KR20190136993A - Heat exchanger for gases, especially exhaust gases of an engine - Google Patents

Abstract

The present invention relates to a heat exchanger for gas, especially exhaust gas of an engine of a vehicle. The heat exchanger comprises: a tube bundle or a plate arranged in a housing (2) formed by two hollow portions (2a, 2b) including corresponding adhesion surfaces on surrounding edges thereof and facing each other, and coupled by the adhesion surfaces thereof in a first and a second adhesion zone forming a first and a second solder joint (4); manifolds (6a, 6b) inside ends of the housing (2); and gas tanks (3a, 3b) connected to the tube bundle or the plate, overlapped on an outer surface of the housing, and joined to the hollow portions (2a, 2b) of the housing by the solder joints. The two hollow portions (2a, 2b) of the housing, two gas tanks (3a, 3b), and two manifolds (6a, 6b) are made of an aluminum-based material. The solder joints for the hollow portions (2a, 2b) of the housing and the solder joints between the hollow portions (2a, 2b) of the housing and the gas tanks (3a, 3b) are simultaneously manufactured.

Description

Heat exchanger for gases, especially engine exhaust gases {HEAT EXCHANGER FOR GASES, ESPECIALLY EXHAUST GASES OF AN ENGINE}

The present invention relates to a heat exchanger for gas, in particular for exhaust gas of an engine of an automobile, comprising a tube bundle or a heat exchange plate disposed inside the hermetic housing and each manifold of the end of the housing. More particularly, the invention relates to a type of heat exchanger having each gas tank connected to a tube or plate.

Exhaust gas recirculation (EGR) in automobiles redirects a portion of the exhaust gases of the combustion engine towards the intake manifold, since the presence of exhaust gases in the mixture reduces the production of nitrogen oxides (NOx). It is a system that has been used for many years to mix it with intake air.

EGR systems operate primarily at low engine loads and low speeds. The proportion of gas that is recycled makes it suitable for each engine according to pollution standards to ensure a balance between the emissions of nitrogen oxides and particulates.

Basically, the system for the control of pollution by exhaust gas recirculation is a pipe that sends exhaust gas to the intake manifold, and a heat that cools the burned gas and is installed in the loop of the EGR system, improving the efficiency of the system. It is manufactured with an exchanger (EGRC or "Exhaust Gas Recycling Cooler") and with a valve that controls the movement of the exhaust gases through.

Heat exchangers, in particular chillers of the EGRC type, may have separate configurations. Heat exchangers for exhaust gases of engines of automobiles are known to comprise the elements described in the preamble of claim 1 of the present invention. That is, the heat exchanger

An assembly of a heat transfer element (formed by a tube bundle or by a plate) designed for circulation of the exhaust gas, the heat transfer occurring with the combusted exhaust gas of the combustion engine of the vehicle;

A hollow elongated housing (also known as a shell) extending longitudinally, the front end and the rear end of which are open, the interior of the housing receiving the tube bundle and defining the outer tube to the manifold; Refrigerant circulates through;

First and second support plates (known as manifolds), each supporting plate being coupled to a gas inlet end and a gas outlet end of the housing, the ends of the heat transfer element of the assembly of the heat transfer element being Fixed to the first and second plates, such that the ends remain in communication with the outside of the housing through the through opening; And

First and second gas tanks connected to the tube, each gas tank being respectively coupled to an outer portion of each manifold;

It includes.

Up to now, EGRC type coolers have been mostly made of stainless steel due to the mechanical and chemical requirements of the field requiring materials of high resistance to corrosion and to mechanical forces.

In order to simplify the problem at this point, an EGRC type cooler is always included but is simply described by reference to "cooler" or "heat exchanger".

In order to reduce the cost and weight of chillers, aluminum has recently been used as an alternative to stainless steel in the manufacture of various parts of the chiller.

During assembly of the cooler, the various parts of the cooler must be joined together. One of the most commonly used techniques for this is brazing.

