JP2013092265A - Heat exchanger, fin for the same, and method for manufacturing of heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger that can fix a fin and a heat transfer tube using adhesive while maintaining adhesiveness of an initial stage of assembling a heat release fin and the heat transfer tube, and to provide a fin for the heat exchanger and a method for manufacturing of the heat exchanger.SOLUTION: The heat exchanger 100 includes: the heat transfer tube 2 and a fin 3 for exchanging heat between medium passed through the heat transfer tube 2 which is perpendicularly attached to the axis direction of the heat transfer tube 2. The fin 3 has an opening 32 to attach the heat transfer tube 2, and a part surrounding the heat transfer tube 2 of an edge of the opening 32 has a fin collar 33 projecting to the axis direction of the heat transfer tube 2. The fin collar 33 and the heat transfer tube 2 are temporary fastened by welding.

Description

  The present invention relates to a heat exchanger, a fin for a heat exchanger, and a method for manufacturing a heat exchanger.

As a method of joining the fin and the circular heat transfer tube in the fin-tube heat exchanger, by inserting the heat transfer tube into the hole provided in the fin, applying pressure from the inside of the heat transfer tube to the outside, and expanding the tube, The most common method is a tube expansion method in which fins and heat transfer tubes are brought into close contact with each other.
However, in order to improve the performance of the heat exchanger, if a flat tube is used instead of a circular tube as the heat transfer tube, the tube expansion method cannot be adopted for reasons of processing technology or manufacturing cost.

Therefore, in a heat exchanger using a flat tube, conventionally, a brazing method has been adopted for joining the flat tube and the radiating fin.
However, if a brazing method is used as a method for joining flat tubes and fins in a flat tube heat exchanger for indoor units, the manufacturing cost will increase significantly.
That is, it is necessary to coat the surface of the fin of the heat exchanger for indoor units with a hydrophilic film in order to prevent water droplets condensed on the fin surface from jumping out from the blower opening of the product (dew jump).

When joining flat tubes and fins by brazing, the melting temperature of the brazing material is higher than the melting temperature of the hydrophilic film, so there is a post-coating process that applies a hydrophilic film to the fin surface after brazing. Necessary.
This is a significant increase in the number of manufacturing processes compared to the processing method in which a fin film used in a circular tube heat exchanger is first coated with a hydrophilic film and the pre-coated board is pressed to form the fin shape. Increase in manufacturing costs.

For this reason, in flat tube heat exchangers for indoor units that require a hydrophilic film particularly on the fin surface, heat treatment is not required for joining the flat tube and the fin, or the melting and curing temperature is a hydrophilic film. A method using an adhesive having a temperature lower than the melting temperature is used.

  As such a known technique, a method has been proposed in which a tube material is inserted into a fin from an opening, a heat transfer tube is caulked, and then a coating film is formed in a gap between the fin and the heat transfer tube (for example, Patent Document 1).

  Moreover, the technique as described in patent document 2 is proposed as a method of joining a fin and a heat exchanger tube by welding by electrical resistance welding.

JP 09-145282 A Sho 61-106783

However, when an adhesive is used for fixing the heat transfer tube and the fin, the following problems have occurred.
Since the thermal conductivity of the adhesive is lower than that of the brazed metal bond, in order to obtain a high heat exchange rate, it is necessary to improve the adhesion between the fin and the heat transfer tube.
Therefore, in Patent Document 1, a coating film is used, but as a pretreatment for coating, the fin is attached to the heat transfer tube and the straight tube portion of the heat transfer tube is crimped so that the fin does not move during the coating. Temporarily fixed. (Paragraph 0038)
When the heat transfer tube is deformed by such a method, there is a problem that the adhesion between the fin and the heat transfer tube is greatly reduced in the deformed portion.

Further, when a flat tube is employed as the heat transfer tube, the heat transfer tube mounting portion of the fin is U-shaped, and one side is an open hole, there are further problems as follows.
That is, in order to make the fin collar provided at the heat transfer tube mounting portion of the fin and the heat transfer tube tightly contact, it is necessary to crimp the flat heat transfer tube from both ends in the longitudinal direction of the cross section while pressing the fin collar against the flat heat transfer tube. is there.
The fins are distorted by the pressing load and the caulking load.
Due to this distortion, the phenomenon that the flat heat transfer tube shifts to the outside of the fin heat transfer tube opening occurs, and the adhesion between the fin collar and the flat heat transfer tube at the U-shaped closed end of the fin opening is impaired. There was a problem.

