Thermal system for a motor vehicle

Abstract

Disclosed is a thermal system (70) for a motor vehicle (100), the vehicle being equipped with an electric motor (20) and an internal combustion engine (10), characterized in that the thermal system comprises a fuel cell (30) for energizing the electric motor (20), a system (60) for aftertreatment of the exhaust gases of the combustion engine (10), and a circuit (71) comprising a first set of ducts (101), the first set of ducts (101) being arranged to allow a first circulation of a heat transfer fluid from the fuel cell (30) to the aftertreatment system (60).

Description

[0001] 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 further relates to a motor vehicle equipped with a thermal system.

[0003] Engines that use hydrogen as a power source are mainly of two types. The first type uses hydrogen in a fuel cell that powers an electric motor. The second type uses hydrogen as fuel in an internal combustion engine. Both the first and second types of engines have advantages.

[0004] The advantages of a motor of the first type include in particular very high efficiency when using the vehicle at low power, and the absence of regulated pollutant emissions when using an electric motor.

[0005] The advantages of the second type of engine are the ability to generate high power output with high efficiency. On the other hand, the internal combustion engine produces regulated pollutants in small quantities.

[0006] Patent US6899062B2 discloses a system combining both types of engines and implementing a cooling circuit shared between the first and second types of engine. However, this thermal management solution is not optimal.

[0007] The aim of the invention is to provide a thermal system that overcomes the above drawbacks and improves the known systems of the prior art. In particular, the invention makes it possible to produce a thermal system that is reliable and efficient, which makes it possible to simplify the thermal management of both types of engines while optimizing the operating conditions of each type of engine.

[0008] To this end, the invention relates to a thermal system for a motor vehicle, the vehicle being equipped with an electric motor and an internal combustion engine, comprising a fuel cell capable of powering the electric motor, a system for post-treatment of the exhaust gases from the combustion engine and a circuit comprising a first set of conduits, the first set of conduits being arranged to allow a first circulation of a heat transfer fluid from the fuel cell to the post-treatment system.

[0009] In one embodiment, the thermal system comprises a first heat exchanger comprising a fluid entry point into the first heat exchanger and a fluid exit point from the first heat exchanger.

[0010] In addition, the circuit, the first set of conduits of which connects a first point located near the fuel cell and a second point located near the post-treatment system, also comprises:

[0011] - a second set of conduits connecting the outlet point and the first point, the second set of conduits being arranged to allow a second circulation of heat transfer fluid for cooling the stack and / or,

[0012] - a third set of conduits connecting the outlet point and a third point, located near the combustion engine, the third set of conduits being arranged to allow a third circulation of heat transfer fluid for cooling the combustion engine and / or,

[0013] - a fourth set of conduits connecting the outlet point and a fourth point, located near the electric motor, the fourth set of conduits being arranged to allow a fourth circulation of heat transfer fluid for cooling the electric motor.

[0014] In one embodiment, the circuit further comprises:

[0015] - a fifth set of conduits connecting the first point and the third point, the fifth set of conduits being arranged to allow a fifth circulation of heat transfer fluid from the cell to the combustion engine, and / or

[0016] - a sixth set of conduits connecting the third point and the first point, the sixth set of conduits being arranged to allow a sixth circulation of heat transfer fluid from the combustion engine to the cell, and / or

[0017] - a seventh set of conduits connecting the second point and the first point, the seventh set of conduits being arranged to allow a seventh circulation of heat transfer fluid from the post-treatment system to the stack.

[0018] In one embodiment, the fuel used by the cell is dihydrogen, and / or the cell is of the proton exchange membrane type, and / or the cell is of the high temperature proton exchange membrane type.

[0019] In one embodiment, the heat transfer fluid is a synthetic heat transfer fluid in liquid phase and / or the heat transfer fluid is effective over a temperature range greater than or equal to 100 degrees, or even greater than or equal to 200 degrees, in particular over a temperature range of -40°C to 200°C, or even over a temperature range of -85°C to 260°C.

[0020] In one embodiment, the aftertreatment system comprises an exhaust gas flow duct portion containing a catalyst and the circuit comprises a second heat exchanger for implementing heat transfer between a heat transfer fluid circulating in the second heat exchanger and the duct portion. In addition, the duct portion and a heat exchange surface of the second heat exchanger are cylindrical in shape, and the heat exchange surface surrounds the duct portion.

