HEAT EXCHANGER FOR A MOTOR VEHICLE

Abstract

The invention relates to a heat exchanger (100) for a motor vehicle, comprising a first circuit (110) comprising at least one first group of chambers (75) and one second group of chambers (76) intended to be traversed by a heat transfer fluid, and a second circuit (120) intended to be traversed by a coolant, the heat exchanger (100) being configured to implement an exchange of heat between the heat transfer fluid and the coolant, the heat exchanger (100) comprising at least one component (155) for differentiating the flow of heat transfer fluid circulating in the first group of chambers (75) from the flow of heat transfer fluid circulating in the second group of chambers (76) of the first circuit (110).

Description

The present invention relates to the field of heat exchangers for motor vehicles. It applies for preference, although not exclusively, to the heat exchangers used in the air conditioning circuits of such vehicles.

The present invention more particularly relates to heat exchangers which comprise a first circuit configured to carry a heat-transport liquid and a second circuit configured to carry a refrigerant fluid. More specifically, the present invention relates to such exchangers in which the second circuit comprises at least two successive passes of refrigerant fluid, and in which the first circuit comprises a plurality of chambers split into several groups of chambers. The heat exchanger is then configured to perform an exchange of heat between the heat-transport liquid circulating in at least one of the groups of chambers and the refrigerant fluid circulating in at least one of the passes of the second circuit. What is meant here by a “pass” is distinct regions of the second circuit of the heat exchanger which are configured so that the refrigerant fluid circulates successively within them. According to one particular arrangement, the passes of the second circuit may be arranged in such a way that the refrigerant fluid circulates in parallel between them.

In such exchangers, also known as water-cooled condensers, the refrigerant fluid is admitted to a first pass of the second circuit in gaseous form and then, circulating successively through the various passes of the second circuit, in contact with the various groups of chambers of the first circuit through which chambers the heat-transport liquid circulates, it is progressively condensed until it leaves the exchanger in liquid form.

The technical problem to which the present invention aims to propose a solution is that of the efficiency of the exchange of heat in the various passes of the second circuit, notably in those regions of the heat exchanger in which the physical-chemical conversion that is the condensing of the refrigerant fluid takes place.

In order to increase the efficiency of such a heat exchange, a first subject of the present invention is a heat exchanger for a motor vehicle, comprising:

• • a first circuit through which a heat-transport liquid is intended to pass and which comprises a first inlet header via which the heat-transport liquid is admitted to the first circuit and a first outlet header via which the heat-transport liquid leaves the first circuit, the first circuit comprising a plurality of chambers which are fluidically connected to the first inlet header and to the first outlet header and are split into at least a first group of chambers and a second group of chambers,
  • a second circuit through which a refrigerant fluid is intended to pass and which comprises a second inlet header via which the refrigerant fluid is admitted into the heat exchanger and a second outlet header via which the refrigerant fluid leaves the heat exchanger, the second circuit comprising at least two successive passes, the heat exchanger being configured to perform an exchange of heat between the
    heat-transport liquid circulating in at least one of the groups of chambers and at least one of the passes of the second circuit,
    characterized in that the heat exchanger comprises at least one differentiation member for differentiating the flowrate of heat-transport liquid circulating per chamber in the first group of chambers from the flowrate of heat-transport liquid circulating per chamber in the second group of chambers of the first circuit.

The presence of the aforesaid differentiation member results in different flow velocities for the heat-transport liquid between the groups of chambers concerned. This has the effect of differentiating the duration of the exchange of heat performed between the heat-transport liquid circulating in these groups of chambers and the refrigerant fluid circulating in the corresponding passes of the second circuit. The invention thus achieves its stated objective by notably making it possible to increase a duration of the exchange of heat between the heat-transport liquid circulating in one group of chambers in which the flowrate of this heat-transport liquid is lowest and the refrigerant fluid circulating in a pass of the second circuit in contact with this group of chambers.

According to one particularly advantageous embodiment, each chamber is delimited by at least two plates, each plate comprising a bottom wall surrounded by a turned-up edge, the bottom wall being provided with at least one opening which at least in part delimits the first inlet header, the two plates being positioned one inside the other. Advantageously, the bottom walls of the plates delimiting the chambers of the first circuit have a substantially planar overall shape.

