FR2968750A1 - Heat-exchanger i.e. condenser, for exchanging heat between e.g. cooling fluid and water-glycol in air-conditioning circuit of motor vehicle, has covers in contact with surface of collectors in order to define chamber for fluid - Google Patents

Abstract

The heat-exchanger i.e. condenser (1), has two distribution chambers for distributing fluid (F1) i.e. cooling fluid, respectively, for an input (9a) and an outlet (9b). The distribution chambers include collectors (11a, 11b) that are integrally formed with two surfaces, which are arranged opposite to each other. One of the surfaces is provided with multiple branches (19) that are inserted between ends (5a, 5b) of tubes (5). Covers (13a, 13b) are provided for closing the respective chambers, and are in contact with the other surface in order to define a chamber for the fluid.

Description

The invention relates to heat exchangers, in particular for motor vehicles.

It relates more particularly to a heat exchanger comprising an alternating stack of channels for the circulation of a first fluid and channels for the circulation of a second fluid. Such heat exchangers can be used, for example, as condensers in particular for a motor vehicle air conditioning circuit. The first fluid may then be constituted by a refrigerant fluid and the second fluid by a cooling fluid such as glycol water. There are known heat exchangers of this type made by stacked plate technology having corrugations to disturb the flow of the two fluids. These plates generally have raised peripheral edges which are assembled together in a sealed manner to delimit between the plates of the first and second circulation channels for the respective fluids. The disadvantage of such plates is that they offer little modularity as regards the size and the adaptation of the passage sections according to the properties of the fluids. Moreover, problems of soldering, and thus of sealing and resistance to pressure, may appear at the level of the fluid passages. According to a known solution of a heat exchanger, in particular a condenser, is composed of tubes whose ends are received in individual tips, also called "staples", which communicate with each other through lateral openings.

However, it is necessary to assemble each tube with the tips one by one, and this may require the establishment of polarizer for this assembly. This solution therefore requires the manipulation of a large number of individual pieces and generates an assembly that can be long and complex. In addition, this solution requires drilling the tubes to ensure the circulation of the fluid. The object of the invention is to overcome these problems of the prior art by simplifying the assembly of such heat exchangers. For this purpose, the subject of the invention is a heat exchanger between a first and a second fluid comprising a bundle of heat exchange tubes and two respectively inlet and outlet distribution boxes for the first fluid characterized by what said distribution boxes respectively comprise: a collector formed in one piece and having a first face with a plurality of parallel branches configured to be interposed between the ends of said tubes and a second face opposite to the first face, 10 - a associated lid closing said dispensing box and cooperating with said second face of said manifold so as to define at least one chamber for the first fluid. Said exchanger may further comprise one or more of the following characteristics, taken separately or in combination: said exchanger is a condenser, and the first fluid is a refrigerant and the second fluid is a cooling fluid; said cooling fluid comprises water supplemented with an antifreeze; said fluids circulate perpendicularly; said collector has a general shape of substantially a comb; Said manifold comprises a plurality of communication conduits opening into housings formed by two consecutive branches, for the passage of the first fluid between said distribution box and said tubes; said communication conduits are made substantially parallel to said branches of the comb form; The second face of said collector comprises at least a first groove delimited by two protrusions in contact with said cover; the second face of said collector comprises at least two first communicating grooves, and said protuberances delimiting said first grooves comprise a predefined number of second communication grooves between said first grooves; Said grooves are made substantially perpendicular to said first grooves; said prominences are of generally convex general shape whose convexity is oriented towards said associated cover; Said lid has an opening configured to be connected to a circuit of the first fluid; said lid has a convex portion whose convexity is oriented outwardly of said dispensing box, and said opening is made in said convex portion of said lid; Said convex portion has a generally oblong general shape; said opening has a generally circular general shape; said convex portion has substantially at its center a circular region in which said opening is formed and has on either side of this circular region a substantially oblong shape of smaller diameter than said circular region; said cover has in cross section a generally "C" shape with two opposite branches, so as to envelop said collector; said cover comprises fixing means made in one piece with said cover; Said fastening means are formed at the periphery of opposite branches of the "C" shape; said fixing means comprise crimping tabs; said exchanger comprises end plates of substantially flat shape superimposed on either side of the stack of said tubes; Said exchanger comprises side plates respectively comprising a substantially curved portion having an opening for the passage of the second fluid; said end plates have on their peripheral rim a protuberance of complementary shape of said curved portion of said side plates, to close the exchanger tightly;

Said exchanger is assembled by brazing.

