Heat exchanger and refrigeration cycle device

Abstract

The present application provides a heat exchanger capable of draining liquid droplets attached to a heat conducting tube well, and a refrigeration cycle device provided with the heat exchanger. The heat exchanger of one embodiment is provided with a flat heat conducting tube and a fin portion in contact with the heat conducting tube. The heat conducting tube has a first end portion and a second end portion in the width direction, and a plurality of refrigerant flow paths arranged in the width direction between the first end portion and the second end portion. Furthermore, the heat conducting tube includes an upper surface parallel to the width direction, a lower surface parallel to the upper surface, and a first curved surface located between the upper surface and the first end portion in the width direction and above the lower surface in the thickness direction orthogonal to the upper surface and the lower surface. The distance between the first curved surface and the lower surface decreases as it approaches the first end portion.

Description

[0001] This application is based on Japanese Patent Application No. 2021-050345 (Filing date: March 24, 2021) and claims priority thereto. The entire contents of the application are incorporated herein by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to a heat exchanger and a refrigeration cycle device. BACKGROUND

[0003] Conventionally, a heat exchanger is known that includes a plurality of flat heat conducting pipes having refrigerant flow paths inside and a plurality of fins in contact with the heat conducting pipes. Such a heat exchanger is used, for example, in a refrigeration cycle device such as an air conditioner.

[0004] In a case where the heat exchanger functions as an evaporator, liquid droplets (water droplets) generated due to condensation or the like can adhere to the surface of the heat conducting pipe. In a case where the liquid droplets are not properly drained from the surface of the heat conducting pipe, the heat exchange performance can be reduced. SUMMARY

[0005] An object of the present application is to provide a heat exchanger capable of properly draining liquid droplets adhering to a heat conducting pipe and a refrigeration cycle device including the heat exchanger.

[0006] The heat exchanger of the embodiment includes a flat heat conducting pipe and a fin in contact with the heat conducting pipe. The heat conducting pipe has a first end portion and a second end portion in a width direction, and a plurality of refrigerant flow paths arranged in the width direction between the first end portion and the second end portion. The heat conducting pipe includes an upper surface parallel to the width direction, a lower surface parallel to the upper surface, and a first curved surface located between the upper surface and the first end portion in the width direction and located above the lower surface in a thickness direction orthogonal to the upper surface and the lower surface. The distance between the first curved surface and the lower surface decreases as it approaches the first end portion.

[0007] The heat exchanger of another aspect of the embodiment includes a flat heat conducting pipe and a fin in contact with the heat conducting pipe. The heat conducting pipe has a first end portion and a second end portion in a width direction, and a plurality of refrigerant flow paths arranged in the width direction between the first end portion and the second end portion. The heat conducting pipe includes a flat portion having a constant thickness, a first convex portion located between the flat portion and the first end portion and having a first width in the width direction and a decreasing thickness as it approaches the first end portion, and a second convex portion located between the flat portion and the second end portion and having a second width in the width direction and a decreasing thickness as it approaches the second end portion. The first width is greater than the second width.

[0008] The refrigeration cycle device of the embodiment is provided with the heat exchanger described above, and a fan that generates an airflow that passes through the heat exchanger. The first end portion is located at a position that is on the downstream side of the airflow than the second end portion.

[0009] According to the embodiment, it is possible to provide a heat exchanger that can drain liquid droplets attached to a heat transfer tube well, and a refrigeration cycle device provided with the heat exchanger. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a diagram that shows the schematic configuration of the refrigeration cycle device of the first embodiment.

[0011] Figure 2 is a schematic plan view of the heat exchanger of the first embodiment.

[0012] Figure 3 is a schematic cross-sectional view of the heat exchanger along the III-III line in Figure 2

[0013] Figure 4 is a cross-sectional view that enlarges the heat transfer tube shown in Figure 3

[0014] Figure 5 is a schematic cross-sectional view of the heat transfer tube of the comparative example.