The heat exchanger according to the invention is therefore made up of a stack of plates as previously described stacked in a direction of stacking substantially perpendicular to an overall main plane of extension of the bottom wall of each of these plates. This has the effect that the aforementioned first inlet header is formed of the stack of the aforesaid openings pierced in the bottom walls of the plates delimiting the chambers of the first circuit.

The first inlet header for admitting the heat-transport liquid into the first circuit of the exchanger according to the invention therefore substantially assumes the form of a conduit extending through the heat exchanger according to the invention. According to a preferred although not exclusive embodiment, the openings formed in the bottom walls of the plates that make up the heat exchanger according to the invention are arranged in such a way that the aforesaid first inlet header extends substantially perpendicular to the bottom walls of the plates which delimit the chambers of the first circuit and, therefore, substantially parallel to the direction of stacking of the aforesaid plates.

According to a first example of how the invention may be embodied, the first inlet header comprises a first conduit supplying the first group of chambers and a second conduit supplying the second group of chambers, the differentiation member involving a second bore section of the second conduit that is smaller than a first bore section of the first conduit. What is meant here by a bore section is the surface area of a cross section of the conduit concerned, measured in a plane substantially perpendicular to the main direction of extension thereof. The foregoing therefore means that the flowrate of heat-transport liquid circulating in the second conduit of the first inlet header is smaller than the flowrate of heat-transport liquid circulating in the first conduit of the first inlet header.

Advantageously, according to such an example, a ratio between the second bore section of the second conduit and the first bore section of the first conduit is comprised between 0.4 and 0.8.

More specifically, according to a first embodiment of this first example of how the invention may be embodied, the bottom walls of the at least two plates each comprise at least a first opening and a second opening, respectively constituting the first conduit and the second conduit of the first inlet header.

According to one example of how the invention may be embodied, the second bore section is defined by at least one of the second openings formed in the plate.

To complement this, the aforementioned first bore section and the aforementioned second bore section are respectively defined by the dimensions of at least one of the openings formed in the aforesaid plate or plates. For example, the first bore section is defined by the aforementioned first opening, and the second bore section is defined by the second opening defined hereinabove.

According to the invention, the differentiation member is formed by at least a second opening that forms part of the second conduit.

Alternatively, the differentiation member comprises all of the second openings of the second conduit.

The above-defined differentiation member that differentiates the flowrate of heat-transport liquid is therefore embodied here by the difference in bore section between the first opening and the second opening. In other words again, the differentiation member corresponds to the second bore section of at least one of the second openings being smaller than the first bore section of one of the first openings.

It must therefore be understood here that, in this example of how the heat exchanger according to the invention may be embodied, the differentiation of the flowrate of heat-transport liquid between the first conduit and the second conduit of the first inlet header is the result of the geometry of the plates that forms the first circuit and of the dimensions of the openings made in the bottom walls of these plates.

According to one example, all of the second openings that define the second conduit of the first inlet header may have the same bore section, substantially equal to the aforementioned second bore section. The differentiation member that differentiates the flowrate of heat-transport liquid is then defined by all of the second openings that define the second conduit. In a variant, just one of the second openings that contributes to defining the second conduit has a bore section substantially equal to the aforementioned second bore section.

In another example, the heat exchanger comprises at least one heat-transport-liquid supply unit, the supply unit being fluidically connected to the first inlet header which comprises a first conduit supplying the first group of chambers and a second conduit supplying the second group of chambers. The first conduit and the second conduit therefore together form the above-defined first inlet header. Advantageously, in such an example, the bore sections of the first conduit and of the second conduit are substantially equal.

In this example, the invention anticipates for the supply unit to comprise a first duct supplying the first conduit and a second duct supplying the second conduit of the first inlet header, the differentiation member involving a second bore section of the second duct that is smaller than a first bore section of the first duct. Advantageously, a ratio between the second bore section of the second duct and the first bore section of the first duct is comprised between 0.4 and 0.8.

According to another example, the first heat-transport liquid circuit comprises a third group of chambers which are fluidically connected to the first conduit of the first inlet header and to the first outlet header successively to the first group of chambers, the heat-transport liquid flowrate differentiation member comprising at least a third bore section of the first conduit, positioned between the first group of chambers and the third group of chambers, the third bore section being smaller than the first bore section of the first conduit. Advantageously, a ratio between the third bore section of the first conduit and the first bore section of the first conduit is substantially comprised between 0.4 and 0.8.

