FR2955928A1 - HEAT EXCHANGER - Google Patents

Abstract

The subject of the present invention is a heat exchanger (1) between a first fluid (HP) and a second fluid (BP), comprising a plurality of thermal modules (15, 15a, 15b, 15c) constituted respectively of a top plate ( 17) and a lower plate (19) assembled by defining between them, a first internal cavity (21) forming a first circulation channel for the first fluid (HP) and at least one circulation space (33) defined between two consecutive thermal modules (15, 15a, 15b, 15c). The circulation space (33) comprises fins (35), called second fins (35), of length (L_IFBP) of between 50 mm and 130 mm.

Description

Heat exchanger

The invention relates to a heat exchanger particularly for a motor vehicle, such as an internal heat exchanger disposed in an air conditioning circuit.

Today, heat exchangers for motor vehicles are known that consist of a bundle of tubes arranged in parallel on one or more rows, the tubes being intended for the circulation of a heat-transfer fluid through the heat exchanger.

Heat exchangers are also known comprising a plurality of superimposed plates configured to define heat transfer fluid circulation channels for heat exchange between the coolant and a surrounding medium.

However, such heat exchangers must be defined, from a dimensional point of view, in order to have optimum thermal efficiency, while limiting the pressure losses. The invention therefore aims to define the dimensional ranges of such a heat exchanger in which performance, thermal efficiency and pressure losses are optimized.

For this purpose, the subject of the invention is a heat exchanger between a first fluid and a second fluid, comprising a plurality of thermal modules consisting respectively of an upper plate and a lower plate assembled by defining between them a first cavity. inner forming a first circulation channel for the first fluid and at least one circulation space defined between two consecutive thermal modules forming a second circulation channel for the second fluid. More particularly, the circulation space comprises fins, called second fins, with a length of between 50 mm and 130 mm.

Advantageously, the second fins have a height of between 2.0 mm and 4.8 mm. Furthermore, the second fins have a pitch of between 1.3 mm and 1.8 mm, preferably 1.4 mm.

In addition or alternatively, the first internal cavity comprises fins, called first fins, of length between 50 mm and 130 mm. Preferably, the first fins have a height of between 1.0 mm and 1.5 mm. In addition, the first fins have a pitch of between 0.9 mm and 1.5 mm, preferably 1.0 mm.

Advantageously, the first fins and / or the second fins have a width of between 45.0 mm and 70.0 mm.

In addition, according to the present invention, the upper plate and / or the lower plate of each heat exchange module has a thickness of between 0.5 mm and 1.5 mm, preferably 1.0 mm.

According to an alternative embodiment, the plurality of thermal modules is disposed inside a housing. In this case, advantageously, the housing has a thickness of between 1.0 mm and 2.0 mm, preferably 1.5 mm. The present invention will be better understood, other characteristics and advantages will become apparent upon reading the following detailed description comprising exemplary embodiments given by way of illustration with reference to the appended figures, given as non-limiting examples, which may serve to complete the understanding of the present invention and the disclosure of its realization and, if appropriate, to contribute to its definition, in which: FIG. 1 is a partially exploded view of a heat exchanger according to FIG. FIG. 2 is a sectional view along a longitudinal direction (plane AA of FIG. 1) of the heat exchanger according to the present invention, FIGS. 3a and 3b show plates forming an exchange module. The heat exchanger of the heat exchanger according to the present invention, FIG. 4 is a side view of an alternative embodiment of a housing of the Figure 5 is a sectional view in a transverse direction (plane similar to the plane BB of Figure 1) of an alternative embodiment of the heat exchanger according to the present invention, and Figures 6 to 9 are graphs showing the evolution of the thermal efficiency and / or losses of the heat exchanger according to the present invention as a function of the dimensional parameters of the fins.

In FIGS. 1 to 4, identical elements bear the same references. Unless otherwise indicated, they have the same specificities and will not be detailed again.

FIG. 1 shows a heat exchanger 1, in particular for an air conditioning circuit of a motor vehicle, capable of ensuring a heat exchange between a first fluid, intended to be heated or cooled, and a second fluid, intended to absorb or give up heat with the first fluid.

In the described embodiment, the first fluid HP is a high-pressure, high-temperature fluid to be cooled by the second fluid, and the second fluid BP is a low-pressure, low-temperature fluid for absorbing heat from the first fluid. HP fluid. However, the present invention also covers all types of fluids used as a first fluid and a second fluid.