Although aluminum heat exchangers for use in the automotive industry are generally manufactured by controlled atmosphere brazing ("CAB") (main method) and secondaryly by vacuum brazing, the various brazing processes are made of aluminum. It has been used commercially to make exchangers. Brazing of the "CAB" type is made under a controlled atmosphere which typically consists of nitrogen containing the least amount of oxidative contaminants (mainly oxygen, gas and water vapor).

The material required to perform the brazing of aluminum ("CAB" type or vacuum type) is generally a multilayer material, where the filler material for creating the joint is laminated with the core material to form a single sheet of multilayer material.

One of the main parts of the chiller is the housing, which represents an elongated and hermetically sealed body, each end of which is open to receive a tube therein, the function of which is to allow the circulation of the refrigerant inside the chiller. And an assembly of tubes or plates used in the gas circuit. The housing is typically rectangular or circular in shape, but may be irregular if necessary to increase its capacity. Thus, the shape of the housing determines the cross section and hence the amount of heat transfer element (tube or plate).

The main disadvantage of using a multilayered material of aluminum for the manufacture of the housing of the cooler is the difficulty of forming a tube with a closed part, or a single part, such as a hermetic housing. The housing also generally includes refrigerant flanges and other stamping areas that are not easy to seal in closed parts.

Therefore, to provide an alternative to the prior art and to solve the disadvantages, it is necessary to provide a heat exchanger for an exhaust gas of an engine manufactured by brazing of all parts having low weight, low cost and optimum quality.

It is an object of the present invention to provide a heat exchanger for exhaust gas of an engine which solves the above mentioned disadvantages and provides the advantages described below.

The present invention therefore relates to a heat exchanger for gases, in particular for exhaust gases of combustion engines.

An assembly of heat transfer elements (formed by tube bundles or plates) designed for circulation of the exhaust gases;

An elongate housing extending longitudinally and longitudinally, each opposing end being open, the interior of the housing receiving the heat transfer element;

First and second manifolds, each manifold coupled to a gas inlet end and a gas outlet end of the housing, each manifold disposed inside each end of the housing, the heat transfer of the assembly of heat transfer elements; An end of the element is secured to the first and second manifolds; And

First and second gas tanks connected to the transfer element, each gas tank being coupled to an outer portion of each manifold, respectively;

It includes.

Unlike heat exchangers known in the art, the heat exchangers proposed by the present invention are distinguished in the following respects:

The housing is formed of two hollow parts,

The two housing parts have corresponding adhesive surfaces at their respective peripheral edges,

The two housing parts are disposed towards each other and joined by their respective adhesive surfaces in the first and second adhesive zones forming the first and second brazing joints,

Each gas tank is superimposed on the outer surface of the housing and joined by each brazing joint to each housing part,

Two housing parts, two gas tanks and two manifolds are made of aluminum-based material

Brazing joints of the two housing parts to each other and of the housing part and each gas tank are produced simultaneously (in brazing of the entire assembly of the heat exchanger).

This advantageous solution of dividing the aluminum housing into two parts which are manufactured separately and joined by their corresponding adhesive surfaces during the assembly phase of the entire cooler, and forming the first and second brazing joints, results in a complete and rapid formation of the housing. The assembling step is very simple since all brazing joints of all parts of the cooler are manufactured at the same time, while also ensuring complete and rapid adhesion between the half shell and the gas tank.

According to one preferred embodiment, each of the two housing portions comprises a hollow shell body having a continuous surface of U-shaped cross section with a top surface, a bottom surface and a lateral surface joining the top and bottom surfaces together. On the other hand, the upper and lower surfaces have respective peripheral longitudinal edges. The two housing parts are disposed in the heat exchanger towards each other by their respective peripheral longitudinal edges, joined by two bonding surfaces joined by brazing, one of the two bonding surfaces being on the upper part and the other one. Is located on the lower part.

The two housing parts have similar configurations and dimensions, but these two housing parts are refrigerant through the interior of the housing in contact with the heat transfer element of the tube bundle for the exchange of heat with the exhaust gas circulating through the heat transfer element. Different elements may be provided, depending on the type of housing, such as inlet and outlet openings for refrigerant fluid for circulation of the fluid.

