Internal heat exchanger with plates

Abstract

An internal heat exchanger having plates. The invention relates to a heat exchanger (2) with plates (22) of a refrigerant circuit, comprising at least a plurality of plates (22) stacked one on top of the other in a vertical stacking direction (V), adjacent plates (22) between which delimit a plurality of first refrigerant flow ducts (30) of a low-pressure portion (18) of the circuit (1) and a plurality of second refrigerant flow ducts (32) of a high-pressure portion (12) of the circuit (1), at least two of the first flow ducts (30) are adjacent in the vertical direction (V).

Description

Technical Field

[0001] The invention relates to an internal heat exchanger in a refrigerant fluid circuit of a motor vehicle. Background Art

[0002] The refrigerant fluid circuit is used to regulate the temperature of the air flow directed toward the passenger compartment of a motor vehicle and / or to participate in cooling various elements of the vehicle, such as an electrical storage device. To this end, the refrigerant fluid circuit comprises a heat exchanger, a compressor and an expansion device, which respectively increase and reduce the pressure of the refrigerant fluid as it circulates through the circuit, making it possible to distinguish high-pressure and low-pressure portions in the circuit.

[0003] In such a circuit, the refrigerant fluid entering the compressor must be completely in the gaseous state in order not to damage the compressor. For this reason, it is known to use accumulation devices to recover the continuous liquid portion of the refrigerant fluid flowing from one of the heat exchangers arranged upstream of the compressor.

[0004] In order to ensure that the refrigerant fluid directed to the compressor is entirely in the gaseous state, it is also known to incorporate an internal heat exchanger arranged directly upstream of the compressor and intended to increase the evaporation capacity of the refrigerant fluid. More specifically, the internal heat exchanger is dedicated to the refrigerant fluid circuit and is traversed only by refrigerant fluid, in one direction by the refrigerant fluid circulating in the high-pressure portion of the circuit and in the other direction by the refrigerant fluid circulating in the low-pressure portion of the circuit.

[0005] The internal heat exchanger is usually in the form of two concentric tubes, corresponding respectively to the low-pressure part and the high-pressure part of the circuit, each of the two concentric tubes having a common wall, and the heat exchange required to evaporate the refrigerant fluid from the low-pressure part of the circuit before it enters the compressor is carried out through the wall common to the two concentric tubes. However, a disadvantage of this internal heat exchanger in the form of concentric tubes is that, on the one hand, it occupies a large space in the vehicle and, on the other hand, its efficiency, which should be improved, is due to the significant pressure drop in the tubes through which the low-pressure refrigerant fluid passes, thereby limiting the evaporation performance of the refrigerant fluid. Summary of the invention

[0006] The present invention therefore proposes to solve these problems by providing an internal heat exchanger with plates capable of withstanding the high pressure conditions of the refrigerant fluid circuit while limiting the pressure drop of the refrigerant fluid in the low pressure circuit, thereby ensuring an optimal evaporation capacity of the low pressure refrigerant fluid. The specific structure of the plate type internal heat exchanger significantly ensures space saving compared to the prior art structures in the form of concentric tubes. These effects improve the overall operation of the refrigerant fluid circuit.

[0007] The present invention more specifically relates to a heat exchanger having plates for a refrigerant fluid circuit, the heat exchanger comprising at least one group of a plurality of plates stacked one on top of another in a vertical stacking direction, adjacent plates defining between each other a plurality of first flow conduits for the refrigerant fluid in the low-pressure portion of the circuit and a plurality of second flow conduits for the refrigerant fluid in the high-pressure portion of the circuit, at least some of the plurality of plates of the heat exchanger comprising a plurality of openings, some of the openings forming a first inlet manifold and other of the openings forming a first outlet manifold for the low-pressure refrigerant fluid and communicating with the first flow conduits, and some of the openings forming a second inlet manifold and other of the openings forming a second outlet manifold for the high-pressure refrigerant fluid and communicating with the second flow conduits, the heat exchanger being characterized in that at least two of the first flow conduits are adjacent in the vertical stacking direction.