In other words, according to this example, the bore section of the first conduit according to the invention is reduced in the third group of chambers of the first circuit. This makes it possible to increase still further the residence time of the heat-transport liquid in the third group of chambers of the first circuit and, therefore, the duration and efficiency of the exchange of heat between the refrigerant fluid circulating in the second circuit and the heat-transport liquid circulating in the third group of chambers.

According to one advantageous example, at least one of the first openings that make up the first conduit exhibits the third bore section.

The invention thus makes it possible, through simple means such as the creation of openings of different dimensions in plates delimiting the chambers of the first circuit of a heat exchanger as has just been described, to modify the flowrate of heat-transport liquid within such an exchanger, for an increased residence time in contact with the refrigerant fluid and, therefore, for better heat-exchange efficiency. The invention thus achieves its stated objective.

A second aspect of the invention also relates to a thermal conditioning system for a motor vehicle comprising at least one heat exchanger according to any one of the preceding features. Advantageously, in such a thermal conditioning system, the heat-transport liquid is glycol water.

Further features, details and advantages of the invention will become more clearly apparent from reading the description, which is provided below by way of illustration and with reference to drawings in which:

FIG. 1 is a schematic perspective overview of one example of a thermal conditioning system according to the invention;

FIG. 2 is a schematic view in section on a vertical and transverse plane of the heat exchanger of FIG. 1 showing a first example of how the invention may be embodied;

FIG. 3 is a schematic view in section on a vertical and transverse plane of the heat exchanger of FIG. 1 showing a second example of how the invention may be embodied;

FIG. 4 is a schematic view in section on a vertical and transverse plane of the heat exchanger of FIG. 1 showing a third example of how the invention may be embodied.

It should first of all be noted that although the figures set out the invention in detail for implementing the invention, these figures may of course be used in order to better define the invention if necessary. It should also be noted that these figures set out only a number of examples of ways in which the invention may be embodied.

FIG. 1 is a schematic perspective illustration of a thermal conditioning system 500 according to the invention.

Such a thermal conditioning system 500 notably comprises a heat exchanger 100 configured to be the site of an exchange of heat between a heat-transport liquid and a refrigerant fluid both circulating within it. According to one example, the heat-transport liquid is a glycol water. The heat-transport liquid and the refrigerant fluid are not depicted in the figures.

Advantageously, the heat exchanger 100 comprises a first circuit 110 through which the heat-transport liquid is conveyed, and a second circuit 120 through which the refrigerant fluid is conveyed, the first circuit 110 and the second circuit 120 being, inside the heat exchanger 100, in contact with one another in such a way that an exchange of heat between the heat-transport liquid and the refrigerant fluid can occur.

The first circuit 110 of the heat exchanger 100 extends between a first inlet header 1 via which the heat-transport liquid is admitted to the first circuit 110 of the heat exchanger 100 and a first outlet header 2 via which the heat-transport liquid leaves the first circuit 110 of the heat exchanger 100.

The second circuit 120 of the heat exchanger 100 extends between a second inlet header 3 via which the refrigerant fluid is admitted to the second circuit 120 of the heat exchanger 100 and a second outlet header 4 via which the refrigerant fluid leaves the second circuit 120 of the heat exchanger 100.

According to the example more particularly illustrated in FIG. 1, the heat exchanger 100 comprises a supply unit 5 via which the heat-transport liquid enters the above-defined first inlet header 1. The supply unit 5 is therefore fluidically connected to the first inlet header 1. According to this example, the heat exchanger 100 also comprises an outlet unit 50 fluidically connected to the first outlet header 2 and via which the heat-transport liquid leaves the heat exchanger 100.

