooves 22 are partially formed, and the right side of FIG. 7 shows the case where the grooves are not formed. The left side of FIG. 7 shows the case where the grooves 22 are formed on the entire outer surface 21 of the fin 20, and the right side of FIG. 7 shows the case where the grooves are not formed on the entire outer surface 21 of the fin 20. The right side of FIG. 7 shows the case where the grooves 22 are not formed on the entire outer surface 21 of the fin 20, and the right side of FIG. 7 shows the case where the grooves are not formed on the entire outer surface 21 of the fin 20. The left side of FIG. 7 shows the case where the grooves ... formed on the entire outer surface 21 of the fin 20. The right side of FIG. 7 shows the case where the grooves are formed on the entire outer surface 21 of the fin 20. The left side of FIG. 7 shows the case where the grooves are formed on the entire outer surface 21 of the fin 20. The right side of FIG. 7 shows the case where the grooves are formed on the entire outer surface 21 of the fin 20. The left side of FIG. 7 shows the case where the grooves are formed on the entire outer

[0093] First, as shown on the right side of FIG. 7, in the case where there is no groove, the heat exchanger 1 gradually exchanges heat with warm air from the first array group 10A side, which is the windward side of the air passing direction AF. As a result, the outer surface 21 of the fin 20 gradually dries from the windward side to the leeward side of the air passing direction AF. However, the condensed water Wc that accumulates in the fillet portion of the tube 10 and the fin 20, i.e., the curved portion 24A of the fin 20, accumulates in a small, extremely small area. Therefore, the condensed water Wc in the curved portion 24A dries more slowly after the entire outer surface 21 of the fin 20 dries. In FIG. 7, the condensed water Wc on the outer surface 21 of the fin 20 is represented by hatching, and the condensed water Wc that accumulates in the curved portion 24A is represented by a thick line.

[0094] Therefore, as shown in Fig. 8, when there are no grooves, the evaporation rate of the condensed water Wc is very slow, and it takes a long time for all of the condensed water Wc to finish evaporating.

[0095] Next, as shown in the left side of Fig. 7, in the case of full grooves, the condensed water Wc accumulated in the grooves 22 exchanges heat with warm air. As a result, while drying the outer surface 21 of the fin 20, the condensed water Wc accumulated in the curved portion 24A of the fin 20 is drawn into the outer surface 21 of the fin 20 by the capillary phenomenon of the grooves 22. Therefore, before the entire outer surface 21 of the fin 20 finishes drying, the curved portion 24A of the fin 20 also starts drying. In other words, the high drainage property of the grooves 22 prevents the condensed water Wc from moving to the tube wall surface 11, and promotes the evaporation of the condensed water Wc on the outer surface 21 of the fin 20.

[0096] Therefore, as shown in FIG. 8, in the case of full groove, the evaporation rate of the condensed water Wc increases rapidly in a short time and exceeds the threshold value that is the criterion for odor generation. As a result, the odorous components dissolved in the condensed water Wc are released all at once. Also, as shown in FIG. 9, the odorous components are released all at once from the entire area between the tubes 10 on the outer surface 21 of the fin 20. This may cause the user to smell an odor. The odorous components are, for example, odorous components in the vehicle cabin, components contained in adhesives as vehicle parts, and components contained in the user's sweat.

[0097] Next, as shown in the center of Figure 7, in the case of partial grooves, as in the case of full grooves, while drying the outer surface 21 of the fin 20, the groove portion 22 of the second region 21B draws the condensed water Wc accumulated in the curved portion 24A of the fin 20 into the second region 21B by capillary action of the groove portion 22.

[0098] However, the area where the condensed water Wc is drawn into the grooves 22 is only the second region 21B between the tubes on the outer surface 21 of the fin 20. In other words, the area where the grooves 22 are formed on the outer surface 21 of the fin 20 is divided into the second region 21B of the first arrangement group 10A and the second region 21B of the second arrangement group 10B. Therefore, the area of ​​the area where the condensed water Wc is drawn into the grooves 22 is smaller than when the grooves 22 are formed on the entire outer surface 21 of the fin 20. Accordingly, the amount of condensed water Wc drawn from the curved portion 24A of the fin 20 to the grooves 22 of the second region 21B of the fin 20 is also reduced, so that the evaporation of the condensed water Wc on the outer surface 21 of the fin 20 is suppressed. As a result, the release of odorous components during the evaporation of the condensed water Wc is suppressed. Therefore, as shown in FIG. 10, the odorous components can be reduced from the gaps between the tubes 10 on the outer surface 21 of the fin 20. It is also possible to prevent the user from sensing an odor.

