Thermal management system and method for a motor vehicle comprising a hydrogen powertrain

Abstract

TITLE: Thermal Management System and Method for a Motor Vehicle Comprising a Hydrogen Powertrain. Thermal management system (2) for a motor vehicle (1) comprising a hydrogen powertrain (3), including a primary boost circuit (4) with a primary cooling module (42), a secondary circuit (5) for circulating a heat transfer fluid (RF) with a secondary cooling module (51), the system further comprising a heat exchanger configured to implement heat exchange between the boost airflow (FAS) circulating in the primary circuit (4) and the heat transfer fluid (RF) circulating in the secondary circuit (5). Abstract Figure: Figure 1

Description

Title of the invention: System and method for thermal management of a motor vehicle comprising a hydrogen powertrain

[0001] The invention relates to a thermal management system for a motor vehicle, in particular one equipped with a hydrogen powertrain. The invention also relates to a motor vehicle equipped with said system. The invention also relates to a method for thermal management of a motor vehicle.

[0002] In a context where manufacturers are turning to low-emission vehicles, internal combustion engines are suitable for implementing hydrogen power, i.e. using dihydrogen as fuel. However, hydrogen powertrains are subject to different design constraints than combustion engines using gasoline or diesel.

[0003] In particular, in order to achieve a high level of performance, for example targeted in sports applications, it is necessary to take into consideration the fact that hydrogen has a lower energy density than that of gasoline. It is known to compensate for this deficit by operating at higher temperatures but also by working on the efficiency of the engine.

[0004] The implementation of higher combustion temperatures requires the development of more efficient thermal management systems that meet the requirements for maintaining the engine components, i.e. the durability of its components, but also the performance requirements, i.e. the ability to withstand high maximum power levels repeatedly. Known hydrogen-powered vehicles are equipped with cooling systems comprising a circuit in which a heat transfer fluid circulates, heating up in contact with the vehicle components and cooling down by passing through a heat exchanger. The system further comprises a circuit configured to allow the circulation of a cooling fluid, also referred to as a water circuit, making it possible to limit the rise in temperature of the cylinder head of the powertrain.A disadvantage of known systems lies in the significant size and bulkiness of the heat exchanger used, thereby limiting the performance of the vehicle and impacting its aerodynamics.

[0005] The invention falls within this context and aims to provide a system and a method for thermal management of a motor vehicle which overcomes the above drawbacks. In particular, the invention proposes a thermal management system for a motor vehicle comprising

[0006] The invention relates to a thermal management system for a motor vehicle equipped with a hydrogen powertrain, the thermal management system including: - at least one primary supercharging circuit capable of allowing the circulation of a flow of supercharging air, said circuit comprising a turbocharger, a primary cooling module comprising a primary set of controlled flaps and a primary heat exchanger configured to implement a heat exchange between the flow of supercharging air and an air flow outside the vehicle; - at least one secondary circuit for circulating a heat transfer fluid comprising a hydrogen powertrain and a secondary cooling module comprising a secondary set of controlled flaps and a heat exchanger configured to implement a heat exchange between the heat transfer fluid and the air flow outside the vehicle.

[0007] The system further comprises a means for controlling the primary set of flaps and the secondary set of flaps and at least one secondary heat exchanger configured to implement a heat exchange between the flow of supercharging air circulating in the at least one primary circuit and the heat transfer fluid circulating in the at least one secondary circuit.

[0008] In particular, the at least one secondary heat exchanger: - is arranged downstream of the turbocharger and upstream of the primary heat exchanger in a direction of circulation of the supercharging air flow; and - is arranged downstream of the powertrain and upstream of at least one heat exchanger in a direction of circulation of the heat transfer fluid.

[0009] According to an exemplary embodiment, the at least one primary cooling module is at least partly arranged upstream of the at least one secondary cooling module in a direction of circulation of the external air flow, the primary set of flaps being arranged so as to regulate the circulation of at least a portion of the external air flow intended to circulate successively through the primary heat exchanger then the heat exchanger.

[0010] According to a particular exemplary embodiment, the thermal management system comprises: - a plurality of primary supercharging circuits, each being capable of allowing the circulation of a flow of supercharging air specific to it and each of said circuits comprising a turbocharger, a primary cooling module comprising a primary set of flaps and a primary heat exchanger configured to implement a heat exchange between the flow of supercharging air specific to said circuit and an air flow external to the vehicle; - a plurality of secondary circuits for circulating a heat transfer fluid, each comprising at least part of the powertrain and a cooling module secondary system comprising a secondary set of flaps and a heat exchanger configured to implement a heat exchange between the heat transfer fluid and the air flow outside the vehicle.

[0011] The system then further comprises a plurality of secondary heat exchangers, each being configured to implement a heat exchange between the flow of supercharging air circulating in one of the primary circuits and the heat transfer fluid circulating in one of the secondary circuits.

[0012] In other words, in such an exemplary embodiment, the at least one primary supercharging circuit, also referred to as the first primary supercharging circuit, comprises a first turbocharger, a first primary cooling module comprising a first primary set of controlled flaps and a first primary heat exchanger, and the at least one secondary circuit for circulating heat transfer fluid, also referred to as the first secondary circuit, comprises the powertrain, a first secondary cooling module, comprising a first secondary set of controlled flaps and a first heat exchanger.

