INTERNAL HEAT EXCHANGER WITH PLATES

Abstract

The invention relates to a heat exchanger with plates of a refrigerant-fluid circuit, the heat exchanger including at least one plurality of plates stacked on top of one another in a vertical stacking direction, the adjacent plates between each other delimiting a plurality of first circulation ducts for the refrigerant fluid in a low-pressure part of the circuit and a plurality of second circulation ducts for the refrigerant fluid in a high-pressure part of the circuit, at least two of the first circulation ducts being adjacent in the vertical direction.

Description

TECHNICAL FIELD

The invention relates to an internal heat exchanger in a refrigerant-fluid circuit of a motor vehicle.

BACKGROUND OF THE INVENTION

Refrigerant-fluid circuits are used to regulate the temperature of an air flow directed toward a motor vehicle passenger compartment and/or to participate in cooling various elements of the vehicle, such as electric storage devices, for example. For this purpose, the refrigerant-fluid circuit incorporates heat exchangers and a compressor and an expansion device that respectively increase and decrease the pressure of the refrigerant fluid as it circulates through the circuit, so that a high-pressure part and a low-pressure part can be distinguished in this circuit.

In such a circuit, the refrigerant fluid entering the compressor must be exclusively in the gaseous state so as not to damage the compressor. For this purpose, it is known to use an accumulation device to recover a persistent liquid fraction from the refrigerant fluid coming out of one of the heat exchangers arranged upstream of the compressor.

To ensure that the refrigerant fluid directed toward the compressor is exclusively in the gaseous state, it is also known to incorporate an internal heat exchanger, which is arranged directly upstream of the compressor and intended to increase the evaporating capacity of the refrigerant fluid. More specifically, the internal heat exchanger is specific to the refrigerant-fluid circuit and is only traversed by the refrigerant fluid, in one direction by the refrigerant fluid circulating in the high-pressure part and in the other direction by the refrigerant fluid circulating in the low-pressure part of the circuit.

Internal heat exchangers are usually in the form of two concentric tubes corresponding respectively to the low-pressure part and the high-pressure part of the circuit with one wall common to each of the two concentric tubes, and the heat exchange required to evaporate the refrigerant fluid from the low-pressure part of the circuit before the refrigerant fluid enters the compressor occurs through the wall common to the two concentric tubes. However, one drawback of such an internal heat exchanger in the form of concentric tubes lies on the one hand in the significant space that it occupies in the vehicle, and on the other hand in the efficiency, which can be improved on account of a significant pressure drop in the tube traversed by the low-pressure refrigerant fluid, thereby limiting the evaporation performance of the refrigerant fluid.

SUMMARY OF THE INVENTION

The invention therefore proposes solving these problems by providing an internal heat exchanger with plates that is able to withstand the high-pressure conditions of the refrigerant-fluid circuit while limiting the pressure drop of the refrigerant fluid in the low-pressure circuit, thereby guaranteeing an optimal evaporating capacity of the low-pressure refrigerant fluid. The specific structure of the internal heat exchanger in the form of plates notably guarantees a space saving compared to structures in the prior art form of concentric tubes. These effects improve overall operation of the refrigerant-fluid circuit.

The invention relates more specifically to a heat exchanger with plates of a refrigerant-fluid circuit, the heat exchanger comprising at least one plurality of plates stacked on top of one another in a vertical stacking direction, the adjacent plates between each other delimiting a plurality of first circulation ducts for the refrigerant fluid in a low-pressure part of the circuit and a plurality of second circulation ducts for the refrigerant fluid in a high-pressure part of the circuit, at least some of the plurality of plates of the heat exchanger comprising a plurality of openings, of which some form a first inlet manifold and others form a first outlet manifold for the low-pressure refrigerant fluid in communication with the first circulation ducts, and of which some form a second inlet manifold and others form a second outlet manifold for the high-pressure refrigerant fluid in communication with the second circulation ducts, the heat exchanger being characterized in that at least two of the first circulation ducts are adjacent in the vertical stacking direction.

The heat exchanger is a plate exchanger formed by a stack of plates configured to delimit refrigerant-fluid circulation ducts between each other, the plates being connected to one another to provide or prevent fluidic communication between the circulation ducts that they participate in delimiting and the manifolds that extend through the plates in the stacking direction. A suitable gap between two adjacent plates creates a refrigerant-fluid circulation duct and the fact that this duct opens into a manifold associated with a low-pressure portion of the circuit or into a manifold associated with a high-pressure portion of the circuit enables this duct to be qualified either as a first low-pressure circulation duct or as a second high-pressure circulation duct.

