JP2001174169A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat exchanging efficiency (cooling capacity) of an EGR gas cooler. SOLUTION: There is provided a guide seal wall 113 for preventing the flow of EGR gas, flowing into a core casing 143 (an exhaust passage 110) while detouring a gap 112 between tubes 110 with a high flow resistance. According to this method, much of the EGR gas, which has flowed into the core casing 143, can be prevented from flowing through a site (a gap 144 between cores) having no inner fins 111 and reduced in a heat exchanging efficiency. Accordingly, much of the EGR gas can be conducted to flow through the gap 112 between the tubes 110 having a high heat exchanging efficiency whereby the heat exchanging efficiency (the cooling performance) can be improved and the EGR gas can be cooled sufficiently.

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 is effective when applied to an exhaust heat exchanger for exchanging heat between exhaust gas discharged from an internal combustion engine and a coolant.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view of an EGR gas cooler (a heat exchanger for cooling exhaust gas for an EGR (exhaust gas recirculation device)) which is under study by the inventors and the like. The heat exchanger includes a heat exchange core 130 that exchanges heat with the cooling water, and a box-shaped core casing 143 that accommodates the heat exchange core.

The heat exchange core 130 includes a flat tube 120 through which cooling water flows, and fins 111 disposed in a gap 112 between the tubes 120. Further, the exhaust gas flows around the heat exchange core 130 (in the core casing 143), exchanges heat with cooling water flowing in the tube 120, and is cooled.

[0004]

In the above-mentioned prototype, the fins 111 are provided in the gaps between the tubes 120 in order to promote heat exchange between the cooling water and the exhaust gas. The gap 1 between the tubes 120
Since the flow resistance of the exhaust gas at 12 increases, the exhaust gas flowing through the core casing 143 flows through a portion (portion A in FIG. 9) where the fin 111 having a low flow resistance does not exist.

[0005] For this reason, in the above-mentioned prototype, most of the exhaust gas flows through a portion A where there is no fin having a low heat exchange efficiency (a portion in the core casing where the heat exchange core does not exist). It has a problem that it is difficult to sufficiently cool it.

The present invention has been made in view of the above circumstances, and has as its object to improve heat exchange efficiency.

[0007]

According to the present invention, in order to achieve the above object, in the invention according to claim 1, a plurality of tubes (120) through which a first fluid flows, and a space between the tubes (120) are provided. Heat exchange core (13) having fins (111) disposed in the gap (112) for promoting heat exchange between the first fluid and the second fluid flowing outside the tube (120).
0) and a core casing (143) that houses the heat exchange core (130) and forms a fluid passage (110) through which the second fluid flows.
In 3), a fluid guide (113) for preventing the second fluid from flowing around the gap (112) between the tubes (120) is provided.

Thus, most of the second fluid flowing into the core casing (143) can be passed through the gap (112) between the tubes (120) provided with the fins (111), so that heat exchange is performed. The heat exchange efficiency (cooling capacity) of the vessel can be improved.

According to the second aspect of the present invention, the plate members (131, 132) press-formed into a predetermined shape are
A tube (120) is formed by laminating the plate members (131, 132) in the thickness direction, and a gap (14) is formed at an end (121) in the width direction of the tube (120).
4), and a gap (144) formed between the width direction end (121) of the tube (120) and the inner wall of the core casing (143) is provided over the entire area of the plate members (131, 132) in the stacking direction. In a state where the fluid guide portion (113) is in communication with the end portion (12) of the tube (120),
It may be formed between 1) and the inner wall of the core casing (143).

[0010] Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
The heat exchanger according to the present invention is applied to an EGR gas cooling device for a diesel engine (internal combustion engine), and FIG. 1 uses an EGR gas cooling device (hereinafter, referred to as a gas cooler) 100 according to the present embodiment. FIG. 2 is a schematic diagram of an EGR (exhaust gas recirculation device) that has been used.

In FIG. 1, reference numeral 200 denotes a diesel engine (hereinafter abbreviated as engine), and reference numeral 210 denotes an engine 20.
This is an exhaust recirculation pipe that recirculates part of the exhaust gas discharged from the exhaust pipe to the intake side of the engine 200.

A reference numeral 220 is provided in the exhaust gas recirculation pipe 210 in the middle of the exhaust gas flow.
The gas cooler 100 is a well-known EGR valve that adjusts the amount of GR gas. The gas cooler 100 is disposed between the exhaust side of the engine 200 and the EGR valve 220, and includes EGR gas and engine cooling water (hereinafter, abbreviated as cooling water). Heat exchange between EG
Cool the R gas.

Next, the structure of the gas cooler 100 will be described.