With respect to the adhesive surface between the two housing parts forming the brazing joint, in the first embodiment, these adhesive surfaces are longitudinal strips which overlap on the peripheral edge of the other housing part at each of the peripheral edges of the two housing parts. It can also be formed by, thereby forming a brazing joint of overlapping type.

The overlapping strip occupies only the central portion of the longitudinal bonding zone between the edges of the housing portion, so that there may be no overlapping strip at the two front and rear ends of the bonding zone. Each extension is formed in these end zones extending laterally without overlapping strips from the housing portion located in the lower portion of the overlap in the transverse direction towards the other housing portion.

An inner longitudinal cavity is formed in the lower portion of the overlapping strip of the overlapping housing portion that is not covered by the other housing portion to allow for cancellation of the tolerance of the part and ensure that the overlap has the minimum brazing area. This cavity is closed by an integral part of the gas tank, which covers the cavity.

Alternatively, instead of using an overlapping type of adhesive surface between the housing parts, other equivalent solutions for the brazing joint of the two housing parts may be used.

In another possible embodiment of the invention, the adhesive surface for the brazing joint between the two housing parts can be formed by each upward extension of the peripheral edge. The peripheral edges of the respective housing parts can also simply butt against one another. The peripheral edge may also have a rolling feature or complementary zigzag surface.

Optionally, additional elongate elements may be added to the top of the adhesive zone, which is likewise made of aluminum, for any of the adhesive surface options. The further elongate element has a sufficient length to cover at least a substantial portion (at least at least ¾ of the total length) of the adhesive zone between the portions.

Although the present invention has proposed separate features of the adhesive surface between the two housing parts, the design of these features can be realized only if they are satisfactory for use with a multilayer sheet of material, i.e. aluminum, for the production of the housing and the gas tank. .

That is, preferably all parts (housings, inner tubes or plates, gas tanks and manifolds) are made of multilayered aluminum. The multilayer aluminum is preferably composed of a sheet having at least two superimposed layers of aluminum, one layer of core material and the other layer of brazing material. It may also be provided with other additional protective layers. The core material may be aluminum of series 3000, the brazing material may be aluminum of series 4000, and the protective material may be aluminum of series 1000. Although the brazing layer should always be on the surface of the material on either the inner side or the outer side, the sequence of the different layers can vary widely.

The gas tank and half shell have a filler material located on the inner face of the part.

Aluminum offers many advantageous features for heat exchangers such as:

Lightweight design;

Highly automated and safe brazing process;

High thermal conductivity even when bonded by brazing;

Corrosion resistance;

Good formability;

Adequate strength to withstand temperature and pressure cycles; And

Ease of recycling, a solution that respects the environment

To provide.

Multilayer aluminum materials used for the production of the different parts of the present invention include heat treatable or non-heat treatable aluminum alloys having a coating relationship, sheet thickness and width, depending on the specifications of each particular situation.

With respect to the gas tank, in one preferred embodiment when using a brazing joint of overlapping type with respect to the housing, an opening or cutout designed for the positioning of the final part of the overlapping strip is provided at the coupling edge to the housing. Preferably, the opening is provided for each of the two brazing joints. In addition to enabling insertion of half shells in the tank, the openings make it possible to close the potential cavities between the half shells.

With respect to each manifold, these manifolds have peripheral edges extending in the longitudinal direction and outward of the heat exchanger.

The invention can be used in either a heat exchanger with a tube bundle or a heat exchanger with a plate.

