FR2795811A1 - HEAT EXCHANGE DEVICE FOR EXHAUST GAS - Google Patents

Abstract

The device comprises a plurality of units, each consisting of a pair of laminating plates (131, 132), laminated and bonded together by brazing. One of the plates (131) is provided with a first periphery (133) extending in a first stratification direction and the other of the plates (132) is provided with a second projecting periphery (134) extending in the another direction of stratification, these first and second projecting peripheries (133, 134) being able to overlap one another in parallel with directions of stratification of the plates (131, 132) and the overlapping surfaces (133a, 134a) first and second peripheries (133, 134) which can be linked to each other. Thus, the plates (131, 132) can be bonded with sufficient bonding force without forming outwardly folded periphery surfaces perpendicular to the layering directions thereof.

Description

HEAT EXCHANGE DEVICE FOR EXHAUST GAS

Description

  The present invention relates to a heat exchange device for exhaust gas intended for exchanging heat between the exhaust gas of internal combustion engines and a coolant such as water, in particular, applicable to a heat exchange device for cooling an exhaust gas to be used in systems with

  exhaust gas recirculation (EGR).

  EGR systems are used in vehicles to recirculate part of the exhaust gas to a combustion chamber with the aim of lowering the combustion temperature of the fuel so that the formation of nitrogen oxide can be limited. For this purpose, it is preferred that an EGR gas at a lower temperature is

  recirculated to the combustion chamber.

  In a conventional heat exchange device for gases, as indicated in document JP-A-9-310996, exhaust gas passages are composed of a plurality of heat transfer pipes (tubes) whose ends longitudinal opposites are linked to plates

  tubular, respectively, in cylindrical piping.

  However, in order to ensure that a higher heat exchange capacity of the device, it is preferred to use internal fins in the exhaust passages or the

  coolant passages.

  To this end, a heat exchange device for EGR gas of the type with stratification plates comprising internal fins, as indicated in FIG. 22, can be envisaged. According to this device, a plurality of laminating plates, each of which is formed in a given shape by stamping, are laminated so that exhaust gas passages 110 and cooling water passages 120 can be formed

  between two respective adjacent plates among the plates.

  The internal fins are provided in the exhaust gas passages 110 in such a convenient manner that when

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  the laminating plates are laminated one by one, the internal fins can be arranged on the plates

  respective stratification at the level of parts thereof

  ci constituting the exhaust gas passages 110.

  When the thickness of the laminating plate is thinner, the heat exchange capacity of the device can be further increased. Therefore, it is recommended to make the thickness of the laminating plate thinner, as long as the device can endure a pressure applied to it. When the laminating plates are bonded by brazing in such a way that the respective end surfaces of the laminating plates (respective cross-sectional areas of the laminating plates) come into contact with each other, the bonding zones of these are too small to provide sufficient bonding strength. As a result, the respective laminating plates, as indicated in a circle X in FIG. 22, are partly folded outwards in order to constitute peripheral surfaces perpendicular to the directions of lamination of the lamination plates and then, the surfaces outskirts

  are bonded to each other by soldering.

  With the above-mentioned gas heat exchange device, the outer wall surfaces perpendicular to the directions parallel to the plate surfaces of the respective laminating plates must have concave and convex parts, as shown in Figure 22. Although it is preferable that an exhaust inlet 141 and an exhaust outlet 142 are respectively open at the outer wall surfaces perpendicular to the laminating directions of the laminating plates since the exhaust passages and the liquid passages of cooling extend parallel to the plate surfaces of the laminating plates, it is quite difficult to solder the joint assemblies 143, which connect the exhaust gas inlet 141 and the exhaust gas outlet 142 to the pipes exterior, to the exterior wall surfaces perpendicular to the layering directions of s plates

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  stratification due to the existence of the parties

concave and convex.