[0099] In addition, since the second region 21B where the grooves 22 are formed between the tubes 10 is located at the center of the air passing direction AF, the relative humidity of the air becomes high downstream of the second region 21B. This also slows down the evaporation rate of the condensed water Wc.

[0100] Therefore, as shown in Figure 8, the evaporation rate of the condensed water Wc can be ensured to a level that does not exceed the threshold value that is the criterion for odor generation, and the time until all the condensed water Wc has evaporated can be extended, compared to the case where the entire groove is filled.

[0101] 7, the difference in time lapse between the full groove, partial groove, and no groove is merely shown as a schematic diagram, and is therefore unrelated to the actual time difference between the full groove, partial groove, and no groove.

[0102] As described above, in this embodiment, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B that has higher hydrophilicity than the first region 21A. Also, the second region 21B has a groove 22 formed therein that improves the hydrophilicity of the outer surface 21 of the fin 20. Furthermore, the second region 21B is disposed adjacent to a part of the region 12A of the joint 12 between the tube 10 and the fin 20.

[0103] According to this, the area into which the condensed water Wc is drawn by the groove portion 22 is only the second region 21B. Therefore, the area into which the condensed water Wc is drawn can be made smaller than when the condensed water Wc is drawn into the entirety of each of the fin main body regions 21C, 21D by the groove portion 22.

[0104] Therefore, in a situation where the generation of the condensed water Wc is small and the condensed water Wc evaporates all at once, the evaporation rate of the condensed water Wc in each of the fin body regions 21C, 21D can be slowed down. This makes it possible to prevent the odorous components contained in the condensed water Wc from being released all at once. In addition, in a situation where a large amount of condensed water Wc is generated, the condensed water Wc can be appropriately drained into the tube 10 via the groove portion 22 of the fin 20. Therefore, it is possible to suppress odor while ensuring the drainage properties of the fin 20.

[0105] Second embodiment In this embodiment, differences from the first embodiment will be mainly described. In this embodiment, the shape of the grooves 22 is different from that of the first embodiment. Figures 11 to 14 show the groove patterns of the grooves 22 in the first arrangement group 10A.

[0106] For example, as shown in Fig. 11, the grooves 22 are formed along the tube arrangement direction DRst and also along the air passing direction AF. That is, the grooves 22 extend in two directions. The grooves 22 along the tube arrangement direction DRst and the grooves 22 along the air passing direction AF intersect at right angles. Thus, the grooves 22 are formed in a lattice pattern. This allows the grooves 22 to draw more condensed water Wc into the second region 21B.

[0107] The grooves 22 in two directions are not limited to intersecting at a right angle, and may intersect at an angle other than a right angle. Also, the grooves 22 are not limited to being formed in two directions, and may be formed in three or more directions.

[0108] Alternatively, as shown in FIGS. 12 and 13, the grooves 22 may be formed along a direction inclined with respect to the tube arrangement direction DRst.

[0109] 14, the grooves 22 may be formed in a staggered pattern along the tube arrangement direction DRst. The staggered pattern means that the grooves 22 are formed intermittently along the tube arrangement direction DRst and are arranged alternately along the air passing direction AF. By ensuring two or more levels of plate thickness, the rigidity (strength) of the fins 20 can be ensured.

[0110] For example, the grooves 22 may be formed on both sides of the plate-like member, the grooves 22 may be arranged in a staggered pattern on both the front and back surfaces of the plate-like member, the second regions 21B may be located approximately at the center of the air passage direction AF between the tubes 10, and the second regions 21B may be arranged evenly on the left and right between the tubes 10 of each array group 10A, 10B. The staggered grooves 22 may overlap or be shifted in the plate thickness direction DRf of the fin 20. In addition, when the second regions 21B are located at the center of the air passage direction AF between the tubes 10, the first region 21A on the upstream side and the first region 21A on the downstream side of the air passage direction AF may be set to have the same area.

