JPH0979766A - Heat exchanger and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heat exchange performance by integrating plate-shaped fins and flat heat exchange pipes into a unit body by brazing. SOLUTION: On a surface of a flat heat exchanger pipe 3 made of an extruded aluminum alloy shape, an aluminum alloy layer 10 having a melting point lower than either of those of the flat heat exchanger pipe 3 and a plate-shaped fin 1 made of an aluminum alloy material is formed to braze the heat exchanger pipe 3 and the plate-shaped fin 1 to one another.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger and a method for manufacturing the same, and more specifically, it is used as a heat exchanger for air conditioners and refrigeration equipment, and is used for heat pumps such as condensers and evaporators. The present invention relates to an aluminum alloy heat exchanger applicable to any of the above and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, an aluminum heat exchanger in which an aluminum alloy (hereinafter referred to as aluminum) fin and an aluminum heat exchange tube are brazed is widely used. As this type of heat exchanger, as shown in FIG. 6 and FIG. 7, plate-shaped fins a which are arranged at appropriate intervals are penetrated by a round tube-shaped heat exchange tube b,
A heat exchanger formed by expanding the heat exchange tube b and closely contacting with the plate-shaped fin a. As shown in FIGS. 8 and 9, a flat heat exchange tube c formed by an aluminum extruded shape has a long side. A heat exchanger is known in which a plurality of stages are arranged in parallel with each other and corrugated fins d are arranged in the gaps. When manufacturing such a heat exchanger, a flat heat exchange tube c and a corrugated fin d are brazed and integrated by using a brazing sheet for the corrugated fin d.

[0003]

However, in the above heat exchanger, since the heat exchange tube b is a round tube,
The heat exchange tube b was a cause of increased ventilation resistance. Therefore, there is a problem that the pitch of the heat exchange tubes has to be made coarse, the fin efficiency becomes low, and the heat exchange performance cannot be improved.

On the other hand, in the above heat exchanger, since the heat exchange tubes are flat, the influence on the ventilation resistance of the heat exchange tubes can be reduced, and therefore the pitch of the heat exchange tubes can be reduced. Therefore, the heat exchange performance can be improved. However, since the corrugated fins d are used, there is a problem that dew condensation water when used as an evaporator and drainage during defrosting operation of frost are poor, which adversely affects performance.

As a means for solving the above problem, it is conceivable to arrange a plurality of flat heat exchange tubes through a plurality of plate fins arranged at appropriate intervals so as to penetrate the flat heat exchange tubes. In this structure, it is difficult to connect the fin and the flat heat exchange tube. That is, since the heat exchange tube is flat, the flat heat exchange tube c is formed of an extruded shape member having a reinforcing wall in order to have pressure resistance.
It is difficult to bring the flat heat exchange tube having such a reinforcing wall into close contact with the fin by expanding the tube.

In the above heat exchanger, it is possible to braze the fins and the heat exchange tubes by using a brazing sheet for the corrugated fins.
When a brazing sheet is used for the plate-shaped fins a, the plate-shaped fins a are fused to each other, which makes it difficult to braze the plate-shaped fins a with the flat heat exchange tubes c. In this case, when the flat heat exchange tube c is an electric resistance welded tube using a brazing sheet and the plate fin a is a material, brazing is possible, but in order to have pressure resistance of the heat exchanger. However, since it is necessary to separately braze a member corresponding to the reinforcing wall inside the electric resistance welded pipe, there is a problem that the manufacturing process becomes complicated.

The present invention has been made in view of the above circumstances. The pitch of the heat exchange tubes can be reduced to improve the fin efficiency, the heat exchange performance can be improved, and dew condensation when used as an evaporator can be achieved. An object of the present invention is to provide a heat exchanger capable of favorably draining water and frost during defrosting operation, and a method of manufacturing the heat exchanger, which facilitates the production thereof.