[0008] The heat exchanger is a plate exchanger formed by stacking plates, the plates being configured to define refrigerant fluid circulation channels between each other, the plates being connected to each other to provide or prevent fluid communication between the circulation channels they participate in defining and a manifold extending through the plates in the stacking direction. An appropriate gap between two adjacent plates establishes a refrigerant fluid circulation channel, and the fact that this channel leads to a manifold associated with a low-pressure portion of the circuit or to a manifold associated with a high-pressure portion of the circuit enables this channel to serve as a first low-pressure circulation channel or a second high-pressure circulation channel.

[0009] In this case, the heat exchanger is an internal heat exchanger arranged in the refrigerant fluid circuit upstream of the 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 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 evaporation capacity of the low-pressure refrigerant fluid before it enters the compressor. The internal heat exchanger then exchanges heat between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid, by recovering some heat from the high-pressure refrigerant fluid, thereby transforming the continuous liquid portion of the low-pressure refrigerant fluid into the gaseous state.

[0010] The particular arrangement of the circulation ducts inside the internal heat exchanger with plates according to the invention is advantageous because it makes the number of first circulation ducts associated with the circulation of the low-pressure refrigerant fluid 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 circulates through the heat exchanger, thereby improving the heat exchange with the high-pressure refrigerant fluid in a plate exchanger that is smaller than a concentric tube exchanger. This improves the evaporation capacity of the low-pressure refrigerant fluid in the internal heat exchanger.

[0011] According to one feature of the invention, the flow ducts defined by adjacent plates of the plurality of plates are arranged so that a second flow duct extends in a vertical direction on both sides of the assembly formed by the at least two adjacent first flow ducts.

[0012] According to one feature of the invention, the first flow ducts are arranged in an assembly of two first flow ducts, the two first flow ducts are adjacent in the vertical direction and are respectively partially bounded by the same plate. In other words, at least one plate of the plurality of plates defines two adjacent first flow ducts. In this case, three adjacent plates are required to define two adjacent first flow ducts, and the plate arranged in the center of the stack of these three adjacent plates, or the central plate, is common to the two adjacent first flow ducts.

[0013] According to one feature of the present invention, each assembly is separated from another assembly by a single second circulation pipe in the vertical direction. Therefore, all first circulation pipes can be arranged in an assembly of two first circulation pipes adjacent in the vertical direction, separated by a single second circulation pipe, so that the circulation pipes tend to be distributed so that the number of the plurality of first circulation pipes associated with the circulation of the low-pressure refrigerant fluid is equal to or greater than the number of the second circulation pipes associated with the circulation of the high-pressure refrigerant fluid.

[0014] According to one feature of the invention, each plate has a peripheral portion surrounding each opening, the peripheral portion of the plate being integral with the peripheral portion of an adjacent plate to isolate the flow duct defined between these adjacent plates from the manifold formed by the corresponding openings.

[0015] According to one feature of the present invention, at the low-pressure refrigerant fluid manifold, the plates are distributed into a main plate with a flat peripheral portion extending in a plane substantially perpendicular to the vertical stacking direction and sub-plates, in which the peripheral portion is deformed to contact with the peripheral portion of the main plate, and the internal heat exchanger having the plates is configured so that the plurality of plates includes two consecutive main plates at a fixed interval.

[0016] According to one feature of the invention, the thickness of the edge participating in delimiting the peripheral portion of the manifold formed by the plurality of openings varies from one edge to another in the vertical stacking direction.

[0017] According to one feature of the invention, each plate comprises at least one exchange surface and a raised edge, against which the refrigerant fluid circulates, and the plurality of plates are stacked so that all the raised edges of each plate are in contact with each other and the distance of each exchange surface is not zero, thereby forming a flow duct.

[0018] According to one feature of the invention, at least one of the exchange surfaces of one of the plates of said plurality of plates comprises a projection.

[0019] An irregular profile is a profile that extends beyond the main extension plane of the plate. For example, the irregular profile can be formed by a deformation of the exchange surface of the plate, thereby disturbing the circulation of the refrigerant fluid against the upper and lower faces of the plate. This disturbance of the circulation of the refrigerant fluid increases the heat exchange between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid circulating in their respective circulation ducts.