BRIEF DESCRIPTION OF DRAWINGS To better understand what is mentioned, the accompanying drawings are drawn to illustrate certain circumstances of different embodiments and are shown only by way of non-limiting example.
FIG. 1 is a perspective view identical to FIG. 2 with the gas tank already positioned at the final working position on the housing. FIG.
1b shows the positioning of the peripheral edge of the gas tank.
2 is a perspective view of one possible embodiment of a hermetic housing with two manifolds, with two gas tanks facing each other.
3 is a perspective view of a possible embodiment of a hermetic housing consisting of two housing parts surrounding a tube, with each manifold located at each end of the housing.
Figure 3b shows in detail one of the adhesive zones between the housings in an overlapping form.
3C is a schematic side view of one of the adhesive zones between housings in an overlapping form;
4 is a perspective view of a second embodiment of a hermetic housing, in which two housing portions each have a flat peripheral edge;
5 is a perspective view of a third embodiment of a hermetic housing.
6 is a perspective view of a fourth embodiment of a hermetic housing in which two housing portions are joined by a joint in the form of a vertical extension;
7 is a perspective view of a fifth embodiment of a hermetic housing in which two housing portions are joined by a joint in the form of a rolling;
8 is a perspective view of a sixth embodiment of a hermetic housing in which two housing portions are joined by a joint having a complementary zigzag surface.
9 is a perspective view of a seventh embodiment of a hermetic housing in which two housing parts are joined by a joint with straight peripheral edges butted against each other and also by an external element.
10 is a perspective view of an eighth embodiment of a hermetic housing in which two housing parts are joined in a similar manner to the first embodiment and also by means of fastening elements in the form of overlapping joints.
11A-11C show various views of one possible embodiment of one of the two housing portions, in which FIG. 11A is a perspective view, FIG. 11B is a side view, and FIG. 11C is a front view.
12A-12D show various views of one possible embodiment of a gas tank, FIG. 12A is a perspective view, FIG. 12B is a front view, FIG. 12C is a side view, and FIG. 12D is a cross-sectional view taken along the line AA of FIG. 12C.

Some exemplary embodiments of the invention will be described below with reference to FIGS. 1 to 12.

As shown in Figures 1 and 2, the present invention relates to a heat exchanger for gases, in particular for the exhaust gases of an engine:

An elongate body-shaped housing 2 extending longitudinally and longitudinally, respectively open at opposing fronts and rears (inlets and outlets) and receiving heat transfer elements (not shown) therein; The housing 2 is formed by two separate hollow parts 2a, 2b, which two hollow parts 2a, 2b comprise corresponding adhesive surfaces at their respective peripheral edges, and the two housing parts 2a, 2b ) Are disposed towards each other and joined by their respective bonding surfaces in the first and second bonding zones 4 forming the first and second brazing joints;

First and second manifolds 6a, 6b, each manifold being coupled to a gas inlet end and a gas outlet end of the housing 2, respectively, wherein the ends of the heat transfer element of the assembly of the heat transfer element are Fixed to the first and second manifolds; And

First and second gas tanks 3a, 3b connected to the transfer element, each gas tank 3a, 3b being respectively coupled to an outer portion of each manifold 6a, 6b, each gas tank 3a 3b is superimposed on the outer surface of the housing 2 and joined by respective brazing joints to the respective hollow portions 2a, 2b of the housing;

Including;

Two housing parts 2a, 2b, two gas tanks 3a, 3b and two manifolds 6a, 6b are made of an aluminum based material

Brazing joints of the two housing parts 2a, 2b to each other and brazing joints of the housing parts 2a, 2b and each gas tank 3a, 3b are produced simultaneously.

In the accompanying drawings, the inner heat exchange tube or plate is not shown because it is entirely covered by the hermetic housing 2.

1 and 1 b, each opening 5a, 5b is provided at each gas tank 3a for positioning and joining of the final part of the overlapping strip 2a ′ at the already assembled position of the heat exchanger. , 3b) is formed on one side of the peripheral coupling edge 10a. Figure 1b shows in detail how the peripheral edge 10a of the gas tank 3a is machined to have said opening 5a, in this case a rectangular opening.

2, a heat exchanger for the same gas is shown, but just before installing one of the two gas tanks 3a on the housing parts 2a, 2b, one of the two manifolds 6a. You can see a part of).

1, 2, 3, 3A, 3B and 3C, a first embodiment of the present invention is shown, wherein each housing portion 2a, 2b has an upper face, a lower face and a side. It has a hollow main body having a U-shaped cross section having a directional face. In this first embodiment of the invention, the corresponding adhesive surfaces in the adhesive zones of the two housing parts 2a, 2b are overlapped strips 2 provided on the peripheral edge of one of the two housing parts 2a, 2b. ') Is formed by overlapping on the peripheral edge of the other housing part 2', thereby forming a brazing joint of the overlapping type.

