EP4018146B1 - Heat exchanger, in particular for a motor vehicle, and process for manufacturing such a heat exchanger - Google Patents

Description

The present invention relates to the field of heat exchangers, in particular for motor vehicles, and to methods of manufacturing such heat exchangers.

Nowadays, heat exchangers are used in a large number of motor vehicles. These heat exchangers can, for example, be used to cool engines or batteries, or to operate air conditioning systems. EP 2 420 791 discloses a heat exchanger comprising the features of the preamble of claim 1.

Heat exchangers generally comprise a heat exchange bundle consisting of a set of superimposed hollow elements in which a first heat transfer fluid, such as glycolated water or a refrigerant, is intended to flow. This heat exchange bundle has a plurality of fins arranged between these hollow elements. These fins are configured to increase the heat exchange surface between the first heat transfer fluid circulating inside the hollow elements and a second heat transfer fluid, such as air, circulating between these hollow elements. However, such heat exchangers have a large number of parts and can be complex to assemble, in particular due to the mounting of the fins. Such a heat exchanger is for example described in the document EP 2869015 .

On the other hand, finned heat exchangers generate a certain thermal resistance for the exchange between the first heat transfer fluid, such as the refrigerant, and the second heat transfer fluid, such as air. Indeed, the surface of the fins allowing the exchange surface to be increased is not in direct contact with the two fluids. The heat exchanges between these two fluids with the heat exchangers of the prior art can therefore be improved.

We know about the document US 3757856 , a heat exchanger in which the hollow elements of the heat exchange bundle have protuberances or cavities so as to improve the exchange surfaces between the two fluids circulating in this heat exchanger. However, the heat exchanges between the first and second fluids within the heat exchange bundle described in this document can be improved.

The object of the present invention is to propose a heat exchanger having improved heat exchange capacities compared to those known from the prior art and having good mechanical strength.

Another objective of the present invention, different from the previous objective, is to provide a heat exchanger whose number of parts constituting it is limited.

Another objective of the present invention, different from the previous objectives, is to provide a heat exchanger which is simple and quick to assemble.

Another object of the present invention, different from the previous objectives, is to provide a method of manufacturing a heat exchanger which is simple, fast and inexpensive.

In order to achieve, at least partially, at least one of the aforementioned objectives, the present invention relates to a heat exchanger, in particular for a motor vehicle, comprising the characteristics of claim 1.

The possibility for the first fluid to pass from one hollow element to another hollow element through the protuberances connecting these hollow elements, allows a good homogenization of the temperature of this first fluid and also an improvement heat exchanges between the first and second fluids. On the other hand, the presence of the protuberances allows a disturbance of the circulation of the second fluid through the heat exchange bundle. Thus, the heat exchanges between the first and second fluids are improved due to the protuberances connecting the hollow elements together and also allowing the circulation of the first fluid through certain hollow protuberances. In addition, the protuberances are configured to connect the hollow elements together, which also makes it possible to simplify the structure of the heat exchange bundle by making it possible in particular to limit the number of parts making up this heat exchange bundle.

The heat exchanger according to the present invention may further comprise one or more of the following features taken alone or in combination.

According to a first aspect, the hollow elements of the heat exchange bundle may be plates.

According to this first aspect, the heat exchange beam can be formed by a row of superimposed plates.

According to a second aspect, the hollow elements of the heat exchange bundle may be flat tubes.

According to this second aspect, the heat exchange bundle can be formed by at least one row of superimposed flat tubes.

Hollow elements may be made of a material having a thermal conductivity greater than or equal to 45 Wm ^-1 .K ^-1 at 20°C.

Hollow elements can be made of metal or a metal alloy, particularly aluminium.

According to a particular embodiment, the first hollow element can carry at least one hollow protuberance cooperating with an orifice made in the second hollow element arranged opposite the at least one hollow protuberance of the first hollow element, said hollow protuberance ensuring fluid communication between the first and second hollow elements and forming a sealed connection with the orifice.

According to this particular embodiment, the first and second hollow elements alternately have a hollow protuberance and an orifice intended to cooperate with a hollow protuberance in a sealed manner in the assembled state of the heat exchange bundle.

According to another particular embodiment, the first and second hollow elements may each have at least one hollow protuberance, the hollow protuberance carried by the first hollow element having an end cooperating with an end of the hollow protuberance carried by the second hollow element and forming a sealed connection with this hollow protuberance of the second hollow element so as to allow fluid communication between the first and second hollow elements.

According to one aspect, each channel for the circulation of the first fluid has a center and a periphery and the at least one hollow protuberance allowing fluid communication between two adjacent hollow elements can be arranged at the center of the channel.

In one aspect, the plurality of protrusions carried by the at least one hollow element may be hollow protrusions allowing fluid communication between the first and second hollow elements.

According to a first particular embodiment, the hollow protuberances may have a constant section shape, a first end of which is arranged in contact with a face of the hollow element carrying the protuberance and a second free end, arranged opposite the first end and in contact with the adjacent hollow element.