[0013] Also in such an exemplary embodiment, the thermal management system comprises: - a second primary supercharging circuit comprising a second turbocharger, a second primary cooling module comprising a second primary set of controlled flaps and a second primary heat exchanger configured to implement a heat exchange between the flow of supercharging air circulating in said second primary circuit and an air flow outside the vehicle; - a second secondary heat transfer fluid circulation circuit, comprising the powertrain, a second secondary cooling module, comprising a second secondary set of controlled flaps and a second heat exchanger; and - the at least one secondary heat exchanger, referred to as the first secondary heat exchanger, configured to implement a heat exchange between the flow of supercharging air circulating in the first primary circuit and the heat transfer fluid circulating in the first secondary circuit, and a second secondary heat exchanger, configured to implement a heat exchange between the flow of supercharging air circulating in the second primary circuit and the heat transfer fluid circulating in the second secondary circuit.

[0014] For example, the management system comprises at least one pump arranged so as to be common to the plurality of secondary circuits for circulating a heat transfer fluid.

[0015] The invention also relates to a motor vehicle comprising the system of thermal management according to the invention.

[0016] The invention also relates to a method for thermal management of a motor vehicle according to the invention, the vehicle being equipped with at least one primary temperature sensor, capable of measuring a temperature of the supercharging air flow at at least one point of the at least one primary circuit, and a secondary temperature sensor configured to measure a temperature of the heat transfer fluid at at least one point of the at least one secondary circuit, the method comprising: - a step of measuring a temperature of the supercharging air flow and the heat transfer fluid via the primary temperature sensor and the secondary temperature sensor respectively; - a step of determining a thermal management mode to be applied based on the measured temperatures; - a step of applying the thermal management mode determined by adjusting a degree of opening of at least the primary set of flaps and / or the secondary set of flaps by means of the control means, the primary set of flaps being open when the temperature of the supercharging air flow is greater than or equal to a first primary temperature threshold and / or the secondary set of flaps being open when the temperature of the heat transfer fluid is greater than or equal to a first secondary temperature threshold.

[0017] In particular, the at least one primary cooling module comprises a primary motor-fan unit and the at least one secondary cooling module comprises a secondary motor-fan unit, the step of applying the thermal management mode comprising adjusting an operating mode of the primary motor-fan unit when the temperature of the supercharging air flow is greater than or equal to a second primary temperature threshold, greater than the first primary temperature threshold, and / or adjusting an operating mode of the secondary motor-fan unit when the temperature of the heat transfer fluid is greater than or equal to a second secondary temperature threshold, greater than the first secondary temperature threshold.

[0018] In particular, the step of applying the thermal management mode to be applied comprises limiting the torque of the powertrain when the temperature of the supercharging air flow is greater than or equal to a third primary temperature threshold.

[0019] The invention finally extends to a computer program product comprising program code instructions recorded on a computer-readable medium for implementing the steps of the thermal management method according to the invention when said program operates on a computer.

[0020] Other details, features and advantages will become more apparent upon reading of the detailed description given below, for informational and non-limiting purposes, in relation to the various examples of embodiment illustrated in the following figures:

[0021] [Fig.l] is a simplified schematic representation of an exemplary embodiment of a thermal management system implemented in a “small displacement” type vehicle.

[0022] [Fig.2] is a schematic representation of an exemplary embodiment of a vehicle comprising the thermal management system illustrated in [Fig.l].

[0023] [Fig. 3] is a schematic representation of a first example of an arrangement of separate exchangers included in the thermal management system illustrated in [Fig. 1] or 2.

[0024] [Fig.4] is a schematic representation of an exemplary embodiment of a vehicle comprising a separate arrangement of exchangers of the thermal management system illustrated in [Fig.l].

[0025] [Fig.5] is a schematic representation of the exchanger arrangement illustrated in [Fig.4].

[0026] [Fig. 6] is a simplified schematic representation of an example embodiment of the thermal management system implemented in a “large displacement” type vehicle.

[0027] [Fig.7] is a schematic representation of an exemplary embodiment of a vehicle comprising the thermal management system illustrated in [Fig.6].

[0028] [Fig.8] is a schematic representation of another example of an arrangement of separate exchangers included in the thermal management system illustrated in [Fig.6] or 7.

[0029] [Fig.9] is a flowchart detailing an example of execution of the thermal management method according to the invention.

[0030] [Fig. 10] is a flowchart detailing an example of execution of the thermal management method according to the invention.

[0031] Figures 1 to 8 schematically illustrate a motor vehicle 1 equipped with an embodiment of a thermal management system 2 according to the invention. The vehicle 1 can be of any type, that is to say it can be a private vehicle, a sports vehicle, a utility vehicle, a truck or a bus.

