Thermal management system for hybrid or electric vehicle

Abstract

The invention relates to a thermal management system for a hybrid or electric vehicle, comprising a reversible air conditioning circuit (10) comprising a compressor (12), a first heat exchanger (14), a second heat exchanger (16), a first refrigerant storage device (18), a first expansion member (20) and a two-fluid heat exchanger (22), which are jointly arranged on a circuit (11) of heat transfer fluid. The circuit (10) further comprises a first bypass branch (24) between a first bypass point (26) on the main circuit (LP) between the first heat exchanger (14) and the second heat exchanger (16) and a first junction point (28) on the main circuit (LP) between the first refrigerant storage device (18) and the first expansion member (20), the main circuit (LP) further comprises a second refrigerant storage (30) between the first heat exchanger (14) and the first bypass point (26). In addition to the two-fluid heat exchanger (22), the circuit (11) of the third heat transfer fluid comprises a fourth heat exchanger (32).

Description

Field of the Invention

[0001] The present invention relates to the field of motor vehicles, and more particularly to a thermal management circuit for hybrid or electric motor vehicles. Background Art

[0002] In electric and hybrid vehicles, the thermal management of the interior cabin is typically performed by a reversible air-conditioning circuit. Reversible means that the air-conditioning circuit can operate in a cooling mode to cool the air supplied to the interior cabin and can operate in a heat pump mode to heat the air supplied to the interior cabin. The reversible air-conditioning circuit can also include a branch line to manage the temperature of the battery of the electric or hybrid vehicle. Thus, the reversible air-conditioning circuit can be used to cool or even heat the battery. In the heat pump mode, thermal energy is obtained from the external air and transferred to the internal air flow, which is blown into the interior cabin to heat it.

[0003] It is known practice to use a refrigerant circuit that sequentially includes a compressor, an internal condenser, an expansion device, and an evaporator. The evaporator is used, for example, to cool the cockpit air. In addition, the circuit typically can also include a branch line that branches off to an evaporator-condenser (which acts as a condenser in the air-conditioning mode and as an evaporator in the heat pump mode) on the front face of the vehicle.

[0004] Therefore, one of the objectives of the present invention is to improve the performance of such a system in the air-conditioning mode while maintaining good performance in the heat pump mode. Summary of the Invention

[0005] One aspect of the present invention relates to a thermal management system for a hybrid or electric vehicle, the thermal management system including a reversible air-conditioning circuit through which a refrigerant circulates, the reversible air-conditioning circuit sequentially including, in the main refrigerant circuit: a compressor; a first heat exchanger arranged to exchange thermal energy, for example, directly or indirectly, with a first heat transfer fluid, the first heat transfer fluid being, for example, an internal air flow blown into the interior cabin of the vehicle; a second heat exchanger arranged to exchange thermal energy, for example, directly or indirectly, with a second heat transfer fluid, the second heat transfer fluid being, for example, an external air flow on the front face of the vehicle; a first refrigerant storage device, in particular for performing a gas / liquid separation function; a first refrigerant expansion member and a two-fluid heat exchanger, which are jointly arranged on a circuit for a third heat transfer fluid, the third heat transfer fluid being, for example, a heat transfer liquid,

[0006] The refrigerant circuit further includes a first branch line extending between a first bifurcation point on the main circuit and a first confluence point on the main circuit, the first bifurcation point being located between the first heat exchanger and the second heat exchanger, the first branch line being located between the first refrigerant storage device and the first expansion member, and the main circuit for the refrigerant further includes a second refrigerant storage device between the first heat exchanger and the first bifurcation point,

[0007] In addition to the said two-fluid heat exchanger, the circuit for the third heat transfer fluid further includes a fourth heat exchanger which is arranged to exchange thermal energy directly or indirectly with a fourth heat transfer fluid, such as an external air flow at the front face of the vehicle.

[0008] Due to the subcooling allowed by the first refrigerant storage device, the system enables the enthalpy of the fluid to be reduced when the fluid enters the evaporator, thereby reducing the performance of the system in air-conditioning mode. This aspect of the invention is also a novel and inexpensive way to achieve heat pump mode by using a two-fluid heat exchanger ("cooler"), which is also used to cool the battery in battery cooling mode. As a refrigerant evaporator, the third heat transfer fluid flowing through the two-fluid heat exchanger is passively cooled by an external heat exchanger (referred to as the fourth heat exchanger).

[0009] According to certain aspects of the invention, the above system includes one or more of the following features considered individually or in any technically possible combination:

[0010] - The first refrigerant storage device is integrated into the second heat exchanger, and the second heat exchanger includes a subcooling channel located downstream of the first refrigerant storage device.

[0011] - The refrigerant circuit includes a first three-way valve connecting the second refrigerant storage device, the second heat exchanger, and the first branch branch at a first confluence point.

[0012] - The two-fluid heat exchanger is connected to the compressor, and there is no other heat exchanger between the two-fluid heat exchanger and the compressor.

[0013] - The refrigerant circuit further includes a second refrigerant branch branch extending between a second bifurcation point and a second confluence point. The second bifurcation point is located on the main circuit between the second heat exchanger and the first expansion member, for example, between the first confluence point and the first expansion member. The second confluence point is located on the main circuit between the two-fluid heat exchanger and the compressor.

[0014] - The second branch branch includes a second expansion member and a fifth heat exchanger in the flow direction of the refrigerant, which is arranged to exchange thermal energy directly or indirectly with a fifth heat transfer fluid, especially such that the fifth heat exchanger can operate as a refrigerant evaporator when the system is in air-conditioning mode and dehumidification mode. The fifth heat transfer fluid is, for example, an internal air flow blown into the interior compartment of the vehicle.

