Thermal system for a motor vehicle

Abstract

The invention relates to a thermal system comprising: - a first subset of ducts forming a first loop for circulating a heat-transfer fluid, in which a thermal resistor is arranged; - a second subset of ducts forming a second loop for circulating a heat-transfer fluid, separate from the first loop; and - a heat exchanger arranged between a first duct portion of the first loop and a given duct portion of the second loop. The system comprises a valve and a first pump that are arranged on the first loop, and means for controlling a flow rate of the first pump in order to control the valve either to open, so as to allow a heat-transfer fluid to circulate in the first duct portion of the first loop, or to close, so as to prevent a heat-transfer fluid from circulating in the first duct portion of the first loop.

Description

[0001] TITLE: Thermal system for motor vehicle.

[0002] The invention relates to a thermal system for a motor vehicle. The invention also relates to a method for thermal management of a motor vehicle. The invention also relates to a thermal management device. The invention further relates to a motor vehicle equipped with a thermal system or a thermal management device.

[0003] To minimize the energy consumption of motor vehicles, particularly electric motor vehicles, heat transfer circuits are designed to recover the heat generated by one element of the circuit to heat another element of the circuit. More generally, a thermal circuit must allow different circulations of heat transfer fluid so as to adapt to different conditions of use of the vehicle, for example a need to heat the passenger compartment and / or a need to maintain the temperature of a traction battery within an optimal temperature range, while minimizing the energy consumption of the vehicle.

[0004] However, the implementation of such thermal circuits can be complex, and require the use of numerous controllable components, in particular numerous pumps and solenoid valves, which increases the cost and complexity of developing the thermal system.

[0005] The aim of the invention is to provide a thermal system which overcomes the above drawbacks and improves the thermal systems known from the prior art. In particular, the invention makes it possible to produce a thermal system which is reliable and efficient and which minimizes the number of controllable components. To this end, the invention relates to a thermal system for a motor vehicle comprising

[0006] - a first subset of conduits forming a first circulation loop for a heat transfer fluid, a thermal resistance being arranged in the first loop,

[0007] - a second subset of conduits forming a second loop for circulating a heat transfer fluid, the second loop being separate from the first loop, and

[0008] - a heat exchanger arranged between a first portion of conduit of the first loop and a given portion of conduit of the second loop.

[0009] In addition, the thermal system comprises a valve and a first pump arranged on the first heat transfer fluid circulation loop, as well as a means for controlling a flow rate of the first pump to control either an opening of the valve, so as to allow circulation of a heat transfer fluid in the first portion of conduit of the first loop, or a closing of the valve, so as to prevent circulation of a heat transfer fluid in the first portion of conduit of the first loop.

[0010] In one embodiment, a traction battery is arranged on the second heat transfer fluid circulation loop and / or a heater for a passenger compartment of the motor vehicle is arranged on the first loop.

[0011] In one embodiment, the first conduit portion of the first loop is branched off from a second conduit portion of the first loop, such that:

[0012] - when the valve is open, a flow rate of the heat transfer fluid generated by the first pump is distributed between a first sub-flow rate flowing in the first portion of conduit of the first loop and a second sub-flow rate flowing in the second portion of conduit of the first loop, and - when the valve is closed, a flow rate of the heat transfer fluid generated by the first pump flows substantially exclusively in the second portion of conduit of the first loop.

[0013] In one embodiment, a nozzle is provided in the second portion of conduit of the first loop so as to promote a distribution of the flow rate of the first pump between the first sub-flow rate and the second sub-flow rate when the valve is open.

[0014] In one embodiment, the valve is arranged upstream or downstream of the heat exchanger relative to a direction of circulation of a heat transfer fluid in the first loop.

[0015] In one embodiment, the system comprises a third subset of conduits forming a third loop for circulating a heat transfer fluid, in particular the third loop comprising an electric traction motor, the third loop being separate from the first loop, and the third loop comprising a valve, in particular a three-way valve, capable of alternately preventing or allowing circulation, in the second loop, of a heat transfer fluid from the third loop.

