Main plate for heat exchanger, heat exchanger element, heat exchanger, powertrain and associated method

Abstract

This heat exchanger main plate (40) is provided with a first heat exchange stage (44) provided with walls (46) for heat exchange between a main fluid and a first fluid, a second heat exchange stage (48) provided with walls (50) for heat exchange 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 hole being formed in the junction (52).

Description

[0001] MAIN PLATE FOR HEAT EXCHANGER, HEAT EXCHANGER ELEMENT, HEAT EXCHANGER, POWERTRAIN AND ASSOCIATED METHOD.

[0002] Technical field

[0003] The technical field of the present invention is that of plate heat exchangers . In particular, the present invention relates to a heat exchanger main plate, 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 of reducing heat exchanges between first and second heat exchange stages of a heat exchanger main plate.

[0004] Prior art

[0005] A powertrain for a motor vehicle may comprise a turbocharger and a heat engine supercharged by the turbocharger and provided with a cooling circuit. It is advantageous to cool the air leaving the turbocharger, for example to a temperature of around 180°C, before injecting it into an engine cylinder head, for example at a temperature of around 45°C.

[0006] The heat engine cooling circuit may be insufficient to cool the air leaving the turbocharger, particularly in compact powertrain architectures .

[0007] Explanation of the invention

[0008] The aim of the present invention is therefore to overcome some or all of the aforementioned drawbacks, and in particular to provide a compact, high- performance heat exchanger

[0009] The invention concerns a main plate for a heat exchanger provided with a first heat exchange stage provided with walls for heat exchange between a main fluid and a first fluid, a second heat exchange stage provided with walls for heat exchange between the main fluid and a second fluid, and a junction separating the first and second heat exchange stages.

[0010] At least one hole is formed in the junction.

[0011] 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. The main plate provided with the first and second heat exchange stages enables a first heat exchange to take place between the main fluid and the first fluid in the first heat exchange stage, and a second heat exchange to take place between the main fluid and the second fluid in the second heat exchange stage. This makes the main plate suitable for compact, successive heat exchangers .

[0012] The main plate junction conducts heat.

[0013] Said hole formed in the main plate junction makes it possible to reduce heat exchanges between the first and second heat exchange stages through the junction, in particular to reduce conductive heat exchanges 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.

[0014] Preferably, the first and second heat exchange stages of the main plate are formed by stamping the main plate.

[0015] Preferably, the first fluid is different from the second fluid.

[0016] Preferably, the second fluid is at a temperature strictly lower than the temperature of the first fluid.

[0017] According to a first design, said hole formed in the junction of the main plate is through-going.

[0018] Alternatively, the hole formed in the main plate junction is blind.

[0019] Advantageously, a plurality of separate holes are formed in the main plate junction.

[0020] The main fluid may comprise a gas, in particular air. The main fluid may consist of a gas, in particular air.

[0021] The first fluid may be a kind of engine coolant (cooling fluid). The first fluid may consist of an engine coolant.

[0022] The second fluid may be a kind of heat exchanger coolant. The second fluid may consist of a heat exchanger coolant.

[0023] Advantageously, the first heat exchange stage is provided with an inlet and an outlet for the first fluid, while the second heat exchange stage is provided with an inlet and an outlet for the second fluid. Optionally, the walls of the first heat exchange stage comprise a first metallic material. The walls of the first heat exchange stage can 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 can be formed entirely of the second metallic material.

[0025] Optionally, the junction comprises a third metallic material. The junction can be formed entirely of the third metal material

[0026] Advantageously, the first, second and third metallic materials are identical. The first heat exchange stage, the second heat exchange stage and the main plate junction can be one-piece. In particular, the first heat exchange stage can be integral with the junction and the junction can be integral with the second heat exchange stage.

[0027] The first heat exchange stage can be provided with a first main indentation 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 complementary first indentation.

[0028] The second heat exchange stage can be provided with a second main indentation 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 indentation.

[0029] Another object of the present invention is a heat exchanger element comprising a main heat exchanger plate as previously defined and a complementary heat exchanger plate provided with a first heat exchange stage provided with heat exchange walls between the main fluid and the first fluid, a second heat exchange stage provided 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 complementary plate, the main and complementary plates being stacked and assembled so that the first fluid is able to circulate between the first heat exchange stages of the main and complementary plates, and so that the second fluid is able to circulate between the second heat exchange stages of the main and complementary plates . 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.

[0030] The junction of the complementary plate can be identical to the junction of the main heat exchanger plate.

[0031] Advantageously, the first main indentation of the first heat exchange stage of the main plate and the first complementary indentation of the first heat exchange stage of the complementary plate are joined together by brazing. Advantageously, the second main indentation of the second heat exchange stage of the main plate and the second complementary indentation of the second heat exchange stage of the complementary plate are joined together by brazing.