[0015] - The refrigerant circuit further includes a third refrigerant branch branch extending between a third bifurcation point and a third confluence point. The third bifurcation point is located on the main circuit between the first refrigerant storage device and the first confluence point of the first branch branch. The third confluence point is located on the second branch branch between the fifth heat exchanger and the second confluence point of the second branch branch.

[0016] - The third branch line branch includes a stop valve.

[0017] - The second branch line branch includes a first check valve located between the third confluence point of the third branch line branch and the second confluence point of the second branch line branch.

[0018] - The main circuit includes a second check valve located between the first refrigerant storage device and the first confluence point of the first branch line branch.

[0019] - The second check valve is located between the third bifurcation point of the third branch line branch and the first confluence point of the first branch line branch.

[0020] - The system includes an internal air ventilation device in which the first heat exchanger is arranged.

[0021] - The circuit for the third heat transfer fluid includes a first heat transfer fluid circulation branch, the first heat transfer fluid circulation branch includes a first pump and a dual-fluid heat exchanger, the circuit for the third heat transfer fluid also includes a so-called "external" branch for the circulation of the third heat transfer fluid, the external branch includes the fourth heat exchanger, the upstream end of the external branch is connected to the downstream end of the first branch, and the downstream end of the external branch is connected to the upstream end of the first branch, in particular such that they together form a circulation circuit for the third heat transfer fluid.

[0022] - The first branch also includes an electric heating device, preferably upstream of the dual-fluid heat exchanger, preferably directly upstream.

[0023] - The circuit for the third heat transfer fluid includes a second branch for the circulation of the third heat transfer fluid, the upstream end of the second circulation branch is connected to the downstream end of the first branch, such as downstream of the dual-fluid heat exchanger, and the downstream end of the second branch is connected to the upstream end of the first branch, in particular such that they together form a circulation circuit for the third heat transfer fluid, and the second branch preferably does not include devices that are liable to significantly change the heat accumulated by the third heat transfer fluid.

[0024] - The circuit for the third heat transfer fluid includes a third branch for the circulation of the third heat transfer fluid, the third branch includes a second pump and a sixth heat exchanger, such as a "motor" type heat exchanger for heat exchange with the "motor" of the vehicle.

[0025] - The circuit for the third heat transfer fluid includes a fourth branch for the circulation of the third heat transfer fluid. The fourth branch includes a seventh heat exchanger, such as a "battery" type heat exchanger for heat exchange with the "battery" of the vehicle. The upstream end of the fourth branch is connected to the downstream end of the first branch, and the downstream end of the fourth branch is connected to the upstream end of the first branch through a fifth branch for the circulation of the third heat transfer fluid, particularly such that they together form a circuit for the circulation of the heat transfer fluid, for example to allow the electric heating device to heat the third heat transfer fluid flowing in the seventh heat exchanger, or for example to allow the cooling of the third heat transfer fluid flowing in the seventh heat exchanger when the two-fluid heat exchanger is enabled.

[0026] - The upstream end of the fourth branch is connected to the downstream end of the third branch, and the downstream end of the fourth branch is connected to the upstream end of the third branch, particularly such that they together form a circuit for the circulation of the third heat transfer fluid, for example to allow the third heat transfer fluid flowing in the seventh heat exchanger to be heated by recovering heat in the sixth heat exchanger.

[0027] - The circuit for the third heat transfer fluid includes a sixth branch for the circulation of the third heat transfer fluid. The upstream end of the sixth branch is connected to the downstream end of the third branch, and the downstream end of the sixth branch is connected to the upstream end of the external branch, particularly such that the third branch, the sixth branch, and the external branch together form a circuit for the circulation of the third heat transfer fluid, particularly allowing the "passive" cooling of the third heat transfer fluid flowing in the sixth heat exchanger.

[0028] - The circuit for the third heat transfer fluid includes an expansion vessel, such as located on the external branch.

[0029] - The circuit for the third heat transfer fluid includes a second three-way valve, which connects the downstream end of the first branch, the upstream end of the second branch, and the upstream end of the external branch, and is configured to allow the third heat transfer fluid to flow between the first branch and the second branch or between the first branch and the external branch. The first branch is connected, for example, via a seventh branch.

[0030] - The circuit for the third heat transfer fluid includes a third check valve on an eighth branch. The eighth branch connects the upstream end of the first branch and the downstream end of the fourth branch, and is located downstream of the fourth bifurcation point where the seventh branch bifurcates and upstream of the fourth convergence point where the third branch and the fourth branch intersect.

[0031] - The circuit for the third heat transfer fluid includes a third three-way valve that connects the downstream end of the fourth branch, the upstream end of the fifth branch, and the upstream end of the third branch, and is configured to allow the third heat transfer fluid to flow between the fourth branch and the fifth branch or between the fourth branch and the third branch.

[0032] - The circuit for the third heat transfer fluid includes a fourth three-way valve that connects the downstream end of the third branch, the upstream end of the fourth branch, and the upstream end of the sixth branch, so as to allow the third heat transfer fluid to flow between the third branch and the fourth branch or between the third branch and the sixth branch.

[0033] - The main circuit includes a third expansion member between the first bifurcation point of the first branch line and the second heat exchanger, such that when the system is in the heat pump mode, the second heat exchanger can operate as a refrigerant evaporator, for example, in combination with a two-fluid heat exchanger or otherwise, for example, when the system is in the heat pump mode, the two-fluid heat exchanger itself also operates as a refrigerant evaporator.

[0034] - The third expansion member is integrated into a first three-way valve that connects the second refrigerant storage device, the second heat exchanger, and the first branch at the first confluence point.