[0016] The invention further relates to a method for thermal management of a thermal system according to the invention, comprising alternating between

[0017] - a first thermal insulation step between the first loop and the second loop, comprising a control to maintain a flow rate of the first pump of the thermal system below a reference threshold, and

[0018] - a second step of heat transfer between the first loop and the second loop, comprising a command to maintain a flow rate of the first pump of the thermal system above the reference threshold. In one embodiment, the management method further comprises an alternation between:

[0019] - a third stage of implementing circulation, in the second loop, of a heat transfer fluid from the third loop, and

[0020] - a fourth step of stopping circulation, in the second loop, of a heat transfer fluid from the third loop, the third or fourth step being carried out at the same time as the first or second step.

[0021] The invention also relates to a thermal management device for a thermal system of a motor vehicle, the device comprising hardware and / or software elements implementing the method according to the invention, in particular hardware and / or software elements designed to implement the method according to the invention, and / or the device comprising means for implementing the method according to the invention.

[0022] The invention also relates to a motor vehicle with an electric or hybrid engine comprising a thermal system according to the invention or a thermal management device according to the invention.

[0023] Figure 1 schematically represents a motor vehicle equipped with a thermal system according to one embodiment of the invention.

[0024] Figure 2 illustrates a first embodiment of a thermal system according to the invention.

[0025] Figure 3 is a graph of the evolution of a fluid flow rate in a pump of a first heat transfer fluid circulation loop of a thermal system according to the invention.

[0026] Figure 4 illustrates a second embodiment of a thermal system according to the invention.

[0027] Figure 5 is a flowchart of a thermal management method according to the invention. Figure 6 illustrates a thermal insulation step between three heat transfer fluid circulation loops of the thermal system according to the invention.

[0028] Figure 7 illustrates a heat transfer step between a first and a second heat transfer fluid circulation loop and a thermal insulation step between the second and a third heat transfer fluid circulation loop of the thermal system according to the invention.

[0029] Figure 8 illustrates a thermal insulation step between the first and second heat transfer fluid circulation loops, and a heat transfer step between the second and third heat transfer fluid circulation loops of the thermal system according to the invention.

[0030] Figure 9 illustrates a heat transfer step between the first and second heat transfer fluid circulation loops, and a heat transfer step between the second and third heat transfer fluid circulation loops of the thermal system according to the invention.

[0031] An embodiment of a motor vehicle 100 according to the invention is described below with reference to Figures 1 to 9. The motor vehicle 100 is a motor vehicle of any type, in particular a passenger vehicle or a utility vehicle.

[0032] In an embodiment more specifically described in this document, the motor vehicle 100 is an electric vehicle comprising in particular

[0033] - a cabin 30 equipped with an air heater 11,

[0034] - a 12 traction battery,

[0035] - and an electric traction motor 13.

[0036] The motor vehicle 100 is equipped with a thermal management system 20 according to the invention, comprising:

[0037] - a first subset 211 of conduits forming a first loop B1 for circulating a heat transfer fluid, a thermal resistance 14 being arranged in the first loop B1, - a second subset 212 of conduits forming a second loop B2 for circulating a heat transfer fluid, the second loop B2 being separate from the first loop B1, and

[0038] - a heat exchanger 15 arranged between a first portion of conduit 2111 of the first loop B1 and a given portion 2121 of conduit of the second loop B2.

[0039] A first embodiment of a system 20 is described below with reference to FIG. 2.

[0040] The heat exchanger 15 may also be called a water-water exchanger 15. In the remainder of the document, the term “water” designates a heat transfer fluid, for example glycolated water or a dielectric fluid.

[0041] Loop B1 implements a passenger compartment heating circuit 30. In the embodiment illustrated in Figure 2, in addition to the thermal resistance 14, the heating circuit comprises:

[0042] - a jar 271,

[0043] - an electric water pump 231,

[0044] - a temperature sensor 251,

[0045] - an air heater 11 which implements a transfer, to the passenger compartment 30, of calories from a heat transfer fluid circulating in the loop B1,

[0046] - a valve 221 also called a “discharge valve”, and

[0047] - the heat exchanger 15.