[0032] In particular, the vehicle 1 comprises a hydrogen powertrain 3, i.e. a combustion engine using dihydrogen as fuel. Conventionally, the powertrain 3 comprises a cylinder head 31 and at least one cylinder in which a movable piston, not shown, is moved. It should be noted that, preferably, the powertrain 3 comprises a plurality of cylinders. According to an exemplary embodiment illustrated in FIGS. 1 to 5, the invention can be applied to a vehicle of the “small displacement” type. Alterna tively, according to a particular embodiment described below with reference to figures 6 to 8, the invention can be applied to a vehicle 1 of the “large displacement” or sports car type, in particular equipped with a powertrain 3 of the “V6” type, that is to say comprising six cylinders arranged in a “V” configuration formed by two rows of three cylinders.

[0033] Throughout the description below, the terms “upstream”, “downstream”, “inlet” and “outlet” refer to a direction of circulation of a fluid specific to a circuit considered, illustrated by arrows. Also, the terms “first”, “second” or even “primary” and “secondary” are intended to distinguish similar components and not to define a hierarchy within the present invention.

[0034] Generally speaking, the thermal management system 2 according to the invention comprises at least one primary supercharging circuit 4, capable of allowing the circulation of a supercharging air flow FAS, and at least one secondary circuit 5 for circulating a heat transfer fluid FR.

[0035] In the example illustrated in Figures 1 to 5, implemented in a particular vehicle 1, or of the “small displacement” type, the powertrain 3 comprises in particular four cylinders or less. In a known manner, not detailed, the supercharging air flow FAS is intended to be sent to an intake manifold, not shown, of the powertrain 3 in order to be injected into a combustion chamber delimited by the at least one cylinder, or, as illustrated, a plurality of combustion chambers, each of said chambers being delimited by one of the cylinders. The supercharging air flow FAS is then evacuated via an exhaust manifold. The at least one primary supercharging circuit 4 is thus an open circuit passing through the powertrain 3.

[0036] The at least one primary circuit 4 allows the circulation and thermal management of the supercharging air flow FAS. It comprises a turbocharger 41, in particular arranged upstream of the power unit 3 in a direction of circulation of the supercharging air flow FAS, capable of increasing the pressure of the supercharging air flow FAS.

[0037] The at least one primary circuit 4 further comprises a primary cooling module 42 comprising at least one primary set of controlled flaps 43 and a primary heat exchanger 44 configured to implement a heat exchange between the charge air flow FAS and an air flow FE outside the vehicle 1. The primary heat exchanger 44 has in particular the function of a charge air cooler, also called RAS. By external air flow FE is meant an air flow coming from the environment outside the vehicle 1 and which can, for example, be brought into the engine compartment of the vehicle 1 from the front, as shown in FIGS. 1 to 5, for example at the level of an air flow supply grille exterior FE.

[0038] Also, preferably, the primary cooling module 42 comprises a primary motor-fan unit 45, also known as GMV, comprising a fan driven by an electric motor.

[0039] The at least one secondary circulation circuit 5 is configured to allow the circulation of a heat transfer fluid FR, also referred to as a cooling fluid, such as glycolated water. The at least one secondary circulation circuit 5 is configured to allow the heat treatment of at least a portion of the powertrain 3. It thus comprises the powertrain 3, in particular the cylinder head 31, and allows the passage of the heat transfer fluid FR through at least a portion thereof. Also, the at least one secondary circulation circuit 5 comprises at least one pump 32.

[0040] The at least one secondary circuit 5 also comprises a secondary cooling module 51, comprising a secondary set of controlled flaps 52 and a heat exchanger 53 configured to implement a heat exchange between the heat transfer fluid FR and the air flow FE outside the vehicle 1. The heat exchanger has in particular the function of a radiator, that is to say that it is configured so that the heat transfer fluid FR transfers calories to the air flow FE outside, thus allowing the cooling of said fluid and, by extension, of all or part of the components arranged on the at least one secondary circuit 5.

[0041] The at least one secondary circuit 5 is a closed circuit, fluidically independent of the at least one primary circuit 4 so that the heat transfer fluid FR is not caused to mix with the supercharging air flow FAS or to circulate in the at least one primary circuit 4 and vice versa. It should also be noted, as further detailed below, that separate parts of the outside air flow FE can implement a heat exchange with the primary heat exchanger 44 and the heat exchanger 53 or, alternatively, the same part of the outside air flow FE can successively pass through the primary heat exchanger 44 and the heat exchanger 53.

[0042] Also, preferably, the secondary cooling module 51 comprises a secondary motor-fan unit 54 comprising a fan driven by an electric motor. Alternatively, in particular for an arrangement of the thermal management system 2 as illustrated in FIGS. 2 and 3, further explained below, the primary cooling module 42 and the secondary cooling module 51 comprise a common motor-fan unit.

[0043] The thermal management system 2 according to the invention further comprises a means 6 for controlling the primary cooling module 42 and the secondary cooling module 51. Such a control means 6 is in particular capable, at a given instant, of modifying the degree of opening of the primary set of shutters 43 and / or of the secondary set of flaps 52 separately, respectively in order to regulate the flow of outside air FE circulating through the primary heat exchanger 44 and / or the heat exchanger 53 respectively. For each set of controlled flaps considered, the control means 6 is capable of moving all or part of the flaps of said set between a “closed” configuration, preventing or limiting the passage of the flow of outside air FE through at least part of the associated exchanger considered, and an “open” configuration. It is understood that the different flaps can also be arranged in an intermediate configuration corresponding to a position between the “open” configuration and the “closed” configuration.

