Thermal system for a motor vehicle
Patent Information
- Application Number
- PCT/EP2026/054523
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-02-20
- Filing Date
- 2026-02-19
- Publication Date
- 2026-08-27
Smart Images
Figure EP2026054523_27082026_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE: Thermal system of a motor vehicle
[0003] The invention relates to a thermal system for a motor vehicle.
[0004] The invention also relates to a motor vehicle equipped with such a thermal system.
[0005] A motor vehicle cooling system, or thermal system, must allow different circulations of the coolant so as to adapt to different conditions of use of the vehicle, for example different heating or cooling needs of the passenger compartment and / or components of the powertrain, in particular the electric powertrain, while minimizing the energy consumption of the vehicle.
[0006] To this end, a vehicle cooling system, or thermal system, may include separate loops of heat transfer fluid circulation adapted to the different components requiring thermal regulation. This optimizes the thermal management of each circuit, closely matching its specific heating and cooling needs. In this way, such thermal regulation aims to ensure the components operate at their nominal temperature while also maintaining the passenger compartment's set temperature.
[0007] To that end,
[0008] - in a first set of operating conditions for the thermal system, a cooling fluid circulating in a first loop can be isolated from a cooling fluid circulating in a second loop, the thermal requirement being notably different from one loop to the other, and
[0009] - in a second set of conditions of use of the thermal system, the same cooling fluid can circulate freely in the first and second loops of the circuit in order to achieve a heat transfer from one loop to the other.
[0010] Thus, in the first set of operating conditions, a vehicle's cooling system may include cooling loops with different temperatures. For example, in an electric vehicle, there may be a first low-temperature coolant loop (for example, at a temperature between 10°C and 60°C) intended for the thermal management of an electric motor, the battery and electronic components (inverter, DC / DC voltage converter, etc.), and a second higher-temperature coolant loop (for example, at a temperature between 65°C and 80°C) intended for the thermal management of the passenger compartment.
[0011] The thermal system must also be able to manage a pressure difference between the first and second loops when these two loops are isolated from each other. In particular, in a configuration where the thermal system is equipped with only one expansion vessel, overpressure can develop in a fluid circulation loop that is not connected to the expansion vessel. Indeed, using a single expansion vessel for several cooling loops can create significant problems due to pressure variations in at least one of the loops, and the temperature variation in each loop, which causes the circulating fluid to expand. At this point, a loop not connected to an expansion vessel may lack a means of absorbing this expansion, resulting in increased pressure in the loop as the fluid expands, which tends to make thermal management difficult.Similarly, the contraction of the liquid volume leads to a decrease in loop pressure, with the risk of creating a cavitation phenomenon, particularly generated at the level of a pump used to circulate the loop.
[0012] The aim of the invention is to provide a thermal system that overcomes the above drawbacks and improves upon existing prior art cooling circuits. In particular, the invention enables the implementation of a reliable and efficient thermal system that allows the fluid circulation loops of a thermal system to operate optimally during the various phases of operation.To this end, the invention relates to a thermal system for a vehicle comprising a first subset of conduits forming a first circulation loop of a cooling fluid in particular through an electric motor and / or a power battery, a second subset of conduits forming a second circulation loop of a cooling fluid in particular through a heat exchanger and / or an electric heating element, a third subset of conduits forming a third circulation loop of a cooling fluid in particular through a radiator and / or an expansion tank, and an interconnection branch comprising conduits arranged between the first loop and at least one of the second and third loops.The system of the invention is particular in that it comprises a bidirectional sealing means disposed at the level of the interconnection branch, and in that said bidirectional sealing means comprising a first flow path of the cooling fluid and a second flow path of the cooling fluid shaped such that the flow of the cooling fluid is carried out respectively according to:.
[0013] - a first direction going from the first loop to the second loop, without limited flow, to achieve heat exchange between the first and second loops and
[0014] - a second direction opposite to the first direction going from the second loop to the third loop, with a limited flow rate in order to achieve a depressurization of the second loop so that a volume of expanded fluid from the second loop is able to be discharged to the expansion vessel.
