FR2874082A1 - HEAT EXCHANGER WITH EASY ASSEMBLY AND IMPROVED HEAT TRANSFER - Google Patents

Abstract

The invention relates to a heat exchanger comprising a body containing a series of first (18) and a series of second (20) fluid flow channels. The body is equipped with: a first slotted element (2) comprising at least a first groove (14) and at least a first rib (6), each first rib (6) housing at least one of the first fluid flow channels (18); and a second slotted element (4) comprising at least a second rib (8) and at least a second groove (16), each second rib (8) housing at least one of the second fluid flow channels (20). According to the invention, the first (2) and second (4) body elements engage such that each first rib (6) and each second groove (8) are housed in a second groove (16) and a first groove (14) respectively.

Description

VCL1551.FRD.wpd

  The invention relates to the field of heat exchangers, for example for an air conditioning circuit of a motor vehicle.

  More particularly, it relates to a heat exchanger comprising a body in which are formed a series of first fluid circulation channels and a series of second interchanged fluid circulation channels.

  Such a heat exchanger is known for example from JP 2003121086, which describes the use of an extruded profile as a body, in which are formed first and second fluid circulation channels. It is necessary to connect the first and second fluid circulation channels to separate manifolds or manifolds. To do this, JP 2003-121086 provides that the section crosses transversely a first and a second collector, both of cylindrical shape. A first cut of the profile wall at the first cylindrical collector contacts the inside of the cylindrical collector and the first fluid circulation channels. A second cut made at the second cylindrical collector communicates the interior of the second cylindrical collector and the second fluid circulation channels. Although the production of the body of the heat exchanger in the form of an extruded profile gives it good mechanical resistance to pressure, the connection of the fluid circulation channels to the collectors is difficult to implement and makes it particularly difficult to use. assembly of such a heat exchanger.

  JP 2003-279276 discloses a heat exchanger whose body is in the form of a single piece in which are formed a series of aligned fluid circulation channels 2874082 2. At the ends of the one-piece piece are then produced series of cuts for making series of teeth which are traversed by the fluid circulation channels. For each end of the one-piece piece, the teeth of the series of teeth are alternately folded on one side and the other of a plane containing the bulk of the one-piece piece, defining a series of first teeth and a series of second teeth. The teeth are then received in separate cylindrical or collecting manifolds, which can be connected to the rest of the air conditioning circuit.

  Such a heat exchanger is difficult to make, in particular because of the operation of cutting and folding the teeth.

  The object of the invention is in particular to overcome the aforementioned drawbacks by proposing a heat exchanger of the type mentioned above, in which the body comprises a first crenellated profile body element comprising at least a first groove and at least a first groove. rib, each first rib housing at least one of the first fluid flow channels, and a second crenellated body member having at least one second rib and at least one second groove, each second rib housing at least one second fluid flow channels, the first and second body members interlocking so that each first rib and each second rib are received respectively in a second groove and a first groove.

  In a preferred embodiment, the profile of the first body member includes a plurality of first grooves alternating with a plurality of first ribs and the profile of the second body member includes a plurality of second ribs alternating with a plurality of second grooves.

  Advantageously, each first rib houses one of the first fluid circulation channels, and each second rib houses one of the second fluid circulation channels, so that the first and second channels are interposed. This configuration makes it possible to obtain good heat exchange performance.

  Preferably, each first groove and each second rib are of conjugate shapes so that each first groove completely houses a second rib, and each second groove and each first rib are of conjugate shapes so that each second groove completely houses a first rib. Finally, this configuration improves the heat exchange between the fluid flowing through the channels housed in the first rib or ribs and the fluid flowing through the channels housed in the second rib or ribs. This form cooperation also improves the pressure resistance of the assembled body members, since each rib of one body member contributes to supporting the force resulting from the deformation of the adjacent rib of the other body member. Similarly, the pressures exerted by the fluids traversing two adjacent ribs of different body elements, tend to compensate for themselves through this form cooperation.

  In a preferred embodiment of the invention, the first body member comprises a first junction face and the second body member comprises a second junction face, each first and second rib respectively projecting from the first and second faces of the junction face. junction so that each first and second rib jointly defines the first and second junction faces respectively a first and a second groove. This configuration is easy to implement because only the rib or ribs projecting from the joining faces are to be realized. In addition, this configuration makes it easier to nest body elements.