[0111] Here, left and right represent the first array group 10A on the upstream side and the second array group 10B on the downstream side in the air passing direction AF. For example, in FIG. 3, the first array group 10A is depicted on the left side and the second array group 10B is depicted on the right side on the paper. Furthermore, "even" means that the area of ​​the region (second region 21B) in which the groove portion 22 is formed is the same on the left and right, and the position in the air passing direction AF between the tubes 10 is the same on the left and right. Therefore, "evenly arranged on the left and right" means that the second regions 21B of each array group 10A, 10B have the same area and are located in the same center between the tubes 10 in the air passing direction AF.

[0112] 12 to 14, the grooves 22 provided in the outer surface 21 of the fin 20 are shown to be larger than their actual size for the sake of explanation. Furthermore, the direction in which each of the grooves 22 extends, i.e., the one direction along the outer surface 21 of the fin 20, is not particularly limited.

[0113] 11 to 14 show the grooves 22 in the first arrangement group 10A, but the shape of the grooves 22 in the second arrangement group 10B is the same as that of the first arrangement group 10A. Of course, the shape of the grooves 22 in the first arrangement group 10A and the shape of the grooves 22 in the second arrangement group 10B may be different. Alternatively, it is possible to provide the grooves 22 in the first arrangement group 10A and not provide the grooves 22 in the second arrangement group 10B.

[0114] As described above, when forming groove portion 22 along a direction away from joint 12 with starting point 12B being a position within a portion of region 12A of joint 12, groove portion 22 is not limited to a single straight line and can be changed to other shapes.

[0115] Third embodiment In this embodiment, differences from the first and second embodiments will be mainly described. In this embodiment, grooves 22 for improving the hydrophilicity of the outer surface 21 of the fin 20 are also formed in the first region 21A. However, the grooves 22 are formed in the first region 21A so that the hydrophilicity of the second region 21B is higher than that of the first region 21A.

[0116] 15, the depth of the grooves 22 formed in the second region 21B is deeper than the depth of the grooves 22 formed in the first region 21A. The depth of the grooves 22 formed in the first region 21A is, for example, 10 μm or more, and the depth of the grooves 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these depths are merely examples, and other depths may be set.

[0117] 16, the groove width of the groove portion 22 formed in the second region 21B is narrower than the groove width of the groove portion 22 formed in the first region 21A. The groove width of the groove portion 22 formed in the first region 21A is, for example, 10 μm or more, and the groove width of the groove portion 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these groove widths are merely examples, and other groove widths may be set.

[0118] The pitch of the grooves 22 formed in the second region 21B may be made smaller than the pitch of the grooves 22 formed in the first region 21A, so that the grooves 22 in the second region 21B are densely arranged and the grooves 22 in the first region 21A are sparsely arranged. Alternatively, the depth or width of the grooves 22 may be adjusted to make the groove pitch of the grooves 22 constant.

[0119] 17, the number of grooves 22 formed in the second region 21B is greater than the number of grooves 22 formed in the first region 21A. The number of grooves is compared, for example, in terms of the number per a certain area.

[0120] For example, the number of grooves 22 formed in the second region 21B is two to ten times the number of grooves 22 formed in the first region 21A. That is, by making the pitch of the grooves 22 formed in the second region 21B smaller than the pitch of the grooves 22 formed in the first region 21A, the grooves 22 in the second region 21B are densely arranged, and the grooves 22 in the first region 21A are sparsely arranged. The number of grooves 22 is just an example, and may be set to another number.

[0121] The groove depth, groove width, and number of the grooves 22 in the first arrangement group 10A may be the same as or different from the groove depth, groove width, and number of the grooves 22 in the second arrangement group 10B. The groove depth, groove width, and number of the grooves 22 in a certain area of ​​the second region 21B may not be uniform, and may be different within the second region 21B. For example, the groove depth of the grooves 22 in the second region 21B may become shallower in stages toward the first region 21A. Similarly, the groove depth, groove width, and number of the grooves 22 in a certain area of ​​the first region 21A may not be uniform.

[0122] As described above, in order to cause a difference in hydrophilicity between the first region 21A and the second region 21B, the depth, groove width, and number of grooves 22 can be adjusted. Of course, the depth, groove width, and number shown in Figures 15 to 17 may be combined. Furthermore, this can also be applied to the grooves 22 shown in Figures 11 to 14 of the second embodiment.