[0015] The system may also include the following features, taken separately or in combination:
[0016] - said bidirectional sealing means comprises a main body in which a non-return valve is disposed, a first chamber defining the first flow path for a fluid between first and second orifices of the body connecting the second subset of conduits to the first and / or third subset of conduits;
[0017] - the non-return valve includes a ball, a means of returning the ball against a seat defined by the first chamber, the ball being able to move in said first chamber between open and closed positions allowing a flow of the cooling fluid through the first flow path;
[0018] - said bidirectional sealing means includes a pressure switch in fluidic relationship with the first chamber for said second flow path of the cooling fluid;
[0019] - said bidirectional sealing means includes a pressure switch for said second flow path of the cooling fluid, the pressure switch being separate from the body and connecting the second subset of conduits to the first and / or third subset of conduits by parallel branches connected to the interconnecting branches;
[0020] - said bidirectional sealing means includes a second body defining the second flow path for a fluid between first and second orifices of the second body connecting the second subset of conduits to the first and / or third subset of conduits via the pressure switch;
[0021] - the bidirectional sealing means comprises a secondary chamber in which the pressure switch is disposed, the secondary chamber having a separating plate provided with an opening through which a movable element of the pressure switch extends, and a means of returning the movable element against the separating plate in order to seal the opening, the separating plate separating the secondary chamber into upstream and downstream secondary chambers;
[0022] - said means of returning the moving element is a spring having a higher spring rate than said means of returning the ball;
[0023] - the moving element comprises a rod connected at its ends to upstream and downstream discs, the upstream disc being disposed in the upstream secondary chamber and connected to the separation plate by a return means which exerts a force returning the downstream disc to rest against the separation plate;
[0024] - the body comprises a conical part forming the seat, the conical part being extended by a cylindrical part closed at each of its ends by walls having respectively the first and second orifices;
[0025] - the wall with the first opening includes a perforated disc;
[0026] - the perforated disc comprises an inner cylinder and an outer cylinder, the cylinders being coaxial with each other and with respect to the first opening, the cylinders being connected to each other by straight and radial partitions delimiting channels through which the fluid is able to circulate, the inner cylinder forming a seat against which the ball is able to come to rest;
[0027] - the body includes a passage connecting the upstream secondary chamber to the first chamber by passing through the wall;
[0028] - the body includes an internal tube connecting the downstream secondary chamber to the opening, the internal tube partly defining the seat against which the ball is able to come to rest.
[0029] According to the invention, the thermal system may comprise a first set of components, among which
[0030] - an electric motor,
[0031] - a battery,
[0032] - thermal resistance,
[0033] - a cooler connected to an air conditioning circuit in the passenger compartment of a motor vehicle,
[0034] - a radiator,
[0035] and in that the battery and the electric motor are arranged in the first loop,
[0036] and in that the thermal resistance and the cooler are arranged in the second loop,
[0037] and in that the radiator and the expansion tank are arranged in the third loop.
[0038] In one embodiment, the thermal system further comprises a single expansion vessel connected to the first loop and / or the third loop via conduits, and to the second loop via said bidirectional sealing means such that an increase in pressure in conduits of the second loop causes a transfer of a quantity of fluid to the expansion vessel by a change of state of said bidirectional sealing means.
[0039] The invention further relates to a motor vehicle equipped with a thermal system having in whole or in part the aforementioned characteristics.
[0040] The attached drawings represent, by way of example, embodiments of a thermal system according to the invention, and of a component of the average bidirectional sealing type:
[0041] - [Fig.1] schematically represents a thermal system comprising a bidirectional sealing means, according to a first embodiment of the invention;
[0042] - [Fig.2] represents a first embodiment of a bidirectional sealing means taken in isolation, according to the invention;
[0043] - [Fig.3] represents an implementation of two independent heat transfer fluid circulation loops in a thermal system comprising the bidirectional sealing means according to an embodiment of the invention; - [Fig.4] represents an implementation of two heat transfer fluid circulation loops in fluidic relationship in a thermal system comprising the bidirectional sealing means allowing a first flow path, according to the invention;
[0044] - [Fig.5] represents said bidirectional closing means of [Fig. 2] according to the mode of operation of [Fig.4], according to the invention;
[0045] - [Fig.6] represents an implementation of two independent loops of heat transfer fluid circulation in a thermal system comprising the bidirectional closing means in a state of depressurization of the second loop, according to the invention;
[0046] - [Fig.7] represents said bidirectional closing means of [Fig. 2] according to the mode of operation of [Fig.6], according to the invention;
[0047] - [Fig.8] illustrates an embodiment of an element of said bidirectional sealing means according to the invention;
[0048] Figure 9 schematically represents a thermal system comprising a bidirectional sealing means, according to a second embodiment of the invention. An embodiment of a motor vehicle according to the invention is described below with reference to Figures 1 to 9. The motor vehicle is a motor vehicle of any type, in particular a passenger car or a commercial vehicle. The motor vehicle may be a combustion engine vehicle, an electric vehicle, or a hybrid vehicle. In the embodiment illustrated below, the motor vehicle is equipped with an electric powertrain.
