FR3043189B1 - HEAT EXCHANGER COMPRISING AN EXCHANGE BEAM, HOUSING ADAPTED TO ENVELOP THE SAME, AND A METHOD FOR ASSEMBLING SUCH A HEAT EXCHANGER - Google Patents

Abstract

The present invention relates to a heat exchanger (1) for exchanging heat between a first fluid and a second fluid, said heat exchanger (1) comprising an exchange beam (15) and a housing (11, 20) adapted for wrapping said exchange bundle (15), wherein the heat exchanger (1) is provided with an inlet (16) and an outlet (17) for the first fluid and an inlet (21) and an outlet (22) for the second fluid, characterized in that the housing (11, 20) consists of a substantially planar, or preferably flat, plate-like first portion (11) for forming a wall of said housing, and a second receptacle-shaped portion (20), said second portion (20) including a free edge (25) adapted to be connected with said first portion (11), and thereby forming said housing (11, 20).

Description

Field of the invention

The present invention relates to the field of heat exchangers, adapted to allow heat exchange between a first and a second fluid, in particular heat exchangers comprising an exchange bundle and a housing adapted to envelop the latter. In addition, the invention relates to a method for assembling such a heat exchanger.

State of the art

In an air conditioning system, for example an air conditioning system intended for a motor vehicle, a refrigerant or refrigerant - used to cool the passenger compartment of said motor vehicle - circulates inside a condenser during a cooling cycle . In order to allow condensation (and therefore cooling) of the refrigerant, a determined quantity of heat is subtracted from said refrigerant when the latter is in a gaseous state.

In the prior art, it is known to obtain the cooling of a refrigerant using a heat exchanger, said heat exchanger being adapted to allow a heat exchange between the refrigerant and a fluid, such as water, to cool said refrigerant.

Such a heat exchanger generally comprises two separate circuits, one intended for the refrigerant, the other intended for the fluid for cooling the refrigerant.

More specifically, the heat exchanger of the prior art comprises an exchange bundle comprising a stack of tubes. The refrigerant can circulate inside the tubes, from a first end to a second end of these tubes. The fluid used to cool the refrigerant circulates outside these tubes, more precisely between two adjacent tubes, against the flow of the refrigerant, namely from the second end to the first end of the tubes. In addition to a stack of tubes, this exchange bundle includes manifolds fixed to the ends of said stack; these manifolds being respectively connected to the inlet and the outlet for the refrigerant.

Still according to the prior art, the tubes include a wall of a determined thickness to withstand the high pressure to which the refrigerant circulating inside said tubes is subjected. The heat exchange between the refrigerant and the fluid is carried out through this wall.

The heat exchangers disclosed in the prior art generally include an exchange bundle wrapped in a housing. It is known to assemble the assembly consisting of the exchange bundle and the housing by brazing (namely by using a brazing process).

In the prior art, it is known to produce housings from a plastic material. For example, patent application FR-A-2965336 discloses an assembly composed of a two-phase heat exchanger and a bottle, in which at least part of the housing enveloping the exchange bundle comprises plastic. As described in this patent application, the part comprising plastic material is fixed in a metal part comprising a groove for crimping the plastic housing.

However, the heat exchangers of the prior art, comprising an exchange bundle wrapped in a housing at least partially made of plastic, even if they function relatively satisfactorily, require improvements, in particular in order to increasing the efficiency of said heat exchanger.

Furthermore, in these heat exchangers of the prior art, the shape of the housing comprising at least one plastic part is dictated by the shape of all or part of the connection elements of the exchange bundle, making it possible to connect the housing together and the exchange beam. Thus, a given type of exchange harness corresponds to a particular type of housing. This results in the multiplication of production chains, in order to produce the different types of boxes corresponding to the different types of exchange bundles.

Object of the invention

An objective of the present invention therefore aims to increase the efficiency of heat exchangers of the prior art, comprising an exchange bundle wrapped in a housing made at least partly of plastic.