  Furthermore, in a case where the exhaust gas inlet 141 and the exhaust gas outlet 142 are open at the surface of the outermost plates of the stratification plates parallel to the exhaust gas passages, as shown in FIG. 22, the direction of circulation of the RGE gas is forced to change by an angle of 90 near the inlet 141 and the outlet 142. This poses a problem in that the pressure loss of the EGR gas is important and the flow of EGR gas is reduced. The present invention has been made in view of the problems mentioned above, and an object of the present invention is to provide a heat exchange device for exhaust gases having a heat exchange capacity.

higher heat.

  In order to achieve the above object, the device consists of a plurality of units, each of which consists of a pair of laminating plates (131, 132), laminated and bonded by brazing to each other. the other, exhaust gas passages (110) and coolant passages (120) arranged between two respective plates among the stratification plates (131, 132), internal fins (111) arranged at at least one of the exhaust gas passages (110) and the coolant passages (120), an inlet (141) and an outlet (142) of exhaust gases arranged on opposite sides of the exhaust gas passages (110) and a pair of seal assemblies (143) connected to the laminating plates (131, 132) at the inlet (141) and the outlet ( 142) of exhaust gases intended to connect the external pipes (210) to the exhaust gas passages (110) so as to circulate the g exhaust az perpendicular to the layering directions of the layering plates (131, 132) from one of a pair of seal assemblies (143) through the exhaust gas inlet (141), the passages exhaust gas (110) and the exhaust gas outlet (142)

  toward the other of the pair of seal assemblies (143).

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  With the above-mentioned device, one of the pair of laminating plates (131) of any of the units is integrally provided with a first projecting periphery (133) extending in a laminating direction of laminating plates (131, 132) and the other of the pair of laminating plates (132) thereof is integrally provided with a second projecting periphery (134) extending in the other direction of laminating the laminating plates (131, 132) so that the first and second projecting peripheries (133, 134) can overlap each other in parallel with the laminating directions of the laminating plates (131, 132) and the overlapping surfaces (133a, 134a) of the respective first and second projecting peripheries (133, 134) can be bonded to each other by soldering. As a result, the laminating plates (131, 132) can be bonded with sufficient bonding force without forming outwardly folded periphery surfaces.

  perpendicular to the stratification directions of these

  this. In addition, the outer wall surfaces of the laminating plates (131, 132) parallel to the laminating directions thereof (hereinafter called outer wall connecting surfaces) become flat, without the concave and convex parts, so that the seal assemblies (143) can be easily and firmly bonded by soldering to the bonding surfaces of exterior walls. Furthermore, even if the device has internal fins (111) in the exhaust gas passage (110) in order to improve the heat exchange efficiency, the exhaust gas circulates in the device practically in line. straight from the inlet (141) to the outlet (142) so that the loss of exhaust gas pressure can be reduced. There may be a case where the connecting surfaces of outer walls have relatively large concave and convex portions due to fluctuations in the manufacture and assembly of the laminating plates (131, 132). In addition, there may be another case where

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  the bonding surfaces of the seal assemblies (143) are bent by removal of the bonding surfaces of the seal assemblies

  seals (143) during a brazing treatment of these

  ci and relatively large spaces are formed between the bonding surfaces of exterior walls and bonding surfaces of the seal assemblies (143), thereby resulting in insufficient bonding of the seal assemblies (143) on the

  connecting surfaces of exterior walls.

  Therefore, it is preferable that a thin deformable metal plate (144) is disposed between each of the sets of seals (143) and that the first projecting periphery (133) and each of the sets of seals (143) are bonded to the plates. laminating (131, 132) via the thin deformable metal plate (144). In this case, the thin metal plate (144) acts as a seal (gasket) so that the connection surface of the seal assembly (143) and the external wall connection surface can adapt to the metal plate (144) so as to limit the spaces between them. As a result, the seal assembly (143) is reliably bonded by soldering to the outer wall bonding surface via the metal plate

(144).