[0044] Finally, the thermal management system 2 comprises at least one secondary heat exchanger 7 configured to implement a heat exchange between the charge air flow FAS circulating in the at least one primary circuit 4 and the heat transfer fluid FR circulating in the at least one secondary circuit 5. The presence of the secondary heat exchanger 7 advantageously makes it possible to ensure a double stage of thermal management, in particular cooling, of the charge air flow FAS while limiting the dimensions and the bulk of the primary heat exchanger 44 in a suitable manner in order to comply with the space constraints of the vehicle 1 on the one hand and / or in order to optimize the performance of the vehicle 1, for example in the context of sporting use. Here, the term "stage" means thermal management taking place in two stages, by means of two distinct heat exchangers, physically separated from each other.

[0045] Indeed, in the case of a hydrogen powertrain 3, the thermal management implemented at the supercharging circuit, namely here the at least one primary circuit 4, is essential to provide the required engine power. The temperature of the supercharging air flow FAS leaving the turbocharger 41 intended to be sent to the intake manifold of the powertrain 3 being too high to ensure such performance, the implementation of two “stages” of thermal management of the supercharging air flow FAS makes it possible to ensure a desired level of performance while maintaining a suitable level of size and limiting the dimensions of the at least one primary heat exchanger 44.

[0046] Preferably, as illustrated in [Fig. 1], the at least one secondary heat exchanger 7 is arranged, within the at least one primary circulation circuit 4, downstream of the turbocharger 41 and upstream of the primary heat exchanger 44 in a direction of circulation of the supercharging air flow FAS. In this way, the at least one secondary heat exchanger 7 makes it possible to provide a first thermal treatment, in particular cooling, of the compressed supercharging air flow FAS leaving the turbocharger 4L. The secondary heat exchanger 7 thus implements the first thermal management stage within the at least one primary circulation circuit 4.

[0047] Additionally or alternatively, the at least one secondary heat exchanger 7 is arranged, within the secondary circulation circuit 5, downstream of the power unit 3, in particular of at least one part of the cylinder head 31 of the power unit 3, and upstream of the at least one heat exchanger 53 in a direction of circulation of the heat transfer fluid FR.

[0048] The “first stage” of thermal management is thus ensured by the at least one secondary heat exchanger 7 by implementing an indirect heat exchange with the outside air flow FE via the at least one secondary circuit 5 for circulating the heat transfer fluid FR. The “second stage” of thermal management, configured to be executed following the “first stage” according to the direction of circulation of the supercharging air flow FAS, is implemented by a direct heat exchange with the outside air flow FE via the at least one secondary heat exchanger 7. Such an arrangement of the at least one secondary exchanger 7 is particularly suitable in the case of high temperatures of the supercharging air flow FAS, since the at least one secondary circuit 5 has a better heat exchange capacity in such situations.

[0049] Figures 2 to 5 schematically illustrate different examples of arrangements of the at least one heat exchanger 53 and the at least one primary heat exchanger 44 within the vehicle 1 on the one hand, and relative to each other on the other hand. By convention in the description below, the direction in which the motor vehicle 1 moves in a straight line is defined as being the longitudinal direction X, oriented from front to rear. The direction perpendicular to the longitudinal direction and located in a plane parallel to the ground is called the transverse direction Y. The direction perpendicular to the directions X and Y is called the vertical direction Z. Thus, a direct reference XYZ is defined, represented in the figures requiring it.

[0050] According to particular exemplary embodiments, illustrated in Figures 2 to 5, the at least one secondary cooling module 51 is arranged on the front face of the vehicle 1, for example in a front half of the vehicle 1, in particular at the level of the compartment housing the powertrain 3. According to an exemplary embodiment, as illustrated in Figures 2 and 3, the at least one primary cooling module 42 is arranged upstream of the secondary cooling module 51 of the vehicle 1 in a direction of circulation of the outside air flow FE. Alternatively, the at least one secondary cooling module 51 and the at least one primary cooling module 42 may be adjacent, in particular arranged next to each other, in the front half of the vehicle as shown in Figures 4 and 5.

[0051] More particularly according to a first exemplary embodiment, illustrated in [Fig.2] or 3, the at least one primary cooling module 42 is at least partly arranged upstream of the at least one secondary cooling module 51 in a direction of circulation of the outside air flow FE so that the same portion of the outside air flow FE circulates successively through the at least one primary heat exchanger 44 of the at least one primary cooling module 42 then the at least one heat exchanger 53 of the at least one secondary cooling module 51. In other words, in such an exemplary embodiment, the at least one primary set of flaps 43, included in the at least one primary cooling module 42 is arranged so as to regulate the circulation of at least a portion of the outside air flow FE intended to circulate successively through the at least one primary heat exchanger 44 then the at least one heat exchanger 53.For example, the at least one primary heat exchanger 44 is thus at least partly aligned, along the longitudinal direction X, with the at least one heat exchanger 53 so that the same axis parallel to the longitudinal direction passes through said exchangers. Conversely, the at least one secondary set of flaps 52 is arranged so as to regulate the circulation of a portion of the air flow intended to circulate only through the heat exchanger 53.

