Main plate for heat exchanger, heat exchanger element, heat exchanger, powertrain and associated process.

Abstract

This main plate for the heat exchanger (40) is provided with a first heat exchange stage (44) having heat exchange walls (46) between a primary fluid and a first fluid, a second heat exchange stage (48) having heat exchange walls (50) between the primary fluid and a second fluid, and a junction (52) separating the first and second heat exchange stages (44, 48), at least one orifice being formed in the junction (52). Figure for the abbreviation: Fig 4

Description

Title of the invention: Main plate for heat exchanger, heat exchanger element, heat exchanger, powertrain and associated process. Technical field

[0001] The present invention relates to the technical field of plate heat exchangers.

[0002] In particular, the present invention relates to a main plate for a heat exchanger, a heat exchanger element comprising such a main plate, a heat exchanger comprising such a heat exchanger element, an associated powertrain comprising such a heat exchanger, and a method for reducing heat exchange between the first and second heat exchange stages of a main plate for a heat exchanger. Previous techniques

[0003] A motor vehicle powertrain may include a turbocharger and a turbocharged internal combustion engine equipped with a cooling circuit.

[0004] It is advantageous to cool the air exiting the turbocharger, for example to a temperature of around 180°C, before injecting it into a cylinder head of the engine, for example at a temperature of around 45°C.

[0005] The cooling circuit of the internal combustion engine may be insufficient to cool the air exiting the turbocharger, particularly in compact powertrain architectures. Description of the invention

[0006] The present invention therefore aims to overcome all or part of the aforementioned drawbacks, and in particular to provide a compact and efficient heat exchanger.

[0007] The invention relates to a main plate for a heat exchanger having a first heat exchange stage with heat exchange walls between a main fluid and a first fluid, a second heat exchange stage with heat exchange walls between the main fluid and a second fluid, and a junction separating the first and second heat exchange stages.

[0008] At least one orifice is formed in Injonction.

[0009] Preferably, the main fluid is intended to be cooled by the first and second fluids, in particular intended to be cooled by the first fluid and then by the second fluid.

[0010] The main plate, equipped with the first and second heat exchange stages, allows for a first heat exchange between the main fluid and the first The fluid in the first heat exchange stage is used to perform a second heat exchange between the main fluid and the second fluid in the second heat exchange stage. Thus, the main plate is suitable for compact, sequential heat exchangers.

[0011] The junction of the main plate conducts heat.

[0012] Said orifice formed in the junction of the main plate makes it possible to reduce the heat exchanges between the first and second heat exchange stages through the junction, in particular to reduce the heat exchanges by conduction between the first and second fluids taking place by heat exchange from the first fluid in the first heat exchange stage to the junction and from the junction to the second fluid in the second heat exchange stage.

[0013] Preferably, the first and second heat exchange stages of the main plate are formed by stamping the main plate.

[0014] Preferably, the first fluid is separate from the second fluid.

[0015] Preferably, the second fluid is at a temperature strictly lower than the temperature of the first fluid.

[0016] According to a first conception, said orifice formed in the junction of the main plate is through.

[0017] Alternatively, the orifice formed in the junction of the main plate is blind.

[0018] Advantageously, a plurality of distinct orifices are formed in the main plate injunction.

[0019] The main fluid may comprise a gas, in particular air. The main fluid may consist of a gas, in particular air.

[0020] The first fluid may be of the type of engine coolant. The first fluid may consist of engine coolant.

[0021] The second fluid may be a heat exchanger coolant. The second fluid may consist of a heat exchanger coolant.

[0022] Advantageously, the first heat exchange stage is provided with an inlet and an outlet for the first fluid, the second heat exchange stage being provided with an inlet and an outlet for the second fluid.

[0023] Optionally, the walls of the first heat exchange stage comprise a first metallic material. The walls of the first heat exchange stage may be formed entirely of the first metallic material.

[0024] Optionally, the walls of the second heat exchange stage comprise a second metallic material. The walls of the second heat exchange stage may be formed entirely of the second metallic material.

[0025] Optionally, the joint includes a third metallic material. The joint may be entirely formed from the third metallic material.

[0026] Advantageously, the first, second and third metallic materials are identical.

[0027] The first heat exchange stage, the second heat exchange stage, and the main plate junction can be monolithic. In particular, the first heat exchange stage can be made of the same material as the junction, and the junction can be made of the same material as the second heat exchange stage.

[0028] The first heat exchange stage can be provided with a first main footprint configured to form at least in part a first circuit for the first fluid when the main plate is assembled with a complementary heat exchanger plate provided with a first complementary footprint.