[0048] Advantageously, the valve 221 is a so-called “discharge” valve, which is calibrated to open automatically when the pressure of a heat transfer fluid circulating in the loop B1 exceeds a predetermined threshold.

[0049] Advantageously, the thermal resistance 14 is a high voltage electrical resistance. Different embodiments of a valve 221 are conceivable. For example, the valve 221 may comprise

[0050] - a valve body,

[0051] - a bore provided inside the valve body, the bore defining a passage for a fluid, in a first direction, between a first orifice of the valve and a second orifice of the valve, and

[0052] - a shutter capable of moving in the bore between a first position and a second position, the first position preventing the fluid from flowing, and the second position allowing the fluid to flow in the first direction.

[0053] The first direction corresponds to the direction of flow of the heat transfer fluid controlled by the pump 231. In addition, the first orifice of the valve 221 is located on the side of the pump 231 relative to the shutter.

[0054] In one embodiment, the shutter may be held in the first position by a spring whose compressive strength is calibrated so that,

[0055] - when the speed of the pump 231 is lower than a first speed threshold S_ref then the shutter of the valve 221 is in the first position, therefore the valve 221 is closed, and

[0056] - when the flow rate of heat transfer fluid controlled by the pump 231 is greater than the speed threshold S_ref, then the shutter of the valve 221 is in the second position, therefore the valve 221 is open.

[0057] Figure 3 represents a graph G1 of the time evolution of a flow rate V_231 of the heat transfer fluid of the first loop B1, the flow rate being controlled by the first pump 231. Between an instant T0 and an instant T1, the speed V_231 is maintained at a value V1 strictly lower than the threshold S_ref. The valve 221 is then closed, and the first loop B1, in particular the thermal resistance 14, is used only for heating the passenger compartment. From the instant T1, the speed V_231 is maintained at a value V2 strictly higher than the threshold S_ref. The valve 221 is then open, and the first loop B1, in particular the thermal resistance 14, is used to maintain the battery 12 in an optimal temperature range, and if necessary, to heat the passenger compartment by circulating air through the air heater 11.

[0058] In addition, the thermal management system 20 comprises a means 241 for controlling a flow rate of the pump 231, capable of implementing:

[0059] - either an opening of the valve 221, illustrated by figures 7 and 9, so as to allow circulation of a heat transfer fluid in the first portion 2111 of conduit of the first loop B1,

[0060] - either a closure of the valve 221, illustrated by figures 6 and 8, so as to prevent circulation of a heat transfer fluid in the first portion 2111 of conduit of the first loop B1.

[0061] The second loop B2 implements a thermal management circuit of the traction battery 12, which includes an electric water pump 232, and a temperature sensor 252.

[0062] In addition, the given portion 2121 of conduit of the second loop B2 passing through the heat exchanger 15 allows a heat exchange between the first loop B1 and the second loop B2 when the valve 221 of the first loop B1 is open.

[0063] Thus, the thermal system 20 according to the invention makes it possible to control the implementation or stopping of a thermal transfer between the first loop B1 and the second loop B2 by modifying the flow rate of the pump 231 arranged on the first loop B1.

[0064] In the remainder of the document, the terms "circulation loop" or "loop" are used to designate a closed circuit of conduits allowing circulation of heat transfer fluid in said circuit. In the remainder of the document, the first fluid circulation loop B1 is said to be "disjointed" from the second fluid circulation loop B2. This means that the heat transfer fluids circulating respectively in the first loop B1 and the second loop B2 do not mix. The expression "fluidically isolated" is also used to describe two disjointed fluid circulation loops. In other words, a fluid circulating in the first loop B1 does not circulate in the second loop B2 and vice versa. The proximity of the portions of conduits 2111 and 2121 circulating in the heat exchanger 15 allows heat transfer between the loops B1 and B2, without the heat transfer fluids of these loops mixing.

[0065] As will be described later in this document, the thermal system may advantageously comprise a third sub-assembly 213 of conduits forming a third loop B3 for circulating a heat transfer fluid, the electric traction motor 13 being arranged in the third loop B3.

[0066] As a note, each of the loops B2, B3 includes a pump 232, 233 for adjusting the flow rate of heat transfer fluid in the loop B2, B3.

