JP2020153540A - Heat exchanger - Google Patents

Abstract

To provide a heat exchanger capable of improving heat exchange efficiency by suppressing retention of drain water at a lower side of corrugated fins.SOLUTION: In a heat exchanger including one or more tubes 30 having a plurality of straight portions 30a respectively extended in a vertical direction and arranged at intervals in a horizontal direction for circulating a first fluid, and a plurality of corrugated fins 40 respectively vertically extended between the straight portions 30a adjacent to each other in the one or more tubes, and exchanging heat between the first fluid circulated in the tubes 30 and a second fluid circulated outside of the tubes 30, a heat transfer enhancement piece 43 positioned in a prescribed range at a lower side of the corrugated fins 40, has an angle formed relative to an intermediate portion 42, larger than an angle formed by the intermediate portion 42 and the heat transfer enhancement piece 43 positioned outside of the prescribed range, in a range of 0 degree or more and 90 degrees or less.SELECTED DRAWING: Figure 4

Description

The present invention relates to a heat exchanger for exchanging heat between a refrigerant and air in, for example, a heat pump cycle used in an air conditioner for a vehicle.

Conventionally, as this type of heat exchanger, one or more tubes having a plurality of straight lines extending in the vertical direction and arranged at intervals in the horizontal direction, and straight lines adjacent to each other in the one or more tubes. It is known that a plurality of corrugated fins extending in the vertical direction between the portions are provided (see Patent Document 1 and Patent Document 2).

Further, this type of heat exchanger may be used as an evaporator of a heat pump cycle in which the refrigerant absorbs heat by exchanging heat between the refrigerant flowing inside the tube and the air flowing outside the tube. ..

Jikkai Sho 59-148972 Japanese Unexamined Patent Publication No. 2004-150710

By the way, in the heat exchanger used as the evaporator of the heat pump cycle, drain water such as molten water generated by defrosting operation and condensed water generated by dew condensation adheres to the surface of the corrugated fin. The drain water adhering to the surface of the corrugated fin flows downward due to its own weight and is discharged from the heat exchanger.

However, in the above-mentioned heat exchanger, the drain water generated on the upper side of the corrugated fin flows downward, so that the drain water tends to stay on the lower side of the corrugated fin.

Further, in the above-mentioned heat exchanger, when drain water stays under the corrugated fin, the contact area of air with the corrugated fin may decrease, and the heat exchange efficiency may decrease.

An object of the present invention is to provide a heat exchanger capable of improving heat exchange efficiency by suppressing retention of drain water under the corrugated fin.

In order to achieve the above object, each heat exchanger of the present invention has a plurality of straight portions extending in the vertical direction and arranged at intervals in the horizontal direction, and one or a plurality of tubes through which the first fluid flows. And a plurality of corrugated fins extending in the vertical direction between the straight portions adjacent to each other in the one or a plurality of the tubes, and the first fluid flowing through the tube and the outside of the tube. A heat exchanger that exchanges heat with a second fluid flowing through the corrugated fin, wherein the corrugated fin is connected to a top surface connected to the outer surface of the straight line portion and one outer surface of the straight line portion adjacent to each other. It has an intermediate portion provided between the top portion and the top portion connected to the outer surface of the other straight portion, and the corrugated fin is provided with a heat transfer promoting piece by cutting up the intermediate portion. The heat transfer promoting piece located in a predetermined range below the corrugated fin is located outside the predetermined range in a range of 0 degrees or more and 90 degrees or less with respect to the intermediate portion. It is characterized in that it is larger than the angle formed by the heat transfer promoting piece and the heat transfer promoting piece.

According to the present invention, since the drainage property on the lower side of the corrugated fin where drain water tends to stay can be improved, the retention of drain water on the lower side of the corrugated fin can be suppressed and the heat exchange efficiency is improved. Can be made to.

It is a schematic block diagram of the heat pump cycle provided with the heat exchanger according to Embodiment 1 of this invention. It is a schematic block diagram of the heat exchanger which concerns on Embodiment 1 of this invention. It is an enlarged view of the main part of the heat exchanger which concerns on Embodiment 1 of this invention. It is an end view which shows the end face structure along the line I-I of FIG. It is an end view which shows the drainage mode in the corrugated fin of the heat exchanger which concerns on Embodiment 1 of this invention. FIG. 5A is an end view of the upper corrugated fin. FIG. 5B is an end view of the lower corrugated fin. It is an end view which shows the end face structure of the corrugated fin of the heat exchanger which concerns on Embodiment 2 of this invention. It is an end view which shows the drainage mode in the corrugated fin of the heat exchanger which concerns on Embodiment 2 of this invention. FIG. 7A is an end view of the upper corrugated fin. FIG. 7B is an end view of the lower corrugated fin. It is an end view which shows the end face structure of the corrugated fin of the heat exchanger which concerns on the modification of Embodiment 2 of this invention. It is an end view which shows the drainage mode in the corrugated fin of the heat exchanger which concerns on the modification of Embodiment 2 of this invention. FIG. 9A is an end view of the upper corrugated fin. FIG. 9B is an end view of the lower corrugated fin.