[0049] The motor vehicle includes a first assembly comprising components including an electric motor 11, a battery 12, a cooler 13 connected to an air conditioning system of a passenger compartment of the motor vehicle, a thermal resistor 14, and a radiator 15.
[0050] In the remainder of this document, the term "motor 11" is used to refer to the electric motor itself, as well as various components associated with and located near the motor, such as current converters and a charger. In other words, the term "motor 11" encompasses a set of components dedicated to the operation of motor 11, including the electric traction chain comprising one or more electric motors and inverters and / or one or more converters and / or one or more chargers.
[0051] In the remainder of this document, a thermal system 1 is defined, comprising the first assembly. Thermal system 1 manages the thermal performance of the motor 11, the battery 12, the cooler 13, and the heating element 14, notably through heat exchange at the radiator 15.
[0052] In the embodiment presented below, the thermal system 1 further includes a first pump 41 and a second pump 42 enabling the generation of a circulation of heat transfer fluid in the conduits of the second set.
[0053] With reference to Figure 1, a thermal system 1 is described, further comprising a second assembly including conduits 22, 23, 25, 26, 27 and connectors 21, 24, 28 for connecting more than two conduits together. The radiator 15 is a vehicle cooling radiator: air passing through the radiator 15 cools the heat transfer fluid circulating in the conduits of the second assembly. The thermal system 1 further comprises a third assembly 30 including a four-way solenoid valve 31 and a three-way solenoid valve 32, the solenoid valves 31 and 32 being connected to conduits of the second assembly. The thermal system 1 according to the invention further comprises an expansion vessel 50.
[0054] In the remainder of this document, the term "chamber" or "degassing chamber" may also be used to refer to an expansion vessel, also called a "manifold." A chamber in a thermal system is pressurized and serves to create sufficient pressure at the inlet of each water pump in the system to prevent cavitation. Indeed, if the pressure at a pump is too low, cavitation can occur, which is the formation of vapor bubbles in a liquid following a sudden drop in pressure. These vapor bubbles implode abruptly when the pressure increases or when they encounter a wall. The implosion of bubbles in a wall area of the pump creates a violent impact that can damage the pump. Furthermore, the bubbles created during cavitation make the fluid compressible, which reduces the pump's performance.
[0055] Advantageously, as shown in Figure 1, the expansion vessel 50 can be a circulating type vessel, that is to say the vessel 50 has a first inlet nozzle for the heat transfer fluid located in its upper part, and a second outlet nozzle for the fluid located at its lowest point.
[0056] Advantageously, the thermal system 1 comprises a bidirectional closing means 7 according to the invention and:
[0057] - a first subset of conduits forming a first loop B1 for circulating a cooling fluid, and
[0058] - a second subset of conduits forming a second loop B2 for circulating a cooling fluid, the second loop B2 being separate from the first loop B1,
[0059] the first orifice 46 of the valve being connected to the first loop B1 by a conduit 26, and
[0060] the second orifice 47 of the valve being connected to the second loop B2 by a conduit 27 of the second loop B2.
[0061] Figure 3 represents a winter operating mode of the thermal system 1, in which, through loop B1, the battery 12 is heated by the heat generated by the components of the electric traction chain 11 and, through loop B2, the passenger compartment is heated by the heat pump 13.
[0062] In other words, to implement such a winter operating mode, the solenoid valves 31, 32 and the pumps 41, 42 are controlled to create a heat transfer fluid circulation comprising:
[0063] - a first loop B1 of heat transfer fluid circulation with a heat transfer fluid temperature between 10°C and 50°C to heat the battery, and
[0064] - a second loop B2 of heat transfer fluid circulation to heat the passenger compartment, using the calories generated by the electrical resistance 14 and the heat exchange at the level of the cooler 13, operating in evaporator mode of the heat pump, the first and second loops being connected by means of a bidirectional closing means 7 according to the invention.
[0065] In the described embodiment, a connector 21 links a conduit 22 of the second loop B2 to the conduit 23 of the first loop B1. Similarly, the connector 24 links the conduit 26 of the second loop B2 to the conduit 25 of the first loop B1.