According to this first particular embodiment, the section of the hollow protuberance can be circular, oblong, or even parallelepipedal in shape.

According to a second particular embodiment, the hollow protuberances may have a variable section shape, a first end of which is arranged in contact with a face of the hollow element carrying the protuberance and a second free end, opposite the first end and arranged in contact with the adjacent hollow element, said first end having a section whose area is greater than that of the second free end.

According to this second particular embodiment, the hollow protuberance may be conical in shape, the second end of which is flat or dome-shaped.

According to a variant of this second particular embodiment, the hollow protuberances have a leading wall and an end wall, the leading wall being the first in contact with the first fluid during the passage of this first fluid at the level of the hollow protuberance.

According to a particular embodiment of this variant, the hollow elements each have at least one hollow protuberance whose second free ends are in contact with each other, and these hollow protuberances have a central symmetry relative to the center of the opening of the hollow protuberances for the passage of the first fluid between a first and a second hollow element.

According to this variant, the leading wall of the hollow protuberance and the channel of the hollow element can form an angle of between 90° and 180°, and in particular of between 105° and 150°.

According to this variant also, the end wall of the hollow protuberance and the channel of the hollow element can form an angle between 90° and 180°, and in particular between 120° and 165°.

Also according to this variant, the hollow element can have at least one transverse partition.

The transverse partition can be arranged in the middle of the space defined between two hollow protrusions in the hollow element.

According to a particular embodiment, the heat exchange bundle may further comprise two end elements arranged parallel to the superimposed hollow elements and respectively on either side of the superposition of hollow elements, each end element has a face arranged opposite a face of a hollow element and defining a space between the end element and the hollow element to allow the circulation of the second fluid.

The face of the end member may be smooth and is configured to obstruct openings of the second ends of the hollow protrusions disposed opposite the end member so as to form a sealed connection between the hollow member and the adjacent member.

• réalisation de protubérances creuses par emboutissage d'au moins une face d'un premier élément creux, au moins une partie des protubérances creuses présentant une ouverture disposée au niveau d'une deuxième extrémité opposée à une première extrémité disposée au contact du premier élément creux ;
• formation d'un empilement comprenant au moins un premier et un deuxième éléments creux superposés, la face du premier élément creux présentant les protubérances creuses étant disposée en regard d'une face du deuxième élément creux présentant des orifices et de manière à ce que les protubérances coopèrent avec les orifices ; et
• chauffe et compression de l'empilement afin de permettre la liaison mécanique par brasage au moins des protubérances creuses portées par le premier élément creux avec le pourtour des orifices portés par le deuxième élément creux afin de former une liaison mécanique étanche entre les premier et deuxième éléments creux.

The present invention also relates to a method of manufacturing a heat exchanger as defined above, comprising the following steps:

• production of hollow protuberances by stamping at least one face of a first hollow element, at least part of the hollow protuberances having an opening arranged at a second end opposite a first end arranged in contact with the first hollow element;
• forming a stack comprising at least a first and a second superimposed hollow element, the face of the first hollow element having the hollow protuberances being arranged opposite a face of the second hollow element having orifices and in such a way that the protuberances cooperate with the orifices; and
• heating and compressing the stack in order to allow the mechanical connection by brazing of at least the hollow protuberances carried by the first hollow element with the periphery of the orifices carried by the second hollow element in order to form a sealed mechanical connection between the first and second hollow elements.

According to a particular embodiment, the orifices of the second hollow element can correspond to the opening of the second end of the protuberances carried by the second hollow element.

According to a variant, the stack may further comprise two end elements arranged respectively on either side of the superposition of hollow elements and parallel to these hollow elements, said end elements having a face arranged opposite a face of the adjacent hollow element, said face of the end elements being smooth.

According to this variant, the hollow elements arranged opposite the end elements may have hollow protuberances on their face arranged opposite the end elements in order to allow the brazing of the end elements with the adjacent hollow elements and the formation of a sealed mechanical connection between the hollow elements and the end elements.