[0035] Another aspect of the present invention relates to a method for operating a system manufactured as described in any one of the preceding claims, wherein, in a first heat pump mode, the first heat exchanger operates as a refrigerant condenser or cooler, and the two-fluid heat exchanger operates as a refrigerant evaporator.

[0036] According to certain aspects of the present invention, the above method includes one or more of the following features considered individually or in any technically possible combination:

[0037] - In a second heat pump mode, the first heat exchanger and the second heat exchanger operate as refrigerant condensers or coolers, and the two-fluid heat exchanger operates as a refrigerant evaporator.

[0038] - In a first air conditioning mode, the first heat exchanger and the second heat exchanger operate as refrigerant condensers or coolers, and the fifth heat exchanger operates as a refrigerant evaporator.

[0039] - In a vehicle battery cooling mode, the first heat exchanger and the second heat exchanger operate as refrigerant condensers or coolers, and the two-fluid heat exchanger operates as a refrigerant evaporator.

[0040] - In the combined air-conditioning and vehicle battery cooling mode, the first heat exchanger and the second heat exchanger operate as refrigerant condensers or coolers, and the dual-fluid heat exchanger and the fifth heat exchanger operate as refrigerant evaporators.

[0041] - In the vehicle compartment dehumidification mode, the first heat exchanger operates as a refrigerant condenser or cooler, and the fifth heat exchanger operates as a refrigerant evaporator.

[0042] - In the third heat pump mode, the first heat exchanger operates as a refrigerant condenser or cooler, and the second heat exchanger operates as a refrigerant evaporator.

[0043] - In the fourth heat pump mode, the first heat exchanger operates as a refrigerant condenser or cooler, the second heat exchanger and the dual-fluid heat exchanger operate as refrigerant evaporators, and the third heat transfer fluid flowing through the dual-fluid heat exchanger is heated, for example, in the fourth heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Further features and advantages of these aspects of the present invention will become apparent by reading the following detailed description, which is provided by way of illustrative example and with reference to the accompanying drawings briefly described below for understanding.

[0045] Figure 1 is a schematic diagram showing an example of an air-conditioning circuit equipped in a thermal management system manufactured according to an aspect of the present invention.

[0046] Figure 2 is a view through Figure 1 an example of a heat transfer fluid circuit of a dual-fluid heat exchanger.

[0047] Figure 3 is a schematic diagram showing Figure 1 the circuit in the first heat pump mode.

[0048] Figure 4 is a schematic diagram showing Figure 1 the circuit in the battery cooling mode.

[0049] Figure 5 is a schematic diagram showing Figure 1 the circuit in the combined dehumidification and heat pump mode.

[0050] Figure 6 is a schematic diagram showing an example of an air-conditioning circuit equipped in a thermal management system manufactured according to another aspect of the present invention.

[0051] Figure 7 is a schematic diagram showing Figure 6 the circuit in the heat pump mode.

[0052] Figure 8 is a schematic diagram showing that the circuit of Figure 6 is in another heat pump mode.

[0053] Figure 9 is a schematic diagram showing that the circuit of Figure 6 is in a combined heat pump and dehumidification mode. DETAILED DESCRIPTION

[0054] In the remainder of the specification, elements having the same structure or similar functions will be denoted by the same reference numerals.

[0055] In the following description, the expression "the first element upstream of the second element" means that the first element is placed before the second element with respect to the flow or travel direction of the fluid. Similarly, the expression "the first element downstream of the second element" means that the first element is placed after the second element with respect to the flow or travel direction of the fluid under discussion. When appropriate, the flow direction is defined by the arrow of the compressor or the arrow of the heat pump.

[0056] The term "branch" refers here to a part of a circuit that is open at both ends and includes only elements arranged in series.

[0057] Also note that the term "battery" should not be understood to refer to all the batteries of a vehicle, but rather to a plurality of batteries.

[0058] The term "battery" should be understood to mean any energy storage entity capable of releasing energy in electrical form.

[0059] In the drawings, the pipes through which the refrigerant moves are represented by thick lines, and the pipes through which the heat transfer fluid does not move are represented by thin lines.

[0060] Note that the terms "first", "second", "third" are simple naming conventions and do not imply a specific number of components. Thus, one can refer to a "fifth" heat exchanger without there necessarily being five or more heat exchangers in the circuit. For example, the circuit can have fewer than five heat exchangers.

[0061] As shown in the respective drawings, the present invention relates to a thermal regulation system. This is, for example, a thermal management system for a motor vehicle. In this case, it is an electric or hybrid motor vehicle including an electric motor that provides a power torque to the drive wheels of the vehicle. The electric motor is supplied with current at least by a battery called a traction battery. During vehicle operation, the electric motor and the battery are prone to generating heat.

[0062] More specifically as Figure 1 shown, the system includes a first circuit (or refrigerant circuit) 10 for air conditioning, in which the refrigerant circulates, as Figure 1as shown, and a second circuit 11 for a heat transfer fluid through which the heat transfer fluid circulates, as Figure 2 shown.

[0063] The heat transfer fluid is, for example, a heat transfer liquid such as water containing an antifreeze, in particular ethylene glycol water, or any other suitable heat transfer fluid. The refrigerant is, for example, a hydrofluorocarbon such as R-134a or R1234yf or R744.

[0064] As Figure 1 shown, the circuit 10 is a reversible air-conditioning circuit in which the refrigerant circulates.