The refrigerant fluid, admitted to the heat exchanger 100 in essentially gaseous form, is progressively condensed as it passes through the heat exchanger 100 through an exchange of heat with the heat-transport liquid, until it leaves the heat exchanger 100 in essentially liquid form. In one particularly advantageous configuration, the refrigerant fluid in liquid form is received and stored in a condensation bottle 200 arranged near the heat exchanger 100. Advantageously, and to increase the efficiency of the exchange of heat between the heat-transport liquid and the refrigerant fluid, the latter makes a plurality of passes through the second circuit 120, successively in contact with different regions of the first circuit 110. The various distinct regions of the second circuit 120, through which regions the refrigerant fluid successively circulates will, in what follows, be referred to by the term “passes” of the second circuit 120 of the heat exchanger 100.

FIG. 2 schematically illustrates, in section on a vertical and transverse plane A visible in FIG. 1, a heat exchanger 100 according to a first example of how the invention may be embodied.

FIG. 2 again shows the above-defined first inlet header 1, configured to admit the heat-transport liquid into the first circuit 110 of the heat exchanger 100. This FIG. 2 also again shows the supply unit 5 as previously defined, configured to allow the heat-transport liquid to enter the first circuit 110.

With reference to FIG. 2, the heat exchanger 100 is formed of a stack of N plates 6a, . . . 6i, 6j, . . . 6n, stacked in a direction of stacking E arbitrarily referred to in what follows as the vertical direction V of the heat exchanger 100 and indicated by the axis V in FIG. 2. It should be noted that the vertical direction V of the heat exchanger 100 can be anything with reference to a vertical direction of a motor vehicle in which a thermal conditioning system as previously described and comprising the heat exchanger 100 is placed.

As shown in FIG. 2, each plate 6a, . . . , 6i, 6j, . . . 6n, of the heat exchanger 100 is formed of a bottom wall 60a, . . . , 60i, 60j, . . . 60n the overall shape of which is substantially planar, surrounded by a turned-up edge 61a, . . . 61i, 61j, . . . 61n, of which the dimensions, measured perpendicular to the main plane of extension of the bottom wall 60a, . . . , 60i, 60j, . . . , 60n, are small relative to the dimensions of this wall. Only two plates 6i, 6j, their bottom walls 60i, 60j, and their turned-up edges 61i, 61j, have been identified in FIG. 2. According to the example illustrated in FIG. 2, the bottom walls 60a, . . . , 60i, 60j, . . . 60n are substantially perpendicular to the above-defined vertical direction V of the heat exchanger 100, and are substantially parallel to a plane P defined by a longitudinal direction L and a transverse direction T, which are respectively arbitrarily referred to as the longitudinal direction and as the transverse direction of the heat exchanger 100.

In the heat exchanger 100 according to the invention, the plates 6a, . . . , 6i, 6j, . . . 6n pairwise delimit chambers 7a, . . . 7i, 7j, . . . , 7n of the first circuit 110 of the heat exchanger 100, which is to say chambers configured to convey the heat-transport liquid within the heat exchanger 100. Only one chamber 7i, delimited by the plates 6i, 6j, is depicted in FIG. 2. The spaces defined between the chambers 7a, . . . , 7i, 7j, . . . , 7n together partially form the second circuit of the heat exchanger 100, in which circuit the refrigerant fluid circulates in contact with the chambers 7a, . . . , 7i, 7j, . . . , 71n of the first circuit 110. It must be appreciated here that the bottom walls 60a, . . . , 60i, 60j, . . . , 60n, of substantially planar overall shape, have reliefs so that when the corresponding plates 6a, . . . , 6i, 6j, . . . , 6n are stacked in the aforementioned vertical direction V, these walls between them form different volumes respectively corresponding at least in part to the second circuit 120 of the heat exchanger 100 or to chambers 7a, . . . , 7i, 7j, . . . , 7n of the first circuit 110.

Advantageously, each bottom wall 60a, . . . , 60i, 60j, . . . , 60n comprises at least one opening 62a, . . . , 62i, 62j, . . . , 62n which at least partly delimits the first inlet header 1. The first inlet header 1 of the first circuit 110 thus extends substantially over the entirety of the dimension of the heat exchanger 100 in the above-defined vertical direction V thereof, and is formed of the stack of the aforesaid openings 62a, . . . , 62i, 62j, . . . , 62n.

