Heat exchanger

Abstract

A heat exchanger includes a tube through which first fluid flows, and a fin formed by bending a plate-shaped member and configured to promote heat exchange between second fluid flowing outside the tube and the first fluid. The outer surface of the fin has a first region and a second region having higher hydrophilicity than the first region. The second region has a groove for improving hydrophilicity of the outer surface. The second region is provided adjacent to a partial region of the joint portion of the tube and the fin.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application is a continuation application of International Patent Application No. PCT / JP2024 / 029386 filed on Aug. 20, 2024, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2023-146860 filed on Sep. 11, 2023. The entire disclosures of all of the above applications are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to a heat exchanger.BACKGROUND

[0003] Conventionally, a known heat exchanger includes a tube and a fin that promotes heat exchange between fluid flowing in the tube and fluid flowing outside the tube.SUMMARY

[0004] According to an aspect of the present disclosure, a heat exchanger comprises: a tube configured to cause first fluid to flow therethrough; and a fin formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid. An outer surface of the fin includes a first region and a second region, the second region having higher hydrophilicity than the first region. The second region has a groove configured to improve hydrophilicity of the outer surface. The second region is adjacent to a partial region of a joint portion, which is between the tube and the fin.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the accompanying drawings:

[0006] FIG. 1 is a perspective view of a heat exchanger according to a first embodiment;

[0007] FIG. 2 is an enlarged perspective view of part of a tube and a fin of the heat exchanger in FIG. 1;

[0008] FIG. 3 is a view taken along arrow III in FIG. 2;

[0009] FIG. 4 is an enlarged plan view schematically illustrating a groove by enlarging and illustrating part of a joint portion of a tube and a fin in a second region of an outer surface of the fin in the first embodiment;

[0010] FIG. 5 is a sectional view taken along line V-V in FIG. 4;

[0011] FIG. 6 is a diagram for describing a high drain mode in which a generated amount of condensed water is large, in which the upper part shows an amount of condensed water corresponding to a position in an air passage direction, the middle part shows a drain mode in a case where a groove is formed in part of an outer surface of a fin, and the lower part shows a drain mode in a case where no groove is formed in the outer surface of the fin;

[0012] FIG. 7 is a diagram for describing how condensed water generated in the heat exchanger evaporates in a case where the entire outer surface of the fin has the groove, in a case where the groove is provided in part of the outer surface of the fin, and in a case where no groove is provided in the outer surface of the fin;

[0013] FIG. 8 is a diagram illustrating the relationship between the evaporation rate of the condensed water and the time until the evaporation of the condensed water is completed in a case where the entire outer surface of the fin has the groove, in a case where the groove is provided in part of the outer surface of the fin, and in a case where no groove is provided in the outer surface of the fin;

[0014] FIG. 9 is a perspective view illustrating a state in which a large amount of odor component is released in a case where the entire outer surface of the fin has the groove;

[0015] FIG. 10 is a perspective view illustrating a state in which a small amount of odor component is released in a case where part of the outer surface of the fin has the groove;

[0016] FIG. 11 is a plan view schematically illustrating a groove formed in a second region in a second embodiment;

[0017] FIG. 12 is a plan view schematically illustrating a groove formed in a second region in the second embodiment;

[0018] FIG. 13 is a plan view schematically illustrating a groove formed in a second region in the second embodiment;

[0019] FIG. 14 is a diagram illustrating a groove formed in a second region in the second embodiment;

[0020] FIG. 15 is an enlarged cross-sectional view illustrating some grooves formed in a first region and a second region in a third embodiment;

[0021] FIG. 16 is an enlarged plan view illustrating some grooves formed in a first region and a second region in the third embodiment; and

[0022] FIG. 17 is an enlarged plan view illustrating some grooves formed in a first region and a second region in the third embodiment.DETAILED DESCRIPTION

[0023] Hereinafter, examples of the present disclosure will be described.

[0024] According to an example of the present disclosure, a heat exchanger includes a tube, though which a first fluid flows, and a fin that promotes heat exchange between a second fluid, which flows outside the tube, and the first fluid. In the heat exchanger, condensed water may be generated according to a load state of the heat exchanger, and the condensed water may be retained on the outer surface of the fin. Therefore, in order to improve the drainage property of the fin. For example, an assumable heat exchanger may have a groove in its entire surface of a fin.

[0025] For example, when a refrigeration cycle including the heat exchanger operates under a high load, a large amount of condensed water is generated in the heat exchanger. For this reason, the condensed water generated on the outer surface of the fin easily merges with each other by forming a water film on the entire surface, and may be easily drained to the tube through the groove.

[0026] On the other hand, the amount of condensed water generated in the heat exchanger is small during a low-load operation of the refrigeration cycle. Therefore, the condensed water flowing on the tube and the condensed water retained in the joint portion of the fin and the tube are drawn into the central portion of the fin due to the capillary phenomenon of the groove, and the condensed water remains on the outer surface of the fin. That is, the groove for improving the drainage property of the condensed water conversely deteriorates the drainage property during the low-load operation of the refrigeration cycle.

[0027] In the refrigeration cycle, particularly during the low-load operation, in a case where a compressor is turned ON and OFF, or in a case where the low pressure is increased for power saving, when the temperature of the fin rises and the condensed water remaining on the outer surface of the fin evaporates at once, odor component contained in the condensed water is released all at once. As a result, there is a possibility that an odor is generated.

[0028] According to an example of the present disclosure, a heat exchanger comprises: a tube configured to cause first fluid to flow therethrough; and a fin formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid.

[0029] An outer surface of the fin includes a first region and a second region, the second region having higher hydrophilicity than the first region.

[0030] The second region has a groove configured to improve hydrophilicity of the outer surface.

[0031] The second region is adjacent to a partial region of a joint portion, which is between the tube and the fin.

[0032] Accordingly, only the second region has high hydrophilicity in the region of the outer surface of the fin provided adjacent to the joint portion of the tube and the fin. Therefore, the area into which the condensed water is drawn can be made smaller than that in a case where the condensed water is drawn into the entire region provided adjacent to the joint portion by the groove.

[0033] Therefore, in a situation where the generation of the condensed water is small, the evaporation rate of the condensed water in the region of the outer surface of the fin provided adjacent to the joint portion of the tube and the fin can be decreased. Therefore, in a situation where the condensed water evaporates at once, it is possible to suppress the instant release of the odor component contained in the condensed water. In addition, in a situation where a large amount of condensed water is generated, the condensed water can be drained to the tube via the groove of the fin.

[0034] Therefore, in a situation where the condensed water evaporates at once, it is possible to suppress the odor while ensuring the drainage property of the fin.

[0035] Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment are denoted by the same reference numerals, and redundant description may be omitted. In a case where only part of the configuration is described in each embodiment, other embodiments precedingly described can be applied to the other parts of the configuration. It is possible to not only combine portions specifically indicating that combinations are possible in the respective embodiments, but also partially combine the embodiments even if it is not explicitly described unless there is a problem in the combination.First Embodiment

[0036] The heat exchanger according to the present embodiment is used, for example, as an evaporator constituting part of a refrigeration cycle that performs air conditioning in a vehicle interior of a vehicle. The refrigeration cycle includes, for example, a compressor, a condenser, an expansion valve, and an evaporator. The evaporator is provided inside an air conditioning case through which blown air to be blown into the vehicle interior flows.

[0037] Therefore, the evaporator exchanges heat between the low-pressure refrigerant as the first fluid in 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 causing the low-pressure refrigerant to absorb heat from the blown air. That is, the evaporator is a cooling heat exchanger for cooling air by latent heat of vaporization of the refrigerant.

[0038] Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 10. As illustrated in FIGS. 1 and 2, a heat exchanger 1 includes a plurality of tubes 10, a plurality of fins 20, a first tank 30, a second tank 40, an outer frame member 50, and a pipe connection member 60. These members are made of, for example, an aluminum alloy, and the members are joined to each other by brazing. An arrow DRg in FIG. 1 indicates an up and down direction DRg of the heat exchanger 1.

[0039] An outer surface 21 of the fin 20 has a plurality of the grooves 22 (see FIGS. 4 and 5) as described later. However, since the groove 22 is extremely fine as compared to the size of the fin 20, it is not illustrated in FIGS. 2 and 3. The same applies to other drawings, which will be described later, illustrating the fin 20 except for the enlarged view of the groove 22.

[0040] As illustrated in FIG. 3, the plurality of tubes 10 is provided at predetermined intervals in a tube array direction DRst. Air passing through the heat exchanger 1 flows between the plurality of tubes 10. That is, the air flows between the adjacent tubes 10 in the tube array direction DRst. Between the tubes 10, the air flows with one side of an air passage direction AF as the upstream side (windward) and the other side of the air passage direction AF as the downstream side (leeward). In other words, the air passage direction AF is a second fluid flow direction.

[0041] The air passing through the heat exchanger 1 flows between the tubes 10 and is cooled by the refrigerant to generate condensed water. That is, the air passing through the heat exchanger 1 is a gas that generates condensed water by heat exchange with the refrigerant.

[0042] The tube 10 is a flat tube having a flat cross-sectional shape with the tube array direction DRst as a short-side direction and the air passage direction AF as a longitudinal direction. The plurality of tubes 10 constitute a first array group 10A and a second array group 10B each of which has the plurality of tubes 10 provided in the tube array direction DRst intersecting a tube extending direction DRt. The tube extending direction DRt is a direction in which the tube 10 extends.

[0043] The first array group 10A and the second array group 10B are provided in the air passage direction AF. That is, the plurality of tubes 10 is provided in two rows on one side and the other side of the air passage direction AF. In the present embodiment, in the air passage direction AF, the first array group 10A is located upstream of the air flow, and the second array group 10B is located downstream of the air flow.

[0044] As illustrated in FIG. 1, each of the plurality of tubes 10 is formed so as to extend linearly along the tube extending direction DRt from one end to the other end. The refrigerant flows inside each tube 10. The tube extending direction DRt does not necessarily coincide with the up and down direction DRg. In the present embodiment, the tube extending direction DRt coincides with the up and down direction DRg. Each of the tubes 10 of the present embodiment extends in the up and down direction DRg, that is, in the vertical direction DRg.

[0045] The air passage direction AF, the tube array direction DRst, and the tube extending direction DRt intersect each other, and strictly, are directions orthogonal to each other.

[0046] The plurality of tubes 10 is inserted into the first tank 30 at the upper end, and inserted into the second tank 40 at the lower end. The first tank 30 and the second tank 40 distribute the refrigerant to the plurality of tubes 10 and collect the refrigerant flowing from the plurality of tubes 10.

[0047] Each of the tanks 30 and 40 is formed in a tubular shape using the same material as the tube 10. Each of the tanks 30 and 40 is formed in a shape extending in the tube array direction DRst. The term “tubular shape” includes not only a cylindrical shape but also a polygonal tubular shape such as a quadrangular tubular shape.

[0048] The inside of the first tank 30 has an internal space which the refrigerant of the refrigeration cycle flows into and out of. The internal space of the first tank 30 is divided into an upstream side and a downstream side in the air passage direction AF. That is, the first tank 30 includes a first leeward tank 31 located downstream in the air passage direction AF and a first windward tank 32 located upstream in the air passage direction AF.

[0049] The first windward tank 32 is connected to and communicates with one end of each of the plurality of windward tubes 10 upstream of the first tank 30 in the air passage direction AF. The first windward tank 32 functions as a collecting tank that collects the refrigerant passing through the plurality of windward tubes 10.

[0050] On the other hand, the first leeward tank 31 is connected to and communicates with one end of each of the plurality of leeward tubes 10 downstream of the first tank 30 in the air passage direction AF. The first leeward tank 31 functions as a distribution tank that distributes the refrigerant to the plurality of leeward tubes 10.

[0051] In the heat exchanger 1 according to the first embodiment, the second tank 40 is provided at the lower part of the heat exchanger 1 in the up and down direction DRg. The second tank 40 is joined to the lower end of each tube 10 by brazing.

[0052] The inside of the second tank 40 has an internal space which the refrigerant of the refrigeration cycle flows into and out of. The internal space of the second tank 40 is divided into the windward and the leeward. That is, the second tank 40 includes a second leeward tank 41 located downstream in the air passage direction AF and a second windward tank 42 located upstream in the air passage direction AF.

[0053] The second windward tank 42 is connected to and communicates with the other end of each of the plurality of windward tubes 10 upstream of the second tank 40 in the air passage direction AF. The second windward tank 42 functions as a distribution tank that distributes the refrigerant to the plurality of windward tubes 10.

[0054] On the other hand, the second leeward tank 41 is connected to and communicates with the other end of each of the plurality of leeward tubes 10 downstream of the second tank 40 in the air passage direction AF. The second leeward tank 41 functions as a collecting tank that collects the refrigerant having passed through the plurality of leeward tubes 10.

[0055] The second leeward tank 41 communicates with the second windward tank 42 inside the second tank 40. Therefore, the second tank 40 can supply the refrigerant collected in the second leeward tank 41 to the second windward tank 42 and distribute the refrigerant to the windward tubes 10 at the second windward tank 42.

[0056] Since air flows between the plurality of tubes 10, the gap formed between the tubes 10 is an air passage through which air flows. The fins 20 are provided at the air passage. In other words, the fin 20 is provided between the adjacent tubes 10 in the tube array direction DRst. Therefore, the fin 20 is an outer fin provided outside the tube 10.

[0057] The fin 20 promotes heat exchange between the refrigerant flowing inside the tube 10 and air flowing between the tubes 10. Specifically, the fin 20 increases the area for the heat transfer between the refrigerant flowing inside the tube 10 and the air flowing outside the tube 10 to increase the heat exchange efficiency between the refrigerant and the air.