[0029] The second heat exchange stage can be provided with a second main cavity configured to form at least in part a second circuit for the second fluid when the main plate is assembled with the complementary plate provided with a second complementary cavity.

[0030] The present invention also relates to a heat exchanger element comprising a main heat exchanger plate as defined above and a supplementary heat exchanger plate having a first heat exchange stage with heat exchange walls between the main fluid and the first fluid, a second heat exchange stage with heat exchange walls between the main fluid and the second fluid, and a junction separating the first and second heat exchange stages of the supplementary plate, the main and supplementary plates being stacked and assembled so that the first fluid is able to circulate between the first heat exchange stages of the main and supplementary plates, and so that the second fluid is able to circulate between the second heat exchange stages of the main and supplementary plates.

[0031] Preferably, the heat exchange walls between the main fluid and the first fluid of the first heat exchange stage of the main and complementary plates and the heat exchange walls between the main fluid and the second fluid of the second heat exchange stage of the main and complementary plates are jointly able to compartmentalize the first and second fluids so that the first and second fluids do not mix.

[0032] The junction of the complementary plate can be identical to the junction of the main plate for heat exchanger.

[0033] Advantageously, the first main impression of the first heat exchange stage of the main plate and the first complementary impression of the first heat exchange stage of the complementary plate are assembled together by brazing.

[0034] Advantageously, the second main cavity of the second heat exchange stage of the main plate and the second complementary cavity of the second heat exchange stage of the complementary plate are assembled together by brazing.

[0035] Advantageously, brazing is carried out by depositing a bead of material in the first and second main and complementary cavities.

[0036] The present invention also relates to a heat exchanger comprising a plurality of heat exchanger elements as defined above stacked so that the main fluid is able to circulate between two successive heat exchanger elements of the stack.

[0037] The present invention also relates to a motor vehicle powertrain comprising at least one heat exchanger as defined above, a main supply circuit for said heat exchanger with the main fluid, a first supply circuit for said heat exchanger with the first fluid, and a second supply circuit for said heat exchanger with the second fluid.

[0038] Advantageously, the powertrain includes a heat engine equipped with a cylinder head and a turbocharger configured to compress the main fluid and supply compressed main fluid to the cylinder head, said heat exchanger being configured to cool the compressed main fluid, the main supply circuit being configured to supply said heat exchanger with compressed main fluid to be cooled, and to supply the cylinder head with cooled compressed main fluid.

[0039] The present invention also relates to a method for reducing heat exchange between the first and second heat exchange stages of a main plate for a heat exchanger having a first heat exchange stage with heat exchange walls between a main fluid and a first fluid, a second heat exchange stage with heat exchange walls between the main fluid and a second fluid, and a junction separating the first and second heat exchange stages, the method comprising making at least one orifice in the junction of the main plate. Brief description of the drawings

[0040] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0041] [Fig-1] schematically illustrates a powertrain according to an example of realization of the invention;

[0042] [Fig.2] schematically illustrates a heat exchanger according to an example of an embodiment of the invention;

[0043] [Fig.3] schematically illustrates a stack of heat exchanger elements according to an example of an embodiment of the invention;

[0044] [Fig.4] schematically illustrates a main plate for a heat exchanger according to an example of an embodiment of the invention; and

[0045] [Fig.5] illustrates a method according to an example of an embodiment of the invention. Detailed description

[0046] Fig. 1 schematically represents a powertrain 2 for a motor vehicle comprising a cylinder head 4 attached to a cylinder block, an air intake circuit 6 supplying air to the cylinder head 4, and an exhaust circuit for combustion gases 8.

[0047] The air intake circuit 6 includes an air inlet advantageously equipped with an air filter (not shown) suitable for filtering the air from the air inlet, a compressor 10 suitable for increasing the mass flow rate of the air from the air inlet and a plate heat exchanger 12 suitable for reducing the temperature of the air from the compressor 10, the cooled air being injected into the cylinder head 4. The air intake circuit 6 constitutes here a main supply circuit for the heat exchanger 12.

[0048] The heat exchanger 12 is, for example, a supercharged air cooler or “charged air cooler” in Anglo-Saxon terms.

[0049] The exhaust gas circuit 8 includes a turbine 14 suitable for expanding the exhaust gases from the cylinder head 4, and a catalyst 16 suitable for reducing polluting emissions from the exhaust gases from the turbine 14.

[0050] The powertrain 2 includes a shaft 18 on which the compressor 10 and the turbine 14 are mounted so as to form a turbocharger.

