JP2008275210A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize a plate thickness of a case and to provide a heat exchanger with sufficient strength. <P>SOLUTION: A side face 4a of the case 4 and a flat tube 1 are integrally joined through projecting portions 5, 6, a plane surface 4b of the case 4 and the flat tube 1 are formed with a little clearance, a plurality of reinforcement ribs 7 are formed on the plane surface 4b, and the reinforcement ribs 7 are integrally brazed and fixed by a reinforcement plate 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger for hot gas cooling.

  Conventional heat exchangers for cooling high-temperature gas mainly use stainless steel, and each part is brazed and fixed with nickel brazing. This nickel brazing is usually made of powder, which is adhered to the joints of the parts via a paste agent, and is brazed and fixed integrally in a furnace or the like in a state where the parts are assembled.

When stainless steel is used as the material for the high temperature gas heat exchanger, brazing is extremely troublesome and the brazing material is expensive, resulting in high costs for the high temperature gas heat exchanger. Therefore, an aluminum material can be used instead of stainless steel. In that case, aluminum clad material or the like is used to reduce the number of manufacturing steps, and brazing can be performed relatively easily, so that cost reduction is expected.
However, aluminum materials have the disadvantage of being inferior in strength compared to stainless steel. Therefore, it is necessary to make the plate thickness sufficiently thick. This leads to an increase in material costs.

In order to improve the strength, it is usual to provide a large number of ribs on the plate material. Then, the material of the rib portion is stretched, and the plate thickness is partially reduced.
Usually, in a pressure test of a heat exchanger, when a predetermined pressure is applied, the deformation amount is set to 0.2% or less. Beyond that, the gap between the case and each flat tube becomes large, and cooling water bypasses from the gap, resulting in a disadvantage that it does not circulate uniformly in each part of the flat tube. Furthermore, stress concentrates on the joint of each component, and durability is reduced.
Therefore, an object of the present invention is to provide a heat exchanger that uses a thin aluminum plate as much as possible, provides ribs and protrusions to enhance strength, and reinforces a weak portion.

The present invention according to claim 1 includes a core (3) in which both ends of a number of parallel flat tubes (1) are penetrated by a header plate (2),
A substantially rectangular case (4) that fits the outer periphery between the header plates (2), and
Each flat tube (1) has a pair of opposed flat portions (1a) parallel to the major axis of its cross section and an arcuate portion (1b) that integrally connects both edges in the width direction of both flat portions. In the flat portion (1a), a large number of convex portions (5) are spaced apart from each other and project integrally on the outer surface side thereof, and the adjacent flat tubes (1) are in contact with the tips of the convex portions (5),
In the case (4), a plurality of convex portions (6) are integrally projected on the side surface (4a) parallel to the flat portion (1a) of each flat tube (1) on the inner surface side thereof. On the plane (4b) orthogonal to 4a), a plurality of reinforcing ribs (7) are separated from each other and extend integrally in the width direction of the case,
The flat tube (1) located on the outermost side of the core (3) has its convex portion (5) in contact with the convex portion (6) of the side surface (4a) of the case (4), and each flat tube (1 ) Between the arcuate part (1b) and the plane (4b) of the cooler case (4) has a gap (t),
The reinforcing plate (8) is in contact with only the flat surface (4b) side of the case (4) so that the plurality of reinforcing ribs (7) are connected,
The heat exchanger is characterized in that each contact portion of each component is integrally brazed and fixed.

The present invention according to claim 2 is the method according to claim 1,
One or more ribs (12) are bent on the reinforcing plate (8), and the rib (12) and the reinforcing rib (7) are joined so as to intersect with each other.

In the heat exchanger of the present invention, the reinforcing plate 8 is in contact with only the flat surface 4b of the case 4 and is integrally brazed and fixed so that the plurality of reinforcing ribs 7 are connected. As a whole, a high-temperature gas heat exchanger with high pressure resistance can be provided.
That is, the side surface 4a of the case 4 is a portion having a large pressure resistance because a large number of convex portions 6 projecting from the side surface 4a are in contact with the large number of convex portions 5 of the flat tube 1 and are integrally brazed and fixed. Only the flat surface 4b of the case 4 facing the flat tube 1 with a gap is a portion having a low pressure resistance, but since the flat surface 4b is reinforced by the reinforcing plate 8, the pressure resistance is increased. Thereby, the pressure resistance as a whole can be improved without increasing the thickness of the entire case 4.
In the above configuration, in the case where one or more ribs 12 are bent on the reinforcing plate 8 and the ribs 12 and the reinforcing ribs 7 are joined so as to intersect, the pressure resistance can be further improved.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a schematic perspective view showing a state in which the reinforcing plate 8 is disassembled, FIG. 2 is a cross-sectional view of the main part of the heat exchanger for high-temperature gas, and FIG. It is a longitudinal cross-sectional view.