The heat exchanger is in this case an internal heat exchanger arranged in a refrigerant-fluid circuit upstream of a refrigerant-fluid circuit compressor so as to be traversed only by the refrigerant fluid, in two different directions and at different pressures and temperatures, so that the heat exchange occurs between the refrigerant fluid in a first state and the refrigerant fluid in a second state. The internal heat exchanger is intended, among other functions, to increase the evaporating capacity of the low-pressure refrigerant fluid before it enters the compressor. The internal heat exchanger then enables the low-pressure refrigerant fluid to exchange heat with the high-pressure refrigerant fluid by recovering some of the heat from the latter, thereby changing a persistent liquid fraction in the low-pressure refrigerant fluid to the gaseous state.

The specific arrangement of the circulation ducts inside the internal heat exchanger with plates according to the invention is beneficial as it enables a number of first circulation ducts, associated with the circulation of the low-pressure refrigerant fluid, that is greater than the number of second circulation ducts, associated with the circulation of the high-pressure refrigerant fluid, which makes it possible to limit the pressure drop in the low-pressure refrigerant fluid when it is circulating through the heat exchanger, thereby improving the heat exchanges with the high-pressure refrigerant fluid, in a plate exchanger that is smaller than a concentric-tube exchanger. This improves the evaporating capacity of low-pressure refrigerant fluid in the internal heat exchanger.

According to one feature of the invention, the circulation ducts delimited by the adjacent plates of the plurality of plates are arranged so that a second circulation duct extends on the two sides, in the vertical direction, of the assembly formed by the at least two first adjacent circulation ducts.

According to one feature of the invention, the first circulation ducts are arranged in assemblies of two first circulation ducts that are adjacent in the vertical direction and partially delimited respectively by one and the same plate. In other words, at least one of the plates of the plurality of plates delimits two first adjacent circulation ducts. In this context, three adjacent plates are required to delimit two first adjacent circulation ducts, the plate arranged in the center of the stack of these three adjacent plates, or central plate, being common to the two first adjacent circulation ducts.

According to one feature of the invention, each of the assemblies is separated from another assembly by a single second circulation duct in the vertical direction. All of the first circulation ducts can thus be arranged in assemblies of two first circulation ducts adjacent in the vertical direction, separated by a single second circulation duct, so that the circulation ducts tend to be distributed with a number of first circulation ducts, associated with the circulation of the low-pressure refrigerant fluid, that is equal to or greater than twice the number of second circulation ducts, associated with the circulation of the high-pressure refrigerant fluid.

According to one feature of the invention, each of the plates has peripheral portions surrounding each of the openings, a peripheral portion of a plate potentially being made integral with the peripheral portion of an adjacent plate to isolate the circulation duct delimited between these adjacent plates from the manifold formed by the corresponding openings.

According to one feature of the invention, at the low-pressure refrigerant-fluid manifolds, the plates are distributed into primary plates, with a flat peripheral portion that extends in a plane substantially perpendicular to the vertical stacking direction, and secondary plates in which the peripheral portion is deformed to come into contact with the peripheral portion of a primary plate, the internal heat exchanger with plates being configured so that the plurality of plates includes two successive primary plates at regular intervals.

According to one feature of the invention, the thicknesses of the edges of the peripheral portions participating in delimiting a manifold formed by a plurality of openings differ from one edge to the other in the vertical stacking direction.

According to one feature of the invention, each of the plates comprises at least one exchange surface against which the refrigerant fluid circulates and a raised edge, the plurality of plates being stacked so that all of the raised edges of each of the plates are in contact with each other and that each of the exchange surfaces is at a non-zero distance so as to form the circulation ducts.

According to one feature of the invention, at least one of the exchange surfaces of one of the plates of the plurality of plates comprises a boss.

Irregular profile means a profile that extends outside a main plane of extension of the plate. For example, the irregular profile may be formed by a deformation of the exchange surfaces of the plates such as to disturb the circulation of the refrigerant fluid against the upper and lower faces of the plates. Such a disturbance of the circulation of the refrigerant fluid increases the heat exchanges between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid circulating in the respective circulation ducts thereof.