  Furthermore, after assembling the fin and the flat heat transfer tube, until the adhesive is applied and cured, the fin and the flat heat transfer tube are not fixed. When a disturbance such as an external load is applied, the flat heat transfer tube is displaced at the heat transfer tube mounting portion of the fin, and the adhesion between the fin collar and the flat heat transfer tube at the U-shaped closed end is impaired. There was a problem.

  The present invention has been made to solve these problems, and is capable of fixing the fin and the heat transfer tube with an adhesive while maintaining the initial adhesion between the fin and the heat transfer tube. It aims at providing the manufacturing method of a fin for equipment and a heat exchanger.

The heat exchanger according to the present invention is
A heat transfer tube,
In the heat exchanger having a fin that is attached to the heat transfer tube in a direction perpendicular to the axial direction of the heat transfer tube and exchanges heat between the medium passing through the heat transfer tube and the outside air,
The fin has an opening for mounting on the heat transfer tube,
In the part surrounding the heat transfer tube at the edge of the opening, it has a fin collar protruding in the axial direction of the heat transfer tube,
The fin collar and the heat transfer tube are temporarily fixed by welding.

Moreover, the fin for the heat exchanger according to the present invention is
In the heat exchanger fin that is attached to the heat transfer tube in a direction perpendicular to the axial direction of the heat transfer tube and exchanges heat between the medium passing through the heat transfer tube and the outside air,
The fin has an opening for mounting on the heat transfer tube, and has a fin collar protruding in the axial direction of the heat transfer tube in a portion surrounding the heat transfer tube of the opening,
The fin collar further has a welding protrusion that protrudes in the axial direction of the heat transfer tube.

Moreover, the manufacturing method of the heat exchanger according to the present invention includes:
A heat transfer tube,
In the method of manufacturing a heat exchanger, the heat transfer tube includes a fin that is mounted in a direction perpendicular to the axial direction of the heat transfer tube and that exchanges heat between the medium passing through the heat transfer tube and the outside air.
The fin has an opening for mounting on the heat transfer tube,
The edge of the opening has a fin collar that projects in the axial direction of the heat transfer tube,
A fin mounting step for mounting the fin in the opening so that the fin collar is in close contact with the heat transfer tube;
A fin collar and a welding process for temporarily fixing the heat transfer tube;
It has a fin collar and a bonding process for bonding and fixing the heat transfer tube.

The heat exchanger according to the present invention is
The fin has an opening for mounting on the heat transfer tube,
In the part surrounding the heat transfer tube at the edge of the opening, it has a fin collar protruding in the axial direction of the heat transfer tube,
Since the fin collar and the heat transfer tube are temporarily fixed by welding,
The gap between the fin and the heat transfer tube does not widen during the fin mounting process, and good heat transfer performance can be exhibited.

Moreover, the fin for the heat exchanger according to the present invention is
, Having an opening for mounting on the heat transfer tube, and having a fin collar protruding in the axial direction of the heat transfer tube in a portion surrounding the heat transfer tube of the opening,
Since the fin collar further has a welding protrusion that protrudes in the axial direction of the heat transfer tube, there is a margin in the positioning accuracy of the place to be welded, and the workability of welding is improved.

Moreover, the manufacturing method of the heat exchanger according to the present invention includes:
The fin has an opening for mounting on the heat transfer tube,
The edge of the opening has a fin collar that projects in the axial direction of the heat transfer tube,
A fin mounting step for mounting the fin in the opening so that the fin collar is in close contact with the heat transfer tube;
A fin collar and a welding process for temporarily fixing the heat transfer tube;
Since it has a fin collar and a bonding process for bonding and fixing the heat transfer tube, the fin opening can be temporarily fixed to a predetermined position of the heat transfer tube by temporary fastening welding, and good adhesion between the fin and the heat transfer tube can be obtained. The heat transfer tube and fin bonding step can be performed while maintaining the initial state.