• [Fig. 1] la figure 1 est une représentation schématique en perspective d'un échangeur de chaleur ;
• [Fig. 2] la figure 2 est une représentation schématique en perspective partielle d'un faisceau d'échange thermique de l'échangeur de chaleur de la figure 1 ;
• [Fig. 3A] la figure 3A est une représentation schématique en perspective d'un ensemble de protubérances selon une première variante ;
• [Fig. 3B] la figure 3B est une représentation schématique en perspective d'un ensemble de protubérances selon une deuxième variante ;
• [Fig. 3C] la figure 3C est une représentation schématique en perspective d'un ensemble de protubérances selon une troisième variante ;
• [Fig. 4A] la figure 4A est une représentation schématique en perspective d'un ensemble de protubérances selon une quatrième variante ;
• [Fig. 4B] la figure 4B est une représentation schématique en perspective d'un ensemble de protubérances selon une cinquième variante;
• [Fig. 5A] la figure 5A est une représentation schématique en coupe transversale de deux protubérances coopérant entre elles selon un premier mode de réalisation;
• [Fig. 5B] la figure 5B est une représentation schématique en coupe transversale de deux protubérances coopérant entre elles selon un deuxième mode de réalisation ;
• [Fig. 6] la figure 6 est une représentation schématique en coupe transversale de deux éléments creux du faisceau d'échange thermique de la figure 2 en communication fluidique selon un premier mode de réalisation particulier ;
• [Fig. 7] la figure 7 est une représentation schématique en coupe transversale de deux éléments creux du faisceau d'échange thermique de la figure 2 en communication fluidique selon un deuxième mode de réalisation particulier ;
• [Fig. 8] la figure 8 est une représentation schématique en coupe transversale de deux éléments creux du faisceau d'échange thermique de la figure 2 en communication fluidique selon un troisième mode de réalisation particulier ;
• [Fig. 9] la figure 9 est une représentation schématique en coupe transversale de deux éléments creux du faisceau d'échange thermique de la figure 2 en communication fluidique selon un quatrième mode de réalisation particulier ;
• [Fig. 10] la figure 10 est une représentation schématique en coupe transversale d'un faisceau d'échange thermique présentant des éléments creux en communication fluidique selon un cinquième mode de réalisation particulier ; et
• [Fig. 11] la figure 11 est une représentation schématique d'un organigramme illustrant un procédé de fabrication de l'échangeur de chaleur de la figure 1.

Other features and advantages of the present invention will appear more clearly on reading the following description, given for illustrative and non-limiting purposes, and the appended drawings in which:

• [ Fig. 1 ] there figure 1 is a schematic perspective representation of a heat exchanger;
• [ Fig. 2 ] there figure 2 is a partial perspective schematic representation of a heat exchange bundle of the heat exchanger of the figure 1 ;
• [ Fig. 3A ] there Figure 3A is a schematic perspective representation of a set of protuberances according to a first variant;
• [ Fig. 3B ] there Figure 3B is a schematic perspective representation of a set of protuberances according to a second variant;
• [ Fig. 3C ] there Figure 3C is a schematic perspective representation of a set of protuberances according to a third variant;
• [ Fig. 4A ] there Figure 4A is a schematic perspective representation of a set of protuberances according to a fourth variant;
• [ Fig. 4B ] there Figure 4B is a schematic perspective representation of a set of protuberances according to a fifth variant;
• [ Fig. 5A ] there Figure 5A is a schematic cross-sectional representation of two protuberances cooperating with each other according to a first embodiment;
• [ Fig. 5B ] there Figure 5B is a schematic cross-sectional representation of two protuberances cooperating with each other according to a second embodiment;
• [ Fig. 6 ] there figure 6 is a schematic cross-sectional representation of two hollow elements of the heat exchange bundle of the figure 2 in fluid communication according to a first particular embodiment;
• [ Fig. 7 ] there figure 7 is a schematic cross-sectional representation of two hollow elements of the heat exchange bundle of the figure 2 in fluid communication according to a second particular embodiment;
• [ Fig. 8 ] there figure 8 is a schematic cross-sectional representation of two hollow elements of the heat exchange bundle of the figure 2 in fluid communication according to a third particular embodiment;
• [ Fig. 9 ] there figure 9 is a schematic cross-sectional representation of two hollow elements of the heat exchange bundle of the figure 2 in fluid communication according to a fourth particular embodiment;
• [ Fig. 10 ] there figure 10 is a schematic cross-sectional representation of a heat exchange bundle having hollow elements in fluid communication according to a fifth particular embodiment; and
• [ Fig. 11 ] there figure 11 is a schematic representation of a flow chart illustrating a manufacturing process of the heat exchanger of the figure 1 .

Identical elements in different figures bear the same references.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments embodiments may also be combined and/or interchanged to provide other embodiments.

In the present description, certain elements or parameters may be indexed, such as for example first element or second element as well as first parameter and second parameter or even first criterion and second criterion etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria that are close but not identical. This indexing does not imply a priority of one element, parameter or criterion over another and such names can easily be interchanged without departing from the scope of the present description. This indexing also does not imply an order in time for example to assess such and such criteria.

In the following description, "thermal conductivity" means the energy, or quantity of heat, transferred per unit area and time, expressed in watts per meter-kelvin (Wm ^-1 .K ^-1 ).

Then, by "fluid" in the following description, we mean a body whose molecules have little adhesion and can slide freely relative to each other (in the case of liquids) or move independently of each other (in the case of gases), so that the body takes the shape of the vessel which contains it.