[0067] In addition, the thermal system 20 advantageously comprises a fourth subset of conduits 214 implementing a fourth air conditioning loop B4, in particular implementing a circulation of a refrigerant, for example a circulation of a fluid of the R134a, R1234yf, R744, or R290 type. The air conditioning loop B4 comprises in particular an expansion valve 25, an evaporator 26, a compressor 27 and a condenser 28. The fourth loop B4 is fluidically isolated from the three other loops B1, B2, B3. A heat transfer can take place between the fourth loop B4 and each of the three other loops B1, B2, B3. The fourth loop B4 makes it possible in particular to air condition the passenger compartment 30 of the motor vehicle 100 thanks to the evaporator 26 arranged in the housing 261 of a heating, air conditioning and ventilation system.The fourth loop B4 also makes it possible to act on the temperature of the heat transfer fluid circulating in the second loop B2 via a cooler 29.

[0068] Advantageously, the traction battery 12 is arranged on the second loop B2 for circulating heat transfer fluid; in addition, the thermal resistor 14 is arranged on the first loop B1 dedicated to heating the passenger compartment 30 of the motor vehicle 100. Thus, the thermal system 20 according to the invention makes it possible to activate and deactivate, by means of the pump 231, a thermal transfer, in particular a heat transfer, between, on the one hand, the thermal resistor 14 arranged on the first loop B1 and, on the other hand, the battery 12 arranged on the second loop B2.

[0069] In the embodiment described, the first portion 2111 of conduit of the first loop B1 is branched off from a second portion 2112 of conduit of the first loop B1.

[0070] Thus, when the valve 221 is open, a flow rate of heat transfer fluid generated by the pump 231 is distributed between a first sub-flow rate SD1 flowing in the first portion 2111 of conduit of the first loop B1 and a second sub-flow rate SD2 flowing in the second portion 2112 of conduit of the first loop B1.

[0071] Furthermore, when the valve 221 is closed, a flow SD3 of heat transfer fluid generated by the pump 231 flows substantially exclusively in the second portion 2112 of conduit of the first loop.

[0072] In other words, the first loop B1 comprises two points P1, P2 connected to each other by the first portion 2111 of conduit and the second portion 2112 of conduit which are connected in parallel. Thus, depending on the pressure of the heat transfer fluid generated by the pump 231, the circulation of fluid between the points P1 and P2 can comprise,

[0073] - either a circulation of fluid taking place substantially only in the second portion of conduit 2112,

[0074] - either a circulation of fluid taking place simultaneously in the first portion 2111 of conduit and the second portion 2112 of conduit.

[0075] In a second embodiment of the thermal system illustrated by FIG. 4, a nozzle 60 is made in the second portion 2112 of conduit of the first loop B1 so as to promote a distribution of the flow rate of the pump between the first sub-flow rate SD1 and the second sub-flow rate SD2 when the valve 221 is open.

[0076] The nozzle 60 consists of a reduction of a section of the second portion 2112 of conduit. The reduction can be achieved by inserting and fixing a part in the second portion of conduit, the part thus mechanically reducing the section of the second portion 2112 of conduit.

[0077] The nozzle 60 thus slows the passage of the heat transfer fluid in the second portion 2112 of the conduit.

[0078] The valve 221 may be arranged either upstream or downstream of the heat exchanger 15 relative to a direction of circulation of a heat transfer fluid in the first loop B1. As a remark, the placement of the valve 221 upstream of the heat exchanger 15 seems to be preferable, because a placement of the valve 221 downstream of the heat exchanger 15 can generate pressure variations in the first portion 2111 of conduit of the loop B1.

[0079] The third loop B3 is separate from the first loop B1, and the third loop comprises a valve 50, in particular a three-way solenoid valve 50, capable of alternately preventing or allowing circulation, in the second loop B2, of a heat transfer fluid from the third loop B3. For this purpose, an outlet 501 of the valve 50 is connected to the second loop B2, at a point A located upstream of the pump 232 relative to a direction of circulation of the heat transfer fluid of the second loop B2. The circulation, in the second loop B2, of a heat transfer fluid from the third loop B3 has the objective of using the heat released by the electric traction motor 13 to heat the battery 12.