[0015] Figure 6 is a schematic cross-sectional view for explaining the effect of the heat transfer tube of the first embodiment.

[0016] Figure 7 is a schematic cross-sectional view of the heat exchanger of the second embodiment.

[0017] Figure 8 is a schematic cross-sectional view of the heat exchanger of the third embodiment.

[0018] Figure 9 is a schematic cross-sectional view of the heat exchanger of the fourth embodiment.

[0019] Figure 10 is a schematic cross-sectional view of the heat exchanger of the fifth embodiment.

[0020] Figure 11 is a schematic cross-sectional view of the heat transfer tube of the sixth embodiment. DETAILED DESCRIPTION

[0021] ​​Several embodiments will be described with reference to the drawings. In each of the embodiments, as one example of a refrigeration cycle device provided with a heat exchanger, an air conditioner capable of performing a cooling operation and a heating operation is disclosed. However, the configurations disclosed in each of the embodiments can also be applied to refrigeration cycle devices other than air conditioners. Furthermore, the heat exchanger disclosed in each of the embodiments can also be utilized in devices other than refrigeration cycle devices.

[0022] [First Embodiment]

[0023] Figure 1 is a diagram showing the schematic configuration of a refrigeration cycle device 1 of the first embodiment. The refrigeration cycle device 1 is provided with a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, an indoor heat exchanger 6, and refrigerant piping 7 connecting these elements. Furthermore, the refrigeration cycle device 1 is provided with an outdoor fan 8 that sends air to the outdoor heat exchanger 4, and an indoor fan 9 that sends air to the indoor heat exchanger 6.

[0024] The compressor 2 is provided with a compressor main body 2a and an accumulator 2b. The accumulator 2b separates the refrigerant supplied via the refrigerant piping 7 into gas and liquid, and supplies the gas refrigerant to the compressor main body 2a. The compressor main body 2a compresses the gas refrigerant supplied from the accumulator 2b to generate high-temperature, high-pressure gas refrigerant.

[0025] In such a refrigeration cycle device 1, by changing the flow of the refrigerant using the four-way valve 3, it is possible to switch between a cooling operation, a heating operation, and the like. In the example shown in Figure 1 , the solid-line arrow indicates the flow of the refrigerant in the cooling operation, and the broken-line arrow indicates the flow of the refrigerant in the heating operation.

[0026] For example, in the cooling operation, the refrigerant flows in the order of the compressor 2, the four-way valve 3, the outdoor heat exchanger 4, the expansion valve 5, and the indoor heat exchanger 6. At this time, the outdoor heat exchanger 4 functions as a condenser, and the indoor heat exchanger 6 functions as an evaporator, whereby the room is cooled.

[0027] On the other hand, in the heating operation, the flow path of the four-way valve 3 is switched as shown by the broken line, and the refrigerant flows in the order of the compressor 2, the four-way valve 3, the indoor heat exchanger 6, the expansion valve 5, and the outdoor heat exchanger 4. At this time, the indoor heat exchanger 6 functions as a condenser, and the outdoor heat exchanger 4 functions as an evaporator, whereby the room is heated.

[0028] Figure 2 is a schematic plan view of a heat exchanger 100 of the present embodiment. This heat exchanger 100 can be utilized in Figure 1 the outdoor heat exchanger 4 and the indoor heat exchanger 6 shown in

[0029] The heat exchanger 100 includes a first manifold 10 and a second manifold 20. Both the first manifold 10 and the second manifold 20 are long strips of pipe, spaced apart and arranged in parallel.

[0030] Both ends of the first manifold 10 are closed by end caps 11 and 12. Furthermore, the first manifold 10 has a first connector 13 for connecting to the refrigerant piping 7 of the refrigeration cycle unit 1.

[0031] Similarly, both ends of the second manifold 20 are closed by end caps 21 and 22. Furthermore, the second manifold 20 has a second connector 23 for connection to the refrigerant piping 7.