[0123] (Other embodiments) The configuration of the heat exchanger 1 shown in each of the above embodiments is merely an example, and the present invention is not limited to the above-described configuration, and other configurations that can realize the present invention may be used. For example, the above-described embodiments may be appropriately combined, and the above-described embodiments may be modified in various ways.

[0124] (1) In each of the above-described embodiments, the heat exchanger 1 is applied to an evaporator, but is not limited to this. For example, the heat exchanger 1 can be applied to other heat exchangers that generate condensed water, such as a cooler core.

[0125] (2) Although the heat exchanger 1 has a configuration in which the ends of the multiple tubes 10 are brazed to the first tank portion 30 and the second tank portion 40 and are stacked, the present invention is not limited to this configuration.

[0126] The heat exchanger 1 can be configured in various ways as long as it has a core portion formed by stacking a plurality of tubes and a pair of tank portions disposed at the ends of the tubes. For example, it is possible to configure a heat exchanger having a pair of tank portions and a plurality of tubes by stacking a pair of plate materials, which are formed by joining a pair of plate materials having a recess of a predetermined shape facing each other to form a tube.

[0127] (3) The second region 21B needs to be adjacent to at least one of a portion of region 12A of the joint 12 on one side of adjacent tubes 10 and a portion of region 12A of the joint 12 on the other side, but does not have to be adjacent to both.

[0128] (4) The shapes of the first region 21A and the second region 21B as viewed from the arrow III are not limited to a rectangle, and may be other shapes such as a trapezoid. The first region 21A and the second region 21B are not limited to a rectangle or other shape, and may be any shape including a curve. In addition, the boundary between the first region 21A and the second region 21B is not limited to a straight line, and may be a curve.

[0129] (5) Between adjacent tubes 10 on the outer surface 21 of the fin 20, the second region 21B does not have to be sandwiched between two first regions 21A. For example, between adjacent tubes 10 on the outer surface 21 of the fin 20, one first region 21A and one second region 21B may be arranged. Alternatively, the first region 21A and the second region 21B may be arranged alternately in the air passing direction AF. In this case, the number of first regions 21A and the number of second regions 21B may be the same or different. For example, two first regions 21A and two second regions 21B may be arranged alternately, or the second region 21B may be arranged between three first regions 21A.

[0130] (6) The grooves 22 do not have to be laid out in a straight line. The grooves 22 may be laid out in a curved line, for example. Alternatively, the grooves 22 may be laid out to include straight and curved lines.

[0131] (7) The tube 10 does not have to be a flat tube having a flat cross-sectional shape, and may be a tube of another shape. For example, the tube 10 may be cylindrical, and the tube wall surface 11 may be curved. In this case, the groove portion 22 is formed, for example, so as to be inclined with respect to the tangent line of the tube wall surface 11 with a partial region 12A of the joint portion 12 as a starting point 12B. Alternatively, the groove portion 22 may be formed so as to be inclined with respect to the normal line of the tube 10 with a partial region 12A of the joint portion 12 as a starting point 12B.

[0132] (8) The areas of the outer surface 21 of the fin 20 where the grooves 22 are formed are not limited to the curved portions 24A, the flat portions 24G, and the louver main body portions 24D. The grooves 22 may be formed, for example, in the louver one end portion 24E and the louver other end portion 24F.

[0133] (9) The outer surfaces 21 of the fins 20 may be subjected to a surface treatment to improve hydrophilicity. For example, the entire fins 20 may be coated with a hydrophilic resin having high water resistance, such as polyvinyl alcohol.

[0134] (10) The fins 20 do not necessarily have to have the louvers 24C formed thereon.