[0021] Additionally or alternatively, the heat transfer fluid flows in a direction opposite to a flow direction of the exhaust gases in the duct portion.

[0022] The invention further relates to a method for thermal management of a motor vehicle equipped with a fuel cell, an electric motor, a combustion engine, a system for post-treatment of the exhaust gases of the combustion engine, and a thermal system according to the invention comprising an iteration of the following steps:

[0023] - a first stage of thermal management of an operating phase of the battery and the electric motor, then

[0024] - a second stage of anticipation of an imminent start of the combustion engine and the post-treatment system, then

[0025] - a third stage of thermal management of an operating phase of the combustion engine and the post-treatment system, then

[0026] - a fourth step of anticipation of an upcoming start-up of the cell, and the second step comprises an implementation of the first circulation of heat transfer fluid and, optionally, an implementation of the fifth circulation of heat transfer fluid.

[0027] In one embodiment of the thermal management method:

[0028] - the first stage and the second stage comprise an implementation of the second circulation and the fourth circulation of heat transfer fluid, and / or

[0029] - the third stage and the fourth stage comprise an implementation of the third circulation of heat transfer fluid, and / or - the fourth stage comprises an implementation of the sixth circulation and / or the seventh circulation of heat transfer fluid.

[0030] The invention further relates to a thermal management system according to the invention, the system comprising hardware and / or software elements implementing the method according to the invention, in particular hardware and / or software elements designed to implement a method according to the invention.

[0031] The invention also relates to a motor vehicle equipped with a thermal management system according to the invention.

[0032] These objects, characteristics and advantages of the present invention will be explained in detail in the following description of a particular embodiment made without limitation in relation to the attached figures among which:

[0033] Figure 1 schematically represents a motor vehicle equipped with a thermal system according to one embodiment of the invention.

[0034] Figure 2 shows a vehicle equipped with an electric motor powered by a fuel cell and a hydrogen thermal engine.

[0035] Figure 3 illustrates a first embodiment of a thermal system according to the invention.

[0036] Figure 4 is a perspective view of one embodiment of a heat exchanger for an aftertreatment system.

[0037] Figure 5 shows a post-treatment system equipped with a heat exchanger for a post-treatment system.

[0038] Figure 6 illustrates a second embodiment of a thermal circuit according to the invention.

[0039] Figure 7 illustrates a third embodiment of a thermal circuit according to the invention. An embodiment of a motor vehicle 100 according to the invention is described below with reference to Figures 1 and 2. The motor vehicle 100 is a motor vehicle of any type, in particular a passenger vehicle or a utility vehicle. The motor vehicle 100 is a hydrogen vehicle, that is to say a vehicle using energy from the oxidation of hydrogen to move.

[0040] In an embodiment more specifically described in this document, the motor vehicle 100 is a hybrid vehicle comprising both a first internal combustion engine 10 running on hydrogen and a second electric motor 20 powered from electrical energy from a fuel cell 30 powered by hydrogen. In the remainder of the document, the first engine 10 is called combustion engine 10 or heat engine 10.

[0041] In the remainder of the document, a thermal system 70 is defined which supports the thermal management of the first and second engines of the motor vehicle 100. The thermal system 70 comprises the first and second engines 10, 20 and the battery 30.

[0042] For its operation, the fuel cell 30 must be associated with a high-voltage battery 14, and with two converters 15, 16. The battery 14 supplies energy to the electric motor in specific situations, for example in a starting phase of the electric motor, when the battery has not yet reached its optimal operating temperature. The battery 14 also makes it possible to provide high power very quickly in a transient driving phase.

[0043] According to one embodiment, the fuel cell 30 comprises three elements: an oxidizing anode that emits electrons, a reducing cathode that collects electrons and an electrolyte that separates them. A reservoir supplies the two electrodes with fuel, the anode receiving hydrogen and the cathode oxygen. The anode oxidizes the fuel, then releases electrons that the electrolyte will force to pass through an external circuit. This generates a direct electric current. This process is called "oxidation". For its part, the oxygen present in the cathode will react upon contact with the electrons released by the reaction described above. This is a "reduction" that produces heat and water.