[0020] The present invention also relates to a refrigerant fluid circuit, comprising at least one heat exchanger according to any one of the aforementioned features, the refrigerant fluid circuit comprising a high-pressure part and a low-pressure part, the heat exchanger being fluidly arranged in the circuit so that heat exchange can be carried out between the refrigerant fluid circulating in the low-pressure part in gaseous form and the refrigerant fluid circulating in the high-pressure part in liquid form.

[0021] According to one feature of the invention, the first flow conduit of the heat exchanger is connected to the low-pressure part of the circuit through the first and second connecting blocks, and the second flow conduit of the heat exchanger is connected to the high-pressure part of the circuit through the third and fourth connecting blocks of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further features, details and advantages of the present invention will become more apparent from the following description which is given by way of example only and which is made with reference to the accompanying drawings, in which:

[0023] Figure 1 is a schematic diagram of a portion of a refrigerant fluid circuit;

[0024] Figure 2 is a cross-sectional view of a heat exchanger in a refrigerant fluid circuit;

[0025] Figure 3 is formed Figure 2 A perspective view of the stacked plates of the heat exchanger;

[0026] Figure 4 yes Figure 2 Detailed schematic diagram. DETAILED DESCRIPTION

[0027] First, it should be noted that although the drawings disclose the embodiments of the present invention in detail, these drawings can obviously be used to better define the present invention where appropriate. It should also be noted that these drawings only disclose embodiments of the present invention. Finally, in all drawings, the same reference numerals represent the same elements.

[0028] Figure 1A refrigerant fluid circuit 1 is shown, comprising at least one heat exchanger 2 according to the invention, in this case an internal heat exchanger 2. The refrigerant fluid circuit 1 further 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 which is separated from the circuit 1 and is led, for example, to the passenger compartment of a vehicle, or to an electrical storage device of an electric or hybrid vehicle.

[0029] It should be noted that the refrigerant fluid circuit described in detail in the following description is merely an exemplary embodiment and that the circuit may include further elements not described here.

[0030] Figure 1 The compressor 4 schematically shown in Figure 1 compresses the refrigerant fluid to increase its pressure and thus its temperature. Therefore, at the outlet of the compressor 4, the high-pressure refrigerant fluid is in a gaseous state and has a high temperature, i.e. a temperature higher than that at the inlet of the compressor 4. Therefore, at the outlet of the compressor 4, the refrigerant fluid circulates in the high-pressure part 12 of the refrigerant fluid circuit 1.

[0031] The first pipe 14a extends between the compressor 4 and the condenser 6, which enables heat exchange between the heat transfer fluid 15 passing through the condenser and the high temperature and high pressure refrigerant fluid, which transfers the heat to the heat transfer fluid 15. At the outlet of the condenser 6, the refrigerant fluid maintains a high pressure, but the temperature is lower than the temperature at the inlet of the condenser, so that the refrigerant fluid is output in two phases or in a completely liquid state.

[0032] At the outlet of the condenser 6, the refrigerant fluid is led to a second pipe 14b extending between the condenser 6 and the above-mentioned internal heat exchanger 2. The internal heat exchanger 2 is configured to be passed through by the refrigerant fluid in two opposite directions, the refrigerant fluid being at a high pressure in the first direction and at a 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 the low-pressure part 18 of the refrigerant fluid circuit 1. This heat exchange improves the thermodynamic cycle performance achieved by the refrigerant fluid circuit 1. The structure of the internal heat exchanger 2 is described in detail in the following description.

[0033] After passing the internal heat exchanger 2, the refrigerant fluid circulates in a third pipe 14c connecting said internal heat exchanger 2 to the evaporator 8. More specifically, the third pipe 14c comprises at least one expansion device 20 which reduces the pressure and the evaporation point of the high-pressure refrigerant fluid before it enters the evaporator 8. The high-pressure portion 12 of the refrigerant fluid circuit 1 thus gives way to the aforementioned low-pressure portion 18 after the expansion device 20.