[0065] The refrigerant circuit 10 includes, in the direction of circulation of the refrigerant, in the main refrigerant circuit LP, in sequence: a compressor 12, a first heat exchanger 14 arranged to exchange thermal energy with a first heat transfer fluid, a second heat exchanger 16 arranged to exchange thermal energy with a second heat transfer fluid, a first refrigerant storage device 18, in particular for performing a gas / liquid separation function, a first refrigerant expansion member 20, and a two-fluid heat exchanger 22, which are all arranged together on the circuit 11 for a third heat transfer fluid.

[0066] The first refrigerant storage device 18 is generally referred to as a "receiver". It may contain a refrigerant desiccant. It performs a gas / liquid separation function such that the fluid leaving it is a liquid.

[0067] The first expansion member 20 is generally an electronic fluid expansion valve or an "electronic expansion valve".

[0068] The two-fluid heat exchanger 22 is directly connected to the compressor 12 in this case, i.e., there is no other heat exchanger between the two-fluid heat exchanger 22 and the compressor 12.

[0069] The two-fluid heat exchanger 22 is configured to allow heat exchange between the refrigerant circulating in the air-conditioning circuit 10 and the third heat transfer fluid circulating in the circuit 11 for the third heat transfer fluid, without mixing between the heat transfer fluid and the refrigerant. This type of heat exchanger is generally referred to by those skilled in the art as a "cooler", as Figure 1 shown in the example. More generally, it is a liquid / liquid type heat exchanger capable of exchanging thermal energy between two different liquids.

[0070] The first heat exchanger 14 arranged to exchange thermal energy with the first heat transfer fluid is, in this case, an internal condenser of the ventilation device 56 that blows internal air into the interior compartment of the vehicle. Thus, in this example, the first heat transfer fluid is the internal air flow Fi blown into the interior compartment of the vehicle.

[0071] The first heat exchanger 14 is more generally a heat exchanger that operates as a refrigerant condenser or cooler.

[0072] The second heat exchanger 16 arranged to exchange thermal energy with a second heat transfer fluid is in this case a condenser on the front face of the vehicle. Thus, in this example, the second heat transfer fluid is the external air flow Fe on the front face of the vehicle. More generally, the second heat exchanger 16 is a heat exchanger arranged to function as a refrigerant condenser or cooler.

[0073] In this case, the first refrigerant storage device 18 is integrated into the second heat exchanger 16, which includes a refrigerant subcooling passage downstream.

[0074] The circuit 10 for the refrigerant also includes a first branch line 24 extending between a first branch point 26 on the main circuit LP located between the first heat exchanger 14 and the second heat exchanger 16 and a first confluence point 28 on the main circuit LP located between the first refrigerant storage device 18 and the first expansion member 20.

[0075] The first branch line 24 enables the second heat exchanger 16 to be bypassed, so as to convey the refrigerant to the dual-fluid heat exchanger 22, as will be explained in more detail later with reference to Figure 3 More detailed explanation.

[0076] The said main circuit LP for the refrigerant also includes a second refrigerant storage device 30 located between the first heat exchanger 14 and the said first branch point 26.

[0077] The second refrigerant storage device 30 is commonly referred to as a "receiver". It may contain a refrigerant desiccant. It performs a gas / liquid separation function such that the fluid leaving it is a liquid.

[0078] In addition to the said dual-fluid heat exchanger 22, the circuit 11 for the third heat transfer fluid itself also includes a fourth heat exchanger 32, which is arranged to exchange thermal energy directly or indirectly with a fourth heat transfer fluid.

[0079] In this case, the fourth heat exchanger 32 is a radiator ("external" heat exchanger) on the front face of the vehicle, and the fourth heat transfer fluid is the external air flow (Fe) on the front face of the vehicle in this example. More generally, this is a heat exchanger for cooling or heating the third heat transfer fluid, that is, for cooling or heating the heat transfer liquid flowing through the fourth heat exchanger 32.

[0080] For example, in this case, the third heat transfer fluid is ethylene glycol water or any other suitable type of heat transfer liquid.

[0081] The refrigerant circuit 10 further includes a second refrigerant branch line 34 extending between a second branch point 36 and a second confluence point 38. The second branch point 34 is located on the main circuit LP between the second heat exchanger 26 and the first expansion member 20, for example, between the first confluence point 26 and the first expansion member 20, and the second confluence point 38 is located on the main circuit LP between the two-fluid heat exchanger 22 and the compressor 12.

[0082] The first branch line 24 includes, in the flow direction of the refrigerant, a second expansion member 40 and a fifth heat exchanger 42, which are arranged to exchange thermal energy directly or indirectly with a fifth heat transfer fluid, in particular such that the fifth heat exchanger 42 can operate as a refrigerant evaporator when the system is in the air conditioning mode and the dehumidification mode. In this example, the fifth heat transfer fluid is an internal air flow (Fi) blown into the interior compartment of the vehicle. In fact, the fifth heat exchanger 42 is typically an evaporator integrated into the internal air ventilation device 56. More generally, it is a heat exchanger for evaporating the refrigerant flowing therein.

[0083] The second expansion member 40 is typically an electronic fluid expansion valve or an "electronic expansion valve".

[0084] The refrigerant circuit 10 further includes a third refrigerant branch line 44 extending between a third branch point 46 and a third confluence point 48. The third branch point 46 is located on the main circuit LP between the first refrigerant storage device 18 and the first confluence point 28 of the first branch line 24, and the third confluence point 48 is located on the second branch line 34 between the fifth heat exchanger 42 and the second confluence point 38 of the second branch line 34.

[0085] The refrigerant circuit 10 is also equipped with different types of valves or check valves.

[0086] The refrigerant circuit 10 includes a first three-way valve 33 that connects the second refrigerant storage device 30, the second heat exchanger 16, and the first branch line 24 at the first confluence point 26. This first three-way valve 33 allows the refrigerant to flow from the first heat exchanger 14 towards the second heat exchanger 16 or towards the first branch line 24. As an alternative, two shut-off valves are used, one on each branch downstream of the first branch point 26.