It is a perspective view of the heat exchanger which concerns on Embodiment 1 of this invention. It is a principal part perspective view of the heat exchanger fin which concerns on Embodiment 1 of this invention. It is a principal part enlarged view of the heat exchanger tube for heat exchangers which concerns on Embodiment 1 of this invention. It is an enlarged view of the attachment part vicinity to the heat exchanger tube of the fin which concerns on Embodiment 1 of this invention. It is an enlarged view of the attachment part vicinity to the heat exchanger tube of the fin which concerns on Embodiment 2 of this invention. It is an enlarged view of the attachment part vicinity to the heat exchanger tube of the fin which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
Hereinafter, the manufacturing method of the heat exchanger which concerns on Embodiment 1 of this invention, the fin for heat exchangers, and a heat exchanger is demonstrated using figures.
FIG. 1 is a schematic perspective view of a fin-tube heat exchanger 100 (hereinafter referred to as a heat exchanger 100).
FIG. 2 is a schematic perspective view of the fin 3 for the heat exchanger 100.
FIG. 3 is an enlarged view of a main part of the heat transfer tube 2 for the heat exchanger 100.
As shown in FIG. 1, the heat exchanger 100 includes a fin 3 formed in a strip shape on a flat heat transfer tube 2 piped in a ladder shape with a predetermined interval DP between two distribution pipes 1. Are mounted at a predetermined interval FP.

The end of the heat transfer tube 2 is joined to the distribution pipe 1 by brazing. The heat transfer tubes 2 and the fins 3 are temporarily joined by welding and then joined by an adhesive.
The refrigerant flows into the heat transfer tube 2 through the distribution pipe 1 to exchange heat between the fins 3 and the outside air.

As a material of the fin 3 shown in FIG. 2, a thin plate having a thickness of 0.09 to 0.2 mm mainly made of aluminum or an aluminum alloy is used.
The surface of the thin plate is preferably preliminarily subjected to surface film treatment for the purpose of anticorrosion, antifouling, hydrophilicity or water repellency.

The base surface 31 of the fin 3 is provided with an opening 32 for mounting the fin 3 on the heat transfer tube 2 with a predetermined distance DP in the longitudinal direction of the fin 3.
The opening 32 has a shape that roughly follows the outer peripheral surface of the heat transfer tube 2 and has a notch shape that is open at one end, and a fin collar 33 is formed along the periphery thereof.
The fin collar 33 is formed integrally with the fin 3 from the above-described thin plate, and is provided to improve the adhesion between the heat transfer tube 2 and the fin 3 and improve the heat exchange efficiency.

Between the adjacent openings 32 of the fin 3, heat radiation plates 34 and 35 are cut and raised from the base surface 31 of the fin 3.
Two opposing sides of the heat sinks 34 and 35 (upper and lower sides in FIG. 2) are cut from the base surface 31 to form a slit 36.
The height at which the heat radiating plates 34 and 35 are cut and raised from the base surface 31 is preferably about half of the arrangement interval FP of the fins 3.

It is desirable that the height of the fin collar 33 from the base surface 31 is substantially the same as the FP within a range not exceeding the value of the interval FP between the plurality of fins 3 to be mounted.
By making the height of the fin collar 33 from the base surface 31 sufficiently high as long as it does not exceed the value of FP, the contact area between the fin 3 and the heat transfer tube 2 can be widened, and heat transfer performance is improved. can do.
The value of FP is determined by the characteristics of the heat exchanger, but is generally about 1.0 mm to 2.0 mm.

As shown in FIG. 3, the heat transfer tube 2 has a flat shape in which a cross section perpendicular to the longitudinal direction has a substantially oval shape, and includes an arcuate R portion 21 having a short side and a flat portion 22 having a long side. The outline is configured.
Further, it is a multi-hole tube having a partition wall 23 inside.
By using the multi-hole tube, it is possible to increase the contact area between the inner surface of the heat transfer tube 2 and the refrigerant flowing inside, and the heat exchange efficiency can be improved.
The material of the heat transfer tube 2 is mainly aluminum or an aluminum alloy, and is formed by a processing method such as extrusion or pultrusion.

FIG. 4 is an enlarged view of the vicinity of the attachment portion of the fin 3 to the heat transfer tube 2.
The heat exchanger 100 is first assembled by a fin mounting process in which the fins 3 are inserted into the heat transfer tubes 2 connected to the distribution pipes 1.
At the time of assembly, the fins 3 are assembled in such a posture that the openings 32 open downward.
Immediately after the assembly, the adhesion between the fin collar 33 and the heat transfer tube 2 is kept good.
Therefore, following the fin mounting process, the next welding process is performed in the same posture.
In the welding process, the heat transfer tube 2 is prevented from being displaced from the opening 32 of the fin 3 by metal-bonding the fin 3 and the heat transfer tube 2 by spot welding, laser welding or the like at the welded portion 13.
It is desirable that the number of welding points 13 be at least one for one fin collar 33, and it is particularly desirable to weld the fin collar center top 33a.
The fin collar side surface portion 33b which is the side surface of the fin collar 33 may also be welded at about 1 to 4 points.
The area to be welded is a narrow area of about φ0.5 mm to φ2.0 mm, and it is sufficient that the fin 3 and the heat transfer tube 2 can be temporarily fixed.