[0051] Fig. 2 schematically represents the heat exchanger 12. The heat exchanger 12 comprises a main fluid circuit 20, in which a main fluid to be cooled circulates, consisting here of air compressed by the compressor 10, and first and second cooling fluid circuits, respectively 22 and 24, in which first and second cooling fluids circulate.

[0052] The heat exchanger 12 includes an inlet 26 and an outlet 28 for the main fluid, which communicate with the main fluid circuit 20.

[0053] Similarly, the heat exchanger 12 includes an inlet 30 and an outlet 32 ​​for the first cooling fluid, which communicate with the first cooling fluid circuit 22. It further includes an inlet 34 and an outlet 36 for the second cooling fluid, which communicate with the second cooling fluid circuit 24.

[0054] The inlets 30 and 34, on the one hand, and the outlets 32 and 36, on the other hand, for the first and second cooling fluids are respectively connected to the first and second powertrain supply circuit 2 for the first and second cooling fluid (not shown).

[0055] According to the embodiment of the heat exchanger 12, as shown by way of example in [Fig. 2], the outlet 32 ​​for the first cooling fluid is arranged between the inlet 26 for the main fluid and the inlet 30 for the first cooling fluid, and the outlet 36 for the second cooling fluid is arranged between the inlet 30 for the first cooling fluid and the inlet 34 for the second cooling fluid. Furthermore, the inlet 34 for the second cooling fluid is arranged between the outlet 36 for the second cooling fluid and the outlet 28 for the main fluid.

[0056] The main fluid flows from the inlet 26 for the main fluid to the outlet 28 for the main fluid, in a heat exchange relationship with the first and second cooling fluids in the first and second cooling fluid circuits 22 and 24, so that a first heat transfer takes place between the main fluid and the first cooling fluid which flows from the inlet 30 for the first cooling fluid to the outlet 32 ​​for the first cooling fluid, then a second heat transfer takes place between the main fluid and the second cooling fluid which flows from the inlet 34 for the second cooling fluid to the outlet 36 for the second cooling fluid.

[0057] The first cooling fluid comprises, for example, a coolant for an engine of the powertrain 2, and here consists of the engine coolant. The second cooling fluid comprises, for example, a coolant for the heat exchanger 12, and here consists of the coolant for the heat exchanger 12.

[0058] The main fluid entering the heat exchanger 12 is at a strictly higher temperature than the first cooling fluid, which is at a strictly higher temperature than the second cooling fluid. For example, the air compressed by the compressor 10 is at a temperature close to at 180°C, the engine coolant is at a temperature of around 110°C, and the coolant of the heat exchanger 12 is at a temperature of around 30°C.

[0059] As more visibly illustrated in [Fig.3], the plate heat exchanger 12 comprises a stack of a plurality of main and complementary plates 40, 42. Each pair of main and complementary plates 40, 42 forming a heat exchanger element 38.

[0060] The heat exchanger elements 38 are stacked so that the main fluid flows between each pair of successive heat exchanger elements 38 of the stack, in particular in a direction transverse to the stacking direction.

[0061] With reference to [Fig.4], each main plate 40 is provided with a first heat exchange stage 44 having heat exchange walls 46 between the main fluid and the first cooling fluid, a second heat exchange stage 48 having heat exchange walls 50 between the main fluid and the second cooling fluid, and a junction 52 separating the first and second heat exchange stages 44, 48.

[0062] The first and second heat exchange stages 44, 48 are, for example, formed by stamping the main plate 40.

[0063] The junction 52 here forms a band of material separating the first and second heat exchange stages 44, 48.

[0064] The walls 46 of the first heat exchange stage 44 of the main plate 40 comprise a first metallic material, for example copper, aluminum, stainless steel or steel.

[0065] The walls 50 of the second heat exchange stage 48 of the main plate 40 comprise a second metallic material, for example copper, aluminum, stainless steel or steel.

[0066] The junction 52 of the main plate 40 includes a third metallic material, for example copper, aluminum, stainless steel or steel.

[0067] Advantageously, the first, second and third metallic materials are identical.

[0068] The first heat exchange stage 44 of the main plate 40 is provided with a first main cavity 54, in particular delimited by the heat exchange walls 46 between the main fluid and the first cooling fluid of the main plate 40. The second heat exchange stage 48 of the main plate 40 is provided with a second main cavity 56, in particular delimited by the heat exchange walls 50 between the main fluid and the second cooling fluid of the main plate 40.

[0069] Similarly, each additional plate 42 is provided with a first heat exchange stage having heat exchange walls between the main fluid and the first cooling fluid, a second heat exchange stage having heat exchange walls between the main fluid and the second cooling fluid, and a junction separating the first and second heat exchange stages of the additional plate 42.