  Preferably, the thin deformable metal plate (144) is provided at a periphery thereof with a wall surface (144a) extending in the directions of lamination of the lamination plates (131, 132). The wall surface (144a) serves as a guide plate for conveniently aligning the laminating plates (131, 132) when the laminating plates (131, 132) are stacked. Furthermore, it is preferred that the outermost laminating plates (135, 136) are provided at opposite front end level thereof with peripheral surfaces (135a, 136a) extending parallel to the directions of laminating the laminating plates (131, 132) and in directions deviating from each other. By bonding the respective seal assemblies (143) to the periphery surfaces (135a, 136a), a bonding force

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  higher seal assemblies (143) on the plates

  stratification (131, 132) can be ensured.

  In addition, preferably, each of the seal assemblies (143) is provided with a through hole (143a) communicating with the exhaust gas passages (110) and a lower interior surface (143b) of the through hole ( 143a) at least one of the seal assemblies (143) is located at a lower location than the lowest interior surface of the exhaust gas passages (110) so that water in which the of condensed exhaust gas can be drawn out of the gas passages

exhaust (110).

  Other characteristics and advantages of the present invention will be evaluated, as well as operating methods as well as the function of the related parts,

  from a study of the detailed description,

  appended claims and drawings which follow, the

  all is part of this request. In the drawings:

  Figure 1 is a simplified view of EGR systems.

  Figure 2 is a plan view of a heat exchange device for exhaust gas according to

  first embodiment of the present invention.

  Figure 3 is a cross-sectional view taken on

  along a line III-III in Figure 2.

  Figure 4 is a cross-sectional view taken on

  along a line IV-IV in Figure 2.

  Figure 5 is an enlarged view of an encircled part

indicated by A in Figure 4.

  Figure 6 is a cross-sectional view taken on

  along a line VI-VI in Figure 2.

  Figure 7A is a plan view of one of a pair of

laminating plates.

  Figure 7B is a cross-sectional view taken on

  along a line VIIB-VIIB of Figure 7A.

  Figure 8A is a plan view of the other of the pair

of laminating plates.

  Figure 8B is a cross-sectional view taken on

  along a line VIIIB-VIIIB of Figure 8A.

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  Figure 9A is a plan view of one of another

pair of laminating plates.

  Figure 9B is a cross-sectional view taken on

  along a line IXB-IXB in Figure 9A.

  Figure 10A is a plan view of the other pair of

laminating plates.

  Figure 0lB is a cross-sectional view taken on

  along a line XB-XB in Figure 10A.

  Figure 11 is an elevational view of the heat exchange device for exhaust gas according to

  first embodiment of the present invention.

  Figure 12A is a plan view of a set of seals. Figure 12B is an elevational view of the assembly of

joints.

  Figure 13 shows cross-sectional views

  of the pair of laminating plates before assembly.

  Figure 14 shows cross-sectional views

  of the pair of laminating plates after assembly.

  Figure 15 is a partial cross-sectional view of a heat exchange device for exhaust gas according to a second embodiment of the present invention. FIG. 16 is another partial view in cross section of the heat exchange device for exhaust gas according to the second embodiment of the

present invention.

  Figure 17 is an elevational view of a modified metal plate according to the second embodiment of

the present invention.

  Figure 18 is a partial cross-sectional view of a heat exchange device for exhaust gas according to a third embodiment of the present invention. FIG. 19A is a plan view of a heat exchange device for exhaust gas according to a

  fourth embodiment of the present invention.

  Figure 19B is a cross-sectional view of the heat exchange device for exhaust gas

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  according to the fourth embodiment of the present invention. Figure 20A is a plan view of a laminating plate according to the fourth embodiment of the present invention. FIG. 20B is an elevation view of the laminating plate according to the fourth embodiment of

the present invention.

  FIG. 21A is a plan view of a metal plate according to the fourth embodiment of the

present invention.