FIG. 2 is an external view of the gas cooler 100.
3 is a sectional view taken along line AA of FIG. 2, and FIG. 4 is a sectional view taken along line BB of FIG.
FIG. 5 is a cross-sectional view of FIG. 2 taken along the line CC. 3 to 5, reference numeral 110 denotes an exhaust passage through which EGR gas (second fluid) flows, and reference numeral 120 denotes a tube through which cooling water (first fluid) flows.

The tube 1 in the exhaust passage 110
For example, as shown in FIG.
Inner fins 11 made of stainless steel for increasing the contact area with the GR gas to promote heat exchange between the EGR gas and the cooling water
The inner fin 111 has portions shifted from each other in a direction orthogonal to the EGR gas flow in order to suppress the growth of the temperature boundary layer of the EGR gas in the exhaust passage 110. It is an offset fin.

The offset fins (multi-entry fins) are described in the heat exchanger design handbook (published by Kogyo Tosho Co., Ltd.) and the 19th Japan Heat Transfer Symposium, etc. , Plate-shaped segments are offset and arranged in a staggered manner.

The tube 120 is formed by laminating laminated plates (plate materials) 131 and 132 which are press-formed into a predetermined shape.
The EGR gas and the cooling water are formed by stacking the stacking plates 131 and 132 and the inner fins 111 alternately by stacking the stacking plates 131 and 132 and the inner fins 111 as a set. A heat exchange core 130 for exchanging heat is configured.

Reference numeral 140 denotes a box-shaped core tank for storing the heat exchange core 130, and 141 denotes a core tank
Heat exchange core 130 (laminated plate 13)
1, 132) are core caps (core plates) for closing the openings 142 for incorporating the core caps 1 and 132).
41 is joined to the core tank 140 in a state of being fitted (inserted) so as to be in contact with the inner wall of the core tank 140. Hereinafter, the core tank 140 and the core cap 1
The container composed of 41 is called a core casing 143.

Therefore, the space inside the core casing 143 around the heat exchange core 130 constitutes the exhaust passage 110. In the present embodiment, as shown in FIG. 5, the end 121 of the tube 120 in the width direction (paper width direction) orthogonal to the longitudinal direction (perpendicular to the paper surface) is
It is separated from the inner wall of the core casing 143 by a predetermined gap 144 (hereinafter, this gap is referred to as an inter-core gap).

The EG that has flowed into the core casing 143 (exhaust passage 110) enters the inter-core gap 144.
The R gas flows into the gap 1 between the tubes 110 having large flow resistance.
A guide seal wall (fluid guide portion) 113 is provided to prevent the EGR gas from flowing into the inter-core space 144 having a small flow resistance and bypass the EGR gas into the gap 112 between the tubes 110. I have.

Here, the width direction end 12 of the tube 120 is
1 does not include the overlapping margin portion 121a of the two laminated plates 131 and 132, and substantially coincides with the width direction end on the inner wall side.

As shown in FIG. 6, the guide seal portion 113 is a part of the extension portion 111a that extends from the widthwise end 121 of the tube 120 toward the inner wall of the core casing 143 on the inner fin 111. Is bent to obstruct the flow of the EGR gas flowing through the inter-core gap 144 (EG
A wall surface where the R gas flows intersect is formed).

Further, the inter-core gap 1 is provided in the extension portion 111a.
A communication hole 111b is formed to allow the EG 44 to communicate over the entire area of the stacking plates 131 and 132 in the stacking direction.
The condensed water generated in the R gas flows down the core casing 143 through the communication hole 111b. Therefore, in the present embodiment, anticorrosion treatment such as plating is performed on the inner wall of the core casing 143.

In this embodiment, the laminated plate 1
31, 132, core tank 140 and core cap 14
1 is made of stainless steel having excellent corrosion resistance.
1, 132, 140, 141 are brazed using, for example, copper or a nickel alloy as a brazing material.

2 to 4, reference numeral 151 denotes a cooling water introduction pipe for guiding the cooling water to the heat exchange core 130.
Reference numeral 52 denotes a cooling water discharge pipe for discharging the cooling water after the heat exchange. In addition, reference numeral 153 indicates that the exhaust is
(Exhaust passage 110) is an exhaust introduction joint part, and 154 is an exhaust discharge joint part that exhausts the exhaust gas after the heat exchange.

Next, an outline of a method of manufacturing the gas cooler 100 will be described.

As shown in FIGS.
The heat exchange cores 130 are temporarily assembled on the core cap 141 by sequentially laminating the laminated plates 131 and 132 and the inner fins 111 on the core cap 141 (core assembling step).

Next, the core tank 140 is covered so as to cover the heat exchange core 130 from above the heat exchange core 130, and the core tank 140 is compressed from above with a jig to compress the core cap 141, the heat exchange core 130, Temporary fixing step of temporarily fixing the core tank 140).