  As an alternative embodiment of the invention, the second body member further comprises a third junction face of which projects at least one third rib defining at least one third groove, each third rib housing at least one of third channels of fluid circulation. The exchanger then further comprises a third crenellated body body member having a fourth junction face from which projects at least one fourth rib and at least one fourth groove, each fourth rib housing at least one of the fourth fluid flow, the second and third body members interlocking so that each third rib and each fourth rib are received respectively in a fourth and a third groove.

  In this case, it is expected that the second and third junction faces of the second body member are opposed, in that each second rib is facing a third groove and in that each third rib is opposite a second groove, which reduces the material used in the construction of the heat exchanger and in particular the material present between the fluid circulation channels, which impairs the heat exchange.

  Advantageously, at least one of the body members has a free face opposite a junction face, said free face having at least one additional groove facing a rib of the junction face. This additional groove allows "removal" of the material and thus makes the manufacture of the heat exchanger less expensive raw material. The heat exchanger is also lighter and this removal of material prevents unnecessary heat storage at the free face.

  Preferably, each rib of each junction face extends on either side of said junction face so as to form in each case a first and a second tooth. The heat exchanger then comprises first and second fluid collectors attached to each body element, the first and second collectors being each provided with holes of a shape adapted to accommodate at least part of said teeth so that the circulation channels of the fluid flow each into a first and a second collector. This is a simple way of connecting the fluid circulation channels to the collectors, which are then connected to the rest of the air conditioning circuit, for example.

  Advantageously, each first rib of said first body member has bent portions each connecting a tooth to a central portion of the first rib so that said first and second teeth are respectively disposed in planes inclined with respect to said first junction face, this allows to shift the collectors of the plane in which the body of the heat exchanger is located in order to gain space and not to interfere with the support of the second body member coming into interlocking with the first body member.

  For the same reasons, in the preferred embodiment, each second rib of said second body member has a bent portion connecting a first and second teeth to a central portion of said second rib so that each tooth is disposed in an inclined plane. relative to said second junction face.

  In said embodiment of the invention, it is advantageous to ensure that each fourth rib of said third body member has a bent portion connecting a first and a second tooth to a central portion of said fourth rib so that each tooth is disposed in a plane inclined relative to said fourth junction face. In this case, there is enough space to accommodate adjunct collectors at the second body member.

  It is then possible to ensure that each first and second tooth of the second and third junction faces are respectively received in the same first collector on the one hand and in the same second collector on the other hand.

  In all of the above embodiments, it is preferable that the first fluid flow channels and the second fluid flow channels are formed in the first and second grooves respectively so that the first fluid flow channels and the second fluid circulation channels are aligned. This makes it possible to reduce the gap between the fluid circulation channels in order to improve the heat exchange.

  Preferably, each body member is formed as a profiled and integral piece, obtained, for example, by extrusion, which constitutes a simple implementation of the invention. In addition, the realization of the body members as one-piece pieces provides the best resistance to pressure possible. Extrusion makes it easy to make the fluid circulation channels.

  Advantageously, each first rib and each second groove are of jointly selected dimensions in a tight fit. This makes it possible to grip the body elements in force and thus to do without a brazing or soldering operation. In a brazing operation, the filler metal is capable of weakening the corrosion resistance of the body and reducing its mechanical resistance to the pressure exerted by the fluids. In the case of brazing as weld, the heating and cooling of the body elements induce a change in their metallographic structure; these modifications are likely to reduce the resistance to pressure of the exchanger body.

  The ribs of at least one of the body members may have a trapezoidal or square section.

  Preferably, each first rib, each second groove, each first groove and the second ribs are of identical section so that the first and second body members are of identical shape. Thus, the body elements are made as identical pieces which are then matched. This reduces costs and facilitates the manufacture of the heat exchanger.

  Advantageously, the body elements, each of whose ribs has bent portions, are bent in the vicinity of their ends so as to form said bent portions, which makes it possible to bend all the ribs in the same manufacturing operation.

  In a particularly advantageous embodiment, the heat exchanger is made in the form of an internal heat exchanger for an air conditioning circuit.