The invention also relates to a refrigerant-fluid circuit comprising at least one heat exchanger according to any one of the preceding features, the refrigerant-fluid circuit comprising a high-pressure part and a low-pressure part, the heat exchanger being arranged fluidically inside the circuit to enable a heat exchange between the refrigerant fluid circulating in gas form in the low-pressure part with the refrigerant fluid circulating in liquid form in the high-pressure part.

According to one feature of the invention, the first circulation ducts of the heat exchanger are connected to the low-pressure part of the circuit by a first connection block and a second connection block, and the second circulation ducts of the heat exchanger are connected to the high-pressure part of the circuit by a third connection block and a fourth connection block of the heat exchanger.

BRIEF DESCRIPTION OF DRAWINGS

Further features, details and advantages of the invention will become more clearly apparent upon reading the description given below by way of indication with reference to drawings, in which:

FIG. 1 is a schematic view of a part of a refrigerant-fluid circuit;

FIG. 2 is a cross-sectional view of a heat exchanger in the refrigerant-fluid circuit;

FIG. 3 is a perspective view of a stack of plates forming the heat exchanger in FIG. 2; and

FIG. 4 is a schematic view of a detail of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Firstly, it should be noted that while the figures disclose the invention in detail for the implementation thereof, these figures clearly can be used to better define the invention, where appropriate. It also should be noted that these figures merely disclose embodiments of the invention. Lastly, the same reference signs denote the same elements throughout the figures.

FIG. 1 shows a refrigerant-fluid circuit 1 comprising at least one heat exchanger 2 according to the invention, in this case an internal heat exchanger 2. The refrigerant-fluid circuit 1 also comprises at least one compressor 4, a condenser 6, an evaporator 8, and an accumulation device 10. The refrigerant-fluid circuit 1 heats and/or cools a heat-transfer fluid 15, 21 separate from the circuit 1, for example directed towards a passenger compartment of a vehicle, or towards an electric storage device of an electric or hybrid vehicle.

It should be noted that the refrigerant-fluid circuit detailed in the description below is merely an example embodiment, and that said circuit may comprise more elements that are not described herein.

The compressor 4 illustrated schematically in FIG. 1 compresses the refrigerant fluid to increase the pressure, and therefore the temperature, thereof. Therefore, at the outlet of the compressor 4, the high-pressure refrigerant fluid is in the gaseous state and has a high temperature, i.e. greater than the temperature at the inlet of said compressor 4. Therefore, at the outlet of the compressor 4, the refrigerant fluid is circulating in a high-pressure part 12 of the refrigerant-fluid circuit 1.

A first duct 14a extends between the compressor 4 and the condenser 6, which enables a heat exchange between a heat-transfer fluid 15 traversing the condenser and the high-temperature, high-pressure refrigerant fluid, which transfers this heat to said heat-transfer fluid 15. At the outlet of the condenser 6, the refrigerant fluid remains at high pressure, but at a lower temperature than at the inlet of the condenser, such that it is outputted in a two-phase or entirely liquid state.

At the outlet of the condenser 6, the refrigerant fluid is directed to a second duct 14b that extends between said condenser 6 and the internal heat exchanger 2 mentioned above. The internal heat exchanger 2 is configured to be traversed by the refrigerant fluid in two opposing directions, the refrigerant fluid being at high pressure in the first direction and at low pressure in the second direction. The refrigerant fluid in the high-pressure part 12 of the refrigerant-fluid circuit 1 can exchange heat with the refrigerant fluid circulating in a low-pressure part 18 of the refrigerant-fluid circuit 1. This heat exchange improves the performance of the thermodynamic cycle implemented by the refrigerant-fluid circuit 1. The structure of the internal heat exchanger 2 is detailed below in the description.

Having passed through the internal heat exchanger 2, the refrigerant fluid circulates in a third duct 14c which connects said internal heat exchanger 2 to the evaporator 8. More specifically, the third duct 14c comprises at least one expansion device 20 which lowers the pressure and the evaporation point of the high-pressure refrigerant fluid before it enters the evaporator 8. The high-pressure part 12 of the refrigerant-fluid circuit 1 therefore gives way to the aforementioned low-pressure part 18 after the expansion device 20.