[0087] The third branch line 44 includes a shut-off valve 50 but does not include a heat exchanger in this example.

[0088] The second branch line 34 includes a first check valve 52 located between the first confluence point of the second branch line 34 and the third confluence point 48 of the third branch line 44.

[0089] The main circuit LP includes a second check valve 54, which is located between the first refrigerant storage device 18 and the first confluence point 28 of the first branch line 24, and more specifically, between the third bifurcation point 46 of the third branch line 44 and the first confluence point 28 of the first branch line 24.

[0090] Reference will be made Figures 3 to 5 to explain in more detail Figure 1 the main operating mode of the circuit.

[0091] Figure 2 A possible heat transfer liquid circuit for the third heat transfer fluid passing through the double-fluid heat exchanger 22 is shown by way of example.

[0092] The circuit 11 for the third heat transfer fluid includes a first heat transfer fluid flow branch B1, which includes a first pump 58 and a double-fluid heat exchanger 22. The circuit 11 for the third heat transfer fluid also includes a so-called "external" branch BE for the flow of the third heat transfer fluid, and the external branch BE includes the fourth heat exchanger 32.

[0093] To form a flow circuit for the third heat transfer fluid, the upstream end of the external branch BE is connected to the downstream end of the first branch B1, and the downstream end of the external branch is connected to the upstream end of the first branch B1. In this way, when the first pump 58 is enabled, the heat transfer liquid flows through the double-fluid heat exchanger 22 and the fifth heat exchanger 32, thereby allowing passive heating of the heat transfer liquid and thus allowing passive heating of the refrigerant passing through the double-fluid heat exchanger.

[0094] The circuit 11 for the third heat transfer fluid also includes a second branch B2 for the flow of the third heat transfer fluid. The upstream end of the second flow branch B2 is connected to the downstream end of the first branch B1, for example, downstream of the double-fluid heat exchanger 22, and the downstream end of the second branch B2 is connected to the upstream end of the first branch B1, such that they together form a flow circuit for the third heat transfer fluid.

[0095] The second branch B2 preferably does not include means that are likely to significantly change the heat accumulated by the first heat transfer fluid.

[0096] This arrangement of the first and second branches B1, B2 allows the third heat transfer fluid to flow in a circuit through the first pump 58, the electric heating device 60, and the double-fluid heat exchanger 22, so that when the electric heating device 60 is enabled, this active heating of the refrigerant can be carried out. Preferably, the electric heating device 60 is directly located upstream of the double-fluid heat exchanger 22. For example, this heating mode of the refrigerant is useful when the external temperature is too low to heat the refrigerant. This minimum temperature will depend on the type of refrigerant used.

[0097] The circuit 11 for the third heat transfer fluid includes a third branch B3 and a fourth branch B4 for the circulation of the third heat transfer fluid.

[0098] The third branch B3 includes a second pump 62 and a sixth heat exchanger 66, such as a "motor" type heat exchanger for heat exchange with the motor of the vehicle.

[0099] The fourth branch B4 includes a seventh heat exchanger 68, such as a "battery" type heat exchanger for heat exchange with the battery of the vehicle. The upstream end of the fourth branch B4 is connected to the downstream end of the first branch B1, and the downstream end of the fourth branch B4 is connected to the upstream end of the first branch B1 through a fifth branch B5 for the circulation of the third heat transfer fluid, especially such that they together form a circuit for the circulation of the heat transfer fluid, for example to allow the electric heating device 60 to heat the third heat transfer fluid flowing in the seventh heat exchanger 68, or for example to allow the third heat transfer fluid flowing in the seventh heat exchanger 68 to be cooled when the dual-fluid heat exchanger 22 is enabled, thereby cooling the vehicle battery.

[0100] Here, the upstream end of the fourth branch B4 is connected to the downstream end of the third branch B3, and the downstream end of the fourth branch B4 is connected to the upstream end of the third branch B3, especially such that they together form a circuit for the circulation of the third heat transfer fluid, for example to allow the third heat transfer fluid flowing in the seventh heat exchanger 68 to be heated by recovering heat in the sixth heat exchanger 66, i.e., in the motor of the vehicle (such as an electric motor or power electronics).

[0101] The circuit 11 for the third heat transfer fluid further includes a sixth branch B6 for the circulation of the third heat transfer fluid. The upstream end of the sixth branch is connected to the downstream end of the third branch B3, and the downstream end of the sixth branch B6 is connected to the upstream end of the external branch BE, especially such that the third branch B3, the sixth branch B6, and the external branch together form a circuit for the circulation of the third heat transfer fluid, especially to allow "passive" cooling of the third heat transfer fluid flowing in the sixth heat exchanger 66.

[0102] In addition, the circuit 11 for the heat transfer fluid here includes various valves or check valves for guiding the circulation of the heat transfer fluid.

[0103] The circuit 11 for the third heat transfer fluid includes a "second" three-way valve 74, a "third" three-way valve 76, and a "fourth" three-way valve 78.

[0104] The second three-way valve 74 is connected to the downstream end of the first branch B1, the upstream end of the second branch B2, and the upstream end of the external branch BE, and is configured to allow a third heat transfer fluid to flow between the first branch B1 and the second branch B2 or between the first branch B1 and the external branch BE. The first branch B1 is connected, for example, via the seventh branch B7.

[0105] The third three-way valve 76 is connected to the downstream end of the fourth branch B4, the upstream end of the fifth branch B5, and the upstream end of the third branch B3, and is configured to allow a third heat transfer fluid to flow between the fourth branch B4 and the fifth branch B5 or between the fourth branch B4 and the third branch B3.