[0032] The heat exchanger 100 further includes a plurality of heat pipes 30 and a plurality of fins 40 (plates). The plurality of heat pipes 30 are spaced apart and arranged parallel to each other in a first arrangement direction D1. The plurality of fins 40 are spaced apart and arranged parallel to each other in a second arrangement direction D2.

[0033] exist Figure 2 In this example, the spacing between the heat pipes 30 in the first arrangement direction D1 is greater than the spacing between the fins 40 in the second arrangement direction D2. As an example, the interval (spacing) between adjacent fins 40 is approximately 1.5 mm.

[0034] One end of each heat pipe 30 in the second arrangement direction D2 is connected to the first manifold 10. Furthermore, the other end of each heat pipe 30 in the second arrangement direction D2 is connected to the second manifold 20. For example, when refrigerant is supplied to the heat exchanger 100 via the first connector 13, the refrigerant is diverted from the first manifold 10 to each heat pipe 30, merges in the second manifold 20, and is discharged from the heat exchanger 100 via the second connector 23. Similarly, when refrigerant is supplied to the heat exchanger 100 via the second connector 23, the refrigerant is diverted from the second manifold 20 to each heat pipe 30, merges in the first manifold 10, and is discharged from the heat exchanger 100 via the first connector 13.

[0035] The outdoor heat exchanger 4 and indoor heat exchanger 6 can also be constructed by connecting multiple heat exchangers 100 with interconnected flow paths. In this case, either the first connector 13 or the second connector 23 can also be used to connect the flow paths of the heat exchangers 100 to each other.

[0036] The first manifold 10, the second manifold 20, each heat pipe 30, and each fin 40 are formed of a metallic material. For example, aluminum or an aluminum alloy can be used as this metallic material. The first manifold 10, the second manifold 20, each heat pipe 30, and each fin 40 are joined together, for example, by brazing.

[0037] Figure 3 It is along Figure 2a cross-sectional view of the heat exchanger 100 taken along the III-III line in FIG. 1. Specifically, Figure 3 is shown in FIG. 2. FIG. 2 is a cross-sectional view of the heat exchanger 100 taken along the III-III line in FIG. 1. Specifically, Figure 2 is shown in FIG. 2. FIG. 2 is a cross-sectional view of the heat exchanger 100 taken along the III-III line in FIG. 1. Specifically,

[0038] As shown in FIG. 1, a width direction WD of the heat transfer tube 30 and a thickness direction TD of the heat transfer tube 30 are defined. The heat transfer tube 30 is long in the width direction WD. Figure 3 Figure 2 As shown in FIG. 1, a width direction WD of the heat transfer tube 30 and a thickness direction TD of the heat transfer tube 30 are defined. The heat transfer tube 30 is long in the width direction WD.

[0039] In the present embodiment, the thickness direction TD coincides with the first arrangement direction Dl. Further, in a state where the heat exchanger 100 is assembled to an outdoor unit as the outdoor heat exchanger 4, or in a state where the heat exchanger 100 is assembled to an indoor unit as the indoor heat exchanger 6, the first arrangement direction Dl is parallel to the gravitational direction GD.

[0040] The heat exchanger 100 is exposed to an airflow in a supply direction SD. The airflow is generated by the outdoor fan 8 in a case where the heat exchanger 100 is utilized as the outdoor heat exchanger 4, or is generated by the indoor fan 9 in a case where the heat exchanger 100 is utilized as the indoor heat exchanger 6.

[0041] In the present embodiment, the supply direction SD coincides with the width direction WD. In Figure 3 In FIG. 1, a symbol of USM is given to an upstream side (primary side) of the heat exchanger 100 with respect to the supply direction SD, and a symbol of DSM is given to a downstream side (secondary side).

[0042] The heat transfer tube 30 has a first end portion 31 and a second end portion 32 in the width direction WD. The first end portion 31 is a portion of the heat transfer tube 30 located at the most downstream side DSM. The second end portion 32 is a portion of the heat transfer tube 30 located at the most upstream side USM.