[0058] In the tube array direction DRst, a pair of outer frame members 50 is provided further outside the portion where the plurality of tubes 10 and the plurality of fins 20 are alternately provided. The pipe connection member 60 is fixed to one of the pair of outer frame members 50.

[0059] The pipe connection member 60 is a refrigerant pipe connection member in the refrigeration cycle. The pipe connection member 60 is joined to a side face of the first tank 30 at one end in the tube array direction DRst by brazing.

[0060] The pipe connection member 60 has a refrigerant inflow port 61 to which a refrigerant is supplied and a refrigerant outflow port 62 for discharging the refrigerant. An outlet of the expansion valve in the refrigeration cycle is connected to the refrigerant inflow port 61 via a refrigerant pipe. A refrigerant inflow passage (not illustrated) is connected to the refrigerant inflow port 61. The refrigerant inflow passage is formed inside the pipe connection member 60 and connects the refrigerant inflow port 61 and the internal space of the first leeward tank 31.

[0061] On the other hand, a suction port of the compressor in the refrigeration cycle is connected to the refrigerant outflow port 62 via a refrigerant pipe. A refrigerant outflow passage (not illustrated) is connected to the refrigerant outflow port 62. The refrigerant outflow passage is formed inside the pipe connection member 60 and connects the refrigerant outflow port 62 and the internal space of the first windward tank 32.

[0062] The refrigerant flowing from the refrigerant inflow port 61 into the first tank 30 flows through the internal space of each of the tanks 30 and 40 and the plurality of tubes 10 in a predetermined path, and flows out from the refrigerant outflow port 62. At this time, the air flowing through the air passage provided with the fins 20 is cooled by latent heat of vaporization of the refrigerant flowing through the tanks 30 and 40 and the plurality of tubes 10.

[0063] The fin 20 is a component that promotes heat exchange between air flowing outside the tube 10 and the refrigerant. As illustrated in FIG. 2, the fin 20 is formed by bending a plate-shaped member. Specifically, the fin 20 is bent to form a continuous corrugated shape in the tube extending direction DRt. The fin 20 is, for example, a corrugated fin.

[0064] The fin 20 includes a plurality of bent portions 23 and a plurality of fin body portions 24. The plurality of bent portions 23 constitute corrugated top portions of the fin 20. Since the bent portion 23 constitutes the corrugated top portion of the fin 20, it is referred to as a fin TOP portion.

[0065] The bent portion 23 is joined to a tube wall face 11 which is a side face of the tube 10, the side face facing in the tube array direction DRst. That is, a surface of the surfaces on both sides of the bent portion 23 in the plate thickness direction, the surface opposite a surface joined to the tube 10, is exposed to the air passage formed between the tubes 10. Specifically, the bent portion 23 and the tube 10 are joined by brazing.

[0066] The fin body portion 24 is provided between the bent portions 23 adjacent to each other along the corrugated shape of the fin 20, and is connected to each of the bent portions 23 so as to connect the bent portions 23 to each other. Here, the wording “the bent portions 23 adjacent to each other along the corrugated shape” means the bent portions 23 adjacent to each other on a virtual waveform curve when the virtual waveform curve along the corrugated shape is assumed.

[0067] The fin body portion 24 is R-bent at both ends of the fin body portion 24 in the tube array direction DRst. That is, the fin body portion 24 includes a pair of curved portions 24A provided at both ends of the fin body portion 24 in the tube array direction DRst, and a body intermediate portion 24B provided between the pair of curved portions 24A. The pair of curved portions 24A is curved and connected to the bent portions 23 adjacent to the fin body portion 24 on both sides.

[0068] In addition, the fin body portion 24 includes a plurality of louvers 24C having a shape in which part of the fin body portion 24 is cut and raised. The plurality of louvers 24C is provided side by side in the air passage direction AF.

[0069] The plurality of louvers 24C is included in the body intermediate portion 24B of the fin body portion 24. The louver 24C includes a louver body portion 24D including a central portion of the louver 24C in the tube array direction DRst, one louver end 24E, and the other louver end 24F.

[0070] The louver body portion 24D has a flat plate shape inclined with respect to the air passage direction AF and guides the air along the louver body portion 24D. That is, a gap through which air passes is formed between the louver body portions 24D of the louvers 24C adjacent to each other in the air passage direction AF.

[0071] The one louver end 24E has a plate shape extending from the louver body portion 24D to one side in the tube array direction DRst, and is provided at one end of the louver 24C in the tube array direction DRst. The one louver end 24E is formed so that the plate thickness direction of the one louver end 24E intersects the plate thickness direction of the louver body portion 24D.

[0072] The one louver end 24E is on an opposite side of the curved portion 24A across the louver body portion 24D in the tube array direction DRst and is connected to the curved portion 24A. The curved portion 24A constitutes a portion of the fin body portion 24 around the louver 24C. The curved portion 24A to which the one louver end 24E is connected is one of the pair of curved portions 24A provided with the body intermediate portion 24B interposed therebetween in the tube array direction DRst.

[0073] The other louver end 24F has a plate shape extending from the louver body portion 24D to the other side in the tube array direction DRst, and is provided at the other end of the louver 24C in the tube array direction DRst. The other louver end 24F is formed so that the plate thickness direction of the other louver end 24F intersects the plate thickness direction of the louver body portion 24D.

[0074] The other louver end 24F is connected to the curved portion 24A constituting a portion of the fin body portion 24, the portion being around the louver 24C, the portion being opposite to the louver body portion 24D in the tube array direction DRst. The curved portion 24A to which the other louver end 24F is connected is the other of the pair of curved portions 24A in the tube array direction DRst, the pair of curved portions 24A being provided side by side across the body intermediate portion 24B.

[0075] All the louvers 24C included in one fin body portion 24 are divided into a plurality of louver groups. Each louver group includes a plurality of louvers 24C in which the louver body portions 24D are provided in parallel to each other at predetermined intervals. 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 an arrow FLf in FIG. 2. In other words, the air meanders while passing between the louvers 24C and swinging in the tube extending direction DRt with the fin body portion 24 interposed therebetween. Since the air flows in a meandering manner as described above, it is possible to improve the performance of heat exchange between the refrigerant and the air. The plurality of louvers 24C need not be divided into the plurality of louver groups.

[0076] The body intermediate portion 24B of the fin body portion 24 includes the plurality of louvers 24C described above, but a portion other than the louvers 24C is formed in a flat plate shape. Specifically, the body intermediate portion 24B includes a plurality of flat portions 24G formed along the air passage direction AF. The plurality of flat portions 24G is provided side by side in the air passage direction AF with respect to the louvers 24C. For example, the plurality of flat portions 24G is provided at one end of the body intermediate portion 24B in the air passage direction AF, the other end of the body intermediate portion 24B in the air passage direction AF, and an intermediate portion. The flat portion 24G of the intermediate portion of the body intermediate portion 24B in the air passage direction AF is provided between the plurality of louvers 24C of the body intermediate portion 24B.

[0077] As illustrated in FIG. 3, the fins 20 are provided across the first array group 10A and the second array group 10B of the tube 10. The outer surface 21 of the fin 20 has a first region 21A and a second region 21B having higher hydrophilicity than the first region 21A. A wavy line in FIG. 3 indicates a boundary between the first region 21A and the second region 21B.

[0078] Specifically, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B in the first fin body region 21C of the outer surface 21, the first fin body region 21C being located between the adjacent tubes 10 constituting the first array group 10A, that is, between the tubes 10. Similarly, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B in the second fin body region 21D of the outer surface 21, the second fin body region 21D being located between the adjacent tubes 10 constituting the second array group 10B, that is, between the tubes 10.

[0079] The second region 21B is provided adjacent to a partial region 12A of the joint portion 12 of the tube 10 and the fin 20. Each of the fin body regions 21C and 21D is constituted by a region of the body intermediate portion 24B and the curved portion 24A of the outer surface 21 of the fin 20. Therefore, the second region 21B is constituted by part of the outer surface 21 corresponding to the body intermediate portion 24B and the curved portion 24A of the fin 20.

[0080] The joint portion 12 is a portion where part of the tube wall face 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 portion 12 is a region where part of the tube wall face 11 of the tube 10 and the bent portion 23 of the fin 20 overlap each other. The shape of the overlapping region is, for example, a quadrangular shape. The portion, of the joint portion 12, exposed to the outside is a linear range along the air passage direction AF. Therefore, it can be said that the partial region 12A of the joint portion 12 is part of the linear range exposed to the outside of the joint portion 12. That is, the second region 21B is provided adjacent to part of the linear range exposed to the outside of the joint portion 12.

[0081] Further, the adjacent disposition means that, for example, the second region 21B is connected to part of the linear range exposed to the outside of the joint portion 12. That is, the second region 21B and the joint portion 12 are connected. Alternatively, in the adjacent disposition, the second region 21B and the joint portion 12 do not need to be connected, and the second region 21B and the partial region 12A of the joint portion 12 may be provided very close to each other.

[0082] In the present embodiment, the second region 21B is provided adjacent to both the partial region 12A of the joint portion 12 of one of the adjacent tubes 10 and the partial region 12A of the joint portion 12 of the other of the adjacent tubes 10. That is, the second region 21B is set from the end to the end in the tube array direction DRst. Similarly, the first region 21A is provided adjacent to both the partial region 12A of the joint portion 12 of one of the adjacent tubes 10 and the partial region 12A of the joint portion 12 of the other of the adjacent tubes 10. In this case, the first region 21A is constituted by part of the outer surface 21 corresponding to the body intermediate portion 24B and the curved portion 24A of the fin 20, as in the second region 21B.

[0083] In the first fin body region 21C, the first region 21A and the second region 21B are provided in order of the first region 21A, the second region 21B, and the first region 21A along the air passage direction AF. Similarly, in the second fin body region 21D, the first region 21A and the second region 21B are provided in order of the first region 21A, the second region 21B, and the first region 21A along the air passage direction AF. That is, in each of the fin body regions 21C and 21D, one second region 21B is provided between two first regions 21A.

[0084] As illustrated in FIGS. 4 and 5, the second region 21B of the first fin body region 21C has a plurality of the grooves 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. Similarly, the second region 21B of the second fin body region 21D has the grooves 22.

[0085] In FIG. 4, point hatching is applied to the groove 22 in order to clearly illustrate the groove 22. The same applies to the drawings described later. Further, a wavy line in FIG. 4 indicates a boundary between the curved portion 24A and the body intermediate portion 24B.

[0086] The groove 22 has an uneven shape formed on the outer surface 21 of the fin 20. As a result, in each of the fin body regions 21C and 21D, the second region 21B has higher hydrophilicity than the first region 21A. That is, the outer surface 21 of the fin 20 does not entirely have the groove 22, and only part of each of the fin body regions 21C and 21D has the groove 22.

[0087] Here, that the groove 22 is formed to increase the hydrophilicity of the outer surface 21 of the fin 20 means that the groove 22 is formed to increase the hydrophilicity of the outer surface 21 of the fin 20, as compared with a case where the outer surface 21 of the fin 20 is a smooth surface without unevenness.

[0088] The groove 22 is formed along a direction away from the joint portion 12 in a face direction of the outer surface 21 of the fin 20 with a position in the partial region 12A of the joint portion 12 as a starting point 12B. In the present embodiment, the groove 22 is formed along the tube array direction DRst. That is, the groove 22 extends in a direction perpendicular to the tube wall face 11.

[0089] Since the groove 22 is only required to extend with a position in the partial region 12A of the joint portion 12 as the starting point 12B, the groove 22 may be formed in the curved portion 24A or need not be formed in the curved portion 24A. That is, the groove 22 may or need not be connected to the tube wall face 11. In the present embodiment, the groove 22 is formed in the curved portion 24A and is connected to the tube wall face 11.

[0090] When only the flat portion 24G is located in the second region 21B, the groove 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 22 is formed in the flat portion 24G and the louver body portion 24D. Of course, even when both the flat portion 24G and the louver body portion 24D are located in the second region 21B, the groove 22 may be formed only in the flat portion 24G, or the groove 22 may be formed only in the louver body portion 24D.

[0091] The width in which the plurality of the grooves 22 is provided in the air passage direction AF is set to, for example, 30% or less of the entire width of the fin 20. That is, the width of the second region 21B in the air passage direction AF is 30% or less of the entire width of the fin 20.

[0092] The plurality of the grooves 22 is provided side by side with a predetermined groove pitch at intervals. Each of the plurality of the grooves 22 extends in one direction along the outer surface 21 of the fin 20 and is provided in parallel. Each of the plurality of the grooves 22 is formed to be recessed by a predetermined groove depth Hg with respect to the outer surface 21 of the fin 20.

[0093] In FIG. 5, a plate thickness direction DRf of the fin 20 is illustrated, but as for each portion of the fin 20, the plate thickness direction DRf is the plate thickness direction of each portion. That is, the plate thickness direction DRf of the fin 20 is a plate thickness direction of the fin body portion 24 for the fin body portion 24, a plate thickness direction of the bent portion 23 for the bent portion 23, and a plate thickness direction of the louver 24C for the louver 24C.

[0094] Further, the plurality of the grooves 22 on the outer surface 21 of the fin 20 is formed, for example, before the fin 20 is formed into a corrugated shape. Therefore, the plurality of the grooves 22 on the outer surface 21 of the fin 20 includes grooves continuously extending over the plurality of portions 12, 24A, 24B, 24D, 24E, 24F, and 24G constituting the fin 20.

[0095] Here, the groove depth of the groove 22 is, for example, 10 μm or more at any portion of the outer surface 21 of the fin 20. The groove depth is a depth of the recessed portion with the outer surface 21 of the fin 20 as a reference. 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 retention of the condensed water on the outer surface 21 of the fin 20. As the groove depth Hg increases, the hydrophilicity of the outer surface 21 of the fin 20 increases.