In reference to the figure 1 , a heat exchanger 1 is shown, in particular for a motor vehicle. This heat exchanger 1 comprises a heat exchange bundle 3 between at least a first heat transfer fluid F1 and a second heat transfer fluid F2 (visible in the figure 2 ). The heat exchange bundle 3 is composed of at least two superimposed hollow elements 31. Each hollow element 31 forms at least one channel 35 (visible on the figure 2 ) inside which the first fluid F1 is intended to circulate. The heat exchanger 1 further comprises a first 11 and a second 13 collector boxes. The first 11 and second 13 collector boxes are arranged at the ends of the hollow elements 31 and form with the heat exchange bundle 3 the heat exchanger 1. The first collector box 11 has for example an inlet 11a in order to supply the hollow elements 31 with first fluid F1 and the second collector box 13 has for example an outlet 13a in order to allow the circulation of the first fluid F1 in a circuit (not shown) allowing the return of this first fluid F1 to the level of the first collector box 11. This first heat transfer fluid F1 may in particular be a liquid, such as for example glycolated water or a refrigerant fluid. These first 11 and second 13 collector boxes are attached to the heat exchange bundle 3 in order to form the heat exchanger 1. These first 11 and second 13 collector boxes may be fixed to the heat exchange bundle 3 by brazing or by a mechanical connection, in particular by crimping, for example. The superimposed hollow elements 31 of the heat exchange bundle 3 may be plates in order to form a plate heat exchanger 1, or else be flat tubes in order to form a tube heat exchanger 1. The heat exchange bundle 3 may therefore be produced by a row of superimposed plates or else by at least one row of superimposed flat tubes. In the case where the heat exchange bundle 3 has more than one row of flat tubes, these rows are arranged side by side in the direction of circulation of the second fluid F2 (shown in the figure 2 ). The superimposed hollow elements 31 of the heat exchange bundle 3 may in particular be made of a material having a thermal conductivity greater than or equal to 45 Wm ^-1 .K ^-1 at 20°C. Typically, these hollow elements may be made of metal or a metal alloy, and in particular aluminum. Such thermal conductivity for the material constituting the hollow elements 31 makes it possible to ensure good heat transfers between the first F1 and the second F2 fluids in this heat exchange bundle 3 in order to allow in particular the heat exchanges of the first fluid F1.

In reference to the Figures 1 and 2 , the hollow elements 31 are also configured to allow the circulation of the second fluid F2 in a space 37 between the hollow elements 31 in order to allow a heat exchange between the first F1 and the second F2 fluids during the operation of this heat exchanger 1. The second heat transfer fluid F2 may for example be air intended to circulate between the hollow elements 31 in order to exchange thermal energy with the first fluid F1 circulating inside the hollow elements 31 for example.

Depending on the particular embodiment of the figure 2 , there is shown a hollow element 31 having two channels 35 each having a center and a periphery. According to other alternatives, the hollow element 31 may have a different number of channels 35.

In reference to the Figures 1 and 2 , at least one of the hollow elements 31 of the heat exchange bundle 3 has a plurality of protuberances 5. The protuberances 5 extend into the space 37 defined for the circulation of the second fluid F2. Such an arrangement of the protuberances 5 in the space 37 defined for the passage of the second fluid F2 makes it possible to create disturbances in the flow of the second fluid F2 through the heat exchange bundle 3, which allows, among other things, better homogenization of the temperature of this second fluid F2 and an improvement in the heat exchanges between the first F1 and the second F2 fluids circulating in the heat exchange bundle 3. This disturbance of the flow of the second fluid F2 in the space 37 may in particular consist of a reduction in its speed or even a disturbance in its direction of circulation allowing better homogenization of its temperature. Furthermore, the protuberances 5 form the connection between two adjacent hollow elements 31. Here, adjacent elements are understood to mean two elements arranged opposite one another. In addition, at least one first hollow element 31a and one second hollow element 31b arranged opposite one another are in fluid communication with one another by at least one hollow protuberance 5 carried by at least one of the first 31a and/or second 31b hollow elements 31.

Depending on the particular embodiment of the figure 1 , the heat exchange bundle 3 may further comprise two end elements 38, 39 arranged parallel to the superimposed hollow elements 31 and respectively on either side of the superposition of hollow elements 31. Each end element 38, 39 has a face arranged opposite a face of a hollow element 31 and defines a space 37' between the end element 38, 39 and the hollow element 31 to allow the circulation of the second fluid F2. These end elements 38, 39 may be made of a plate, for example made of metal or a metal alloy such as, for example, aluminum or an aluminum alloy. According to a particular embodiment, the material constituting the end elements 38, 39 is identical to that forming the hollow elements 31.

Depending on the particular embodiment of the figure 2 , the protuberances 5 are formed directly on the faces of the hollow elements 31. According to this particular embodiment, the protuberances 5 can be produced by deformation of a surface of the hollow elements 31.

In reference to the Figures 2 to 5B , the protuberances 5 have a first end 51 arranged in contact with the face of the hollow element 31 which carries the protuberance 5 and a second free end 53, opposite the first end 51, intended to be in contact with the hollow element 31 or the adjacent end element 38, 39 (visible in the figure 1 ). Here, the term adjacent element is understood to mean an element of the heat exchange bundle 3 arranged opposite a face of a hollow element 31. An adjacent element can therefore be another hollow element 31, or even an end element 38, 39. The second free end 53 of the hollow protuberances 5 has an opening configured to ensure fluid communication between the first 31a and the second 31b hollow elements.