[0043] The heat transfer tube 30 has a plurality of refrigerant flow paths 33 that communicate with flow paths in the first header 10 and flow paths in the second header 20 as shown in FIG. 1. These refrigerant flow paths 33 are arranged in the width direction WD between the first end portion 31 and the second end portion 32. Figure 2

[0044] ​​The fin 40 has a plurality of fins 41 respectively disposed between adjacent heat pipes 30 in the first arrangement direction D1, and a connecting portion 42 (communication portion) connecting these fins 41. In this embodiment, the connecting portion 42 is located at a position downstream of each heat pipe 30 on the downstream side DSM. That is, the connecting portion 42 is connected to the end of the downstream side DSM of each fin 41. The connecting portion 42 is formed to communicate between the two ends of the fin 40 in the first arrangement direction D1. In this embodiment, each fin 41 and the connecting portion 42 communicating in the first arrangement direction D1 are integrally formed.

[0045] Fins 41 arranged between adjacent heat pipes 30 are in contact with both sides of these heat pipes 30. A slit 43 is formed between adjacent fins. The slit 43 opens at the end edge of the upstream side USM of the fin 40. The heat pipe 30 is inserted into the slit 43.

[0046] The slit 43 has a widening portion 43a located on the upstream side USM. The width of the widening portion 43a in the first arrangement direction D1 decreases as it approaches the downstream side DSM. By providing the widening portion 43a, the heat pipe 30 can be smoothly inserted relative to the slit 43 during the manufacture of the heat exchanger 100. The portion 43b near the end of the downstream side DSM of the slit 43 has a shape that fits into the portion near the first end 31 of the heat pipe 30 (the first curved surface 36 described later).

[0047] Figure 4 It is Figure 3 The diagram shows an enlarged cross-sectional view of the heat pipe 30. Multiple partitions 33a are disposed inside the heat pipe 30. These partitions 33a divide the internal space of the heat pipe 30 into multiple refrigerant flow paths 33.

[0048] The heat pipe 30 has an upper surface 34 and a lower surface 35. The upper surface 34 and the lower surface 35 are parallel planes. Furthermore, the upper surface 34 and the lower surface 35 are parallel to the width direction WD and orthogonal to the thickness direction TD.

[0049] The upper surface 34 has a width Wa in the width direction WD. The lower surface 35 has a width Wb in the width direction WD. In this embodiment, the width Wb is greater than the width Wa (Wa < Wb). The upper surface 34 overlaps the lower surface 35 entirely in the thickness direction TD.

[0050] The heat pipe 30 further has a first curved surface 36 and a second curved surface 37 connecting the upper surface 34 and the lower surface 35. The first curved surface 36 can also be referred to as the side surface of the downstream side DSM of the heat pipe 30. The second curved surface 37 can also be referred to as the side surface of the upstream side USM of the heat pipe 30.

[0051] The first curved surface 36 is located between the upper surface 34 and the first end portion 31 in the width direction WD. The second curved surface 37 is located between the upper surface 34 and the lower surface 35 and the second end portion 32 in the width direction WD.

[0052] The first curved surface 36 has a width W1 (first width) in the width direction WD. The second curved surface 37 has a width W2 (second width) in the width direction WD. In the present embodiment, the width W1 is larger than the width W2 (W1 > W2). As one example, the width W1 is 1.5 times or more, preferably 2 times or more, the width W2.

[0053] The first curved surface 36 entirely overlaps the lower surface 35 in the thickness direction TD. On the other hand, the second curved surface 37 does not overlap either the upper surface 34 or the lower surface 35 in the thickness direction TD. In Figure 4 In the example, no partition wall 33a is disposed between the first curved surface 36 and the lower surface 35. As another example, a partition wall 33a can be disposed between the first curved surface 36 and the lower surface 35.

[0054] The first curved surface 36 has a shape in which the distance between the thickness direction TD and the lower surface 35 decreases as it approaches the first end portion 31. In the present embodiment, the first curved surface 36 is composed of a plurality of portions having different curvatures. In Figure 4 In the example, the first curved surface 36 includes a first portion 36a having a radius of curvature R1a, a second portion 36b having a radius of curvature R1b, and a third portion 36c having a radius of curvature R1c.