Figures 1 and 2 show a first embodiment. In these figures, the heat exchanger 1 comprises a housing 3 comprising a housing body 3a and a cover 3b, intended to be fixed to the housing body 3a. For this purpose, the housing body 3a has a plurality of fastening tabs 5 tightened on the lid 3b once the heat exchanger 1 assembled. The plurality of latching tabs 5 extend beyond a circumferential edge of the casing body 3a.

Furthermore, according to an alternative embodiment not shown, the housing body 3a and the lid 3b can be assembled by brazing, welding, ... The housing body 3a is obtained, for example, by a stamping process. Alternatively, the casing body 3a is obtained by extrusion, molding, ...

Advantageously, the attachment lugs 5, the circumferential edge and the bottom of the case body 3a are integral and form a unit, in that they are made from the same strip. The volume delimited by the circumferential edge and the bottom delimit a space which receives heat exchange modules 15 stacked flat in this space. In addition, the housing 3 has introducer ports for the first fluid HP and the second fluid BP, and discharge ports for the first fluid HP and second BP. In contrast to the engaging tabs 5 with respect to the circumferential edge, the housing body 3a is closed by a bottom through which a first inlet port 7 passes for the first HP fluid and a first outlet port 9 for the second BP fluid. Similarly, the lid 3b also has a second inlet port 11 for the second LP fluid and a second outlet port 13 for the first HP fluid.

The first inlet orifice 7 and the second outlet orifice 13 of the first fluid HP are sealingly connected to an air conditioning circuit (not shown) providing the supply of the first fluid HP in the heat exchanger 1. , the second inlet orifice 11 and the first outlet orifice 9 of the second LP fluid are sealingly connected to the air conditioning circuit (not shown) supplying the second LP fluid in the heat exchanger 1.

The housing 3, and more particularly the housing body 3a, houses a plurality of substantially identical heat exchange modules 15 superimposed in the housing 3 and fixed in the housing 3, for example by brazing.

Referring to the example of Figure 2, three heat exchange modules 15 are assembled in the housing 3, namely: a lower heat exchange module 15a, disposed at the bottom of the housing 3, a module of higher heat exchange 15b, disposed on the top near the lid 3b, and an intermediate heat exchange module 15c, disposed between the lower heat exchange module 15a and the upper heat exchange module 15b.

Of course, it is possible to have several intermediate heat exchange modules 15c between the lower heat exchange module 15a and the upper heat exchange module 15b. Each heat exchange module 15 is composed of an upper plate 17 and a lower plate 19 assembled together. The upper plate 17 and the lower plate 19 are shown in more detail in FIG.

The upper plate 17 and the lower plate 19 are, for example, metal plates of generally parallelepipedal shape which have a small thickness, especially between 0.5 and 1.5 mm.

The upper plate 17 and the lower plate 19 therefore comprise, respectively, two small sides 39 and two large sides 40 alternately arranged along a contour 23 of the upper plate 17 and the lower plate 19.

At corners of the short side 39 and the long side 40 of the upper plate 17 and 15 of the lower plate 19, there is a protrusion 42 which extends in the same plane as the upper plate 17 and the lower plate 19.

The upper plate 17, respectively the lower plate 19, has two protuberances 42 having a rounded contour and comprising first and second connecting portions 27a and 27b arranged at each end. Advantageously, the first and second connecting portions 27a and 27b are disposed in the diagonal of the upper plate 17, respectively the lower plate 19.

The first embodiment has a heat exchanger 1 having a circuit of the first fluid HP and the second fluid BP in a single direction to define a circulation in 'l'. Alternatively, the circuitry of the first fluid HP and the second BP fluid can be made in two separate directions to define a circulation 'U'. Next to the protrusion 42 and on the remainder of the short side 39, the contour of the upper plate 17, respectively the lower plate 19, is inclined in the direction of the second connecting portion 27b, respectively the first connecting portion 27a. , placed opposite. This constitutes a notch whose function is to distribute the fluid in the spaces between the heat exchange modules 15. When the lower heat exchange module 15a, the upper heat exchange module 15b and the intermediate heat exchange module 15c are housed in the housing body 3a, the inclined contours delimit, with the inner wall of the housing body 3a and the lid 3b, an inlet chamber dedicated to one of the fluids, in particular the second fluid BP. The existence of the inclined contour allows to release a sufficient volume so that the second inlet port 11 is not obstructed by the upper heat exchange module 15b.