[0034] 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 passing through said evaporator 8, for example with the aim of cooling an electrical storage device (not shown). More specifically, this heat transfer fluid passing through the evaporator 8 transfers its heat to the heat transfer fluid circulating in the evaporator 8, so that the heat transfer fluid evaporates. Thus, the refrigerant fluid evaporates in the evaporator 8 under the effect of the heat taken from the heat transfer fluid 21, the expansion device 20 lowering the evaporation point of the refrigerant fluid. Therefore, at the outlet of the evaporator 8, the refrigerant fluid is mainly in a gaseous state.

[0035] At the outlet of the evaporator 8, the refrigerant fluid is introduced into a fourth duct 14d leading to an accumulation device 10, in this case for example an accumulation bottle. The accumulation device 10 is intended to collect the continuous liquid portion of the refrigerant fluid flowing out of the evaporator 8. The refrigerant fluid must in this way pass through the accumulation device 10 before entering the compressor 4, which can only receive refrigerant fluid in the gaseous state.

[0036] At the outlet of the accumulation device 10, the refrigerant fluid enters the fifth pipe 14e, which leads the fluid to 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 way ensures that the refrigerant fluid coming out of the internal heat exchanger 2 is only in the gaseous state before it enters the compressor 4.

[0037] In this case, the heat exchanger according to the present invention is configured to ensure optimal efficiency of heat exchange, in particular, evaporation efficiency of the refrigerant fluid when the refrigerant fluid circulates through the low-pressure portion, so as not to damage the compressor 4 arranged downstream of the low-pressure portion, which damage could reduce the operating efficiency of the refrigerant fluid circuit 1.

[0038] Therefore, the internal heat exchanger 2 according to the invention is described in more detail below, with particular reference to Figures 2 to 4 .

[0039] The internal heat exchanger 2 is a plate exchanger comprising plates 22 stacked on one another, the plates 22 being configured so that the refrigerant fluid can circulate in the ducts formed between two adjacent plates, the plates being configured so as to form low-pressure ducts 30 (i.e. ducts connected only to the low-pressure portion 18 of the circuit) and high-pressure ducts 32 (i.e. ducts connected only to the high-pressure portion 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, in particular so that the number of low-pressure ducts is equal to or greater than twice the number of high-pressure ducts.

[0040] More specifically, the internal heat exchanger 2 according to the present invention comprises a plurality of plates 22 stacked one on top of another in a vertical stacking direction V. Each plate 22 is tub-shaped with an exchange surface 24 surrounded at the periphery by a raised edge 26. The plates 22 are stacked so that the raised edge 26 of each plate 22 is in contact with at least one other raised edge 26 and so that the exchange surface 24 of each plate 22 is at a non-zero distance from the exchange surface 24 of an adjacent plate in the vertical stacking direction V. Refrigerant fluid circulation conduits 28 are thus formed between two adjacent plates, each conduit being configured to be in fluid communication with a fluid inlet and a fluid outlet connected to a high-pressure part or a low-pressure part of the circuit. More specifically, adjacent plates 22 to one another define a plurality of first circulation conduits 30 for the refrigerant fluid in the low-pressure part 18 of the circuit and a plurality of second circulation conduits 32 for the refrigerant fluid in the high-pressure part 12 of the circuit.

[0041] At least some of the plurality of plates 22 of the heat exchanger 2 have a plurality of openings 34, wherein some of the openings 34 are arranged vertically stacked on top of each other to form a plurality of manifolds, in particular Figure 3 Thus, the arrangement of the openings 34 defines, on the one hand, a first inlet manifold 36a and a first outlet manifold 36b for low-pressure refrigerant fluid, which are intended to be in fluid communication with each first circulation duct 30, and, on the other hand, a second inlet manifold 38a and a second outlet manifold 38b for high-pressure refrigerant fluid, which are intended to be in fluid communication with each second circulation duct 32. Each manifold 36a, 36b, 38a, 38b is formed by an alignment of openings and extends vertically through the plurality of plates 22.