Another objective of the present invention is to develop a heat exchanger in which the connection between the part of the plastic casing and all or part of the connection elements of the exchange bundle makes it possible to avoid shape constraints for the housing of a heat exchanger. Other objectives will appear, if necessary, on reading this description.

Against all expectations, the Applicant has discovered that these objectives were achieved by a heat exchanger according to the invention.

Thus, the subject of the invention is a heat exchanger for exchanging heat between a first fluid and a second fluid, said heat exchanger comprising an exchange bundle and a housing suitable for enveloping said exchange bundle, in which the heat exchanger is provided with an inlet and an outlet intended for the first fluid and an inlet and an outlet intended for the second fluid, in which the housing consists of a first essentially flat part or, preferably planar (for example in the form of a plate), adapted to form a wall of said housing, and a second part in the form of a receptacle, said second part comprising a free edge adapted to be connected with said first part, and thus form said housing. According to a preferred embodiment of the invention, said free edge is adapted to be fixed to said first part, and thus form said housing.

An advantage of the heat exchanger according to the present invention lies in the fact that the housing of said heat exchanger comprises two parts. The first part is used as a support element ensuring the necessary feedback for crimping by the contacts of the free edge of the second part of the case having the shape of a receptacle. When the first part and the second part of the housing are thus connected, the free edge of the second part exerts pressure on the surface of the first part of said housing. A connection of this nature makes it possible to overcome the constraints of shapes on the housing, which is no longer necessarily limited to a simple rectangle, its shape being able to be optimized to correspond to a different type of exchange bundle.

According to one embodiment of the invention, the first part of the housing forms an integral part of the exchange bundle.

According to one embodiment of the invention, the first part of the housing and the exchange bundle are assembled by brazing.

According to an embodiment of the invention, the first part of the housing comprises a metallic material and the second part of the housing comprises a plastic material.

According to one embodiment of the invention, the first part is provided with fixing means for fixing the free edge of the second part of the housing to the first part of the housing.

According to one embodiment of the invention, preferably, the above fixing means comprise crimping teeth, adapted to fix the free edge of the second part of the housing on the first part of the housing.

According to a preferred embodiment of the invention of the invention, the free edge has a flange and the crimping teeth are adapted to fix said flange on the first part of the housing.

A collar extends from a folded edge or from an object in the shape of a crown or ring, allowing it to be assembled with another part, in this case with the first part of the case.

According to one embodiment of the invention, the free edge of the first part comprises a groove adapted to receive a sealing element such as a seal.

According to one embodiment of the invention, the inlet and outlet intended for the first fluid are arranged on the first part of the housing and the inlet and outlet intended for the second fluid are arranged on the second part of the housing.

According to one embodiment of the invention, the exchange bundle comprises a stack of tubes and manifolds at the ends of said stack, respectively connected to the inlet and the outlet intended for the first fluid.

Another object of the invention relates to a method for assembling a heat exchanger comprising the following steps: a) assembling by brazing the assembly formed by the exchange bundle and the first part of the housing, and b) connecting the free edge of the second part of the housing and the first part of the housing.

Preferably, step b) of connection of the free edge comprises: - fixing the free edge of the second part of the housing to the first part of the housing by means of crimping teeth.

According to a particular embodiment, step b) of connection of the free edge (25) comprises: - fixing the free edge of the second part of the housing on the first part via a sealing element.

According to one embodiment of the invention, step b) of connection of the free edge comprises: receiving inside a groove in the free edge of the second part of the housing a sealing element and fixing said edge free on the first part of said housing.

Brief description of the drawings

The aims, objects and characteristics of the present invention, as well as its advantages, will appear more clearly on reading the present description of the preferred embodiments of a heat exchanger according to the invention, made with reference to the drawings, in which : Figure 1 shows a perspective view of a heat exchanger according to the present invention, Figure 2 is an exploded view of the heat exchanger shown in Figure 1, Figure 3 shows a bottom view of three -quarts, of the second part of the housing of the heat exchanger according to the invention, and Figure 4 is a sectional view of a heat exchanger according to the present invention in which are shown in particular a manifold and one of the ends of the exchange bundle of the heat exchanger according to the present invention.

detailed description

The purpose of the description below is to set out the invention in a sufficiently clear and complete manner, in particular with reference to FIGS. 1-4, but should in no case be considered as limiting the scope of protection to the modes of realization described below.

