EP3019808A1

EP3019808A1 - Heat exchanger

Info

Publication number: EP3019808A1
Application number: EP14739724.4A
Authority: EP
Inventors: José Antonio DE LA FUENTE ROMERO; Yolanda Bravo; Anne-Sylvie Magnier-Cathenod; Carlos Martins
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2013-07-12
Filing date: 2014-07-04
Publication date: 2016-05-18
Anticipated expiration: 2034-07-04
Also published as: WO2015004032A1; US20160327344A1; CN105473975A; JP6355730B2; FR3008485A1; KR20160032097A; KR101814027B1; CN105473975B; JP2016524119A; EP3019808B1; FR3008485B1

Abstract

The present invention relates to a heat exchanger for exchanging heat between first and second fluids, said exchanger including: a casing and an exchange bundle positioned inside said casing, wherein the exchange bundle includes: a main surface which has a main width and which consists of a plurality of tubes suitable for guiding the first fluid inside said tubes; an intake of the first fluid toward an outlet of the first fluid, making it possible to guide, outside of said tubes, the second fluid; an intake of the second fluid toward an outlet of the second fluid; wherein the tubes are, at least at one first end, assembled such as to form a secondary surface having a secondary width which is smaller than the main width for coupling with the intake and/or the outlet of the first fluid; wherein the secondary surface at the first end of the tubes is formed such as to create a space between the casing and the outer surface of the secondary surface, said space being connected to the intake and/or the outlet of the second fluid.

Description

HEAT EXCHANGER

Field of the invention

The present invention relates to a heat exchanger, such as a heat exchanger for a motor vehicle. The heat exchanger according to the present invention is particularly suitable for use in the engine exhaust pipes. This type of heat exchanger is usually called Exhaust Gas Recirculation Cooler (EGR) or EGRC.

A heat exchanger, of the type used in the automotive industry, and more specifically inside the exhaust ducts of an internal combustion engine, comprises in principle a housing or casing comprising, in its inside, heat exchange elements allowing heat exchange from a first fluid to a second fluid. These elements, allowing this heat exchange can, for example, include tubes.

These tubes located inside a heat exchanger may be present within an exchange beam comprising a plurality of tubes arranged substantially parallel to each other. The tubes may be positioned in a row or several rows parallel to each other. The tubes make it possible to guide the first fluid inside said tubes, from a first end of the exchange bundle to the second end of the exchange bundle.

The tubes considered together define between them channels which guide the second fluid of the second end of the heat exchanger to the first end of the heat exchanger. Thus, a heat exchanger allows in particular the circulation, against the current, of a first and a second fluid within this heat exchanger. Other elements such as plates, vanes and flow interferers may be provided in addition to these tubes forming the exchange bundle in order to improve the heat exchange between the first and the second fluid.

Heat exchangers comprising a casing for receiving, in its interior, exchange beams are known from the prior art. The housing is in the form of a housing comprising a plurality of walls forming the outside of the housing and defining the volume in which the heat exchange takes place. The housing is, in principle, provided with inlets and outlets for the first and second fluid at a first and a second end of the housing. These inputs and outputs thus allow the heat exchanger to be connected respectively to inlet ducts and outlet ducts adapted to conduct the first and second fluids in the direction of the heat exchanger and this, by means of the inlet pipes, to a final destination and this, by means of the outlet pipes, when said first and second fluids have passed through the heat exchanger.

State of the art

A heat exchanger, as described above, is disclosed in the German patent application DE 199 27 607. According to this document, the heat exchanger comprises a plurality of tubes obtained by means of stacked plates. one on the other inside a housing to obtain tubes for guiding a first fluid, from an inlet for this first fluid, to an outlet for this first fluid.

The different tubes define between them channels for guiding a second fluid, an inlet for this second fluid, to an outlet for this second fluid. The heat exchanger according to the German patent application DE 199 27 607 is adapted to guide the first fluid in the longitudinal direction of a housing, from a first end of the housing to a second end of the housing. The inlet and outlet for the second fluid are positioned in the side walls of the housing to allow entry and exit of said second fluid in a direction perpendicular to the flow direction of the first fluid.