  Other features and advantages of the invention will become apparent upon consideration of the following detailed description, and the accompanying drawings, in which: FIG. 1 is a partial perspective view of a heat exchanger according to FIG. invention in a preferred embodiment, - Figure 2 is a partial sectional view of the exchanger of Figure 1 along a plane (X, Z); - Figure 3 is a partial sectional view of the heat exchanger; FIG. 4 is a partial sectional view of the heat exchanger of FIG. 1 along a plane (X, z) in FIG. FIG. 5 is a perspective view of a detail of FIG. 1; FIG. 6 is a partial perspective view of a heat exchanger according to the invention in another embodiment of FIG. embodiment, - Figure 7 is a sectional view of the heat exchanger of Figure 6 along a plane (X, Z), and FIG. 8 is a diagram illustrating a preferred embodiment of the heat exchanger of FIG. 1, in an air conditioning circuit, and FIG. 9 is a sectional view of a heat exchanger according to the invention in FIG. another embodiment.

  The accompanying drawings may not only serve to complete the invention, but may also contribute to its definition, if appropriate.

  FIG. 1 illustrates a heat exchanger 1 according to the invention in a first embodiment, seen in perspective.

  The heat exchanger 1 consists of a first body element 2 and a second body element 4, both of elongated shape and of generally rectangular shape, made in the form of metal sections, the section of which is illustrated in Figure 2, which is a cross section of the body elements 2 and 4 assembled in a plane (X, Z).

  As shown in Figure 2, the body members 2 and 4 have crenellated profiles composed of first and second longitudinal ribs 6 and 8 respectively, of square section running along the body members 2 and 4 respectively. The first 6 and second 8 longitudinal ribs respectively protrude from a first 10 and a second 12 substantially rectangular junction face and each respectively opposite to a free face also rectangular designated by the reference numerals 9 and 11.

  The second and first longitudinal ribs together with the first 10 and second 12 junction faces define a series of longitudinal grooves 14 and 16 of square section and whose dimensions are similar to the dimensions of the second 8 and first 6 longitudinal ribs respectively. Each first or second longitudinal groove 14 has the first or second junction face 12 as the bottom and the flanks of the first or second longitudinal ribs respectively. The first 6 and second 8 longitudinal ribs are traversed respectively by first 18 and second 20 longitudinal fluid circulation channels of circular section and intended respectively for the circulation of a first and a second fluid through the heat exchanger. heat.

  It should be noted that the terms first fluid and second fluid may designate the same fluid taken in different temperature and / or pressure states. For example, in an air conditioning circuit in which a gas such as carbon dioxide CO2 circulates, the term "first fluid" refers to the gas in a state of high pressure and high temperature while the term "second fluid" relates to that gas. same gas at a different point of the circuit in a state of low pressure and low temperature.

  The first longitudinal ribs 6 are in contact all around their perimeter with the periphery of the second longitudinal grooves 16 and the periphery of the second longitudinal ribs 8 are in contact with the perimeters of the first longitudinal grooves 16. In so doing, a heat exchange takes place between the first 18 and the second 20 fluid circulation channels via the first 2 and second 4 body members, themselves brought into thermal contact through the grooves and ribs.

  The tolerance on the dimensions of the first 6 and second 8 longitudinal ribs as well as the first 14 and second 16 longitudinal grooves intended to receive them is preferably chosen so as to ensure a tight fit between the first 2 and second 4 body members. In doing so, the assembly or the nesting of the first 2 and second 4 body elements can be done in force, for example by means of a press, and thus makes it possible to do without a weld, which night, in particular because of the necessary filler metal, thermal exchanges between the first 2 and second 4 body elements.

  FIG. 3 illustrates an alternative embodiment of the heat exchanger of FIG. 1, in which the first 9 and second 11 free faces of the first 2 and second 4 body elements respectively have series of additional longitudinal grooves 22 and 24 respectively. facing respectively the first 6 and second 8 longitudinal grooves and intended to remove material in order to reduce the raw material costs, to reduce the mass of the heat exchanger, and especially to avoid unnecessary heat loss, by the free faces, favoring their thermal insulation. This insulation is favored by the recess of part of the material.