[0008]

In order to achieve the above object, the heat exchanger of the present invention comprises a plurality of plate fins arranged at appropriate intervals and parallel to each other penetrating the plate fins. A plurality of flat heat exchange tubes and a pair of headers arranged at a distance from each other and communicating with the flat heat exchange tubes are integrally brazed (claim 1).

In the heat exchanger of the present invention, it is preferable to provide a rising piece that comes into contact with the surface of the flat heat exchange tube at the edge of the flat heat exchange tube insertion hole provided in the plate fin. ). Further, it is possible to provide an abutting piece that abuts an adjacent plate-shaped fin on the top of the standing piece (claim 3). Further, it is preferable that the plate fins are made of an aluminum alloy member and the flat heat exchange tubes and the header are made of an aluminum alloy extruded shape member (claim 4).

The heat exchanger manufacturing method of the present invention is
In manufacturing the heat exchanger according to claim 4, an aluminum alloy layer having a melting point lower than those of the flat heat exchange tube and the plate fins is formed on the surface of the flat heat exchange tube, and the flat heat exchange tube is formed. The tube and the plate fin are brazed (claim 5).

In the method of manufacturing the heat exchanger, in order to form the aluminum alloy layer, for example, Al--Si,
A mixture of a brazing filler metal powder of Al-Cu or Al-Si-Cu, a flux powder, and a binder is applied to the surface of a flat heat exchange tube made of aluminum or an aluminum alloy, and heated to a temperature higher than the brazing filler metal melting temperature, A brazing material alloy layer can be formed on the surface of the flat heat exchange tube.

Another method for forming an aluminum alloy layer is to mix copper or silicon, which has a lower melting point than a flat heat exchange tube made of aluminum or aluminum alloy, or both, a flux powder, and a binder. Then, while applying to the surface of the flat heat exchange tube, it is heated above the eutectic point to form a brazing alloy layer on the surface of the flat heat exchange tube by alloying the mixture with the surface of the base material. Good.

Further, as another method for forming an aluminum alloy layer, copper or silicon or both of which the eutectic point with aluminum has a lower melting point than that of a flat heat exchange tube made of aluminum or aluminum alloy, and aluminum powder When,
Flux powder and a binder are mixed and applied to the surface of the flat heat exchange tube, and heated to a temperature higher than the eutectic point, and the mixture of alloys is alloyed to form the base material wax on the surface of the flat heat exchange tube. A material alloy layer may be formed.

As another method for forming an aluminum alloy layer, Al-Si, Al-Cu or Al-Si is used.
-A Cu alloy is sprayed onto the surface of a flat heat exchange tube made of aluminum or an aluminum alloy, and a flux is applied to the surface of the flat heat exchange tube to heat it to a temperature above the melting temperature of the alloy to form a brazing alloy layer on the surface of the flat heat exchange tube. May be formed.

As another method for forming an aluminum alloy layer, powder of copper or silicon or both of which has a lower eutectic point with aluminum than the flat heat exchange tube made of aluminum or aluminum alloy, While spraying on the surface of the flat heat exchange tube, apply a flux and heat it to a temperature above the eutectic point to form a brazing alloy layer on the surface of the flat heat exchange tube by alloying the mixture with the base material. You may let me.

As another method for forming an aluminum alloy layer, powder of copper or silicon or both of which has a lower eutectic point with aluminum than the flat heat exchange tube made of aluminum or aluminum alloy, and While spraying aluminum powder and the flat heat exchange tube surface, apply flux and heat to above the eutectic point to form a brazing alloy layer on the flat heat exchange tube surface by alloying the mixture. You may let me.

The above flux is a fluoride type flux,
Although any chloride-based flux or the like may be used, a non-corrosive fluoride-based flux is preferred. Examples of the fluoride-based flux include aluminum fluoride, alkali metal fluorides, alkaline earth metal fluorides, and complex fluorides thereof (for example, KAl ₄ , K ₂ AlF ₅ · H ₂ O, K).
₃ AlF ₆ , AlF ₃ , LiF, CaF ₂ , NaF, Li ₃
AlF ₆ , RbF, CsF, BaF ₂ , AlF ₃ BaF
₂ etc.) or those containing these as the main components are considered.

