JPH0688689A - Method for manufacturing heat exchanger for air conditioning operation and heat exchanger - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a heat exchanger for an air conditioning operation and the like in which a superior heat transfer can be attained, a better machining or a better connecting characteristics can be attained and its manufacturing can be performed in a relative less expensive cost irrespective of the fact that thermal medium other than fluorocarbon can be used. CONSTITUTION:A thermal medium pipe 1 is made of stainless steel. Protrusions or recesses 2 or 3 in their radial directions are formed in an axial direction of the pipe. In turn, plate fins 10 are made of aluminum so as to form a collar 11 to be fitted to the thermal medium pipe 1. The collar 11 of the plate fins is press fitted to the thermal medium pipe 1 in such a manner that the surface of the thermal medium pipe 1 is covered by the collar 11 and the plate fins 10 are fixed to the thermal medium pipe 1. The collar 11 of the plate fins and the adjoining plate fins 10 are connected to each other and also the thermal medium pipe 1 and the collar 11 of the plate fins are connected to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heat exchanger for air conditioning and the like, and a heat exchange, which is composed of a heat medium pipe through which a heat medium flows and fins press-fitted into the outer peripheral portion of the heat medium pipe. It is related to vessels.

[0002]

2. Description of the Related Art A heat exchanger for a room air conditioner, a car air conditioner or the like generally comprises a group of plate fins arranged at predetermined intervals and a heat medium pipe penetrating the group of fins. Therefore, when freon, which is a heat medium, is caused to flow through the heat medium pipe and air is blown between the plate fins, heat is exchanged between the heat medium and air through the fins,
The air can be heated or cooled and conditioned. The heat transfer medium pipe used in such a heat exchanger is generally formed of an alloy such as copper, aluminum or the like which has good heat conduction and is easy to work. By the way, among the CFCs that have been used so far, they are chemically extremely stable and difficult to decompose, and are excellent as a heat medium, but they have a fatal defect of destroying the ozone layer, which is a problem of the global environment. Therefore, it is almost certain that CFCs cannot be used in the future. Ammonia and water are regarded as promising alternatives to CFCs.
It has the drawback of corroding heat transfer tubes such as aluminum,
Ammonias are also harmful to the human body.

[0003]

[Problems to be Solved by the Invention]
For a corrosive heat medium such as water, it is possible to form the heat medium pipe with stainless steel, but stainless steel is copper,
Since heat transfer is lower than that of aluminum or the like, there is a practical problem even if a heat transfer medium pipe made of stainless steel is applied instead of the heat transfer medium pipe of copper, aluminum or the like. Further, there is a problem of workability or joining between dissimilar metals, which is expected to increase the cost. Furthermore, there is a danger to the human body due to the leakage of ammonia. The present invention has been made in view of the recent circumstances as described above, and although heat medium other than CFC can be used, heat transfer is good,
It is an object of the present invention to provide a method for manufacturing a heat exchanger for air conditioning and the like, which has good workability or bondability and can be manufactured at a relatively low cost.

[0004]

In order to achieve the above-mentioned object, the present invention forms a heat transfer medium pipe made of stainless steel having concave and convex lines in the radial direction in the pipe axis direction, while aluminum or its Forming a plate fin having a collar that fits into the heat transfer medium pipe from an alloy, and pressing the plate fin collar into the heat transfer medium pipe to attach the plate fin to the heat transfer medium pipe, The invention is configured so that the outer surface is covered with the collar of the plate fin without any gaps, and the invention according to claim 2 forms a heat transfer pipe made of stainless steel having a radial concave and convex in the pipe axial direction. On the other hand, a plate fin having a collar that fits into the heat transfer medium pipe is formed from aluminum or its alloy, and the collar of the plate fin is press-fitted into the heat transfer medium pipe to heat the heat transfer medium. When attaching the plate fins to the pipes, the heat transfer pipes are mounted so that the outer surfaces of the heat transfer pipes are covered with the collars of the plate fins without gaps, and at least the tip of the collar of the plate fins and the adjacent plate fins are brazed. It is configured to join by contact.
The invention according to claim 3 is composed of a heat transfer medium pipe made of stainless steel having radial concaves and convexes in the pipe axis direction, and a plate fin made of aluminum or its alloy press-fitted into the heat transfer medium pipe. The outer surface of the heat transfer medium pipe is covered with the collar of the plate fin, and the invention according to claim 4 is such that at least the tip of the collar of the plate fin made of aluminum or its alloy is adjacent to the plate fin. It is joined by brazing.