(Embodiment 1)
Hereinafter, the heat exchanger according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. However, the embodiments described below show some examples of the present invention and do not limit the contents of the present invention. Moreover, not all of the configurations and operations described in each embodiment limit the contents of the present invention. Moreover, not all of the configurations and operations described in each embodiment are essential as the configurations and operations of the present invention. The same components are designated by the same reference numerals, and duplicate description will be omitted.

[Outline configuration of heat pump cycle]
The schematic configuration of the heat pump cycle 1 provided with the heat exchanger according to the first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, the heat exchanger of the present invention is applied to, for example, an outdoor heat exchanger 10 connected to a heat pump cycle 1 provided in a vehicle air conditioner. The heat pump cycle 1 is configured by connecting the compressor 2, the indoor heat exchanger 3, the expansion valve 4, and the four-way valve 5 to each other by a refrigerant pipe 6 in addition to the outdoor heat exchanger 10. There is.

The heat pump cycle 1 performs a heating operation by circulating the refrigerant discharged from the compressor 2 in the order of the indoor heat exchanger 3, the expansion valve 4, and the outdoor heat exchanger 10. Further, the heat pump cycle 1 performs a cooling operation by circulating the refrigerant discharged from the compressor 2 in the order of the outdoor heat exchanger 10, the expansion valve 4, and the indoor heat exchanger 3. In the heat pump cycle 1, the heating operation and the cooling operation can be switched by switching the flow path of the refrigerant by the four-way valve 5.

[Construction of heat exchanger]
Next, the heat exchanger according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 5. In the following description, FIG. 1 will be referred to as appropriate.

As shown in FIG. 2, the outdoor heat exchangers 10 extend in the horizontal direction and are vertically spaced (vertically) between the pair of header tanks 20 and the pair of header tanks 20 which are vertically spaced from each other. It includes a plurality of tubes 30 extending in the direction) and arranged at intervals in the horizontal direction, and a plurality of corrugated fins 40 extending in the vertical direction between the tubes 30 adjacent to each other.

The header tank 20 is formed by closing both ends of a cylindrical member made of a metal such as aluminum in the axial direction with a lid member 21. The ends of the tubes 30 are connected to the outer peripheral portion of the header tank 20 at predetermined intervals in the axial direction of the header tank 20. Further, the inside of the header tank 20 is partitioned in the axial direction by a partition plate 22.

A refrigerant inflow port 23 for inflowing the refrigerant is provided on one end side of the upper header tank 20. A refrigerant outlet 24 for flowing out the refrigerant is provided on the other end side of the upper header tank 20.

The tube 30 is a member obtained by extruding a metal such as aluminum into a flat shape. The tube 30 has a straight portion 30a extending linearly, and both ends of the straight portion 30a are connected to the header tank 20.

As shown in FIG. 3, the corrugated fin 40 is a member formed by forming a metal plate such as aluminum so that the waveform is continuous in the vertical direction. The corrugated fin 40 has a top 41 connected to the outer surface of the tube 30, a top 41 connected to the outer surface of one of the adjacent tubes 30, and a top 41 connected to the outer surface of the other tube 30. It has an intermediate portion 42 provided between the two. The intermediate portion 42 is provided so as to be inclined with respect to the horizontal direction.

Further, as shown in FIGS. 2 and 3, the corrugated fins 40 are located outside the retention range (below the line segment m) and the lower corrugated fins 40b located in the retention range (below the line segment m) where the drain water tends to stay. It is composed of an upper corrugated fin 40a located above the line segment m). The line segment m indicates the boundary between the retention range and the outside of the retention range. The residence range is set according to environmental conditions such as temperature or humidity in which the heat exchanger is used. In the first embodiment, the height from the lower header tank 20 to the line segment m is, for example, 1/5 of the height of the heat exchanger.