In reference to the Figures 3A to 3C , the hollow protuberances 5 are shown according to a first variant. According to this first variant, the hollow protuberances 5 may have a constant section shape. By constant section shape, it is understood here that the hollow protuberance 5 has a constant diameter over its entire length, that is to say over the entire space 37, 37' arranged between the elements 31, 38, 39 for the passage of the second fluid F2 in which it extends. According to the different embodiments shown with reference to Figures 3A to 3C , two hollow protuberances 5 are shown, the second free ends 53 of which have an opening for the passage of the first fluid F1 and are arranged respectively in contact with each other and form a sealed connection. Such an arrangement of the hollow protuberances 5 corresponds to that described previously with reference to the second particular embodiment and can offer significant resistance to deformations related to the passage of the second fluid F2 in the space 37, 37'. More particularly according to this first variant, the section of the hollow protuberance 5 can be oblong in shape ( Figure 3A ), parallelepiped ( Figure 3B ), or even circular ( Figure 3C ).

In reference to the Figures 4A and 4B , the hollow protuberances 5 are shown according to a second variant. According to this second variant, the hollow protuberances 5 may have a variable section shape. By variable section shape, it is meant here that the hollow protuberance 5 has a variable diameter over its entire length, that is to say over the entire space 37, 37' arranged between the elements 31, 38, 39 for the passage of the second fluid F2 in which it extends. The first end 51 of the hollow protuberances 5 has an area greater than that of the second free end 53. According to the different embodiments shown with reference to the Figures 4A and 4B , two hollow protuberances 5 are shown, the second free ends 53 of which having an opening for the passage of the first fluid F1 are arranged respectively in contact with each other. Thus, such an arrangement of the hollow protuberances 5 also corresponds to the second particular embodiment described above. Such hollow protuberances 5 can make it possible to limit the reduction in the flow rate of the second fluid F2 in the space 37, 37' defined between a hollow element 31 and an adjacent element 31, 38, 39 while disturbing the circulation of this second fluid F2 in the space 37, 37' and the circulation of the first fluid F1 inside the hollow elements 31. More particularly according to this second variant, the hollow protuberances 5 can have a conical shape having a second free end 53 that is flat ( Figure 4A ), or even a dome shape ( Figure 4B ).

In reference to the Figures 3A to 4B , the shape of the hollow protuberances 5 can be chosen according to the constraints that they may be subjected to during the operation of the heat exchanger 1 or during the brazing of the heat exchange bundle 3. The shape of these hollow protuberances 5 can also be chosen according to the disturbances in the flow of the second fluid F2 and/or the first fluid F1 (visible on the figure 2 ) desired in space 37, 37' (visible in particular on the figure 1 ).

Furthermore, with reference to the Figures 5A And 5B , there is shown a sectional view of two protuberances 5 cooperating with each other at their second free end 53 in order to allow them to be joined by brazing to form a mechanical connection between the first 31a and second 31b hollow elements having these protuberances 5 arranged opposite each other. According to the particular embodiment of the Figure 5A , the protuberances 5 have a contact zone 54 at the level of the periphery of their second free ends 53. This contact zone 54 makes it possible to ensure brazing between these second free ends 53 to allow the formation of the heat exchange bundle 3 (notably visible on the figure 3 ). According to a particular embodiment, this contact zone 54 may have a length greater than or equal to 0.5 mm. This particular embodiment is described here for two protuberances 5 cooperating with each other. However, according to a variant not shown here, the contact zone 54 of the second free end 53 of a protuberance 5 may cooperate with the periphery of a orifice carried by the face of a hollow element 31 arranged opposite this protuberance 5. On the other hand, according to the particular embodiment of the Figure 5B , the second free ends 53 of the protuberances 5 carried respectively by a first 31a and a second 31b hollow elements and arranged opposite each other can be nested in order to allow the brazing of these second free ends 53 and thus the formation of the mechanical connection to form the heat exchange bundle 3.

The assembly of the heat exchange bundle 3 by brazing makes it possible to ensure good mechanical maintenance of this heat exchange bundle 3. Furthermore, the protuberances 5 occupy the space 37, 37' for the passage of the second fluid F2. In the case of heat exchangers of the prior art, this space was occupied by the presence of fins arranged between the hollow elements 31. The presence of the protuberances 5 therefore makes it possible to limit the number of components of the heat exchange bundle 3, which in particular makes it possible to simplify its structure and assembly by eliminating the presence of the fins known from the prior art. Such a heat exchange bundle 3 therefore has fairly low production costs while guaranteeing good mechanical strength thereof. Alternatively or in addition, such a mechanical connection of the heat exchange bundle 3 is also achievable when the latter has the end elements 38, 39, one face of which is arranged opposite the second free ends 53 of the protuberances 5, possibly hollow, and thus defining the space 37' for the passage of the second fluid F2. On the other hand, this face of the end elements 38, 39 is smooth and configured to obstruct the openings of the second free ends 53 of the hollow protuberances 5 arranged opposite the end element 38, 39 so as to form a sealed connection between the hollow element 31 and the adjacent element 31, 38, 39.