By the temporary fastening by the welding process, the opening 32 of the fin 3 is temporarily fixed at a predetermined position of the heat transfer tube 2, and an initial state having good adhesion can be maintained.
Although the opening 32 has a shape having an open end, the heat transfer tube 2 can be prevented from coming out to the outside by temporary fastening welding.
Therefore, in the next bonding step, the heat exchanger 100 is re-installed so that the opening 32 of the fin 3 is on the upper side, and an adhesive is injected into the gap between the fin collar 33 and the heat transfer tube 2 from the open end side. An adhesive layer is formed in the gap, and both members are completely fixed.

According to the heat exchanger, the heat exchanger fin, and the heat exchanger manufacturing method according to Embodiment 1 of the present invention, the innermost fin collar of the opening 32 for mounting the fin 3 to the heat transfer tube 2 Good adhesion between the heat transfer tube 2 and the fin collar 33 can be secured at the central top 33a.
Thereby, the heat exchanger 100 which has the expected heat-conducting performance can be obtained.

  Moreover, if the fin 3 and the heat transfer tube 2 are metal-bonded by welding at a plurality of locations, the thermal conductivity between the fin 3 and the heat transfer tube 2 is improved, and the heat exchange performance is further increased.

Further, the opening 32 has a shape having an open end. However, since the heat transfer tube 2 can be prevented from coming outside by temporary welding, the fin 3 and the heat transfer tube 2 are welded, and then the open end side of the fin 3. The heat exchanger 100 is installed with the upper side facing upward, and the adhesive can be easily injected into the gap between the fin 3 and the heat transfer tube 2.
Thereby, an adhesion process can be implemented by an easy method.

  Further, even before the adhesive is completely cured, the fin 3 and the heat transfer tube 2 are temporarily fixed by welding, so that the close relationship between the fin 3 and the heat transfer tube 2 even if the heat exchanger 100 is moved. Will not be damaged.

  In the present embodiment, the example in which the fins 3 are attached to the heat transfer tube 2 one by one has been shown. May be.

Embodiment 2. FIG.
Hereinafter, the manufacturing method of the heat exchanger, the heat exchanger fins, and the heat exchanger according to the second embodiment of the present invention will be described with reference to the drawings, focusing on the differences from the first embodiment.
FIG. 5 is an enlarged view of the vicinity of a portion where the fin 203 is attached to the heat transfer tube 2.
The heat exchanger according to the present embodiment is the same fin-tube heat exchanger as in the first embodiment, and the fin 203, the heat transfer tube 2, and the distribution pipe 1 are configured in the same manner as in the first embodiment. .

The fin collar 233 includes a protruding portion 233c and a protruding portion 233d that protrude outward from the fin collar center top portion 233a and the fin collar side surface portion 233b.
These protrusions 233c and 233d are provided at one location on the fin collar central top portion 233a and about 1 to 4 locations on the fin collar side surface portion 233b, and the amount of protrusion in the axial direction of the heat transfer tube 2 is arranged at the front and rear. This is an amount that does not interfere with the fins 203.
When welding the fin collar 233 to the heat transfer tube 2, if spot welding is employed, the electrodes are brought into contact with the protruding portions 233 c and 233 d for welding.

According to the heat exchanger, the heat exchanger fin, and the heat exchanger manufacturing method according to Embodiment 2 of the present invention, by providing the protrusions 233c and 233d, the contact area of the electrode can be increased, and more It becomes possible to perform welding firmly.
In addition, since there is a margin in positioning accuracy when the electrodes are brought into contact with each other, there is an advantage that workability in the welding process is improved.

Similarly, when laser welding is employed, a large welding area can be secured, so that it is possible to maintain good adhesion between the fins 203 and the heat transfer tubes 2 by performing stronger temporary fixing. It becomes.
Furthermore, since the laser irradiation position accuracy is afforded, the welding workability can be improved.

Embodiment 3 FIG.
Hereinafter, the manufacturing method of the heat exchanger, the heat exchanger fin, and the heat exchanger according to the third embodiment of the present invention will be described with reference to the drawings, focusing on the differences from the first embodiment.
FIG. 6 is an enlarged view of the vicinity of the attachment portion of the fin 3 to the heat transfer tube 2.
The heat exchanger according to the present embodiment is the same fin-tube heat exchanger as in the first embodiment, and the fins 3, the heat transfer tubes 2, and the distribution pipes 1 are configured in the same manner as in the first embodiment. .