In the corrugated fin 40, the vertical distance between the vertically adjacent intermediate portions 42 differs between the lower corrugated fin 40b and the upper corrugated fin 40a, and as shown in FIG. 4, the vertical distance between the lower corrugated fin 40b is different. T2 is larger than the vertical distance T1 in the upper corrugated fin 40a. Here, air flows in the direction indicated by the white arrow in the space formed by the intermediate portions 42 adjacent to each other on the upper and lower sides.

Further, as shown in FIGS. 3 and 4, the intermediate portion 42 of the corrugated fin 40 has a plurality of heat transfers for promoting heat transfer to the air that exchanges heat with the refrigerant by cutting up the member of the intermediate portion 42. The facilitator piece 43 is provided along the air flow direction. As shown in FIG. 4, the heat transfer promoting piece 43 extends from the connecting portion 43a connected to the intermediate portion 42 and the connecting portion 43a so that the tip thereof faces the upstream side in the air flow direction, and extends upward from the intermediate portion 42. The cut-up first cut-up piece 43b and the second cut-up piece 43c that extends from the connecting portion 43a so that the tip faces the downstream side in the air flow direction and is cut up downward from the intermediate portion 42. Have.

The surface formed by the connecting portion 43a, the first cut-up piece 43b, and the second cut-up piece 43c forms a flat surface. A slit 44 is formed in the intermediate portion 42 by cutting up the first cut-up piece 43b and the second cut-up piece 43c. The angle θ2 formed with respect to the intermediate portion 42 of the first cut-up piece 43b and the second cut-up piece 43c in the lower corrugated fin 40b is that of the first cut-up piece 43b and the second cut-up piece 43c in the upper corrugated fin 40a. It is larger than the angle θ1 formed with respect to the intermediate portion 42.
By inclining the angle θ2 at an angle larger than the angle θ1 in this way, the drainage property of the lower corrugated fin 40b where the drain water tends to stay is improved as compared with the drainage property of the upper corrugated fin 40a. As a result, the drain water in the lower corrugated fin 40b is removed from the outdoor heat exchanger 10 without staying.

However, the angle θ1 and the angle θ2 are angles in the range of 0 degrees or more and 90 degrees or less, and the drain water adhering to the surfaces of the connecting portion 43a, the first cut-up piece 43b, and the second cut-up piece 43c is due to its own weight. Any angle may be used as long as it flows downward from the slit 44.
When the angle θ2 exceeds 90 degrees, the inclination direction of the heat transfer promoting piece 43 in the lower corrugated fin 40b is reversed with respect to the inclination direction of the heat transfer promoting piece 43 in the upper corrugated fin 40a.
That is, in the upper corrugated fin 40a, the drain water flows downward from the downstream side in the air flow direction toward the upstream side in the flow direction, and in the lower corrugated fin 40b, the drain water flows from the upstream side in the air flow direction to the downstream side in the flow direction. It flows downward toward.
In such a case, the drain water flowing from the upper corrugated fin 40a to the lower corrugated fin 40b flows in the direction opposite to that of the upper corrugated fin 40a in the lower corrugated fin 40b, so that the drainage property is lowered.
Therefore, it is desirable that the angle θ2 is larger than the angle θ1 and is in the range of 0 degrees or more and 90 degrees or less.

The angles θ1 and θ2 in the first embodiment have a surface roughness (Ra) of the corrugated fin 40 in the range of 0.87 μm or more and 1.11 μm or less, and condensed water adhering to the surface of the heat transfer promoting piece 43 due to dew condensation. When (drain water) is 4 × 10 ^-3 μm ³ , the range of 42 degrees or more and 90 degrees or less is preferable.
Under the above conditions, the drain water adhering to the surface of the heat transfer promoting piece 43 tends to flow downward from the slit 44 due to its own weight. Therefore, the retention of drain water is suppressed in the lower corrugated fin 40b.

Further, as shown in FIG. 4, the vertical width of the space formed between the corrugated fins 40 in the vertical direction, that is, the intermediate portion 42 having the heat transfer promoting pieces 43 adjacent to each other in the vertical direction is downward. The corrugated fin 40b and the upper corrugated fin 40a are different. The vertical width t2 of the lower corrugated fin 40b is equal to or greater than the vertical width t1 of the upper corrugated fin 40a.

[Explanation of heat exchanger drainage]
Next, the drainage of the heat exchanger according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 5. In the following description, FIG. 1 will be referred to as appropriate.

In the outdoor heat exchanger 10, as shown in FIG. 2, the refrigerant that has flowed into the upper header tank 20 from the refrigerant inflow port 23 flows out of the refrigerant outflow port 24 after flowing through the header tank 20 and the tube 30. Since the inside of the header tank 20 is axially partitioned by the partition plate 22, the refrigerant flowing through the header tank 20 and the tube 30 meanders from one side to the other in the width direction as shown by an arrow.