The upper plate 17 and the lower plate 19 are assembled by defining between them a first internal cavity 21, as shown in FIG.

For this purpose, the contour 23 of the upper plate 17 and the contour 23 of the lower plate 19 may be raised relative to an outer surface 31 of the upper plate 17, respectively the lower plate 19. The contours 23 of the upper plate 17 and the lower plate 19 are then contiguous so as to define the first inner cavity 21.

According to an alternative embodiment not shown, only one of the two plates (lower or upper) of the same heat exchange module 15 may comprise a raised contour, thus delimiting the first internal cavity 21.

The first internal cavity 21 forms a first circulation channel of one of the fluids, in particular the first fluid HP.

In the example shown in FIGS. 1 and 2 with three heat exchange modules 15, the heat exchanger 1 therefore comprises three first circulation channels. Preferably, the first circulation channels, thus formed, are parallel to each other, and have, for example, a height of between 1 mm and 1.5 mm.

First fins 25 may be disposed in the first inner cavities 21 to improve heat exchange between the first HP fluid flowing in the first channels and the second BP fluid.

By way of example, the first fins 25 take the form of a corrugated metal plate. The first fins 25 can be obtained by various processes such as stamping, extrusion, rolling, ...

For greater clarity, the first fins 25 are not shown on section A-A of FIG.

In addition, the heat exchanger 1 is assembled via junction portions 27 on the housing 3 and first and second connection portions 27a and 27b on the heat exchange modules 15. The first and second portions Connecting members 27a and 27b enable the heat exchange modules 15 to be assembled together by cooperating with first and second adjacent connecting portions 27a and 27b associated with a neighboring heat exchange module 15. The junction portions 27 make it possible to assemble the heat exchange modules 15 with the housing 3. More precisely, the bottom of the housing body 3a in contact with the lower module 15a has at least one junction portion 27. Similarly, the cover 3b in contact with the upper heat exchange module 15b also has at least one junction portion 27. Finally, each heat exchange module 15 has at least the first connecting portion 27a, respectively the second connecting portion 27b. More specifically, each upper plate 17 and each lower plate 19 comprises at least the first and second connecting portions 27a and 27b respectively placed at each end of the upper plate 17, respectively the lower plate 19, at the level of the protrusion 42 present on the small side 39 of the upper plate 17, respectively the lower plate 19.

In the example illustrated in FIGS. 1 and 2, the bottom of the case body 3a and the cover 3b respectively comprise a junction portion 27. The junction portions 27 cooperate respectively with the first inlet orifice 7 of the first HP fluid. and the second outlet port 13 of the first HP fluid.

The upper plate 17 and the lower plate 19 comprise, for their part, the first connecting portion 27a and the second connecting portion 27b.

As can be seen in FIGS. 1 and 2, the first connection portions 27 a of the heat exchange modules 15 are aligned with each other and with the junction portion 27 of the housing body 3 a. Similarly, the second connection portions 27b of the heat exchange modules 15 are aligned with each other and with the junction portion 27 of the cover 3b.

Thus, the junction portion 27 of the housing body 3a cooperates with the associated first connecting portion 27a of the lower plate 19 of the lower heat exchange module 15a, the first and second connecting portions 27a and 27b of the plate upper 17 of the lower heat exchange module 15a cooperate with the first and second connecting portions 27a and 27b associated with the lower plate 19 of the intermediate heat exchange module 15c, the first and second connecting portions 27a and 27b of the upper plate 17 of the intermediate heat exchange module 15c cooperate with the connecting portions 27a and 27b associated with the lower plate 19 of the upper heat exchange module 15b, and the second connecting portion 27b of the upper plate 17 of the module higher heat exchange 15b cooperates with the junction portion 27 associated lid 3b.

In addition, the first and second connection portions 27a and 27b of the heat exchange modules 15 thus have holes or holes for the passage of the first fluid HP. Thus, the first connecting portions 27a communicate with each other and with the first inlet port 7 of the first fluid HP. An input channel of the first HP fluid is thus defined.

Similarly, the second connection portions 27b communicate with each other and with the second outlet port 13 of the first HP fluid. An output channel of the first HP fluid is thus defined.

Of course, the junction portions 27, the first and second connecting portions 27a and 27b cooperate with each other, for example by brazing, in a sealed manner in order to prevent any leakage.

