JP2005114251A - Method for manufacturing laminated heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminated heat exchanger, capable of reducing the assembling failure and brazing failure of a tank joint part. <P>SOLUTION: The method for manufacturing a laminated heat exchanger comprises laminating a plurality of tubes 8 each composed of a first tube sheet 6 and second tube sheet 7 having a first tank hole and a second tank hole 13 for carrying in and out a heat exchange medium and an inner fin 6 through outer fins 10, and placing a heat exchanger core 2 composed of the laminated body of the tubes 8 and the outer fins 10 in a vacuum furnace to braze them. When the first tube sheet 6 is laminated on the second tube sheet 7, the opening periphery of the second tank hole 13 of the superposed first tube sheet 6 and second tube sheet 7 is nipped by a tube temporary holding member 14 consisting of a brazing material to temporarily hold the first tube sheet 6 and second tube sheet 7 to be laminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a stacked heat exchanger, for example, and more specifically, manufacturing a stacked heat exchanger formed by brazing a heat exchanger core formed by alternately stacking tube sheets and fins. Regarding the method.

  For example, after applying a water-soluble binder to the surface of the joint between the tube sheet and the fin as one method of forming a laminated heat exchanger in which tube sheets (plates) made of stainless steel and fins are laminated alternately Then, a powdery brazing material made of an alloy containing nickel (Ni) as a main component is applied onto this water-soluble binder, and then heat-treated at 70 ° C. or higher, and then superposed on the joining partner, and then placed in a vacuum furnace. A method of brazing by heating is disclosed (for example, see Patent Document 1).

  FIG. 9 is a perspective view illustrating an example of a heat exchanger core in the stacked heat exchanger, and FIG. 10 is an enlarged cross-sectional view taken along line AA in FIG. As shown in FIG. 9, the heat exchanger core 101 has an inflow tank portion 102 for introducing a heat exchange medium, which is a liquid raw material, into the core, and discharges the heat exchange medium that has flowed into the core to the outside of the core. And an outflow tank unit 103.

  As shown in FIG. 10, the heat exchanger core 101 has a second tube sheet 106 placed on the first tube sheet 104 via an inner fin 105, and further, the second tube sheet 106. A process of placing the first tube sheet 104 over the outer fin 107 via the outer fin 107 is sequentially repeated to form a laminate composed of the tube sheet and the fin, and this laminate is formed by brazing in a vacuum furnace. Has been.

In this heat exchanger core 101, as shown in FIG. 11, powder brazing material 108 is applied to both surfaces of the second tube sheet 106, one surface of the first tube sheet 104, and one surface of the inner fin 105, respectively. Yes. And these 1st tube sheet 104, the inner fin 105, the 2nd tube sheet 106, and the outer fin 107 are joined by heat-melting these powder brazing materials 108. FIG.
JP 2001-150126 A (2nd and 3rd pages, FIG. 1)

  By the way, the tube sheet and the fin are both made of pressed parts having a thin plate thickness, and a brazing material having a large powder size of about 63 μ to 150 μ is used as the powder brazing material.

  For this reason, in the heat exchanger core 101 described above, as shown by a portion surrounded by a dotted line in FIG. 12, a cylinder formed in the first tube sheet 104 and the second tube sheet 106 that form the outflow tank portion 103. It is difficult to align the tank-shaped projections 109 and 110, and one tank-forming projection 109 rides on the other tank-forming projection 110 and easily causes poor assembly. Therefore, in the heat exchanger core 101, if brazing is performed in this state, a brazing failure occurs.

  In addition, since the tube sheet and the fin are formed from the thin plate pressed parts, the heat exchanger core 101 is affected by the warp, and as shown in the portion surrounded by the dotted line in FIG. Is likely to cause separation and cause a brazing failure due to an increase in the clearance of the brazed portion.

  Then, an object of this invention is to provide the manufacturing method of the laminated heat exchanger which can reduce the assembly | attachment defect and brazing defect of a tank matching part.

  In order to achieve the above-described object, the invention according to claim 1 is characterized in that a plurality of tube sheets having tank holes through which the heat exchange medium flows in and out are stacked through fins, and then the tube sheets and fins are stacked. In the method of manufacturing a laminated heat exchanger in which a heat exchanger core made of the laminated body is placed in a vacuum furnace and brazed, when laminating the tube sheets, the peripheral edge of the tank hole opening of the laminated tube sheets It is characterized by being sandwiched by a tube temporary holding member made of a brazing material and temporarily holding these laminated tube sheets.