Other features and advantages of the invention will emerge more clearly on reading the following description, given by way of illustrative and non-limiting example, and the appended drawings in which: FIG. 1 illustrates a perspective view of a heat exchanger, FIG. 2 is an exploded view of the exchanger of FIG. 1, FIG. 3 is a side view of the exchanger of FIG. 1, FIG. 4a is a first sectional view according to FIG. 2 of Figure 3, Figure 4b is a second sectional view along the line II-II of Figure 3, Figure 5 is a partial view of an alternative embodiment of a heat exchanger, the FIG. 6 is a first perspective view of a manifold of a distribution box of the exchanger of FIG. 1, and FIG. 7 is a second perspective view of the collector of FIG. 6.

In these figures, the substantially identical elements bear the same references.

FIGS. 1 to 3 show a heat exchanger 1 between a first F1 and a second fluid F2. This exchanger 1 is for example a condenser 1 in an air conditioning circuit (not shown), in particular a motor vehicle, for a heat exchange between a first refrigerant F1 fluid for example and a second cooling fluid F2. The cooling fluid F2 may comprise water containing an antifreeze, for example a glycol. To facilitate understanding of the figures, the connections of the exchanger 1 to the circulation circuits of these fluids F1, F2 are not illustrated. As can be seen in FIG. 2, the exchanger 1 comprises a bundle 3 formed by a stack of tubes 5 for the circulation of the first fluid F1 in the tubes 5 and for the circulation of a second fluid F2. between the tubes 5. This beam 3 is received in an envelope or casing 7 detailed later. The tubes 5 are according to the illustrated example flat tubes, that is to say of small thickness, arranged parallel to each other and having the same length L. This gives a beam 3 of generally parallelepipedal shape of length L, of width 1, and with a stack of tubes 5 in the dimension of the height h. Likewise, the exchanger 1 (FIG. 1) has a generally parallelepipedal general shape.

The stack of the beam 3 (better visible in FIGS. 4a and 4b) thus defines first circulation channels C1 for the first fluid F1 in the tubes 5 and second circulation channels C2 for the second fluid F2 between the tubes 5. Each tube 5 can define a single first channel C1 or alternatively several first channels C1, as shown in FIG. 5, in which three first channels C1 are defined by a tube 5. Moreover, it is possible to provide in these first channels C1 disturbance fins (not shown) having a shape creating turbulence in the flow of the first fluid F1. These fins (not shown) can for example be fixed by brazing to the tubes 5. In known manner, these fins (not shown) can be made in the form of corrugated inserts, formed for example from a metal strip which is deformed to form the undulations. Each corrugated spacer may be arranged to contact respective inner walls of a tube 5 by end regions of the corrugations. Furthermore, it is possible to provide in the second channels C2 disrupters 8, an example of which is shown diagrammatically and partially in FIG. 5. In this case, the beam 3 comprises an alternating stack of tubes 5 and disrupters 8. According to the embodiment of FIG. 5, the disrupters 8 are in the form of plates which extend between two tubes 5. In this case, the disrupters 8 are in the form of a embossed wall, or having crenellated patterns. These wall elements having crenellated patterns are for example arranged in rows staggered with respect to each other.

This disruptive plate 8 is for example brazed on each side to the side surfaces of the tubes 5 defining a second channel C2.