In addition, to promote the circulation of the first fluid HP in the first channels before its evacuation, the first connecting portions 27a and the second connecting portions 27b of the upper plate 17, respectively the lower plate 19, can be arranged on each side. other of the upper plate 17, respectively the lower plate 19, on a common diagonal of the relevant plate, shown in dashed lines in FIG. 3. Other circuits, not shown, are, of course, conceivable in the context of FIG. the present invention.

In addition, in order to improve the flow of the first fluid HP, it is also possible for the first and second connecting portions 27a and 27b to form recesses on the internal surfaces 29 opposite the top plate 17 and the lower plate 19.

On the other hand, in the example illustrated in FIGS. 1 and 2, the joining portion 27 of the housing body 3a forms a boss inwardly of the surface of the housing body 3a facing the module of the housing. lower heat exchange 15a. Similarly, the junction portion 27 of the cover 3b forms a boss inwardly of the surface of the lid 3b vis-à-vis the upper heat exchange module 15b. And, the connecting portions 27a and 27b of the heat exchange modules 15 form bosses on the outer surfaces 31 of the upper plates 17 and lower plates 19.

The bosses formed extend respectively towards the junction portions 27 and the associated first and second connecting portions 27a or 27b. Thus, when the heat exchange modules 15 are assembled in the housing 3, the bosses of the portions of junction 27, and first and second connecting portions 27a and 27b make it possible to define circulation spaces 33 between one or more consecutive heat exchange modules 15c and between the lower heat exchange module 15a, respectively the exchange module upper thermal 15b, and the bottom of the housing body 3a, respectively the lid 3b.

The circulation spaces 33 thus delimited form second circulation channels of the second fluid BP. Preferably, the second circulation channels are parallel to each other with a height that can be between 2 mm and 4.8 mm. In this embodiment according to Figures 1 and 2, the heat exchanger 1 has four second circulation channels.

The second circulation channels are thus located above and below the first circulation channels to optimize the heat exchange between the first fluid HP and the second fluid BP.

Thus, with a reduced number of heat exchange modules 15, of which there are three according to the example presented, several first and second circulation channels are obtained, here three first circulation channels and four second circulation channels. This limits the production costs and the size of the heat exchanger 1.

In addition, second fins 35, arranged in the circulation spaces 33 can be provided in order to increase the heat exchange area and the thermal performance. The second fins 35 can be obtained by various processes such as stamping, extrusion, rolling, etc. For greater clarity, the second fins 35 are not shown on section A-A of FIG.

In addition, the second circulation channels are also parallel to the first circulation channels so that the first fluid HP and the second fluid BP flow in two parallel directions. In a particularly advantageous manner, regardless of the circuitry of the first fluid HP and the second fluid BP, the first fluid HP always flows in a direction parallel to and opposite the direction of flow of the second fluid BP.

In the heat exchanger 1 illustrated in FIGS. 1 and 2, the second inlet orifice 11 of the second fluid BP being at the level of the second outlet orifice 13 of the first fluid HP and the first outlet orifice 9 of the second fluid BP being at the first inlet orifice 7 of the first fluid HP, the first fluid HP and the second fluid BP circulate against the current. The countercurrent circulation makes it possible to reduce the temperature differences at the outlet of the heat exchanger 1 and thus to further optimize the performance of the heat exchanger 1.

Of course, the circulation of the first fluid HP and the second fluid BP can be done in the same direction, for a cocurrent circulation.

In order to improve the maintenance of the various heat exchange modules 15, additional holding portions 37, shown in FIGS. 1 and 3, can be provided on the upper plates 17 and the lower plates 19. For example, the portions Additional holding means 37 are arranged adjacent the first connecting portions 27a and / or the second connecting portions 27b with the same hollow characteristics on the inner surfaces 29 and bosses on the outer surfaces 31 of the upper plates 17 and plates. lower 19 and with a smaller size 13 than the first and second connecting portions 27a and 27b.

The additional holding portions 37 have an additional function in that they prohibit any movement of the second fins 35 present in the circulation spaces 33.

The thermal exchange performance is thus improved by keeping a relatively simple shape of the upper plates 17 and the lower plates 19 forming the heat exchange modules 15.

According to a second alternative embodiment shown in FIG. 4, the heat exchanger 1 differs from the first embodiment previously described in that the housing 3 is made in the form of two half-housings 15 3 'and 3 " .