Then, the laminate plate 13 is heated in a furnace.
1, 132, the inner fin 111 core tank 140 and the core cap 141 are integrally brazed (brazing step).

Next, the features of this embodiment will be described.

According to the present embodiment, the core casing 14
Since the guide seal wall 113 is provided to prevent the EGR gas flowing into 3 (exhaust passage 110) from flowing around the gap 112 between the tubes 110 having a large flow resistance due to the presence of the fin, Core casing 143
Most of the EGR gas that has flowed into the space has a portion where the inner fin 111 with low heat exchange efficiency does not exist (the gap 14 between the cores).
4) can be prevented from being distributed.

Therefore, the tube 1 having high heat exchange efficiency
Since a large amount of EGR gas can be passed through the gap 112 between the gas coolers 100, the heat exchange efficiency (cooling capacity) of the gas cooler 100 can be improved, and the EGR gas can be sufficiently cooled.

(Second Embodiment) In the first embodiment, the guide seal portion 113 is formed by bending a part of the extension portion 111a of the inner fin 111. In this embodiment, as shown in FIG. , A part of the segment 111c of the inner fin 111 is bent to form a guide seal portion 113.
Is formed.

(Third Embodiment) In the above embodiment, the guide seal portion 113 is formed integrally with the inner fin 111. However, in this embodiment, the guide seal portion 113 is formed as shown in FIG. And is joined to the inner wall of the core casing 143.

(Other Embodiments) In the above embodiments, offset type fins are used. However, the present invention is not limited to this, and other types of fins such as pin-shaped fins may be used. Good.

In the above embodiment, the tube 120 is formed by laminating the laminated plates (plate materials) 131 and 132. However, the present invention is not limited to this. Other tubes, such as integrally formed, may be used.

The shape of the tube 120 is not limited to a flat shape, but may be any other shape such as a circle or a polygon.

In the above embodiment, the gas cooler 1
Although the exhaust heat exchange apparatus according to the present invention is applied to 00, it may be applied to other heat exchangers such as a heat exchanger that is disposed in a muffler and recovers heat energy of exhaust gas.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an EGR gas cooling device using a heat exchanger (gas cooler) according to a first embodiment of the present invention.

FIG. 2 is a gas cooler 100 according to the first embodiment of the present invention.
FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

FIG. 5 is a sectional view taken along the line CC of FIG. 2;

FIG. 6 is a perspective view of a fin according to the first embodiment of the present invention.

FIG. 7 is a perspective view of a fin according to a second embodiment of the present invention.

FIG. 8 is a front view of a guide seal portion according to a third embodiment of the present invention.

FIG. 9 is a sectional view of a prototype gas cooler.

[Explanation of symbols]

110 ... exhaust passage, 111 ... inner fin, 113 ...
Guide seal portion, 120: tube, 130: heat exchange core, 143: core casing.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsunori Uchimura 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Kazuhiro Shibaki 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation F term (reference) 3L065 BA04 EA05 3L103 AA37 BB17 BB39 CC02 CC26 DD12 DD18 DD32 DD53 DD56 DD63 DD68 DD97

Claims (3)

[Claims] A plurality of tubes (120) through which a first fluid flows, and a gap (1) between the tubes (120).
12) and the first fluid and the tube (12).
0) a heat exchange core (130) having fins (111) for promoting heat exchange with a second fluid flowing outside, and a fluid containing the heat exchange core (130) and through which the second fluid flows And a core casing (143) constituting a passage (110). In the core casing (143), the second fluid flows around the gap (112) between the tubes (120). A heat exchanger, characterized by being provided with a fluid guide (113) for prevention. 2. The tube (120) is formed by laminating plate members (131, 132) pressed in a predetermined shape in the thickness direction of the plate members (131, 132). Of the core casing (1), the end (121) in the width direction orthogonal to the longitudinal direction is provided.
43) is spaced apart from the inner wall of the tube (120) with a predetermined gap (144), and is formed between the width-direction end (121) of the tube (120) and the inner wall of the core casing (143). (144) The plate material (131, 132)
And the fluid guide portion (113) is provided between the width direction end (121) of the tube (120) and the inner wall of the core casing (143). 2. The device according to claim 1, wherein the gap is formed in the gap.
A heat exchanger according to item 1. 3. The heat exchanger according to claim 1 or 2, wherein the heat exchanger according to claim 1 is applied to an exhaust heat exchanger for exchanging heat between an exhaust gas of an internal combustion engine and a coolant. A heat exchanger characterized by flowing a liquid and flowing the exhaust gas through the fluid passage (110).