If the heating operation is performed in an environment where the outside of the vehicle compartment A is low in temperature, dew condensation or frost formation may occur on the outdoor heat exchanger 10. When dew condensation occurs on the outdoor heat exchanger 10, condensed water (drain water) due to the dew condensation adheres to the outer surface of the tube 30 and the surface of the corrugated fin 40. Further, when the defrosting operation is executed to remove the frost adhering to the outdoor heat exchanger 10, the molten water (drain water) generated by melting the frost with the high temperature refrigerant is the outer surface of the tube 30. , And, it becomes a state of being attached to the surface of the corrugated fin 40.

The drain water adhering to the outer surface of the tube 30 and the surface of the corrugated fin 40 flows downward along the tube 30 and the corrugated fin 40 by its own weight and is excluded from the outdoor heat exchanger 10.

As shown in FIGS. 5 (a) and 5 (b), the drain water adhering to the surface of the heat transfer promoting piece 43 is formed by the connecting portion 43a, the first cut-up piece 43b, and the second cut-up piece 43c. It flows downward from the slit 44 along the plane.

At this time, the angle θ2 formed by the first cut-up piece 43b and the second cut-up piece 43c in the lower corrugated fin 40b with respect to the intermediate portion 42 is in the upper corrugated fin 40a as shown in FIG. 5 (b). It is larger than the angle θ1 formed with respect to the intermediate portion 42 of the first cut-up piece 43b and the second cut-up piece 43c. As a result, the gravity component greatly acts on the drain water 50 adhering to the surface of the heat transfer promoting piece 43 located on the lower corrugated fin 40b.

Therefore, the drain water 50 adhering to the heat transfer promoting piece 43 located on the lower corrugated fin 40b, together with the drain water 50 falling from the upper corrugated fin 40a, is connected to the connecting portion 43a, the first cut-up piece 43b, and the second. It flows downward from the slit 44 along the plane formed by the cut-up piece 43c.

In other words, since the lower corrugated fin 40b has a higher drainage property than the upper corrugated fin 40a, the drain water 50 is eliminated from the lower corrugated fin 40b without staying.

Further, as shown in FIGS. 5A and 5B, the vertical spacing T2 of the vertically adjacent intermediate portions 42 in the lower corrugated fin 40b is the vertically adjacent intermediate portions in the upper corrugated fin 40a. It is larger than the vertical interval T1 of 42. Further, the vertical width t2 of the space formed between the intermediate portions 42 having the heat transfer promoting pieces 43 adjacent to each other in the vertical direction is equal to or larger than the vertical width t1 of the upper corrugated fin 40a.

As a result, in the lower corrugated fin 40b, even if the first cut-up piece 43b and the second cut-up piece 43c are cut up at an angle θ2 larger than the angle θ1, an intermediate having heat transfer promoting pieces 43 adjacent to each other on the upper and lower sides. The vertical width of the space formed between the portions 42 is secured.

Therefore, in the lower corrugated fin 40b, the drainage property is improved and the retention of the drain water 50 is suppressed. Further, since the air flow in the gap between the lower corrugated fins 40b is not obstructed, it is possible to prevent the lower corrugated fins 40b from increasing the flow resistance as compared with the upper corrugated fins 40a.

[Effect of Embodiment 1]
As described above, the heat exchangers of the first embodiment each extend in the vertical direction and are arranged at intervals in the horizontal direction, have straight portions 30a formed in a flat shape, and allow the refrigerant to flow inside. A plurality of tubes 30 and a plurality of corrugated fins 40 extending in the vertical direction between the tubes 30 adjacent to each other are provided. Further, the heat exchanger of the first embodiment exchanges heat between the refrigerant as the first fluid flowing in the tube 30 and the air as the second fluid flowing outside the tube 30. Then, the heat transfer promoting piece 43 provided by cutting up the intermediate portion 42 of the corrugated fin 40 is equal to the angle θ1 of the upper corrugated fin 40a within the range of 0 degree or more and 90 degrees or less in the lower corrugated fin 40b. It is tilted at a large angle θ2.

Therefore, in the first embodiment, the drainage property on the lower side of the corrugated fin 40 where the drain water 50 tends to stay can be improved, so that the retention of the drain water 50 on the lower side of the corrugated fin 40 can be suppressed. It is possible to improve the heat exchange efficiency.