At the outlet of the expansion device 20, the refrigerant fluid is at low pressure and circulates inside the evaporator 8 in order to exchange heat with a heat-transfer fluid 21, for example intended to cool an electric storage device (not shown), traversing said evaporator 8. More specifically, this heat-transfer fluid traversing the evaporator 8 transfers its heat to the heat-transfer fluid circulating in the evaporator 8, which therefore evaporates. Thus, the refrigerant fluid evaporates in the evaporator 8 under the effect of the heat captured from the heat-transfer fluid 21, the expansion device 20 having lowered the evaporation point thereof. As a result, at the outlet of the evaporator 8, the refrigerant fluid is primarily in the gaseous state.

At the outlet of the evaporator 8, the refrigerant fluid is directed into a fourth duct 14d leading to the accumulation device 10, in this case an accumulation bottle for example. The accumulation device 10 is intended to collect a persistent liquid fraction of the refrigerant fluid coming out of the evaporator 8. The refrigerant fluid has to pass through the accumulation device 10 in this manner before entering the compressor 4, which can only accept refrigerant fluid in the gaseous state.

At the outlet of the accumulation device 10, the refrigerant fluid enters a fifth duct 14e which directs the fluid towards the aforementioned internal heat exchanger 2 to exchange heat with the refrigerant fluid in the high-pressure part 12 of the aforementioned refrigerant-fluid circuit 1. Entering the internal heat exchanger 2 in this manner guarantees that the refrigerant fluid coming out of said internal heat exchanger 2 is exclusively in the gaseous state before it enters the compressor 4.

The heat exchanger according to the invention is in this context configured to ensure optimal efficiency of the heat exchange and notably the evaporation of the refrigerant fluid when it circulates through the low-pressure part, so as not to damage the compressor 4 arranged downstream of the latter, such damage potentially reducing the operating efficiency of the refrigerant-fluid circuit 1.

Thus, the internal heat exchanger 2 according to the invention is described below in greater detail, notably with reference to FIGS. 2, 3 and 4.

The internal heat exchanger 2 is a plate exchanger including plates 22 stacked on top of one another that is configured to enable refrigerant fluid to circulate in ducts formed between two adjacent plates, the plates being configured to form low-pressure ducts 30, i.e. ducts connected only to the low-pressure part 18 of the circuit, and high-pressure ducts 32, i.e. ducts connected only to the high-pressure part 12 of the circuit. According to the invention, the plates 22 are configured and connected to one another so that the number of low-pressure ducts 30 is greater than the number of high-pressure ducts 32, and notably so that the number of low-pressure ducts is equal to or greater than twice the number of high-pressure ducts.

More specifically, the internal heat exchanger 2 according to the invention comprises a plurality of plates 22 stacked on top of one another in a vertical stacking direction V. Each of these plates 22 is tub-shaped with an exchange surface 24 surrounded peripherally by a raised edge 26. The plates 22 are stacked so that the raised edge 26 of each of the plates 22 is in contact with at least one other raised edge 26 and so that the exchange surface 24 of each of the plates 22 is at a non-zero distance, in the vertical stacking direction V, from the exchange surfaces 24 of the adjacent plates. Refrigerant-fluid circulation ducts 28 are thus formed between two adjacent plates, each of these ducts being configured to communicate fluidically with a fluid inlet and a fluid outlet connected to the high-pressure part or the low-pressure part of the circuit. More specifically, the adjacent plates 22 between each other delimit a plurality of first circulation ducts 30 for the refrigerant fluid in the low-pressure part 18 of the circuit and a plurality of second circulation ducts 32 for the refrigerant fluid in the high-pressure part 12 of the circuit.

At least some of the plurality of plates 22 of the heat exchanger 2 have a plurality of openings 34, some of which are arranged vertically on top of one another to form a plurality of manifolds, as shown notably in FIG. 3. The arrangement of the openings 34 thus defines on the one hand a first inlet manifold 36a and a first outlet manifold 36b for the low-pressure refrigerant fluid, which are intended to communicate fluidically with each of the first circulation ducts 30, and on the other hand a second inlet manifold 38a and a second outlet manifold 38b for the high-pressure refrigerant fluid, which are intended to communicate fluidically with each of the second circulation ducts 32. Each of the manifolds 36a, 36b, 38a, 38b is formed by an alignment of openings and extends vertically through the plurality of plates 22.