  The first 2 and second 4 body members are curved or bent at either end of their respective ends at an angle of about 90. As the first 6 and second 8 longitudinal ribs bear on the first 14 and second 16 junction faces, the folding of the first 2 and second 4 body elements print to the first 6 and second 8 longitudinal ribs portions of the bent portions of the another of a substantially flat portion. The bent portions of the first longitudinal ribs 6 of the first body member 2 are designated by the numerical references 26 and 28, while the bent portions of the second longitudinal ribs 8 of the second body member 4 are respectively designated by the numerals 30 and 32. .

  The first longitudinal ribs 6 extend on either side of the first junction face 14, in the continuity of the bent portions 26 and 28, by first series of teeth 34, which are of identical section to the first longitudinal ribs 6. The first series of teeth 34 are traversed by the first fluid circulation channels 18. From the bent portions 26 and 28, the first series of teeth 34 are disposed in planes inclined at substantially 90 of the first junction face 14.

  Similarly, the second longitudinal ribs 8 of the second body member 4 extend on either side of the second junction face 16 by second series of teeth 36 whose section is identical to the section of the second longitudinal ribs 8 and which are traversed by the second fluid circulation channels 20.

  It is noted that the bent portions 26, 28, 30 and 32 separate the series of teeth 34 and 36 from the junction faces 14 and 16 opposite the other body member 2 or 4.

  Each series of teeth 34 and 36 is received in cylindrical fluid manifolds 40 and consist of two semi-cylindrical shells 42 and 44 assembled to one another. For each fluid manifold 40, one of the half-cylindrical half-shells 44 has a succession of holes 46 of identical section to the section of the first 34 and second 36 series 46 teeth. Each fluid manifold 40 thus receives the first 34 or second 36 series of teeth, so that the first 18 or second 20 fluid circulation channels open into the fluid manifolds 40. The junction between the fluid manifolds 40 and the remainder of a hydraulic circuit is provided via a nut system 48 adapted for connection of a fluid circulation hose and well known to those skilled in the art.

  Advantageously, the first 2 and second 4 body members are made as profiled monobloc pieces obtained by extrusion. The curvature of the first 2 and second 4 body members is achieved by a subsequent bending operation.

  Although it has been described here, first 6 and second 8 longitudinal ribs of square section, other shapes are possible, as shown in Figure 4, which has longitudinal grooves 6 and 8 of trapezoidal section, the large base is supported on the first 10 and second 12 junction faces. Similarly, the first 18 and second 20 fluid circulation channels have been described here of section and identical dimension, but it is conceivable to provide channels of different shape and / or different size.

  Such a heat exchanger 1 is particularly suitable for exchanging heat between fluids at very high pressure. Indeed, monobloc parts are particularly adapted to withstand high pressures. In addition, in the arrangement illustrated herein, the pressure within the first and second fluid flow channels tends to hold together the first 2 and second 4 body members.

  FIG. 6 is a perspective and partial view of a heat exchanger 50 according to the invention in an alternative embodiment, intended to allow a heat exchange between three circulating fluids inside the heat exchanger 50 FIG. 6 is to be considered in conjunction with FIG. 7, which is a cross-section of the heat exchanger 50 of FIG.

  In the heat exchanger 50 of FIG. 6, is interposed between the first 2 and second 4 body members, an intermediate body member 51, which is in the form of an elongate profiled piece of castellated profile. The intermediate body element 51 has a third junction face 52 and a fourth opposing junction face 54 facing each other and which are projecting respectively from the third 56 and fourth 58 longitudinal ribs of square section and of similar shape to the longitudinal ribs described above. The third and fourth longitudinal ribs 58 define a series of longitudinal grooves 60 and 62 together with the third 52 and fourth 54 junction faces.

  The third and fourth longitudinal grooves 60 and 62 fit exactly the first 6 and second 8 longitudinal grooves of the first 2 and second 4 body members as described above. The third 56 and fourth 58 longitudinal ribs are traversed by third 64 and fourth 66 fluid circulation channels of circular and identical section. Once nested, the first body member 2 and the intermediate body member 51 on the one hand and the second body member 4 and the intermediate body member 51 on the other hand, the first 18 and third 64 channels of Fluid flow is interspersed and aligned, as are the fourth and second fluid flow channels 66 and 66.

  Unlike the first 2 and second 4 body members, the intermediate body member 51 is not bent at its ends. The third 56 and fourth 58 longitudinal ribs extend on either side of the third 52 fourth 54 junction faces into third and fourth sets of teeth of identical section to unrepresented ribs. The third and fourth sets of teeth are arranged in identical planes to the plane containing most of the intermediate body element 51.