[0032] Advantageously, brazing is carried out by depositing a bead of material on the first and second main and complementary indentations .

[0033] Another object of the present invention is a heat exchanger comprising a plurality of heat exchanger elements as previously defined stacked so that the main fluid is able to circulate between two successive heat exchanger elements of the stack.

[0034] Another object of the present invention is 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.

[0035] Advantageously, the powertrain comprises a heat engine provided with a cylinder head and a turbocharger configured to compress the main fluid and supply the cylinder head with compressed main fluid, 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. Another object of the present invention is a method of reducing heat exchanges between first and second heat exchange stages of a main plate for a heat exchanger provided with a first heat exchange stage provided with walls for heat exchange between a main fluid and a first fluid, a second heat exchange stage provided with walls for heat exchange 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 hole in the junction of the main plate.

[0036] Brief description of the drawings

[0037] Further aims, 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 appended drawings on which:

[0038] [Fig. 1 ] schematically illustrates a powertrain according to an embodiment of the invention;

[0039] [Fig. 2] schematically illustrates a heat exchanger according to an embodiment of the invention;

[0040] [Fig. 3] schematically illustrates a stack of heat exchanger elements according to an embodiment of the invention;

[0041] [Fig. 4] schematically illustrates a main plate for a heat exchanger according to an embodiment of the invention; and

[0042] [Fig. 5] illustrates a method according to an embodiment of the invention.

[0043] Detailed description

[0044] Figure 1 shows schematically a powertrain 2 for a motor vehicle, comprising a cylinder head 4 integral with a cylinder block, an air intake circuit 6 supplying air to the cylinder head 4, and a combustion gas exhaust circuit 8. The air intake circuit 6 comprises an air inlet advantageously fitted with an air filter (not shown) capable of filtering the air coming from the air inlet, a compressor 10 capable of increasing the mass flow rate of the air coming from the air inlet and a plate heat exchanger 12 capable of reducing the temperature of the air coming from the compressor 10, the cooled air being injected into the cylinder head 4. The air intake circuit 6 is the main supply circuit for the heat exchanger 12. Heat exchanger 12 is, for example, a charged air cooler.

[0045] The combustion gas exhaust circuit 8 comprises a turbine 14 capable to expand the exhaust gases coming from the cylinder head 4, and a catalytic converter 16 capable to reduce the pollutant emissions of the exhaust gases coming from the turbine 14.

[0046] The powertrain 2 comprises a shaft 18 on which the compressor 10 and turbine 14 are mounted to form a turbocharger.

[0047] Figure 2 shows a schematic diagram of heat exchanger 12. Heat exchanger 12 comprises a main fluid circuit 20, through which flows a main fluid to be cooled, in this case air compressed by compressor 10, and first and second coolant circuits, 22 and 24 respectively, through which flow first and second coolants (cooling fluids) .

[0048] The heat exchanger 12 comprises an inlet 26 and an outlet 28 for the main fluid, which communicate with the main fluid circuit 20.

[0049] Similarly, the heat exchanger 12 comprises an inlet 30 and an outlet 32 for the first coolant, which communicate with the first coolant circuit 22, and an inlet 34 and an outlet 36 for the second coolant, which communicate with the second coolant circuit 24.

[0050] Inlets 30 and 34, on the one hand, and outlets 32 and 36, on the other, for the first and second coolants are respectively connected to first and second circuits supplying the powertrain 2 with the first and second coolant (not shown) .

[0051] According to the embodiment of the heat exchanger 12, as shown by way of example in Figure 2, the outlet 32 for the first coolant is arranged between the inlet 26 for the main fluid and the inlet 30 for the first coolant, and the outlet 36 for the second coolant is arranged between the inlet 30 for the first coolant and the inlet 34 for the second coolant. In addition, the inlet 34 for the second coolant is arranged between the outlet 36 for the second coolant and the outlet 28 for the main fluid.

[0052] The main fluid flows from the inlet 26 for the main fluid to the outlet 28 for the main fluid, in heat exchange relationship with the first and second coolants in the first and second coolant circuits 22 and 24, so that a first heat transfer takes place between the main fluid and the first coolant, which flows from the inlet 30 for the first coolant to the outlet 32 for the first coolant, and then a second heat transfer takes place between the main fluid and the second coolant, which flows from the inlet 34 for the second coolant to the outlet 36 for the second coolant.

[0053] The first coolant comprises, for example, an engine coolant from powertrain 2, and here consists of the engine coolant. The second coolant comprises, for example, a heat exchanger 12 coolant, and here consists of the heat exchanger 12 coolant.