[0066] Without implementation of the invention, depending on the power of each pump 41, 42, and the pressure losses induced by the circuit elements, a quantity of cooling fluid circulating in the second loop B2 could exit the second loop B2 via conduit 23 and connector 21, then enter the first loop B1 via conduit 22. Since the mass of heat transfer fluid is necessarily conserved in each of the loops B1, B2, a quantity of heat transfer fluid from the second loop B2 could then exit through conduit 27 to flow into the first loop B1 via connector 24 and conduits 26 and then 25. However, a mixture of cooling fluids at different temperatures between the two loops B1 and B2 is undesirable and can reduce the thermal performance of the thermal system 1.
[0067] In order for the two heat transfer fluid circulation loops B1 and B2 to operate independently, i.e., without heat transfer fluid between the two loops, a bidirectional shut-off means 7 according to the invention is disposed between the two loops B1 and B2; in particular, said bidirectional shut-off means 7 is disposed between
[0068] - the conduit 26 itself connected to the loop B1, upstream of the pump 42, via the connector 24 and
[0069] - the conduit 27 itself connected to the loop B2, in particular upstream of the pump 41, via a connector 28.
[0070] The bidirectional sealing means 7 according to the invention is described below with reference to figures 2, 5, 7 and 8.
[0071] The bidirectional shut-off means 7 according to the invention comprises a body 41, preferably cylindrical, inside which a non-return valve 40 is disposed. The cylindrical body 41 defines a first chamber 44 and includes a first orifice 46 and a second orifice 47. The first orifice 46 is fluidly connected to the first loop B1 via a conduit 26 connected to the connector 24. The second orifice 47 is fluidly connected to the second loop B2 via a conduit 27 connected to the connector 28. The first and second orifices 46 and 47 form connecting flanges onto which the conduits 26 and 27 are respectively assembled. The second subset of conduits is thus, via said bidirectional shut-off means 7, connected to the first and / or the third subset of conduits.
[0072] More particularly, the body 41 includes a conical part 122 forming the seat 143, the conical part being extended by a cylindrical part 123 closed at each of its ends by walls 124, 125 having respectively the first and second orifices 46, 47.
[0073] The chamber 44 is made by boring the body 41 in such a way that a passage is defined for a fluid, along a first direction 7A illustrated in Figure 5, between the first orifice 46 and a second orifice 47 of said bidirectional sealing means 7.
[0074] The check valve 40 includes a ball 42 and a means 51 for returning the ball 42 against a seat 143 defined by the first chamber. When the ball 42 is against the seat 143, the fluid passage along direction 7A is closed, so that there is no fluid flow. The ball 42 is in this case in a closed position 42B, illustrated in Figure 2.
[0075] In another position, called the open position, the ball 42 is moved away from the seat 143, so that it occupies an open position 42A, as illustrated in Figure 5. Thus, in this open position, a passage for a fluid is created such that fluid flow is possible from the first loop B1 to the second loop B2. In this open position, the ball 42 rests against a perforated disk 30 which comprises an inner cylinder 31 and an outer cylinder 32, as shown in Figure 8. The inner and outer cylinders 31, 32 are coaxial with each other and with respect to the first opening 46. The cylinders can be connected to each other by straight radial partitions 33, thus defining channels 34 through which the fluid is able to flow.In the open position 42A, the ball 42 is preferably arranged to rest against the inner cylinder 31, which forms a cylindrical seat against which the ball 42 is able to rest for the purpose of the flow of the cooling fluid through the first flow path 7A, as can be seen in Figures 4 and 5.
[0076] According to a first embodiment of said bidirectional sealing means 7, the pressure switch 70 is in fluidic relationship with the first chamber 44 in order to realize the second flow path 7B of the cooling fluid, in particular via the connection 24.
[0077] According to an alternative embodiment illustrated in Figure 9, the bidirectional shut-off means 7 comprises a pressure switch 170 for the second flow path 7B of the cooling fluid, the pressure switch 170 being separate from the body 41 in which only the non-return valve 40 is housed. The pressure switch 170 enables fluid connection of the second subset of conduits with the first and / or the third subset of conduits via the venting branch formed by conduits 16 and 17. The venting branch is parallel to the interconnecting branch formed by conduits 16 and 17, which are respectively connected to connections 24 and 28.