[0070] The walls of the first heat exchange stage of the complementary plate 42 comprise the first metallic material. The walls of the second heat exchange stage of the complementary plate 42 comprise the second metallic material. The junction of the complementary plate 42 comprises the third metallic material.

[0071] The first heat exchange stage of the supplementary plate 42 is provided with a first supplementary cavity, in particular delimited by the heat exchange walls between the main fluid and the first cooling fluid of the supplementary plate 42. The second heat exchange stage of the supplementary plate 42 is provided with a second supplementary cavity, in particular delimited by the heat exchange walls between the main fluid and the second cooling fluid of the supplementary plate 42.

[0072] The main and complementary plates 40, 42 of each heat exchanger element 38 are stacked so that the first main 54 and complementary cavities form part of the first cooling fluid circuit 22, and so that the second main 56 and complementary cavities form part of the second cooling fluid circuit 24. In particular, the main and complementary plates 40, 42 of each heat exchanger element 38 are assembled, for example by brazing, to form the heat exchanger assembly 38.

[0073] Each heat exchanger element 38 comprises inlets 58b and outlets 58a for the first cooling fluid, each opening into a portion of the first cooling fluid circuit 22, and inlets 58d and outlets 58c for the second fluid, each opening into a portion of the second cooling fluid circuit 24. More specifically, each main and auxiliary plate 40, 42 comprises openings 58a, 58b forming the inlet and outlet for the first cooling fluid, such that each portion of the first cooling fluid circuit 22 communicates with the inlet 30 and outlet 32 ​​for the first cooling fluid. Similarly, each main and auxiliary plate 40, 42 comprises openings 58c, 58d forming the inlet and outlet for the second cooling fluid, such that each portion of the second cooling fluid circuit Cooling 24 communicates with inlet 34 and outlet 36 for the second cooling fluid.

[0074] Thus, the first cooling fluid circulates in the portion of the first cooling fluid circuit 22 formed by each heat exchanger element 38 between the first heat exchange stage 44 of the main plate 40 and the first heat exchange stage of the supplementary plate 42 of the heat exchanger element 38 concerned. In particular, the first cooling fluid circulates in the portion of the first cooling fluid circuit 22 from the opening forming an inlet 58b for the first cooling fluid of the heat exchanger element 38 concerned to the opening forming an outlet 58a for the first cooling fluid of the heat exchanger element 38 concerned.

[0075] Similarly, the second cooling fluid circulates in the portion of the second cooling fluid circuit 24 formed by each heat exchanger element 38 between the second heat exchange stage 48 of the main plate 40 and the second heat exchange stage of the supplementary plate 42 of the heat exchanger element 38 concerned. In particular, the second cooling fluid circulates in the portion of the second cooling fluid circuit 24 from the opening forming an inlet 58d for the second cooling fluid of the heat exchanger element 38 concerned to the opening forming an outlet 58c for the second cooling fluid of the heat exchanger element 38 concerned.

[0076] The first heat transfer occurs through the heat exchange walls 46 between the main fluid and the first cooling fluid. The second heat transfer occurs through the heat exchange walls 50 between the main fluid and the second cooling fluid.

[0077] A plurality of orifices 60 are formed in the junction 52 of each main plate 40. The orifices 60 are here distinct and formed regularly along the elongation direction of the junction 52 of the main plate 40. Alternatively, a single orifice 60 could be formed in the junction 52 of the main plate 40.

[0078] The orifices 60 are formed at a distance from the edges of the main plate 40.

[0079] The orifices 60 are through-holes and open on both sides of the plate main 40. The orifices 60 do not open into the first cooling fluid circuit 22. The orifices 60 do not open into the second cooling fluid circuit 24.

[0080] The orifices 60 allow to reduce a parasitic heat transfer taking place by conduction between the first cooling fluid circuit 22 and the second cooling fluid circuit 24 through the junction 52.

[0081] Advantageously, deflectors are formed in the first cooling fluid circuit 22 and in the second cooling fluid circuit 24, in particular on the heat exchange walls 46 between the main fluid and the first cooling fluid and on the heat exchange walls 50 between the main fluid and the second cooling fluid, to prevent over-velocities of the first and second cooling fluids. The deflectors here comprise pads 62a formed in the first cooling fluid circuit 22 and the second cooling fluid circuit 24, as well as deflecting walls 62b formed in the second cooling fluid circuit 24.

[0082] Advantageously, pads 64 to facilitate brazing are also formed in the second cooling fluid circuit 24, in particular to increase the stiffness of the second cooling fluid circuit 24.