[0005]

Since the invention of the heat exchanger according to claim 3 is configured as described above, the heat medium, for example, an ammonia is flown through the heat medium pipe made of stainless steel. On the other hand, air is blown between the plate fins made of aluminum or its alloy. Then, heat is exchanged between the heat medium and the air, and the air is heated or cooled. At this time, since the concave and convex ridges in the radial direction are formed in the tube axial direction on the heat transfer medium pipe made of stainless steel, the heat transfer area is widened and a large amount of heat is transferred. The invention of the heat exchanger according to claim 4 is
In addition to acting as described above, since the tip of the collar of the plate fin is joined to the adjacent plate fin by brazing, the heat medium pipe has a double pipe structure, and when the heat medium leaks from the heat medium pipe. , Exits through between the outer surface of the heat transfer tube and the inner surface of the collar of the plate fin. Take appropriate action by detecting this.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In carrying out the present invention, a fin made of stainless steel is brazed to the surface of a plate fin made of aluminum or its alloy located at the end when assembled as a heat exchanger. Is desirable. This is because when a stainless steel bend, a piping pipe, or the like is brazed to the end of the heat transfer medium pipe with a torch, the flame of the torch can be prevented from directly contacting the aluminum plate fins, and the plate fins can be prevented from melting. Further, the plate fin made of aluminum or its alloy, which is inferior in strength when the heat exchanger hits the object, is also protected by the fin made of stainless steel.

An embodiment of the present invention will be described below. Figure 1
As shown in (a) of item (a), the heat exchanger H according to the present embodiment has the same external appearance as the conventional one.
That is, the plate fins 10 arranged at predetermined intervals,
.. and heat medium pipes 1, 1, ... Penetrating the fins 10, 10 ,. The plate fin 10 is made of aluminum or its alloy, and the heat transfer medium pipe 1 is made of stainless steel. The heat transfer medium pipe 1 is formed by bending a stainless steel plate so that its cross section has a pulse wave shape or a concave line 2 and a convex line 3, and the concave and convex lines 2 and 3 are in the longitudinal direction. It is formed by welding the end edge to. In this way, as shown in (b) of FIG. 1, on the inner and outer surfaces of the heat transfer medium pipe, the heat transfer medium pipe in which the concave and convex ridges 2 and 3 are formed in a predetermined length in the pipe axis direction. 1 is obtained. It is obvious that the heat medium tube 1 can be formed by another processing method.

As shown in FIG. 1C, the collars 11, 11, ... Are arranged in the same direction on the plate fin 10 made of aluminum or its alloy having a substantially rectangular shape in the same direction. Correspondingly, a plurality is formed at predetermined intervals. The collar 11 is a part fitted to the heat medium tube 1,
The length in the axial direction is set to the interval between the plate fins 10 and 10.

Next, the assembly will be described. Collar 11 of plate fin 10 made of aluminum or its alloy
2 are press-fitted into the stainless steel heat transfer medium pipe 1 in the same direction without any gap, as shown in FIG. That is, the tip of the collar 11 of the plate fin 10 is adjacent to the plate fin 1
Press it into contact with 0. Although not shown in the figure, a stainless steel bend pipe, pipe, etc. are flame brazed by a torch to the portion where the heat medium pipe 1 is exposed from the group of plate fins 10 to finish the assembly. According to this embodiment, the heat exchanger can be manufactured at low cost simply by press-fitting the collar 11 of the plate fin 10 into the heat transfer medium pipe 1 made of stainless steel. Moreover, the manufactured heat exchanger has concave, convex stripes 2,
Since 3 is formed, the surface area is large for the pipe diameter,
The heat transfer is great.

Next, the second assembling method of brazing will be described. A zinc chloride reaction brazing method can also be applied to the joining of the heat transfer pipe 1 made of stainless steel and the collar 11 of the plate fin 10 made of aluminum or its alloy, which is shown in, for example, JP-A-63-93471. A brazing method using a fluoride-based flux will be described. A fluoride flux containing tin fluoride in an amount of 0.05 to 15 wt% is applied to the outer surface of the heat transfer medium tube 1 made of stainless steel. Then, as shown in FIG. 2, the collar 11 of the plate fin 10 is connected to the heat transfer tubes 1, 1, ...
Insert in the same direction without gaps. Then, the brazing material made of an Al-Si alloy is melted and brazed in a non-oxidizing atmosphere to braze the heat transfer medium pipe 1 made of stainless steel and the collar 11 of the plate fin 10 made of aluminum or its alloy. Contact. At this time, color 1 of plate fin 10
The tip end of 1 and the surface of the adjacent plate fin 10 are also brazed. According to this embodiment, the collar of the plate fin made of aluminum at the time of brazing and the heat medium made of stainless steel are made by the spring effect of the concave and convex stripes 2, 3 of the heat medium pipes 1, 1, ... Made of stainless steel. Differences in thermal expansion between the tubes can also be absorbed. By this brazing, the heat transfer medium pipe 1 has a double pipe structure, the risk of leakage of ammonia that is harmful to the human body is eliminated, and the heat conduction between the heat transfer medium pipe 1 and the plate fin 10 is improved.