  The third and fourth sets of teeth are received in fluid manifolds 40 of the type described above. The bending of the first 2 and second 4 body elements makes it possible to provide sufficient space for disposing the fluid collectors 40 attached to the intermediate body element 51. Thus, the overall size of the heat exchanger of FIG. 6 is reduced. Of course, there have been described here third 56 and fourth 58 longitudinal ribs of square section, but other forms are possible for example trapezoidal sections.

  The exchanger object of the invention may comprise several elements of intermediate bodies 51 stacked and nested within each other. This, in order to increase the heat exchange capacity of the body for a given space in the direction Y. In this case, the intermediate body members 51 would be bent at their ends, so as to accommodate the corresponding collectors.

  Preferably, the body members are made of aluminum alloy, but other materials are conceivable.

  FIG. 8 illustrates an air conditioning circuit, for example for a motor vehicle, in which the heat exchanger 1 of FIG. 1 is integrated. The air conditioning circuit of FIG. 8 essentially comprises a compressor 80. A fluid refrigerant, for example carbon dioxide CO2, sent by the compressor 80 then passes through a gas cooler 82, from which it emerges in a high pressure and high temperature. At the outlet of the gas cooler 82, the fluid passes through the internal heat exchanger 1 by passing through the first fluid circulation channel 18 and is then expanded in a pressure reducer 84. The fluid thus expanded is then conveyed to an evaporator 86 and then to an accumulator 88, before joining the heat exchanger 1 in a state of low pressure and low temperature, through which it passes through the second fluid circulation channels 20. In this configuration, in which it is crossed by the same fluid in different states, the heat exchanger 1 is referred to as the internal heat exchanger. In this internal exchanger, the low pressure refrigerant exchanges heat with the high pressure fluid from the gas cooler. At the outlet of the heat exchanger 1, the fluid again wins the compressor 80 and so on.

  Figure 9 is a sectional view of a heat exchanger according to the invention in another embodiment. In this embodiment, the heat exchanger has a single second rib 8 housing all of the second fluid flow channels and interlocking in a single first rib 14 of the first body member 2. The body member 2 comprises two first ribs 6 housing each of several first fluid circulation channels 18 and interlocking in two second grooves 16 of the second body member 4.

  The invention is not limited to the embodiments described above, only by way of example, but encompasses all the variants that may be considered by those skilled in the art within the scope of the following claims.

Claims (22)