Further, in the first embodiment, the vertical distance T2 of the vertically adjacent intermediate portions 42 in the lower corrugated fin 40b is larger than the vertical distance T1 of the upper corrugated fin 40a.

Therefore, in the first embodiment, the retention of the drain water 50 between the vertically adjacent intermediate portions 42 in the lower corrugated fin 40b is further suppressed, so that the drainage property is improved.

Further, in the first embodiment, the vertical width t2 of the space formed between the intermediate portions 42 having the heat transfer promoting pieces 43 adjacent to each other in the lower corrugated fin 40b is the vertical direction of the upper corrugated fin 40a. Width t1 or more.

Therefore, in the first embodiment, even if the heat transfer promoting piece 43 located at the lower corrugated fin 40b is cut up from the intermediate portion 42 at an angle θ2 larger than the angle θ1, the air in the gap of the lower corrugated fin 40b Distribution will not be hindered. As a result, it is possible to prevent the lower corrugated fin 40b from increasing the flow resistance as compared with the upper corrugated fin 40a.

Further, in the first embodiment, the surface formed by the connecting portion 43a, the first cut-up piece 43b, and the second cut-up piece 43c forms a flat surface.

Therefore, in the first embodiment, the drain water 50 adhering to the surface of the heat transfer promoting piece 43 located on the lower corrugated fin 40b can be reliably removed from the slit 44 downward.

(Embodiment 2)
Subsequently, the heat exchanger according to the second embodiment of the present invention will be described with reference to FIGS. 6 and 7. In the following description, FIGS. 4 and 5 will be referred to as appropriate.

As shown in FIGS. 6 and 7, the corrugated fin 40 in the second embodiment is composed of a lower corrugated fin 40b and an upper corrugated fin 40a as in FIGS. 4 and 5, and is composed of a lower corrugated fin 40a. The angle θ2 at the corrugated fin 40b is larger than the angle θ1 at the upper corrugated fin 40a.

The angle θ1 and the angle θ2 in the second embodiment are angles in the range of 0 degree or more and 90 degrees or less, similarly to the angle θ1 and the angle θ2 of the first embodiment, and the connecting portions 431a and 432a and the first cut-up piece 431b. The angle may be such that the drain water 50 adhering to the surfaces of the second cut-up pieces 431c and 432c flows downward from the slit 44 due to its own weight.

Similar to FIGS. 4 and 5, the corrugated fin 40 in the second embodiment is formed so that the vertical width t2 of the lower corrugated fin 40b is equal to or more than the vertical width t1 of the upper corrugated fin 40a. .. Similar to the first embodiment, these have high drainage in the retention range (below the line segment m). Further, as in FIGS. 4 and 5, air flows in the direction indicated by the white arrow in the space formed by the vertically adjacent intermediate portions 42.

However, as shown in FIGS. 6 and 7, the corrugated fin 40 in the second embodiment has a conversion portion 45 substantially at the center of the intermediate portion 42 in the air flow direction, unlike the corrugated fin 40 in the first embodiment. are doing. Further, unlike the heat transfer promoting piece 43 of the first embodiment, the heat transfer promoting piece in the second embodiment has its inclination direction reversed with the conversion portion 45 as a boundary. Hereinafter, the differences from the first embodiment will be mainly described.

As shown in FIG. 6, the intermediate portion 42 of the corrugated fin 40 in the second embodiment has a heat transfer promoting piece 431 located upstream of the conversion portion 45 in the air flow direction with the conversion portion 45 as a predetermined position. , A plurality of heat transfer promoting pieces 432 located on the downstream side in the air flow direction with respect to the conversion portion 45 are provided along the air flow direction.

The heat transfer promoting piece 431 located on the upstream side in the air flow direction with respect to the conversion portion 45 has a connecting portion 431a, a first cut-up piece 431b, and a second cut-up piece 431c. The connecting portion 431a is connected to the intermediate portion 42. The first cut-up piece 431b extends from the connecting portion 431a so that the tip thereof faces the downstream side in the air flow direction, and is cut upward from the intermediate portion 42. The second cut-up piece 431c extends from the connecting portion 431a so that the tip thereof faces the upstream side in the air flow direction, and is cut up downward from the intermediate portion 42. The second cut-up piece 431c is arranged on the upstream side in the air flow direction with respect to the first cut-up piece 431b.