According to this second embodiment, each half-casing 3 'and 3 "respectively in contact with the lower heat exchange modules 15a and the upper heat exchange modules 15b, comprises a junction portion 27. The modules of FIG. heat exchange 15 remain identical with respect to the first embodiment previously described.

With regard to the assembly method, the two half-housings 3 'and 3 "are fixed, for example by soldering, at a junction 41 between the two half-housings 3' and 3" to guarantee the tightness of the housing 3.

Finally, such a heat exchanger 1 is particularly suitable for use within an air conditioning loop for a motor vehicle comprising a gas condenser or cooler, an expansion member, an evaporator and a compressor traversed in this order by a fluid. refrigerant. The air conditioning loop comprises a high pressure branch, starting at the compressor outlet and terminating at the inlet of the expansion member, and a low pressure branch, starting at the outlet of the expansion member and ending at the inlet of the compressor. In this case, the heat exchanger 1 according to the invention is used as an internal heat exchanger, that is to say a heat exchanger traversed by the high-pressure refrigerant fluid and high temperature, circulating in the first channels, and traversed by the same refrigerant fluid at low pressure and low temperature, flowing in the second channels.

Figure 5 is a cross sectional view, in a plane similar to the plane B-B of Figure 1, of a heat exchanger 1 according to the present invention. According to FIG. 5, the heat exchanger 1 does not include a housing 3 that houses a plurality of heat exchange modules 15.

According to the alternative embodiment of FIG. 5, the heat exchanger 1 comprises four superimposed heat exchange modules 15. According to this variant, the first inner cavities 21 and the circulation spaces 33 are constituted by interstitial zones between upper plates 17 and consecutive lower plates 19. For this purpose, the upper plates 17 and the lower plates 19 comprise recesses oriented towards the first inner cavities 21 in order to define the circulation spaces 33.

According to the various embodiments, the heat exchanger 1 has different dimensional sizes which will now be detailed. According to the present invention, the heat exchanger 1 has a height H 1, H x defined as the distance between the lower plate 19 of the lower heat exchange module 15a and the upper plate 17 of the upper heat exchange module 15b. In addition, the heat exchanger 1 has a width W 1, H x defined as the width of the bottom plate 19 or the top plate 17 of the upper heat exchange modules 15a, 15b or 15c.

The first fins 25 disposed in the first inner cavities 21 for the circulation of the first fluid HP are of height H, FHP defined being the distance between the lower plate 19 and the upper plate 17 of the heat exchange module 15a, 15b or 15c, taken from the first inner cavity 21. The first fins 25 have a width W, FHP defined as the extension width of the first fins 25 in the first inner cavity 21. Finally, in the case where the first fins 25 are made from a corrugated metal plate, they have a pitch P_HP defined as being the half-distance between two successive peaks of the corrugations forming the first fins 25.

Similarly, the second fins 35 disposed in the circulation spaces 33 for the circulation of the second LP fluid have a height H, FBP defined being the distance between the lower plate 19 and the upper plate 17 of two heat exchange modules 15a. , 15b or 15c successive, taken at the circulation space 33. The second fins 35 have a width W, FBP 20 defined as the extension width of the second fins 35 in the circulation space 33. Finally, in the case where the second fins 35 are made from a corrugated metal plate, they have a pitch P_BP defined as the half distance between two successive peaks of the corrugations forming the second fins 35. Preferably, the first fins 25 and the second fins 35 are made from aluminum or an aluminum alloy. Particularly advantageously, the first fins 25 and second fins 35 have a thickness of between 0.07 mm and 0.15 mm, preferably 0.10 mm.

Advantageously, the width W, FHP of the first fins 25 and the width W, FBP of the second fins 35 are between 45.0 mm and 70.0 mm. The following relationships are then obtained: 45.0 mm <_W, FBP <_70.0mm 45.0 mm <_ W, FHP <70.0 mm

Furthermore, the height H 2, FHP of the first fins 25 is between 1.0 mm and 1.5 mm and the height H 2, FBP of the second fins 35 is between 2.0 mm and 4.8 mm. We then have the following relations: 2.0 mm5H_IFBP <_4.8mm 1.0 mm <_H, FHP <_1.5mm

In addition, the pitch P_, FHP of the first fins 25 is between 0.9 mm and 1.5 15 mm, preferably 1.0 mm, and the pitch P_, FBP of the second fins 35 is between 1.3 mm and 1.8 mm, preferably 1.4 mm. We then have the following relations: 1.3 mm <_P, FBP <_1.8mm 0.9 mm <_P, FHP <_1.5mm Such dimensions make it possible to promote the heat exchange between the first fluid HP and the second fluid BP, while limiting the losses of loads.