In addition, the respective ends 5a, 5b on either side of the tubes 5 are received in distribution boxes 9a, 9b (FIGS. 2 and 3) jointly formed by collectors 11a, 11b and covers 13a, 13b. The collector 11a, 11b is disposed at the end of the assembly of the tubes 5, and allows the assembly with the cover 13a, 13b associated. The cover 13a, 13b protects the collector 11a, 11b and closes the distribution box 9a, 9b. In fact, referring to FIGS. 2, 4a and 4b, the collector 11a on the right-hand side (for illustrative purposes) in the figures forms, in conjunction with the associated cover 13a, an inlet distribution box 9a for the first fluid F1. , while the collector 11b located on the left side (for illustrative purposes) in the figures, forms together with the associated cover 13b an output distribution box 9b for the first fluid F1. The collector More specifically, concerning the assembly of the tubes 5 to the collectors 11a, 11b; firstly the first ends 5a of the tubes 5 are received in the manifold 11a and secondly the second ends 5b of the tubes 5 are received in the manifold 1 lb. A single manifold 11a, 11b (best seen in FIGS. 6 and 7) formed in one piece receives a plurality of ends 5a, 5b of tubes 5. To do this, a collector 11a, 11b has a plurality of housings 15 of the tubes 5. According to the illustrated embodiment, this plurality of housings 15 of a collector 11a, 11b is obtained thanks to a substantially comb-shaped shape of the collector 2968750 -7- 11a, 11b . This comb shape comprises a base 17 and a plurality of parallel branches 19 extending in the same direction from the base 17. These branches 19 are configured to be interposed between the ends 5a, 5b of the tubes 5 as can be seen better. in Figure 4a. The branches 19 are found at the inter-tube disruptors 8 when there are. Thus, two consecutive branches 19 facing each other form a housing 15 for receiving an end 5a, 5b of a tube 5. The distance between two adjacent tubes 5 therefore corresponds substantially to the thickness of material of a branch 19, and possibly at the height of interfering interferers 8. Or, the distance between two consecutive branches 19 of a manifold 9a, 9b thus corresponds substantially to the height of a tube 5. These branches 19 allow to achieve a seal. The ends 5a of the tubes 5 are thus held in the manifold 11a and the ends 5b of the tubes 5 are held in the manifold 11b.

In order to allow the passage of the first fluid F1 between a distribution box 9a, 9b and the tubes 5, communication ducts 21 are arranged in the base 17 of a collector 11a, 11b (see FIGS. 6 and 7) and They open into the housings 15. Each communication duct 21 is arranged so as to be facing one end 5a, 5b of tube 5. As can be seen in FIG. 7, these communication ducts 21 are made substantially parallel to the branches 19 defining the housings 15. The first fluid F1 thus enters a tube 5 or leaves, at its end 5a, 5b at the level of the communication conduit 21, without it being necessary to provide additional perforation in the tube 5. A heat exchanger 1 is thus produced in which the first fluid F1 enters the exchanger 1 via the input distribution box 9a, circulates in the tubes 5 of the bundle 3 while passing through through the commu ducts 21, then arrives in the output distribution box 9b, still through the communication conduits 21, to exit the heat exchanger 1, as shown by the arrows F1, in Figures 1 and 2.

In order to define the internal volume of the distribution box 9a, 9b, otherwise called one or more chamber (s) 22 for the first fluid F1, a collector 9a, 9b has at least one first groove 23 delimited by two prominences. 25, as can be seen in FIG. 7. The prominences 25 delimiting the first grooves 23 are made on the opposite side to the receptacles 15 for receiving the ends 5a, 5b of the tubes 5 and are thus opposite the associated lid 13a, 13b. The prominences 25 therefore come into contact with the associated cover 13a, 13b during assembly of the distribution box 9a, 9b. Thus, a collector 9a, 9b comprises: a first face 27 (FIG. 6) having the receptacles 15 for receiving the ends 5a, 5b of the tubes 5, and a second face 29 (FIG. 7) opposite the first face 27, co-operating with the cover 13a, 13b associated. In the example illustrated in FIG. 7, the second face 29 has at least three first grooves 23, each being delimited by two protuberances 25. Four protrusions 25 are therefore provided to delimit these first three grooves 23.

These prominences 25 are for example of generally convex general shape or in other words are curved. This convexity or bulge is oriented (e) to the associated cover 13a, 13b and comes into contact therewith. In addition, second grooves 31 substantially perpendicular to these first grooves 23 and protuberances 25 are formed in the prominences 25 to allow the first grooves 23 and thus the defined chambers 22 to communicate with each other. The production of several first communicating grooves 23 makes it possible to homogenize the distribution of the fluid FI in the tubes 5. Indeed, the fluid F1 arriving in the distribution box 9a, 9b, through an opening 33 provided on the cover 13a, 13b is directed by these first grooves 23 communicating with each other more homogeneously towards the different channels CI tubes 5 of the stack. The number of second grooves 31 enabling this communication between the first grooves 23 is defined as a function of the exchanger 1 and the fluid F1. By way of example, FIGS. 2 and 7 illustrate a variant with a predefined limited number of second grooves 31 and in FIG. 5 another variant with a plurality of second grooves 31 which are thinner than in FIG. 7, with a tight step.