[0044] In order to enable the first and second engines to operate, the thermal system 70 further includes:

[0045] - a hydrogen storage system 40 comprising an interface for its filling and making it possible to supply hydrogen to the combustion engine 10 and the fuel cell 30,

[0046] - a transmission shaft 50 connected to the first and second motors 10, 20 and transmitting a rotational movement to the wheels of the motor vehicle 100,

[0047] - a post-treatment system 60 for the exhaust gases of the first engine 10.

[0048] The post-treatment system 60 has the role of treating the nitrogen oxides generated by the heat engine 10 during the combustion of hydrogen. The post-treatment system makes it possible to generate nitrogen molecules from the nitrogen oxides.

[0049] The thermal system 70, comprising a thermal circuit 71 according to the invention, the thermal circuit 71 making it possible to manage

[0050] - on the one hand the cooling of the fuel cell 30 and the first engine 10, and

[0051] - on the other hand the heating of the post-treatment system 60. Furthermore, during a period of time preceding a transition between a driving phase using the heat engine and a driving phase using the electric motor, the thermal circuit 71 can make it possible to use the heat generated by the heat engine and / or the post-combustion system to heat the cell 30 to bring it to a temperature close to its operating temperature, for example a temperature close to 100 degrees.

[0052] In addition, during a period of time preceding a driving phase using the electric motor and a driving phase using the thermal engine, the thermal circuit 71 can make it possible to heat the post-treatment system and / or the thermal engine to bring it to a temperature close to its operating temperature, for example a temperature close to 100 degrees.

[0053] In the different embodiments represented by figures 3 to 5, the thermal circuit 71 comprises,

[0054] - a first set of conduits 101 connecting a first point A located near the fuel cell and a second point B located near the post-treatment system 60,

[0055] - a heat exchanger 72 having an inlet 721 and an outlet 722 for the heat transfer fluid,

[0056] - a first pump 73 placed downstream of the outlet 722, generating a circulation of a cooled heat transfer fluid towards a three-way valve 731, making it possible to direct the heat transfer fluid towards the battery and / or the heat engine and / or the electric motor for their cooling,

[0057] - a second pump 74 placed upstream of the inlet 721, generating a circulation of a heat transfer fluid heated by a passage near the heat engine and / or near the post-treatment system 60 and / or near the cell in operation. The implementation, by the thermal circuit 71, of a cooling or a heating of a given element of the thermal system 40 (the given element being able to be, for example, the fuel cell or the post-treatment system 60) requires that a portion of the thermal circuit 71 be arranged at a short distance from said given element. In other words, a portion of the thermal circuit 71 must circulate at a sufficiently short distance from said given element to allow a heat transfer between the portion of the thermal circuit and said given element.

[0058] In the remainder of the document, the expression "point X is close to element Y" must be interpreted as meaning "point X is at a sufficiently short distance from element Y to allow heat transfer between a heat transfer fluid circulating at point X and element Y".

[0059] For example, the expression “a first point A located near the fuel cell” must be interpreted as “a first point A located at a sufficiently short distance from the fuel cell to allow heat transfer between a heat transfer fluid circulating at point A and the fuel cell.”

[0060] The expression "in proximity to" can also be used to locate a portion of the thermal circuit 71 at a sufficiently small distance from a given element to allow thermal transfer between said portion of the thermal circuit 71 and the given element.

[0061] In the remainder of the document, the expressions “point A”, “point B”, “point C”, or “point D” are used to designate a portion of the circuit 71 located near an element to be cooled or heated. For example, the term “point A” designates a portion of the circuit 71 located near the stack 30. Depending on the context in which it is used, the term “point A” may designate either an area upstream of the stack 30 relative to the direction of circulation of the heat transfer fluid, or an area downstream of the stack 30 relative to the direction of circulation of the heat transfer fluid.

[0062] The circuit 71 comprises a first cut-off valve 732 arranged on a portion of the cold heat transfer fluid inlet circuit near the post-treatment system 60. The first cut-off valve 732 offers the possibility of cooling the heat engine 10 without cooling the post-treatment system 60.

[0063] In an embodiment presented later with reference to FIG. 7, the circuit 71 further comprises a second cut-off valve 733

[0064] Thus, the thermal circuit 71 comprises a first set of conduits 101 arranged to allow a first circulation of a heat transfer fluid between a first point A located near the fuel cell and a second point B located near the post-treatment system 60, so as to implement a transfer of heat from the fuel cell 30 to the post-treatment system 60.