[0055] The first portion 36a connects the upper surface 34 and the second portion 36b. The second portion 36b connects the first portion 36a and the third portion 36c. The third portion 36c connects the second portion 36b and the lower surface 35. The point in the third portion 36c that protrudes most toward the downstream side DSM corresponds to the first end portion 31 of the heat pipe 30. That is, the first curved surface 36 includes the first end portion 31.

[0056] The center of curvature O1a of the first portion 36a is located at a position lower (lower surface 35 side) than the first portion 36a. The center of curvature O1b of the second portion 36b is located at a position higher than the second portion 36b. That is, the first portion 36a is convex toward the outside of the heat pipe 30. Further, the second portion 36b is concave toward the inside of the heat pipe 30. The line segment connecting the centers of curvature O1a and O1b intersects the first curved surface 36. The region of the first curved surface 36 composed of the first portion 36a and the second portion 36b is curved in a manner in which the cross-sectional shape is S-shaped. The radii of curvature R1a and R1b are, for example, the same, but can be different from each other.

[0057] The radius of curvature R1c of part 36c is preferably sufficiently small compared to the radii of curvature R1a and R1b. Figure 4 In the example, near the third part 36c, the inner surfaces 38 of the heat pipes 30 are in contact with each other. This allows the radius of curvature R1c of the third part 36c to be minimized.

[0058] exist Figure 4 In the example, the second surface 37 is a semicircle with a constant curvature. The radius of curvature R2 of the second surface 37 is, for example, equal to the radius of curvature R1a. That is, the radius of curvature R1c of the third part 36c is sufficiently small compared to the radius of curvature R2 (R1c < R2). The point that protrudes most upstream of the USM in the second surface 37 corresponds to the second end 32. That is, the second surface 37 includes the second end 32.

[0059] When the heat pipe 30 having the above-described upper surface 34, lower surface 35, first curved surface 36 and second curved surface 37 is described from other viewpoints, the heat pipe 30 has: a flat portion 30A having a constant thickness T; a first protrusion 30B protruding from the flat portion 30A toward the downstream side DSM; and a second protrusion 30C protruding from the flat portion 30A toward the upstream side USM.

[0060] The flat portion 30A is a portion of its outer surface formed by a portion of the upper surface 34 and the lower surface 35, and has the same width Wa as the upper surface 34. The first convex portion 30B is a portion of its outer surface formed by a portion of the first curved surface 36 and the lower surface 35, and has the same width W1 as the first curved surface 36. The second convex portion 30C is a portion of its outer surface formed by a second curved surface 37, and has the same width W2 as the second curved surface 37.

[0061] The thickness of the first protrusion 30B decreases as it approaches the first end 31. The thickness of the second protrusion 30C decreases as it approaches the second end 32. The first protrusion 30B has a sharper shape compared to the second protrusion 30C.

[0062] Compared to the center C in the thickness direction TD of the heat pipe 30, the front end 31 of the first protrusion 30B is located on the lower surface 35 side. On the other hand, the front end 32 of the second protrusion 30C is located at the same position as the center C.

[0063] Next, an example of the effect achieved by this embodiment will be described.

[0064] Figure 5 This is a schematic cross-sectional view of the heat pipe 30X of this embodiment and comparative example. Figure 6 This is a schematic cross-sectional view used to illustrate the effect of the heat pipe 30 in this embodiment.

[0065] Figure 5The heat pipe 30X shown has a first end 31X on the downstream side DSM, a second end 32X on the upstream side USM, an upper surface 34X, a lower surface 35X, a first curved surface 36X including the first end 31X, and a second curved surface 37X including the second end 32X. The shape of the second curved surface 37X is similar to... Figure 4 The second curved surface 37 of the heat pipe 30 shown has the same shape. In addition, the first curved surface 37X also has the same shape as the second curved surface 37X.