  Invention of Claim 2 is a manufacturing method of the laminated heat exchanger of Claim 1, Comprising: At the time of the said brazing, the said tube temporary holding member is fuse | melted and used as an auxiliary | assistant brazing material, To do.

  Invention of Claim 3 is a manufacturing method of the laminated heat exchanger of Claim 1 or Claim 2, Comprising: The reinforcing member which clamps the said tube sheets laminated | stacked on the said tube temporary holding member It is characterized by having been buried.

  Invention of Claim 4 is a manufacturing method of the laminated heat exchanger as described in any one of Claims 1-3, Comprising: The opening peripheral part of the said tank hole was made into the flat part. Features.

  According to the first aspect of the present invention, when stacking the tube sheets, the periphery of the tank hole opening of the stacked tube sheets is sandwiched by the tube temporary holding members made of brazing material, and these tube sheets are stacked. Since they are temporarily held together, the tank portion is not misaligned and assembly failure can be prevented. Thereby, according to this invention, the brazing defect can be reduced significantly and the manufacture yield of a laminated heat exchanger can be improved.

  According to the second aspect of the present invention, since the tube temporary holding member is melted during brazing and functions as an auxiliary brazing material, the tube temporary holding member is melted by heating during brazing, and the molten tube temporary holding member is melted. The holding member increases the brazing strength of the tank mating portion as an auxiliary brazing material.

  According to the third aspect of the present invention, since the reinforcing member for sandwiching the tube sheets is embedded in the temporary tube holding member, the holding strength of these tube sheets can be further enhanced by the reinforcing member.

  According to the fourth aspect of the present invention, since the peripheral edge of the opening of the tank hole is a flat portion, the tube temporary holding member can be easily mounted and the passage resistance of the tank portion can be greatly reduced.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

[Configuration of stacked heat exchanger]
First, before describing the method of the present invention, the configuration of the stacked heat exchanger manufactured by the method of the present invention will be briefly described. 1 is a perspective view showing a schematic configuration of a laminated heat exchanger, FIG. 2 is a perspective view of a heat exchanger core in the laminated heat exchanger, FIG. 3 is a perspective view of fins and a tube seat assembly, and FIG. These are the expanded sectional views in the BB line of FIG.

  As shown in FIG. 1, the stacked heat exchanger 1 houses a heat exchanger core 2 that circulates a first heat exchange medium A such as cooling water, and the heat exchanger core 2, and at a high temperature. A case 3 for circulating a second heat exchange medium B such as air, an inlet duct 4 for allowing the second heat exchange medium B to flow into the case 3, and a second heat exchange medium B introduced into the case 3 And an outlet duct 5 for discharging the gas.

  As shown in FIGS. 2 to 4, the heat exchanger core 2 is fixed to the first tube sheet 6 and the first tube sheet 6, and causes the first heat exchange medium A to circulate in the facing portion. In a space portion between the tubes 8 formed of the second tube sheet 7 forming the flow path, the inner fins 9 provided between the first tube sheet 6 and the second tube sheet 7, and the tubes 8 to be laminated. The outer fin 10 is provided, an inflow tank portion 11 for allowing the first heat exchange medium A to flow into the core portion, and a discharge tank portion 12 for discharging the first heat exchange medium A flowing into the core portion. ing.

  As shown in FIGS. 3 and 4, the tube 8 is provided so as to overlap the first tube sheet 6 having a flat plate shape and the first tube sheet 6, and is opposed to the first tube sheet 6. It is formed from a second tube sheet 7 that forms a flow path (void) through which the first heat exchange medium A flows.

  The first tube sheet 6 is formed as a thin plate made of stainless steel and has a first tank hole (not shown) that communicates with the inflow tank portion 11 for introducing the first heat exchange medium A into the heat exchanger core 2. And a second tank hole 13 having a circular shape communicating with the discharge tank portion 12 for discharging the first heat exchange medium A from the heat exchanger core 2 to the outside.

  Similar to the first tube sheet 6, the second tube sheet 7 is formed as a thin plate made of stainless steel, and communicates with the inflow tank portion 11 that introduces the first heat exchange medium A into the heat exchanger core 2. It has a first tank hole (not shown) and a circular second tank hole 13 communicating with the discharge tank part 12 for discharging the first heat exchange medium A from the heat exchanger core 2 to the outside. doing.

  Further, the second tube sheet 7 has a flow path for allowing the first heat exchange medium A to flow into a portion facing the first tube sheet 6 by the other portions excluding the outer peripheral edge bulging upward. (Space part) is formed. In addition, the second tube sheet 7 bulges so that the peripheral portions of the first tank hole and the second tank hole 13 protrude further upward.