[0042] Especially Figure 3 As shown, one manifold 36a, 36b, 38a, 38b is advantageously formed at each corner of the plate heat exchanger, it being understood that the two inlet manifolds 36a, 38a may be diagonally opposite, but this does not mean that a different arrangement is outside the scope of the invention, provided that, as described above, the number of first flow ducts inside the exchanger is greater than the number of second flow ducts. Without limiting the invention, the diagonally opposite arrangement of the inlet manifolds creates a cross-circulation of the refrigerant fluid in the first low-pressure flow duct 30 and a cross-circulation of the refrigerant fluid in the second high-pressure flow duct 32 inside the internal heat exchanger 2, thereby contributing to improving the quality of the heat exchange. This alternating direction of flow is Figure 4 It can be seen particularly in FIG. 1 , where the flow direction of the refrigerant fluid is shown using arrows, more specifically, a first arrow S1 is used for a first flow direction in the first flow conduit 30 , and a second arrow S2 is used for a second flow direction in the second flow conduit 32 .

[0043] Furthermore, a first end plate 40 and a second end plate 42 are defined, each of which is arranged at a vertical end of the stack of plates 22. The first end plate 40 then has no openings 34, thus contributing to vertically closing the volume of the heat exchanger 2. Furthermore, in the illustrated example of the invention, the second end plate 42 carries four connection blocks 44a, 44b, 44c, 44d, which are arranged at Figure 1 , and are intended to be arranged facing each manifold 36a, 36b, 38a, 38b formed by an opening 34 in the plate 22. In other words, each connection block 44a, 44b, 44c, 44d is arranged on the second end plate 42, covering the opening 34 formed in the second end plate 42.

[0044] Thus, the connection blocks 44a, 44b, 44c, 44d provide fluid connections between the pipes 14b, 14c, 14e, 14f of the above-mentioned refrigerant fluid circuit 1 and the flow pipes 30, 32 defined by the plate 22. More specifically, the first connection block 44a fluidly connects the fifth pipe 14e to the first flow pipe 30 via the first inlet manifold 36a, the second connection block 44b connects the first flow pipe 30 to the sixth pipe 14f via the first outlet manifold 36b, the third connection block 44c fluidly connects the second pipe 14b to the second flow pipe 32 via the second inlet manifold 38a, and the fourth connection block 44d fluidly connects the second flow pipe 32 to the third pipe 14c via the second outlet manifold 38b.

[0045] As described above, according to the present invention, the plate 22 is configured such that at least two of the first flow ducts 30 are adjacent in the vertical direction V. In the remainder of the description, two adjacent first flow ducts 30 are referred to as an assembly 46 .

[0046] Depending on its position in the stack of plates 22 forming the heat exchanger according to the invention, this assembly of adjacent first flow ducts 30 is delimited vertically by the first end plate 40, the second end plate 42 or the second flow ducts 32. Where applicable, in the core of the heat exchanger, two second flow ducts 32 extend in the vertical direction V on both sides of an assembly 46 formed by two adjacent first flow ducts 30. In other words, according to the invention, there is at least one sequence formed by a continuous stack of second flow ducts 32 and an assembly 46 of two adjacent first flow ducts 30, and this sequence can be repeated vertically so that a second flow duct 32 is produced between a first assembly 46 of two adjacent first flow ducts 30 and a second assembly 46 of two adjacent first flow ducts 30.

[0047] According to one example of the present invention, all first flow conduits 30 of the heat exchanger 2 are arranged in the assembly 46 as described above, and each assembly 46 is separated from another assembly 46 in the vertical direction V by a single second flow conduit 32 .

[0048] Therefore, the flow conduits 28 are distributed such that the number of the first flow conduits 30 is greater than the number of the second flow conduits 32 , and the number of the first flow conduits 30 may be equal to or greater than twice the number of the second flow conduits 32 .

[0049] This arrangement of the flow pipes 30, 32 in the heat exchanger 2 is used to increase the flow area of ​​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 increase the quality of the heat exchange 2 between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid.

