JP7006376B2 - Heat exchanger - Google Patents

Description

The present invention relates to a heat exchanger that exchanges heat between a refrigerant flowing in a heat transfer tube and a fluid such as air.

A parallel flow type heat exchanger composed of a plurality of flat heat transfer tubes (flat tubes) and a plurality of heat transfer fins is known. Heat transfer fins used in this parallel flow heat exchanger include corrugated fins and plate-shaped fins. The corrugated fins form a band-shaped metal plate in a wavy shape and are inserted between each of a plurality of heat transfer tubes arranged one above the other. The plate-shaped fin is a strip-shaped metal plate, and a plurality of plate-shaped fins are laminated at predetermined intervals, and a heat transfer tube is inserted from one side in the width direction. These heat transfer fins are joined to the heat transfer tube by brazing.

In such a parallel flow type heat exchanger, heat is exchanged between the fluid (for example, air) flowing between the plurality of heat transfer fins and the refrigerant flowing inside the heat transfer tube. At this time, the heat transfer fins function to promote heat transfer between the fluid and the refrigerant. In order to improve the heat transfer performance of the heat transfer fin, it is known that the surface of the heat transfer fin is cut up to form a louver. The heat transfer performance of the heat transfer fins can be improved by the front edge effect of the louver and the generation of turbulence, thereby improving the heat exchange performance of the heat exchanger.

For example, Patent Document 1 discloses a fin for a heat exchanger having a plurality of louvers arranged along the flow direction of a fluid. The plurality of louvers are formed in opposite directions with the turning portion formed parallel to the flow direction of the fluid as a boundary, and the first louver and the second louver having a smaller cutting angle than the first louver. It has at least two types of louvers, and a second louver is arranged next to the turning portion. As a result, the flow of the fluid from the second louver on the windward side of the turning portion is reversed by the turning portion, and the fluid easily flows between the first louvers by the second louver on the leeward side from the turning portion. By making the distances between adjacent louvers equal, the fluid flows evenly between the louvers, which improves the heat transfer performance of the heat transfer fins.

Japanese Unexamined Patent Publication No. 2013-195024

However, since the fin structure described in Patent Document 1 is premised on application to a heat exchanger for in-vehicle use, a fin structure having the same distance between louvers and different louver heights as described in Patent Document 1 is used. When applied to a heat exchanger for refrigeration and air conditioning, there is a problem that it is difficult to obtain the desired heat exchange performance.

That is, in heat exchangers for refrigeration and air conditioning, the inflow rate of fluid is slower than that for heat exchangers for in-vehicle use. Therefore, when louvers with different heights are mixed, the flow of fluid parallel to the fin surface is high. It is hindered by a large (large cutting angle) louver, and a sufficient amount of fluid cannot flow between the small height (small cutting angle) louvers. As a result, the heat transfer performance varies between the windward side and the leeward side of the heat transfer fin, and it is not possible to improve the heat exchange performance as expected.

In view of the above circumstances, an object of the present invention is to provide a heat exchanger capable of improving heat exchange performance even when the flow velocity is relatively slow.

In order to achieve the above object, the heat exchanger according to one embodiment of the present invention includes a plurality of heat transfer tubes and a plurality of heat transfer fins.
The plurality of heat transfer tubes have a flow path through which the refrigerant flows along the first axial direction, and are arranged in the second axial direction orthogonal to the first axial direction.
The plurality of heat transfer fins are arranged in the first axial direction and are joined to the plurality of heat transfer tubes.
The plurality of heat transfer fins have a heat transfer portion located between the plurality of heat transfer tubes and forming a ventilation path through which a fluid passes, and the heat transfer portion provided in the first axial direction and the second. Each has a louver portion including a plurality of louvers arranged in a third axial direction orthogonal to the axial direction.
The plurality of louvers have a certain height with respect to the heat transfer portion.
The cutting angle of the plurality of louvers with respect to the heat transfer portion gradually decreases from one end side to the other end side in the third axial direction.

The arrangement pitch of the plurality of louvers may gradually increase from the one end side toward the other end side.

The plurality of heat transfer fins are composed of plate-shaped fins provided in the heat transfer portion and having a plurality of tabs for adjusting the arrangement interval of the plurality of heat transfer fins, and a part of the plurality of tabs is the louver. It may be provided on the other end side in the third axial direction with respect to the portion.

As described above, according to the present invention, it is possible to improve the heat exchange performance of the heat exchanger even when the flow velocity is relatively slow.