[0106] The fourth three-way valve 78 is connected to the downstream end of the third branch B3, the upstream end of the fourth branch B4, and the upstream end of the sixth branch B6 so as to allow a third heat transfer fluid to flow between the third branch B3 and the fourth branch B4 or between the third branch B3 and the sixth branch B6.

[0107] Furthermore, a “third” check valve 80 is arranged on the eighth branch B8 connecting the upstream end of the first branch B1 and the downstream end of the fourth branch B4, downstream of the fourth bifurcation point 82 where the seventh branch B7 bifurcates and upstream of the fourth confluence point 84 where the third branch B3 and the fourth branch B4 intersect. This check valve 80 allows, for example, circulation through the second pump 62, the sixth heat exchanger 66, and the seventh heat exchanger 68, while also allowing the heat transfer fluid to flow from the first branch B1 to the fourth branch B4.

[0108] The flow of the heat transfer fluid from the first branch B1 to the seventh branch B7 is achieved here by closing the downstream end of the fourth branch B4 at the third three-way valve 76.

[0109] It should also be noted that the circuit 11 for the third heat transfer fluid includes an expansion vessel 72 located on the external branch BE. Alternatively, the expansion vessel is located elsewhere in the circuit 11 for the third heat transfer fluid.

[0110] Reference Figures 3 to 5 shows various operating modes of the reversible air-conditioning circuit.

[0111] In Figure 3 the refrigerant circuit 10 operates in the first heat pump mode.

[0112] The first three-way valve 33 closes the flow towards the second heat exchanger 16 and ensures the flow from the first heat exchanger 14 towards the first branch line 24. The second expansion member 40 is closed, preventing the flow towards the fifth heat exchanger 42. In contrast, the first expansion member 20 is partially opened so that the refrigerant expands before reaching the dual-fluid heat exchanger 22. The refrigerant is then conveyed towards the compressor 12 due to the check valve 52. If necessary, the shut-off valve 50 is opened to convey the charge from the condenser towards the active circuit.

[0113] Thus, the refrigerant circuit 10 forms a closed circuit for the continuous circulation of the refrigerant through the compressor 12 to the first heat exchanger 14 operating as a refrigerant condenser or cooler, through the second storage device 30 of the receiver type, through the first expansion member 20, and through the dual-fluid heat exchanger 22 operating as a refrigerant evaporator, thereby heating the refrigerant. To transfer the required heat to the refrigerant, a third heat transfer fluid, for example, moves towards the external radiator 32 to collect thermal energy from the external air flow Fe, as previously described above with reference to Figure 2 Explanation.

[0114] In summary, this first heat pump mode uses the battery cooler 22 ("dual-fluid heat exchanger") as an evaporator.

[0115] In Figure 4 the battery cooling mode shown, the first three-way valve 33 cuts off the flow towards the first branch line 24 and ensures the flow from the first heat exchanger 14 towards the second heat exchanger 16. The shut-off valve 50 is closed. The second expansion member 40 is closed and the first expansion member 20 is partially opened to perform the expansion of the refrigerant.

[0116] The refrigerant circuit 10 thus forms an active circuit for the refrigerant, and the refrigerant successively circulates through the compressor 12, through the first heat exchanger 14 operating as a refrigerant condenser or cooler, through the second storage device 30 of the receiver type, through the second heat exchanger 16 operating as a refrigerant condenser or cooler, through the first expansion member 20, and through the dual-fluid heat exchanger 22 operating as a refrigerant evaporator, thereby heating the refrigerant. The refrigerant thus cools the third heat transfer fluid, thereby allowing the battery to be cooled by the third heat transfer fluid flowing through the "battery" seventh heat exchanger 68. Removing heat from the battery in the first heat exchanger 1' and the second heat exchanger 16 together enables maximizing the battery cooling capacity.

[0117] In an operating mode not shown, this operating mode differs from the Figure 2 mode in that the first expansion member 20 is closed and the second expansion member 40 is partially opened to evaporate the refrigerant in the fifth heat exchanger 42, obtaining an interior vehicle air conditioning mode with a large cooling capacity.

[0118] In another operating mode (not shown), this operating mode is different from Figure 2 the mode in that both the first expansion member 20 and the second expansion member 40 are partially opened to evaporate the refrigerant in the dual-fluid heat exchanger 22 and the fifth heat exchanger 42, obtaining a combined battery cooling and internal air-conditioning mode.

[0119] Figure 5 A combined dehumidification and heat pump mode is shown.

[0120] The first three-way valve closes the flow towards the first branch line 24 and ensures the flow from the first heat exchanger 14 towards the second heat exchanger 16. The first expansion member 20 and the second expansion member 40 are partially opened to expand the refrigerant and cause the dual-fluid heat exchanger 22 and the fifth heat exchanger 42 to operate as refrigerant evaporators.

[0121] If necessary, the shut-off valve 50 is opened to convey the charge from the condenser towards the active circuit.

[0122] Both the first heat exchanger 14 and the second heat exchanger 16 operate as refrigerant condensers (or coolers). As in Figure 3 the operating mode, the dual-fluid heat exchanger collects the heat in the refrigerant, which is released in the first heat exchanger 14 to heat the interior compartment of the vehicle. In addition, the fifth heat exchanger 42 allows the air to be dehumidified by lowering the temperature of the internal air passing through it and condensing some of the moisture contained in this internal air.

[0123] Another dehumidification mode (not shown) is different from Figure 5 the mode only in that the first expansion member 20 is closed, thus preventing the refrigerant from flowing through the dual-fluid heat exchanger (or "cooler") 22.