Advantageously, the chambers 7a, . . . , 7i, 7j, . . . , 7n of the first circuit 110 are organized into mutually independent groups of chambers, through which groups the heat-transport liquid circulates successively. For example, the chambers 7a, . . . , 7i, 7j, . . . , 7n of the first circuit 110 are organized into a first group of chambers 75 and a second group of chambers 76, each group of chambers 75, 76 being, within the heat exchanger 100, in contact with a pass, as defined hereinabove, of the second circuit 120 of the heat exchanger 100. In other words, the first group of chambers 75 is in contact with a first pass, not depicted, of the second circuit 120, and the second group of chambers 76 is in contact with a second pass, not depicted, of the second circuit 120 and distinct from the first pass. The first group of chambers 75 and the second group of chambers 76 are indicated schematically in FIG. 2.

According to the first example of how the invention may be embodied, which is illustrated in FIG. 2, the inlet header 1 comprises a first conduit 10 and a second conduit 11.

As shown by FIG. 2, the first conduit 10 extends substantially over the entirety of the dimension of the heat exchanger 100 in the above-defined vertical direction V thereof. According to the invention, the second conduit 11 extends substantially over half of the dimension of the heat exchanger 100 in the vertical direction V thereof. Moreover, as shown in FIG. 2, the first conduit 10 is formed of the stack, in the vertical direction V of the heat exchanger 100, of first openings 63a, . . . , 63i, 63j, . . . , 63n, arranged in the plates 6a, . . . , 6i, 6j, . . . , 6n, of the heat exchanger 100, and the second conduit 11 is formed of the stack, in the vertical direction V of the heat exchanger 100, of second openings 64a, . . . , 64i, 64j, . . . , 64n, arranged in the plates 6a, . . . , 6i, 6j, . . . , 6n, of the heat exchanger 100.

In other words, according to the example illustrated in FIG. 2, the bottom wall 60a, . . . , 60i, 60j, . . . , 60n, of each plate 6a, . . . , 6i, 6j, . . . , 6n, that makes up the heat exchanger 100, is pierced with at least a first opening 63a, . . . , 63i, 63j, . . . , 63n and with at least a second opening 64a, . . . , 64i, 64j, . . . , 64n, which openings together respectively define the first conduit 10 and the second conduit 11 of the first inlet header 1.

According to the invention, the first conduit 10 of the first inlet header 1 is configured to supply heat-transport liquid to the above-defined first group of chambers 75, and the second conduit 11 of the first inlet header 1 is configured to supply heat-transport liquid to the above-defined second group of chambers 76.

Moreover, the invention plans for a first bore section 150 of the first conduit 10 to be greater than the second bore section 160 of the second conduit 11, the bore section being defined here in a plane substantially perpendicular to the main direction of extension of the conduit concerned. More specifically, the invention plans for a ratio between the second bore section 160 and the first bore section 150 to be comprised between 0.4 and 0.8.

It should be noted that, according to the first example of how the invention may be embodied, illustrated more particularly in FIG. 2, the supply unit 5 comprises, on the one hand, a first duct 50 fluidically connected to the first conduit 10 of the first inlet header 1 and, on the other hand, a second duct 51 fluidically connected to the second conduit 11 of the first inlet header 1.

According to the example more particularly illustrated in FIG. 2, the first conduit 10 and the second conduit 11 each have a substantially cylindrical shape, with the axis of elongation substantially parallel to the above-defined vertical direction V of the heat exchanger 100. According to such an example, the bore sections 150, 160 may be represented by the diameters of the first conduit 10 and of the second conduit 11, respectively, these being measured perpendicular to the vertical direction V of the heat exchanger 100. More generally, the bore sections 150, 160 are to be understood as meaning the surface-areas of a projection of the first conduit 10 and of the second conduit 11 respectively on to a plane perpendicular to the vertical direction V of the heat exchanger 100.

It will be appreciated from the foregoing that the first bore section 150 is defined by at least one of the first openings 63a, . . . , 63i, 63j, . . . , 63n of the first conduit 10 and that the second bore section 160 as defined by at least one of the second openings 64a, . . . , 64i, 64j, . . . , 64n formed in the plate 6a, . . . , 6i, 6j, . . . , 6n.

It then follows from the foregoing that, in the thermal system 500 according to the invention, as illustrated in FIG. 1, the flowrate of heat-transport liquid circulating in the second conduit 11 is lower than the flowrate of heat-transport liquid circulating in the first conduit 10. The above-defined second bore section 160, which is smaller than the first bore section 150, therefore forms a differentiating member 155 differentiating the flowrate of heat-transport liquid within the heat exchanger 100.