  The first tube sheet 6 and the second tube sheet 7 fold the outer peripheral edge portion 6a of the first tube sheet 6 outward and upward and caulk the outer peripheral edge portion 7a of the second tube sheet 7. To form a tube 8 having a flow path through which the first heat exchange medium A flows.

  The inner fin 9 is formed by bending a thin stainless steel plate into a shape that forms a substantially rectangular wave. The inner fin 9 is disposed in a flow path formed as a gap between the first tube sheet 6 and the second tube sheet 7 constituting the tube 8.

  As with the inner fin 9, the outer fin 10 is formed by bending a thin stainless steel plate into a substantially corrugated shape. The outer fin 10 is disposed in a flow path through which the second heat exchange medium B, which is a space formed between the tubes 8 stacked one above the other, flows.

  The heat exchanger core 2 composed of the first tube sheet 6, the second tube sheet 7, the inner fins 9 and the outer fins 10 has a vacuum after applying a powder brazing material to at least the joints. The core components are joined and integrated by brazing in a furnace.

  The heat exchanger core 2 having the above-described configuration constitutes the stacked heat exchanger 1 by being housed in the case 3, and the tube 8 is formed by the first heat exchange medium A flowing inside the heat exchanger core 2. The inner fin 9 and the outer fin 10 are heated or cooled, and when the second heat exchange medium B flows in the vicinity of the heated and cooled tubes 8, the inner fins 9 and the outer fins 10, By reversely cooling or heating the fins 9 and the outer fins 10 to cool or heat the first heat exchange medium A, between the first heat exchange medium A and the second heat exchange medium B. Heat exchange is performed at

[Method of manufacturing heat exchanger core]
Next, a method for manufacturing the heat exchanger core 2 having the above-described configuration will be described. First, the inner fin 9 is disposed on the first tube sheet 6. Next, the second tube sheet 7 is placed on the first tube sheet 6 so as to sandwich the inner fin 9.

  Then, the outer peripheral edge 6 a of the first tube sheet 6 is crimped to the outer peripheral edge 7 a of the second tube sheet 7 by bending the outer peripheral edge 6 a of the first tube sheet 6 inward and downward. Thereby, the tube 8 which consists of the 1st tube sheet 6, the 2nd tube sheet 7, and the inner fin 9 is formed.

  Next, the tube 8 formed as described above is laminated via the outer fin 10. At this time, among the tubes 8 stacked one above the other, the second tank hole 13 formed in the second tube sheet 7 of the lower tube 8 and the first tube sheet 6 of the upper tube 8 respectively. As shown in FIGS. 6 and 7, the peripheral edge of the opening is clamped at several places by a temporary tube holding member 14 as shown in FIG.

  The temporary tube holding member 14 is formed, for example, by casting a nickel (Ni) brazing material into a predetermined shape. In the present embodiment, the temporary tube holding member 14 has a shape in which an egg is cut in half. The tube temporary holding member 14 is formed with a slit 15 for holding the temporarily stacked first tube sheet 6 and second tube sheet 7 to temporarily hold them.

  By attaching the tube temporary holding member 14 to the peripheral edge of the opening of the second tank hole 13, the stacked tubes 8 are temporarily held. Then, the temporary holding action of the tube temporary holding member 14 can reduce the brazing failure of the tank fitting portion.

  By sequentially repeating the above steps, the heat exchanger core 2 formed by stacking a plurality of tubes 8 via the outer fins 10 is formed. In addition, each part before the heat exchanger core assembly includes powder brazing material 108 on both surfaces of the second tube sheet 7, one surface of the first tube sheet 6, and one surface of the inner fin 9, as in FIG. 11. Is applied.

  And this heat exchanger core 2 is put into a vacuum furnace and brazing is performed. Then, the tube temporary holding member 14 functions as an auxiliary brazing material that is melted by heating. That is, when the tube temporary holding member 14 melts, the brazing material spreads over the brazed portions and the surface of the first tube sheet 6 and the second tube sheet 7. As shown in FIG. 4, the tube temporary holding member 14 after melting is thinned, and the opening peripheral portion of the second tank hole 13 of the first tube sheet 6 and the second tube sheet 7 is surely secured. Let braze fix.