  Figure 21B is an elevational view of the metal plate according to the fourth embodiment of the present invention, and Figure 22 is a cross-sectional view of a heat exchange device for exhaust gas considered in comparison with the embodiments of the

present invention.

  Preferred embodiments of the present invention are described below as examples in which an exhaust gas heat exchange device (hereinafter referred to as a gas cooling system) 100 is applied to systems exhaust gas recirculation (hereinafter referred to as EGR) intended for engines with

  -25 internal combustion as shown in Figure 1.

  Part of the exhaust gas emitted by a diesel engine (called the engine below) 200 is recirculated to an intake side of the engine 200 by means of an exhaust gas recirculation nozzle 210,

as shown in figure 1.

  A well known EGR valve 220 is disposed in the exhaust gas recirculation manifold 210 and regulates an amount of EGR gas in accordance with the operation of the engine 200. The gas cooling system 100 is disposed in the exhaust gas recirculation manifold d 210 between an exhaust side of the engine 200 and the RGE valve 220 and is used to cool the RGE gas by heat exchange between the RGE gas and the water of

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  engine cooling (hereinafter called coolant). Next, a configuration of the gas cooling system 100 according to a first embodiment of the present invention is described with reference to Figures 2 to 6. In the gas cooling system 100, the EGR gas flows in a passage d exhaust 110 and a coolant circulates in a coolant passage 120, as shown in FIG. 4. The internal stainless fins 111 are arranged in the exhaust passage 110 in order to increase the surfaces with which the EGR gas comes into contact to promote heat exchange between the EGR gas and the coolant. The internal fins 111 are what are called offset type fins whose surfaces are offset relative to each other perpendicularly

in the direction of EGR gas circulation.

  After the internal fins 111 are arranged between a pair of laminating plates 131 and 132 so as to constitute a unit of laminating plates, a plurality of the laminating units are stacked one by one in the thickness directions thereof. ci (top and bottom directions in Figure 4) and the laminating plates 131 and 132 adjacent to each other, together with the internal fins 111, are bonded to each other by soldering using copper as the brazing material. The exhaust gas and coolant passages 110 and 120 are formed between two respective adjacent plates among the laminating plates 131 and 132. Therefore, as shown in Figures 3 and 6, the gas passages exhaust and coolant 110 and 120 extend respectively parallel to the plate surfaces of the laminating plates 131 and 132 (directions of the right and the

left on the drawings).

  Each of the laminating plates 131 and 132 is formed in a given shape, as shown in Figures 7 and 8, by stamping a thin stainless plate

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  almost rectangular in shape. One of the laminating plates 131 and 132 is provided integrally by stamping at a front end thereof with a first projecting periphery 133 projecting in one of the laminating directions (directions D) of the Laminating plates 131 and 132. Likewise, the other of the laminating plates 131 and 132 is provided in an integrated manner by stamping at a front end of the latter with a second projecting periphery 134 projecting into the other layering directions

  (directions D) of the laminating plates 131 and 132.

  The first and second projecting peripheries 133 and 134 overlap each other parallel to the laminating directions D of the laminating plates 131 and 132 and the overlapping surfaces 133a and 134a of the respective first and second projecting peripheries 133 and 134 are linked to each other by soldering. As shown in Figure 3, an exhaust inlet 141 for the introduction of EGR gas to the exhaust gas passages 110 and an exhaust outlet 142 for discharging the EGR gas from the exhaust gas passages 110 are

  formed in the first and second peripheries 133 and 134.

  When the first and second projecting peripheries 133 and 134 are linked, as shown in FIG. 4, the gas cooling system 100 is composed of gas cooling system core parts 101 constituting the passages for both gas exhaust and coolant 110 and 120 and constitutes a tank part 102 in which the core parts of the gas cooling system 101 are housed. The EGR gas flows mainly in a straight line direction in the gas cooling system 100 along the passageways

gas EGR 110.