Stated differently, the flowrate differentiating member 155 that differentiates the flowrate of the heat-transport liquid is formed here by at least one of the second openings 64a, . . . , 64i, 64j, . . . , 64n contributing to defining the second conduit 11 of the first inlet header 1, which has the second bore section 160 smaller than the first bore section 150 of the first conduit 10 of the first inlet header 1.

It will be appreciated from the foregoing that the differentiating member 155 is formed by one of the second openings 64a, . . . , 64i, 64j, . . . , 64n of the second conduit 11. Alternatively, the differentiating member may be defined by all of the second openings 64a, . . . , 64i, 64j, . . . , 64n of the second conduit 11.

Because of the presence of this differentiating member 155, the residence time that the heat-transport liquid spends in the second group of chambers 76, which is supplied with heat-transport liquid by the second conduit 11, is longer than the residence time that the heat-transport liquid spends in the first group of chambers 75 which is supplied with heat-transport liquid by the first conduit 10. The duration of the exchange of heat between the heat-transport liquid circulating in the second group of chambers 76 and the refrigerant fluid is therefore longer than the duration of the exchange of heat between the heat-transport liquid circulating in the first group of chambers 75 and the refrigerant fluid. This then results in greater effectiveness of the exchange of heat that takes place between the heat-transport liquid circulating in the second group of chambers 76 and the refrigerant fluid circulating in the pass, as defined hereinabove, that is in contact with the second group of chambers 76 in the heat exchanger 100.

FIG. 3 schematically illustrates, in section on the vertical and transverse plane A visible in FIG. 1, a second example of how a heat exchanger 100 according to the invention may be embodied.

This figure again shows the heat exchanger 100, the first inlet header 1 and the first conduit 10 and second conduit 11 of the first inlet header 1. This FIG. 3 also again shows two plates 6i, 6j of the heat exchanger 100 and a chamber 7i of the first circuit 110 of the exchanger 100, which chamber is delimited by the aforesaid plates 6i, 6j. As in the example illustrated in FIG. 2, the second bore section 160 of the second conduit 11 is smaller than the first bore section 150 of the first conduit 10. Likewise, in the same way as in the example illustrated by FIG. 2, the heat exchanger 100 comprises the supply unit 5, which comprises the first duct 50 fluidically connected to the first conduit 10 of the first inlet header 1, and the second duct 51 fluidically connected to the second conduit 11 of the first inlet header 1.

In the variant illustrated by FIG. 3, at least one of the first openings 63i′, 63j′ that contribute to defining, in the plates 6a, . . . , 6i, 6j, . . . , 6n, the first conduit 10, has a third bore section 170 smaller than the first bore section 150 of the first conduit 10.

In other words, in this variant, the first conduit 10 of the first inlet header 1 comprises a first portion 10a of which a bore section is substantially equal to the aforementioned first bore section 150, and a second portion 10b of which a bore section is smaller than the aforesaid first bore section 150 and substantially equal, to within the manufacturing tolerances, to the aforementioned third bore section 170. According to the invention, a ratio between the bore section 170 and the first bore section 150 is comprised between 0.4 and 0.8.

According to various embodiments of the invention, just one or several of the plates 6a, . . . , 6i, 6j, . . . , 6n that form the second portion 10b of the first conduit 10 has a first opening 63i′, 63j′ of which the bore section is substantially equal to the aforementioned third bore section 170. In other words, according to various embodiments of the invention, just one of the first openings 63i′, 63j′ arranged in the plates 6a, . . . , 6i, 6j, . . . , 6n that form the second portion 10b of the first conduit 10 has a bore section equal to the third bore section 170, or several, or even all, of the first openings 63i′, 63j′ arranged in the plates 6a, . . . , 6i, 6j, . . . , 6n that form the second portion 10b of the first conduit 10 have a bore section equal to the third bore section 170.