[0065] In other words, the first set of conduits 101 makes it possible to heat the post-treatment system 60 from the heat generated by the battery 30. The first circulation is particularly advantageous in a time interval preceding a transition between an operating phase of the electric motor 20, and an operating phase of the thermal engine 10, requiring the start-up of the post-treatment system 60. Thus, at the time of its start-up, the post-treatment system 60 will have been preheated by the implementation of the first circulation.

[0066] The feasibility and effectiveness of such preheating of the post-treatment system 60 requires a match between the temperature of the heat transfer fluid and an optimal temperature for the operation of the post-treatment system 60.

[0067] However, the temperature of the heat transfer fluid depends in particular on the operating temperature of the cell 30. In particular, a proton exchange membrane type cell can heat the heat transfer fluid to a temperature of approximately 100 degrees, which allows the post-treatment system 60 to reach this temperature before its start-up, thanks to the implementation of the first circulation 101.

[0068] The temperature of 100 degrees thus reached by the aftertreatment system 60 is below the minimum temperature from which it can operate, which is generally around 200 degrees. This is the case in particular for aftertreatment systems using a catalysis technology called "selective catalytic reduction". This technology, which is the most suitable for neutralizing the nitrogen oxide molecules emitted by the combustion engine 10, is effective as soon as the catalyst reaches a temperature above 200 or 225 degrees.

[0069] Preheating the aftertreatment system makes it possible to reduce the time taken for the aftertreatment system 60 to heat up to the minimum operating temperature of the catalyst, and therefore to reduce the quantity of nitrogen oxide molecules emitted between a time when the combustion engine 10 is started and a time when the catalyst reaches an optimum operating temperature. In the case of an electrically assisted aftertreatment system, for example, preheating the aftertreatment system also makes it possible to reduce the electrical energy required to bring the aftertreatment system 60 to its minimum operating temperature. Alternatively, a second type of proton exchange membrane cell known as a “high temperature” cell can heat the heat transfer fluid to a temperature of approximately 200 degrees.In this case, preheating the aftertreatment system 60 is particularly advantageous, since it allows the catalyst to reach its optimum operating temperature before the instant of starting the combustion engine 10.

[0070] The choice of the heat transfer fluid must be made according to an operating temperature range of the various components intended to be cooled or heated by the thermal circuit 71. Such a choice influences the efficiency of a temperature transfer between a heat source (the stack 30, in the case of the first circulation) and an element to be heated (the post-treatment system 60, in the case of the first circulation). Some fluids have very wide operating ranges. In particular, certain heat transfer fluids in synthetic liquid phase have excellent heat transfer properties over a wide temperature range. They are thus very advantageous for applications requiring efficient cooling and heating ranges and offer excellent heat transfer rates, even at -45°C, their recommended operating temperature range being between -85°C and 260°C.

[0071] Figure 3 shows a first embodiment of a circuit 71, in which the battery 30, the combustion engine 10 and the post-treatment system 60 are connected to the circuit 71, while the electric motor 20 is not connected to the circuit 71.

[0072] Figure 6 shows a second embodiment of a circuit 71, in which the battery 30, the electric motor 20, the combustion engine 10 and the aftertreatment system 60 are connected to the circuit 71.

[0073] Figure 7 represents a third embodiment of a circuit 71, which is a variant of the first embodiment, in which a purge system 734 of the heat transfer fluid and a second cut-off valve 733 have been added, in the part of the cooling circuit relating to the post-treatment system 60. The purge system 734 makes it possible to drain the heat transfer liquid in contact with the post-treatment system when the latter is at a very high temperature, for example during phases where it has reached its operating temperature.

[0074] In an advantageous embodiment of the thermal system 70, the circuit 71 further comprises a second heat exchanger 75 intended to promote heat transfer between the heat transfer fluid and a portion of the conduit of the post-treatment system containing a catalyst. For this purpose, the second heat exchanger has a heat exchange surface 754 with the first portion of the conduit.

[0075] Figures 4 and 5 illustrate an embodiment of a second heat exchanger 75. Figure 5 represents an exhaust system 90 comprising a post-treatment system 60 arranged upstream of an exhaust duct 80, relative to a direction of circulation 759 of the exhaust gases. The second heat exchanger 75 is arranged near the duct portion of the post-treatment system containing a catalyst.