As previously indicated, Figure 1 shows a perspective view of a heat exchanger 1 according to the invention. The different elements of the heat exchanger 1 are visible in FIG. 2. The heat exchanger 1 comprises a housing consisting of a first part 11 in the form of a plate, adapted to form one of the walls of the housing 11, 20, and a second part 20 in the form of a receptacle. This second part 20 in the form of a receptacle comprises a free edge 25, adapted to be fixed on the flat surface of the first part 11, and thus form a housing 11, 20. This housing 11, 20 represents, in a way, the wall or outer casing of the heat exchanger 1 according to the present invention.

As shown in Figure 1, the heat exchanger 1 is adapted to receive within it an exchange beam 15. The exchange beam 15 consists of a stack of tubes 12 and manifolds 13, 14 fixed at the ends of said stack 12. The manifold 13 is connected to the inlet 16 intended for a first fluid such as a refrigerant adapted to allow heat exchange inside the heat exchanger 1. The manifold 14 , meanwhile, is connected to outlet 17, also intended for said first fluid. The arrangement constituted by the stack of tubes 12 and manifolds 13, 14 is known from the prior art and is therefore not described here in detail. The manifolds 13, 14 are obtained by the assembly of four separate parts. These parts include an extruded comb-shaped box, a thin collector made of plated material and two end plugs, one of which is drilled to ensure the passage of the first fluid towards the flange.

The elements forming the exchange bundle 15 comprise a metallic material. This metallic material is selected to allow fixing of the stack of tubes 12 and manifolds 13, 14, fixed to the ends of said stack 12, by means of a brazing process.

According to the present invention, the wall formed by the first part 11 comprises a metallic material. Thus, the assembly constituted by the exchange bundle 15, the first part 11 adapted to form a wall of the housing 11, 20, the inlet 16 and the outlet 17 can easily be assembled during a brazing process, process well known to those skilled in the art.

In the embodiment shown in Figure 2, the second part 20 of the housing 11,20, essentially has the form of a receptacle comprising five walls and a free edge 25. This free edge 25 is adapted to be connected with the wall 11 , for example to be fixed on this wall 11. The second part 20 of the housing 11, 20, is provided with an inlet 21 intended for a second fluid such as water. The second part 20 of the housing 11,20 is also provided with an outlet 22 intended for said second fluid. The respective positioning of the inlet 16 and the outlet 17, intended for the first fluid, and of the inlet 21 and the outlet 22, intended for the second fluid, allows a heat exchange between the first fluid and the second fluid, the latter flowing against the current of the first fluid.

To ensure optimal operation of the heat exchanger 1, it is essential that the free edge 25 is correctly connected to (or fixed to) on the first part 11. As shown in FIG. 2, the free edge 25 is adapted to be fixed on the first part 11 using crimping teeth 18. The result of the fixing obtained by the cooperation of the free edge 25 and the crimping teeth 18 is visible in FIG. 4. Alternatively, the free edge 25 can be fixed on the first part 11 using any suitable fixing material such as glue. It also proves possible to improve the fixing of the free edge 25 on the first part 11 by combining a suitable fixing material, for example glue, and crimping teeth 18.

According to an embodiment of the invention (as shown in Figure 3), a sealing element 30 is positioned between the free edge 25 and the wall 11 (visible in Figure 2), thus improving the seal between said free edge 25 and said wall 11 (visible in FIG. 2).

FIG. 2 illustrates a particularly advantageous characteristic of the heat exchanger 1 according to the invention, namely that it makes it possible to overcome the form constraints at the level of the housing 11, 20. More precisely, as illustrated in FIG. 2, the second part 20 of the housing 11, 20, can be determined so as to follow the shape imposed by the exchange beam 15. Thus, the internal walls of the second part 20 of the housing 11, 20, are adapted to be in the immediate vicinity or, preferably in contact, with the outside of the exchange bundle 15. When the internal walls of the second part 20 of the housing 11,20, are adapted to be in contact with the outside of the bundle of exchange 15, the contact between the internal walls and the stack of tubes 12 is made locally on ribs 24 with very low clearance relative to the walls of the second part 20 of the housing 11, 20. This makes it possible to limit the path of the second fluid between the internal walls of the second part 20 of the housing 11, 20 and the outside of the exchange bundle 15, by forcing the circulation of the second fluid inside said exchange bundle 15.