This particular form of the collector 9a, 9b with, on the one hand, these housings 15 for the tubes 5 and, on the other hand, these first grooves 23 and these bulges 25 for defining the communicating chambers 22 for the first fluid F1, is for example obtained by extrusion then machining.

The cover The cover 13a, 13b has a general shape complementary to that of the collector 11a, 11b associated to jointly form the distribution box 9a, 9b. More specifically, the cover 13a, 13b has an inner face shaped to be complementary to the second face 29 (Figures 5 and 6) of the collector 11a, 11b, as can be seen in Figure 4a. In particular, the cover 13a, 13b has in cross section a generally "C" -shaped general shape so as to envelop the associated collector 9a, 9b and define a sealed distribution box 9a, 9b.

In addition, to allow the circulation of the first fluid FI in the exchanger 1, each distribution box 9a, 9b comprises, as previously mentioned, an opening 33 configured to be connected to a circuit of the first fluid F1. Connectors for this connection are not shown to facilitate understanding of the drawings. The opening 33 may have, as in the illustrated example, a generally circular shape. This form of the opening 33 is provided complementary to the connector 30 (not shown) used connecting the distribution box 9a, 9b to the first fluid circuit Fi.

FIG. 5 shows a cover 13a, 13b of substantially flat shape, that is to say without hump or hollow.

As an alternative (FIGS. 1,2,4a, 4b) may be provided, in order to further homogenize the distribution of the fluid F1, the cover 13a, 13b has a convex or substantially convex portion, made for example by stamping, and the convexity is oriented towards the outside of the distribution box 9a, 9b, and therefore opposite the collector 9a, 9b associated. The opening 33 is in this case made in this convex part 35 or bulge. Referring to Figure 2, the convex portion 35 has a generally oblong general shape 37 to adapt to the horizontal extent of the tubes 5 in the beam 3. More precisely in the example shown, this oblong shape 37 s' extends parallel to the width dimension 1 of the tubes 5, over a distance d less than this width 1 substantially to the level of the end protrusions. Thanks to this oblong shape 37, the fluid F1 arriving through the opening 33 in the input distribution box 9a is distributed more evenly over the horizontal extent of the tubes 5 stacked. Likewise, the fluid F1 exiting the tubes 5 via the opening 33 in the output distribution box 9b is distributed more homogeneously to the outlet box 9b. The dimensions of the oblong shape 37 are therefore chosen in a manner suitable for the homogeneous distribution of the high pressure fluid F1 without generating losses.

In addition, in the case where the opening 33 is of substantially circular shape, the convex portion 35 of the cover 13a, 13b may have, at the right of this opening 33, a region 39 of substantially circular shape and for example of larger diameter. the remainder of the oblong shape 37. Of course, this shape is to be adapted according to the shape of the opening 33. In the example shown, the convex portion 35 is substantially centered relative to the other. to the cover 13a, 13b and the opening 33 is substantially in the center of this convex portion 35. Thus, according to the illustrated embodiment, the convex portion 35 has substantially at its center a circular region 39 in which is practiced 5 opening 33, and on either side of this circular region 39 a substantially oblong shape 37. Of course, other alternative embodiments are conceivable for this convex part 35 and the opening 33. In addition, in case of variants of the connectors or pipes for the connection of the distribution box 9a, 9b to the first fluid circuit F1, only the cover 13a, 13b is to adapt and not all the distribution box 9a, 9b. the collector 11a, 11b can remain the same and only the cover 13a, 13b is changed by providing a shape adapted to these variants of connectors or tubings for connection to the fluid circuit F1.

Such a distribution box 9a, 9b formed by a manifold 11a, 11b in one piece and a cover 13a, 13b associated allows a simplified assembly of the distribution box 9a, 9b on the one hand and the heat exchanger 1 on the other hand, and an ease of adaptation to different manufacturer variants by changing only the cover 13a, 13b.