  As indicated in FIGS. 9 to 11, each of the units of stratification plates formed by the stratification plates 131 and 132 comprising the inlet and the outlet of exhaust gases 141 and 142 is provided with notches 141a and 142a constituting the exhaust gas inlet and outlet 141 and 142. Joint assemblies 143 intended to connect 1il 2795811 respectively to the exhaust gas recirculation pipes (external pipes) 210 to the gas inlet and outlet exhaust 141 and 142 are linked to the first projecting periphery 133 of the laminating plate 131 adjacent to the inlet and to the

  exhaust gas outlet 141 and 142.

  As indicated in FIG. 12, each of the sets of seals 143 is made of stainless material and consists of a first square flange part 143a which has to be brazed to the first projecting periphery 133, a second flange part in diamond shape 143b to be fixed by bolts to the outer tube 210 and a protruding part (socket) 143c intended to position the set of seals relative to the inlet or the

  exhaust gas outlet 141 or 142.

  In addition, as shown in Figures 3 and 6, the gas cooling system 100 is provided with an inlet connection pipe 151 for introducing the coolant to the coolant passages 120 and a manifold outlet connection 152 intended to evacuate the coolant to the outside after heat is exchanged in the gas cooling system 100. According to the first embodiment, the first connection pipe 151 is disposed on the side of the exhaust gas outlet 142 and the outlet connecting pipe 152 is disposed on the side of the exhaust gas inlet 141 so that the coolant in the coolant passages 120 can flow in the opposite direction to the circulation of EGR gas in the gas passages

exhaust 110.

  Then, a method of manufacturing the

  gas cooling 100 is described.

  First of all, each of the laminating plates 131 and 132 (including the laminating plates comprising the notches 141a and 142a) is formed by stamping (method of machining by stamping) of a thin stainless plate, the front surfaces of which and rear are coated

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  (plated or clad) with brazing material

  (copper in this embodiment).

  Next, as shown in Figures 3 to 6, a plurality of units of laminating plates, each of which is constituted by the laminating plates 131 and 132, as shown in Figures 13 and 14, are laminated in the direction of the 'thickness of these (first temporary assembly treatment). The thickness of the laminating plates 135 and 136 located at the outermost opposite ends in the laminating directions D is greater than that of the other laminating plates 131 and 132, since the laminating plates 135 and 136 constitute the outer walls of the opposite front ends in the directions of

  stratification D of the gas cooling system 100.

  Then, the connecting pipes 151 and 152 are temporarily assembled to the laminating plate 135 and a pair of the sets of seals 143 is temporarily assembled to the first and second projecting peripheries 133 and 134 by inserting the projecting parts 143c in the inlet and the exhaust gas outlet 141 and 142, respectively (second temporary assembly treatment). The laminating plates 131 and 132, the laminating plates 135 and 136, the sets of seals 143 and the connecting pipes 151 and 152 are supported by templates after the second temporary assembly treatment and then are linked by brazing d '' a way constituted by a heating

  in an oven (soldering treatment).

  The gas cooling system 100 manufactured as mentioned above has the characteristics described below. One of the pair of laminating plates 131 of any of the laminating plate units is integrally provided with the first projecting periphery 133 extending in a laminating direction D of the laminating plates 131 and 132 and the other of the pair of lamination plates 132 thereof is integrally provided with the second projecting periphery (134) extending in the other lamination direction D of the

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  laminating plates 131 and 132 so that the first and second projecting peripheries 133 and 134 can overlap each other parallel to the laminating directions D, and the overlapping surfaces 133a and 134a of the respective first and second projecting peripheries 133 and 134 are bonded to each other by brazing. As a result, the laminating plates 131 and 132 can be bonded with sufficient bonding force without forming outwardly folded peripheral surfaces perpendicular to the laminating directions D. In addition, the outer wall surfaces of the laminating plates 131 and 132 parallel to the layering directions thereof (hereinafter called exterior wall bonding surfaces) become flat without the concave and convex portions so that the seal assemblies 143 can be easily and firmly bonded by

  soldering to the bonding surfaces of exterior walls.