[0076] In the embodiment presented, the duct portion and the heat exchange surface 754 of the second exchanger 75 are cylindrical in shape. Advantageously, the cylindrical duct portion is arranged inside the cylinder formed by the heat exchange surface 754, so that the heat exchange surface 754 surrounds the duct portion.

[0077] The heat transfer fluid of the circuit 71 circulates in the second heat exchanger 75, between an inlet point 751 of the second heat exchanger 75 and an outlet point 752 of the second heat exchanger 75, in a space delimited by an outer surface 753 and an inner surface 754 of the second heat exchanger 75. The inner surface 754 plays a role of heat exchange surface with the first portion of conduit, in particular it implements a heat transfer between a heat transfer fluid circulating in the second heat exchanger 75 and the first portion of conduit.

[0078] In one embodiment, the inlet point 751 of the second heat exchanger 75 and the outlet point 752 of the second heat exchanger 75 are arranged such that the heat transfer fluid flows in a direction opposite to a flow direction of the exhaust gases.

[0079] In addition, the thermal circuit 71 provides means for implementing different circulations of heat transfer fluid intended to cool components, in particular intended to cool the electric motor 20, the combustion engine 10 and the battery 30 during their operation.

[0080] Thus, circuit 71 includes

[0081] - a second set of conduits 102 connecting the outlet point 722 of the first exchanger 72 and the first point A, the second set of conduits 102 being arranged to allow a second circulation of heat transfer fluid for cooling the stack 30 and / or,

[0082] - a third set of conduits 103 connecting the outlet point 722 of the first exchanger 72 and a third point C, located near the combustion engine 10, the third set of conduits 103 being arranged to allow a third circulation of heat transfer fluid for cooling the combustion engine 10.

[0083] In addition, in an embodiment represented by FIG. 6, the motor vehicle 100 is further equipped with an electric motor 20, and the thermal circuit 71 comprises a fourth set of conduits 104 connecting the outlet point 722 and a fourth point D, located near the electric motor 20, the fourth set of conduits 104 being arranged to allow a fourth circulation of heat transfer fluid for cooling the electric motor 20.

[0084] In addition, other fluid circulations are possible, particularly during a time interval preceding the start of one of the two engines.

[0085] Thus, in addition to the first set of conduits 101 previously described, the circuit 71 advantageously comprises other means for preheating one of the motors 10 or 20, or the battery, including:

[0086] - a fifth set of conduits 105 connecting the first point A and the third point C, the fifth set of conduits 105 being arranged to allow a fifth circulation of heat transfer fluid from the cell 30 to the combustion engine 10, and / or

[0087] - a sixth set of conduits 106 connecting the third point C and the first point A, the sixth set of conduits 106 being arranged to allow a sixth circulation of heat transfer fluid from the combustion engine 10 to the cell 30, and / or

[0088] - a seventh set of conduits 107 connecting the second point B and the first point A, the seventh set of conduits 107 being arranged to allow a seventh circulation of heat transfer fluid from the post-treatment system 60 to the stack 30.

[0089] To implement preheating of one of the engines 10 or 20, or of the battery, the thermal system 70 advantageously comprises a means for detecting a forthcoming alternation between use of the combustion engine and use of the electric motor.

[0090] In one embodiment,

[0091] - a first subsystem 110 comprising the battery 30 and the electric motor 20 is controlled by a first digital controller 111, and - a second subsystem 120 comprising the combustion engine 10 and the post-treatment system 60 is controlled by a second digital controller 121.

[0092] The first and second digital controllers 111, 121 are controlled by a central controller 131 which manages the energy management laws of the vehicle. The detection of an upcoming need to start one of the first or second subsystems 110, 120 (for example to optimize consumption) is carried out at the central controller 131. This information is then transmitted to at least one of the first and second digital controllers 111, 121. The digital controller 111, 121 of the system starting soon controls the start of the preheating of said system.

[0093] In this embodiment, the thermal system 70 can communicate with the digital controllers 111, 121 in order to detect an upcoming alternation between use of the combustion engine and use of the electric motor.

[0094] In an advantageous embodiment, the thermal system 70 further comprises the means for implementing a thermal management method according to the invention. In particular, the thermal system 70 comprises a processing unit 76 comprising a microprocessor 77, a memory 78 and communication interfaces 79.