Furthermore, the distribution box 9a, 9b may comprise an additional part 41, as can be seen in the variant of FIG. 5, for fixing the cover 13a, 13b to the collector 11a, 11b. This piece 41 is for example fitted into a corresponding housing 43 of the collector 11a, 11b and clipped into corresponding openings 45 on the cover 13a, 13b associated. In the example illustrated in FIG. 5, this fastener 41 has a general shape similar to that of the protuberances 25 of the collector 11 a, 1 b, thus here substantially convex towards the associated cover 13 a, 13 b and includes complementary protrusions 47. openings 45 of the cover 13a, 13b.

Any other fixing means may be provided between the cover 13a, 13b and the associated collector 11a, 11b.

Alternatively or in addition, fixing means may be carried by the cover 13a, 13b and made in one piece with the cover 13a, 13b.

According to an alternative shown in Figures 1 and 2, the fixing means are for example crimping tabs 49 which can then be brazed. These crimping tabs 49 are for example arranged on the periphery of the two opposite branches of the "C" of the cover 13a, 13b. These crimping tabs 49 serve not only for fixing the collector 10 1a, 11b and the associated cover 13a, 13b but also for fixing the corresponding distribution box 9a, 9b on the casing 7. With regard to the embodiment of the 5, the fastening means formed in one piece with the cover 13a, 13b may comprise a tongue 49 'which can then be brazed to the casing 7. In addition, it is possible to provide lateral fastening means, for example also 51 side crimping tabs (Figure 2) for attachment to the housing 7. These crimping tabs 51 side can then be brazed during assembly of the exchanger 1.

The casing 20 Moreover, as previously mentioned, the beam 3 is housed in a casing 7. In the example illustrated, this casing 7 comprises two end plates 53, 53 'respectively disposed above the stack of tubes 5. so as to form a cover wall 53, and below the stack of tubes 5 so as to form a bottom wall 53 '. This casing 7 further comprises two opposite lateral walls 55 of generally rectangular shape so as to delimit together with the end plates 53, 53 'an open parallelepipedal shape to which are attached on both sides a distribution box 9a, 9b as defined above. The casing 7 also includes openings 57 for the entry and exit of the second fluid F2. In the example illustrated in the figures, these openings 57 are of substantially circular shape and are respectively formed in the two opposite side walls 55 of the casing 7. In order to define a chamber for the second fluid F2, it can be provided that the wall Lateral 55 presents at the right of this opening 57 a substantially convex or curved shape oriented towards the outside of the exchanger 1, as illustrated in FIGS. 1 and 2. This shape, which approximates that of a bath, is substantially for example by stamping.

According to an alternative embodiment (FIG. 5), the lateral wall 55 does not have a straight alignment along its entire length but substantially describes at the level of the opening 57 a curve 59 so that the lateral wall 55 moves away from the bundle 3 of 5. This spacing between a side wall 55 and the bundle 3 of tubes 5 thus defines a chamber for the second fluid F2.

In the example shown, the side wall 55 has a single slight curvature 59. It can be alternatively provided that the side wall 55 has on both sides of the opening 57 two curvatures 59, so that the side wall 55 is found substantially in the same right alignment on both sides of these curvatures 59.

The casing 7 thus delimits at the level of the side walls 55 a chamber for the fluid F2, which flows between the tubes 5. In the illustrated examples, the arrangement of the openings 33 of the cover 13a, 13b for the entry and exit of the first FI fluid, and openings 57 on the side walls 55 of the casing 7 for the inlet and outlet of the second fluid F2, is such that the two fluids FI and F2 circulate perpendicularly (see Figures 1 and 2) relative to to the other, to improve the heat exchange. Thus, during its course in the tubes 5 of the exchanger 1, the first fluid FI is in heat exchange relation with the second fluid F2 which circulates perpendicularly to the bundle 3 of tubes 5.

The end plates 53, 53 'of cover and bottom therefore have complementary shapes on the one hand of the beam 3 and on the other side of the side walls 55 of the casing 7 to form a sealed assembly. For this purpose, an end plate 53, 53 'has a generally rectangular general shape and has a peripheral rim 61 which bears against the side walls 55 of the casing 7. With regard to the variant illustrated in FIG. , the rim 61 has on either side a protuberance 63 of complementary shape of the convex shape of a side wall 55 to the right of the opening 57. And, as regards the variant illustrated in FIG. flange 61 follows the alignment and curvatures 59 of the side walls 55.