[0011]

As described above, according to the present invention, the heat transfer medium pipe made of stainless steel is formed with the concave and convex lines in the axial direction of the pipe, so that it has a spring effect and is made of aluminum or its alloy. The plate fin collar can be easily attached to the heat medium pipe by a press-fitting method, and there is no need to expand the diameter after inserting the collar as in the conventional case, and the effect peculiar to the present invention can be obtained at low cost. According to the second aspect of the invention, due to the spring effect of the heat transfer medium pipe made of stainless steel, the adhesion to the plate fin collar is good, and the aluminum plate fin collar at the time of brazing and the stainless steel heat transfer medium. The difference in thermal expansion between the pipe and the pipe can be absorbed, and the brazing work is simplified. Further, the heat transfer medium pipe of the heat exchanger of the present invention,
Since it is composed of stainless steel, a corrosive heat carrier other than CFC can be used. In addition, since the heat medium tube is formed with the concave and convex lines, the surface area is large relative to the diameter of the tube, and heat transfer can be improved especially when the heat medium is in the vapor phase state. Therefore, it is optimal as a heat exchanger for air conditioning. According to the invention described in claim 4, since the outer periphery of the heat transfer medium pipe is covered with the collar of the plate fin and is brazed, the heat transfer medium pipe has a complete double pipe structure, which is harmful in addition to the above effect. It is possible to prevent the leakage of various refrigerants. Even if a hole leaks into the heat transfer medium pipe, the pipe has a double pipe structure, that is, there are a plurality of grooves in the axial direction between the outer periphery of the heat transfer medium pipe and the inner surface of the collar. Since it is formed, it comes out from the end through these grooves, so this can be easily detected and safety measures are inexpensive.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention, (a) is a perspective view showing an example of a heat exchanger, (b) is a heat medium pipe, and (c) is an example of a plate fin. It is a perspective view showing each.

FIG. 2 is a front view showing a part of a state in which a plate fin collar is press-fitted into a heat medium pipe.

FIG. 3 is a plan view showing a part of a state in which the plate fins of the plate fins are press-fitted into the heat medium pipe and brazed to each other.

[Explanation of symbols]

 1 Heat medium pipe 2 Recessed strip 3 Convex strip 10 Plate fin 11 Color

Claims (4)

[Claims] 1. A heat transfer medium pipe made of stainless steel having radial concaves and convex lines in the pipe axis direction is formed, while a plate fin having a collar fitted to the heat transfer medium pipe is formed from aluminum or an alloy thereof. And, when the plate fin collar is press-fitted into the heat medium pipe to attach the plate fin to the heat medium pipe, the outer surface of the heat medium pipe is attached without a gap so as to be covered with the plate fin collar. A method for manufacturing a heat exchanger for air conditioning, which is characterized in that 2. A heat transfer medium tube made of stainless steel having radial concaves and convexes in the tube axis direction is formed, while a plate fin having a collar fitted to the heat transfer medium tube is formed from aluminum or an alloy thereof. And, when the plate fin collar is press-fitted into the heat medium pipe to attach the plate fin to the heat medium pipe, the outer surface of the heat medium pipe is attached without a gap so as to be covered with the plate fin collar. Then, at least a collar fin of the plate fin and an adjacent plate fin are joined by brazing, which is a method for manufacturing a heat exchanger for air conditioning or the like. 3. A heat transfer medium pipe made of stainless steel having radial concaves and convexes in the axial direction of the pipe, and a plate fin made of aluminum or an alloy thereof press-fitted into the heat transfer medium pipe. The heat exchanger for air conditioning or the like, wherein the outer surface of the medium pipe is covered with the collar of the plate fin. 4. A heat exchanger for air conditioning or the like, wherein at least a tip portion of the collar of the plate fin made of aluminum or its alloy according to claim 3 is joined to an adjacent plate fin by brazing.