[0018]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing an example of the heat exchanger of the present invention, and FIG. 2 is a sectional perspective view showing the main part thereof.

The heat exchanger has a plurality of plate-like fins 1 arranged at appropriate intervals, and a plurality of parallel fins penetrating through the plate-like fins 1 and through holes 2 having an approximately flat elliptical shape. The flat heat exchange tube 3 and a pair of headers 4 and 5 arranged at a distance from each other and communicating with the flat heat exchange tube 3.
And are brazed together. In this case, the flat heat exchange tube 3 has a plurality of passages 7 defined by a plurality of reinforcing walls 6. The header 4 is provided with an inlet 8 for the heat medium R, and the other header 5 is provided with an outlet 9 (see FIG. 2).

In the heat exchanger configured as described above, the headers 4 and 5 and the flat heat exchange tubes 3 are formed of aluminum alloy extruded shape members, and the plate fins 1 are formed of aluminum alloy plate materials. The headers 4, 5, the flat heat exchange tubes 3, and the plate fins 1 are integrally brazed by the manufacturing method of the present invention described later to form a heat exchanger.

In this case, as shown in FIG. 2B, the aluminum alloy layer 10 having a lower melting point than the flat heat exchange tube 3 and the plate fin 1 is formed on the surface of the flat heat exchange tube 3.
Is formed and contributed as a brazing material, the flat heat exchange tube 3 and the plate-shaped fin 1 are integrally brazed. Similarly, the flat heat exchange tube 3 and the headers 4 and 5 are integrally brazed.

In the above embodiment, the case where the edge portion of the substantially flat elliptical insertion hole 2 provided in the plate fin 1 and the surface of the flat heat exchange tube 3 are brazed has been described.
As shown in (a) or (b), a pair of upright pieces 11 are provided in a cut-and-raised manner from the facing long side edges of the flat oval or rectangular insertion holes 2 and 2a to form a flat heat exchange tube surface. The contact area between the flat heat exchange tube 3 and the plate-shaped fin 1 can be increased by bringing the flat heat exchange tube 3 into contact with, and brazing can be performed more firmly. Moreover, the pitch between the plate-shaped fins 1 can be maintained constant by the abutting of the tips of the standing pieces 11 to the adjacent plate-shaped fins 1. Further, as shown in FIG. 3 (c), in addition to the standing pieces 11 cut and raised from the opposite long side edges of the rectangular insertion hole 2, also from the opposite short side edges of the insertion hole 2. By cutting and raising the pair of upright pieces 11a,
Standing pieces 11, 1 on the long side and the short side of the flat heat exchange tube 3.
The flat heat exchange tubes 3 and the plate-shaped fins 1 can be brazed more reliably because the 1a are in contact with each other.

Further, the standing piece 1 constructed as described above.
By providing the abutting pieces 12 that abut the adjacent plate-shaped fins 1 on the tops of the plate-shaped fins 1 and 11a, the pitch between the plate-shaped fins 1 can be reliably maintained (Fig. 4 (a)-
(C) and FIG. 5 (a), (b)). Therefore, brazing between the flat heat exchange tubes 3 and the plate-like fins 1 can be further ensured, and the plate-like fins 1 are arranged at an equal pitch to further ensure the pitch between the plate-like fins 1. be able to.

Next, the manufacturing method of the present invention will be described. First, the flat heat exchange tube 3 is coated or sprayed on the surface of the flat heat exchange tube 3 by a forming method described later to form an aluminum alloy layer 10 having a lower melting point than that of the flat heat exchange tube 3 and the plate-shaped fin 1. A plurality of plate-shaped fins 1 having the exchange tube insertion holes 2 are prepared. Next, the flat heat exchange tube 3 is penetrated through the insertion holes 2 of the plate-shaped fins 1 laminated at appropriate intervals to be laminated, and the flat heat exchange tube 3 and the headers 4 and 5 are communicated with each other. Assemble. Then, the flat heat exchange tubes 3 and the plate-like fins 1 are brazed by heating the brazing filler metal above the melting temperature, and the flat heat exchange tubes 3 and the headers 4 and 5 are brazed.