[0066] When the heat exchanger equipped with the heat pipe 30X functions as an evaporator, droplets 200 generated due to condensation or other reasons may sometimes adhere to the upper surface 34X of the heat pipe 30X. The droplets 200 are carried downstream to the DSM by the airflow flowing along the air supply direction SD.

[0067] When the first curved surface 36X has the shape shown in the figure, the airflow velocity around the first end 31X decreases. Furthermore, the droplets 200 flow downwards along the first curved surface 36X and are difficult to separate from the first end 31X. Therefore, the droplets 200 remain on the surface of the heat pipe 30X for a long time, causing frost formation. If frost forms, the heat exchange efficiency decreases.

[0068] on the other hand, Figure 6 The heat pipe 30 of this embodiment shown has a lower surface 35 near the first end 31 and a first curved surface 36 located above the thickness direction TD. Furthermore, the distance between the first curved surface 36 and the lower surface 35 decreases as it approaches the first end 31. With this shape, the flat lower surface 35 reaches the vicinity of the first end 31, and the first end 31 is pointed, so droplets 200 flowing to the first end 31 do not flow below the heat pipe 30 but are easily blown away by the airflow.

[0069] If used Figure 4 As explained, the first curved surface 36 has a first portion 36a and a second portion 36b. The droplet 200 first flows smoothly downward due to the first portion 36a, and then flows towards the first end 31 in a manner along the airflow direction SD due to the second portion 36b. If the droplet 200 flows along the airflow direction SD near the first end 31, the droplet 200 is easily detached from the surface of the heat pipe 30 due to the pointed first end 31.

[0070] In this embodiment, the fin 40 has a connecting portion 42 that connects each fin 41. Droplets adhering to the fin 40 flow downward along the connecting portion 42. In particular, in this embodiment, the connecting portion 42 is provided on the first end 31 side (downstream side DSM). In this case, droplets adhering to the surface of the heat pipe 30 near the first end 31 tend to flow along the connecting portion 42.

[0071] Thus, if the shape of the heat transfer tube 30 of the present embodiment, the drainability of the liquid droplets adhering to the upper surface 34 can be improved. Thereby, the heat exchange efficiency can be suppressed from decreasing, and the performance of the heat exchanger 100 can be improved. Further, the performance of the refrigeration cycle device 1 provided with the heat exchanger 100 as at least one of the outdoor heat exchanger 4 and the indoor heat exchanger 6 can be improved.

[0072] Hereinafter, other embodiments to which the heat exchanger 100 can be applied will be disclosed. The configurations not particularly mentioned in each of the embodiments are the same as those of the first embodiment. Further, the configurations disclosed in each of the embodiments can be appropriately combined.

[0073] [Second Embodiment]

[0074] Figure 7 is a schematic cross-sectional view of the heat exchanger 100 of the second embodiment. In the present embodiment, the heat exchanger 100 is inclined with respect to the air supply direction SD so that the airflow is blown to the lower surface 35 of the heat transfer tube 30.

[0075] Thereby, the width direction WD is not parallel to the air supply direction SD. Further, the first arrangement direction D1 is not parallel to the gravitational direction GD, and further, the thickness direction TD is not parallel to the gravitational direction GD. The first end portion 31 is located at a position lower than the second end portion 32 in the gravitational direction GD.

[0076] Thus, even in a case where the heat exchanger 100 is inclined with respect to the air supply direction SD, as long as the heat transfer tube 30 has the shape shown in Figure 4 , the liquid droplets adhering to the surface of the heat transfer tube 30 can be drained well.

[0077] [Third Embodiment]

[0078] Figure 8 is a schematic cross-sectional view of the heat exchanger 100 of the third embodiment. In the present embodiment, the heat transfer tube 30 is inclined with respect to the air supply direction SD so that the airflow is blown to the lower surface 35 of the heat transfer tube 30. Thereby, as in the second embodiment, the first end portion 31 is located at a position lower than the second end portion 32 in the gravitational direction GD.