[0050] Since these plates are stacked on each other and participate in defining the flow ducts 28 located between each other, within the multiple plates 22, the central plate 221 participates in defining two adjacent first flow ducts 30 that form the component 46, and the two adjacent plates 222 and 223 of the central plate 221 participate in defining one of the first flow ducts 30 of the component 46 on the one hand, and participate in defining the second flow duct 32 adjacent to the component 46 on the other hand.

[0051] like Figure 4 As particularly shown in detail in FIG. 2 , the two adjacent plates 222 , 223 have different configurations to enable or prevent fluid communication between the first flow conduit 30 and the second flow conduit 32 and the corresponding manifold.

[0052] Each exchange surface 24 of each plate 22 is defined by an upper face 48 and a lower face 50 opposite one another in the vertical direction V, the upper face 48 being in this case 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 .

[0053] With the exception of the end plates 40, 42, each face 48, 50 of the plates 22 participates in defining a separate flow duct 30, 32. More specifically, for the central plate 221, the upper face 48 and the lower face 50 each participate in defining one of the adjacent first flow ducts 30 forming the assembly 46, as described above. And for the adjacent plates 222, 223 of the central plate, either the upper face 48 or the lower face 50 also participates in defining one of the adjacent first flow ducts 30 of the assembly 46, while the other face 48, 50 participates in defining the second flow duct 32.

[0054] A peripheral portion 52 of the exchange surface of each plate 22 is also defined, Figure 3, and each peripheral portion surrounds an opening 34 formed in the exchange surface. In a given manifold formed by the alignment of the openings 34 formed 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 the two plates from flowing into the manifold, or conversely be arranged at a distance from one another to enable the fluid circulating between the two plates to communicate with the manifold.

[0055] For the manifolds 36a, 36b that bring fluid into and out of the low-pressure circuit, in order to form an assembly of two adjacent first flow ducts 30 as described above, the peripheral portion 52 of one of the adjacent plates 222 of the central plate 221 is deformed away from the central plate to contact the other plate and form a sealing area (particularly by brazing) to prevent fluid communication between the second flow duct 32 and the corresponding manifold. The peripheral portion 52 of the other adjacent plate 223 has a similar configuration to the peripheral portion of the central plate 221, in this case a substantially flat configuration.

[0056] Therefore, in Figure 4 Among the plurality of plates shown, it is possible to distinguish a main plate 22a having a peripheral portion 52 in the same plane as the main plane of extension of the exchange surface 24, and a secondary plate 22b, in which the peripheral portion 52 is deformed so as to come into contact with the peripheral portion of the main plate 22a. It is also worth noting that according to the invention, the internal heat exchanger with plates comprises two main plates 22a consecutively spaced at regular intervals.

[0057] In this case, it is also worth noting that the thickness of the plate edge 220 participating in defining the manifolds 36a, 36b associated with the low-pressure circuit varies from one edge to the other, in particular due to the joining of two adjacent peripheral portions at fixed intervals to prevent fluid communication between the second flow duct 32 and this manifold. More specifically, the 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 plate 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 plate of the exchanger, since it is formed by joining the peripheral portions of two adjacent plates.

[0058] 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 protrusion 60 . Figure 4The protrusions 60 shown by way of example in the figure are formed as protrusions from the lower face 50 of the corresponding plate, tending to approach the exchange surface of the adjacent plate facing the lower face 50. As a result, the flow area of ​​the refrigerant fluid is locally reduced, which disturbs the circulation of the refrigerant fluid inside the flow channel defined by the lower face 50 provided with the protrusions and the upper face 48 of the adjacent plate. Such disturbance of the circulation of the refrigerant fluid in the flow channel increases the heat exchange between the low-pressure refrigerant fluid and the high-pressure refrigerant fluid circulating in its corresponding flow channel 30, 32.

[0059] The invention described above achieves the stated purpose by proposing an internal heat exchanger with plates which are more particularly configured and arranged relative to each other so that the heat exchange inside the refrigerant fluid circuit is not affected by the pressure drop in the low-pressure part of this circuit. However, it should be noted that the invention is not limited only to the devices and configurations described and shown, but also applies to any equivalent means or configurations, as well as any combination of these means or configurations.