The heat exchanger according to the German patent application DE 199 27 607 has a first disadvantage according to which the different fluid inlet and outlet connections are situated on four different walls of the casing forming the outside of the heat exchanger. . The inlet and the outlet intended for the first fluid are present on the ends of the casing, in the longitudinal direction of the casing. The inlet and outlet for the second fluid are present on the side walls of the housing. The arrangement of these fluid inlets and outlets limits the possibilities of adaptation to install the heat exchanger within an available space.

In addition, the manufacture of the heat exchanger according to the patent application DE 199 27 607 limits the heat exchange between the first and the second fluid, at a part of the length of said heat exchanger, that is to say say between the inlet and the outlet intended for the second fluid. In other words, a heat exchange between the first and the second fluid is impossible on part of the path of the first fluid. For this reason, a heat exchange with the device according to the German patent application DE 199 27 607 is not optimal with respect to the external dimensions of the heat exchanger. Nowadays, space for heat exchangers and their components within motor vehicles tends to be reduced in order to integrate other devices necessary for the operation of the motor vehicle. This means that the integration of a heat exchanger is more and more complex. For this reason, it is important to develop compact heat exchangers allowing a relative freedom of adaptation, in particular in the positioning of the inlet and outlet pipes of the first and second fluid, in order to to integrate, as efficiently as possible, the entire heat exchanger in the available space.

Object of the invention

The heat exchanger according to the present invention aims to overcome the disadvantages of heat exchangers known from the state of the art, by proposing a new design for the formation of an exchange beam to improve the compactness of said heat exchanger.

For this purpose, the invention relates to a heat exchanger for exchanging heat between a first and a second fluid, said exchanger comprising:

- a crankcase and

an exchange beam positioned inside said housing,

in which the exchange beam comprises:

a main surface comprising a main width and formed by a plurality of tubes adapted to guide the first fluid inside these tubes, an inlet of the first fluid to an outlet of the first fluid and for guiding, outside these tubes, the second fluid,

an inlet of the second fluid to an outlet of the second fluid,

in which the tubes are, at at least a first end, assembled to form a secondary surface comprising a secondary width smaller than the main width for connection to the inlet and / or outlet of the first fluid,

- In which the secondary surface at the first end of the tubes is formed to create a space between the housing and the outer face of the secondary surface, which space is connected to the inlet and / or outlet of the second fluid.

According to the invention, it is possible for the tubes to be, at a first end, assembled to form the secondary surface for connection to the inlet of the first fluid,

wherein the secondary surface at the first end of the tubes is formed to create a gap between the housing and the outer face of the secondary surface, which gap is connected to the outlet of the second fluid.

and wherein the tubes are, at the second end, assembled to form a secondary surface having a secondary width less than the width for connection to the outlet of the first fluid, said secondary surface at the second end of the tubes creating a space between the housing and the outer face of the secondary surface, which space is connected to the inlet of the second fluid.

Thus, initially, by forming and assembling the exchange beam according to the present invention, the inlets and outlets for the first and second fluid are located at opposite ends of the housing. This grouping of inputs and outputs increases the possibilities of adaptation and optimally integrates the entire heat exchanger into an available space.

Moreover, in a second step, the secondary surface makes it possible to connect the second end of the tubes to the outlet creating a space for the entry of the first fluid, has the advantage of being able to effect the heat exchange between the first and the second fluid throughout the flow of fluids, that is to say, their entry to their respective output. For this reason, the efficiency of the heat exchanger is increased with respect to its external dimensions.

According to one embodiment, the heat exchanger according to the present invention comprises a sealing element for wrapping the tubes at each end. According to one embodiment, the heat exchanger according to the present invention comprises a connecting element for connecting at least one end of the tubes to an inlet or an outlet with the aid of said connecting element.