As shown in FIG. 2, the inlet 21 and the outlet 22, both intended for the second fluid, are positioned at the level of the recesses where the manifolds 13, 14 are housed. Thus, the performance of the heat exchanger 1 , that is to say the heat exchanges between the first and the second fluid, are optimized thanks to the fact that a large part of the exchange surface - or even the entire exchange surface - is immersed in the second fluid.

The ribs 23 present on the outside of the walls of the second part 20 of the housing 11, 20, meanwhile, make it possible to increase the rigidity of said second part 20.

The free edge 25 of the second part 20 of the housing 11, 20 is clearly visible in FIG. 3. This free edge 25 is provided with a flange 26, particularly suitable for allowing the connection of the free edge 25 to the first part 11 of the case 11.20. The collar 26 can thus cooperate with the crimping teeth 18 of the first part 11 in order to guarantee a tight connection of the free edge 25 to the first part 11 of the housing 11,20.

As shown in FIG. 3, a sealing element 30 (such as a seal) is present, said sealing element 30 being able to be interposed between the free edge 25 and the first part 11 of the housing 11, 20, thereby improving seals the contact between the free edge 25 and the first part 11 of the housing 11, 20. The free edge 25, provided with a groove 27 making it possible to at least partially wrap the sealing element 30, thus receives said sealing element 30. The sealing element 30 is made, for example, using a flexible material such as rubber.

As shown, Figure 4 shows a sectional view of the part of the heat exchanger 1 including the manifold. In FIG. 4, we observe the inlet 21 intended for the second fluid such as water and allowing said second fluid to circulate between the adjacent tubes. In this figure 4 is also visible the outlet 17 intended for the first fluid (coolant), which outlet 17 is connected to the tubes via the manifold 14, and allowing the first and second fluids to circulate inside separate circuits. The fixing of the free edge 25 on the first part 11 using the crimping teeth 18. The crimping teeth 18 are fixed on the flange 26.

In FIG. 4, it is shown that the free edge 25 is provided with a groove 27. This groove 27 is adapted to receive at least part of a sealing element 30. During the fixing of the free edge 25 to the first part 11, the presence of such a sealing element 30 can improve the tightness of the connection between the first part 11 and the second part 20 of the housing 11,20. The heat exchanger 1 according to the invention is obtained using a method for assembling the heat exchanger 1 in which, in a first step, the assembly formed by the exchange bundle 15, the first part 11, the inlet 16 and the outlet 17 are assembled by brazing, the different elements all being made of metallic material.

Once the assembly of the exchange bundle 15 and of the first part 11 has been obtained, the heat exchanger 1 is obtained by connecting the free edge 25 of the second part 20 of the housing 11.20 to the first part 11 of the housing 11.20.

As regards obtaining the second part 20 of the housing 11, 20, this is preferably obtained by means of a molding process, such as an injection molding process. Said second part 20 of the housing 11, 20, being produced using plastic material, this provides optimum freedom as to the shape of said part 20. For example, the positioning of the inlet 21 and the outlet 22 of the second part 20 of the housing 11, 20, can be easily optimized in particular in order to take into account the location of the heat exchanger 1 within a motor vehicle, as well as the desired end uses of this exchanger heat 1. In a particularly advantageous manner, without having to modify either the shape or the operation of the exchange bundle 15, the positioning of the inlet 21 and of the outlet 22 within the second part 20 of the housing 11, 20, can be optimized in order to improve the contact with an inlet and an outlet intended for the second fluid.