The heat transfer promoting piece 432 located on the downstream side in the air flow direction with respect to the conversion portion 45 has a connecting portion 432a, a first cut-up piece 432b, and a second cut-up piece 432c. The connecting portion 432a is connected to the intermediate portion 42. The first cut-up piece 432b extends from the connecting portion 432a so that the tip thereof faces the upstream side in the air flow direction, and is cut upward from the intermediate portion 42. The second cut-up piece 432c extends from the connecting portion 431a so that the tip thereof faces the downstream side in the air flow direction, and is cut up downward from the intermediate portion 42. The second cut-up piece 432c is arranged on the downstream side in the air flow direction with respect to the first cut-up piece 432b.

As a result, the heat transfer promoting piece 431 located upstream of the conversion portion 45 in the air flow direction connects the drain water 50 adhering to the surface as shown in FIGS. 7 (a) and 7 (b). A plane formed by the portion 431a, the first cut-up piece 431b, and the second cut-up piece 431c is transmitted, and the air flows downward from the downstream side in the flow direction to the upstream side in the flow direction. Then, the drain water 50 is guided to the end of the intermediate portion 42 on the upstream side in the air flow direction at the lower corrugated fin 40b, and is excluded from the heat exchanger.

Further, the heat transfer promoting piece 432 located on the downstream side in the air flow direction from the conversion portion 45 allows the drain water 50 adhering to the surface to be collected by the connecting portion 432a, the first cut-up piece 432b, and the second cut-up piece 432c. The air flows downward from the upstream side in the flow direction to the downstream side in the flow direction along the formed plane. Then, the drain water 50 is guided to the end of the intermediate portion 42 on the downstream side in the air flow direction at the lower corrugated fin 40b, and is excluded from the heat exchanger.

When the angle θ2 exceeds 90 degrees, the inclination direction of the heat transfer promoting piece 43 in the lower corrugated fin 40b is reversed with respect to the inclination direction of the heat transfer promoting piece 43 in the upper corrugated fin 40a.
That is, on the upstream side of the upper corrugated fin 40a in the air flow direction, the drain water 50 flows downward from the downstream side of the air flow direction toward the upstream side of the flow direction, and on the upstream side of the lower corrugated fin 40b in the air flow direction. The drain water 50 flows downward from the upstream side in the air distribution direction toward the downstream side in the distribution direction.
Further, on the downstream side of the upper corrugated fin 40a in the air flow direction, the drain water 50 flows downward from the upstream side of the air flow direction toward the downstream side of the flow direction, and on the downstream side of the lower corrugated fin 40b in the air flow direction. The drain water 50 flows downward from the downstream side in the air flow direction toward the upstream side in the flow direction.
In such a case, in the upper corrugated fin 40a, the drain water 50 flows toward the outside of the intermediate portion 42 with the conversion portion 45 as the boundary, whereas in the lower corrugated fin 40b, the drain water flows with the conversion portion 45 as the boundary. Since 50 flows toward the inside of the intermediate portion 42, the drainage property is lowered.
Therefore, it is desirable that the angle θ2 is larger than the angle θ1 and is in the range of 0 degrees or more and 90 degrees or less.

[Effect of Embodiment 2]
As described above, according to the second embodiment, in the case of the upstream side in the air flow direction from the conversion portion 45, the drain water 50 is the air in the intermediate portion 42 in the lower corrugated fin 40b by the heat transfer promoting piece 431. It is guided to the end on the upstream side in the distribution direction and removed from the heat exchanger. Further, according to the second embodiment, when the drain water 50 is downstream of the conversion portion 45 in the air flow direction, the drain water 50 is in the air flow direction of the intermediate portion 42 in the lower corrugated fin 40b by the heat transfer promoting piece 432. It is guided to the downstream end and removed from the heat exchanger. Therefore, according to the second embodiment, the drainage property is further improved by reversing the inclination direction of the heat transfer promoting piece with the conversion portion 45 as a boundary.

(Modification example)
Subsequently, the heat exchanger according to the modified example of the second embodiment will be described with reference to FIGS. 8 and 9. In the following description, FIGS. 6 and 7 will be referred to as appropriate.

In this modification, as shown in FIG. 8, the conversion portion 45 may be provided on the upstream side in the distribution direction of the intermediate portion 42 in the air flow direction. In this case, the heat transfer promoting piece 431 in the upper corrugated fin 40a is inclined at an angle θ3 larger than the angle θ1. Further, the heat transfer promoting piece 431 in the lower corrugated fin 40b is inclined at an angle θ4 larger than the angle θ2.