As shown in FIG. 6, the base surface 31 of the fin 3 is sandwiched between a plurality of heat transfer tubes 2 arranged at equal intervals, but the base of the fin 3 located outside the heat transfer tubes 2 at both ends. As for the surface 31, one side is an open end and is not configured to be sandwiched between the heat transfer tubes 2.
For this reason, the adhesion between the fin collar center top portion 33a located at both ends of the fin 3 and the heat transfer tube 2 becomes the worst, and when the fin is deformed in the direction in which the adhesion of the portion deteriorates, this is between the heat transfer tubes 2. Other parts that are sandwiched are also linked to cause adverse effects.

Therefore, in the present embodiment, the spot welding or laser welding is performed only on the fin collar center top portion 33 a located on the outermost side of the fin 3.
According to the heat exchanger, the heat exchanger fin, and the heat exchanger manufacturing method according to the third embodiment of the present invention, the welding work time is minimized and good adhesion between the fin 3 and the heat transfer tube 2 is maintained. In addition, the desired heat transfer performance can be obtained.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

100 fin tube type heat exchanger (heat exchanger), 1 minute pipe, 2 heat transfer pipe,
21 arc-shaped R part, 22 plane part, 23 partition, 3 fin, 203 fin,
31 base surface, 32 opening, 33,233 fin collar,
33a, 233a fin collar center top, 33b, 233b fin collar side surface,
233c, 233d Protruding part, 34, 35 Heat sink, 36 slit, 13 welded part.

Claims (11)

A heat transfer tube,
In the heat exchanger having a fin that is attached to the heat transfer tube in a direction perpendicular to the axial direction of the heat transfer tube and exchanges heat between the medium passing through the heat transfer tube and the outside air,
The fin has an opening for mounting on the heat transfer tube,
In the portion surrounding the heat transfer tube at the edge of the opening, it has a fin collar protruding in the axial direction of the heat transfer tube,
The fin collar and the heat transfer tube are temporarily fixed by welding. The heat exchanger according to claim 1, wherein the fin collar has a welding protrusion that protrudes in an axial direction of the heat transfer tube. The heat exchange according to claim 1 or 2, wherein the fin has a plurality of openings for mounting on the heat transfer tube, and the welding is performed only on the fin collars at both ends of the fin. vessel. The heat exchanger according to any one of claims 1 to 3, wherein the welding is performed on at least a central top portion of the fin collar. The heat exchanger according to any one of claims 1 to 4, wherein the welding is spot welding or laser welding. The heat exchanger according to any one of claims 1 to 5, wherein the fin collar and the heat transfer tube are bonded and fixed. In the heat exchanger fin that is attached to the heat transfer tube in a direction perpendicular to the axial direction of the heat transfer tube and exchanges heat between the medium passing through the heat transfer tube and the outside air,
The fin has an opening for mounting on the heat transfer tube, and has a fin collar projecting in the axial direction of the heat transfer tube in a portion surrounding the heat transfer tube of the opening,
The fin collar is a fin for a heat exchanger that further includes a welding protrusion protruding in the axial direction of the heat transfer tube. The heat exchanger fin according to claim 7, wherein the welding protrusion is provided at least at a central top of the fin collar. A heat transfer tube,
In the method of manufacturing a heat exchanger, the heat transfer tube includes a fin that is mounted in a direction perpendicular to the axial direction of the heat transfer tube and that exchanges heat between the medium passing through the heat transfer tube and the outside air.
The fin has an opening for mounting on the heat transfer tube,
The edge of the opening has a fin collar protruding in the axial direction of the heat transfer tube,
A fin mounting step for mounting the fin in the opening so that the fin collar is in close contact with the heat transfer tube;
A welding step of temporarily fixing the fin collar and the heat transfer tube;
A method for manufacturing a heat exchanger, comprising: the fin collar; and a bonding step of bonding and fixing the heat transfer tube. The fin collar has a protruding portion for welding protruding in the axial direction of the heat transfer tube,
The method for manufacturing a heat exchanger according to claim 9, wherein, in the welding process, the welding protrusion and the heat transfer tube are welded. The method for manufacturing a heat exchanger according to claim 9 or 10, wherein spot welding or laser welding is performed in the welding step.

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