In addition, advantageously, the upper plate 17 and the lower plate 19 25 of each heat exchange module 15 have a thickness of between 0.5 mm and 1.5 mm, preferably 1.0 mm.

If the heat exchanger 1 has a housing 3, in order to promote the resistance of the heat exchanger 1, the housing body 3a and the cover 3b, or the two half-housings 3 'and 3 ", have a thickness between 1.0 mm and 2.0 20 mm, preferably 1.5 mm.

Referring now to Figures 6 to 9 which show graphs showing the evolution of the thermal efficiency and / or loss of charges of the heat exchanger 1 according to the dimensional parameters of the fins.

More particularly, FIG. 6 shows the evolution of the heat efficiency of the heat exchanger 1 as a function of a length L_IFHp of the first fins 25 and / or a length L_IFBp of the second fins 35.

As shown in FIG. 6, the thermal efficiency of the heat exchanger 1 is set between 35% and 62% in order to meet the requirements related to the use of various refrigerants, especially subcritical coolants such as that the refrigerants known under the name R134A or 1234yf.

Thus, it appears that the optimum thermal efficiency is obtained for a length L_IFHp of the first fins 25 and / or a L_IFBP length of the second fins 35 between 50 mm and 130 mm. In particular, such a thermal efficiency of the heat exchanger 1 is obtained in a heat exchanger arrangement 1 in which: the width W_IFHP of the first fins 25 and the width W_IFBp of the second fins 35 substantially equal to 55 mm, The height H_IFHP of the first fins 25 substantially equal to 1.2 mm, the height H_IFBP of the second fins 35 substantially equal to 3.6 mm, the pitch P_IFHp of the first fins 25 substantially equal to 1.0 mm, and the pitch P_IFBp of the second fins. fins 35 substantially equal to 1.4 mm. According to a particular embodiment, the number of heat exchange modules 15 of the heat exchanger 1 is equal to seven.

FIG. 7 presents the evolution of the thermal efficiency, represented in solid line, and presents the evolution of the loss of charge, represented in dotted lines, of the heat exchanger 1 as a function of the pitch P_IFBP of the second fins 35.

As shown in FIG. 7, the thermal efficiency of the heat exchanger 1 is set between 55% and 62% in order to meet the increased requirements related to the use of certain refrigerant fluids, notably the known subcritical refrigerant fluid. under the name 1234yf. Similarly, the maximum pressure drop of the heat exchanger 1 is set to 100%.

Thus, it appears that the optimum thermal efficiency, for a pressure drop not exceeding 100%, is obtained for a P_IFBP pitch of the second fins 35 between 1.3 mm and 1.8 mm.

In particular, such a thermal efficiency of the heat exchanger 1 is obtained in a heat exchanger arrangement 1 in which: • the length L_IFHP of the first fins 25 and / or the length L_IFBP of the second fins 35 substantially equal to 130 mm, • the width W IFHP of the first fins 25 and the width W_IFBP of the second fins 35 substantially equal to 55 mm, • the height H_ IFHP of the first fins 25 substantially equal to 1.2 mm, • the height H_IFBP of the second fins 35 substantially equal to 3.6 mm, and pitch P_IFHP of the first fins 25 substantially equal to 1.0 mm. According to a particular embodiment, the number of heat exchange modules 15 of the heat exchanger 1 is equal to seven.

FIG. 8 shows the evolution of the thermal efficiency, represented in solid lines, and presents the evolution of the loss of charge, represented in dotted lines, of the heat exchanger 1 as a function of the height H, FBp of the second fins 35.

As shown in FIG. 8, the heat efficiency of the heat exchanger 1 is set between 55% and 62% in order to meet the increased requirements related to the use of certain refrigerant fluids, especially the known subcritical coolant under the name 1234yf. Similarly, the maximum pressure drop of the heat exchanger 1 is set to 100%.

Thus, it appears that the optimum thermal efficiency, for a pressure drop of not more than 100%, is obtained for a height H, FBP of the second fins 35 between 2.0 mm and 4.8 mm.