However, the angle θ3 and the angle θ4 are angles in the range of 0 degree or more and 90 degrees or less like the angle θ1 and the angle θ2. Further, the angles θ3 and θ4 are angles such that the drain water 50 adhering to the surfaces of the connecting portion 431a, the first cut-up piece 431b and the second cut-up piece 431c flows downward from the slit 44 due to its own weight. good.

When the angle θ2 and the angle θ4 in this modification exceed 90 degrees, the inclination direction of the heat transfer promoting piece 43 in the lower corrugated fin 40b is the same as in the case where the angle θ2 in the second embodiment exceeds 90 degrees. It is inverted with respect to the inclination direction of the heat transfer promoting piece 43 in the upper corrugated fin 40a.
That is, on the upstream side of the upper corrugated fin 40a in the air flow direction, the drain water 50 flows downward from the downstream side of the air flow direction toward the upstream side of the flow direction, and on the upstream side of the lower corrugated fin 40b in the air flow direction. The drain water 50 flows downward from the upstream side in the air distribution direction toward the downstream side in the distribution direction.
Further, on the downstream side of the upper corrugated fin 40a in the air flow direction, the drain water 50 flows downward from the upstream side of the air flow direction toward the downstream side of the flow direction, and on the downstream side of the lower corrugated fin 40b in the air flow direction. The drain water 50 flows downward from the downstream side in the air flow direction toward the upstream side in the flow direction.
In such a case, in the upper corrugated fin 40a, the drain water 50 flows toward the outside of the intermediate portion 42 with the conversion portion 45 as the boundary, whereas in the lower corrugated fin 40b, the drain water flows with the conversion portion 45 as the boundary. Since 50 flows toward the inside of the intermediate portion 42, the drainage property is lowered.
Therefore, it is desirable that the angle θ2 and the angle θ4 in the present modification are larger than the angle θ1 and the angle θ3 and are in the range of 0 degrees or more and 90 degrees or less, similarly to the angle θ2 in the second embodiment.

Further, the angle θ3 and the angle θ4 in this modified example have a surface roughness (Ra) of the corrugated fin 40 in the range of 0.87 μm or more and 1.11 μm or less, similarly to the angle θ1 and the angle θ2, and the heat transfer promoting piece due to dew condensation. When the condensed water (drain water 50) adhering to the surface of 431 and 432 is 4 × 10 ^-3 μm ³ , the range of 42 degrees or more and 90 degrees or less is preferable.
Under the above conditions, the drain water adhering to the surface of the heat transfer promoting piece 43 tends to flow downward from the slit 44 due to its own weight. Therefore, the retention of drain water is suppressed in the lower corrugated fin 40b.

As shown in FIGS. 9 (a) and 9 (b), the heat transfer promoting piece 431 in this modified example is obtained by cutting the drain water 50 adhering to the surface into the connecting portion 431a, the first cut-up piece 431b, and the second cut. The air flows downward from the downstream side in the flow direction to the upstream side in the flow direction along the plane formed by the raising piece 431c. Then, the drain water 50 is guided to the end of the intermediate portion 42 on the upstream side in the air flow direction at the lower corrugated fin 40b, and is excluded from the heat exchanger.

As described above, according to this modification, the conversion portion 45 is provided on the upstream side in the air flow direction from the substantially center of the intermediate portion 42, and the heat transfer promoting piece 431 located on the upstream side in the air flow direction is inclined. It is larger than the heat transfer promoting piece 432 located on the downstream side in the distribution direction. Therefore, on the upstream side of the conversion portion 45 in the air flow direction, the drain water 50 adhering to the surface of the heat transfer promoting piece 431 flows downward without being hindered by the air flow.

[Other]
In each of the above-described embodiments, the heat exchanger of the present invention is applied to the outdoor heat exchanger 10 of the air conditioner for vehicles, but the heat exchanger is not limited to the one that exchanges heat between the refrigerant and the air, and is not limited to the one that exchanges heat with the fluid. The heat exchanger of the present invention can be applied as long as it is a heat exchanger that needs to remove drain water while exchanging heat with a fluid.

Further, in each of the above-described embodiments, a plurality of tubes 30 extending in the vertical direction and arranged at intervals in the horizontal direction are shown between the header tanks 20 arranged in the vertical direction, but the present invention is not limited to this. It shall be. The tube 30 may be, for example, a single meandering tube composed of a plurality of straight portions and a top portion connecting adjacent straight portions. In this case, the corrugated fins 40 are provided so as to extend in the vertical direction between adjacent straight portions of the tubes.