[0096] The groove pitch of the plurality of the grooves 22 is, for example, 0.2 mm or less. The groove pitch is, for example, a distance between width centers of adjacent grooves 22 in the air passage direction AF. The smaller the groove pitch, the higher the hydrophilicity of the outer surface 21 of the fin 20. In other words, as the number of the plurality of the grooves 22 increases, the hydrophilicity of the outer surface 21 of the fin 20 increases.

[0097] The groove width of the plurality of the grooves 22 is, for example, 10 μm or more. The groove width is a width of a recessed portion of the groove 22 in the air passage direction AF. The smaller the groove width, the higher the hydrophilicity of the outer surface 21 of the fin 20.

[0098] In the present embodiment, the second region 21B is provided at the central portion in the air passage direction AF between the tubes 10. That is, the groove 22 is located at the central portion in the air passage direction AF between the tubes 10. Although the groove 22 has a structure in which the fin 20 is thinned, since the second region 21B is located at the central portion in the air passage direction AF, the central portion can be supported by the end of the fin 20. Therefore, the strength of the fin 20 can be ensured. In addition, there is an advantage that the groove 22 can be easily formed at the central portion, as compared with the case where the groove 22 is formed at the end of the fin 20 in the air passage direction AF. Therefore, the productivity of the fin 20 can be improved.

[0099] The plate-shaped member constituting the fin 20 has both of one face and the other face. In addition, the fin 20 is bent in a corrugated shape. Therefore, the outer surface 21 of the fin 20 is repeatedly provided in order of one face, the other face, the other face, and one face of the plate-shaped member in the tube extending direction DRt. The first region 21A and the second region 21B may be set on at least one of one face and the other face of the plate-shaped member. In the present embodiment, the first region 21A and the second region 21B are set on both faces of one face and the other face of the plate-shaped member. In addition, the position of the groove 22 on one face of the plate-shaped member and the position of the groove 22 on the other face of the plate-shaped member may overlap or deviate 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 22 on one face of the plate-shaped member and the position of the groove 22 on the other face deviate in the plate thickness direction DRf of the fin 20.

[0100] Next, evaporation of condensed water generated in heat exchanger 1 will be described. First, the generated amount of condensed water changes according to the load situation of the heat exchanger 1. For example, at a high load of the refrigeration cycle, the generated amount of condensed water is large.

[0101] FIG. 6 is a diagram for describing the high drain mode in a case where the generated amount of condensed water Wc is large. The upper part of FIG. 6 illustrates the amount of the condensed water Wc in the air passage direction AF, the middle part of FIG. 6 illustrates the drain mode in a case of a partial groove where the groove 22 is formed in part of the outer surface 21 of the fin 20, and the lower part of FIG. 6 illustrates the drain mode in a case of no groove where the groove 22 is not formed in the outer surface 21 of the fin 20.

[0102] Each of the middle part and lower part of FIG. 6 corresponds to the view taken along arrow III in FIG. 2, and the arrows indicate the moving direction of the condensed water Wc. In addition, the condensed water Wc retained in the curved portion 24A of the fin 20 is represented by a thick line, and the same applies to FIGS. 7, 9, and 10 below.

[0103] When the generated amount of the condensed water Wc is large, a large amount of the condensed water Wc is generated in the curved portion 24A of the fin 20 and the outer surface 21 of the fin 20. As illustrated in the upper part of FIG. 6, when air flows between the tubes 10 from the first array group 10A in the air passage direction AF, there is a peak of the amount of condensed water between the tubes 10 constituting the first array group 10A. It can also be said that the second region 21B of the outer surface 21 of the fin 20, the second region 21B having the groove 22, is provided in accordance with the position of the peak of the amount of condensed water.

[0104] In addition, the amount of condensed water decreases toward downstream in the air passage direction AF, that is, toward between the tubes 10 of the second array group 10B. A peak of the amount of condensed water does not occur between the tubes 10 constituting the second array group 10B.

[0105] Since the generated amount of the condensed water Wc is large at the time of high load of the refrigeration cycle, the water droplets of the condensed water Wc are easily connected to each other. As illustrated in the middle part of FIG. 6, since the second region 21B and the groove 22 are provided at the center position in the air passage direction AF where the condensed water Wc is most generated, the condensed water Wc can be drawn into the second region 21B from the first regions 21A located on both sides of the second region 21B having the groove 22. The condensed water Wc in the second region 21B can be transported to the tube wall face 11 along the groove 22. As a result, the condensed water Wc can be drained along the tube 10.

[0106] Since the amount of the condensed water Wc is large, the water droplets of the condensed water Wc are easily connected to each other also in the first region 21A. Therefore, the condensed water Wc flows from the first region 21A to the tube wall face 11 and is drained along the tube 10.

[0107] As opposed to the drain mode described above, in the case of no groove, the water droplets of the condensed water Wc are connected to each other on the outer surface 21 of the fin 20, flow to the tube wall face 11, and are drained along the tube 10. Since the outer surface 21 of the fin 20 does not have the groove 22, the ability to draw the condensed water Wc to the center position in the air passage direction AF and the ability to transport the condensed water Wc to the tube wall face 11 are lower than those in a case where the outer surface 21 of the fin 20 has the groove 22. That is, although the condensed water Wc is drained, the drainage ability is lower than that in the case where the groove 22 is provided.

[0108] At a low load of the refrigeration cycle, the generated amount of the condensed water Wc is smaller than that at a high load. In this case, the water droplets of the condensed water Wc are hardly connected to each other. The condensed water Wc evaporates. Of course, the condensed water Wc is easily drawn into the groove 22 provided in the second region 21B of the outer surface 21 of the fin 20. When the amount of the condensed water Wc in the second region 21B increases, the condensed water Wc is appropriately drained from the tube wall face 11 to the tube 10 via the groove 22.

[0109] Next, a case where the condensed water Wc evaporates at once at the time of switching between inside and outside air at the time of low load of the refrigeration cycle, at the time of crossing the dew point at the time of OFF of the compressor, at the time of fuel consumption control, and the like will be described with reference to FIGS. 7 and 8. Each figure in FIG. 7 corresponds to the view taken along arrow III in FIG. 2. In FIG. 7, the condensed water Wc retained 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.

[0110] The difference in the manner of evaporation of the condensed water Wc is represented for each of the case of the entire groove in the left side of FIG. 7 where the entire outer surface 21 of the fin 20 has the groove 22, the case of a partial groove in the center of FIG. 7, and the case of no groove in the right side of FIG. 7. Here, in the case of the entire groove, since the entire outer surface 21 of the fin 20 has the groove 22, it can be said that the entire outer surface 21 is the second region 21B. In addition, in the case of no groove, since the outer surface 21 of the fin 20 has no groove 22, it can be said that the entire outer surface 21 is the first region 21A. In FIG. 7, the elapse of time is represented from the upper side to the lower side of the paper surface, and the elapse of time is longer toward the lower side of the paper surface. In FIG. 7, the time elapsed is the shortest in the case of the entire groove in the left part, and the time elapsed is the longest in the case of no groove in the right part.

[0111] First, as illustrated on the right side of FIG. 7, in the case of no groove, the heat exchanger 1 gradually exchanges heat with warm air at the first array group 10A that is located on the windward side in the air passage direction AF. As a result, the outer surface 21 of the fin 20 gradually dries from the windward to the leeward in the air passage direction AF. However, the condensed water Wc retained in a fillet portion of the tube 10 and the fin 20, that is, the curved portion 24A of the fin 20, is retained in a narrow minimum region. Therefore, the condensed water Wc of the curved portion 24A dries more slowly after the entire outer surface 21 of the fin 20 is dried. 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 retained in the curved portion 24A is represented by a thick line.

[0112] Therefore, as illustrated in FIG. 8, in the case of no groove, the evaporation rate of the condensed water Wc is very low. In addition, it takes a long time until all the condensed water Wc is evaporated.

[0113] Next, as illustrated on the left side of FIG. 7, in the case of the entire groove, the condensed water Wc retained in the groove 22 exchanges heat with warm air. As a result, while the outer surface 21 of the fin 20 is dried, the condensed water Wc retained in the curved portion 24A of the fin 20 by the groove 22 of the outer surface 21 of the fin 20 is drawn into the outer surface 21 of the fin 20 by the capillary phenomenon of the groove 22. Therefore, the curved portion 24A of the fin 20 also starts to dry before the entire outer surface 21 of the fin 20 finishes drying. That is, the high drainage property of the groove 22 hinders the movement of the condensed water Wc to the tube wall face 11, and promotes the evaporation of the condensed water Wc on the outer surface 21 of the fin 20.

[0114] Therefore, as illustrated in FIG. 8, in the case of the entire groove, the evaporation rate of the condensed water Wc rapidly increases in a short time, and exceeds a threshold value serving as a reference for odor generation. As a result, the odor component dissolved in the condensed water Wc is released at once. In addition, as illustrated in FIG. 9, the odor component is released at once from the entire region between the tubes 10 in the outer surface 21 of the fin 20. Therefore, there is a possibility that the user feels a smell. The odor component is, for example, an odor component in the vehicle interior, an adhesive as a component of the vehicle, a component contained in sweat of the user, or the like.

[0115] Subsequently, as illustrated in the center of FIG. 7, in the case of the partial groove, as in the case of the entire groove, while drying the outer surface 21 of the fin 20, the groove 22 of the second region 21B draws the condensed water Wc retained in the curved portion 24A of the fin 20 into the second region 21B by the capillary phenomenon of the groove 22.

[0116] However, the region where the condensed water Wc is drawn into the groove 22 is only the second region 21B, of the outer surface 21 of the fin 20, between the tubes. In other words, it can be said that the region of the outer surface 21 of the fin 20, the region having the groove 22, is divided into the second region 21B of the first array group 10A and the second region 21B of the second array group 10B. Therefore, the area of the region where the condensed water Wc is drawn into the groove 22 is smaller than that in the case where the entire outer surface 21 of the fin 20 has the groove 22. Accordingly, the amount of the condensed water Wc drawn from the curved portion 24A of the fin 20 into the groove 22 of the second region 21B of the fin 20 is 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 the odor component is suppressed at the time of evaporation of the condensed water Wc. Therefore, as illustrated in FIG. 10, for the odor component, the odor component can be reduced in the amount released from the outer surface 21 of the fin 20 between the tubes 10. In addition, it is possible to prevent the user from feeling a smell.

[0117] In addition, since the second region 21B having the groove 22 between the tubes 10 is located at the central portion in the air passage direction AF, the relative humidity of the air is high downstream of the second region 21B. Therefore, also from this, the evaporation rate of the condensed water Wc can be reduced.

[0118] Therefore, as illustrated in FIG. 8, the evaporation rate of the condensed water Wc is ensured to such an extent that the threshold value serving as the reference of odor generation is not exceeded, as compared with the case of the entire groove, and the time until all the condensed water Wc evaporates can be lengthened.

[0119] In FIG. 7, the difference in the elapse of time between the entire groove, the partial groove, and no groove is only schematically illustrated. Therefore, the difference is independent of the actual time difference between the entire groove, the partial groove, and no groove.

[0120] As described above, in the present embodiment, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B having higher hydrophilicity than the first region 21A. The second region 21B has the groove 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. Furthermore, the second region 21B is provided adjacent to the partial region 12A of the joint portion 12 of the tube 10 and the fin 20.

[0121] Accordingly, the region where the condensed water Wc is drawn by the groove 22 is only the second region 21B. Therefore, the region where the condensed water Wc is drawn can be made smaller than that in the case where the condensed water Wc is drawn into the entire fin body regions 21C and 21D by the groove 22.

[0122] Therefore, in a situation where the generation of the condensed water Wc is small and in a situation where the condensed water Wc evaporates at once, the evaporation rate of the condensed water Wc in each of the fin body regions 21C and 21D can be decreased. Therefore, it is possible to suppress the instant release of the odor component contained in the condensed water Wc. In addition, in a situation where a large amount of the condensed water Wc is generated, the condensed water Wc can be appropriately drained to the tube 10 via the groove 22 of the fin 20. Therefore, it is possible to suppress odor while ensuring the drainage property of the fin 20.Second Embodiment

[0123] In the present embodiment, differences from the first embodiment will be mainly described. The present embodiment is different from the first embodiment in the form of the groove 22. FIGS. 11 to 14 illustrate a groove pattern of the grooves 22 of the first array group 10A.

[0124] For example, as illustrated in FIG. 11, the groove 22 is formed along the tube array direction DRst and is formed along the air passage direction AF. That is, the groove 22 extends in two directions. The groove 22 along the tube array direction DRst and the groove 22 along the air passage direction AF intersect at a right angle. Therefore, the groove 22 is formed in a lattice shape. Accordingly, more condensed water Wc can be drawn into the second region 21B by the groove 22.

[0125] The groove 22 in the two directions does not necessarily intersect at a right angle, and may intersect at an angle other than the right angle. The groove 22 is not limited to being formed in two directions, but may be formed in three or more directions.

[0126] Alternatively, as illustrated in FIGS. 12 and 13, the groove 22 may be formed along a direction inclined with respect to the tube array direction DRst.

[0127] Alternatively, as illustrated in FIG. 14, the grooves 22 may be formed in a staggered shape along the tube array direction DRst. The staggered shape is a state in which the grooves 22 are intermittently formed along the tube array direction DRst and are alternately provided along the air passage direction AF. By ensuring two or more levels of plate thickness, rigidity (strength) of the fin 20 can be ensured.