[0052] Alternatively, as illustrated in [Fig. 4], the at least one primary cooling module 42 and the at least one secondary cooling module 51 are arranged so that distinct portions of the outside air flow FE circulate through the at least one heat exchanger 53 and the at least one primary heat exchanger 44. The at least one secondary set of flaps 52, included in the at least one secondary cooling module 51, and the at least one primary set of flaps 43, included in the at least one primary cooling module 42, then make it possible to regulate the circulation of distinct portions of the outside air flow FE and, consequently, to separately regulate the heat exchange implemented at the level of the at least one heat exchanger 53 and the at least one primary heat exchanger 44.For example, the at least one heat exchanger 53 and the at least one primary heat exchanger 44 are offset relative to each other along the transverse direction Y.

[0053] Optionally still, the vehicle 1 and / or the thermal management system 2 according to the invention comprises at least one primary temperature sensor 46, capable of measuring a temperature of the supercharging air flow FAS at at least one point, and at least one secondary temperature sensor 55 configured to measure a temperature of the heat transfer fluid FR at at least one point.

[0054] For example, the at least one primary temperature sensor 46 is arranged downstream of the turbocharger 41. In particular, preferably, the at least one primary temperature sensor 46 is capable of measuring the temperature of the supercharging air flow FAS leaving the at least one primary heat exchanger 44, by example at the intake manifold of the power unit 3. Likewise, for example, the at least one secondary sensor 55 is arranged downstream of the at least one heat exchanger 53, for example before the heat transfer fluid FR enters the cylinder head 31 of the power unit 3.

[0055] Thus, according to an example of operation of the thermal management system 2 as described above, the charge air flow FAS is sent into the at least one turbocharger 41 in which it is compressed. The outgoing charge air flow FAS has a higher pressure and temperature than at its inlet to the turbocharger 41. The charge air flow FAS is then sent to the at least one secondary heat exchanger 7 at which a heat exchange is implemented between said air flow and the heat transfer fluid FR circulating in the at least one secondary circuit 5 without them mixing. The heat transfer fluid FR captures calories from the charge air flow FAS so that the charge air flow FAS leaving the at least one secondary heat exchanger 7 has a lower temperature than that of the charge air flow FAS entering said exchanger.Conversely, the heat transfer fluid FR leaving the at least one secondary heat exchanger 7 has a higher temperature than the incoming fluid.

[0056] The charge air flow FAS is then sent to the at least one primary heat exchanger 44. The at least one primary set of flaps 43 is configured to be open in a suitable configuration, via the control means 6, according to the thermal cooling requirement of the charge air flow FAS. Similarly, the primary motor-fan unit 45 is configured to be activated or not, via said control means 6, according to the requirement. When it is necessary to cool the charge air flow FAS leaving the secondary heat exchanger 7 for example, the at least one primary set of flaps 43 is arranged in an “open” configuration or in an intermediate configuration so that the air flow FE outside the vehicle 1 circulates through the at least one primary heat exchanger 44 and captures calories from the charge air flow FAS.The charge air flow FAS leaving the at least one primary heat exchanger 44 is thus cooled to a suitable temperature and can be sent to the powertrain 3.

[0057] At the same time, the heat transfer fluid FR leaving the at least one secondary heat exchanger 7 is sent to the at least one heat exchanger 53. The at least one secondary set of flaps 52 is configured to be moved into a configuration adapted according to the thermal cooling requirement of the heat transfer fluid FR by means of the control means 6. The same applies to the secondary motor-fan unit 54 which can be activated or not according to the requirement. When it is necessary to cool the heat transfer fluid FR leaving the secondary heat exchanger 7 for example, the at least one secondary set of flaps 52 is arranged in an “open” configuration or in an intermediate configuration so that the flow of air FE outside the vehicle 1 circulates through the at least one heat exchanger 53 and captures calories from the heat transfer fluid FR. The heat transfer fluid FR leaving the at least one heat exchanger 7 is thus cooled and can be sent into the powertrain 3, particularly into the cylinder head 31, thus allowing it to be cooled.

[0058] As illustrated in Figures 6 to 8, the management system according to the invention can also be extended to sports vehicles 1 or of the “large displacement” type. In the example illustrated, the powertrain 3 is for example of the “V6” type and comprises six cylinders arranged in a “V”.

[0059] In such an exemplary embodiment, the thermal management system 2 according to the invention comprises: - a plurality of primary supercharging circuits 4, each being capable of allowing the circulation of a supercharging air flow FAS which is specific to it and each of said circuits comprising a turbocharger 41, a primary cooling module 42 comprising a primary set of controlled flaps 43 and a primary heat exchanger 44 configured to implement a heat exchange between the supercharging air flow FAS specific to said circuit and an external air flow FE to the vehicle 1 as described above; - a plurality of secondary circuits 5 for circulating a heat transfer fluid FR, independent of one another, each being connected to the powertrain 3 and comprising a secondary cooling module 51 comprising a secondary set of flaps 52 and a heat exchanger 53 configured to implement a heat exchange between the heat transfer fluid FR and the flow of air FE outside the vehicle 1.

[0060] In such an embodiment, the thermal management system 2 further comprises a plurality of secondary heat exchangers 7, each being configured to implement a heat exchange between the supercharging air flow FAS circulating in one of the primary circuits 4 and the heat transfer fluid FR circulating in one of the secondary circuits 5.