  While the heat exchange efficiency of the gas cooling system 100 improves due to the fact that the gas cooling system 100 has the inner fins 111 in the exhaust gas passages 110, the EGR gas in the gas cooling 100 circulates practically in a straight line from inlet 141 to outlet 142 so that the pressure loss of the RGE gas

can be reduced.

  As shown in Figure 5, if a space g between a front end 133b of the first projecting periphery 133 of one of the laminating plates 131 and a base 133c of the first projecting periphery 133 of another of the laminating plates 131 is too small after the second temporary assembly treatment, the front end 133b and the base 133c interfere with each other because the brazing material coated on the laminating plate 131 or 132 is melted at the time of treatment brazing so that each length of the laminating plate 131

  or 132 depending on the thickness of the latter can be shortened.

  As a result, the inner fins 111 cannot be reliably linked to the laminating plates 131

and 132.

  On the other hand, if the space g between the front end 133b and the base 133c is too large after the second temporary assembly treatment, the space c always remains after the brazing treatment so that concave and convex parts can be formed on the bonding surfaces of

exterior walls.

  Therefore, the dimensions such as the height h of the inner fins 111 (see Figure 5) and the projection length L of the first projecting periphery 133 (see Figure 5) must be carefully defined with regard to reducing the length of the thickness of the laminating plate 131 or 132 during the treatment of

soldering.

  An exhaust heat exchange device according to a second embodiment of the present invention is described with reference to FIG. 15. According to the second embodiment, a thin deformable metal plate (stainless in this mode ) is arranged between each of the sets of seals 143 and the first projecting periphery 133 and is

  brazed to the outer wall bonding surface.

  Although the surfaces 133a and 134a of the first and second projecting peripheries 133 and 134 in parallel with the laminating directions D are linked to each other in order to flatten the bonding surfaces of external walls, there may be a cases where the connecting surfaces of external walls have relatively large concave and convex parts due to fluctuations in the manufacture and assembly of the plates

stratification 131 and 132.

  Furthermore, there may be another case where the connection surfaces of the seal assemblies 143 are curved, as indicated by a dashed line in FIG. 16, by a withdrawal of the connection surfaces of the seal assemblies 143 at the time of brazing treatment and relatively large spaces are formed between the bonding surfaces of exterior walls and the surfaces of

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  connection of the seal assemblies 143, thus resulting in insufficient connection of the seal assemblies 143 on the

  connecting surfaces of exterior walls.

  Therefore, in the case where the thin deformable metal plate 144 is disposed between each of the sets of seals 143 and the first projecting periphery 133 and o each of the sets of seals 143 is linked to the laminating plates 131 and 132 through of the thin deformable metal plate 144, the thin metal plate 144 acts as a seal (gasket) so that the connection surface of the seal assembly 143 and the external wall connection surface can adapt to the metal plate 144 so as to limit the spaces between them. As a result, the seal assembly 143 is bonded firmly by soldering to the outer wall bonding surface through the metal plate 144 so that the reliability of the gas cooling system

may increase.

  As shown in Figure 17, the thin plate 144 can be folded in a wave shape to reach the goal

of the second embodiment.

  A gas cooling system 100 according to a third embodiment of the present invention is

  described with reference to Figure 18.

  In accordance with the third embodiment, as shown in FIG. 18, one of the seal assemblies 143 is provided with a through hole 143a communicating with the exhaust gas passages 110 and a lowest interior surface 143b of the hole through 143a is located at a location lower than a lower interior surface of the exhaust gas passages 110 so that water in which the moisture of the EGR gas has condensed can be entrained outward gas passages

exhaust 110.