According to a first particular embodiment shown with reference to the figure 6 , a first hollow element 31a can carry at least one hollow protuberance 5 cooperating with an orifice 36 made in a second hollow element 31b arranged opposite this hollow protuberance 5 of the first hollow element 31a. The second free end 53 of this hollow protuberance 5 ensures the fluid communication between the first 31a and second 31b hollow elements for the first fluid F1 and forms a sealed connection with the orifice carried by the second hollow element 31b. According to the particular embodiment of the figure 6 , the first hollow element 31a has the hollow protuberances 5 and the second hollow element 31b has the orifices in order to allow fluid communication between these first 31a and second 31b hollow elements and also the formation of the sealed mechanical connection between these hollow elements 31a, 31b.

According to a variant of this first particular embodiment not shown here, the first 31a and second 31b hollow elements may alternately have a hollow protuberance 5 and an orifice 36. This orifice 36 is intended to cooperate with the second free end 53 of a hollow protuberance 5 carried by the face of the hollow element 31 arranged opposite this orifice 36. Furthermore, the connection between the hollow protuberance 5 and the orifice 36 is a sealed mechanical connection, which may in particular be produced by brazing.

According to a second particular embodiment shown with reference to the figure 7 , the first 31a and the second 31b hollow elements each have at least one protuberance 5, the second free end 53 of the hollow protuberance 5 carried by the first hollow element 31a cooperating with the second free end 53 of the hollow protuberance 5 carried by the second hollow element 31b. These second free ends 53 of the hollow protuberances 5 carried by the first 31a and second 31b hollow elements form a sealed connection so as to allow fluid communication between the first 31a and second 31b hollow elements.

According to these first and second embodiments, the first fluid F1 has turbulence T at the first ends 51 of the hollow protuberances 5. This turbulence T linked to the passage of the first fluid F1 at least at the first ends 51 of the protuberances 5 allows a disturbance of the flow of this first fluid F1 in the hollow element 31, thus contributing to an improvement in the homogenization of the temperature of this first fluid F1 and therefore of the heat exchanges between the first F1 and the second F2 fluids. On the other hand, the first fluid F1 can pass from the first hollow element 31a to the second hollow element 31b and vice versa by passing through one of the protuberances 5. Furthermore, according to these first and second particular embodiments, the plurality of protuberances 5 carried by the at least one hollow element 31 are hollow protuberances 5 allowing fluid communication between the first 31a and the second 31b hollow elements.

Thus, these hollow protuberances 5 ensuring fluid communication between the first 31a and second 31b hollow elements allow the first fluid F1 to pass from the first hollow element 31a to the second hollow element 31b and reverse. Such a movement of the first fluid F1 allows agitation of the latter at least at the level of the hollow protuberance 5, thus contributing to an improvement in the homogenization of its temperature. In addition, such a disturbance of the flow of the first fluid F1 allows an improvement in its heat exchanges with the second fluid F2 circulating in the space 37 between two adjacent hollow elements 31.

On the other hand, according to a third particular embodiment shown with reference to the figure 8 , the hollow elements 31 may comprise transverse partitions 9. The transverse partitions 9 obstruct a section of the channel 35 so that the first fluid F1 circulates between two adjacent hollow elements 31 in fluid communication. These transverse partitions 9 therefore allow the formation of a baffle for the first fluid F1. This baffle imposes the circulation of the first fluid F1 between the first hollow element 31a and the second hollow element 31b and vice versa. According to the particular embodiment of the figure 8 , the hollow elements 31 have transverse partitions 9 arranged in a staggered manner and between each hollow protuberance 5 in order to maximize the passages of the first fluid F1 between the first 31a and second 31b hollow elements in order to have good homogenization of its temperature and thus improve the heat exchanges that this first fluid F1 can have with the second fluid F2 within the heat exchange bundle 3. According to an alternative not shown here, the hollow elements 31 may have a lower number of transverse partitions 9 and more particularly more spaced from each other within the same hollow element 31.

In reference to the figure 9 , a fourth embodiment of the hollow protuberances 5 is shown. This fourth embodiment makes it possible in particular to limit the pressure losses linked to the passage of the first fluid F1 between the first 31a and second 31b hollow elements. According to this fourth embodiment, the first 31a and second 31b hollow elements each have hollow protuberances 5 arranged opposite each other. Furthermore, these hollow protuberances 5 have a variable section. More particularly, the hollow protuberances 5 have a leading wall 55 and an end wall 57. According to this fourth particular embodiment, the leading wall 55 of the hollow protuberance 5 is the first encountered in the direction of circulation of the first fluid F1. According to this fourth particular embodiment, the leading wall 55 of the hollow protuberance 5 and the channel 35 of the hollow element 31 form an angle α between 0° (limit excluded) and 90° (limit excluded), and in particular between 15° and 60°. On the other hand, the end wall 57 of the hollow protuberance 5 and the channel 35 of the hollow element 31 form an angle β between 90° and 180° (limit excluded), and in particular between 105° and 150°. According to the particular embodiment of the figure 9 , each of the first 31a and second 31b hollow elements has hollow protuberances 5 whose second free ends 53 are arranged facing each other in order to ensure the mechanical connection, in particular by brazing, of these first 31a and second 31b hollow elements. According to this particular embodiment, these second free ends 53 have an opening in order to allow the passage of the first fluid F1 from the first hollow element 31a to the second hollow element 31b and vice versa. Furthermore, these hollow protuberances 5 facing each other have a central symmetry relative to the center of the opening for the circulation of the first fluid F1 between these first 31a and second 31b hollow elements.