According to one embodiment, the tubes are positioned relative to one another so as to create channels between them and in which said channels comprise disrupters. According to one embodiment of the present invention, the exchange beam is obtained by means of a plurality of plates positioned one on the other, the ends of said plates being provided with a rim making it possible to increase the surface area between the plate and inside the housing. Brief description of the drawings

The objects, objects and features of the present invention and its advantages will appear more clearly on reading the description which follows, of a preferred embodiment of a heat exchanger according to the invention, with reference to the drawings in FIG. which: FIG. 1 shows an exploded perspective view, a heat exchanger according to a first embodiment of the present invention, FIG. 2 shows the heat exchanger according to FIG. 1, in an assembled form,

FIG. 3 represents the exchange beam of the heat exchanger according to FIGS. 1 and 2,

FIG. 4 shows in detail two plates forming together a portion of the exchange beam according to FIG. 3;

FIG. 5 schematically shows a view of the main surface of the exchange beam, FIG. 6 schematically shows a view of the secondary surface of the exchange beam,

FIG. 7 represents an exploded perspective view of a heat exchanger according to a second embodiment of the present invention; FIG. 8 shows the exchange beam of the heat exchanger according to FIG. 7;

FIG. 9 represents in detail the end of the exchange beam according to FIG. 8,

Figure 10 shows an exploded perspective view of a third embodiment of the heat exchanger according to the present invention.

Detailed description of an embodiment

Figure 1 shows, in an exploded perspective view, a first embodiment of a heat exchanger 10 according to the present invention. The heat exchanger 10 comprises a first element 11 and a second element 12 allowing, in combination, to form the outside of the heat exchanger 10. The elements 11 and 12 combined form a housing or "housing" 11, 12 may contain elements for optimizing the heat exchange between a first and a second fluid. The second element 12 comprises the different inputs and outputs of the first and second fluid.

The inlet 21, present in the second element 12, constitutes the inlet intended for the first fluid. On the opposite face, the outlet 22 constitutes the outlet intended for the first fluid. The inlet 31 is intended for the second fluid. The output 32 is for the second fluid.

When using the heat exchanger 10, the first fluid enters through the inlet 21 inside said heat exchanger 10. Simultaneously, the second fluid enters the inside of the heat exchanger 10 via the inlet 31. Thus, the heat exchanger 10 comprises an exchange beam 13 comprising a stack of plates 17 forming, in combination, tubes and defined channels. between said tubes. The exchange beam 13 is shown in more detail in FIGS. 3 and 4. As indicated above, the exchange bundle 13 comprises a stack of plates 17 in which a set composed of two plates, forms in its interior a tube for guiding the first fluid from its inlet 21 to its outlet 22. Channels are defined between the different tubes and allow the second fluid to flow from its inlet 31 to its outlet 32.

For practical reasons and in order to facilitate references to the heat exchanger 10 as shown in FIG. 1, the dimensions "L", "1" and "h" are indicated in FIG. Is used to refer to the largest dimension of the heat exchanger 10 and corresponds to the direction in which the first and the second fluid flows. The letter "1" is used to indicate the width of the heat exchanger 10 and the letter "h" is used to indicate the height of the heat exchanger 10.

The stack of plates 17 makes it possible to obtain the exchange bundle 13 and is in the arrangement shown in FIG. 4. The plates 17 each have an internal face adapted to form the inner wall of a tube and adapted to be exposed to the first fluid, and an opposite or external face. This external face is in contact with the second fluid when using the plates 17.

Figure 4 shows that each plate 17 is provided in its longitudinal length with a curved element. This curved element is adapted to increase the contact area between the end of the plates 17 (seen in a longitudinal direction) and the inside of the walls of the first element 11 shown in FIG. 1. This surface increase facilitates the brazing process making it possible to assemble the different elements of the heat exchanger 10 against each other and to ensure an optimal contact in order to avoid any leakage of fluids during the use of the heat exchanger 10. In order to obtain the exchange bundle 13, the various plates 17 are positioned in such a way that the inner face of the first plate 17 is directed towards the inner face of the second plate 17, said second plate 17 being positioned with its outer face facing the inner face of the third plate 17, and so on according to the number of plates considered.