In particular with reference to FIG. 10, although this same first embodiment is shown, a further specific fastening means 13 (eg riveting without a TOX type rivet) is fixed to the brazing joint between the housings so that Reinforce the joint. Other types other than screws can similarly be used.

In particular with respect to FIGS. 3B and 3C, it is shown how the overlapping strip 2 ′ occupies only a certain part of the entire length of the adhesive zone 4 between the peripheral edges of the housing parts 2a, 2b, and the As a result a space is formed without overlapping strips 2 'at the two ends, front and back of the adhesive zone, and each extension 7 extends from the housing part located in the lower part of the overlapping part in the transverse direction to the other housing part ( In detail in these end zones extending laterally without overlapping strip 2a '. 11A-11C show one possible embodiment of the half shell 2b according to this particular configuration. It has a U-shaped configuration, and on each end surface of "U", each overlapping strip 2 'extending in the form of a descending step (see FIG. 11C) is formed.

4 to 10 show another possible embodiment of the adhesive surfaces between the sealed housing parts 2a, 2b.

In particular, in FIG. 4, the adhesive surfaces between the parts 2a, 2b are formed by the actual rectangular peripheral edge 8 of each housing part 2a, 2b, which is abutted against each other and joined by a brazing joint. have. Thus, these joints do not protrude high beyond the rest of the housing portions 2a, 2b.

FIG. 5 is a variant embodiment of FIG. 4, wherein the two housing parts 2a, 2b have some manifolds 10 at their respective peripheral edges, so that one of the edges is of the surface of the other edge. Only the upper portion located on the top has an elongate longitudinal portion, while the other edge has a concave longitudinal surface to receive the elongated portion of the first edge at the top of the surface. In this way, the joint in this case does not protrude too high beyond the rest of the housing surface.

6 shows another configuration in which the adhesive surfaces are formed by respective longitudinal extensions 7 extending vertically upwards from each peripheral edge of both parts 2a and 2b. The extensions 7 are joined together by their respective facing inner surfaces by brazing joints.

FIG. 7 shows another configuration in which the adhesive surfaces are formed by respective rolled features 9 which extend from their respective peripheral edges and are rolled and joined by brazing joints.

FIG. 8 shows another configuration in which the adhesive surfaces are formed by complementary zigzag surfaces 12 joined by brazing joints.

9 shows another configuration in which the additional elongate element 11 is fixed on the top of the adhesive zone 4 and incorporated (by any known means). The elongate element has a sufficient length to cover at least ¾ of the total length of the adhesive zone between the housing portions 2a, 2b.

10 shows another configuration in which the two housing parts are joined in an overlapping joint and also by means of fastening means 13 in a manner similar to the first embodiment.

12A-12D are various views of one possible embodiment of one of the two gas tanks 13b. The illustrated gas tank 3b has a conventional hollow shape that is tapered to form a circular opening, the joining edge being opposite to the opening, where the joining edge is a flat edge, two large bases, and two small It has a substantially rectangular configuration with a base. In addition, each central opening 5b disposed respectively in the center of the peripheral edges 6a, 6b of each large engagement base of each gas tank 3a, 3b for positioning of the final part of the overlapping strip 2a '. ) Is distinguished. In this case, another second opening 5b 'is provided in one of the large bases.

Although specific embodiments of the present invention are referenced, many variations and modifications of the described heat exchangers for gases are possible and all other details are described without departing from the scope of protection as defined by the appended claims. It will be apparent to those skilled in the art that equivalents may be substituted.