Advantageously, the chambers 7i, . . . , 7n delimited by the plates 6i, . . . , 6n in which the first opening or openings 63i′, 63j′ having the third bore section 170 are arranged together form a third group of chambers 77 of the first circuit 110 of the heat exchanger 100, which group finds itself in contact, in the heat exchanger 100, with a third pass of the second circuit 120 of this heat exchanger. It will then be appreciated that the first circuit 110 comprises the third group of chambers 77 which is fluidically connected to the first conduit 10 of the first inlet header 1, successively with the first group of chambers 75, and that the third bore section 170 of the first conduit 10, which bore section is located between the first group of chambers 75 and the third group of chambers 77, forms part of the above-defined differentiating member 155.

It then follows from the foregoing that, within the thermal system, the flowrate of heat-transport liquid circulating in the second group of chambers 76, and the flowrate of heat-transport liquid circulating in the third group of chambers 77, are reduced in comparison with the flowrate of heat-transport liquid circulating in the first group of chambers 75.

In one example, the invention may make provision, on the one hand, for the first group of chambers 75 of the first circuit 110 of the heat exchanger 100 to be in contact with a first pass of the second circuit 120, in which pass the refrigerant fluid circulates in essentially gaseous form and, on the other hand, for the second group of chambers 76 of the first circuit 110 of the heat exchanger 100 to be in contact with a second pass of the second circuit 120, in which pass the refrigerant fluid passes in the liquid state, and for the third group of chambers 77 of the first circuit 110 of the heat exchanger 100 to be in contact with a third pass of the second circuit 120, in which pass the refrigerant fluid circulates in liquid form and is supercooled by the heat-transport liquid, the temperature of the refrigerant fluid in the liquid state being lowered below its saturation temperature.

FIG. 4 schematically illustrates, in section on the vertical and transverse plane A visible in FIG. 1, a third example of how the invention may be embodied. This figure more specifically illustrates the above-defined supply unit 5 of the heat exchanger 100 according to the invention, as well as the above-described first duct 50 and second duct 51 of this supply unit 5.

According to the example more particularly illustrated by FIG. 4, the invention makes provision for the above-defined differentiating member 155 to be formed on the first duct 50 fluidically connected to the first conduit 10 of the first inlet header 1, and by the second duct 51 of the supply unit 5 fluidically connected to the second conduit 11 of the first inlet header 1.

More specifically, according to this example, the invention makes provision for the first duct 50 of the supply unit 5 to have a first bore section 500, and for the second duct 51 to have a second bore section 510, the first bore section 500 of the first duct 50 being greater than the second bore section 500 of the second duct 51. A ratio between the second bore section 500 of the second duct 51 and the first bore section 500 of the first duct 50 is comprised between 0.4 and 0.8.

It will be appreciated here that the differentiating member 155 is formed by the second bore section 160 of the second duct 51 being smaller than the first bore section 500 of the first duct 50. The differentiating member is therefore indeed here supported by the supply unit 5 rather than, as in the preceding examples, being arranged actually within the openings 62a, . . . , 62i, 62j, . . . 62n of the plates 6a, . . . , 6i, 6j, . . . 6n.

Such an arrangement offers an advantage in terms of cost, in so far as the advantages of the invention can be combined with a standardization of all of the plates 6a, . . . , 6i, 6j, . . . 6n that form the heat exchanger 100. Specifically, there is then no longer any need to differentiate the manufacture of the various sets of plates having different openings delimiting the different conduits of the first inlet header 1, since the differentiating of flowrate between the aforesaid conduits is performed upstream of the heat exchange zone, as the heat-transport liquid enters the inlet header 1 made up of the above-described conduits 10, 11. Such an arrangement furthermore reduces the risks of errors of assembly during the stacking of the various sets of plates 6a, . . . , 6i, 6j, . . . 6n having openings 63a, . . . , 63i, 63j, . . . , 63n, 64a, . . . , 64i, 64j, . . . , 64n of which the geometric characteristics differ according to whether they are intended to delimit the aforementioned first conduit 10 or the aforementioned second conduit 11 of the first circuit 110.

Whatever the variant considered, the invention makes it possible, using simple means, to differentiate the flowrate of heat-transport liquid between various regions of the first circuit 110 of the heat exchanger 100, so as to differentiate the duration of the exchange of heat performed between this heat-transport liquid and the refrigerant fluid circulating in the second circuit 120 of the heat exchanger 100 and thus increase the efficiency of this exchange in predefined regions of the heat exchanger 100.