[0054] The main fluid entering heat exchanger 12 is at a strictly higher temperature than the first coolant, which is at a strictly higher temperature than the second coolant. For example, the air compressed by compressor 10 is at a temperature of around 180°C, the engine coolant is at a temperature of around 110°C, and the coolant in heat exchanger 12 is at a temperature of around 30°C.

[0055] As illustrated more visibly in Figure 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. The heat exchanger elements 38 are stacked so that the main fluid flows between each pair of successive heat exchanger elements 38 in the stack, in particular in a direction transverse to the stacking direction.

[0056] Referring to Figure 4, each main plate 40 is provided with a first heat exchange stage 44 with heat exchange walls 46 between the main fluid and the first coolant, a second heat exchange stage 48 with heat exchange walls 50 between the main fluid and the second coolant, and a junction 52 separating the first and second heat exchange stages 44, 48.

[0057] The first and second heat exchange stages 44, 48 are, for example, formed by stamping the main plate 40.

[0058] The junction 52 forms a strip of material separating the first and second heat exchange stages 44, 48.

[0059] The walls 46 of the first heat exchange stage 44 of the main plate 40 comprise a first metallic material, such as copper, aluminum, stainless steel or steel. The walls 50 of the second heat exchange stage 48 of the main plate 40 comprise a second metallic material, such as copper, aluminum, stainless steel or steel. The junction 52 of the main plate 40 comprises a third metallic material, such as copper, aluminum, stainless steel or steel.

[0060] Advantageously, the first, second and third metallic materials are identical. The first heat exchange stage 44 of the main plate 40 is provided with a first main indentation 54, in particular delimited by the heat exchange walls 46 between the main fluid and the first coolant of the main plate 40. The second heat exchange stage 48 of the main plate 40 is provided with a second main indentation 56, in particular delimited by the heat exchange walls 50 between the main fluid and the second coolant of the main plate 40.

[0061] In a similar way, each complementary plate 42 is provided with a first heat exchange stage provided with heat exchange walls between the main fluid and the first coolant, a second heat exchange stage provided with heat exchange walls between the main fluid and the second coolant, and a junction separating the first and second heat exchange stages of the complementary plate 42.

[0062] 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 metal material. The junction of the complementary plate 42 comprises the third metal material The first heat exchange stage of the complementary plate 42 is provided with a first complementary indentation, in particular delimited by the heat exchange walls between the main fluid and the first coolant of the complementary plate 42. The second heat exchange stage of the complementary plate 42 is provided with a second complementary indentation, in particular delimited by the heat exchange walls between the main fluid and the second coolant of the complementary plate 42.

[0063] The main and complementary plates 40, 42 of each heat exchanger element 38 are stacked so that the first main and complementary indentations 54 form part of the first coolant circuit 22, and so that the second main and complementary indentations 56 form part of the second coolant circuit 24. In particular, the main and complementary plates 40, 42 of each heat exchanger element 38 are joined, for example by brazing, to form the heat exchanger assembly 38. Each heat exchanger element 38 comprises inlets 58b and outlets 58a for the first coolant, each opening into the portion of the first coolant circuit 22, and inlets 58d and outlets 58c for the second fluid, each opening into the portion of the second coolant circuit 24. More precisely, each main and complementary plate 40, 42 comprises openings 58a, 58b forming the inlet and outlet for the first coolant so that each part of the first coolant circuit 22 communicates with the inlet 30 and outlet 32 for the first coolant. Similarly, each main and complementary plate 40, 42 comprises openings 58c, 58d forming the inlet and outlet for the second coolant so that each part of the second coolant circuit 24 communicates with the inlet 34 and outlet 36 for the second coolant.

[0064] In this way, the first coolant circulates in the part of the first coolant 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 complementary plate 42 of the heat exchanger element 38 concerned. In particular, the first coolant flows in the portion of the first coolant circuit 22 from the opening forming an inlet 58b for the first coolant of the relevant heat exchanger element 38 to the opening forming an outlet 58a for the first coolant of the relevant heat exchanger element 38.

[0065] Likewise, the second coolant circulates in the portion of the second coolant 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 complementary plate 42 of the heat exchanger element 38 concerned. In particular, the second coolant flows in the portion of the second coolant circuit 24 from the opening forming an inlet 58d for the second coolant of the relevant heat exchanger element 38 to the opening forming an outlet 58c for the second coolant of the relevant heat exchanger element 38.

[0066] The first heat transfer takes place through the heat exchange walls 46 between the main fluid and the first coolant. The second heat transfer takes place through the heat exchange walls 50 between the main fluid and the second coolant.

[0067] A plurality of holes 60 are formed in the junction 52 of each main plate 40. In this case, the holes 60 are separate and formed regularly along the direction of elongation of the junction 52 of the main plate 40. Alternatively, a single hole 60 could be formed in the junction 52 of the main plate 40.

[0068] The holes 60 are spaced from the edges of the main plate 40.