[0080] In the remainder of the document, the term “motor 13” is used to designate the electric motor itself, as well as various components associated with the motor, and located close to the motor, such as for example current converters and a charger. In other words, the term “motor 13” encompasses a set of components dedicated to the operation of the motor 13, in particular the electric traction chain comprising one or more electric motors and inverters and / or one or more converters and / or one or more chargers.

[0081] The thermal system 20 may advantageously comprise a controller 40 which determines which circulation of heat transfer fluid must be implemented. In particular, the controller 40 may determine whether it is advantageous to implement a heat transfer between the first and second fluid circulation loops, and / or whether it is advantageous to implement a heat transfer between the third and second fluid circulation loops.

[0082] The controller 40 can, for example, manage the transition conditions from one circulation to another, for example as a function of the temperatures measured by temperature sensors 251, 252, 253 of the different loops B1, B2, B3, B4, and / or as a function of a temperature of air outside the vehicle and / or as a function of a passenger compartment temperature setpoint.

[0083] The invention further relates to a thermal management device 70 comprising a thermal system 20 according to the invention.

[0084] In an advantageous embodiment, the thermal management device 70 comprises the means for implementing a method for managing a thermal system 20 according to the invention. In particular, the thermal management device 70 comprises a processing unit 80 comprising a microprocessor 81, a memory 82 and communication interfaces 83.

[0085] The thermal management device 70 and particularly the microprocessor 81, mainly comprises the following modules which cooperate with each other:

[0086] - a thermal insulation module 811 between the first loop B1 and the second loop B2, this module being able to cooperate with the controller 40, the temperature sensors 251, 252 of the first and second circulation loops B1, B2 and the pump 231 of the first circulation loop B1,

[0087] - a module 812 for heat transfer between the first loop B1 and the second loop B2, this module being able to cooperate with the controller 40, the temperature sensors 251, 252 of the first and second circulation loops B1, B2 and the pump 231 of the first circulation loop B1,

[0088] - a module 813 for implementing a circulation, in the second loop B2, of a heat transfer fluid from the third loop B3, this module being able to cooperate with the controller 40, the solenoid valve 50, the temperature sensors 252, 253 of the second and third circulation loops B2, B3 and the pumps 232, 233 of the second and third loops B2, B3, - a module 814 for stopping a circulation, in the second loop B2, of a heat transfer fluid from the third loop B3, this module being able to cooperate with the controller 40, the solenoid valve 50, the temperature sensors 252, 253 of the second and third circulation loops B2, B3 and the pumps 232, 233 of the second and third loops B2, B3.

[0089] The motor vehicle 100, in particular the thermal management device 70, preferably comprises all the hardware and / or software elements configured so as to implement the method defined in the subject of the invention or the method described below.

[0090] Referring to Figure 5, a thermal management method is described comprising

[0091] - a first alternation between, on the one hand, a first step E1 of thermal insulation between the first loop B1 and the second loop B2, and, on the other hand, a second step E2 of thermal transfer between the first loop B1 and the second loop B2, and

[0092] - a second alternation between, on the one hand, a third step E3 of implementing a circulation in the second loop B2 of a heat transfer fluid from the third loop B3, and, on the other hand, a fourth step E4 of stopping a circulation in the second loop B2 of a heat transfer fluid from the third loop B3, the first and second alternations being executed in parallel with each other.

[0093] In other words, in the embodiment presented, the thermal management method according to the invention simultaneously implements:

[0094] - a step taken from the first or second step, E1, E2, and

[0095] - a step taken from the third or fourth step, E3, E4.

[0096] The first step E1 is illustrated by Figures 6 and 8. In the first step E1, the speed of the pump 231 of the first loop B1 is controlled so as to implement a first threshold S1 of fluid flow rate strictly lower than the reference speed threshold S_ref. The valve 221 is then closed and the resistor 14 of the first loop B1 is exclusively used to heat the passenger compartment of the vehicle. Thus, substantially no heat transfer fluid circulates in the first circuit portion 2111 of the first loop B1. The exchanger 15 is therefore not crossed by a heat transfer fluid from the first loop B1, and no heat exchange between the first loop B1 and the second loop B2 is carried out.