[0083] Advantageously, each main and complementary plate 40, 42 includes rims 66, each extending an edge of a main or complementary plate 40, 42. Each rim 66 partially defines the spacing between two main and complementary plates 40, 42 of the heat exchanger 12.

[0084] Fig. 5 schematically represents a method for reducing heat exchange between first and second heat exchange stages 44, 48 of a main plate having a first heat exchange stage 44 with heat exchange walls between the main fluid and the first cooling fluid, a second heat exchange stage 48 with heat exchange walls between the main fluid and the second cooling fluid, and a junction 52 separating the first and second heat exchange stages 44, 48.

[0085] A plurality of orifices 60 are provided in Injunction 52 of the main plate. Thus, the heat exchange between the first and second heat exchange stages 44, 48 of the main plate is reduced.

[0086] In the examples described, the main fluid is a gas, and the first and second fluids are liquids. Alternatively, in another application, the main fluid and the first and second fluids could be liquids. Conversely, it is envisaged that the main fluid and the first and second fluids could be gases.

[0087] In the examples described, the main fluid is cooled by the first and second fluids. Alternatively, in another application, the main fluid could be heated by the first and second fluids.

Claims

1. Demands Heat exchanger (12) comprising a plurality of heat exchanger elements (38) comprising: - a main plate for a heat exchanger (40) having a first heat exchange stage (44) with heat exchange walls (46) between a main fluid and a first fluid, a second heat exchange stage (48) with heat exchange walls (50) between the main fluid and a second fluid, and a junction (52) separating the first and second heat exchange stages (44, 48), at least one orifice (60) being formed in the junction (52), - a supplementary plate for heat exchanger (42) having a first heat exchange stage with heat exchange walls between the main fluid and the first fluid, a second heat exchange stage with heat exchange walls between the main fluid and the second fluid, and a junction separating the first and second heat exchange stages of the supplementary plate (42), the main and complementary plates (40, 42) being stacked and assembled so that the first fluid is able to circulate between the first heat exchange stages (44) of the main and complementary plates (40, 42) in a first cooling fluid circuit (22), and so that the second fluid is able to circulate between the second heat exchange stages (48) of the main and complementary plates (40, 42) in a second cooling fluid circuit (24), the heat exchanger elements (38) being stacked so that the main fluid is able to circulate between two successive heat exchanger elements (38) of the stack, characterized in that deflectors (62a, 62b) are formed in the first cooling fluid circuit (22) and in the second cooling fluid circuit (24), the deflectors (62a, 62b) comprising pads (62a) formed in the first cooling fluid circuit (22) and in the second cooling fluid circuit (24), and deflector walls (62b) formed in the second cooling fluid circuit (24), pads (64) to facilitate brazing and increase the stiffness of the second circuit cooling fluid (24) being formed in the second cooling fluid circuit (24).

2. Heat exchanger according to claim 1, wherein the main fluid comprises a gas, in particular air.

3. Heat exchanger according to claim 1 or 2, wherein the first fluid comprises an engine coolant, the second fluid comprising a heat exchanger coolant (12).

4. Heat exchanger according to any one of claims 1 to 3, wherein the walls (46) of the first heat exchange stage (44) comprise a first metallic material, the walls (50) of the second heat exchange stage (48) comprise a second metallic material, the junction (52) comprises a third metallic material, in particular the first, second and third metallic materials being identical.

5. Heat exchanger according to any one of claims 1 to 4, wherein the first heat exchange stage (44) is provided with a first main cavity (54) configured to form at least in part the first cooling fluid circuit for the first fluid (22) when the main plate (40) is assembled with a supplementary heat exchanger plate (42) having a first supplementary cavity, the second heat exchange stage (48) being provided with a second main cavity (56) configured to form at least in part the second cooling fluid circuit for the second fluid (24) when the main plate (40) is assembled with the supplementary plate (42) having a second supplementary cavity.

6. Powertrain (2) for motor vehicle comprising at least one heat exchanger (12) according to any one of claims 1 to 5, a main supply circuit (6) of said heat exchanger (12) with main fluid, a first supply circuit (22) of said heat exchanger (12) with first fluid, and a second supply circuit (24) of said heat exchanger (12) with second fluid.

7. Powertrain (2) according to claim 6, comprising a heat engine equipped with a cylinder head (4) and a turbocharger configured to compress the main fluid and supply fluid main compressed the cylinder head (4), said heat exchanger (12) being configured to cool the main compressed fluid, the main supply circuit (6) being configured to supply said heat exchanger (12) with main compressed fluid to be cooled, and to supply the cylinder head (4) with cooled main compressed fluid.

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