claims   A heat exchanger (1, 50) comprising a body having a series of first (18) fluid circulation channels and a series of second (20) fluid circulation channels, characterized in that the body comprises a first crenellated profile body member (2) having at least one first groove (14) and at least one first rib (6), each first rib (6) accommodating at least one of the first fluid circulation channels ( 18), and a second crenellated profile body member (4) having at least one second rib (8) and at least one second groove (16), each second rib (8) accommodating at least one of the second grooves fluid circulation (20), the first (2) and second (4) body members interlocking so that each first rib (6) and each second rib (8) are respectively received in a second groove (16) and a first groove (14).   Heat exchanger according to Claim 1, characterized in that the profile of the first body element (2) has a plurality of first grooves (14) alternating with a plurality of first ribs (6) and in that the profile of the first second body member (4) has a plurality of second ribs (8) alternating with a plurality of second grooves (16).   3. Heat exchanger according to one of claims 1 and 2, characterized in that each first rib (6) houses one of the first fluid circulation channels {18), and that each second rib (8) houses the one of the second fluid circulation channels (20), so that the first (18) and the second (20) channels are interposed.   4. Heat exchanger according to one of the preceding claims, characterized in that each first groove (14) and each second rib (8) are of conjugate forms so that each first groove (14) completely houses a second rib (8). ), and in that each second groove (16) and each first rib (6) are of conjugate shapes so that each second groove (16) completely houses a first rib (6).   5. Heat exchanger according to one of the preceding claims, characterized in that the first body member (2) comprises a first junction face (10) and in that the second body member (4) comprises a second face junction (12), each first (6) and each second (8) rib projecting respectively from the first (10) and second (12) junction faces so that each first (6) and second (8) rib defines together with the first (10) and second (12) junction faces respectively a first (14) and a second (16) groove.   6. Heat exchanger according to claim 5, characterized in that the second body member (51) further comprises a third (54) junction face which projects at least a third rib (58) defining at least a third groove (62), each third rib (62) housing at least one of third (66) fluid flow channels, and further comprising a third crenellated profile body member (4) having a fourth junction face (12) from which protrudes at least one fourth rib (16) and at least one fourth groove (8), each fourth rib (8) housing at least one of the fourth fluid circulation channels (20). ), the second (51) and third (4) body members interlocking so that each third (58) rib and each fourth (8) rib are received respectively in a fourth (16) and a third (62) groove .   7. Heat exchanger according to claim 6, characterized in that the second (52) and third (54) junction faces of the second body member (51) are opposite, in that each second rib (56) is opposite. a third groove (62) and in that each third rib (58) faces a second groove (60).   8. Heat exchanger according to one of claims 4 to 7, characterized in that at least one of the body members (2; 4) has a free face (9; 11) opposite to a junction face (10; 12), said free face (9; 11) having at least one additional groove (24) facing a rib (6; 8) of the junction face (10; 12).   9. Heat exchanger according to one of claims 4 to 8, characterized in that each rib (6; 8; 56; 58) of each junction face (10; 12; 52; 54) extends from side to side. another of said junction face so as to each time form a first and a second tooth (26) and in that it comprises first and second fluid collectors (40) associated with each body member (2; 51), the first and second collectors (40) each being provided with holes (46) of a shape adapted to accommodate at least part of said teeth (36) so that the fluid circulation channels (18; 20; 64; 66) each open into a first and a second collector (40).   10. Heat exchanger according to claim 7, characterized in that each first rib (6) of said first body member (21) has bent portions (26, 28) each connecting a tooth (36) to a central portion of the first rib (6) so that said first and second teeth (36) are respectively disposed in planes inclined with respect to said first junction face (10).   11. Heat exchanger according to claim 9 attached to one of claims 4 to 5, characterized in that each second rib (8) of said second body member (4) has a bent portion (30; 32) connecting a first and a second tooth (36) at a central portion of said second rib (8) so that each tooth is disposed in a plane inclined with respect to said second junction face (12).   12. Heat exchanger according to claim 9 attached to one of claims 6 to 8, characterized in that each fourth rib (8) of said third body member (4) has a bent portion (30; 32) connecting a first and a second tooth at a central portion of said fourth rib (8) so that each tooth is disposed in a plane inclined with respect to said fourth junction face (12).   13. Heat exchanger according to claim 12, characterized in that each first and second tooth (36) of the second (52) and third (54) junction faces are respectively received in the same first manifold (40) of a part and in the same second collector (40) on the other hand.   Heat exchanger according to one of the preceding claims, characterized in that the first fluid circulation channels (18) and the second fluid circulation channels (20) are arranged in the first (6) and the second ( 8) so that the first fluid circulation channels (18) and the second fluid circulation channels (20) are aligned.   15. Heat exchanger according to one of the preceding claims, characterized in that each body member (2, 4; 51) is formed as a profiled piece and monobloc.   16. Heat exchanger according to claim 15, characterized in that said profiled piece is obtained by extrusion.   17. Heat exchanger according to one of the preceding claims, characterized in that each first rib (6) and each second groove (16) are of jointly selected dimensions in a tight fit.   18. Heat exchanger according to one of the preceding claims, characterized in that each rib (6, 8) of at least one of the body members (2, 4) has a trapezoidal section.   19. Heat exchanger according to one of claims 1 to 17, characterized in that each rib (6, 8) of at least one of the body members (2, 4; 51) has a square section.   20. Heat exchanger according to one of the preceding claims, characterized in that each first rib (6), each second groove (16), each first groove (14) and the second ribs (8) are of identical section so the first (21) and second (41) body members are of identical shape.   21. Heat exchanger according to one of claims 9 to 12, characterized in that the body members (2, 4) of which each rib (6, 8) has bent portions (26, 28, 30, 32) are bent near their ends to form said bent portions (26, 28, 30, 32).   22. Heat exchanger according to one of the preceding claims, characterized in that it is realized in the form of an internal heat exchanger (1) for an air conditioning circuit.