[0078] In this case, said bidirectional sealing means 7 comprises a second body 141 defining the second flow path 7B for a fluid between the first and second orifices 146, 147 of the second body 141 connecting the second subset of conduits of the second loop B2 to the first and / or third subset of conduits forming the first loop B1 and third loop B3. The second body 141 is arranged parallel to the interconnecting branch connecting the
[0079] Regardless of the embodiment, the bidirectional sealing means 7 comprises a secondary chamber 45 in which the pressure switch 70 is disposed. The secondary chamber 45 includes a separating plate 71 having an opening 73 through which a movable element 72 of the pressure switch 70 extends. The pressure switch includes a means 74 for returning the movable element 72 against the separating plate 71 in order to close the opening 73.
[0080] The separating plate 71 separates the pressure switch 70 into two sub-chambers connected by the opening 73. On one side, an upstream secondary chamber 45A houses the return means 74 which applies a retaining force to the moving element 72 in a closed position against the peripheral wall delimiting the opening 73. On the other side, a forward secondary chamber 45A houses another portion of the moving element 72 which is at rest against the seat defined by the peripheral wall delimiting the opening 73.
[0081] The moving element 72 comprises a rod 77 connected at its ends to upstream discs 76 and downstream discs 75 arranged respectively within the upstream secondary chambers 45A and downstream 45B.
[0082] In the rest position, the opening 73 of the pressure switch is closed so that the downstream disc 75, which is intended to move in the downstream secondary chamber 45B, is pressed against the separating plate 71, thus obstructing the opening 73 as shown in Figures 2 and 5.
[0083] When the fluid pressure in the upstream chamber 45A exceeds a threshold predefined by the calibration of the return means 74, the downstream disc 75 is moved away from the separating plate 71, which generates a flow of fluid towards the connection 24, which is fluidly connected to the expansion vessel 50. In the case of overpressure within the second loop B2, the fluid is likely to reach the expansion vessel 50 under the effect of a discharge achieved by a change of state of the pressure switch 70.
[0084] Said return means 74 may be a spring working in compression, one end of which is connected to the upstream disc 76 of the moving element 72, the other end of which is in contact with the separating plate 71.
[0085] Said return means 51 may be a compression spring, one end of which is connected to the perforated disc 30, the other end of which is continuously in contact with the ball 42. Said bidirectional closing means 7 includes a pressure switch 70 intended to create a second flow path 7B of the cooling fluid which is established from the second loop B2 to the third loop B3 comprising the expansion vessel 50. Said return means 74 of the moving element 72 against the seat of the pressure switch 70 is a spring having a higher spring rate than that of said return means 51 of the ball 42 against the seat 143 of the non-return valve 40.Under the effect of a pressure of the fluid circulating in at least one of the first and third loops B1 and B3, which is greater than the pressure of the fluid of the second loop B2, the cooling fluid is able to circulate through said bidirectional sealing means 7 then in the open state of the valve 40 such that the flow rate of the pump 41 of the second loop B2 is greater than that of the pump 42 of the first loop, thus operating a heat transfer from the elements of the first loop, such as the battery and / or the electric motor, to the heat exchanger 13.
[0086] According to the embodiment of the pressure switch 70 in Figures 2, 5 and 7, the second flow path 7B passes through a passage 48 connecting the upstream secondary chamber 45A to the first chamber 44 by passing through the wall 125. The body 41 may further include an internal tube 43 connecting the downstream secondary chamber 45B to the opening 46, the internal tube 43 partially defining the seat 143 against which the ball 42, 42B is able to come to rest. According to the embodiment of the pressure switch 70 in Figure 9, the second flow path 7B passes through the parallel conduits 116, 117 defining a bypass branch of the valve 40. The fluid circulating in the second flow path 7B moves in the opposite direction to the flow of the fluid through the first flow path 7A.Finally, the valve according to the invention makes it possible to significantly limit the exchange of heat transfer fluids exhibiting a large temperature difference between two duct loops of a thermal system. Thanks to the bidirectional device 7, the heat transfer fluid exchange between the duct loops can be reduced to the bare minimum while preventing a pressure increase in the second loop B2 when it is isolated from the first loop B1, and thus preventing damage to components of the thermal system, particularly when the volume of the liquid in the thermal system increases due to thermal expansion through fluid interaction with the single expansion vessel.