In addition, in a particularly advantageous manner, the planar shape of the first part 11 of the housing 11,20 (in the form of a plate) makes it possible to obtain an internal volume of the housing 11, 20 greater than that offered by the housings of the prior art, this larger internal volume being available for the exchange bundle 15, while retaining an external volume and, consequently, a space identical to those of the housings of the prior art. In other words, for the same overall size, the invention makes it possible to increase the heat exchange surface compared to the devices of the prior art by adding, for example, additional tubes in the stack of tubes. 12 forming the exchange bundle 15 and, consequently, increasing the capacity of the heat exchanger to dissipate heat.

Claims (14)

claims 1. Heat exchanger (1) for exchanging heat between a first fluid and a second fluid, said heat exchanger (1) comprising an exchange bundle (15) and a housing (11, 20) suitable for enveloping said exchange bundle (15), in which the heat exchanger (1) is provided with an inlet (16) and an outlet (17) intended for the first fluid and with an inlet (21) and an outlet (22) intended for the second fluid, characterized in that, the housing (11, 20) consists of a first part (11) essentially planar or, preferably, planar, adapted to form a wall of said case, and a second part (20) in the form of a receptacle, said second part (20) comprising a free edge (25) adapted to be connected with said first part (11), and thus form said housing (11,20). 2. Heat exchanger (1) according to claim 1, wherein the first part (11) of the housing (11, 20) is an integral part of the exchange bundle (15). 3. Heat exchanger (1) according to claim 2, wherein the first part (11) of the housing (11, 20) and the exchange bundle (15) are assembled by brazing. 4. Heat exchanger (1) according to one of the preceding claims, wherein the first part (11) of the housing (11, 20) comprises a metallic material and wherein the second part (20) of the housing (11, 20 ) includes a plastic material. 5. Heat exchanger (1) according to one of the preceding claims, in which the first part (11) is provided with fixing means (18) for fixing the free edge (25) of the second part (20) of the housing. (11, 20) on the first part (11) of the case. 6. Heat exchanger (1) according to claim 5, wherein the fixing means (18) comprise crimping teeth (18), adapted to fix the free edge (25) of the second part (20) of the housing ( 11.20) on the first part (11) of the housing 7. Heat exchanger (1) according to claim 6, wherein the free edge (25) has a flange (26) and wherein the crimping teeth (18) are adapted to fix said flange (26) on the first part (11) of the housing (11,20). 8. Heat exchanger (1) according to one of the preceding claims, in which the free edge (25) of the first part (11) comprises a groove (27) adapted to receive a sealing element (30) such that 'a joint. 9. Heat exchanger (1) according to one of the preceding claims, in which the inlet (16) and the outlet (17) intended for the first fluid are arranged on the first part (11) of the housing (11, 20) and in which the inlet (21) and the outlet (22) intended for the second fluid are arranged on the second part (20) of the housing (11,20). 10. Heat exchanger (1) according to claim 9, wherein the exchange bundle (15) comprises a stack of tubes (12) and manifolds (13, 14) at the ends of said stack (12), respectively connected at the inlet (16) and the outlet (17) intended for the first fluid. 11. Method for assembling a heat exchanger (1) according to one of claims 1 to 10 comprising the following steps: a) assembling by brazing the assembly formed by the exchange bundle (15) and the first part (11 ) of the housing (11,20), and b) connecting the free edge (25) of the second part (20) of the housing (11,20) and the first part (11) of the housing (11,20). 12. The method of claim 11, when it depends on claim 5 or 6, wherein step b) of connection of the free edge (25) comprises: - fixing the free edge (25) of the second part (20 ) of the housing (11, 20) on the first part (11) of the housing (11, 20) by means of crimping teeth (18). 13. The method of claim 11 or 12, wherein step b) of connection of the free edge (25) comprises: - fixing the free edge (25) of the second part (20) of the housing (11, 20) on the first part (11) via a sealing element (30). 14. The method of claim 13, wherein step b) of connection of the free edge (25) comprises: - receiving in a groove (27) in the free edge (25) of the second part (20) of the housing ( 11,20) a sealing element (30) and fix said free edge (25) on the first part (11) of said housing (11,20).