In particular, such thermal efficiency of the heat exchanger 1 is obtained in a heat exchanger arrangement 1 in which: • the length L_, FHp of the first fins 25 and / or the length L_, FBp of the second fins 35 essentially equal to 130 mm, the width W_IFHp of the first fins 25 and the width W_, FBp of the second fins 35 substantially equal to 55 mm, the height H_, FHp of the first fins 25 substantially equal to 1.2 mm, and the pitch P_, FHp of the first fins 25 substantially equal to 1.0 mm.

According to a particular embodiment, the number of heat exchange modules 15 of the heat exchanger 1 is equal to seven. Finally, FIG. 9 shows the evolution of the thermal efficiency, represented in solid lines, and shows the evolution of the loss of charge, represented in dotted lines, of the heat exchanger 1 as a function of the width W, FBP of the second fins 35.

As shown in FIG. 9, the thermal efficiency of the heat exchanger 1 is set between 60% and 62% in order to meet the increased requirements associated with the use of certain refrigerant fluids, especially the known subcritical refrigerant fluid. under the name 1234yf. Similarly, the maximum pressure drop of the heat exchanger 1 is set to 100%.

Thus, it appears that the optimum thermal efficiency, for a loss of load not exceeding 100%, is obtained for a width W_, FBP of the second fins 35 between 45 mm and 70 mm.

In particular, such a thermal efficiency of the heat exchanger 1 is obtained in a heat exchanger arrangement 1 in which: • the length L_, FHP of the first fins 25 and / or the length L_, FBP of the second fins 35 essentially equal to 130 mm, • the height H_, FHP of the first fins 25 substantially equal to 1.2 mm, • the height H_, FBP of the second fins 35 substantially equal to 3.6 mm • the pitch P_, FHP of the first fins 25 substantially equal to 1.0 mm, and the pitch P_, FBP of the second fins 35 substantially equal to 1.4 mm. According to a particular embodiment, the number of heat exchange modules 15 of the heat exchanger 1 is equal to seven.

Finally, it should be noted that various implementations can be carried out according to the principles of the invention. It should be understood, however, that these examples are given by way of illustration of the object of the invention. Of course, the invention is not limited to these embodiments described above and provided solely by way of example. It encompasses various alternatives and alternatives that may be contemplated by those skilled in the art within the scope of the present invention, including any combinations of detailed value ranges.

Claims (10)

Revendications1. Heat exchanger (1) between a first fluid (HP) and a second fluid (BP), comprising a plurality of thermal modules (15, 15a, 15b, 15c) constituted respectively of an upper plate (17) and a plate lower part (19) by defining between them, a first internal cavity (21) forming a first circulation channel for the first fluid (HP) and at least one circulation space (33) defined between two thermal modules (15, 15a, 15b, 15c) consecutive, characterized in that the circulation space (33) comprises fins (35), said second fins (35), length (L_, FBP) between 50 mm and 130 mm. 2. Heat exchanger (1) according to claim 1, wherein the second fins (35) have a height (H_, FBP) between 2.0 mm and 4.8 mm. 3. Heat exchanger (1) according to claim 1 or 2, wherein the second fins (35) have a pitch (PJFBp) of between 1.3 mm and 1.8 mm, preferably 1.4 mm. 4. Heat exchanger (1) according to one of the preceding claims, wherein the first inner cavity (21) comprises fins (25), said first fins (25), length (L_IFHp) between 50 mm and 130 mm . 5. Heat exchanger (1) according to claim 4, wherein the first fins (25) have a height (H_, FBP) of between 1.0 mm and 1.5 mm. 2330 6. Heat exchanger (1) according to claim 4 or 5, wherein the first fins (25) have a pitch (P_, FHP) between 0.9 mm and 1.5 mm, preferably 1.0 mm. 7. heat exchanger (1) according to one of the preceding claims, wherein the first fins (25) and / or the second fins (35) have a width (W_, FHP, W IFBP) between 45.0 mm and 70.0 mm . 8. Heat exchanger (1) according to one of the preceding claims, wherein the upper plate (17) and / or the lower plate (19) of each heat exchange module (15) has a thickness of between 0.5 mm and 1.5 mm, preferably 1.0 mm. 9. Heat exchanger (1) according to one of the preceding claims, wherein the plurality of thermal modules (15, 15a, 15b, 15c) is disposed inside a housing (3, 3a, 3b, 3 ', 3 "). 10. Heat exchanger (1) according to one of the preceding claims, wherein the housing (3, 3a, 3b, 3 ', 3 ") has a thickness of between 1.0 mm and 2.0 mm, preferably 1.5 mm.