It is a front view of the heat exchanger which concerns on one Embodiment of this invention. FIG. 1 is a partial cross-sectional view taken along the line AA in FIG. FIG. 2 is a cross-sectional view taken along the line BB in FIG. It is a perspective view which shows the form of the louver part in the said heat exchanger.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of the heat exchanger 100 according to an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view taken along the line AA in FIG.
In each figure, the X-axis (first axis), the Y-axis (second axis), and the Z-axis (third axis) show three axis directions orthogonal to each other, and the X-axis direction is the left-right direction. (Width direction) and Y-axis direction correspond to the vertical direction (height direction).

[Basic configuration]
The heat exchanger of the present embodiment is a heat exchanger (condenser or evaporator) for refrigeration and air conditioning and for hot water supply / hot water heating. Hereinafter, the basic configuration of the heat exchanger 100 will be described.

The heat exchanger 100 includes a first header 11, a second header 12, a plurality of heat transfer tubes 20, and a plurality of heat transfer fins 30.
The first header 11, the second header 12, the heat transfer tube 20, and the heat transfer fin 30 are all members made of an aluminum alloy, and their respective joining is performed by brazing.

Both the first header 11 and the second header 12 are formed in an elongated cylindrical shape, for example, in which both ends in the longitudinal direction (Y-axis direction) are closed. The first header 11 is arranged on one end side in the width direction of the heat exchanger 100, and the second header 12 is arranged on the other end side.

The plurality of heat transfer tubes 20 extend linearly in the left-right direction and are arranged at intervals in the vertical direction. In the present embodiment, each heat transfer tube 20 is composed of a flat tube having a main surface parallel to the flow direction (Z-axis direction) of the fluid (air) as shown in FIG. Each heat transfer tube 20 has a plurality of flow paths 21 through which the refrigerant flows. The flow paths 21 are formed independently of each other and are formed at intervals in the fluid flow direction (Z-axis direction). One end of each heat transfer tube 20 is inserted into the first header 11, the other end of each heat transfer tube 20 is inserted into the second header 12, and the first header 11 and the second header 12 communicate with each other via the flow path 21. ..

The plurality of heat transfer fins 30 are arranged in the left-right direction (X-axis direction) and are thermally connected to the plurality of heat transfer tubes 20. In the present embodiment, each heat transfer fin 30 is a plate-shaped fin extending linearly in the vertical direction, and is formed into a shape as shown in FIG. 2 by press working or the like. As shown by the arrow W in FIG. 2, air as a fluid flows in the Z-axis direction. Hereinafter, in FIG. 2, the left side is also referred to as a leeward side, and the right side is also referred to as a leeward side.

Each heat transfer fin 30 is formed in a vertically long plate shape, and as shown in FIG. 2, a horizontally long notch 31 extending from the leeward end portion 302 in the lateral direction toward the leeward end portion 301 is provided. , A large number of heat transfer fins 30 are formed at a first interval in the longitudinal direction (Y-axis direction). By inserting the heat transfer tube 20 into these notches 31, the heat transfer tube 20 is arranged with a first interval d1 in the vertical direction as shown in FIG.

Further, as shown in FIG. 1, each heat transfer fin 30 has an interval determined in the left-right direction (X-axis direction) of the heat exchanger 100 in consideration of the heat exchange capacity of the heat exchanger 100, ventilation resistance, and the like. They are arranged at a second interval d2. Then, a plurality of ventilation passages 40 surrounded by heat transfer tubes 20 adjacent to each other vertically and heat transfer fins 30 adjacent to the left and right are formed side by side in each of the vertical direction and the horizontal direction.

The plurality of heat transfer tubes 20 and the plurality of heat transfer fins 30 are orthogonal to each other, and as shown in FIG. 2, the heat transfer tubes 20 are in contact with one of the plurality of ventilation passages 40 among the heat transfer fins 30, and the heat transfer tubes are vertically adjacent to each other. The region located between 20 is the heat transfer unit 32 that exchanges heat with the air flowing in the direction indicated by the arrow W. Further, a region which is a part of the heat transfer fin 30 and is located on the windward end portion 301 side of the heat transfer fin 30 from the notch portion 31 is continuously formed from the upper end to the lower end of the heat transfer fin 30. It is a flowing water section (communication section) 33. When the heat exchanger 100 is configured as an evaporator, the water flow unit 33 forms a flow path through which the condensed water flows vertically downward.