[0061] The preceding description, made with reference to a thermal management system 2 comprising a single primary supercharging circuit 4 and a single secondary circuit 5 of heat transfer fluid FR, applies here mutatis mutandis. Note that, hereinafter, the at least one primary circuit 4, the at least one secondary circuit 5 and the various components described above will be preceded by “first” so as to distinguish them from a “second” component or circuit of the same type. The present system thermal management 2 comprises, generally and unless otherwise stated, a duplication of the primary circuit 4 and secondary circuit 5 previously described so as to comprise two circuits of each type whose operation is separate.

[0062] Also, in more detail, the thermal management system 2 illustrated in Figures 6 to 8 comprises a primary supercharging circuit 4, hereinafter referred to as the first primary supercharging circuit 4a, configured to allow the circulation of a first flow of supercharging air FAS1 and comprising a first turbocharger 41a, a first primary cooling module 42a comprising a first primary set of flaps 43a and a first primary heat exchanger 44a. The system also comprises at least one secondary circuit 5 for circulating heat transfer fluid FR, hereinafter referred to as the first secondary circuit 5a, comprising a portion of the powertrain 3, a first secondary cooling module 51a, comprising a first secondary set of flaps 52a and a first heat exchanger 53a.

[0063] The thermal management system 2 further comprises a second primary supercharging circuit 4b configured to allow the circulation of a second supercharging air flow FAS2 and comprising a second turbocharger 41b, a second primary cooling module 42b comprising a second primary set of flaps 43b and a second primary heat exchanger 44b configured to implement a heat exchange between the supercharging air flow FAS circulating in said second primary circuit 4b and an external air flow FE to the vehicle 1. The system also comprises a second secondary circuit 5b for circulating heat transfer fluid FR, comprising a part of the powertrain 3, a second secondary cooling module 51b, comprising a second secondary set of flaps 52b and a second heat exchanger 53b.

[0064] Note that the second primary supercharging circuit 4b may be identical to or distinct from the first primary supercharging circuit 4a. Preferably, said circuits have a similar architecture. The same applies to the first secondary circulation circuit 5a and the second secondary circulation circuit 5b.

[0065] The thermal management system 2 also comprises at least one secondary heat exchanger 7, referred to as the first secondary heat exchanger 7a, configured to implement a heat exchange between the charge air flow FAS 1 circulating in the first primary circuit 4a and the heat transfer fluid FR circulating in the first secondary circuit 5a. The thermal management system 2 finally comprises a second secondary heat exchanger 7b, configured to implement a heat exchange between the charge air flow FAS2 circulating in the second primary circuit 4b and the heat transfer fluid FR circulating in the second secondary circuit 5b.

[0066] Additionally, the thermal management system 2 comprises at least one pump 32. According to a preferred embodiment, illustrated, the system comprises a pump 32 common to the first secondary circuit 5a and to the second secondary circuit 5b for circulating the heat transfer fluid FR in order to limit the space requirement generated and the costs of the system. Alternatively, each of the secondary circuits may comprise a pump 32 specific to it.

[0067] Also, each of the primary circuits 4 and the secondary circuits 5 may respectively comprise primary temperature sensors 46, secondary temperature sensors 55, primary motor-fan units 45 and / or secondary motor-fan units 54 as described above.

[0068] Preferably, the first heat exchanger 53a and the second heat exchanger 53b are arranged in the front half of the vehicle, in particular on the front face of the vehicle 1, while the first primary heat exchanger 44a and the second primary heat exchanger 44b are arranged in a rear half of the vehicle 1. For example, the first heat exchanger 53a and the first primary heat exchanger 44a are arranged on a right side of the vehicle 1 while the second heat exchanger 53b and the second primary heat exchanger 44b are arranged on a left side of the vehicle 1, as specified in [Fig. 7] or 8. Note that the second primary cooling module 42b is not illustrated in [Fig. 8] for the sake of clarity.

[0069] The invention also relates to a method 100 for thermal management of the motor vehicle 1. In other words, such a method can be considered as a method for operating or using a vehicle 1 equipped with the thermal management system 2 according to the invention. Alternatively, such a method corresponds to a method for operating or using the thermal management system 2. Such a method can be applied to a thermal management system 2 as defined in FIGS. 1 to 5, comprising a single primary circulation circuit 4 and a single secondary circulation circuit 5, here implemented in a small cylinder capacity, or to a thermal management system 2 as defined in FIGS. 6 to 8, comprising a plurality of primary circuits 4 and secondary circuits 5.In the latter case, the method according to the invention applies mutatis mutandis, separately, to each pair of a primary circulation circuit 4 and a secondary circulation circuit 5 operating together and configured to implement a heat exchange by means of the secondary heat exchanger 7 which they comprise and at least one control means 6 or a plurality of control means 6.

[0070] Figures 9 and 10 illustrate examples of flowcharts separating the processing of information relating to the at least one primary circuit 4 and to the at least one secondary circuit 5 and the actions linked to such information. [Fig.9] illustrates a part of the method implemented in relation to the at least one primary circuit 4 while [Fig. 10] illustrates a part of the method implemented in relation to the at least one secondary circuit 5. Such a separation is simply made for the sake of clarity. It is nevertheless understood that the method according to the invention considers the entire thermal management system, namely each of the circuits that it comprises, simultaneously or successively.