In the heat exchanger 10 according to FIG. 1, the various plates 17 have dimensions corresponding to the dimensions inside the casing 11, 12 of said heat exchanger 10. The width "1" of the plates 17, as shown in FIG. Figure 4, corresponds to the internal width of the housing 11, 12, as shown in Figure 1.

The shape of the tubes of the exchange bundle is modified at the ends of the tubes and has a narrowing. The exchange beam has at its ends a connection surface in which the outputs of the different tubes are assembled. As shown in FIG. 3, this connection surface is adapted to be connected by means of a connection element 14 to the outlet 32 intended for the second fluid. FIG. 1 depicts a sealing element 16 adapted to envelop the ends of the plates 17 forming together the exchange bundle 13. This sealing element 16 allows said plates 17 to be held together in order to avoid possible leaks from the inside of the tubes to the channels located outside the tubes and vice versa.

The connecting element 14 is adapted to connect the connection surface of the different tubes to the outlet 22. A connecting element 15 is provided on the opposite side of the exchange beam in order to connect the inlet 21 intended for the first fluid. at a connecting surface at the opposite end of said exchange beam 13. The operation of the heat exchanger according to the invention is based on the fact that the shapes of the plates 17 change between their first end 91 and their second end 92, as shown in FIG. 4. At the ends 91 and 92, the plates have a shape that makes it possible to compose, when combined, a tube of relatively short length "L" in order to allow the tubes to have a larger width. The surface of the section at the end of the tubes is indicated by the term "secondary surface". At the center 93 of the plates 17, the plates 17 are adapted to form a tube of a length "L" relatively large and a width "1" less important. Within the present invention, the cross-sectional area of the center of the tubes in a central area of the exchange bundle is indicated by the term "main surface". From the end 91 towards the central part, the plate 17 comprises a transformation zone. From the central portion 93 towards the end 92, each plate 17 includes a second transformation zone indicated by reference numeral 95.

The technical effect of the specific shapes of the plates 17 is shown, in a schematic version, in FIGS. 5 and 6.

FIG. 5 shows, in section, a portion of the exchange bundle 13. The inside of the tubes is indicated using the reference "A". The different tubes are separated by means of channels referenced "B". The inside of the tubes "A" is adapted to guide the first fluid and the channels "B" are adapted to guide the second fluid, against the current. FIG. 5 shows that at the center of the exchange beam 13, the different fluids are well separated and that heat exchange via the different walls is possible.

The exchange beam 13 is shown in FIG. 6, from the front and schematically. According to FIG. 6, thanks to the different transformation zones 94 and 95, the volume of the assembly formed by the tubes and the channels is specifically distributed at the ends of the plates 17. This volume distribution differs from the volume distribution. tubes and channels outside the ends of the exchange bundle. The different surfaces "A" form, at their ends, the secondary surface which, via a connection element 14, 15, can be connected to the inlet / outlet intended for the first fluid. The free space around the surface "A" allows the entry of the different channels "B" and can be connected to the inlet / outlet for the second fluid.

Thanks to the secondary surface of the tubes, the second fluid can enter the housing within the space surrounding the connecting element 14 and the narrowing of the tubes. The first fluid is then guided inside the "B" channels defined by the outside of the set of tubes "A" forming together the exchange bundle 13. The second fluid is guided between the different tubes in the direction of the space surrounding the narrowing and the connecting member 15 of the tubes towards the outlet 32.

FIG. 1 shows that the shape of the exchange bundle and the presence of a narrowing of the tubes at their ends, thanks to the transformation zones 94 and 95 of the plates 17, make available a free space inside the casing, formed by the elements 11 and 12, and outside this narrowing and the connecting element 14. This space created inside the housing allows the connection of the inlet 31 for the second fluid . The second fluid, directed via the inlet 31 in the direction of the exchange beam 13, can therefore flow outside the connecting element 14 and outside the narrowing of the tubes. In other words, this means that a heat exchange can occur between the first and the second fluid, through the walls of the connecting element 14 and directly after the introduction of the second fluid to the first fluid. Inside the heat exchanger 10. The same arrangement of the elements present at the opposite end of the exchange beam 13 allows an optimal heat exchange between the two fluids and this to the outlet 32 for the second fluid.