Claims (15)

As a heat exchanger 1 for a gas, in particular an exhaust gas of a combustion engine,
An assembly of heat transfer elements designed for circulation of the exhaust gas;
An elongate housing 2 extending longitudinally and longitudinally and open at each opposing end, the interior of the housing receiving the heat transfer element;
First manifold 6a and second manifold 6b, each manifold being coupled to a gas inlet end and a gas outlet end of the housing, each manifold 6a, 6b being at each end of the housing; Disposed inwardly, wherein ends of the heat transfer element of the assembly of the heat transfer element are secured to the first and second manifolds; And
A first gas tank 3a and a second gas tank 3b connected to the heat transfer element, each gas tank being coupled to an outer portion of each manifold 6a, 6b, respectively;
In the heat exchanger (1) comprising:
The housing 2 is formed of two hollow parts 2a, 2b,
The two housing parts 2a, 2b have corresponding adhesive surfaces at their respective peripheral edges,
The two housing parts 2a, 2b are disposed towards each other and joined by their respective adhesive surfaces in the first and second adhesive zones 4 forming the first and second brazing joints,
Each gas tank 3a, 3b is superimposed on the outer surface of the housing and joined to each housing portion by respective brazing joints,
Two housing parts 2a, 2b, two gas tanks 3a, 3b and two manifolds 6a, 6b are made of an aluminum based material
The brazing joint of the two housing parts 2a, 2b to each other and the brazing joints of the housing parts 2a, 2b and each gas tank 3a, 3b are produced simultaneously
heat transmitter. The method of claim 1,
The heat transfer element of the assembly of heat transfer elements is formed by a tube bundle
heat transmitter. The method of claim 1,
The heat transfer element of the assembly of heat transfer elements is formed by a plate
heat transmitter. The method according to any one of claims 1 to 3,
Each housing part 2a, 2b is characterized by having one continuous hollow body having a U-shaped cross section having an upper face, a lower face and a lateral face.
heat transmitter. The method according to any one of claims 1 to 4,
The corresponding adhesive surface of the two housing parts 2a, 2b is provided at the peripheral edge of one of the two housing parts 2a, 2b and overlaps the overlapping strip 2a 'on the peripheral edge of the other housing part 2b. ), Characterized in that to form a brazing joint of the overlapping type
heat transmitter. The method of claim 5,
The overlapping strip 2a 'occupies only the central portion of the adhesive zone between the peripheral edges of the housing parts 2a, 2b so that there are no overlapping strips 2a' at the two ends, front and back of the adhesive zone, Each extension is formed in these end zones extending transversely without overlapping strips 2a 'from the housing part located in the lower part of the overlap in the transverse direction towards the other housing part.
heat transmitter. The method of claim 6,
The openings 5a, 5b are characterized in that they are provided at the peripheral edges 6a, 6b of the coupling of each gas tank 3a, 3b for positioning of the final part of the overlapping strip 2a '.
heat transmitter. The method according to any one of claims 1 to 4,
The adhesive surface for the two brazing joints between the two housing parts 2a, 2b is characterized by being formed by each upward vertical extension 7 of each peripheral edge.
heat transmitter. The method according to any one of claims 1 to 4,
The adhesive surface for the two brazing joints between the two housing parts 2a, 2b is formed by the straight peripheral edges of each housing part against each other.
heat transmitter. The method according to any one of claims 1 to 4,
The adhesive surface for the two brazing joints between the two housing parts 2a, 2b is formed by a rolling feature
heat transmitter. The method according to any one of claims 1 to 4,
The adhesive surface for the two brazing joints between the two housing parts 2a, 2b is formed by a complementary zigzag surface
heat transmitter. The method according to any one of claims 1 to 11,
The further elongate element is incorporated on the top of the adhesive zone, characterized in that it is made of aluminum with a sufficient length covering at least ¾ of the total length of the adhesive zone between the housing parts 2a, 2b.
heat transmitter. The method according to any one of claims 1 to 12,
Each said manifold 6a, 6b is characterized by having a peripheral edge extending in the longitudinal direction of the heat exchanger 1 and outwardly.
heat transmitter. The method according to any one of claims 1 to 13,
The housing 2, tube or plate, gas tanks 3a, 3b and manifolds 6a, 6b comprise at least two superimposed layers of aluminum of one layer of core material and the other layer of brazing material. Made of multi-layered aluminum formed by sheets, which may also have other additional protective layers, said brazing layer being disposed on the surface of the material on either the inner or outer side.
heat transmitter. The method of claim 14,
The gas tanks 6a, 6b and the housing parts 2a, 2b are characterized in that they have filler material located on the inner face of the part.
heat transmitter.

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