[0097] The second step E2 is illustrated by Figures 7 and 9. In the second step E2, the speed of the pump 231 is controlled so as to remain above a second speed threshold S2. As illustrated by Figure 6, the valve 221 is then open. Thus, a flow rate of heat transfer fluid generated by the pump 231 is distributed between a first sub-flow rate SD1 flowing in the first portion 2111 of conduit of the first loop B1 and a second sub-flow rate SD2 flowing in the second portion 2112 of conduit of the first loop B1. The exchanger 15 is therefore crossed by a heat transfer fluid from the first loop B1, and a heat exchange takes place between the first loop B1 and the second loop B2.

[0098] The third step E3 is illustrated by Figures 8 and 9. The valve 50 is then controlled to create a circulation of a heat transfer fluid from the third loop B3 to the second loop B2. The heat transfer fluid flows through an outlet 501 of the three-way valve 50, the outlet 501 communicating with an inlet point A of a conduit of the second loop B2. Thus, the heat transfer fluid from the third loop B3 enters the loop B2 at point A located upstream of the pump 232 of the second loop B2. The fourth step E4 is illustrated by Figures 6 and 7. The valve 50 is then controlled to prevent a circulation of a heat transfer fluid from the third loop B3 to the second loop B2. The outlet 501 is therefore closed, preventing the heat transfer fluid from flowing towards the inlet point A of a conduit of the second loop B2. Thus, the heat transfer fluid from the third loop B3 is isolated from the second loop B2.

[0099] Finally, a thermal system according to the invention makes it possible to optimize the thermal management of the motor vehicle 100 according to the conditions of use of the vehicle, while minimizing the number of controllable components.

[0100] The technical solution implemented in the invention consists of equipping the passenger compartment thermal management circuit with a relief valve and arranging a heat exchanger between the passenger compartment thermal management circuit and the traction battery thermal management circuit. The valve is located upstream, or possibly downstream, of the heat exchanger, the opening of the valve being controllable by the pump equipping the passenger compartment thermal management circuit.

[0101] Advantageously, the relief valve is a purely mechanical component and can be easily pre-calibrated to open at a desired calibration threshold.

[0102] The pump equipping the passenger compartment thermal management circuit makes it possible to control the implementation or stopping of a thermal exchange between the passenger compartment thermal management circuit and the traction battery thermal management circuit.

[0103] In fact, when the pump is commanded to generate a pressure lower than the valve calibration threshold, the valve prevents the circulation, in the heat exchanger, of the heat transfer fluid from the passenger compartment thermal management circuit. The calories supplied by the high-voltage electrical resistance are then supplied exclusively to the passenger compartment heating circuit air heater.

[0104] Alternatively, when the pump is commanded to generate a pressure greater than the valve calibration threshold, the valve allows the circulation, in the heat exchanger, of the heat transfer fluid from the passenger compartment thermal management circuit. All the calories supplied by the high-voltage electrical resistor are then transmitted to the battery thermal management circuit in the absence of a need for heating the passenger compartment. Otherwise, the calories resulting from the operation of the electrical resistor are distributed between the passenger compartment and battery thermal management circuits.

[0105] The implementation of the invention thus lies in the use of a valve, which is a simple and purely mechanical component to apply. In addition, the regulation logic of an electric water pump is already present in existing systems and does not require the development of new functionalities.

Claims

CLAIMS 1. Thermal system (20) of a motor vehicle (100), the thermal system (20) comprising: - a first subset (211) of conduits forming a first loop (B1) for circulating a heat transfer fluid, a thermal resistance (14) being arranged in the first loop (B1), - a second subset (212) of conduits forming a second loop (B2) for circulating a heat transfer fluid, the second loop (B2) being separate from the first loop (B1), and - a heat exchanger (15) arranged between a first portion (2111) of conduit of the first loop (B1) and a given portion (2121) of conduit of the second loop, characterized in that it comprises a valve (221) and a first pump (231) arranged on the first loop (B1) for circulating heat transfer fluid, as well as a means (241) for controlling a flow rate of the first pump (231) to control either an opening of the valve (221), so as to allow circulation of a heat transfer fluid in the first portion (2111) of conduit of the first loop (B1), or a closing of the valve (221), so as to prevent circulation of a heat transfer fluid in the first portion (2111) of conduit of the first loop (B1).