On the other hand, depending on the particular embodiment of the figure 9 , the hollow elements 31 also have transverse partitions 9 connecting the walls 35a of the channel 35 to each other. According to this particular embodiment, these transverse partitions are arranged in a staggered manner in the first 31a and second 31b hollow elements and separate the hollow protuberances 5 from each other. Furthermore, and still according to this particular embodiment, the transverse partitions 9 are arranged in the center of the length separating two hollow protuberances 5. According to other alternatives not shown here, the transverse partitions 9 may have a different spacing or even a different positioning within the first 31a and second 31b hollow elements.

According to a particular embodiment not shown here, each channel 35 for the circulation of the first fluid F1 has a center and a periphery and the at least one hollow protuberance 5 allowing fluid communication between two adjacent hollow elements 31 is arranged at the center of this channel 35.

On the other hand, according to a fifth particular embodiment shown with reference to the figure 10 , the heat exchange bundle 3 has more than two hollow elements 31, and more particularly a first 31a, a second 31b, and a third 31c hollow elements, all in fluid communication via the protuberances 5. According to this fifth particular embodiment, the different hollow elements 31a, 31b, 31c have transverse partitions 9 configured to direct the flow towards a channel 35 of a particular hollow element 31. More particularly according to this fifth particular embodiment, the transverse partitions 9 are arranged so as to define flow directions for the first fluid F1 in directions orthogonal to the channels 35 of the hollow elements 31. Such an arrangement of the transverse partitions 9 increases the path traveled by the first fluid F1 in the heat exchange bundle 3, which contributes to improving the heat exchanges between the first F1 and second F2 fluids. Furthermore, such a configuration of the heat exchange bundle 3 also makes it possible to limit the pressure losses linked to the different changes of direction of the first fluid F1.

In reference to the figure 11 , there is shown a manufacturing method 100 of a heat exchanger 1 as described above. The manufacturing method 100 comprises a step E1 of producing hollow protuberances 5 on at least one face of a hollow element 31. At least a portion of these hollow protuberances 5 has an opening arranged at their second free end 53 opposite their first end 51 arranged in contact with the first hollow element 31a. These hollow protuberances 5 can in particular be produced by stamping the at least one face of this hollow element 31.

The manufacturing method 100 then implements a step of preparing a stack E2. This stack comprises at least a first 31a and a second 31b superimposed hollow elements. In addition, the face of the first hollow element 31a having the hollow protuberances 5 is arranged opposite the face of the second hollow element 31b having orifices and in such a way that the hollow protuberances 5 cooperate with the orifices in order to allow fluid communication between the first 31a and second 31b hollow elements. According to a particular embodiment, the orifices of the second hollow element 31b correspond to the opening of the second free ends 53 of the protuberances carried by the second hollow element 31b. Thus, it is possible to manufacture identical hollow elements 31 and then make them cooperate to form the heat exchange bundle 3, which in particular makes it possible to facilitate the manufacturing method 100 of this heat exchanger 1.

The manufacturing method 100 then implements a heating and compression step E3 of the stack in order to allow the mechanical connection by brazing of at least the hollow protuberances 5 carried by the first hollow element 31a with the periphery of the orifices carried by the second hollow element 31b in order to form a sealed mechanical connection between the first 31a and second 31b hollow elements. Thus, the manufacturing method 100 is simple and quick to implement, in particular due to the reduction in the constituent elements of the heat exchange bundle 3 of the heat exchanger 1.

Alternatively, the stack may further comprise two end elements 38, 39 (visible in the figure 1 ) arranged on either side of the superposition of hollow elements 31 and parallel to these hollow elements 31. Each end element 38, 39 has a face arranged opposite a face of a hollow element 31. This face of the end elements 38, 39 is smooth and intended to be brazed with the hollow elements 31 in the stack. According to a particular embodiment, the face of the hollow elements 31 arranged opposite the end elements 38, 39 has hollow protuberances 5 in order to form the space 37' for the passage of the second fluid F2 and the brazing of the end elements 38, 39 with the adjacent hollow elements 31. These hollow protuberances 5 may have an opening for the passage of the first fluid F1. This opening is obstructed by the end elements 38, 39 during the formation of the sealed mechanical connection by brazing between the adjacent elements 31, 38, 39.

The manufacturing method 100 may include a final step of fixing (not shown) the input 11 and output 13 (visible on the figure 1 ) for the first fluid F1.