[0079] Thus, in a case where the heat exchanger 100 is inclined with respect to the air supply direction SD, the liquid droplets adhering to the heat transfer tube 30 easily flow toward the first end portion 31. Thereby, the liquid droplets adhering to the surface of the heat transfer tube 30 can be drained more well.

[0080] [Fourth Embodiment]

[0081] Figure 9is a schematic cross-sectional view of the heat exchanger 100 of the fourth embodiment. In the present embodiment, the connecting portion 42 of the fin portion 40 is provided at the upstream side USM of each heat conducting pipe 30. That is, the connecting portion 42 is connected to the end portion of the upstream side USM of each fin 41.

[0082] The slit 43 is opened at the end edge of the downstream side DSM of the fin portion 40. In Figure 9 In the example shown in FIG. 10, the first end portion 31 of each heat conducting pipe 30 protrudes toward the downstream side DSM than each fin 41, but the present embodiment is not limited to this example.

[0083] Even in the case where the connecting portion 42 is provided at the upstream side USM of each heat conducting pipe 30 as in the present embodiment, as long as the heat conducting pipe 30 has Figure 4 the shape shown in FIG. 11, the liquid droplets adhering to the surface of the heat conducting pipe 30 can be drained well. Further, the liquid droplets adhering to the fin portion 40 flow downward along the connecting portion 42, and thus the drainability of the heat exchanger 100 is improved.

[0084] [5th Embodiment]

[0085] Figure 10 is a schematic cross-sectional view of the heat exchanger 100 of the fifth embodiment. In the present embodiment, the fin portion 40 has a first connecting portion 42a and a second connecting portion 42b.

[0086] The first connecting portion 42a is provided at the downstream side DSM of each heat conducting pipe 30. That is, the first connecting portion 42a is connected to the end portion of the downstream side DSM of each fin 41. The first connecting portion 42a extends between both ends of the fin portion 40 formed in the first arrangement direction Dl.

[0087] The second connecting portion 42b is provided at the upstream side USM of each heat conducting pipe 30. That is, the second connecting portion 42b is connected to the end portion of the upstream side USM of each fin 41. The second connecting portion 42b extends between both ends of the fin portion 40 formed in the first arrangement direction Dl.

[0088] In the example shown in FIG. 10, the first end portion 31 of each heat conducting pipe 30 protrudes toward the downstream side DSM than each fin 41, but the present embodiment is not limited to this example. Figure 10 In the example shown in FIG. 10, the first end portion 31 of each heat conducting pipe 30 protrudes toward the downstream side DSM than each fin 41, but the present embodiment is not limited to this example.

[0089] Even in the case where the first connecting portion 42a and the second connecting portion 42b are provided as in the present embodiment, as long as the heat conducting pipe 30 has Figure 4The illustrated shape enables good drainage of the liquid droplets adhering to the surface of the heat transfer tube 30. Further, on the downstream side DSM of each heat transfer tube 30, the liquid droplets flow downward along the first connecting portion 42a, and on the upstream side USM of each heat transfer tube 30, the liquid droplets flow downward along the second connecting portion 42b, and thus the drainability of the heat exchanger 100 is improved.

[0090] At the time of air supply, the liquid droplets adhering to the heat transfer tube 30 flow toward the downstream side DSM. Therefore, as in the example of Figure 10 , the liquid droplets are well drained along the first connecting portion 42a.

[0091] Further, in the case where the first connecting portion 42a and the second connecting portion 42b are provided to the fin portion 40, the fin portion 40 and the heat exchanger 100 can be upsized. In this regard, in the example of Figure 10 , since the width of the second connecting portion 42b is small, the upsizing of the fin portion 40 and the heat exchanger 100 can be suppressed.

[0092] [6th Embodiment]

[0093] Figure 11 is a schematic cross-sectional view of the heat transfer tube 30 of the 6th embodiment. This heat transfer tube 30 is different from the heat transfer tube 30 of the example of Figure 4 in the shape of the first curved surface 36.