[0128] For example, the grooves 22 may be formed on both faces of the plate-shaped member, the grooves 22 may be provided in a staggered manner on both the front face and the back face of the plate-shaped member, the second regions 21B may be located at substantially the center in the air passage direction AF between the tubes 10, and the second regions 21B may be equally provided on the left and right between the tubes 10 of the array groups 10A and 10B. The staggered grooves 22 may overlap or deviate in the plate thickness direction DRf of the fin 20. In addition, when the second region 21B is located at the central portion in the air passage direction AF between the tubes 10, the upstream first region 21A and the downstream first region 21A in the air passage direction AF may be set to have the same area.

[0129] Here, the term “left and right” represents the upstream first array group 10A and the downstream second array group 10B in the air passage direction AF. For example, in FIG. 3, the first array group 10A is located on the left side and the second array group 10B is located on the right side on the paper surface. The term “equally” means that the regions (second regions 21B) having the grooves 22 have the same area between the left side and the right side, and are located at the same central positions between the left side and the right side in the air passage direction AF between the tubes 10. Therefore, the term “equally provided on the left and right” means that the respective second regions 21B of the array groups 10A and 10B have the same area and are located at the same central portion between the tubes 10 in the air passage direction AF.

[0130] In each drawing illustrating the groove 22 as illustrated in FIGS. 12 to 14, the plurality of the grooves 22 provided on the outer surface 21 of the fin 20 is schematically and purposely larger than the actual size for the sake of description. In addition, there is no particular limitation in the direction in which the plurality of the grooves 22 extend, that is, the one direction along the outer surface 21 of the fin 20.

[0131] FIGS. 11 to 14 illustrate the groove 22 of the first array group 10A, and the form of the groove 22 of the second array group 10B is the same as that of the first array group 10A. Of course, the form of the groove 22 of the first array group 10A and the form of the groove 22 of the second array group 10B may be different. Alternatively, the first array group 10A may have the groove 22, and the second array group 10B may not have the groove 22.

[0132] As described above, when the groove 22 is formed along the direction away from the joint portion 12 with the position of the joint portion 12 in the partial region 12A as the starting point 12B, the groove 22 is not limited to one linear shape, but can be changed to another form.Third Embodiment

[0133] In the present embodiment, differences from the first and second embodiments will be mainly described. In the present embodiment, the first region 21A also has the groove 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. However, the first region 21A has the groove 22 so that hydrophilicity of the second region 21B is higher than hydrophilicity of the first region 21A.

[0134] For example, as illustrated in FIG. 15, the depth of the groove 22 formed in the second region 21B is deeper than the depth of the groove 22 formed in the first region 21A. The depth of the groove 22 formed in the first region 21A is, for example, 10 μm or more, and the depth of the groove 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these depths are an example, and may be set to other depths.

[0135] Alternatively, as illustrated in FIG. 16, the groove width of the groove 22 formed in the second region 21B is smaller than the groove width of the groove 22 formed in the first region 21A. The groove width of the groove 22 formed in the first region 21A is, for example, 10 μm or more, and the groove width of the groove 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these groove widths are an example, and other groove widths may be set.

[0136] 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 may be densely provided, and the grooves 22 in the first region 21A may be coarsely provided. Alternatively, the groove pitch of the grooves 22 may be made constant by adjusting the depth and the groove width of the groove 22.

[0137] Alternatively, as illustrated in FIG. 17, the number of the grooves 22 formed in the second region 21B is larger than the number of the grooves 22 formed in the first region 21A. The number of grooves is compared, for example, by the number of grooves in a certain area.

[0138] For example, the number of the grooves 22 formed in the second region 21B is 2 to 10 times the number of the 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 provided, and the grooves 22 in the first region 21A are coarsely provided. The number of the grooves 22 is an example, and other numbers may be set.

[0139] The groove depth, the groove width, and the number of the grooves 22 of the first array group 10A and the groove depth, the groove width, and the number of the grooves 22 of the second array group 10B may be the same or different. In addition, the groove depth, the groove width, and the number in a certain area of the grooves 22 of the second region 21B are not necessarily uniform, and may be different in the second region 21B. For example, in the second region 21B, the groove depths of the grooves 22 may be gradually smaller toward the first region 21A. Similarly, in the first region 21A, the groove depth, the groove width, and the number in a certain area of the grooves 22 may not be uniform.

[0140] As described above, in order to cause a difference in hydrophilicity between the first region 21A and the second region 21B, the depth, the groove width, and the number of the grooves 22 can be adjusted. Of course, the depth, the groove width, and the number illustrated in FIGS. 15 to 17 may be combined. Further, the depth, the groove width, and the number of the grooves 22 can also be applied to the groove 22 illustrated in FIGS. 11 to 14 of the second embodiment.

[0141] The present disclosure is not limited to the above-described embodiments, and can be variously modified as follows without departing from the gist of the present disclosure. For example, the above-described embodiments may be appropriately combined, or the above-described embodiments may be variously modified.

[0142] (1) In each of the embodiments described above, the heat exchanger 1 is applied to the evaporator, but the present invention is not limited to this aspect. For example, the present invention can also be applied to other heat exchangers such as a cooler core in which condensed water is generated.

[0143] (2) The heat exchanger 1 has a configuration in which the ends of the plurality of tubes 10 are brazed and layered and provided with respect to the first tank 30 and the second tank 40, but the present invention is not limited to this aspect.

[0144] The heat exchanger 1 can adopt various aspects as long as the heat exchanger 1 includes a core portion configured by layering and disposing a plurality of tubes and a pair of tanks provided at the ends of the tubes. For example, the present invention can also be applied to a configuration in which a tube is formed by joining a pair of facing plate members having a recess having a predetermined shape, and the pairs of plate members are layered and provided to form a heat exchanger having a pair of tanks and a plurality of tubes.

[0145] (3) The second region 21B may be provided adjacent to at least one of the partial region 12A of the joint portion 12 at one of the adjacent tubes 10 and the partial region 12A of the joint portion 12 at the other of the adjacent tubes 10, and need not be provided adjacent to both.

[0146] (4) The shape of the first region 21A and the second region 21B taken along arrow III is not limited to the quadrangular shape, but may be another shape such as a trapezoidal shape. The first region 21A and the second region 21B are not limited to a quadrangular shape or the like, and may have any shape including a curve. Further, the boundary line between the first region 21A and the second region 21B is not limited to a straight line, but may be a curved line.

[0147] (5) Between adjacent tubes 10, the second region 21B of the outer surface 21 of the fin 20 need not be provided to be sandwiched between the two first regions 21A. For example, one first region 21A and one second region 21B of the outer surface 21 of the fin 20 may be provided between adjacent tubes 10. Alternatively, the first region 21A and the second region 21B may be alternately provided in the air passage direction AF. In this case, the number of the first regions 21A and the number of the second regions 21B may be the same or different. For example, the two first regions 21A and the two second regions 21B may be alternately provided, or the second regions 21B may be provided between the three first regions 21A.

[0148] (6) The groove 22 need not be linearly laid out. The groove 22 may be laid out in a curved shape, for example. Alternatively, the groove 22 may be laid out including a straight portion and a curved portion.

[0149] (7) The tube 10 need not be a flat tube having a flat cross-sectional shape, but a tube having another shape. For example, the tube wall face 11 may have a curved shape so that the tube 10 has a cylindrical shape. In this case, for example, the groove 22 is formed so as to be inclined with respect to the tangent of the tube wall face 11 with the partial region 12A of the joint portion 12 as the starting point 12B. Alternatively, the groove 22 may be formed so as to be inclined with respect to the normal line of the tube 10 with the partial region 12A of the joint portion 12 as the starting point 12B.

[0150] (8) The region of the outer surface 21 of the fin 20, the region having the groove 22, is not limited to the curved portion 24A, the flat portion 24G, and the louver body portion 24D. For example, each of the one louver end 24E and the other louver end 24F may have the groove 22.

[0151] (9) The outer surface 21 of the fin 20 may be subjected to a surface treatment for improving hydrophilicity. For example, the entire fin 20 is coated with a hydrophilic resin having high water resistance such as polyvinyl alcohol.

[0152] (10) The fin 20 need not have the louver 24C.

[0153] Although the present disclosure is described in accordance with examples, it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various modification examples and modifications within an equivalent range. In addition, various combinations and modes, and other combinations and modes including only one element, more elements, or less elements therein are within the scope and idea of the present disclosure.

[0154] The technical features of the heat exchanger disclosed herein are as follows.(Item 1)

[0155] A heat exchanger includes: a tube (10) configured to cause first fluid to flow therethrough; and a fin (20) formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid. An outer surface (21) of the fin includes a first region (21A) and a second region (21B), the second region having higher hydrophilicity than the first region. The second region has a groove (22) configured to improve hydrophilicity of the outer surface. The second region is adjacent to a partial region (12A) of a joint portion (12), which is between the tube and the fin.(Item 2)

[0156] The heat exchanger according to item 1, in which the tube extends in a tube extending direction (DRt), a plurality of the tubes, which are arranged in a tube array direction (DRst) that intersects the tube extending direction, constitutes an array group (10A, 10B), the fin is provided between adjacent tubes constituting the array group, and the first region and the second region are arranged, such that the first region, the second region, and the first region are arranged in this order along a second fluid flow direction, which intersects the tube extending direction and the tube array direction, in a fin body region (21C, 21D) of the outer surface of the fin, the fin body region being located between the adjacent tubes.(Item 3)

[0157] The heat exchanger according to item 2, in which the array group includes a first array group (10A) and a second array group (10B) arranged in the second fluid flow direction, and the fin is arranged across the first array group and the second array group. The first region and the second region are provided, such that in a first fin body region (21C) of the outer surface of the fin, which is located between the adjacent tubes constituting the first array group, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction, and in a second fin body region (21D) of the outer surface of the fin, which is located between the adjacent tubes constituting the second array group, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction.(Item 4)

[0158] The heat exchanger according to any one of items 1 to 3, in which the groove is formed from a starting point (12B), which is in the partial region of the joint portion, along a direction away from the joint portion.(Item 5)

[0159] The heat exchanger according to any one of items 1 to 4, in which the first region has the groove configured to improve hydrophilicity of the outer surface of the fin, and a depth of the groove formed in the second region is larger than a depth of the groove formed in the first region.(Item 6)

[0160] The heat exchanger according to any one of items 1 to 5, in which the first region has the groove configured to improve hydrophilicity of the outer surface of the fin, and a groove width of the groove formed in the second region is smaller than a groove width of the groove formed in the first region.(Item 7)

[0161] The heat exchanger according to any one of items 1 to 6, in which the first region has the groove configured to improve hydrophilicity of the outer surface of the fin, and a number of the grooves formed in the second region is larger than a number of the grooves formed in the first region.

Examples

first embodiment

[0036]The heat exchanger according to the present embodiment is used, for example, as an evaporator constituting part of a refrigeration cycle that performs air conditioning in a vehicle interior of a vehicle. The refrigeration cycle includes, for example, a compressor, a condenser, an expansion valve, and an evaporator. The evaporator is provided inside an air conditioning case through which blown air to be blown into the vehicle interior flows.

[0037]Therefore, the evaporator exchanges heat between the low-pressure refrigerant as the first fluid in 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 causing the low-pressure refrigerant to absorb heat from the blown air. That is, the evaporator is a cooling heat exchanger for cooling air by latent heat of vaporization of the refrigerant.

[0038]Hereinafter, the first embodiment will be described with reference to FIGS. 1...

second embodiment

[0123]In the present embodiment, differences from the first embodiment will be mainly described. The present embodiment is different from the first embodiment in the form of the groove 22. FIGS. 11 to 14 illustrate a groove pattern of the grooves 22 of the first array group 10A.

[0124]For example, as illustrated in FIG. 11, the groove 22 is formed along the tube array direction DRst and is formed along the air passage direction AF. That is, the groove 22 extends in two directions. The groove 22 along the tube array direction DRst and the groove 22 along the air passage direction AF intersect at a right angle. Therefore, the groove 22 is formed in a lattice shape. Accordingly, more condensed water Wc can be drawn into the second region 21B by the groove 22.

[0125]The groove 22 in the two directions does not necessarily intersect at a right angle, and may intersect at an angle other than the right angle. The groove 22 is not limited to being formed in two directions, but may be formed i...

third embodiment

[0133]In the present embodiment, differences from the first and second embodiments will be mainly described. In the present embodiment, the first region 21A also has the groove 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. However, the first region 21A has the groove 22 so that hydrophilicity of the second region 21B is higher than hydrophilicity of the first region 21A.

[0134]For example, as illustrated in FIG. 15, the depth of the groove 22 formed in the second region 21B is deeper than the depth of the groove 22 formed in the first region 21A. The depth of the groove 22 formed in the first region 21A is, for example, 10 μm or more, and the depth of the groove 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these depths are an example, and may be set to other depths.

[0135]Alternatively, as illustrated in FIG. 16, the groove width of the groove 22 formed in the second region 21B is smaller than the groove width of the groov...