Each heat transfer portion 32 of the heat transfer fin 30 is a flat surface parallel to the YZ plane, and each heat transfer portion 32 has a plurality of louvers arranged along the air flow direction (Z-axis direction). A louver portion 50 including the louver portion 50 is provided. The louver portion 50 promotes heat transfer of the heat transfer fin 30 by the leading edge effect. Further, the louver portion 50 guides air from one ventilation passage 40 adjacent to the heat transfer portion 32 to the other ventilation passage 40, and a part of the heat transfer portion 32 is cut up and transferred in the X-axis direction. It is formed so as to be inclined diagonally with respect to the heat portion.

The heat transfer fins 30 further have a plurality of tabs for adjusting the arrangement spacing of the adjacent heat transfer fins 30. The plurality of tabs have a first tab 61 provided in the water flow unit 33 and a second tab 62 provided in the heat transfer unit 32, and these have vertical portions of the water flow unit 33 and the heat transfer unit 32. It is formed by cutting up in the direction (X-axis direction in FIG. 2). A plurality of first tabs 61 and second tabs 62 are provided at appropriate positions along the longitudinal direction of the heat transfer fins 30. In particular, the second tab 62 is provided on the leeward end 302 side of the heat transfer fin 30 with respect to the louver portion 50. The forming position of the first tab 61 is not particularly limited, and in the present embodiment, the first tab 61 is provided at a position facing the second tab 62 in the Z-axis direction with the louver portion 50 interposed therebetween.

[Louver part]
Hereinafter, the details of the louver portion 50 will be described.
FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2, and FIG. 4 is a perspective view showing the form of the louver portion 50.

The louver portion 50 includes a plurality of slit-shaped openings 50w that diagonally penetrate the heat transfer portion 32. In the present embodiment, the louver portion 50 includes six louvers of a first louver 51, a second louver 52, a third louver 53, a fourth louver 54, a fifth louver 55, and a sixth louver 56, and these are in that order. The heat transfer fins 30 are arranged from the windward end 301 (first end) to the leeward end 302 (second end). Of course, the number of louvers is not limited to this, and can be arbitrarily set according to the size of the heat transfer unit 32 and the like.

The first louver 51 to the sixth louver 56 have a substantially rectangular shape whose width direction is parallel to the longitudinal direction (Y-axis direction) of the heat transfer fin 30, and the heat transfer portion 32 has a heat transfer portion 32 as shown in FIG. It is formed by cutting up on one main surface 32a or the other main surface 32b side around an axis parallel to the Y-axis direction. In the illustrated example, the first louver 51 is on the other main surface 32b side, and for the second louvers 52 to the fifth louver 55, the windward side is on one main surface 32a side, the leeward side is on the other main surface 32b side, and , The sixth louver 56 is cut up on one main surface 32a side, respectively.

The first louver 51 to the sixth louver 56 are formed to have the same width (Lw) as shown in FIG. 2, and have a constant height (H) with respect to the heat transfer portion 31 as shown in FIG. It is cut up by. The constant height means that the cut-up heights of the louvers 51 to 56 with respect to the heat transfer portion 32 are substantially the same height, and the height is not limited to the case where they are completely the same. Variations may be included.

Further, as shown in FIG. 3, the cutting angles of the first louver 51 to the sixth louver 56 with respect to the heat transfer portion 32 are in that order (from the windward end portion 301 side to the leeward side end portion 302 side). The length of the first louver 51 to the sixth louver 56 (the size in the direction orthogonal to the width direction) is gradually increased. The cutting angle of each louver 51 to 56 is not particularly limited, and is appropriately set according to the required heat transfer performance, and can be arbitrarily set, for example, in the range of more than 0 ° and 90 ° or less.

Further, in the present embodiment, the first louver 51 to the sixth louver 56 are arranged in close proximity to each other. As a result, the arrangement pitches P1 to P6 of the first louver 51 to the sixth louver 56 are set to gradually increase in that order (from the windward end 301 side to the leeward end 302 side). ..

[Action of heat exchanger]
In the heat exchanger 100 of the present embodiment configured as described above, air is flowed from the windward end portion 301 of the heat transfer fin 30 toward the leeward side end portion 302 by a blower fan (not shown). The air flowed by the blower fan passes through the plurality of ventilation passages 40 partitioned by the plurality of heat transfer tubes 20 and the heat transfer fins 30, and flows through the flow path 21 through the heat transfer portion 32 of each heat transfer fin 30. Heat exchange with the refrigerant. As a result, when the heat exchanger 100 is a condenser, the refrigerant flowing through the flow path 21 of the heat transfer tube 20 is condensed, and when the heat exchanger 100 is an evaporator, the refrigerant flowing through the flow path 21 of the heat transfer tube 20 is evaporated. ..