In addition, as shown in FIG. 5, the end plates 53, 53 'have on their rim 61 at least one tongue 63 suitable for coming into contact with a distribution box 9 a, 9 b to face. In the illustrated example, two tongues 63 are provided at the end of the rim in the dimension parallel to the width 1 of the beam 3, and respectively engage in a complementary space 65 provided on the distribution box 9a, 9b. The whole of the casing 7 can then be fixed to the bundle 3 and to the distribution boxes 9a, 9b at the moment of soldering of the exchanger 1. Assembly of the exchanger Thus, for the assembly of such an exchanger 1, the tubes 5 and possibly the disturbers 8 are superposed alternately. The end plates 53, 53 'are superposed on the stack of tubes 5 and the side walls 55 are positioned so as to form a parallelepiped open on two sides. The ends 5a, 5b are then inserted into the respective collectors 9a, 9b which are attached to the open faces of the exchanger 1. A cover 13a, 13b is then assembled to the respective collector 11a, 11b to form a box of distribution 9a, 9b. It is not necessary here to provide additional perforations for the passage of fluids in the tubes 5. In addition, it is not necessary to introduce one by one the ends 5a, 5b of the tubes 5 in individual collectors. This results in a simplification of assembly and manufacturing of the exchanger. The assembly is then fixed by brazing.

It is therefore understood that with such a distribution box 9a, 9b formed by a collector 11a, 11b made in one piece to receive the plurality of free ends 5a, 5b tubes on both sides, and by a 13a lid, 13b closing the dispensing box, it simplifies the manufacture of the tubes 5 since it is not necessary to provide passage for fluids and the assembly of the exchanger.

Claims (10)

REVENDICATIONS1. Heat exchanger between a first (F1) and a second (F2) fluid comprising a bundle (3) of heat exchange tubes (5) and two respectively inlet (9a) and outlet (9b) distribution boxes for the first fluid (F1), characterized in that said distribution boxes (9a, 9b) respectively comprise: a collector (11a, 11b) formed in one piece and having a first face (27) with a plurality of branches (19) parallels configured to be interposed between the ends (5a, 5b) of said tubes (5) and a second face (29) opposite the first face (27), a cover (13a, 13b) associated closing said distribution box (9a, 9b) and cooperating with said second face (29) of said manifold (11a, 1b) so as to define at least one chamber (22) for the first fluid (FI). 2. Heat exchanger according to one of claims 1, characterized in that said collector (11a, 1b) has a generally substantially comb shape. 3. Exchanger according to any one of the preceding claims, characterized in that said collector (nad l lb) comprises a plurality of conduits (21) for communication opening in housings (15) formed by two branches (19) consecutive, for the passage of the first fluid (F1) between said distribution box (9a, 9b) and said tubes (5). 4. Heat exchanger according to any one of the preceding claims, characterized in that the second face (29) of said collector (11a, 1b) comprises at least a first groove (23) delimited by two protrusions (25) in contact with said cover (13a, 1 3b). 5. Heat exchanger according to claim 4, characterized in that: the second face (29) of said collector (11a, 1b) comprises at least two first grooves (23) communicating, and in that said protrusions (25) delimiting said first grooves (23) comprise a predefined number of second grooves (31) for communication between said first grooves (23). 6. Heat exchanger according to any one of the preceding claims, characterized in that said cover (13a, 13b) has an opening (33) configured to be connected to a circuit of the first fluid (FI), in that said cover (13a, 13b) has a convex portion (35) whose convexity is oriented outwardly of said dispensing box (9a, 9b), and in that said opening (33) is formed in said convex portion (35) said lid (13a, 13b). 7. Heat exchanger according to claim 6, characterized in that said convex portion (35) has a generally oblong general shape. 8. Heat exchanger according to any one of the preceding claims characterized in that said cover (13a, 13b) comprises fixing means (49,49 ', 51) made in one piece with said cover (13a, 13b). 9. Heat exchanger according to any one of the preceding claims, characterized in that it comprises end plates (53, 53 ') of substantially flat shape superimposed on either side of the stack of said tubes ( 5). 10. Exchanger according to any one of the preceding claims, characterized in that it comprises side plates (55) respectively comprising a substantially curved portion having an opening (57) for the passage of the second fluid (F2).