Further, in each of the above-described embodiments, the process of draining the molten water generated by the defrosting operation from the outdoor heat exchanger 10 has been described, but the heat exchanger of the present invention drains the condensed water generated by the cooling operation. It is also effective for. In this case, the heat exchanger of the present invention is applied to the indoor heat exchanger 3.

Further, in each of the above-described embodiments, the drainage property of the corrugated fin 40 is improved by making the angle θ2 larger than the angle θ1, but the corrugated fin 40 is made by smoothing the surface roughness of the corrugated fin 40. The drainage property can be further improved. In this case, the surface roughness (Ra) of the corrugated fin 40 is preferably in the range of 0.27 μm or more and 0.33 μm or less.

1 Heat pump cycle 2 Compressor 3 Indoor heat exchanger 4 Expansion valve 5 Four-way valve 6 Refrigerant pipe 10 Outdoor heat exchanger (heat exchanger)
20 Header tank 21 Lid member 22 Partition plate 23 Refrigerant inflow port 24 Refrigerant outflow port 30 Tube 30a Straight part 40 Corrugated fin 40a Upper corrugated fin 40b Lower corrugated fin 41 Top 42 Intermediate part 43 Heat transfer promoting piece 431 Heat transfer promoting piece 431a Connecting part 431b 1st cut-up piece 431c 2nd cut-up piece 432 Heat transfer promoting piece 432a Connecting part 432b 1st cut-up piece 432c 2nd cut-up piece 43a Connecting part 43b 1st cut-up piece 43c 2nd cut-up piece 44 Slit 45 Conversion part 50 Drain water

Claims (6)

One or more tubes for passing the first fluid and the straight portions adjacent to each other in the one or more tubes, each having a plurality of straight portions extending in the vertical direction and arranged at intervals in the horizontal direction. A heat exchanger comprising a plurality of corrugated fins extending in the vertical direction between the tubes and exchanging heat between the first fluid flowing in the tube and the second fluid flowing outside the tube. There,
The corrugated fin is between a top connected to the outer surface of the straight portion and a top connected to one outer surface of the straight portions adjacent to each other and a top connected to the outer surface of the other straight portion. Has an intermediate part provided in
The corrugated fin is provided with a heat transfer promoting piece by cutting up the intermediate portion.
The heat transfer promoting piece located in a predetermined range below the corrugated fin has the intermediate portion located outside the predetermined range and the intermediate portion located outside the predetermined range in an angle formed with respect to the intermediate portion of 0 degrees or more and 90 degrees or less. Larger than the angle formed by the heat transfer promoter pieces,
A heat exchanger characterized by that. According to claim 1, the distance between the plurality of corrugated fins in the vertical direction of the intermediate portions vertically adjacent to each other in the predetermined range is larger than the vertical distance between the intermediate portions vertically adjacent to each other in the predetermined range. The heat exchanger described. The space formed between the intermediate portions having the heat transfer promoting pieces adjacent to each other vertically between the straight portions adjacent to each other has the width in the vertical direction in the predetermined range but the second width outside the predetermined range. The heat exchanger according to claim 2, which is equal to or larger than the vertical width of the fluid flow path. The heat transfer promoting piece is formed from a connecting portion connected to the intermediate portion, a first cut-up piece extending from the connecting portion and cut up in one direction in the vertical direction with respect to the intermediate portion, and the connecting portion. It has a second cut-up piece that extends and is cut up on the other side in the vertical direction with respect to the intermediate part, and is formed by the connecting portion, the first cut-up piece, and the second cut-up piece. The heat exchanger according to any one of claims 1 to 3, wherein the surface forms a flat surface. A plurality of the heat transfer promoting pieces are provided in the intermediate portion along the flow direction of the second fluid.
The first cut-up piece is cut up upward with respect to the intermediate portion.
The second cut-up piece is cut up downward with respect to the intermediate portion.
In the heat transfer promoting piece located on the upstream side in the flow direction of the second fluid from the predetermined position in the intermediate portion, the first cut-up piece flows the second fluid to the second cut-up piece. Located on the downstream side of the direction,
In the heat transfer promoting piece located downstream of the predetermined position in the intermediate portion in the flow direction of the second fluid, the first cut-up piece is the second fluid with respect to the second cut-up piece. The heat exchanger according to claim 4, which is arranged on the upstream side in the distribution direction. The heat transfer promoting piece located upstream of the predetermined position in the intermediate portion in the flow direction of the second fluid has an angle formed with respect to the intermediate portion in the flow direction of the second fluid than the predetermined position. The heat exchanger according to claim 5, wherein the heat transfer promoting piece located on the downstream side is larger than the angle formed with respect to the intermediate portion.

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