It should be noted that this differentiation of the flowrate of the heat-transport liquid within the heat exchanger 100 of a thermal system 500 like the one illustrated in FIG. 1 is the result solely of the geometry of the plates 6a, . . . , 6i, 6j, . . . , 6n which make up the heat exchanger 100 and, notably, of the dimensions of the openings which, pierced in these plates, delimit therein the first inlet header 1 via which the heat-transport liquid is admitted to the first circuit 110 of the heat exchanger 100.

According to one method of manufacture in which the plates 6a, . . . , 6i, 6j, . . . , 6n are, for example, produced by pressing a thin sheet, implementation of the invention therefore proves to be extremely simple and very low in cost insofar as it requires nothing more than a change to the dimensions of one or more of the openings made in these plates in order to delimit the first inlet header 1.

The invention as has just been described nevertheless is not limited to the exclusively described and illustrated means and configurations, and is also applicable to all equivalent means or configurations and to any combination of such means or configurations.

Claims

1. A heat exchanger for a motor vehicle comprising:

a first circuit through which a heat-transport liquid is intended to pass and which comprises a first inlet header via which the heat-transport liquid is admitted to the first circuit and a first outlet header via which the heat-transport liquid leaves the first circuit,

the first circuit comprising a plurality of chambers which are fluidically connected to the first inlet header and to the first outlet header and are split into at least a first group of chambers and a second group of chambers; and

a second circuit through which a refrigerant fluid is configured to pass and which comprises a second inlet header via which the refrigerant fluid is admitted into the heat exchanger and a second outlet header via which the refrigerant fluid leaves the heat exchanger, the second circuit comprising at least two successive passes,

the heat exchanger being configured to perform an exchange of heat between the heat-transport liquid circulating in at least one of the groups of chambers and at least one of the passes of the second circuit,

wherein the heat exchanger comprises at least one differentiation member for differentiating the per-chamber flowrate of heat-transport liquid circulating in the first group of chambers from the per-chamber flowrate of heat-transport liquid circulating in the second group of chambers of the first circuit.

2. The heat exchanger as claimed in claim 1, wherein each chamber is delimited by at least two plates, each plate comprising a bottom wall surrounded by a turned-up edge, the bottom wall being provided with at least one opening which at least in part delimits the first inlet header, the two plates being positioned one inside the other.

3. The heat exchanger as claimed in claim 1, wherein the first inlet header comprises a first conduit supplying the first group of chambers and a second conduit supplying the second group of chambers, the differentiation member involving a second bore section of the second conduit that is smaller than a first bore section of the first conduit.

4. The heat exchanger as claimed in claim 3, wherein a ratio between the second bore section of the second conduit and the first bore section of the first conduit is comprised between 0.4 and 0.8.

5. The heat exchanger as claimed in claim 2, wherein the bottom walls of the at least two plates each comprise at least a first opening and a second opening, which respectively make up the first conduit and the second conduit of the first inlet header.

6. The heat exchanger as claimed in claim 4, wherein the differentiation member is formed of at least a second opening that makes up the second conduit.

7. The heat exchanger as claimed in claim 5, wherein the differentiation member comprises all of the second openings of the second conduit.

7. The heat exchanger as claimed in claim 1, comprising at least one heat-transport-liquid supply unit, the supply unit being fluidically connected to the first inlet header which comprises a first conduit supplying the first group of chambers and a second conduit supplying the second group of chambers.

8. The heat exchanger as claimed in claim 7, wherein the supply unit comprises a first duct supplying the first conduit and a second duct supplying the second conduit of the first inlet header, the differentiation member involving a second bore section of the second duct that is smaller than a first bore section of the first duct.

9. The heat exchanger as claimed in claim 3, wherein the first heat-transport liquid circuit comprises a third group of chambers which are fluidically connected to the first conduit of the first inlet header and to the first outlet header successively to the first group of chambers, the heat-transport liquid flowrate differentiation member comprising at least a third bore section of the first conduit, positioned between the first group of chambers and the third group of chambers, the third bore section being smaller than the first bore section of the first conduit.

10. A thermal conditioning system for a motor vehicle comprising at least one heat exchanger as claimed in claim 1.