[0069] The holes 60 are through-holes and open out on either side of the main plate 40. Ports 60 do not open into the first coolant circuit 22. Ports 60 do not open into the second coolant circuit 24.

[0070] The holes 60 reduce parasitic heat transfer by conduction between the first coolant circuit 22 and the second coolant circuit 24 through the junction 52. Advantageously, deflectors are formed in the first coolant circuit 22 and in the second coolant circuit 24, in particular on the heat exchange walls 46 between the main fluid and the first coolant and on the heat exchange walls 50 between the main fluid and the second coolant, to prevent overspeeding of the first and second coolant. The deflectors comprise studs 62a formed in the first coolant circuit 22 and the second coolant circuit 24, and deflector walls 62b formed in the second coolant circuit 24.

[0071] Advantageously, studs 64 to facilitate brazing are also formed in the second coolant circuit 24, in particular to increase the stiffness of the second coolant circuit 24.

[0072] Advantageously, each main and complementary plate 40, 42 respectively comprises flanges 66 each extending an edge of a main or complementary plate 40, 42. Each flange 66 partly defines the spacing between two main and complementary plates 40, 42 of the heat exchanger 12.

[0073] Figure 5 shows schematically a method of reducing heat exchange between first and second heat exchange stages 44, 48 of a main plate provided with a first heat exchange stage 44 provided heat exchange walls between the main fluid and the first coolant, a second heat exchange stage 48 provided with heat exchange walls between the main fluid and the second coolant, and a junction 52 separating the first and second heat exchange stages 44, 48.

[0074] A plurality of holes 60 are formed in the junction 52 of the main plate. This reduces heat exchange between the first and second heat exchange stages 44, 48 of the main plate.

[0075] 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 . Alternatively, it is envisaged that the main fluid and the first and second fluids are gases

[0076] 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

CLAIMS1. Main plate for a heat exchanger (40) provided with a first heat exchange stage (44) provided with walls (46) for heat exchange between a main fluid and a first fluid, a second heat exchange stage (48) provided with walls (50) for heat exchange between the main fluid and a second fluid, and a junction (52) separating the first and second heat exchange stages (44, 48), characterized in that at least one hole (60) is formed in the junction (52).

2. Main plate for a heat exchanger (40) according to claim 1 , wherein the main fluid comprises a gas, in particular air.

3. Main plate for a heat exchanger (40) according to claim 1 or 2, wherein the first fluid comprises an engine coolant, the second fluid comprising a coolant of the heat exchanger ( 12).

4. Main plate for a heat exchanger (40) according to any of the preceding claims, 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. Main plate for a heat exchanger (40) according to any of the preceding claims, wherein the first heat exchange stage (44) is provided with a first main indentation (54) configured to form at least in part a first circuit for the first fluid (22) when the main plate (40) is assembled with a complementary heat exchanger (42) plate provided with a complementary first indentation, the second heat exchange stage (48) being provided with a second main indentation (56) configured to form at least in part a second circuit for the second fluid (24) when the main plate (40) is assembled with the complementary plate (42) provided with a second complementary indentation.

6. Heat exchanger element (38) comprising a main heat exchanger (40) plate according to any one of the preceding claims and a complementary heat exchanger plate (42) provided with a first heat exchange stage provided with heat exchange walls between the main fluid and the first fluid, a second heat exchange stage provided with heat exchange walls between the mainfluid and the second fluid, and a junction separating the first and second heat exchange stages of the complementary plate (42), the main and complementary plates (40, 42) being stacked and assembled so that the first fluid is capable to flow between the first heat exchange stages (44) of the main and complementary plates (40, 42), and so that the second fluid is capable to flow between the second heat exchange stages (48) of the main and complementary plates (40, 42) .

7. Heat exchanger ( 12) comprising a plurality of heat exchanger elements (38) according to the preceding claim stacked so that the main fluid is capable to circulate between two successive heat exchanger elements (38) of the stack.

8. Powertrain (2) for a motor vehicle comprising at least one heat exchanger ( 12) according to the preceding claim, a main supply circuit (6) for the main fluid to the said heat exchanger ( 12), a first supply circuit (22) for the first fluid to the said heat exchanger ( 12), and a second supply circuit (24) for the second fluid to the said heat exchanger ( 12) .

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

10. Method of reducing heat exchange between first and second heat exchange stages (44, 48) of a main plate for a heat exchanger (40) provided with a first heat exchange stage (44) provided with walls (46) for heat exchange between a main fluid and a first fluid, a second heat exchange stage (48) provided with walls (50) for heat exchange between the main fluid and a second fluid, and a junction (52) separating the first and second heat exchange stages (44, 48), characterized in that it comprises the provision of at least one hole (60) in the junction (52) of the main plate (40).

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