[0071] Generally, the method according to the invention comprises a step E01 of measuring a temperature T_FAS of the supercharging air flow FAS and a temperature T_FR of the heat transfer fluid FR by means of the at least one primary temperature sensor 46 and the at least one secondary temperature sensor 55 respectively. Such measurements can be carried out at regular time intervals or in real time. In particular, as described previously, the temperature T_FAS of the supercharging air flow FAS is measured at the intake manifold of the powertrain 3 or at the inlet thereof. In particular, as described previously, the temperature T_FR of the heat transfer fluid FR is measured at the inlet of the cylinder head 31 of the powertrain 3.

[0072] The method then comprises a step E02 of determining a thermal management mode to be applied as a function of the measured temperatures. Here, the term "thermal management mode" means both a type of thermal treatment, such as a cooling requirement or not, and a level or intensity of such thermal treatment. For example, such a determination can be carried out by comparing the temperature measurement data relating to the supercharging air flow FAS with at least one predefined primary temperature threshold S_FAS and / or by comparing the temperature measurement data relating to the heat transfer fluid FR with at least one secondary temperature threshold S_FR. Such threshold values ​​can be stored on one or more memory elements of the vehicle 1 while the comparisons can be carried out by a processing unit comprising a calculator or an on-board computer.

[0073] The method then comprises a step E03 of applying the thermal management mode determined by adjusting a degree of opening of the at least one primary set of shutters 43 and / or of the at least one secondary set of shutters 52 by means of the control means 6. As explained previously, the at least one primary set of shutters 43 and the at least one secondary set of shutters 52 can each be arranged in an “open”, “closed” configuration or in an intermediate configuration, independently of one another.

[0074] In particular, the at least one primary set of flaps 43 is moved into its “open” configuration when the temperature T_FAS of the supercharging air flow FAS is greater than or equal to a first primary temperature threshold. S_FAS1, as indicated by mode E031a. For example, the first primary temperature threshold S_FAS1 is of the order of 150°C.

[0075] In this way, when a heating of the supercharging air flow FAS to a temperature greater than or equal to the first primary temperature threshold S_FAS1 is detected, that is to say when the cooling carried out at the secondary heat exchanger 7 is not sufficient, an additional cooling of the supercharging air flow FAS is implemented at the at least one primary heat exchanger 44, as described previously, so that the supercharging air flow FAS transfers calories to the outside air flow FE circulating through the at least one primary heat exchanger 44 and the at least one primary set of flaps 43, open.

[0076] Conversely, when no heating of the air flow is observed, that is to say the temperature T_FAS of the supercharging air flow FAS is strictly lower than the first primary temperature threshold S_FAS1, the at least one primary set of flaps 43 is arranged in a “closed” configuration since it is not necessary to implement heat exchange, as represented in [Fig.7] by the mode E030a. In this way, the aerodynamics of the vehicle 1 is optimized and the internal drag is reduced when the thermal treatment of the supercharging air flow FAS is not necessary.

[0077] Additionally or alternatively, the at least one secondary set of flaps 52 is moved into its “open” configuration, represented in [Fig. 10] by the mode E032a, when the temperature T_FR of the heat transfer fluid FR is greater than or equal to a first secondary temperature threshold S_FR1. For example, the first secondary temperature threshold S_FR1 is of the order of 90°C.

[0078] Thus, when a heating of the heat transfer fluid FR to a temperature greater than or equal to the first secondary temperature threshold S_FR1 is detected, a cooling of said fluid is implemented at the level of the at least one heat exchanger 53, as described previously, so that the heat transfer fluid FR gives up calories to the flow of outside air FE circulating through the at least one heat exchanger 53 and the at least one secondary set of flaps 52, open.

[0079] Conversely, when no heating of said fluid is observed, that is to say when the temperature T_FR of the heat transfer fluid FR is strictly lower than the first secondary temperature threshold S_FR1, the at least one secondary set of flaps 52 is arranged in the “closed” configuration, represented by the mode E030b, since it is not necessary to implement heat exchange.

[0080] Optionally again, the application step E03 of the thermal management mode may comprise the adjustment of an operating mode of the primary motor-fan unit 45 of the at least one primary cooling module 42. when the temperature T_FAS of the charge air flow FAS is greater than or equal to a second primary temperature threshold S_FAS2, greater than the first primary temperature threshold S_FAS1, represented by the mode E031b. For example, the second primary temperature threshold S_FAS2 is strictly greater than 150°C and less than or equal to 170°C, in particular it is of the order of 160°C.

[0081] Thus, for example, when the temperature T_FAS of the supercharging air flow FAS is greater than or equal to the first primary temperature threshold S_FAS1 and strictly less than the second primary threshold, the primary set of flaps 43 is placed in the “open” configuration while the motor-fan unit can be switched off, here forming the mode E031a. When the temperature T_FAS of the supercharging air flow FAS is greater than or equal to the second primary temperature threshold S_FAS2, the control means 6 can activate the primary motor-fan unit 45, then forming the mode E031b. Such a principle advantageously makes it possible to optimize the heat exchange implemented at the level of the primary heat exchanger 44.Optionally, the primary motor-fan unit 45 can be controlled so as to implement an outside air flow FE passing through the at least one primary heat exchanger 44 which is more or less significant depending on the measured temperature above the second primary temperature threshold S_FAS2 and / or depending on a longitudinal speed of the vehicle 1.