In this case, Al--Si, Al--Cu or A
A brazing material composed of a 1-Cu-Si brazing material powder and a flux powder is applied to the surface of the flat heat exchange tube 3 and heated to a temperature higher than the melting temperature of the brazing material to form an aluminum alloy on the surface of the extruded flat tube. Layer 10 is formed to form a flat heat exchange tube 3
The plate-shaped fin 1 can be brazed.

As another brazing method, copper (Cu) or silicon (Si), which has a lower eutectic point with aluminum than the base materials of the flat heat exchange tube 3 and the plate-shaped fin 1, and aluminum, and aluminum. Powder is mixed with, for example, a fluoride-based flux powder in which KAlF ₄ and K ₃ AlF ₆ are mixed, and the mixture is applied to the surface of the flat heat exchange tube 3 and heated to a temperature equal to or higher than the eutectic point. The aluminum alloy layer 10 can be formed on the surface of the flat heat exchange tube 3 with a material to braze the flat heat exchange tube 3 and the plate fin 1.

As another brazing method, Al--S
An i, Al-Cu or Al-Cu-Si alloy is sprayed on the surface of the flat heat exchange tube, and a fluoride flux is applied and heated to a temperature above the melting temperature of the alloy to produce a flat heat exchange tube. By forming the aluminum alloy layer 10 on the surface, the flat heat exchange tube 3 and the plate fin 1 can be brazed.

As another brazing method, a powder of Cu or Si and aluminum whose eutectic point with aluminum has a melting point lower than that of the base material of the flat heat exchange tube 3, for example, is used. While being sprayed on the surface, a fluoride-based flux is applied and heated to a temperature above the eutectic point to form an aluminum alloy layer 10 on the surface of the flat heat exchange tube, the flat heat exchange tube 3 and the plate fin. 1 and can be brazed.

As described above, by brazing the flat heat exchange tube 3 and the plate-shaped fin 1 or brazing the headers 4, 5 and the flat heat-exchange tube 3, the plate-shaped fin 1 and the flat fin 1 are flattened. The heat exchanger tube 3 and the headers 4 and 5 can be integrated by brazing. Therefore, the pitch between the plate-shaped fins 1 can be reduced, and the air flow resistance can be reduced by using the flat heat exchange tube 3, so that the heat exchange performance can be improved. . Furthermore,
Since the flat heat exchange pipe 3 is divided into the plurality of passages 7 by the reinforcing wall 6, the pressure resistance can be improved.

[0030]

EXAMPLE Next, an example of a brazing method of the flat heat exchange tube 3 and the plate fin 1 in the present invention will be described. Sample material Flat heat exchange tube: JIS A1050 material 18.8 mm width x 1.9 mm thickness (wall thickness 0.4 mm) Fin material: JIS A3003 + 1.5% Zn material 30.0 mm width x 0.1 mm thickness * Example 1-Al-7.5% Si-1.5% Cu powder-Fluoride-based flux-Binder (thermoplastic acrylic copolymer) mixture applied on the surface of flat heat exchange tube 3 Melting brazing material in nitrogen atmosphere Temperature (eg 600-620
(° C.) or higher to form the aluminum alloy layer 10 on the surface of the flat heat exchange tube 3 and braze it to the plate fin 1.

Example 2 A mixture of Si powder, fluoride flux, and binder (thermoplastic acrylic copolymer) was applied on the surface of the flat heat exchange tube 3 above the eutectic temperature (for example, 590 to 610) in a nitrogen atmosphere.
(.Degree. C.) to form molten metal on the surface of the flat heat exchange tube 3 by the powder and the base material of the flat heat exchange tube 3 and contribute as a brazing material to braze the plate fin 1 .