The flow velocity of the air sent from the blower fan of the air conditioner is relatively slower than that of, for example, a heat exchanger (for example, a radiator) for a vehicle, and the heat transfer fin 30 is sent from the wind upper end 301 to the ventilation passage 40. The invading air flows parallel to the surface of the heat transfer portion 32 toward the leeward end portion 302. A part of the air in the ventilation passage 40 flows between the first louver 51 and the sixth louver 56 as shown by an arrow in FIG. 3, and is separated from the ventilation passage 40 partitioned by one main surface 32a of the heat transfer portion 32. By being guided to the ventilation passage 40 partitioned by the other main surface 32b, heat transfer is performed between one main surface 32a of the heat transfer unit 32 and the other main surface 32b and the air.

According to the present embodiment, since the first louver 51 to the sixth louver 56 constituting the louver portion 50 are formed at a constant height with respect to the heat transfer portion 32, the cut-up heights of the louvers are different from the conventional ones. Compared to the fin structure of, air can flow evenly between each louver. As a result, the heat transfer performance of the heat transfer unit 32 as a whole is improved, and as described above, the desired heat transfer performance can be ensured even when the flow velocity is relatively slow.

Further, according to the present embodiment, since the cutting angle of the plurality of louvers constituting the louver portion 50 is configured to be sequentially reduced toward the leeward side, the air becomes more downstream toward the downstream side of the louver portion 50. The flow angle becomes smaller (closer to the direction parallel to the surface of the heat transfer unit 32). As a result, the amount of air flowing between the louvers on the downstream side can be increased.

According to the present embodiment, air easily flows to the most downstream end region 32E (see FIG. 3) where the heat flux is relatively small on the other main surface 32b side of the heat transfer portion 32 in which the louver portion 50 is not provided. Therefore, the heat transfer performance in the region can be improved.

As described above, according to the present embodiment, the heat transfer performance of each heat transfer portion of the heat transfer fin 30 can be enhanced. This makes it possible to provide a heat exchanger having excellent heat exchange performance even when applied to a heat exchanger for refrigerating and air-conditioning applications in which the flow velocity of air is relatively slow.
Further, due to the configuration of the louver portion 50 described above, stable heat transfer performance can be ensured over almost the entire region of the heat transfer portion 32, so that the size is smaller than that of the conventional heat exchanger having the same heat transfer performance. It is possible to reduce the thickness.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made.

For example, in the above embodiment, the case where the heat transfer fin is a plate-shaped fin has been described as an example, but the present invention is not limited to this, and the present invention can be applied even when the heat transfer fin is a corrugated fin. Further, in the above embodiment, the parallel flow type heat exchanger has been described as an example, but the present invention is not limited to this, and the present invention also applies to fin tube heat exchangers formed by circular tubes and fins, plate fin heat exchangers, and the like. The invention is applicable.

Further, in the above embodiment, the louvers 51 to 56 constituting the louver portion 50 are formed so that the cut-up angles are different, but the cut-up angle and the height are the same among the plurality of louvers. A plurality of louvers may be arranged consecutively.

20 ... Heat transfer tube 21 ... Flow path 30 ... Heat transfer fin 32 ... Heat transfer section 40 ... Ventilation path 50 ... Louver section 51-56 ... Louver 61, 62 ... Tab 100 ... Heat exchanger

Claims (3)

A plurality of heat transfer tubes having a flow path through which the refrigerant flows along the first axial direction and arranged in the second axial direction orthogonal to the first axial direction,
A plurality of heat transfer fins arranged in the first axial direction and joined to the plurality of heat transfer tubes are provided.
The plurality of heat transfer fins have a heat transfer portion located between the plurality of heat transfer tubes and forming a ventilation path through which a fluid passes, and the heat transfer portion provided in the first axial direction and the second. Each has a louver portion including a plurality of louvers arranged in a third axial direction orthogonal to the axial direction.
The plurality of louvers have a certain height with respect to the heat transfer portion, and the plurality of louvers have a certain height.
A heat exchanger in which the cutting angle of the plurality of louvers with respect to the heat transfer portion gradually decreases from one end side to the other end side in the third axial direction. The heat exchanger according to claim 1.
A heat exchanger in which the arrangement pitch of the plurality of louvers gradually increases from the one end side toward the other end side. The heat exchanger according to claim 1 or 2.
The plurality of heat transfer fins are composed of plate-shaped fins having a plurality of tabs for adjusting the arrangement spacing of the plurality of heat transfer fins.
A part of the plurality of tabs is a heat exchanger provided on the other end side in the third axial direction with respect to the louver portion.

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