[0124] Figure 6 A second embodiment of the refrigerant circuit according to another aspect of the present invention is shown, which is different from Figure 1 the circuit only in that it includes a third expansion member 70 located between the first bifurcation point 26 of the first branch line 24 and the second heat exchanger 16.

[0125] In this example, the third expansion member 70 is integrated into the first three-way valve 33. Alternatively, the third expansion member 70 is independent of the first three-way valve 26.

[0126] The third expansion member 70 is of any suitable type. For example, it is an electronic fluid expansion valve or an "electronic expansion valve".

[0127] The third expansion member 70 allows the refrigerant reaching the second heat exchanger 16 to undergo expansion, and thus allows the second heat exchanger to operate as a refrigerant evaporator. The refrigerant flows through the second heat exchanger in the same direction as when the second heat exchanger 16 is used as a refrigerant condenser (or cooler), so that when the system is in the heat pump mode, the second heat exchanger 16 can operate as a refrigerant evaporator, for example in combination with the two-fluid heat exchanger 22 or otherwise, such as when the two-fluid heat exchanger 22 itself operates as a refrigerant evaporator when the system is in the heat pump mode.

[0128] Figure 6 The loop allows reference to Figures 3 to 5 the operating modes shown and described, and also allows reference to Figures 7 to 9 other operating modes described.

[0129] In Figure 7 it, the first three-way valve 33 closes the first branch line 24 and allows the refrigerant to flow from the first heat exchanger towards the second heat exchanger 16. The third expansion member 70 is partially open. The first expansion member 20 and the second expansion member 40 are closed. The shut-off valve 50 is open. The refrigerant circuit thus ensures that the refrigerant flows in a circuit from the compressor 12 towards the first heat exchanger 14, the second heat exchanger 16, and then back to the compressor. The first heat exchanger 16 operates as a refrigerant condenser (or cooler), while the second heat exchanger 16 operates as a refrigerant evaporator. This is the heat pump mode, which is an alternative mode to the heat pump mode in which the two-fluid heat exchanger 22 is used as an evaporator.

[0130] Figure 8 shows another heat pump mode corresponding to the Figure 3 and Figure 7 combination of operating modes.

[0131] Compared with Figure 7 the refrigerant circuit 10 of Figure 8 is characterized in that the first expansion member 20 is partially open to allow the refrigerant to flow towards the two-fluid heat exchanger 22 while expanding the refrigerant in the first expansion member 20, and in that the shut-off valve 50 is closed.

[0132] The refrigerant circuit 10 thus forms a circuit in which the refrigerant flows from the compressor 12 towards the first heat exchanger 14 and then towards the second heat exchanger 16, and then the refrigerant flows towards the two-fluid heat exchanger 22.

[0133] The first heat exchanger 1' operates as a refrigerant condenser (or cooler), while the second heat exchanger 14 and the two-fluid heat exchanger 22 operate as evaporators.

[0134] More specifically, the second heat exchanger 16 operates as an evaporator with respect to the external air Fe, and the two-fluid heat exchanger 22 operates as an evaporator with respect to the third heat transfer fluid. As explained with reference to Figure 2 the third heat transfer fluid is passively heated when flowing through the external radiator 32 (or the fourth heat exchanger) or is actively heated when flowing through the electric heating device 60.

[0135] Figure 8 The embodiment of makes it possible to increase the heating power in the heat pump mode.

[0136] Finally, Figure 9 shows an operating mode that combines the Figure 8 increased power heat pump mode with the dehumidification mode. The refrigerant circuit 10 is different from Figure 8 in that the second expansion member 40 is partially opened to allow the refrigerant to flow towards the fifth heat exchanger 42 while causing the refrigerant to undergo expansion in the second expansion member. In this way, a part of the refrigerant from the second exchanger 16 branches towards the first expansion member 20 and the two-fluid heat exchanger 22, while the other part of the refrigerant reaching the second bifurcation point 36 flows towards the second expansion member 40 and then towards the fifth heat exchanger 42 before returning to the compressor 12. Therefore, the fifth heat exchanger 42 operates in parallel with the two-fluid heat exchanger 22 as a refrigerant evaporator, and the two-fluid heat exchanger 22 also operates as a refrigerant evaporator 22. Thus, the internal air ventilation device 16 dehumidifies the internal air fluid, which is first cooled in the fifth heat exchanger 42 and then heated in the first heat exchanger 16.

Claims

1. A thermal management system for a hybrid or electric vehicle, the thermal management system comprising a reversible air-conditioning circuit (10) through which a refrigerant circulates, the reversible air-conditioning circuit (10) being in a main refrigerant circuit (LP) along the flow direction of the refrigerant comprising: a compressor (12); a first heat exchanger (14) arranged to exchange thermal energy with a first heat transfer fluid, such as an internal air flow (Fi) blown into the interior compartment of the vehicle, directly or indirectly; a second heat exchanger (16) arranged to exchange thermal energy with a second heat transfer fluid, such as an external air flow (Fe) on the front face of the vehicle, in particular such that the second heat exchanger (16) can operate as a refrigerant cooler or condenser when the system is in air-conditioning mode; a first refrigerant storage device (18) particularly for performing a gas / liquid separation function; a first refrigerant expansion member (20) and a two-fluid heat exchanger (22), the first refrigerant expansion member (20) and the two-fluid heat exchanger (22) being jointly arranged on a circuit (11) for a third heat transfer fluid, such as a heat transfer liquid, the refrigerant circuit (10) further comprising a first branch (24) extending between a first branch point (26) on the main circuit (LP) and a first confluence point (28) on the main circuit (LP), the first branch point (26) being located between the first heat exchanger (14) and the second heat exchanger (16), the first branch (24) being located between the first refrigerant storage device (18) and the first expansion member (20), in particular such that the two-fluid heat exchanger (22) can operate as a refrigerant evaporator when the system is in heat pump mode, the main circuit (LP) for the refrigerant further comprising a second refrigerant storage device (30) between the first heat exchanger (14) and the first branch point (26), in addition to the two-fluid heat exchanger (22), the circuit (11) for the third heat transfer fluid further comprises a fourth heat exchanger (32) arranged to exchange thermal energy with a fourth heat transfer fluid, such as an external air flow (Fe) on the front face of the vehicle.