One manifold 36a, 36b, 38a, 38b is advantageously formed in each of the corners of the plate heat exchanger, as shown in particular in FIG. 3, it being understood that the two inlet manifolds 36a, 38a may be diagonally opposed, without this meaning that a different arrangement is outside the scope of the invention, provided that, as mentioned above, the number of first circulation ducts inside the exchanger is greater than the number of second circulation ducts. The diagonally opposed arrangement of the inlet manifolds, without limiting the invention, creates inside the internal heat exchanger 2 a crossed circulation of the refrigerant fluid in the first low-pressure circulation ducts 30 and of the refrigerant fluid in the second high-pressure circulation ducts 32, thereby helping to improve the quality of the heat exchanges. Such circulation in alternating directions is notably visible in FIG. 4, where the circulation direction of the refrigerant fluid is shown using arrows, and more specifically first arrows S1 for a first circulation direction in the first circulation ducts 30 and second arrows S2 for a second circulation direction in the second circulation ducts 32.

Furthermore, a first end plate 40 and a second end plate 42 are defined, each arranged at a vertical end of the stack of plates 22. The first end plate 40 then has no openings 34 and therefore helps to vertically close a volume of the heat exchanger 2. Furthermore, in the illustrated example of the invention, the second end plate 42 bears four connection blocks 44a, 44b, 44c, 44d, which are shown schematically in FIG. 1 and are intended to be arranged to face each of the manifolds 36a, 36b, 38a, 38b formed by the openings 34 in the plates 22. In other words, each of the connection blocks 44a, 44b, 44c, 44d is arranged on the second end plate 42 covering the openings 34 formed in the second end plate 42.

The connection blocks 44a, 44b, 44c, 44d therefore provide the fluidic link between the ducts 14b, 14c, 14e, 14f of the refrigerant-fluid circuit 1 described above and the circulation ducts 30, 32 delimited by the plates 22. More specifically, a first connection block 44a fluidically connects the fifth duct 14e to the first circulation ducts 30 via the first inlet manifold 36a, a second connection block 44b connects the first circulation ducts 30 to the sixth duct 14f via the first outlet manifold 36b, a third connection block 44c fluidically connects the second duct 14b to the second circulation ducts 32 via the second inlet manifold 38a and a fourth connection block 44d fluidically connects the second circulation ducts 32 to the third duct 14c via the second outlet manifold 38b.

As mentioned above, according to the invention, the plates 22 are configured so that at least two of the first circulation ducts 30 are adjacent in the vertical direction V. In the remainder of the description, two first adjacent circulation ducts 30 are referred to as an assembly 46.

Depending on the position thereof in the stack of plates 22 forming the heat exchanger according to the invention, this assembly of first adjacent circulation ducts 30 is delimited vertically by the first end plate 40, the second end plate 42, or by a second circulation duct 32. Where applicable, in the core of the heat exchanger, two second circulation ducts 32 extend on the two sides of the assembly 46 formed by two first adjacent circulation ducts 30, in the vertical direction V. In other words, according to the invention, there is at least one sequence formed by the successive stacking of a second circulation duct 32 and the assembly 46 of two first adjacent circulation ducts 30, and this sequence may be repeated vertically so that a second circulation duct 32 is found between a first assembly 46 of two first adjacent circulation ducts 30 and a second assembly 46 of two first adjacent circulation ducts 30.

According to an example of the invention, all of the first circulation ducts 30 of the heat exchanger 2 are arranged in assemblies 46 as described above, each of the assemblies 46 being separated from another assembly 46 by a single second circulation duct 32 in the vertical direction V.

Consequently, the circulation ducts 28 are distributed so that a number of first circulation ducts 30 is greater than the number of second circulation ducts 32, with the number of first circulation ducts 30 potentially being equal to or greater than twice the number of second circulation ducts 32.

Such an arrangement of the circulation ducts 30, 32 in the heat exchanger 2 is used to increase the flow area for the low-pressure refrigerant fluid in the heat exchanger 2 compared to the flow area of the high-pressure refrigerant fluid, thereby helping to reduce the pressure drop in the low-pressure part of the circuit and to increase the quality of the heat exchange 2 between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid.

Since the plates are stacked on top of one another and participate in delimiting the circulation ducts 28 between each other, within the plurality of plates 22, a central plate 221 participates in delimiting two first adjacent circulation ducts 30 forming an assembly 46 and the two neighboring plates 222, 223 of this central plate 221 each participate in delimiting on the one hand one of the first circulation ducts 30 of the assembly 46 and on the other hand a second circulation duct 32 adjacent to this assembly 46.