[Example 3] Arc spraying of Al-12% Si on the surface of the flat heat exchange tube 3 Fluoride flux was applied to the surface of the flat heat exchange tube 3 and the brazing filler metal melting temperature ( For example, 590-6
It heated above (00 degreeC) and brazed with the plate-shaped fin 1.

Example 4 Si powder Cu powder Plasma spraying the above powder mixture on the surface of the flat heat exchange tube 3 Fluoride flux was applied to the surface of the flat heat exchange tube 3 and eutectic in a nitrogen atmosphere. Above temperature (eg 590-61
It was heated to 0 ° C.) to form a molten metal on the surface of the flat heat exchange tube 3 by the powder and the base material of the flat heat exchange tube 3 and contribute as a brazing material to braze the fin.

[0034]

As described above, according to the heat exchanger of the present invention, since the flat heat exchange tube can be used as the heat exchange tube, the ventilation resistance can be reduced,
Moreover, since the interval between the heat exchange tubes can be narrowed, the heat exchange performance can be improved. Moreover, since a plurality of passages can be formed in the flat heat exchange tube by the reinforcing wall, the pressure resistance can be improved. Further, by using the plate-shaped fins, it is possible to improve the drainage of dew condensation water and frost when defrosting.

Further, according to the heat exchanger manufacturing method of the present invention, an aluminum alloy layer having a lower melting point than the flat heat exchange tube and the plate fin is formed on the surface of the flat heat exchange tube, Since the flat heat exchange tube and the plate-shaped fin are brazed, the plate fin and the flat heat-exchange tube can be brazed reliably and firmly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a heat exchanger of the present invention.

FIG. 2 is a sectional view (a) of a main part and an enlarged sectional view (b) of the main part of the heat exchanger of FIG.

FIG. 3 is a perspective view showing another form of the plate-shaped fin according to the present invention.

FIG. 4 is a perspective view showing still another form of the plate fin in the present invention.

5A is a cross-sectional perspective view of a main part of a heat exchanger using the plate-shaped fin shown in FIG. 4A and an enlarged cross-sectional view of the main part in FIG.

FIG. 6 is a perspective view showing a conventional heat exchanger.

7 is an enlarged perspective view of an essential part of the heat exchanger shown in FIG.

FIG. 8 is a perspective view showing another conventional heat exchanger.

9 is a perspective view of a main part of the heat exchanger shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate-shaped fin 2 Insertion hole 3 Flat heat exchange tube 4,5 Header 10 Aluminum alloy layer 11, 11a Standing piece 12 Contact piece

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location F28F 9/02 301 F28F 9/02 301C 9/18 9/18 (72) Inventor Akinori Ogasawara Tokyo 3-13-12 Mita, Minato-ku Japan Light Metal Co., Ltd.

Claims (5)

[Claims] 1. A plurality of plate-shaped fins arranged at appropriate intervals, a plurality of parallel flat heat-exchange tubes penetrating the plate-shaped fins, spaced apart from each other, and having the flat shape. A heat exchanger characterized by integrally brazing a pair of headers communicating with a heat exchange tube. 2. The heat exchanger according to claim 1, wherein an edge portion of the flat heat exchange tube insertion hole provided in the plate-shaped fin,
A heat exchanger comprising a standing piece that comes into contact with the surface of a flat heat exchange tube. 3. The heat exchanger according to claim 1, wherein an edge portion of the flat heat exchange tube insertion hole provided in the plate fin is provided with:
In addition to providing a standing piece that contacts the surface of the flat heat exchange tube,
A heat exchanger characterized in that an abutment piece that abuts an adjacent plate-shaped fin is provided on the top of the standing piece. 4. The plate-shaped fin is formed of an aluminum alloy member, and the flat heat exchange tube and the header are formed of an aluminum alloy extruded shape member. The heat exchanger according to claim 1. 5. In manufacturing the heat exchanger according to claim 4, an aluminum alloy layer having a melting point lower than that of the flat heat exchange tube and the plate fin is formed on the surface of the flat heat exchange tube. A method for manufacturing a heat exchanger, comprising brazing a flat heat exchange tube and a plate fin.