The various elements as shown in Figure 1 are assembled by a brazing process as known in the prior art. For the assembly of different elements within the heat exchanger 10, said elements are preassembled in a position identical to their position in the housing 11, 12 and introduced into a furnace. Aluminum and stainless steel are particularly suitable materials for forming the heat exchanger 10 according to the invention by the soldering method.

Figure 2 shows a perspective view of the heat exchanger 10 according to Figure 1 in an assembled position. Figure 2 shows that the heat exchanger 10 according to the invention is relatively compact. In addition, the various inputs and outputs 21 (not visible), 22, 31 and 32 are grouped to optimize the final installation of the heat exchanger 10 within a motor vehicle for example.

FIG. 3 shows in detail the exchange bundle 13. The plates 17 are stacked together to form, inside, tubes for guiding the first fluid, from a first end 131 to a second end 132 of the tubes and to define, between the different tubes, channels for guiding the second fluid. Disruptors 18 may be present between the different plates 17. Said disrupters 18 are intended to improve the heat exchange between the first and the second fluid during the use of the heat exchanger 10.

Figure 7 shows a second embodiment of the heat exchanger according to the invention. FIG. 7 shows a heat exchanger 40 whose structure is similar to that of the heat exchanger 10 according to FIG. 1 Only the plates forming the exchange beam 43 are positioned differently from those of the heat exchanger In fact, the plates are positioned vertically with respect to the length "L" of the heat exchanger 40.

The heat exchanger 40 comprises a first element 41 and a second element 42 constituting in combination a housing or housing 41, 42 to form the outside of said heat exchanger 40. The housing 41, 42 is adapted to contain a beam of exchange 43. This exchange beam 43 comprises a stack of plates 27 shown in Figures 8 and 9. The various plates 27, combined together, form tubes for guiding, in their interior, a first fluid from a first end to a second end of the exchange beam 43. The different tubes together define channels for guiding the second fluid outside the tubes, from the second end to the first end of the exchange beam 43. The ends of the different tubes have a narrowing in which said ends are grouped to form a connecting surface, said connecting surface being adapted to be connected, by means of a connection, to a respective inlet / outlet for the first fluid. The ends having a narrowing are clearly visible in Figures 8 and 9.

As shown in FIG. 7, an inlet 51 (partially visible) and an outlet 52, intended for the first fluid, are present in the second element 42. The inlet 51 is adapted to be connected to the connecting element 45 and for guiding the first fluid, from its inlet 51 to the inside of the tubes of the exchange bundle 43, with the aid of this element 45. The outlet 52 is adapted to be connected to the connection element 44 and to guide from the outlets of the different tubes and the connecting element 44, the first fluid towards its outlet 52.

Furthermore, the second element 42 comprises an inlet 61 and an outlet 62 (visible in part) for allowing a second fluid to enter the interior of the housing. Thanks to the narrowing present at the second end of the exchange beam 43, the second fluid can be guided outside the connecting element 44 and outside the ends of the tubes to continue its journey inside. channels defined by the different tubes. The second fluid can be guided towards the open space around the second end of the tubes and the outside of the connecting element 45 to exit the heat exchanger 40 by means of the outlet 62. The heat exchanger 40 comprises sealing elements 46 making it possible to hold the ends of the different tubes together and to improve the sealing of said tubes, thus avoiding possible leakage of fluids. FIG. 8 shows the connection of the ends of the tubes 66 to a first connecting element 44 and to a second connecting element 45.

FIG. 8 represents a detailed view of the exchange beam 43. The exchange beam comprises tubes 66, each formed by the stack of two plates comparable to the plates shown in FIG. 4. Disturbants 68 are visible between the different tubes 66, which disruptors facilitate the exchange between the first fluid inside the tubes 66 and the second fluid outside the tubes 66. The end of the different tubes 66 is shown in more detail in FIG. Figure 7 shows that the different ends of the tubes together form a secondary surface. This secondary surface is adapted for connection to the connecting element 44 as shown in FIG. 7. In order to improve the sealing, the different ends of the tubes 66 are wrapped with a sealing element 46. The FIG. 9 shows the secondary surface obtained by the connection of the different ends of the tubes.