Claims

1. A heat exchanger (2) having plates (22) of a refrigerant fluid circuit (1), the heat exchanger (2) comprising at least one set of a plurality of plates (22) stacked one on top of another in a vertical stacking direction (V), adjacent plates (22) defining between one another a plurality of first flow ducts (30) for the refrigerant fluid in a low-pressure portion (18) of the circuit (1) and a plurality of second flow ducts (32) for the refrigerant fluid in a high-pressure portion (12) of the circuit (1), at least some of the plurality of plates (22) of the heat exchanger (2) comprising a plurality of openings (34) , some of the openings (34) form a first inlet manifold (36a), and other openings (34) form a first outlet manifold (36b) for the low-pressure refrigerant fluid and connected to the first circulation pipe (30), and some of the openings (34) form a second inlet manifold (38a), and other openings (34) form a second outlet manifold (38b) for the high-pressure refrigerant fluid and connected to the second circulation pipe (32), and the heat exchanger (2) is characterized in that at least two of the first circulation pipes (30) are adjacent in the vertical stacking direction (V).

2. The heat exchanger (2) according to claim 1, wherein: The number of first flow conduits (30) respectively defined by two adjacent plates among the plurality of plates (22) and communicating with the low-pressure portion (18) of the circuit is greater than the number of second flow conduits (32) respectively defined by two adjacent plates among the plurality of plates (22) and communicating with the high-pressure portion (12) of the circuit (1).

3. A heat exchanger (2) according to any one of the preceding claims, wherein: The flow ducts defined by adjacent plates of the plurality of plates (22) are arranged such that a second flow duct (32) extends in a vertical direction (V) on both sides of the assembly formed by the at least two adjacent first flow ducts (30).

4. A heat exchanger (2) according to any one of the preceding claims, wherein: The first flow duct (30) is arranged in an assembly (46) of two first flow ducts (30) which are adjacent in a vertical direction (V) and are each partially delimited by the same plate (22).

5. The heat exchanger (2) according to claim 4, wherein: Each of the modules (46) is separated from another module in the vertical direction (V) by a single second flow conduit (32).

6. A heat exchanger (2) according to any one of the preceding claims, wherein: Each of the plates (22) has a peripheral portion (52) surrounding each of the openings (34), and the peripheral portion (52) of a plate (22) can be made integral with the peripheral portion (52) of an adjacent plate to isolate the flow duct defined between these adjacent plates from the manifold formed by the corresponding openings.

7. A heat exchanger (2) according to any one of the preceding claims, wherein: At the low-pressure refrigerant fluid manifold, the plates (22) are distributed into a main plate (22a) and a sub-plate (22b), the main plate (22a) having a flat peripheral portion (52) extending in a plane substantially perpendicular to the vertical stacking direction, in the sub-plate, the peripheral portion (52) is deformed to contact the peripheral portion (52) of the main plate (22a), and the internal heat exchanger having plates is configured so that the plurality of plates include two consecutive main plates (22a) at a fixed interval.

8. The heat exchanger (2) according to claim 7, wherein: The thickness of the edge of the peripheral portion (52) participating in defining the manifold formed by the plurality of openings (34) varies from one edge to another in the vertical stacking direction (V).

9. A heat exchanger (2) as claimed in any one of the preceding claims, wherein: Each of the plates (22) comprises at least one exchange surface (24) and a raised edge (26), against which the refrigerant fluid flows, and the plurality of plates (22) are stacked so that all the raised edges (26) of each of the plates (22) are in contact with each other and the distance of each of the exchange surfaces (24) is not zero, thereby forming the flow duct (30, 32).

10. A refrigerant fluid circuit (1) comprising at least one heat exchanger (2) as claimed in any one of the preceding claims, the refrigerant fluid circuit (1) comprising a high-pressure part (12) and a low-pressure part (18), the heat exchanger (2) being fluidically arranged inside the circuit (1) so as to enable heat exchange between the refrigerant fluid circulating mainly in gaseous form in the low-pressure part (18) and the refrigerant fluid circulating mainly in liquid form in the high-pressure part (12).

Images