[0095] The thermal system 70, and particularly the microprocessor 77, mainly comprises the following modules which cooperate with each other:

[0096] - a module 771 for thermal management of an operating phase of the battery and the electric motor, this module being able to cooperate with the pump 73 and the three-way valve 731,

[0097] - a module 772 for anticipating an upcoming start of the combustion engine and the post-treatment system, this module being able to cooperate with the second digital controller 121 and the pump 74,

[0098] - a module 773 for thermal management of an operating phase of the combustion engine and the post-treatment system, this module being able to cooperate with the pump 73, the three-way valve 731, the first cut-off valve 732, and the second cut-off valve 733,

[0099] - a module 774 for anticipating an upcoming start-up of the battery and the electric motor, this module being able to cooperate with the first digital controller 111 and the pump 74.

[0100] The motor vehicle 100, in particular the thermal system 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.

[0101] The method includes an iteration on:

[0102] - a first step E1 of thermal management of an operating phase of the battery and the electric motor, then

[0103] - a second stage E2 of anticipation of an upcoming start of the combustion engine and the post-treatment system, then

[0104] - a third stage E3 of thermal management of an operating phase of the combustion engine and the post-treatment system, then

[0105] - a fourth step E4 of anticipation of an upcoming start-up of the battery and the electric motor, the second step E2 comprising an implementation of the first circulation of heat transfer fluid and, optionally, an implementation of the fifth circulation of heat transfer fluid.

[0106] In the first step E1, the first subsystem 110 comprising the battery 30 and the electric motor 20 is started and controlled by the first digital controller 111. In one embodiment, a cooling start order is then received from the first digital controller 111.

[0107] The pump 73 is then put into operation if it was not already started, and the three-way valve 731 is configured to implement the second circulation of fluid 102 between the outlet point 722 of the first heat exchanger 72 and the first point A located near the stack 30, for cooling the stack 30. In addition, the three-way valve 731 is also configured to implement the fourth circulation of fluid 104 between the outlet point 722 of the first heat exchanger 72 and the fourth point D located near the electric motor 20, for cooling the electric motor 20.

[0108] We then continue with step E2 of anticipation of an upcoming start of the combustion engine and the post-treatment system 60. In step E2, we wait for a notification of an upcoming start of the second subsystem 120 comprising the combustion engine 10 and the post-treatment system 60, the notification possibly coming from the second digital controller 121.

[0109] Upon receipt of a notification of an upcoming start-up of the second subsystem 120, the first circulation of heat transfer fluid is implemented between the stack 30 and the post-treatment system 60. For this, the second pump 74 is then put into operation if it has not already been started.

[0110] In an embodiment where the circuit 71 comprises a second heat exchanger 75 according to the embodiment previously described with reference to FIG. 6, the heating of the post-treatment system 60 is then carried out by the passage of the heat transfer fluid between the inlet point 751 of the second heat exchanger 75 and the outlet point 752 of the second heat exchanger 75. In addition, in step E2 it is also possible to implement the fifth circulation of heat transfer fluid between the cell 30 and the combustion engine 10, for heating the combustion engine 10.

[0111] Then, we wait for a notification of a start of the second subsystem 120, the notification possibly coming from the second digital controller 121. When we receive such a notification, we continue with step E3.

[0112] In step E3, the three-way valve 731 is configured to implement the third circulation of heat transfer fluid 103, between the outlet point 722 and the third point C located near the combustion engine 10 for cooling the combustion engine 10. Advantageously, a first cut-off valve 732 is configured so that it prevents the passage of cold coolant near the post-treatment system 60. The implementation of the fifth circulation of heat transfer fluid is also interrupted, to interrupt the heating of the combustion engine 10 by the cell 30.

[0113] Advantageously, the first cut-off valve 732 is closed in order to prevent cooling of the post-treatment system 60.

[0114] If the circuit 71 is implemented according to the third mode previously described with reference to FIG. 6, the second cut-off valve 733 can also be closed to prevent the post-treatment system from transmitting too much heat to the heat transfer fluid. In cases where the temperature reached by the post-treatment system 60 is very significantly higher than an operating temperature of the cell 30, then the purge system 734 is activated in order to store the heat transfer fluid which has been heated by the post-treatment system 60. The fluid thus stored will be reinjected later when the post-treatment system needs to be heated again before starting up.

[0115] We then continue with step E4 of anticipation of an upcoming start-up of the battery. In step E4, we wait for a notification of an upcoming start-up of the first subsystem 110 comprising the battery and the electric motor, the notification possibly coming from the first digital controller 111.