[0135] The technical features of the heat exchanger disclosed in this specification are as follows: (Item 1) A tube (10) through which a first fluid flows; a fin (20) formed by bending a plate-like member and promoting heat exchange between the first fluid and a second fluid flowing outside the tube; Including, The outer surface (21) of the fin has a first region (21A) and a second region (21B) that is more hydrophilic than the first region, A groove portion (22) that improves the hydrophilicity of the outer surface is formed in the second region, A heat exchanger, wherein the second region is disposed adjacent to a partial region (12A) of a joint (12) between the tube and the fin. (Item 2) The tubes are formed to extend in a tube stretching direction (DRt) and are arranged in a tube arrangement direction (DRst) intersecting the tube stretching direction to form an array group (10A, 10B); the fins are disposed between adjacent ones of the tubes constituting the array group, 2. The heat exchanger according to claim 1, wherein the first region and the second region are arranged in the order of the first region, the second region, and the first region along a second fluid flow direction that intersects the tube extension direction and the tube arrangement direction in a fin body region (21C, 21D) located between adjacent tubes on the outer surface of the fin. (Item 3) The array groups include a first array group (10A) and a second array group (10B) arranged in the second fluid flow direction, The fins are arranged across the first array group and the second array group, The first region and the second region are In a first fin body region (21C) located between adjacent tubes constituting the first arrangement group on the outer surface of the fin, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction, 3. The heat exchanger according to item 2, wherein in a second fin body region (21D) located between adjacent tubes that constitute the second arrangement group on the outer surface of the fin, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction. (Item 4) 4. The heat exchanger according to any one of items 1 to 3, wherein the groove portion is formed along a direction away from the joint portion, starting from a position within the partial region of the joint portion (12B). (Item 5) the first region is formed with the groove portion that improves the hydrophilicity of the outer surface of the fin; 5. The heat exchanger according to any one of items 1 to 4, wherein a depth of the groove formed in the second region is deeper than a depth of the groove formed in the first region. (Item 6) the first region is formed with the groove portion that improves the hydrophilicity of the outer surface of the fin; 6. The heat exchanger according to any one of items 1 to 5, wherein a groove width of the groove portion formed in the second region is narrower than a groove width of the groove portion formed in the first region (21A). (Item 7) the first region is formed with the groove portion that improves the hydrophilicity of the outer surface of the fin; 7. The heat exchanger according to any one of items 1 to 6, wherein the number of the grooves formed in the second region is greater than the number of the grooves formed in the first region. [Explanation of symbols]

[0136] 1 heat exchanger 10 Tubes 12 Joint 12A Some Areas 20. Finn 21 External surface 21A 1st area 21B 2nd area 22 Groove

Claims

1. a tube (10) through which a first fluid flows; a fin (20) formed by bending a plate-like member and promoting heat exchange between the first fluid and a second fluid flowing outside the tube; Including, The outer surface (21) of the fin has a first region (21A) and a second region (21B) that is more hydrophilic than the first region, The second region has a groove (22) formed therein that improves the hydrophilicity of the outer surface, The second region is disposed adjacent to a partial region (12A) of the joint (12) between the tube and the fin, The tubes are formed to extend in a tube stretching direction (DRt), and form an array group (10A, 10B) in which a plurality of the tubes are arranged in a tube array direction (DRst) intersecting the tube stretching direction, the fins are disposed between adjacent ones of the tubes that make up the array group, the first region and the second region are arranged in this order along a second fluid flow direction intersecting the tube extension direction and the tube arrangement direction in a fin body region (21C, 21D) located between adjacent tubes on the outer surface of the fin, The array groups include a first array group (10A) and a second array group (10B) arranged in the second fluid flow direction, the fins are arranged across the first array group and the second array group, The first region and the second region are In a first fin body region (21C) located between adjacent tubes constituting the first arrangement group on the outer surface of the fin, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction, and a second fin body region (21D) located between adjacent tubes constituting the second arrangement group on the outer surface of the fin, the first region, the second region, and the first region being arranged in this order along the second fluid flow direction.

2. The heat exchanger according to claim 1, wherein the groove portion is formed along a direction away from the joint portion, the groove portion starting from a position within the partial region of the joint portion.

3. the groove portion that improves the hydrophilicity of the outer surface of the fin is formed in the first region; The heat exchanger according to claim 1 , wherein the depth of the grooves formed in the second region is greater than the depth of the grooves formed in the first region.

4. the groove portion that improves the hydrophilicity of the outer surface of the fin is formed in the first region; The heat exchanger according to claim 1 , wherein a groove width of the grooves formed in the second region is narrower than a groove width of the grooves formed in the first region.

5. the groove portion that improves the hydrophilicity of the outer surface of the fin is formed in the first region; The heat exchanger according to claim 1 , wherein the number of the grooves formed in the second region is greater than the number of the grooves formed in the first region.

Images