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application is a continuation application of International Patent Application No. PCT / JP2024 / 029386 filed on Aug. 20, 2024, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2023-146860 filed on Sep. 11, 2023. The entire disclosures of all of the above applications are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to a heat exchanger.BACKGROUND

[0003] Conventionally, a known heat exchanger includes a tube and a fin that promotes heat exchange between fluid flowing in the tube and fluid flowing outside the tube.SUMMARY

[0004] According to an aspect of the present disclosure, a heat exchanger comprises: a tube configured to cause first fluid to flow therethrough; and a fin formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid. An outer surface of the fin includes a first region and a second region, the second region having higher hydrophilicity than the first region. The second region has a groove configured to improve hydrophilicity of the outer surface. The second region is adjacent to a partial region of a joint portion, which is between the tube and the fin.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. In the accompanying drawings:

[0006] FIG. 1 is a perspective view of a heat exchanger according to a first embodiment;

[0007] FIG. 2 is an enlarged perspective view of part of a tube and a fin of the heat exchanger in FIG. 1;

[0008] FIG. 3 is a view taken along arrow III in FIG. 2;

[0009] FIG. 4 is an enlarged plan view schematically illustrating a groove by enlarging and illustrating part of a joint portion of a tube and a fin in a second region of an outer surface of the fin in the first embodiment;

[0010] FIG. 5 is a sectional view taken along line V-V in FIG. 4;

[0011] FIG. 6 is a diagram for describing a high drain mode in which a generated amount of condensed water is large, in which the upper part shows an amount of condensed water corresponding to a position in an air passage direction, the middle part shows a drain mode in a case where a groove is formed in part of an outer surface of a fin, and the lower part shows a drain mode in a case where no groove is formed in the outer surface of the fin;

[0012] FIG. 7 is a diagram for describing how condensed water generated in the heat exchanger evaporates in a case where the entire outer surface of the fin has the groove, in a case where the groove is provided in part of the outer surface of the fin, and in a case where no groove is provided in the outer surface of the fin;

[0013] FIG. 8 is a diagram illustrating the relationship between the evaporation rate of the condensed water and the time until the evaporation of the condensed water is completed in a case where the entire outer surface of the fin has the groove, in a case where the groove is provided in part of the outer surface of the fin, and in a case where no groove is provided in the outer surface of the fin;

[0014] FIG. 9 is a perspective view illustrating a state in which a large amount of odor component is released in a case where the entire outer surface of the fin has the groove;

[0015] FIG. 10 is a perspective view illustrating a state in which a small amount of odor component is released in a case where part of the outer surface of the fin has the groove;

[0016] FIG. 11 is a plan view schematically illustrating a groove formed in a second region in a second embodiment;

[0017] FIG. 12 is a plan view schematically illustrating a groove formed in a second region in the second embodiment;

[0018] FIG. 13 is a plan view schematically illustrating a groove formed in a second region in the second embodiment;

[0019] FIG. 14 is a diagram illustrating a groove formed in a second region in the second embodiment;

[0020] FIG. 15 is an enlarged cross-sectional view illustrating some grooves formed in a first region and a second region in a third embodiment;

[0021] FIG. 16 is an enlarged plan view illustrating some grooves formed in a first region and a second region in the third embodiment; and

[0022] FIG. 17 is an enlarged plan view illustrating some grooves formed in a first region and a second region in the third embodiment.DETAILED DESCRIPTION

[0023] Hereinafter, examples of the present disclosure will be described.

[0024] According to an example of the present disclosure, a heat exchanger includes a tube, though which a first fluid flows, and a fin that promotes heat exchange between a second fluid, which flows outside the tube, and the first fluid. In the heat exchanger, condensed water may be generated according to a load state of the heat exchanger, and the condensed water may be retained on the outer surface of the fin. Therefore, in order to improve the drainage property of the fin. For example, an assumable heat exchanger may have a groove in its entire surface of a fin.

[0025] For example, when a refrigeration cycle including the heat exchanger operates under a high load, a large amount of condensed water is generated in the heat exchanger. For this reason, the condensed water generated on the outer surface of the fin easily merges with each other by forming a water film on the entire surface, and may be easily drained to the tube through the groove.

[0026] On the other hand, the amount of condensed water generated in the heat exchanger is small during a low-load operation of the refrigeration cycle. Therefore, the condensed water flowing on the tube and the condensed water retained in the joint portion of the fin and the tube are drawn into the central portion of the fin due to the capillary phenomenon of the groove, and the condensed water remains on the outer surface of the fin. That is, the groove for improving the drainage property of the condensed water conversely deteriorates the drainage property during the low-load operation of the refrigeration cycle.

[0027] In the refrigeration cycle, particularly during the low-load operation, in a case where a compressor is turned ON and OFF, or in a case where the low pressure is increased for power saving, when the temperature of the fin rises and the condensed water remaining on the outer surface of the fin evaporates at once, odor component contained in the condensed water is released all at once. As a result, there is a possibility that an odor is generated.

[0028] According to an example of the present disclosure, a heat exchanger comprises: a tube configured to cause first fluid to flow therethrough; and a fin formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid.

[0029] An outer surface of the fin includes a first region and a second region, the second region having higher hydrophilicity than the first region.

[0030] The second region has a groove configured to improve hydrophilicity of the outer surface.

[0031] The second region is adjacent to a partial region of a joint portion, which is between the tube and the fin.

[0032] Accordingly, only the second region has high hydrophilicity in the region of the outer surface of the fin provided adjacent to the joint portion of the tube and the fin. Therefore, the area into which the condensed water is drawn can be made smaller than that in a case where the condensed water is drawn into the entire region provided adjacent to the joint portion by the groove.

[0033] Therefore, in a situation where the generation of the condensed water is small, the evaporation rate of the condensed water in the region of the outer surface of the fin provided adjacent to the joint portion of the tube and the fin can be decreased. Therefore, in a situation where the condensed water evaporates at once, it is possible to suppress the instant release of the odor component contained in the condensed water. In addition, in a situation where a large amount of condensed water is generated, the condensed water can be drained to the tube via the groove of the fin.

[0034] Therefore, in a situation where the condensed water evaporates at once, it is possible to suppress the odor while ensuring the drainage property of the fin.

[0035] Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment are denoted by the same reference numerals, and redundant description may be omitted. In a case where only part of the configuration is described in each embodiment, other embodiments precedingly described can be applied to the other parts of the configuration. It is possible to not only combine portions specifically indicating that combinations are possible in the respective embodiments, but also partially combine the embodiments even if it is not explicitly described unless there is a problem in the combination.First Embodiment

[0036] The heat exchanger according to the present embodiment is used, for example, as an evaporator constituting part of a refrigeration cycle that performs air conditioning in a vehicle interior of a vehicle. The refrigeration cycle includes, for example, a compressor, a condenser, an expansion valve, and an evaporator. The evaporator is provided inside an air conditioning case through which blown air to be blown into the vehicle interior flows.

[0037] Therefore, the evaporator exchanges heat between the low-pressure refrigerant as the first fluid in 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 causing the low-pressure refrigerant to absorb heat from the blown air. That is, the evaporator is a cooling heat exchanger for cooling air by latent heat of vaporization of the refrigerant.

[0038] Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 10. As illustrated in FIGS. 1 and 2, a heat exchanger 1 includes a plurality of tubes 10, a plurality of fins 20, a first tank 30, a second tank 40, an outer frame member 50, and a pipe connection member 60. These members are made of, for example, an aluminum alloy, and the members are joined to each other by brazing. An arrow DRg in FIG. 1 indicates an up and down direction DRg of the heat exchanger 1.

[0039] An outer surface 21 of the fin 20 has a plurality of the grooves 22 (see FIGS. 4 and 5) as described later. However, since the groove 22 is extremely fine as compared to the size of the fin 20, it is not illustrated in FIGS. 2 and 3. The same applies to other drawings, which will be described later, illustrating the fin 20 except for the enlarged view of the groove 22.

[0040] As illustrated in FIG. 3, the plurality of tubes 10 is provided at predetermined intervals in a tube array direction DRst. Air passing through the heat exchanger 1 flows between the plurality of tubes 10. That is, the air flows between the adjacent tubes 10 in the tube array direction DRst. Between the tubes 10, the air flows with one side of an air passage direction AF as the upstream side (windward) and the other side of the air passage direction AF as the downstream side (leeward). In other words, the air passage direction AF is a second fluid flow direction.

[0041] The air passing through the heat exchanger 1 flows between the tubes 10 and is cooled by the refrigerant to generate condensed water. That is, the air passing through the heat exchanger 1 is a gas that generates condensed water by heat exchange with the refrigerant.

[0042] The tube 10 is a flat tube having a flat cross-sectional shape with the tube array direction DRst as a short-side direction and the air passage direction AF as a longitudinal direction. The plurality of tubes 10 constitute a first array group 10A and a second array group 10B each of which has the plurality of tubes 10 provided in the tube array direction DRst intersecting a tube extending direction DRt. The tube extending direction DRt is a direction in which the tube 10 extends.

[0043] The first array group 10A and the second array group 10B are provided in the air passage direction AF. That is, the plurality of tubes 10 is provided in two rows on one side and the other side of the air passage direction AF. In the present embodiment, in the air passage direction AF, the first array group 10A is located upstream of the air flow, and the second array group 10B is located downstream of the air flow.

[0044] As illustrated in FIG. 1, each of the plurality of tubes 10 is formed so as to extend linearly along the tube extending direction DRt from one end to the other end. The refrigerant flows inside each tube 10. The tube extending direction DRt does not necessarily coincide with the up and down direction DRg. In the present embodiment, the tube extending direction DRt coincides with the up and down direction DRg. Each of the tubes 10 of the present embodiment extends in the up and down direction DRg, that is, in the vertical direction DRg.

[0045] The air passage direction AF, the tube array direction DRst, and the tube extending direction DRt intersect each other, and strictly, are directions orthogonal to each other.

[0046] The plurality of tubes 10 is inserted into the first tank 30 at the upper end, and inserted into the second tank 40 at the lower end. The first tank 30 and the second tank 40 distribute the refrigerant to the plurality of tubes 10 and collect the refrigerant flowing from the plurality of tubes 10.

[0047] Each of the tanks 30 and 40 is formed in a tubular shape using the same material as the tube 10. Each of the tanks 30 and 40 is formed in a shape extending in the tube array direction DRst. The term “tubular shape” includes not only a cylindrical shape but also a polygonal tubular shape such as a quadrangular tubular shape.

[0048] The inside of the first tank 30 has an internal space which the refrigerant of the refrigeration cycle flows into and out of. The internal space of the first tank 30 is divided into an upstream side and a downstream side in the air passage direction AF. That is, the first tank 30 includes a first leeward tank 31 located downstream in the air passage direction AF and a first windward tank 32 located upstream in the air passage direction AF.

[0049] The first windward tank 32 is connected to and communicates with one end of each of the plurality of windward tubes 10 upstream of the first tank 30 in the air passage direction AF. The first windward tank 32 functions as a collecting tank that collects the refrigerant passing through the plurality of windward tubes 10.

[0050] On the other hand, the first leeward tank 31 is connected to and communicates with one end of each of the plurality of leeward tubes 10 downstream of the first tank 30 in the air passage direction AF. The first leeward tank 31 functions as a distribution tank that distributes the refrigerant to the plurality of leeward tubes 10.

[0051] In the heat exchanger 1 according to the first embodiment, the second tank 40 is provided at the lower part of the heat exchanger 1 in the up and down direction DRg. The second tank 40 is joined to the lower end of each tube 10 by brazing.

[0052] The inside of the second tank 40 has an internal space which the refrigerant of the refrigeration cycle flows into and out of. The internal space of the second tank 40 is divided into the windward and the leeward. That is, the second tank 40 includes a second leeward tank 41 located downstream in the air passage direction AF and a second windward tank 42 located upstream in the air passage direction AF.

[0053] The second windward tank 42 is connected to and communicates with the other end of each of the plurality of windward tubes 10 upstream of the second tank 40 in the air passage direction AF. The second windward tank 42 functions as a distribution tank that distributes the refrigerant to the plurality of windward tubes 10.

[0054] On the other hand, the second leeward tank 41 is connected to and communicates with the other end of each of the plurality of leeward tubes 10 downstream of the second tank 40 in the air passage direction AF. The second leeward tank 41 functions as a collecting tank that collects the refrigerant having passed through the plurality of leeward tubes 10.

[0055] The second leeward tank 41 communicates with the second windward tank 42 inside the second tank 40. Therefore, the second tank 40 can supply the refrigerant collected in the second leeward tank 41 to the second windward tank 42 and distribute the refrigerant to the windward tubes 10 at the second windward tank 42.

[0056] Since air flows between the plurality of tubes 10, the gap formed between the tubes 10 is an air passage through which air flows. The fins 20 are provided at the air passage. In other words, the fin 20 is provided between the adjacent tubes 10 in the tube array direction DRst. Therefore, the fin 20 is an outer fin provided outside the tube 10.

[0057] The fin 20 promotes heat exchange between the refrigerant flowing inside the tube 10 and air flowing between the tubes 10. Specifically, the fin 20 increases the area for the heat transfer between the refrigerant flowing inside the tube 10 and the air flowing outside the tube 10 to increase the heat exchange efficiency between the refrigerant and the air.

[0058] In the tube array direction DRst, a pair of outer frame members 50 is provided further outside the portion where the plurality of tubes 10 and the plurality of fins 20 are alternately provided. The pipe connection member 60 is fixed to one of the pair of outer frame members 50.

[0059] The pipe connection member 60 is a refrigerant pipe connection member in the refrigeration cycle. The pipe connection member 60 is joined to a side face of the first tank 30 at one end in the tube array direction DRst by brazing.

[0060] The pipe connection member 60 has a refrigerant inflow port 61 to which a refrigerant is supplied and a refrigerant outflow port 62 for discharging the refrigerant. An outlet of the expansion valve in the refrigeration cycle is connected to the refrigerant inflow port 61 via a refrigerant pipe. A refrigerant inflow passage (not illustrated) is connected to the refrigerant inflow port 61. The refrigerant inflow passage is formed inside the pipe connection member 60 and connects the refrigerant inflow port 61 and the internal space of the first leeward tank 31.

[0061] On the other hand, a suction port of the compressor in the refrigeration cycle is connected to the refrigerant outflow port 62 via a refrigerant pipe. A refrigerant outflow passage (not illustrated) is connected to the refrigerant outflow port 62. The refrigerant outflow passage is formed inside the pipe connection member 60 and connects the refrigerant outflow port 62 and the internal space of the first windward tank 32.

