JPH09310989A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent durability and heat exchange performance by providing a plurality of corrugated fins provided vertically adjacent flat heat transfer tubes, forming an upper surface for constituting respective flat heat transfer tubes flat on the entire surface, and brazing many protrusions formed on the upper surface of the lower plate to the lower surface of an upper plate. SOLUTION: A flat heat transfer tube 15 assembled in a heat exchanger is formed by butting and brazing the connecting parts formed in the entire length at both lateral edges of band-like plate material 13 of aluminum alloy. In this case, many protrusions 1 are formed by roll molding at a plate material 13 on the upper surface of a lower plate 16 for constituting the tube 15. The upper end faces of the protrusions 17 are projected in contact with the lower surface of the upper pate 18 of the tube 15, and brazed. The heat exchanger is constituted by providing an inlet side header and an outlet side header at both right and left ends of a core formed of the tube 15 and corrugated fins 2 alternately disposed in the vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The heat exchanger according to the present invention is incorporated in an air conditioner for an automobile and used as a condenser for condensing and liquefying a high temperature, high pressure refrigerant gas discharged from a compressor.

[0002]

2. Description of the Related Art A heat exchanger having a core portion composed of a large number of fins and heat transfer tubes is known as a condenser constituting an automobile air conditioner. This heat exchanger is shown in FIG.
As shown in FIG. 2, the inlet pipe 5 is provided at both left and right ends of the core portion 3 including the flat heat transfer tubes 1 and 1 and the corrugated fins 2 and 2 which are alternately arranged in the horizontal direction and in the vertical direction.
And an outlet side header 8 having an outlet pipe 7. Further, side supports 4 and 4 are provided at both upper and lower end portions of the core portion 3 so as to reinforce the core portion 3 and to be used for attaching the heat exchanger to the vehicle body.

When the heat exchanger as described above is used, a fluid such as a refrigerant sent from the inlet pipe 5 to the inlet side header 6 and flowing in the flat heat transfer pipes 1, 1 is a flat heat transfer pipe forming the core portion 3. After being cooled by exchanging heat between the air flowing in the front-back direction of FIG. 4 between the 1 and 1 and the corrugated fins 2 and 2, it is sent out from the outlet pipe 7 through the outlet-side header 8.

In order to improve the performance of the heat exchanger as described above, the flow of a fluid such as a refrigerant flowing in the flat heat transfer tubes 1 and 1 is disturbed, and the fluid is brought into contact with the flat heat transfer tubes 1 and 1. It is effective to increase the area. Further, in order to ensure the pressure resistance of each flat heat transfer tube 1, 1, each flat heat transfer tube 1,
It is necessary to connect the upper plate portion and the lower plate portion that form 1 to each other at a plurality of locations. For this reason, the structure in which the inner fins are inserted inside the flat heat transfer tubes 1 and 1 constituting the heat exchanger and the inner fins are brazed to the lower surface of the upper plate portion and the upper surface of the lower plate portion is conventionally used. Used from.

However, it is troublesome to combine the separately prepared inner fins and the flat heat transfer tubes later, which causes the cost of the heat exchanger to be increased. In view of such circumstances, Japanese Utility Model Laid-Open No. 2-28986 discloses a flat heat transfer tube 1a as shown in FIG. This flat heat transfer tube 1a
Is a combination of elements 10a and 10b having protrusions 9a and 9b formed on the lower surface of the upper plate portion 18 and the upper surface of the lower plate portion 16 at positions aligned with each other, respectively, in the middle of the process. The contact surfaces are brazed to each other. The fluid such as the refrigerant flowing in the flat heat transfer tube 1a is disturbed by the presence of the projections 9a and 9b, so that the heat exchange efficiency between the fluid and the flat heat transfer tube 1a is improved. Further, since the tip surfaces of the plurality of projections 9a and 9b formed on the upper plate portion 18 and the lower plate portion 16 are brazed to each other, the upper plate portion is irrespective of the pressure increase in the flat heat transfer tube 1a. The distance between 18 and the lower plate portion 16 does not increase. Therefore, the pressure resistance of the flat heat transfer tube 1a can be sufficiently ensured.