  Further, the peripheral edge of the opening of the second tank hole 13 is a flat part, and the tube temporary holding member 14 is melted to reduce its thickness, so that the passage in the second tank hole 13 communicated with the inflow tank part 11. The resistance is greatly reduced, and in particular, the passage resistance of the fluid on the inner fin 9 side can be reduced.

[Effects of the present embodiment]
As described above, according to the manufacturing method of the present embodiment, the first tube sheet 6 and the second tube sheet 7 on which the tubes 8 are laminated are temporarily attached to each other by the tube temporary holding member 14 made of brazing material. Since they are held, there is no misalignment of the inflow tank section 11 and assembly defects can be eliminated.

  Further, according to the manufacturing method of the present embodiment, the tube temporary holding member 14 melts during brazing and acts as an auxiliary brazing material, so that brazing strength can be increased.

  Further, according to the manufacturing method of the present embodiment, in addition to forming the temporary tube holding member 14 with a brazing material, the peripheral edge of the opening of the second tank hole 13 is a flat portion. It is easy to attach the holding member 14 and the passage resistance of the second tank hole 13 can be greatly reduced. Therefore, the heat exchange efficiency of the heat exchanger core 2 can be increased.

[Other embodiments]
Although specific embodiments to which the present invention is applied have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made.

  For example, as shown in FIG. 8, a substantially U-shaped stainless wire 16 which is a reinforcing member for sandwiching the first tube sheet 6 and the second tube sheet 7 of the stacked tubes 8 is used as a temporary tube holding member. 14 may be embedded. By embedding the stainless steel wire 16 in the tube temporary holding member 14, the first tube sheet 6 and the second tube sheet 7 can be temporarily held with a stronger gripping force.

It is a perspective view which shows schematic structure of the laminated heat exchanger of this Embodiment. It is a perspective view of the heat exchanger core in the laminated heat exchanger of this Embodiment. It is a perspective view of the fin and tube assembly which comprise the heat exchanger core in the laminated heat exchanger of this Embodiment. It is an expanded sectional view in the BB line of FIG. It is a perspective view of a tube temporary holding member. It is a principal part expansion perspective view which shows the state which attached the tube temporary holding member to the opening peripheral part of the 2nd tank hole. It is an expanded sectional view which shows the state which attached the tube temporary holding member to the opening peripheral part of the 2nd tank hole of the laminated | stacked tube. (A) is a perspective view of the stainless steel wire which is a reinforcement member, (b) is a perspective view which shows the example which embed | buried the stainless steel wire in the tube temporary holding member. It is a perspective view of the conventional heat exchanger core. It is an expanded sectional view in the AA line of FIG. It is a principal part expanded sectional view which shows the manufacturing process of the conventional heat exchanger core, and shows the state which apply | coated the powder brazing material to the heat exchanger core. It is a principal part expanded sectional view which shows the manufacturing process of the conventional heat exchanger core, and shows the state which one tank formation protrusion got on the other tank formation protrusion, and caused the assembly defect. It is a principal part expanded sectional view which shows the manufacturing process of the conventional heat exchanger core, and shows the state which the brazing defect by the clearance expansion of the brazing part in a tank formation part produced.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated type heat exchanger 2 ... Heat exchanger core 6 ... 1st tube sheet 7 ... 2nd tube sheet 8 ... Tube 9 ... Inner fin 10 ... Outer fin 13 ... 2nd tank hole 14 ... Temporary holding of tube Member 16 ... stainless steel wire (reinforcing member)

Claims (4)

After stacking a plurality of tube sheets having tank holes through which the heat exchange medium flows in and out via fins, a heat exchanger core composed of a laminate of these tube sheets and fins is placed in a vacuum furnace and brazed. In the manufacturing method of the laminated heat exchanger,
When laminating the tube sheets, a tank hole opening peripheral portion of the tube sheets stacked is sandwiched by a tube temporary holding member made of a brazing material, and the tube sheets stacked are temporarily held. A method for manufacturing a laminated heat exchanger. It is a manufacturing method of the lamination type heat exchanger according to claim 1,
In the brazing, the tube temporary holding member is melted and used as an auxiliary brazing material. A method for manufacturing a laminated heat exchanger, wherein: It is a manufacturing method of the lamination type heat exchanger according to claim 1 or 2,
A method of manufacturing a laminated heat exchanger, wherein a reinforcing member for sandwiching the laminated tube sheets is embedded in the temporary tube holding member. It is a manufacturing method of the lamination type heat exchanger according to any one of claims 1 to 3,
The manufacturing method of the laminated heat exchanger, wherein the opening peripheral edge of the tank hole is a flat part.

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