[0062] The refrigerant flowing from the refrigerant inflow port 61 into the first tank 30 flows through the internal space of each of the tanks 30 and 40 and the plurality of tubes 10 in a predetermined path, and flows out from the refrigerant outflow port 62. At this time, the air flowing through the air passage provided with the fins 20 is cooled by latent heat of vaporization of the refrigerant flowing through the tanks 30 and 40 and the plurality of tubes 10.

[0063] The fin 20 is a component that promotes heat exchange between air flowing outside the tube 10 and the refrigerant. As illustrated in FIG. 2, the fin 20 is formed by bending a plate-shaped member. Specifically, the fin 20 is bent to form a continuous corrugated shape in the tube extending direction DRt. The fin 20 is, for example, a corrugated fin.

[0064] The fin 20 includes a plurality of bent portions 23 and a plurality of fin body portions 24. The plurality of bent portions 23 constitute corrugated top portions of the fin 20. Since the bent portion 23 constitutes the corrugated top portion of the fin 20, it is referred to as a fin TOP portion.

[0065] The bent portion 23 is joined to a tube wall face 11 which is a side face of the tube 10, the side face facing in the tube array direction DRst. That is, a surface of the surfaces on both sides of the bent portion 23 in the plate thickness direction, the surface opposite a surface joined to the tube 10, is exposed to the air passage formed between the tubes 10. Specifically, the bent portion 23 and the tube 10 are joined by brazing.

[0066] The fin body portion 24 is provided between the bent portions 23 adjacent to each other along the corrugated shape of the fin 20, and is connected to each of the bent portions 23 so as to connect the bent portions 23 to each other. Here, the wording “the bent portions 23 adjacent to each other along the corrugated shape” means the bent portions 23 adjacent to each other on a virtual waveform curve when the virtual waveform curve along the corrugated shape is assumed.

[0067] The fin body portion 24 is R-bent at both ends of the fin body portion 24 in the tube array direction DRst. That is, the fin body portion 24 includes a pair of curved portions 24A provided at both ends of the fin body portion 24 in the tube array direction DRst, and a body intermediate portion 24B provided between the pair of curved portions 24A. The pair of curved portions 24A is curved and connected to the bent portions 23 adjacent to the fin body portion 24 on both sides.

[0068] In addition, the fin body portion 24 includes a plurality of louvers 24C having a shape in which part of the fin body portion 24 is cut and raised. The plurality of louvers 24C is provided side by side in the air passage direction AF.

[0069] The plurality of louvers 24C is included in the body intermediate portion 24B of the fin body portion 24. The louver 24C includes a louver body portion 24D including a central portion of the louver 24C in the tube array direction DRst, one louver end 24E, and the other louver end 24F.

[0070] The louver body portion 24D has a flat plate shape inclined with respect to the air passage direction AF and guides the air along the louver body portion 24D. That is, a gap through which air passes is formed between the louver body portions 24D of the louvers 24C adjacent to each other in the air passage direction AF.

[0071] The one louver end 24E has a plate shape extending from the louver body portion 24D to one side in the tube array direction DRst, and is provided at one end of the louver 24C in the tube array direction DRst. The one louver end 24E is formed so that the plate thickness direction of the one louver end 24E intersects the plate thickness direction of the louver body portion 24D.

[0072] The one louver end 24E is on an opposite side of the curved portion 24A across the louver body portion 24D in the tube array direction DRst and is connected to the curved portion 24A. The curved portion 24A constitutes a portion of the fin body portion 24 around the louver 24C. The curved portion 24A to which the one louver end 24E is connected is one of the pair of curved portions 24A provided with the body intermediate portion 24B interposed therebetween in the tube array direction DRst.

[0073] The other louver end 24F has a plate shape extending from the louver body portion 24D to the other side in the tube array direction DRst, and is provided at the other end of the louver 24C in the tube array direction DRst. The other louver end 24F is formed so that the plate thickness direction of the other louver end 24F intersects the plate thickness direction of the louver body portion 24D.

[0074] The other louver end 24F is connected to the curved portion 24A constituting a portion of the fin body portion 24, the portion being around the louver 24C, the portion being opposite to the louver body portion 24D in the tube array direction DRst. The curved portion 24A to which the other louver end 24F is connected is the other of the pair of curved portions 24A in the tube array direction DRst, the pair of curved portions 24A being provided side by side across the body intermediate portion 24B.

[0075] All the louvers 24C included in one fin body portion 24 are divided into a plurality of louver groups. Each louver group includes a plurality of louvers 24C in which the louver body portions 24D are provided in parallel to each other at predetermined intervals. 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 an arrow FLf in FIG. 2. In other words, the air meanders while passing between the louvers 24C and swinging in the tube extending direction DRt with the fin body portion 24 interposed therebetween. Since the air flows in a meandering manner as described above, it is possible to improve the performance of heat exchange between the refrigerant and the air. The plurality of louvers 24C need not be divided into the plurality of louver groups.

[0076] The body intermediate portion 24B of the fin body portion 24 includes the plurality of louvers 24C described above, but a portion other than the louvers 24C is formed in a flat plate shape. Specifically, the body intermediate portion 24B includes a plurality of flat portions 24G formed along the air passage direction AF. The plurality of flat portions 24G is provided side by side in the air passage direction AF with respect to the louvers 24C. For example, the plurality of flat portions 24G is provided at one end of the body intermediate portion 24B in the air passage direction AF, the other end of the body intermediate portion 24B in the air passage direction AF, and an intermediate portion. The flat portion 24G of the intermediate portion of the body intermediate portion 24B in the air passage direction AF is provided between the plurality of louvers 24C of the body intermediate portion 24B.

[0077] As illustrated in FIG. 3, the fins 20 are provided across the first array group 10A and the second array group 10B of the tube 10. The outer surface 21 of the fin 20 has a first region 21A and a second region 21B having higher hydrophilicity than the first region 21A. A wavy line in FIG. 3 indicates a boundary between the first region 21A and the second region 21B.

[0078] Specifically, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B in the first fin body region 21C of the outer surface 21, the first fin body region 21C being located between the adjacent tubes 10 constituting the first array group 10A, that is, between the tubes 10. Similarly, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B in the second fin body region 21D of the outer surface 21, the second fin body region 21D being located between the adjacent tubes 10 constituting the second array group 10B, that is, between the tubes 10.

[0079] The second region 21B is provided adjacent to a partial region 12A of the joint portion 12 of the tube 10 and the fin 20. Each of the fin body regions 21C and 21D is constituted by a region of the body intermediate portion 24B and the curved portion 24A of the outer surface 21 of the fin 20. Therefore, the second region 21B is constituted by part of the outer surface 21 corresponding to the body intermediate portion 24B and the curved portion 24A of the fin 20.

[0080] The joint portion 12 is a portion where part of the tube wall face 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 portion 12 is a region where part of the tube wall face 11 of the tube 10 and the bent portion 23 of the fin 20 overlap each other. The shape of the overlapping region is, for example, a quadrangular shape. The portion, of the joint portion 12, exposed to the outside is a linear range along the air passage direction AF. Therefore, it can be said that the partial region 12A of the joint portion 12 is part of the linear range exposed to the outside of the joint portion 12. That is, the second region 21B is provided adjacent to part of the linear range exposed to the outside of the joint portion 12.

[0081] Further, the adjacent disposition means that, for example, the second region 21B is connected to part of the linear range exposed to the outside of the joint portion 12. That is, the second region 21B and the joint portion 12 are connected. Alternatively, in the adjacent disposition, the second region 21B and the joint portion 12 do not need to be connected, and the second region 21B and the partial region 12A of the joint portion 12 may be provided very close to each other.

[0082] In the present embodiment, the second region 21B is provided adjacent to both the partial region 12A of the joint portion 12 of one of the adjacent tubes 10 and the partial region 12A of the joint portion 12 of the other of the adjacent tubes 10. That is, the second region 21B is set from the end to the end in the tube array direction DRst. Similarly, the first region 21A is provided adjacent to both the partial region 12A of the joint portion 12 of one of the adjacent tubes 10 and the partial region 12A of the joint portion 12 of the other of the adjacent tubes 10. In this case, the first region 21A is constituted by part of the outer surface 21 corresponding to the body intermediate portion 24B and the curved portion 24A of the fin 20, as in the second region 21B.

[0083] In the first fin body region 21C, the first region 21A and the second region 21B are provided in order of the first region 21A, the second region 21B, and the first region 21A along the air passage direction AF. Similarly, in the second fin body region 21D, the first region 21A and the second region 21B are provided in order of the first region 21A, the second region 21B, and the first region 21A along the air passage direction AF. That is, in each of the fin body regions 21C and 21D, one second region 21B is provided between two first regions 21A.

[0084] As illustrated in FIGS. 4 and 5, the second region 21B of the first fin body region 21C has a plurality of the grooves 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. Similarly, the second region 21B of the second fin body region 21D has the grooves 22.

[0085] In FIG. 4, point hatching is applied to the groove 22 in order to clearly illustrate the groove 22. The same applies to the drawings described later. Further, a wavy line in FIG. 4 indicates a boundary between the curved portion 24A and the body intermediate portion 24B.

[0086] The groove 22 has an uneven shape formed on the outer surface 21 of the fin 20. As a result, in each of the fin body regions 21C and 21D, the second region 21B has higher hydrophilicity than the first region 21A. That is, the outer surface 21 of the fin 20 does not entirely have the groove 22, and only part of each of the fin body regions 21C and 21D has the groove 22.

[0087] Here, that the groove 22 is formed to increase the hydrophilicity of the outer surface 21 of the fin 20 means that the groove 22 is formed to increase the hydrophilicity of the outer surface 21 of the fin 20, as compared with a case where the outer surface 21 of the fin 20 is a smooth surface without unevenness.

[0088] The groove 22 is formed along a direction away from the joint portion 12 in a face direction of the outer surface 21 of the fin 20 with a position in the partial region 12A of the joint portion 12 as a starting point 12B. In the present embodiment, the groove 22 is formed along the tube array direction DRst. That is, the groove 22 extends in a direction perpendicular to the tube wall face 11.

[0089] Since the groove 22 is only required to extend with a position in the partial region 12A of the joint portion 12 as the starting point 12B, the groove 22 may be formed in the curved portion 24A or need not be formed in the curved portion 24A. That is, the groove 22 may or need not be connected to the tube wall face 11. In the present embodiment, the groove 22 is formed in the curved portion 24A and is connected to the tube wall face 11.

[0090] When only the flat portion 24G is located in the second region 21B, the groove 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 22 is formed in the flat portion 24G and the louver body portion 24D. Of course, even when both the flat portion 24G and the louver body portion 24D are located in the second region 21B, the groove 22 may be formed only in the flat portion 24G, or the groove 22 may be formed only in the louver body portion 24D.

[0091] The width in which the plurality of the grooves 22 is provided in the air passage direction AF is set to, for example, 30% or less of the entire width of the fin 20. That is, the width of the second region 21B in the air passage direction AF is 30% or less of the entire width of the fin 20.

[0092] The plurality of the grooves 22 is provided side by side with a predetermined groove pitch at intervals. Each of the plurality of the grooves 22 extends in one direction along the outer surface 21 of the fin 20 and is provided in parallel. Each of the plurality of the grooves 22 is formed to be recessed by a predetermined groove depth Hg with respect to the outer surface 21 of the fin 20.

[0093] In FIG. 5, a plate thickness direction DRf of the fin 20 is illustrated, but as for each portion of the fin 20, the plate thickness direction DRf is the plate thickness direction of each portion. That is, the plate thickness direction DRf of the fin 20 is a plate thickness direction of the fin body portion 24 for the fin body portion 24, a plate thickness direction of the bent portion 23 for the bent portion 23, and a plate thickness direction of the louver 24C for the louver 24C.

[0094] Further, the plurality of the grooves 22 on the outer surface 21 of the fin 20 is formed, for example, before the fin 20 is formed into a corrugated shape. Therefore, the plurality of the grooves 22 on the outer surface 21 of the fin 20 includes grooves continuously extending over the plurality of portions 12, 24A, 24B, 24D, 24E, 24F, and 24G constituting the fin 20.

[0095] Here, the groove depth of the groove 22 is, for example, 10 μm or more at any portion of the outer surface 21 of the fin 20. The groove depth is a depth of the recessed portion with the outer surface 21 of the fin 20 as a reference. 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 retention of the condensed water on the outer surface 21 of the fin 20. As the groove depth Hg increases, the hydrophilicity of the outer surface 21 of the fin 20 increases.

[0096] The groove pitch of the plurality of the grooves 22 is, for example, 0.2 mm or less. The groove pitch is, for example, a distance between width centers of adjacent grooves 22 in the air passage direction AF. The smaller the groove pitch, the higher the hydrophilicity of the outer surface 21 of the fin 20. In other words, as the number of the plurality of the grooves 22 increases, the hydrophilicity of the outer surface 21 of the fin 20 increases.

[0097] The groove width of the plurality of the grooves 22 is, for example, 10 μm or more. The groove width is a width of a recessed portion of the groove 22 in the air passage direction AF. The smaller the groove width, the higher the hydrophilicity of the outer surface 21 of the fin 20.

[0098] In the present embodiment, the second region 21B is provided at the central portion in the air passage direction AF between the tubes 10. That is, the groove 22 is located at the central portion in the air passage direction AF between the tubes 10. Although the groove 22 has a structure in which the fin 20 is thinned, since the second region 21B is located at the central portion in the air passage direction AF, the central portion can be supported by the end of the fin 20. Therefore, the strength of the fin 20 can be ensured. In addition, there is an advantage that the groove 22 can be easily formed at the central portion, as compared with the case where the groove 22 is formed at the end of the fin 20 in the air passage direction AF. Therefore, the productivity of the fin 20 can be improved.