[0116] Upon receipt of a notification of an upcoming start of the first subsystem 110, the sixth circulation of heat transfer fluid is implemented between the heat engine 10 and the battery 30. For this, the second pump 74 is started if it has not yet been started.

[0117] In addition or alternatively, the seventh circulation of heat transfer fluid is implemented between the post-treatment system 60 and the stack 30. For this, if the circuit 71 comprises a purge system 734 and if the purge system 734 is activated, the purge system 734 is deactivated. Furthermore, if the second cut-off valve 733 is closed, it is opened.

[0118] Then we loop back to step E1.

[0119] Table 1 provides a summary of the different heat transfer fluid circulations that can be implemented by the thermal circuit according to the invention depending on an alternation between use of a combustion engine 10 and use of an electric motor 20.

[0120] [Table 1]

[0121]

[0122] The first line of Table 1 defines different driving phases of the motor vehicle 100:

[0123] - a first phase of driving with the electric motor, without anticipation of a future use of the combustion engine, corresponding to step E1,

[0124] - a second phase of driving with the electric motor, with anticipation of a future use of the combustion engine, corresponding to step E2,

[0125] - a third phase of driving with the combustion engine, without anticipation of a future use of the electric motor, corresponding to step E3,

[0126] - a fourth phase of driving with the combustion engine, with anticipation of a future use of the electric motor, corresponding to step E4.

[0127] The second line of Table 1 describes the heat transfer fluid circulations implemented for the thermal management of the stack, according to the four driving phases previously listed.

[0128] The third line of Table 1 describes the heat transfer fluid circulations implemented for the thermal management of the electric motor, according to the four driving phases previously listed.

[0129] The fourth row of Table 1 describes the heat transfer fluid circulations implemented for the thermal management of the combustion engine, according to the four driving phases previously listed. The fifth row of Table 1 describes the heat transfer fluid circulations implemented for the thermal management of the aftertreatment system, according to the four driving phases previously listed.

[0130] The sixth line of Table 1 describes the operation of the purge system 734, according to the four driving phases previously listed.

[0131] In an embodiment not detailed in this document, the combustion engine 10 and the electric motor 20 could be used simultaneously.

[0132] Finally, the thermal system according to the invention makes it possible to integrate all the thermal needs of the two engines, the battery and the post-treatment system by implementing a single heat transfer fluid circuit. The single circuit makes it possible to cool one and / or the other of the two engines, as well as the battery during operation of the electric motor. The single circuit also makes it possible to preheat the post-treatment system, the thermal engine and / or the battery before they are started, in particular when the engines are used alternately.

[0133] The preheating implemented by the thermal system makes it possible to reduce a temperature rise phase of the post-treatment system; it therefore makes it possible to effectively reduce nitrogen oxide emissions from the thermal engine, right from the start of the thermal engine.

[0134] The preheating implemented by the thermal system also makes it possible to reduce the duration of a battery temperature rise phase, a phase during which the high-voltage battery must be used. Thus, thanks to the thermal system, when starting the battery and the electric motor, the duration of use of the high-voltage battery is reduced, which improves the vehicle's energy efficiency.

Claims

CLAIMS 1. Thermal system (70) for a motor vehicle (100), the vehicle being equipped with an electric motor (20) and an internal combustion engine (10), characterized in that it comprises a fuel cell (30) capable of powering the electric motor (20), a post-treatment system (60) for the exhaust gases of the combustion engine (10) and a circuit (71) comprising a first set of conduits (101), the first set of conduits (101) being arranged to allow a first circulation of a heat transfer fluid from the fuel cell (30) to the post-treatment system (60).

2. Thermal system (70) according to the preceding claim, characterized in that it comprises a first heat exchanger (72) comprising an inlet point (721) for the fluid in the first heat exchanger (72) and an outlet point (722) for the fluid out of the first heat exchanger (72), and in that the circuit (71), the first set of conduits (101) of which connects a first point (A) located near the fuel cell and a second point (B) located near the post-treatment system (60), also comprises: - a second set of conduits (102) connecting the outlet point (722) and the first point (A), the second set of conduits (102) being arranged to allow a second circulation of heat transfer fluid for cooling the stack (30) and / or, - a third set of conduits (103) connecting the outlet point (722) and a third point (C), located near the combustion engine (10), the third set of conduits (103) being arranged to allow a third circulation of heat transfer fluid for cooling the combustion engine (10) and / or, - a fourth set of conduits (104) connecting the outlet point (722) and a fourth point (D), located near the electric motor (20), the fourth set of conduits (104) being arranged for allow a fourth circulation of heat transfer fluid for cooling the electric motor (20).