[0006]

In the case of the flat heat transfer tube 1a having the above-described structure, the plurality of protrusions 9a and 9b are formed on both the elements 10a and 10b. Therefore, the flat heat transfer tube 1
Recesses 11a and 11b are formed on the upper and lower surfaces of a, respectively. Of these, foreign matters such as dust and water easily accumulate inside the recesses 11a and 11a formed in the upper surface of the upper plate portion 18 of the flat heat transfer tube 1a. For this reason, substances such as mud and snow-melting salt scattered from the road when the automobile is running are liable to be recessed in the recesses 11a, 11a.
Will be accumulated inside and will corrode the flat heat transfer tube 1a, which will cause the durability of the heat exchanger to be impaired.

Further, as shown in FIG. 6, the flat heat transfer tube 1a is
The upper and lower surfaces of the flat heat transfer tube 1a and the curved portions 12, 12 of the corrugated fins 2 do not come into contact with each other at the positions where the recesses 11a and 11b are formed on the upper and lower surfaces of the corrugated fin 2. Therefore,
As much as they are not in contact with each other, heat transfer from the flat heat transfer tube 1a to the corrugated fins 2 deteriorates, and the heat dissipation performance of the heat exchanger deteriorates. The heat exchanger of the present invention was invented in view of the above circumstances.

[0008]

The heat exchanger of the present invention, like the above-mentioned conventional heat exchanger, has a pair of left and right headers horizontally spaced from each other and vertically spaced from each other. A plurality of flat heat transfer tubes which are respectively arranged in the horizontal direction and have both end openings communicating with the headers, and a plurality of corrugated fins provided between vertically adjacent flat heat transfer tubes. With. In particular, in the heat exchanger of the present invention, among the upper plate portion and the lower plate portion that constitute each of the flat heat transfer tubes, the upper plate portion is flat over the entire surface, and the upper surface of the lower plate portion is Is formed with a large number of protrusions protruding toward the lower surface of the upper plate portion, and the tip surfaces of these protrusions and the lower surface of the upper plate portion are brazed to each other.

[0009]

In the heat exchanger of the present invention configured as described above, a large number of protrusions formed on the upper surface of the lower plate of the flat heat transfer tube disturb the fluid flowing along the inner surface of the flat heat transfer tube. In addition, the contact area of this fluid with the inner surface of the flat heat transfer tube is increased. Therefore, the heat exchange performance between the fluid and the flat heat transfer tube can be enhanced. Further, the large number of protrusions prevent the upper plate portion and the lower plate portion of the flat heat transfer tube from separating from each other, thereby improving the pressure resistance of the flat heat transfer tube. Further, in the case of the heat exchanger of the present invention, since the upper plate portion of the flat heat transfer tube is flat over the entire surface, there is a substance that corrodes the flat heat transfer tube such as mud or snow melting salt scattered from the road when the vehicle is running. , It is hard to collect on the upper surface of the upper plate portion. Further, since the upper plate of the flat heat transfer tube is flat over the entire surface, a sufficient contact area between the upper surface of the upper plate and the curved portion of the corrugated fin can be secured. As a result, the heat transfer between the flat heat transfer tube and the corrugated fin is improved, and the heat dissipation performance of the heat exchanger as a whole can be improved.

[0010]

1 to 3 show an example of an embodiment of the present invention. The feature of the present invention lies in the structure and operation of the flat heat transfer tube 15 that constitutes the core portion 3 (see FIG. 4) together with the corrugated fins 2. Since the structure and operation of the other parts are the same as those of the conventional structure described above, redundant description will be omitted or simplified, and the characteristic part of the present invention will be mainly described below.

The flat heat transfer tube 15 incorporated in the heat exchanger of the present invention is formed by roll-forming a strip-shaped plate material 13 made of an aluminum alloy. That is, the above-mentioned plate material 1 is accompanied by roll forming.
After the joint portions 14a and 14b are formed on both end edges in the width direction of 3 over the entire length of the plate member 13, both joint portions 14 are formed.
The flat heat transfer tube 15 is formed by abutting and brazing the a and 14b against each other.

The brazing of the joints 14a and 14b is performed at the same time as the brazing of the members constituting the heat exchanger with the flat heat transfer tube 15. Therefore, the plate material 13 is a so-called double-sided clad material in which a brazing material is laminated on both surfaces of a core material. Further, a large number of protrusions 17 and 17 are formed on the upper surface of the lower plate portion 16 constituting the flat heat transfer tube 15 by performing the above-described roll forming on the plate material 13. As shown in FIG. 2, each of these protrusions 17, 17 is
The flat heat transfer tubes 15 are arranged in a staggered manner on the lower plate portion 16 so as not to form parallel flow paths extending in the axial direction. And
The upper end surface of each of these protrusions 17 and 17 has the flat heat transfer tube 1 described above.
5 is abutted against the lower surface of the upper plate portion 18, and the abutted portion is brazed and joined. Of course, this brazing is also performed at the same time as brazing the constituent parts of the heat exchanger.