The various embodiments described above are examples provided for illustrative and non-limiting purposes. Indeed, it is entirely possible for a person skilled in the art to envisage other shapes for the protuberances 5 than those described above without departing from the scope of this description. Furthermore, a person skilled in the art may envisage a greater number of hollow elements 31 in fluid communication with each other without departing from the scope of this description.

Thus, obtaining a heat exchanger 1 having improved heat exchange capacities compared to those known from the prior art and having a good mechanical strength while having a limited number of parts is possible thanks to the heat exchanger 1 having a heat exchange bundle 3 as defined above. In particular, the presence of protuberances 5 allows the joining together of at least the various adjacent hollow elements 31 of the heat exchange bundle 3 and allows an increase in the heat exchange surface improving the exchanges between the first F1 and second F2 fluids. On the other hand, the joining of the various adjacent hollow elements 31 of this heat exchange bundle 3 by brazing at the level of the protuberances 5 makes it possible to simplify the structure of the heat exchange bundle 3 and also to ensure good mechanical strength of this heat exchange bundle 3 and therefore of the heat exchanger 1. In addition, the presence of hollow protuberances 5 allowing fluid communication between at least a first 31a and a second 31b hollow element allows an improvement in the homogenization of the temperature of the first fluid F1 and therefore an improvement in its heat exchanges with the second fluid F2.

Claims (9)

1. Heat exchanger (1), notably for a motor vehicle, comprising a heat-exchange core (3) for the exchange of heat between at least a first fluid (F1) and a second fluid (F2), said heat-exchange core (3) being made up of at least two superposed hollow elements (31) configured to form, respectively, a canal (35) inside which the first fluid (F1) is intended to circulate, and to allow the second fluid (F2) to circulate in a space (37) between the superposed hollow elements (31),

   such that at least one hollow element (31) of the heat-exchange core (3) exhibits a plurality of protuberances (5) extending into the space (37) for the circulation of the second fluid (F2), said protuberances (5) forming the connection between two adjacent hollow elements (31), and characterized in that

   at least a first hollow element (31a) and a second hollow element (31b) which are arranged facing one another are in fluidic communication with one another via at least one hollow protuberance (5) borne by at least one of the first (31a) and/or second (31b) hollow elements, said hollow elements (31) comprising transverse partition walls (9) obstructing a section of the canal (35) so that the first fluid (F1) circulates between two adjacent hollow elements (31) in fluidic communication.
2. Heat exchanger (1) according to the preceding claim, characterized in that the first hollow element (31a) bears at least one hollow protuberance (5) collaborating with an orifice made in the second hollow element (31b) positioned facing the at least one hollow protuberance (5) of the first hollow element (31a), said hollow protuberance (5) providing the fluidic communication between the first (31a) and second (31b) hollow elements and forming a fluidtight connection with the orifice.
3. Heat exchanger (1) according to Claim 1, characterized in that the first (31a) and the second (31b) hollow elements each have at least one hollow protuberance (5), the hollow protuberance (5) borne by the first hollow element (31a) having an end that collaborates with an end of the hollow protuberance (5) borne by the second hollow element (31b) and forming a fluidtight connection with this hollow protuberance (5) of the second hollow element (31b) so as to allow fluidic communication between the first (31a) and second (31b) hollow elements.
4. Heat exchanger (1) according to any one of the preceding claims, characterized in that the plurality of protuberances (5) borne by the at least one hollow element (31) are hollow protuberances (5) allowing fluidic communication between the first (31a) and the second (31b) hollow elements.
5. Heat exchanger (1) according to any one of the preceding claims, characterized in that the hollow protuberances (5) have a shape of constant cross section having a first end (51) positioned in contact with a face of the hollow element (31) bearing the protuberance (5) and a free second end (53) arranged at the opposite end from the first end (51) and in contact with the adjacent hollow element (31).
6. Heat exchanger (1) according to any one of Claims 1 to 4, characterized in that the hollow protuberances (5) have a shape of variable cross section having a first end (51) positioned in contact with a face of the hollow element (31) bearing the hollow protuberance (5) and a free second end (53) at the opposite end from the first end (51) and arranged in contact with the adjacent hollow element (31), said first end (51) having a cross section the area of which is greater than that of the free second end (53).
7. Heat exchanger (1) according to Claim 6, characterized in that the hollow protuberances (5) have a leading wall (55) and a trailing wall (57), the leading wall (55) being the first to come into contact with the first fluid (F1) as it passes the hollow protuberance (5) .
8. Heat exchanger (1) according to Claim 7, characterized in that the leading wall (55) of the hollow protuberance (5) and the canal (35) of the hollow element (31) form an angle (α) comprised between 0° and 90° (end-points excluded) and notably comprised between 15° and 60°.
9. Heat exchanger (1) according to either one of Claims 7 and 8, characterized in that the trailing wall (57) of the hollow protuberance (5) and the canal (35) of the hollow element (31) form an angle (β) comprised between 90° and 180° (end-points excluded) and notably comprised between 105° and 150°.

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