[0099] The plate-shaped member constituting the fin 20 has both of one face and the other face. In addition, the fin 20 is bent in a corrugated shape. Therefore, the outer surface 21 of the fin 20 is repeatedly provided in order of one face, the other face, the other face, and one face of the plate-shaped member in the tube extending direction DRt. The first region 21A and the second region 21B may be set on at least one of one face and the other face of the plate-shaped member. In the present embodiment, the first region 21A and the second region 21B are set on both faces of one face and the other face of the plate-shaped member. In addition, the position of the groove 22 on one face of the plate-shaped member and the position of the groove 22 on the other face of the plate-shaped member may overlap or deviate 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 22 on one face of the plate-shaped member and the position of the groove 22 on the other face deviate in the plate thickness direction DRf of the fin 20.

[0100] Next, evaporation of condensed water generated in heat exchanger 1 will be described. First, the generated amount of condensed water changes according to the load situation of the heat exchanger 1. For example, at a high load of the refrigeration cycle, the generated amount of condensed water is large.

[0101] FIG. 6 is a diagram for describing the high drain mode in a case where the generated amount of condensed water Wc is large. The upper part of FIG. 6 illustrates the amount of the condensed water Wc in the air passage direction AF, the middle part of FIG. 6 illustrates the drain mode in a case of a partial groove where the groove 22 is formed in part of the outer surface 21 of the fin 20, and the lower part of FIG. 6 illustrates the drain mode in a case of no groove where the groove 22 is not formed in the outer surface 21 of the fin 20.

[0102] Each of the middle part and lower part of FIG. 6 corresponds to the view taken along arrow III in FIG. 2, and the arrows indicate the moving direction of the condensed water Wc. In addition, the condensed water Wc retained in the curved portion 24A of the fin 20 is represented by a thick line, and the same applies to FIGS. 7, 9, and 10 below.

[0103] When the generated amount of the condensed water Wc is large, a large amount of the condensed water Wc is generated in the curved portion 24A of the fin 20 and the outer surface 21 of the fin 20. As illustrated in the upper part of FIG. 6, when air flows between the tubes 10 from the first array group 10A in the air passage direction AF, there is a peak of the amount of condensed water between the tubes 10 constituting the first array group 10A. It can also be said that the second region 21B of the outer surface 21 of the fin 20, the second region 21B having the groove 22, is provided in accordance with the position of the peak of the amount of condensed water.

[0104] In addition, the amount of condensed water decreases toward downstream in the air passage direction AF, that is, toward between the tubes 10 of the second array group 10B. A peak of the amount of condensed water does not occur between the tubes 10 constituting the second array group 10B.

[0105] Since the generated amount of the condensed water Wc is large at the time of high load of the refrigeration cycle, the water droplets of the condensed water Wc are easily connected to each other. As illustrated in the middle part of FIG. 6, since the second region 21B and the groove 22 are provided at the center position in the air passage direction AF where the condensed water Wc is most generated, the condensed water Wc can be drawn into the second region 21B from the first regions 21A located on both sides of the second region 21B having the groove 22. The condensed water Wc in the second region 21B can be transported to the tube wall face 11 along the groove 22. As a result, the condensed water Wc can be drained along the tube 10.

[0106] Since the amount of the condensed water Wc is large, the water droplets of the condensed water Wc are easily connected to each other also in the first region 21A. Therefore, the condensed water Wc flows from the first region 21A to the tube wall face 11 and is drained along the tube 10.

[0107] As opposed to the drain mode described above, in the case of no groove, the water droplets of the condensed water Wc are connected to each other on the outer surface 21 of the fin 20, flow to the tube wall face 11, and are drained along the tube 10. Since the outer surface 21 of the fin 20 does not have the groove 22, the ability to draw the condensed water Wc to the center position in the air passage direction AF and the ability to transport the condensed water Wc to the tube wall face 11 are lower than those in a case where the outer surface 21 of the fin 20 has the groove 22. That is, although the condensed water Wc is drained, the drainage ability is lower than that in the case where the groove 22 is provided.

[0108] At a low load of the refrigeration cycle, the generated amount of the condensed water Wc is smaller than that at a high load. In this case, the water droplets of the condensed water Wc are hardly connected to each other. The condensed water Wc evaporates. Of course, the condensed water Wc is easily drawn into the groove 22 provided in the second region 21B of the outer surface 21 of the fin 20. When the amount of the condensed water Wc in the second region 21B increases, the condensed water Wc is appropriately drained from the tube wall face 11 to the tube 10 via the groove 22.

[0109] Next, a case where the condensed water Wc evaporates at once at the time of switching between inside and outside air at the time of low load of the refrigeration cycle, at the time of crossing the dew point at the time of OFF of the compressor, at the time of fuel consumption control, and the like will be described with reference to FIGS. 7 and 8. Each figure in FIG. 7 corresponds to the view taken along arrow III in FIG. 2. In FIG. 7, the condensed water Wc retained 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.

[0110] The difference in the manner of evaporation of the condensed water Wc is represented for each of the case of the entire groove in the left side of FIG. 7 where the entire outer surface 21 of the fin 20 has the groove 22, the case of a partial groove in the center of FIG. 7, and the case of no groove in the right side of FIG. 7. Here, in the case of the entire groove, since the entire outer surface 21 of the fin 20 has the groove 22, it can be said that the entire outer surface 21 is the second region 21B. In addition, in the case of no groove, since the outer surface 21 of the fin 20 has no groove 22, it can be said that the entire outer surface 21 is the first region 21A. In FIG. 7, the elapse of time is represented from the upper side to the lower side of the paper surface, and the elapse of time is longer toward the lower side of the paper surface. In FIG. 7, the time elapsed is the shortest in the case of the entire groove in the left part, and the time elapsed is the longest in the case of no groove in the right part.

[0111] First, as illustrated on the right side of FIG. 7, in the case of no groove, the heat exchanger 1 gradually exchanges heat with warm air at the first array group 10A that is located on the windward side in the air passage direction AF. As a result, the outer surface 21 of the fin 20 gradually dries from the windward to the leeward in the air passage direction AF. However, the condensed water Wc retained in a fillet portion of the tube 10 and the fin 20, that is, the curved portion 24A of the fin 20, is retained in a narrow minimum region. Therefore, the condensed water Wc of the curved portion 24A dries more slowly after the entire outer surface 21 of the fin 20 is dried. 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 retained in the curved portion 24A is represented by a thick line.

[0112] Therefore, as illustrated in FIG. 8, in the case of no groove, the evaporation rate of the condensed water Wc is very low. In addition, it takes a long time until all the condensed water Wc is evaporated.

[0113] Next, as illustrated on the left side of FIG. 7, in the case of the entire groove, the condensed water Wc retained in the groove 22 exchanges heat with warm air. As a result, while the outer surface 21 of the fin 20 is dried, the condensed water Wc retained in the curved portion 24A of the fin 20 by the groove 22 of the outer surface 21 of the fin 20 is drawn into the outer surface 21 of the fin 20 by the capillary phenomenon of the groove 22. Therefore, the curved portion 24A of the fin 20 also starts to dry before the entire outer surface 21 of the fin 20 finishes drying. That is, the high drainage property of the groove 22 hinders the movement of the condensed water Wc to the tube wall face 11, and promotes the evaporation of the condensed water Wc on the outer surface 21 of the fin 20.

[0114] Therefore, as illustrated in FIG. 8, in the case of the entire groove, the evaporation rate of the condensed water Wc rapidly increases in a short time, and exceeds a threshold value serving as a reference for odor generation. As a result, the odor component dissolved in the condensed water Wc is released at once. In addition, as illustrated in FIG. 9, the odor component is released at once from the entire region between the tubes 10 in the outer surface 21 of the fin 20. Therefore, there is a possibility that the user feels a smell. The odor component is, for example, an odor component in the vehicle interior, an adhesive as a component of the vehicle, a component contained in sweat of the user, or the like.

[0115] Subsequently, as illustrated in the center of FIG. 7, in the case of the partial groove, as in the case of the entire groove, while drying the outer surface 21 of the fin 20, the groove 22 of the second region 21B draws the condensed water Wc retained in the curved portion 24A of the fin 20 into the second region 21B by the capillary phenomenon of the groove 22.

[0116] However, the region where the condensed water Wc is drawn into the groove 22 is only the second region 21B, of the outer surface 21 of the fin 20, between the tubes. In other words, it can be said that the region of the outer surface 21 of the fin 20, the region having the groove 22, is divided into the second region 21B of the first array group 10A and the second region 21B of the second array group 10B. Therefore, the area of the region where the condensed water Wc is drawn into the groove 22 is smaller than that in the case where the entire outer surface 21 of the fin 20 has the groove 22. Accordingly, the amount of the condensed water Wc drawn from the curved portion 24A of the fin 20 into the groove 22 of the second region 21B of the fin 20 is 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 the odor component is suppressed at the time of evaporation of the condensed water Wc. Therefore, as illustrated in FIG. 10, for the odor component, the odor component can be reduced in the amount released from the outer surface 21 of the fin 20 between the tubes 10. In addition, it is possible to prevent the user from feeling a smell.

[0117] In addition, since the second region 21B having the groove 22 between the tubes 10 is located at the central portion in the air passage direction AF, the relative humidity of the air is high downstream of the second region 21B. Therefore, also from this, the evaporation rate of the condensed water Wc can be reduced.

[0118] Therefore, as illustrated in FIG. 8, the evaporation rate of the condensed water Wc is ensured to such an extent that the threshold value serving as the reference of odor generation is not exceeded, as compared with the case of the entire groove, and the time until all the condensed water Wc evaporates can be lengthened.

[0119] In FIG. 7, the difference in the elapse of time between the entire groove, the partial groove, and no groove is only schematically illustrated. Therefore, the difference is independent of the actual time difference between the entire groove, the partial groove, and no groove.

[0120] As described above, in the present embodiment, the outer surface 21 of the fin 20 has the first region 21A and the second region 21B having higher hydrophilicity than the first region 21A. The second region 21B has the groove 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. Furthermore, the second region 21B is provided adjacent to the partial region 12A of the joint portion 12 of the tube 10 and the fin 20.

[0121] Accordingly, the region where the condensed water Wc is drawn by the groove 22 is only the second region 21B. Therefore, the region where the condensed water Wc is drawn can be made smaller than that in the case where the condensed water Wc is drawn into the entire fin body regions 21C and 21D by the groove 22.

[0122] Therefore, in a situation where the generation of the condensed water Wc is small and in a situation where the condensed water Wc evaporates at once, the evaporation rate of the condensed water Wc in each of the fin body regions 21C and 21D can be decreased. Therefore, it is possible to suppress the instant release of the odor component contained in the condensed water Wc. In addition, in a situation where a large amount of the condensed water Wc is generated, the condensed water Wc can be appropriately drained to the tube 10 via the groove 22 of the fin 20. Therefore, it is possible to suppress odor while ensuring the drainage property of the fin 20.Second Embodiment

[0123] In the present embodiment, differences from the first embodiment will be mainly described. The present embodiment is different from the first embodiment in the form of the groove 22. FIGS. 11 to 14 illustrate a groove pattern of the grooves 22 of the first array group 10A.

[0124] For example, as illustrated in FIG. 11, the groove 22 is formed along the tube array direction DRst and is formed along the air passage direction AF. That is, the groove 22 extends in two directions. The groove 22 along the tube array direction DRst and the groove 22 along the air passage direction AF intersect at a right angle. Therefore, the groove 22 is formed in a lattice shape. Accordingly, more condensed water Wc can be drawn into the second region 21B by the groove 22.

[0125] The groove 22 in the two directions does not necessarily intersect at a right angle, and may intersect at an angle other than the right angle. The groove 22 is not limited to being formed in two directions, but may be formed in three or more directions.

[0126] Alternatively, as illustrated in FIGS. 12 and 13, the groove 22 may be formed along a direction inclined with respect to the tube array direction DRst.

[0127] Alternatively, as illustrated in FIG. 14, the grooves 22 may be formed in a staggered shape along the tube array direction DRst. The staggered shape is a state in which the grooves 22 are intermittently formed along the tube array direction DRst and are alternately provided along the air passage direction AF. By ensuring two or more levels of plate thickness, rigidity (strength) of the fin 20 can be ensured.

[0128] For example, the grooves 22 may be formed on both faces of the plate-shaped member, the grooves 22 may be provided in a staggered manner on both the front face and the back face of the plate-shaped member, the second regions 21B may be located at substantially the center in the air passage direction AF between the tubes 10, and the second regions 21B may be equally provided on the left and right between the tubes 10 of the array groups 10A and 10B. The staggered grooves 22 may overlap or deviate in the plate thickness direction DRf of the fin 20. In addition, when the second region 21B is located at the central portion in the air passage direction AF between the tubes 10, the upstream first region 21A and the downstream first region 21A in the air passage direction AF may be set to have the same area.

[0129] Here, the term “left and right” represents the upstream first array group 10A and the downstream second array group 10B in the air passage direction AF. For example, in FIG. 3, the first array group 10A is located on the left side and the second array group 10B is located on the right side on the paper surface. The term “equally” means that the regions (second regions 21B) having the grooves 22 have the same area between the left side and the right side, and are located at the same central positions between the left side and the right side in the air passage direction AF between the tubes 10. Therefore, the term “equally provided on the left and right” means that the respective second regions 21B of the array groups 10A and 10B have the same area and are located at the same central portion between the tubes 10 in the air passage direction AF.

[0130] In each drawing illustrating the groove 22 as illustrated in FIGS. 12 to 14, the plurality of the grooves 22 provided on the outer surface 21 of the fin 20 is schematically and purposely larger than the actual size for the sake of description. In addition, there is no particular limitation in the direction in which the plurality of the grooves 22 extend, that is, the one direction along the outer surface 21 of the fin 20.