When a heat exchanger of the present invention incorporating the flat heat transfer tube 15 as described above is used, when a fluid such as a refrigerant is circulated in the flat heat transfer tube 15, this fluid causes the projections 17,
The flow is disturbed by 17, and the contact area between this fluid and the inner surface of the flat heat transfer tube 15 increases. Therefore,
The heat transfer efficiency between the fluid and the flat heat transfer tube 15 is improved, and the heat dissipation performance of the heat exchanger incorporating the flat heat transfer tube 15 can be improved. In addition, each of the above-mentioned protrusions 17, 17
However, the lower plate portion 16 and the upper plate portion 18 are prevented from separating from each other, and the pressure resistance of the flat heat transfer tube 15 is secured.

On the lower surface of the lower plate portion 16 of the flat heat transfer tube 15, the projections 17 and 17 are formed on the upper surface of the lower plate portion 16.
The concave portions 19 and 19 are formed along with the formation of
The upper surface of the upper plate portion 18 of the flat heat transfer tube 15 remains a flat surface. Therefore, a substance that corrodes the flat heat transfer tube 15 such as mud or snow melting salt scattered from the road when the vehicle is running is
It is hard to collect on the upper surface of the upper plate portion 18. As a result, the corrosion resistance of the flat heat transfer tube 15 can be sufficiently ensured.

Further, as shown in FIG. 3, the flat heat transfer tube 1 is used.
Regarding the contact portions between the upper and lower surfaces of 5 and the curved portions 12, 12 of the corrugated fins (see FIG. 4), a sufficient contact area can be secured at the upper surface portion of the upper plate portion 18 of the flat heat transfer tube 15. . Therefore, heat transfer between the flat heat transfer tubes 15 and the corrugated fins 2 is ensured, and both members 1
It is possible to improve the performance of the heat exchanger incorporating the elements 5 and 2.

[0016]

Since the heat exchanger of the present invention is constructed and operates as described above, the heat exchange between the fluid flowing in the flat heat transfer tube and the flat heat transfer tube can be performed without lowering the corrosion resistance of the flat heat transfer tube. Not only can the heat transfer efficiency be improved and the pressure resistance of the flat heat transfer tube can be secured, but also the heat transfer performance between the flat heat transfer tube and the corrugated fins can be improved. Therefore, a heat exchanger having excellent durability and heat exchange performance can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a flat heat transfer tube as seen from above, showing an example of an embodiment of the present invention.

FIG. 2 is a perspective view of the same seen from below.

FIG. 3 is a schematic partial vertical cross-sectional view of a core portion in the heat exchanger of the present invention.

FIG. 4 is a schematic perspective view showing an example of a conventionally known heat exchanger.

FIG. 5 is a partial perspective view showing an example of a conventionally known flat heat transfer tube.

FIG. 6 is a view similar to FIG. 3 in the conventional product.

[Explanation of symbols]

 1, 1a Flat heat transfer tube 2 Corrugated fins 3 Core part 4 Side support 5 Inlet tube 6 Inlet side header 7 Outlet tube 8 Outlet side header 9a, 9b Protrusion 10a, 10b Element 11a, 11b Recess 12 Curved portion 13 Plate material 14a, 14b Joint part 15 Flat Heat Transfer Tube 16 Lower Plate 17 Protrusion 18 Upper Plate 19 Recess

Claims (1)

[Claims] 1. A pair of left and right headers horizontally spaced apart from each other, and a pair of headers horizontally spaced apart vertically from each other, and opening both ends of each header into the respective headers. In a heat exchanger comprising a plurality of flat heat transfer tubes and a plurality of corrugated fins provided between vertically adjacent flat heat transfer tubes, an upper plate portion constituting each of the flat heat transfer tubes, Of the lower plate part, the upper plate part is flat over the entire surface, and a large number of projections projecting toward the lower surface of the upper plate part are formed on the upper surface of the lower plate part. A heat exchanger characterized in that a tip surface and a lower surface of the upper plate portion are brazed to each other.