In this heat exchanger, a large number of flat tubes 1 are arranged in parallel, and both ends (one side is omitted; the same applies hereinafter) of each flat tube 1 are passed through a header plate 2 to form a core 3. The case 4 is fitted on the outer periphery of the core 3, and the opening of the header 11 is joined to the periphery of the header plate 2 or the edge of the case 4.
The flat tube 1 has a pair of flat portions 1a facing each other, and both ends of the flat portion 1a are integrally connected by an arcuate portion 1b. A large number of convex portions 5 are formed at regular intervals on the outer surface side of the flat portion 1a.
Such a flat tube 1 can be formed by forming a pair of plates into shallow grooves by press molding and fitting them in opposite directions. The convex portions 5 of the flat tubes 1 arranged in parallel are in alignment with each other in this example, but may not be aligned.

Next, the case 4 is fitted on the outer periphery of the core 3 made of the aggregate of the flat tubes 1. The cross section of the case 4 is formed in a substantially square shape, and a large number of convex portions 6 project from the inner surface side of the same side surface 4a. In this example, the position of the convex portion 6 is aligned with the convex portion 5 of the flat tube 1, but may not be aligned. In addition, a large number of reinforcing ribs 7 extend in the width direction on the plane 4b that is orthogonal to the side surface 4a.
Then, both end openings of the case 4 are fitted on the outer periphery of the header plate 2. One end of the cooling water pipe 9 communicates with the outer periphery of both ends in the longitudinal direction of the case 4. The upper and lower ends of the flat tube 1 are not in contact with the case 4 and a gap t is formed.
By providing the gap t in this way, the cooling water supplied from the cooling water pipe 9 can be evenly distributed to the outer periphery of each flat tube 1.

Next, in this example, a flat reinforcing plate 8 is arranged so as to connect the reinforcing ribs 7 of the case 4, and in the assembled state, the assembly is inserted into a high-temperature furnace, and integrally It is for brazing and fixing. At this time, one surface of the parts that are in contact with each other is previously coated with a brazing material or a brazing material.
In the high-temperature gas heat exchanger thus configured, the high-temperature gas 14 is guided from one header 11 into each flat tube 1 and flows out from the other header 11. Then, the cooling water 13 flows into the case 4 from the cooling water pipe 9 provided at one end in the longitudinal direction of the case 4, flows through the outer periphery of each flat tube 1, and flows out from the other cooling water pipe 9. Then, heat exchange is performed between the cooling water 13 and the high-temperature gas 14.

  Next, FIG. 4 shows a second embodiment of the present invention. The only difference from FIG. 1 is the shape of the reinforcing plate 8. In this example, a plurality of ribs 12 extend integrally in the longitudinal direction on the surface of the reinforcing plate 8, and the ribs 12 and the reinforcing ribs 7 of the case 4 are joined so as to intersect. By providing the rib 12 on the reinforcing plate 8 in this way, the strength of the case 4 on the flat surface 4b side can be further improved.

It is a principal part perspective view of the heat exchanger of this invention, Comprising: The reinforcement board 8 is decomposed | disassembled and a state is shown. The principal part cross-sectional view of the heat exchanger for the high-temperature gas. The principal part longitudinal cross-sectional view. It is a principal part perspective view which shows the other example of the heat exchanger of this invention, Comprising: The reinforcement board 8 is decomposed | disassembled and a state is shown.

Explanation of symbols

1 Flat tube
1a Flat part
1b Arc
2 Header plate
3 core
4 cases
4a side
4b plane
5 Convex

6 Convex
7 Reinforcing ribs
8 Reinforcement plate
9 Cooling water pipe
10 Notch
11 Header
12 ribs
13 Cooling water
14 Hot gas

Claims (2)

A core (3) in which both ends of a number of parallel flat tubes (1) are penetrated by a header plate (2);
A substantially rectangular case (4) that fits the outer periphery between the header plates (2), and
Each flat tube (1) has a pair of opposed flat portions (1a) parallel to the major axis of its cross section and an arcuate portion (1b) that integrally connects both edges in the width direction of both flat portions. In the flat portion (1a), a large number of convex portions (5) are spaced apart from each other and project integrally on the outer surface side thereof, and the adjacent flat tubes (1) are in contact with the tips of the convex portions (5),
In the case (4), a plurality of convex portions (6) are integrally projected on the side surface (4a) parallel to the flat portion (1a) of each flat tube (1) on the inner surface side thereof. On the plane (4b) orthogonal to 4a), a plurality of reinforcing ribs (7) are separated from each other and extend integrally in the width direction of the case,
The flat tube (1) located on the outermost side of the core (3) has its convex portion (5) in contact with the convex portion (6) of the side surface (4a) of the case (4), and each flat tube (1 ) Between the arcuate part (1b) and the plane (4b) of the cooler case (4) has a gap (t),
A reinforcing plate (8) is in contact with only the flat surface (4b) side of the case (4) so that a plurality of the reinforcing ribs (7) are connected,
A heat exchanger characterized in that each contact portion of each component is integrally brazed and fixed. In claim 1,
One or more ribs (12) are bent on the reinforcing plate (8), and the rib (12) and the reinforcing rib (7) are joined so as to intersect.

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