[0131] FIGS. 11 to 14 illustrate the groove 22 of the first array group 10A, and the form of the groove 22 of the second array group 10B is the same as that of the first array group 10A. Of course, the form of the groove 22 of the first array group 10A and the form of the groove 22 of the second array group 10B may be different. Alternatively, the first array group 10A may have the groove 22, and the second array group 10B may not have the groove 22.

[0132] As described above, when the groove 22 is formed along the direction away from the joint portion 12 with the position of the joint portion 12 in the partial region 12A as the starting point 12B, the groove 22 is not limited to one linear shape, but can be changed to another form.Third Embodiment

[0133] In the present embodiment, differences from the first and second embodiments will be mainly described. In the present embodiment, the first region 21A also has the groove 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. However, the first region 21A has the groove 22 so that hydrophilicity of the second region 21B is higher than hydrophilicity of the first region 21A.

[0134] For example, as illustrated in FIG. 15, the depth of the groove 22 formed in the second region 21B is deeper than the depth of the groove 22 formed in the first region 21A. The depth of the groove 22 formed in the first region 21A is, for example, 10 μm or more, and the depth of the groove 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these depths are an example, and may be set to other depths.

[0135] Alternatively, as illustrated in FIG. 16, the groove width of the groove 22 formed in the second region 21B is smaller than the groove width of the groove 22 formed in the first region 21A. The groove width of the groove 22 formed in the first region 21A is, for example, 10 μm or more, and the groove width of the groove 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these groove widths are an example, and other groove widths may be set.

[0136] 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 may be densely provided, and the grooves 22 in the first region 21A may be coarsely provided. Alternatively, the groove pitch of the grooves 22 may be made constant by adjusting the depth and the groove width of the groove 22.

[0137] Alternatively, as illustrated in FIG. 17, the number of the grooves 22 formed in the second region 21B is larger than the number of the grooves 22 formed in the first region 21A. The number of grooves is compared, for example, by the number of grooves in a certain area.

[0138] For example, the number of the grooves 22 formed in the second region 21B is 2 to 10 times the number of the 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 provided, and the grooves 22 in the first region 21A are coarsely provided. The number of the grooves 22 is an example, and other numbers may be set.

[0139] The groove depth, the groove width, and the number of the grooves 22 of the first array group 10A and the groove depth, the groove width, and the number of the grooves 22 of the second array group 10B may be the same or different. In addition, the groove depth, the groove width, and the number in a certain area of the grooves 22 of the second region 21B are not necessarily uniform, and may be different in the second region 21B. For example, in the second region 21B, the groove depths of the grooves 22 may be gradually smaller toward the first region 21A. Similarly, in the first region 21A, the groove depth, the groove width, and the number in a certain area of the grooves 22 may not be uniform.

[0140] As described above, in order to cause a difference in hydrophilicity between the first region 21A and the second region 21B, the depth, the groove width, and the number of the grooves 22 can be adjusted. Of course, the depth, the groove width, and the number illustrated in FIGS. 15 to 17 may be combined. Further, the depth, the groove width, and the number of the grooves 22 can also be applied to the groove 22 illustrated in FIGS. 11 to 14 of the second embodiment.

[0141] The present disclosure is not limited to the above-described embodiments, and can be variously modified as follows without departing from the gist of the present disclosure. For example, the above-described embodiments may be appropriately combined, or the above-described embodiments may be variously modified.

[0142] (1) In each of the embodiments described above, the heat exchanger 1 is applied to the evaporator, but the present invention is not limited to this aspect. For example, the present invention can also be applied to other heat exchangers such as a cooler core in which condensed water is generated.

[0143] (2) The heat exchanger 1 has a configuration in which the ends of the plurality of tubes 10 are brazed and layered and provided with respect to the first tank 30 and the second tank 40, but the present invention is not limited to this aspect.

[0144] The heat exchanger 1 can adopt various aspects as long as the heat exchanger 1 includes a core portion configured by layering and disposing a plurality of tubes and a pair of tanks provided at the ends of the tubes. For example, the present invention can also be applied to a configuration in which a tube is formed by joining a pair of facing plate members having a recess having a predetermined shape, and the pairs of plate members are layered and provided to form a heat exchanger having a pair of tanks and a plurality of tubes.

[0145] (3) The second region 21B may be provided adjacent to at least one of the partial region 12A of the joint portion 12 at one of the adjacent tubes 10 and the partial region 12A of the joint portion 12 at the other of the adjacent tubes 10, and need not be provided adjacent to both.

[0146] (4) The shape of the first region 21A and the second region 21B taken along arrow III is not limited to the quadrangular shape, but may be another shape such as a trapezoidal shape. The first region 21A and the second region 21B are not limited to a quadrangular shape or the like, and may have any shape including a curve. Further, the boundary line between the first region 21A and the second region 21B is not limited to a straight line, but may be a curved line.

[0147] (5) Between adjacent tubes 10, the second region 21B of the outer surface 21 of the fin 20 need not be provided to be sandwiched between the two first regions 21A. For example, one first region 21A and one second region 21B of the outer surface 21 of the fin 20 may be provided between adjacent tubes 10. Alternatively, the first region 21A and the second region 21B may be alternately provided in the air passage direction AF. In this case, the number of the first regions 21A and the number of the second regions 21B may be the same or different. For example, the two first regions 21A and the two second regions 21B may be alternately provided, or the second regions 21B may be provided between the three first regions 21A.

[0148] (6) The groove 22 need not be linearly laid out. The groove 22 may be laid out in a curved shape, for example. Alternatively, the groove 22 may be laid out including a straight portion and a curved portion.

[0149] (7) The tube 10 need not be a flat tube having a flat cross-sectional shape, but a tube having another shape. For example, the tube wall face 11 may have a curved shape so that the tube 10 has a cylindrical shape. In this case, for example, the groove 22 is formed so as to be inclined with respect to the tangent of the tube wall face 11 with the partial region 12A of the joint portion 12 as the starting point 12B. Alternatively, the groove 22 may be formed so as to be inclined with respect to the normal line of the tube 10 with the partial region 12A of the joint portion 12 as the starting point 12B.

[0150] (8) The region of the outer surface 21 of the fin 20, the region having the groove 22, is not limited to the curved portion 24A, the flat portion 24G, and the louver body portion 24D. For example, each of the one louver end 24E and the other louver end 24F may have the groove 22.

[0151] (9) The outer surface 21 of the fin 20 may be subjected to a surface treatment for improving hydrophilicity. For example, the entire fin 20 is coated with a hydrophilic resin having high water resistance such as polyvinyl alcohol.

[0152] (10) The fin 20 need not have the louver 24C.

[0153] Although the present disclosure is described in accordance with examples, it is understood that the present disclosure is not limited to the examples and structures. The present disclosure also includes various modification examples and modifications within an equivalent range. In addition, various combinations and modes, and other combinations and modes including only one element, more elements, or less elements therein are within the scope and idea of the present disclosure.

[0154] The technical features of the heat exchanger disclosed herein are as follows.(Item 1)

[0155] A heat exchanger includes: a tube (10) configured to cause first fluid to flow therethrough; and a fin (20) formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid. An outer surface (21) of the fin includes a first region (21A) and a second region (21B), the second region having higher hydrophilicity than the first region. The second region has a groove (22) configured to improve hydrophilicity of the outer surface. The second region is adjacent to a partial region (12A) of a joint portion (12), which is between the tube and the fin.(Item 2)

[0156] The heat exchanger according to item 1, in which the tube extends in a tube extending direction (DRt), a plurality of the tubes, which are arranged in a tube array direction (DRst) that intersects the tube extending direction, constitutes an array group (10A, 10B), the fin is provided between adjacent tubes constituting the array group, and the first region and the second region are arranged, such that the first region, the second region, and the first region are arranged in this order along a second fluid flow direction, which intersects the tube extending direction and the tube array direction, in a fin body region (21C, 21D) of the outer surface of the fin, the fin body region being located between the adjacent tubes.(Item 3)

[0157] The heat exchanger according to item 2, in which the array group includes a first array group (10A) and a second array group (10B) arranged in the second fluid flow direction, and the fin is arranged across the first array group and the second array group. The first region and the second region are provided, such that in a first fin body region (21C) of the outer surface of the fin, which is located between the adjacent tubes constituting the first array group, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction, and in a second fin body region (21D) of the outer surface of the fin, which is located between the adjacent tubes constituting the second array group, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction.(Item 4)

[0158] The heat exchanger according to any one of items 1 to 3, in which the groove is formed from a starting point (12B), which is in the partial region of the joint portion, along a direction away from the joint portion.(Item 5)

[0159] The heat exchanger according to any one of items 1 to 4, in which the first region has the groove configured to improve hydrophilicity of the outer surface of the fin, and a depth of the groove formed in the second region is larger than a depth of the groove formed in the first region.(Item 6)

[0160] The heat exchanger according to any one of items 1 to 5, in which the first region has the groove configured to improve hydrophilicity of the outer surface of the fin, and a groove width of the groove formed in the second region is smaller than a groove width of the groove formed in the first region.(Item 7)

[0161] The heat exchanger according to any one of items 1 to 6, in which the first region has the groove configured to improve hydrophilicity of the outer surface of the fin, and a number of the grooves formed in the second region is larger than a number of the grooves formed in the first region.

Examples

first embodiment

[0036]The heat exchanger according to the present embodiment is used, for example, as an evaporator constituting part of a refrigeration cycle that performs air conditioning in a vehicle interior of a vehicle. The refrigeration cycle includes, for example, a compressor, a condenser, an expansion valve, and an evaporator. The evaporator is provided inside an air conditioning case through which blown air to be blown into the vehicle interior flows.

[0037]Therefore, the evaporator exchanges heat between the low-pressure refrigerant as the first fluid in 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 causing the low-pressure refrigerant to absorb heat from the blown air. That is, the evaporator is a cooling heat exchanger for cooling air by latent heat of vaporization of the refrigerant.

[0038]Hereinafter, the first embodiment will be described with reference to FIGS. 1...

second embodiment

[0123]In the present embodiment, differences from the first embodiment will be mainly described. The present embodiment is different from the first embodiment in the form of the groove 22. FIGS. 11 to 14 illustrate a groove pattern of the grooves 22 of the first array group 10A.

[0124]For example, as illustrated in FIG. 11, the groove 22 is formed along the tube array direction DRst and is formed along the air passage direction AF. That is, the groove 22 extends in two directions. The groove 22 along the tube array direction DRst and the groove 22 along the air passage direction AF intersect at a right angle. Therefore, the groove 22 is formed in a lattice shape. Accordingly, more condensed water Wc can be drawn into the second region 21B by the groove 22.

[0125]The groove 22 in the two directions does not necessarily intersect at a right angle, and may intersect at an angle other than the right angle. The groove 22 is not limited to being formed in two directions, but may be formed i...

third embodiment

[0133]In the present embodiment, differences from the first and second embodiments will be mainly described. In the present embodiment, the first region 21A also has the groove 22 for improving the hydrophilicity of the outer surface 21 of the fin 20. However, the first region 21A has the groove 22 so that hydrophilicity of the second region 21B is higher than hydrophilicity of the first region 21A.

[0134]For example, as illustrated in FIG. 15, the depth of the groove 22 formed in the second region 21B is deeper than the depth of the groove 22 formed in the first region 21A. The depth of the groove 22 formed in the first region 21A is, for example, 10 μm or more, and the depth of the groove 22 formed in the second region 21B is, for example, 20 μm to 30 μm. Of course, these depths are an example, and may be set to other depths.

[0135]Alternatively, as illustrated in FIG. 16, the groove width of the groove 22 formed in the second region 21B is smaller than the groove width of the groov...

Claims

1. A heat exchanger comprising:a tube configured to cause first fluid to flow therethrough; anda fin formed by bending a plate-shaped member and configured to promote heat exchange between second fluid, which flows outside the tube, and the first fluid, whereinan outer surface of the fin includes a first region and a second region, the second region having higher hydrophilicity than the first region,the second region has a groove configured to improve hydrophilicity of the outer surface, andthe second region is adjacent to a partial region of a joint portion, which is between the tube and the fin.

2. The heat exchanger according to claim 1, whereinthe tube extends in a tube extending direction,a plurality of the tubes, which are arranged in a tube array direction that intersects the tube extending direction, constitutes an array group,the fin is provided between adjacent tubes constituting the array group, andthe first region and the second region are arranged, such that the first region, the second region, and the first region are arranged in this order along a second fluid flow direction, which intersects the tube extending direction and the tube array direction, in a fin body region of the outer surface of the fin, the fin body region being located between the adjacent tubes.

3. The heat exchanger according to claim 2, whereinthe array group includes a first array group and a second array group arranged in the second fluid flow direction, andthe fin is arranged across the first array group and the second array group,the first region and the second region are provided, such thatin a first fin body region of the outer surface of the fin, which is located between the adjacent tubes constituting the first array group, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction, andin a second fin body region of the outer surface of the fin, which is located between the adjacent tubes constituting the second array group, the first region, the second region, and the first region are arranged in this order along the second fluid flow direction.

4. The heat exchanger according to claim 1, whereinthe groove is formed from a starting point, which is in the partial region of the joint portion, along a direction away from the joint portion.

5. The heat exchanger according to claim 1, whereinthe first region has the groove configured to improve hydrophilicity of the outer surface of the fin, anda depth of the groove formed in the second region is larger than a depth of the groove formed in the first region.

6. The heat exchanger according to claim 1, whereinthe first region has the groove configured to improve hydrophilicity of the outer surface of the fin, anda groove width of the groove formed in the second region is smaller than a groove width of the groove formed in the first region.

7. The heat exchanger according to claim 1, whereinthe first region has the groove configured to improve hydrophilicity of the outer surface of the fin, anda number of the grooves formed in the second region is larger than a number of the grooves formed in the first region.

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