3. Thermal system (70) according to one of the preceding claims, characterized in that the circuit (71) further comprises: - a fifth set of conduits (105) connecting the first point (A) and the third point (C), the fifth set of conduits (105) being arranged to allow a fifth circulation of heat transfer fluid from the cell (30) to the combustion engine (10), and / or - a sixth set of conduits (106) connecting the third point (C) and the first point (A), the sixth set of conduits (106) being arranged to allow a sixth circulation of heat transfer fluid from the combustion engine (10) to the cell (30), and / or - a seventh set of conduits (107) connecting the second point (B) and the first point (A), the seventh set of conduits (107) being arranged to allow a seventh circulation of heat transfer fluid from the post-treatment system (60) to the stack (30).

4. Thermal system (70) according to one of the preceding claims, characterized in that the fuel used by the cell (30) is dihydrogen, and / or in that the cell (30) is of the proton exchange membrane type, and / or in that the cell is of the high temperature proton exchange membrane type.

5. Thermal system (70) according to one of the preceding claims, characterized in that the heat transfer fluid is a synthetic heat transfer fluid in liquid phase and / or in that the heat transfer fluid is effective over a temperature range greater than or equal to 100 degrees, or even greater than or equal to 200 degrees, in particular over a temperature range from -40°C to 200°C, or even over a temperature range from -85°C to 260°C.

6. Thermal system (70) according to one of the preceding claims, the post-treatment system (60) comprising a portion of conduit (61) exhaust gas flow containing a catalyst (62) characterized in that the circuit (71) comprises a second heat exchanger (75) for implementing a heat transfer between a heat transfer fluid circulating in the second heat exchanger (75) and the duct portion (61), in that the duct portion (61) and a heat exchange surface (754) of the second heat exchanger (75) are cylindrical in shape, and the heat exchange surface (754) surrounds the duct portion (61), and / or in that the heat transfer fluid circulates in a direction opposite to a flow direction (759) of the exhaust gases in the duct portion.

7. Method for thermal management of a motor vehicle (100) equipped with a fuel cell (30), an electric motor (20), a combustion engine (10), a post-treatment system (60) for the exhaust gases of the combustion engine (10), and a thermal system (70) according to one of the preceding claims, characterized in that it comprises an iteration of the following steps: - a first step (E1) of thermal management of an operating phase of the battery and the electric motor, then - a second stage (E2) of anticipation of an upcoming start of the combustion engine and the post-treatment system, then - a third stage (E3) of thermal management of an operating phase of the combustion engine and the post-treatment system, then - a fourth step (E4) of anticipation of an upcoming start of the stack, and in that the second step (E2) comprises an implementation of the first circulation of heat transfer fluid and, optionally, an implementation of the fifth circulation of heat transfer fluid.

8. Thermal management method according to the preceding claim, characterized in that - the first stage (E1) and the second stage (E2) comprise an implementation of the second circulation and the fourth circulation of heat transfer fluid, and / or - the third step (E3) and the fourth step (E4) comprise an implementation of the third circulation of heat transfer fluid, and / or - the fourth step (E4) includes an implementation of the sixth circulation and / or the seventh circulation of heat transfer fluid.

9. Thermal management system (70) according to one of claims 1 to 6, the system comprising hardware and / or software elements (10, 20, 30, 40, 50, 60, 71, 72, 73, 74, 75, 76, 77, 78, 79, 721, 722, 731, 732, 733, 734, 771, 772, 773, 774) implementing the method according to one of claims 7 or 8, in particular hardware elements (10, 20, 30, 40, 50, 60, 71, 72, 73, 74, 75, 76, 77, 78, 79, 721, 722, 731, 732, 733, 734) and / or software designed to implement a method according to one of the preceding claims, and / or the device comprising means for implementing the method according to one of the preceding claims.

10. Motor vehicle (100) equipped with a thermal management thermal system (70) according to the preceding claim and / or according to one of claims 1 to 6.

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