  Although Figure 18 shows only the configuration on the side of the exhaust gas inlet 141, a lower interior surface 143b of the through hole 143a on the side of the exhaust gas outlet 142 can also be located at level of a location lower than the surface

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  lowest interior of the exhaust gas passages 110. A gas cooling system 100 according to a fourth embodiment of the present invention is described with reference to the figures in Figures 19A and 19B. According to the fourth embodiment, a height hi of the core part of the gas cooling system 101 (dimension in parallel with the laminating directions B) is practically equal to a length of height h2 of the gas inlet d ' exhaust 141

  or from the exhaust gas outlet 142.

  As shown in Figures 19A, 19B, 20A and 20B, the outermost lamination plates 135 and 136 of the lamination plates 131 and 132, which constitute the exterior walls of the gas cooling system 100, are provided at the opposite longitudinal front ends thereof folded portions 137 having periphery surfaces 135a and 136a extending in parallel with layering directions D and in directions away from one

  the other (top and bottom directions in Figure 19B).

  In addition, the metal plate 144 is provided at the opposite peripheries thereof perpendicular to the laminating directions D with folded parts 114b each having a wall surface 144a extending in the laminating directions D, as shown in the figures 19A, 19B, 21A and 21B. The length of height h3 of each of the folded parts 144b (dimension in parallel with the laminating directions D) is practically equal to the length h4 between the opposite front ends of the folded parts 137 provided on the laminating plates

and 136.

  As mentioned above, when the wall surfaces 144a extending in the laminating directions D are provided on the plate 144, the wall surfaces 144a serve as guide surfaces for conveniently aligning the plates laminating 131 and 132 when the laminating plates 131 and 132 are

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  laminates at the time of the first temporary assembly treatment. Furthermore, since the plates 135 and 136 are provided with the peripheral surfaces 135a and 136a extending in opposite directions towards the outside from the core parts of the gas cooling system 101, the contact surfaces o the plates 144 come into contact with the core parts of the gas cooling system 101 become wider. Then, the seal assemblies 143 can be linked to the laminating plates 135 and 136

  with greater bond strength.

  In accordance with the embodiments mentioned above

  above, the gas cooling system 100 is applied to the heat exchanger intended for RGE gas circulation systems. However, the gas cooling system can also be applied to other heat exchangers such as a heat exchanger to be arranged in an exhaust silencer in order to collect the thermal energies of the exhaust gases. Furthermore, although the gas cooling system 100 includes the plates 144 according to the third embodiment, the peripheral surfaces 135a and 136a of the laminating plates 135 and 136 can be applied to the gas cooling system 100 without the plates 144 as shown in the first

embodiment.

  Furthermore, in accordance with the fourth embodiment, the height hi of the core part of the gas cooling system 101 is practically equal to the height length h2 of the exhaust gas inlet 141 or the gas outlet exhaust 142. The peripheral surfaces 135a and 136a can be applied to the gas cooling system where the height hl of the core part of the gas cooling system 101 is greater than the height length h2 of the inlet exhaust gas 141 or exhaust gas outlet 142, as shown

  in the first embodiment.

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Claims (7)