[0094] That is, in the example of Figure 11 , the first curved surface 36 is curved with a constant curvature between the upper surface 34 and the first end portion 31. Further, the first curved surface 36 is located above the lower surface 35 in the thickness direction TD as in the example of Figure 4 . Further, the width W1 of the first curved surface 36 (the first convex portion 30B) is larger than the width W2 of the second curved surface 37 (the second convex portion 30C).

[0095] Even in the case where the heat transfer tube 30 has the shape of the present embodiment, the drainability of the liquid droplets adhering to the upper surface 34 can be improved as in the 1st embodiment.

[0096] Further, the heat transfer tube 30 of the present embodiment can be applied to any one of the heat exchangers 100 of the above-described respective embodiments. The shape of the heat transfer tube 30 is not limited to that illustrated in Figure 4 and Figure 11 . For example, the shape of the first curved surface 36 (the first convex portion 30B) can be deformed into other various modes.

[0097] In the example of Figure 4 and Figure 11In the heat conducting pipe 30 shown, a curved surface identical to the first curved surface 36 is provided between the lower surface 35 and the first end portion 31. Further, a curved surface identical to the first curved surface 36 can be provided between the upper surface 34 and the second end portion 32 and between the lower surface 35 and the second end portion 32.

[0098] In each embodiment, a heat exchanger 100 provided with a plate-shaped fin portion 40 is disclosed. The heat conducting pipe 30 in each embodiment can be applied, for example, to a heat exchanger provided with a wave-shaped corrugated fin portion or other types of heat exchangers.

[0099] Several embodiments of the present application have been described, but these embodiments are presented as examples and are not intended to limit the scope of the application. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made within the scope of the gist of the application. These embodiments and modifications thereof are included in the scope, gist, and range of the application described in the claims and equivalents thereof.

Claims

1. A heat exchanger, comprising: a plurality of heat conducting tubes; and a plurality of fins arranged in parallel at intervals, each of the plurality of fins being arranged to contact the plurality of heat conducting tubes, wherein each of the plurality of heat conducting tubes comprises: a first end portion; a second end portion; an upper surface parallel to a width direction; a lower surface parallel to the upper surface; and a first curved surface located above the lower surface in a thickness direction orthogonal to the upper surface and the lower surface, the first curved surface being located between the upper surface and the first end portion in the width direction, wherein the first curved surface comprises: a first portion convex toward an outer side of the heat conducting tube; a second portion concave toward an inner side of the heat conducting tube, the second portion being located between the first portion and the first end portion in the width direction; and a third portion connecting the second portion and the lower surface, wherein a distance between the first curved surface and the lower surface decreases as the first end portion is approached, and wherein a radius of curvature of the third portion is smaller than radii of curvature of the first portion and the second portion. A flat heat pipe has a first end portion and a second end portion in a width direction, and a plurality of refrigerant flow paths arranged in the width direction between the first end portion and the second end portion.

2. The heat exchanger according to claim 1, wherein: the heat conducting tube further has a second curved surface connecting the upper surface and the lower surface, the second curved surface including the second end portion, wherein the first curved surface has a first width in the width direction, wherein the second curved surface has a second width in the width direction, and wherein the first width is larger than the second width.

3. The heat exchanger according to claim 1, wherein: the first end portion is located lower than the second end portion in a gravitational direction.

4. The heat exchanger according to claim 1, wherein: the plurality of heat conducting tubes are arranged in parallel at intervals, wherein the plurality of fins each have: a plurality of fin portions located between adjacent ones of the plurality of heat conducting tubes; and a communication portion formed by ends of the plurality of fin portions in the width direction being communicated in an arrangement direction of the plurality of heat conducting tubes.

5. A refrigeration cycle device, comprising: the heat exchanger according to any one of claims 1 to 4; and a fan generating an airflow passing through the heat exchanger, wherein the first end portion is located on a downstream side of the airflow with respect to the second end portion. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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