Claims
DEMANDS 1. Thermal system (1) for a vehicle comprising a first subset of conduits forming a first loop (B1) of circulation of a cooling fluid in particular through an electric motor (11) and / or a power battery (12), a second subset of conduits forming a second loop (B2) of circulation of a cooling fluid in particular through a heat exchanger (13) and / or an electric heating element (14), a third subset of conduits forming a third loop (B3) of circulation of a cooling fluid in particular through a radiator (15) and / or an expansion tank (50), and an interconnection branch comprising conduits (16, 17, 25, 26, 27, 116, 117) disposed between the first loop (B1) and at least one of the second and third loops (B2; B3), characterized in that it comprises a bidirectional shut-off means (7) disposed at the interconnection branch, and in that said bidirectional shut-off means (7) comprises a first flow path (7A) of the cooling fluid and a second flow path (7B) of the cooling fluid configured such that the flow of the cooling fluid occurs respectively according to: - a first direction (A), going from the first loop (B1) to the second loop (B2), without limited flow, to carry out a heat exchange between the first and second loops (B1, B2) and - a second direction (B) opposite to the first direction (A) going from the second loop (B2) to the third loop (B3), with a limited flow rate in order to achieve a depressurization of the second loop (B2) so that a volume of expanded fluid from the second loop (B2) is able to be discharged to the expansion vessel (50).
2. Thermal system (1) according to the preceding claim, characterized in that said bidirectional sealing means (7) comprises a main body (41) in which is disposed a non-return valve (40), a first chamber (44) defining the first flow path (7A) for a fluid between the first and second orifices (46, 47) of the body (41) connecting the second subset of conduits to the first and / or the third subset of conduits.
3. Thermal system (1) according to the preceding claim, characterized in that the non-return valve (40) comprises a ball (42), a means (51) for returning the ball (42) against a seat (143) defined by the first chamber, the ball (42) being able to move within said first chamber (44) between open (42A) and closed (42B) positions, allowing the flow of the cooling fluid through the first flow path (7A).
4. Thermal system (1) according to claim 2 or 3, characterized in that said bidirectional shut-off means (7) comprises a pressure switch (70) in fluidic contact with the first chamber (44) for said second flow path (7B) of the cooling fluid.
5. Thermal system (1) according to claim 2 or 3, characterized in that said bidirectional closing means (7) comprises a pressure switch (170) for said second flow path (7B) of the cooling fluid, the pressure switch (170) being separate from the body (41) and connecting the second subset of conduits to the first and / or third subset of conduits by parallel branches (116, 117) connected to the interconnecting branch.
6. Thermal system (1) according to the preceding claim, characterized in that said bidirectional sealing means (7) comprises a second body (141) defining the second flow path (7B) for a fluid between first and second orifices (146, 147) of the second body (141) connecting the second duct subset to the first and / or third duct subset via the pressure switch (170).
7. Thermal system (1) according to claim 5 or 6, characterized in that the bidirectional closing means (7) comprises a secondary chamber (45) in which the pressure switch (70; 170) is disposed, the secondary chamber (45) having a separating plate (71) having an opening (73) through which a movable element (72) of the pressure switch (70) extends, and a means of returning (74) the movable element (72) against the separating plate (71) in order to close the opening (73), the separating plate (71) separating the secondary chamber (45) into upstream (45A) and downstream (45B) secondary chambers.
8. Thermal system (1) according to the preceding claim, characterized in that said return means (74) of the moving element (72) is a spring having a higher spring rate than said return means (51) of the ball (42).
9. Thermal system (1) according to the preceding claim, characterized in that the movable element (72) comprises a rod (77) connected at its ends to upstream (76) and downstream (75) discs, the upstream disc (76) being disposed in the upstream secondary chamber (45A) and connected to the separation plate (71) by a return means (74) which exerts a force returning the downstream disc (75) to rest against the separation plate (71).
10. Thermal system (1) according to any one of the preceding claims, characterized in that it comprises a first set of components, among which - an electric motor (11), - a battery (12), - a thermal resistance (14), - a cooler (13) connected to an air conditioning circuit of a passenger compartment of the motor vehicle, - a radiator (15), and in that the battery (12) and the electric motor (11) are arranged in the first loop (B1), and in that the thermal resistance (14) and the cooler (13) are arranged in the second loop (B2), and in that the radiator (15) and the expansion vessel (50) are arranged in the third loop (B3).
11. Thermal system (1) according to any one of the preceding claims, characterized in that the expansion vessel (50) is unique and connected to the first loop (B1) and / or the third loop (B3) via conduits, and to the second loop (B2) via said bidirectional sealing means (7) such that an increase in pressure in conduits of the second loop (B2) causes a transfer of a quantity of fluid to the expansion vessel (50) by a change of state of said bidirectional sealing means (7).
12. Motor vehicle equipped with a thermal system (1) according to one of the preceding claims.