  1. An exhaust gas heat exchange device for exchanging heat between an exhaust gas and a coolant comprising a plurality of units, each of which consists of a pair of laminating plates ( 131, 132), laminated and linked by brazing to each other, exhaust gas passages from the passages (110) and coolant passages (120) arranged between two respective stratification plates among the plates stratification (131, 132), internal fins (111) arranged at at least one of the exhaust gas passages (110) and the coolant passages (120), of an inlet (141) and an exhaust gas outlet (142) arranged on opposite sides of the exhaust gas passages (110) and a pair of seal assemblies (143) linked to the laminating plates ( 131, 132) at the inlet (141) and the outlet (142) of exhaust gas for connecting external pipes (210) to the exhaust gas passages (110) so as to circulate the exhaust gas perpendicular to the directions of lamination of the lamination plates (131, 132) from one of the pair of seal assemblies (143) via the exhaust gas inlet (141), the exhaust gas passages (110) and the exhaust gas outlet (142) to the other of the pair of seal assemblies (143), characterized in that: one of the pair of laminating plates (131) of any of the units is integrally provided with a first projecting periphery (133) extending in a first laminating direction of the laminating plates (131, 132), and the other of the pair of laminating plates (131) thereof is integrally provided with a second periphery projection (134) extending in the other direction of laminating the laminate plates ication (131, 132) so that the first and second projecting peripheries (133, 134) can be 19 2795811   overlapping each other in parallel with the layering directions of the layering plates (131, 132) and the overlapping surfaces (133a, 134a) of the respective first and second projecting peripheries (133, 134) can be bonded one to the other by soldering. 2. Device according to claim 1, further comprising: a thin deformable metal plate (144) disposed between each of the sets of seals (143) and the first projecting periphery (133), in which each of the sets of seals (143) is linked to the laminating plates (131, 132) via the thin metal plate deformable (144).   3. Device according to claim 2, wherein the thin deformable metal plate (144) is provided at a periphery thereof with a wall surface (144a) extending in the directions of stratification of the plates stratification (131, 132).   4. Device according to claim 1, 2 or 3, in which the outermost laminating plates (135, 136) are provided at their opposite front ends with peripheral surfaces (135a, 136a) extending in parallel with the layering directions of the layering plates (131, 132) and in directions deviating from each other, each of the joint assemblies (143) being brazed to the surfaces of periphery (135a, 136a).   5. Device according to any one of the claims   1 to 4, in which each of the sets of seals (143) is provided with a through hole (143a) communicating with the exhaust gas passages (110) and a lower interior surface (143b) of the through hole ( 143a) at least one of the seal elements (143) is located at a location lower than the lowest interior surface of the exhaust gas passages (110) so that water 2795811   in which the humidity of the exhaust gas has condensed can be entrained towards the outside of the gas passages exhaust (110).   6. An exhaust gas heat exchange device for exchanging heat between an exhaust gas and a coolant comprising a plurality of units, each of which consists of a pair of laminating plates ( 131, 132), laminated and linked by brazing to each other, exhaust gas passages (110) and coolant passages (120) arranged between two respective adjacent stratification plates among the stratification (131, 132), internal fins (111) arranged at at least one of the exhaust gas passages (110) and the coolant passages (120), an inlet (141) and an exhaust gas outlet (142) disposed on opposite sides of the exhaust gas passages (110) and a pair of seal assemblies (143) connected to the laminating plates (131, 132 ) at the inlet (141) and the outlet (142) of exhaust gas view of connecting external pipes (210) to the exhaust gas passages (110) so as to circulate the exhaust gas perpendicular to the laminating directions of the laminating plates (131, 132) from one of the pair seal assemblies (143) through the exhaust gas inlet (141), the exhaust gas passages (110) and the exhaust gas outlet (142) to the another of the pair of seal assemblies (143), characterized in that * 30 the outermost lamination plates (135, 136) are provided at opposite front ends thereof with periphery (135a, 136a) extending in parallel with the laminating directions of the laminating plates (131, 132) and in directions deviating from each other, in which each of the sets of seals (143) is bonded directly or indirectly by soldering to the periphery surfaces (135a, 136a). 2 1 2795811   7. Device according to claim 6, in which one of the pair of laminating plates (131) of any one of the units is integrally provided with a first projecting periphery (133) extending in a first laminating direction of the laminating plates (131, 132) and the other of the pair of laminating plates (131) thereof is integrally provided with a second projecting periphery (134) extending in the further laminating direction of the laminating plates (131, 132) so that the first and second projecting peripheries (133, 134) can overlap each other in parallel with the laminating directions of the laminating plates (131, 132) and the overlapping surfaces (133a, 134a) of the respective first and second projecting peripheries (133, 134) can   be bonded to each other by soldering.