As shown in particular in the detail in FIG. 4, these two neighboring plates 222, 223 have different configurations to enable or prevent fluidic communication of the first circulation ducts 30 and of the second circulation ducts 32 with the corresponding manifolds.

An upper face 48 and a lower face 50 of each of the exchange surfaces 24 of each of the plates 22, which are opposite one another in the vertical direction V, are defined, the upper face 48 in this case being the face oriented towards the second end plate 42 and the lower face 50 being in this case the face oriented towards the first end plate 40.

With the exception of the end plates 40, 42, each of the faces 48, 50 of a plate 22 participates in delimiting a separate circulation duct 30, 32. More specifically, for a central plate 221, the upper face 48 and the lower face 50 each participate in delimiting one of the first adjacent circulation ducts 30 forming an assembly 46, as mentioned above. And for a neighboring plate 222, 223 of this central plate, either the upper face 48 or the lower face 50 also participates in delimiting one of the first adjacent circulation ducts 30 of the assembly 46, while the other face 48, 50 participates in delimiting a second circulation duct 32.

Peripheral portions 52 of the exchange surface of each of the plates 22 are also defined, represented using dotted lines in FIG. 3 and each surrounding the openings 34 formed in the exchange surface. In a given manifold formed by the alignment of openings 34 made in the plurality of plates 22, the peripheral portions 52 of two adjacent plates may be made integral with one another to prevent the fluid circulating between these two plates from flowing into the manifold, or conversely arranged at a distance from one another to enable the fluid circulating between these two plates to communicate with the manifold.

For the manifolds 36a, 36b bringing the fluid into and out of the low-pressure circuit, in order to form an assembly as mentioned above of two first adjacent circulation ducts 30, the peripheral portion 52 of one of the neighboring plates 222 of the central plate 221 is deformed, away from the central plate, to come into contact with another plate and to form, notably by brazing, a sealed zone preventing fluidic communication between a second circulation duct 32 and the corresponding manifold. The peripheral portion 52 of the other neighboring plate 223 has a similar configuration to the peripheral portion of the central plate 221, in this case a substantially flat configuration.

In the plurality of plates illustrated in FIG. 4, it is therefore possible to distinguish primary plates 22a, having a peripheral portion 52 in the same plane as the main plane of elongation of the exchange surface 24, and secondary plates 22b in which the peripheral portion 52 is deformed to come into contact with the peripheral portion of a primary plate 22a. It is also notable according to the invention that the internal heat exchanger with plates includes two successive primary plates 22a at regular intervals.

In this context, it is also notable that the thickness of the plate edges 220 participating in delimiting a manifold 36a, 36b associated with the low-pressure circuit varies from one edge to the other, notably as a result of the joining at regular intervals of two adjacent peripheral portions to prevent fluidic communication between a second circulation duct 32 and this manifold. More specifically, a plate edge 220 formed by the peripheral portion 52 of the central plate 221 has a first thickness e1 substantially equal to the average thickness of each of the plates of the exchanger, and the plate edge 53 adjacent to this peripheral portion 52 of the central plate 221 has a second thickness e2 substantially equal to twice the average thickness of each of the plates of the exchanger, since it is formed by joining the peripheral portions of two adjacent plates.

According to the illustrated example of the invention, at least one of the exchange surfaces 24 of one of the plates 22 of the plurality of plates 22 comprises a boss 60. The boss 60, shown by way of example in FIG. 4, forms a projection from the lower face 50 of the corresponding plate, tending to approach the exchange surface of the adjacent plate facing this lower face 50. The flow area of the refrigerant fluid is thus locally reduced, and this results in a disturbance of the circulation of the refrigerant fluid inside the circulation duct delimited by the lower face 50 provided with the boss and the upper face 48 of the adjacent plate. Such a disturbance of the circulation of the refrigerant fluid in the circulation ducts increases the heat exchanges between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid circulating in the respective circulation ducts 30, 32 thereof.

The invention described above achieves the stated objective by proposing an internal heat exchanger with plates in which the plates are more specifically configured and arranged in relation to one another to enable a heat exchange inside a refrigerant-fluid circuit that is not subject to pressure drops in the low-pressure part of this circuit. However, it should be noted that the invention is not limited solely to the means and configurations described and illustrated, and is also applicable to any equivalent means or configurations, and to any combination of such means or configurations.