The various elements of the heat exchanger 40 as shown in Figures 7, 8 and 9 can be assembled by a brazing process. In order to carry out this brazing process, different elements are assembled in their respective respective positions and introduced into an oven.

Figure 10 shows a heat exchanger according to a third embodiment 70 of the invention, shown in an exploded perspective view. As shown in Fig. 10, the heat exchanger 70 includes a first member 71 and a second member 72 together forming a housing. An exchange beam 73 is present inside said housing. The use of the heat exchanger heat 70 according to Figures 10 and 11 is similar to the use of the heat exchangers 10 and 40 as described above. A difference between the heat exchanger 70 and the heat exchangers 10 and 40 lies in the fact that the various tubes are, after their shrinkage and with their assembled surface, directly connected to an inlet / outlet present outside the housing. . This means that the connecting element for guiding the second fluid, according to Figures 10 and 11, is outside the housing.

Claims

A heat exchanger (10, 40, 70) for exchanging heat between a first and a second fluid, said exchanger (10, 40, 70) comprising:

a casing (11, 12; 41, 42; 71, 72) and

an exchange beam (13, 43, 73) positioned inside said casing (11, 12; 41, 42; 71, 72),

in which the exchange beam (13, 43, 73) comprises:

a main surface comprising a main width and formed by a plurality of tubes (66) adapted to guide the first fluid within said tubes (66),

an inlet of the first fluid (21, 51) to an outlet of the first fluid (22, 52) and for guiding, outside these tubes (66), the second fluid, an inlet of the second fluid (31, 61); ) to an outlet of the second fluid (33, 62),

in which the tubes (66) are, at at least a first end (131, 132), assembled to form a secondary surface having a secondary width smaller than the main width for connection to the inlet (21, 51) and / or the outlet (22, 52) of the first fluid,

in which the secondary surface at the first end (131, 132) of the tubes is formed to create a space between the housing (11, 12; 41, 42; 71, 72) and the outer surface of the secondary surface, which space is connected to the inlet (31, 61) and / or the outlet (32, 62) of the second fluid

The heat exchanger (10, 40, 70) according to claim 1 wherein the tubes (66) are, at a first end (131), assembled to form the secondary surface for connection to the inlet of the first fluid (21). , 51), in which the secondary surface at the first end (131) of the tubes (66) is formed to create a space between the housing (11, 12; 41, 42; 71, 72) and the outer face of the secondary surface, which space is connected to the outlet of the second fluid (32, 62);

and wherein the tubes (66) are, at the second end (132), assembled to form a secondary surface having a secondary width less than the width for connection to the outlet of the first fluid (22, 52), said secondary surface at the second end (132) of the tubes (66) creating a space between the housing (11, 12; 41, 42; 71, 72) and the outer face of the secondary surface, which space is connected to the inlet of the second fluid (31, 61).

Heat exchanger (10, 40, 70) according to claim 1 or 2, wherein said heat exchanger (10, 40, 70) comprises a sealing member (16, 46) for wrapping the tubes (66). at least one end (131, 132).

Heat exchanger according to claim 1, 2 or 3, wherein the heat exchanger (10, 40, 70) comprises a connecting element (14, 15; 44, 45) for connecting at least one end (131, 132) of the tubes (66) at an inlet (21, 51) or an outlet (22, 52) by means of said connecting element (14, 15; 44, 45).

Heat exchanger (10, 40, 70) according to one of the preceding claims, wherein the tubes (66) are positioned relative to each other so as to create channels therebetween, said channels comprise disrupters (18, 68).

Heat exchanger (10, 40, 70) according to one of the preceding claims wherein the exchange beam (13, 43, 73) is obtained by means of a plurality of plates (17, 27) positioned one on the other and wherein the ends of said plates (91, 92) are provided with a rim for increasing the area between the plate (17, 27) and the interior of the housing (11, 12; 41, 42; 71, 72).