2. The system according to claim 1, wherein, the first refrigerant storage device (18) is integrated into the second heat exchanger (16), and the second heat exchanger (16) comprises a subcooling channel downstream of the first refrigerant storage device (18).

3. The system according to claim 1 or 2, wherein, The refrigerant circuit (10) further includes a second refrigerant branch line (34) extending between a second branch point (36) and a second confluence point (38). The second branch point (36) is located on the main circuit (LP) between the second heat exchanger (16) and the first expansion member (20), for example, between the first confluence point (28) and the first expansion member (20), and the second confluence point (38) is located on the main circuit (LP) between the dual-fluid heat exchanger (22) and the compressor (12).

4. The system according to claim 3, wherein, the second branch line (34) includes a second expansion member (40) and a fifth heat exchanger (42) in the flow direction of the refrigerant. The fifth heat exchanger (42) is arranged to exchange thermal energy directly or indirectly with a fifth heat transfer fluid, particularly such that the fifth heat exchanger (42) can operate as a refrigerant evaporator when the system is in the air conditioning mode and the dehumidification mode. The fifth heat transfer fluid is, for example, an internal air flow (Fi) blown into the interior compartment of the vehicle.

5. The system according to claim 3 or 4, wherein, the refrigerant circuit (10) further includes a third refrigerant branch line (44) extending between a third branch point (46) and a third confluence point (48). The third branch point (46) is located on the main circuit (LP) between the first refrigerant storage device (18) and the first confluence point (28) of the first branch line (24), and the third confluence point (48) is located on the second branch line (34) between the fifth heat exchanger (42) and the second confluence point (38) of the second branch line (34).

6. The system according to any one of the preceding claims, wherein, the circuit (11) for the third heat transfer fluid includes a first heat transfer fluid flow branch (B1). The first heat transfer fluid flow branch (B1) includes a first pump (58) and the dual-fluid heat exchanger (22). The circuit (11) for the third heat transfer fluid further includes a so-called "external" branch (BE) for the flow of the third heat transfer fluid. The external branch (BE) includes the fourth heat exchanger (32). The upstream end of the external branch (BE) is connected to the downstream end of the first branch (B1), and the downstream end of the external branch (BE) is connected to the upstream end of the first branch (B1), particularly such that they together form a flow circuit for the third heat transfer fluid.

7. The system according to claim 6, wherein, the first branch (B1) further includes an electric heating device (60), preferably upstream of the dual-fluid heat exchanger (22), preferably directly upstream.

8. The system according to claim 6 or 7, wherein, The circuit (11) for the third heat transfer fluid includes a second branch (B2) for the circulation of the third heat transfer fluid, the upstream end of the second circulation branch (B2) being connected to the downstream end of the first branch (B1), for example downstream of the two-fluid heat exchanger (22), and the downstream end of the second branch (B2) being connected to the upstream end of the first branch (B1), in particular such that they together form a circulation circuit for the third heat transfer fluid, and the second branch (B2) preferably does not include means liable to significantly modify the heat accumulated by the third heat transfer fluid.

9. The system according to any one of the preceding claims, wherein, the main circuit (LP) includes a third expansion member (70) located between the first bifurcation point (34) of the first branch (24) and the second heat exchanger (16), in particular such that the second heat exchanger (16) can operate as a refrigerant evaporator when the system is in the heat pump mode, for example in combination with the two-fluid heat exchanger (22) or otherwise, for example when the system is in the heat pump mode the two-fluid heat exchanger (22) itself also operates as a refrigerant evaporator.

10. A method for operating a system manufactured as claimed in any one of the preceding claims, wherein, in a first heat pump mode, the first heat exchanger (14) operates as a refrigerant condenser or cooler, and the two-fluid heat exchanger (22) operates as a refrigerant evaporator.

11. The method according to claim 10, wherein, the system is the system according to any one of the preceding claims considered in conjunction with claim 4, and wherein, in a first air conditioning mode, the first heat exchanger (14) and the second heat exchanger (16) operate as refrigerant condensers or coolers, and the fifth heat exchanger (42) operates as a refrigerant evaporator.

12. The method according to claim 10 or 11, wherein, in a vehicle battery cooling mode, the first heat exchanger (14) and the second heat exchanger (16) operate as refrigerant condensers or coolers, and the two-fluid heat exchanger (22) operates as a refrigerant evaporator.

13. The method according to any one of claims 10 to 12, wherein, the system is the system according to any one of the preceding claims considered in conjunction with claim 9, and wherein, in a second heat pump mode, the first heat exchanger (14) operates as a refrigerant condenser or cooler, and the second heat exchanger (16) operates as a refrigerant evaporator.

14. The method according to claim 13, wherein, in a third heat pump mode, the first heat exchanger (14) operates as a refrigerant condenser or cooler, and the second heat exchanger (16) and the two-fluid heat exchanger (22) operate as refrigerant evaporators, and the third heat transfer fluid flowing through the two-fluid heat exchanger (22) is heated, for example in the fourth heat exchanger (32).

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