2. Thermal system (20) according to the preceding claim, characterized in that a traction battery (12) is arranged on the second heat transfer fluid circulation loop (B2).

3. Thermal system (20) according to one of the preceding claims, characterized in that a heater (11) of a passenger compartment (30) of the motor vehicle (100) is arranged on the first loop (B1).

4. Thermal system (20) according to one of the preceding claims, characterized in that the first portion (2111) of conduit of the first loop (B1) is a branch of a second portion (2112) of conduit of the first loop (B1), so that: - when the valve (221) is open, a flow rate of the heat transfer fluid generated by the first pump (231) is distributed between a first sub-flow rate (SD1) flowing in the first portion (2111) of the conduit of the first loop (B1) and a second sub-flow rate (SD2) flowing in the second portion (2112) of the conduit of the first loop (B1), - when the valve (221) is closed, a flow rate (SD3) of the heat transfer fluid generated by the first pump (231) flows substantially exclusively in the second portion (2112) of conduit of the first loop (B1).

5. Thermal system (20) according to the preceding claim, characterized in that a nozzle (60) is produced in the second portion (2112) of conduit of the first loop (B1) so as to promote a distribution of the flow rate of the first pump (231) between the first sub-flow rate (SD1) and the second sub-flow rate (SD2) when the valve (221) is open.

6. Thermal system (20) according to one of the preceding claims, characterized in that the valve (221) is arranged upstream or downstream of the heat exchanger (15) relative to a direction of circulation of a heat transfer fluid in the first loop (B1).

7. Thermal system (20) according to one of the preceding claims, characterized in that the system comprises a third sub-assembly (213) of conduits forming a third loop (B3) for circulating a heat transfer fluid, in particular the third loop comprising (B3) an electric traction motor (13), in that the third loop (B3) is separate from the first loop (B1), and in that the third loop (B3) comprises a valve (50), in particular a three-way valve (50), capable of alternately preventing or allowing circulation, in the second loop (B2), of a heat transfer fluid from the third loop (B3).

8. Method for thermal management of a thermal system (20) according to one of claims 1 to 7, characterized in that it comprises an alternation between - a first step (E1) of thermal insulation between the first loop and the second loop, comprising a command to maintain a flow rate of the first pump (231) of the thermal system (20) below a reference threshold (S_ref), and - a second step (E2) of heat transfer between the first loop and the second loop, comprising a command to maintain a flow rate of the first pump (231) of the thermal system (20) above the reference threshold (S_ref).

9. Management method according to the preceding claim of a thermal system (20) according to claim 7, characterized in that it further comprises an alternation between: - a third step (E3) of implementing circulation, in the second loop (B2), of a heat transfer fluid from the third loop (B3), and - a fourth step (E4) of stopping circulation, in the second loop (B2), of a heat transfer fluid from the third loop (B3), the third or fourth step (E3, E4) being carried out at the same time as the first or second step (E1, E2).

10. Device (70) for thermal management of a thermal system (20) of a motor vehicle (100), the device comprising elements (11, 12, 13, 14, 15, 20, 30, 40, 50, 60, 80, 81, 82, 83, 211, 212, 213, 214, 221, 231, 232, 233, 241, 251, 252, 253, 261, 271, 501, 811, 812, 813, 814, 2111, 2112, 2121) hardware and / or software implementing the method according to one of claims 8 or 9, in particular hardware elements (11, 12, 13, 14, 15, 20, 30, 40, 50, 60, 80, 81, 82, 83, 211, 212, 213, 214, 221, 231, 232, 233, 241, 251, 252, 253, 261, 271, 501, 2111, 2112, 2121) and / or software designed to implement the method according to one of claims 8 or 9.

11. Motor vehicle (100) with electric or hybrid motorization comprising a thermal system (20) according to one of claims 1 to 7 or a thermal management device according to claim 10.

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