Claims

1. A heat exchanged with plates of a refrigerant-fluid circuit, the heat exchanged comprising at least one plurality of plates stacked on top of one another in a vertical stacking direction, with adjacent plates between each other delimiting a plurality of first circulation ducts for the refrigerant fluid in a low-pressure part of the circuit and a plurality of second circulation ducts for the refrigerant fluid in a high-pressure part of the circuit, at least some of the plurality of plates of the heat exchanged including a plurality of openings, of which some form a first inlet manifold and others form a first outlet manifold for the low-pressure refrigerant fluid in communication with the first circulation ducts, and of which some form a second inlet manifold and others form a second outlet manifold for the high-pressure refrigerant fluid in communication with the second circulation ducts, the heat exchanged being wherein at least two of the first circulation ducts are adjacent in the vertical stacking direction.

2. The heat exchanged as claimed in claim 1, wherein the number of first circulation ducts, respectively delimited by two adjacent plates of the plurality of plates and in communication with the low-pressure part of the circuit, is greater than the number of second circulation ducts, respectively delimited by two adjacent plates of the plurality of plates and in communication with the high-pressure part of the circuit.

3. The heat exchanged as claimed in claim 1, wherein the circulation ducts delimited by the adjacent plates of the plurality of plates are arranged so that a second circulation duct extends on the two sides, in the vertical direction, of the assembly formed by the at least two first adjacent circulation ducts.

4. The heat exchanged as claimed in claim 1, wherein the first circulation ducts are arranged in assemblies of two first circulation ducts that are adjacent in the vertical direction and partially delimited respectively by one and the same plate.

5. The heat exchanged as claimed in claim 4, wherein each of the assemblies is separated from another assembly by a single second circulation duct in the vertical direction.

6. The heat exchanged as claimed in claim 1, wherein each of the plates has peripheral portions surrounding each of the openings, a peripheral portion of a plate ) potentially being made integral with the peripheral portion of an adjacent plate to isolate the circulation duct delimited between these adjacent plates from the manifold formed by the corresponding openings.

7. The heat exchanged as claimed in claim 1, wherein, at the low-pressure refrigerant-fluid manifolds, the plates are distributed into primary plates, with a flat peripheral portion that extends in a plane substantially perpendicular to the vertical stacking direction, and secondary plates in which the peripheral portion is deformed to come into contact with the peripheral portion of a primary plate, the internal heat exchanger with plates being configured so that the plurality of plates includes two successive primary plates at regular intervals.

8. The heat exchanged as claimed in claim 7, wherein the thicknesses of the edges of the peripheral portions ) participating in delimiting a manifold formed by a plurality of openings differ from one edge to the other in the vertical stacking direction.

9. The heat exchanged as claimed in claim 1, wherein each of the plates includes at least one exchange surface against which the refrigerant fluid circulates and a raised edge, the plurality of plates being stacked so that all of the raised edges of each of the plates are in contact with each other and that the at least one exchange surface is at a non-zero distance so as to form the circulation ducts.

10. A refrigerant-fluid circuit comprising at least one heat exchanger with plates of a refrigerant-fluid circuit, the heat exchanger including at least one plurality of plates stacked on top of one another in a vertical stacking direction, with adjacent plates between each other delimiting a plurality of first circulation ducts for the refrigerant fluid in a low-pressure part of the circuit and a plurality of second circulation ducts for the refrigerant fluid in a high-pressure part of the circuit, at least some of the plurality of plates of the heat exchanger including a plurality of openings, of which some form a first inlet manifold and others form a first outlet manifold for the low-pressure refrigerant fluid in communication with the first circulation ducts, and of which some form a second inlet manifold and others form a second outlet manifold for the high-pressure refrigerant fluid in communication with the second circulation ducts, the heat exchanger being wherein at least two of the first circulation ducts are adjacent in the vertical stacking direction, the refrigerant-fluid circuit further comprising a high-pressure part and a low-pressure part, the heat exchanged being arranged fluidically inside the circuit to enable a heat exchange between the refrigerant fluid circulating primarily in gas form in the low-pressure part with the refrigerant fluid circulating primarily in liquid form in the high-pressure part.