[0082] A similar principle applies mutatis mutandis for the secondary motor-fan unit 54, the method according to the invention then comprising the adjustment of an operating mode of said motor-fan unit when the temperature T_FR of the heat transfer fluid FR is greater than or equal to a second secondary temperature threshold S_FR2, greater than the first secondary temperature threshold S_FR1, here represented by the mode E032b. In this way, when the temperature T_FR of the heat transfer fluid FR is greater than or equal to the first secondary temperature threshold S_FR1 and strictly less than the second secondary temperature threshold S_FR2, the primary set of flaps 43 is placed in the “open” configuration and the motor-fan unit is switched off. Conversely, when the temperature T_FR of the heat transfer fluid FR is greater than or equal to the second secondary temperature threshold S_FR2.For example, the second secondary temperature threshold S_FR2 is of the order of 105°C.

[0083] Optionally, the application step E03 of the thermal management mode may comprise the limitation E031c of the torque of the powertrain 3 when the temperature T_FAS of the measured supercharging air flow FAS is greater than or equal to a third primary temperature threshold S_FAS3, strictly greater than the first primary temperature threshold S_FAS1 and the second primary temperature threshold S_FAS2. For example, the third primary temperature threshold S_FAS3 temperature is around 200°C.

[0084] In particular, in the case of a need to cool the supercharging air flow FAS, in particular when the temperature T_FAS of the measured supercharging air flow FAS is greater than or equal to the third primary temperature threshold S_FAS3, but it is detected that no need to cool the heat transfer fluid is required because the temperature of said fluid T_FR is strictly lower than the first secondary temperature threshold S_FR1, the method can be configured so as to implement the limitation E031c of the torque of the powertrain 3. Such a principle is in particular observed on a high torque demand in cold conditions. Such a torque limitation is implemented for the sake of reactivity of the at least one primary supercharging circuit 4, faster than the rise in temperature of the powertrain 3.

[0085] The present invention thus advantageously proposes a system and a method for thermal management of a hydrogen-powered vehicle ensuring optimized thermal regulation on two stages making it possible to limit the space requirement generated on the front face relative to systems of the prior art and making it possible to reduce the aerodynamic impact of said system on the performance of the vehicle. The thermal management system according to the invention also advantageously makes it possible, by virtue of its architecture on two stages of thermal treatment and the specific installation of sets of controlled flaps, to modulate the use of the different heat exchangers or heat exchangers according to the engine load cases so as to optimize the distribution of power within the vehicle and thus maintain a better energy balance.The present invention thus advantageously allows the implementation of different strategies for controlling said shutters, and consequently the thermal management system, making it possible to meet the varied needs of the vehicle.

[0086] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means or configuration and to any technically operative combination of such means insofar as they ultimately fulfill the functionalities described and illustrated in the present document.

Claims

Claims

1. Thermal management system (2) of a motor vehicle (1) equipped with a hydrogen powertrain (3), the thermal management system (2) comprising: - at least one primary supercharging circuit (4) capable of allowing the circulation of a supercharging air flow (FAS), said circuit comprising a turbocharger (41), a primary cooling module (42) comprising a primary set of controlled flaps (43) and a primary heat exchanger (44) configured to implement a heat exchange between the supercharging air flow (FAS) and an air flow (FE) outside the vehicle (1);- at least one secondary circuit (5) for circulating a heat transfer fluid (FR) comprising a hydrogen powertrain (3) and a secondary cooling module (51) comprising a secondary set of controlled flaps (52) and a heat exchanger (53) configured to implement a heat exchange between the heat transfer fluid (FR) and the air flow (FE) outside the vehicle (1); the system further comprising a means (6) for controlling the primary set of flaps (43) and the secondary set of flaps (52) and at least one secondary heat exchanger (7) configured to implement a heat exchange between the supercharging air flow (FAS) circulating in the at least one primary circuit (4) and the heat transfer fluid (FR) circulating in the at least one secondary circuit (5).;

2. Thermal management system (2) according to the preceding claim, wherein the at least one secondary heat exchanger (7): - is arranged downstream of the turbocharger (41) and upstream of the primary heat exchanger (44) in a direction of circulation of the supercharging air flow (FAS); and - is arranged downstream of the powertrain (3) and upstream of the at least one heat exchanger (53) in a direction of circulation of the heat transfer fluid (FR).

3. Thermal management system (2) according to one of the preceding claims, in which the at least one primary cooling module (42) is at least partly arranged upstream of the at least one secondary cooling module (51) in a direction of circulation of the outside air flow (FE), the primary set of flaps (43) being arranged so as to regulate the circulation of at least part of the outside air flow (FE) intended to circulate successively through the primary heat exchanger (44) then the heat exchanger (53).

4. Thermal management system (2) according to one of the preceding claims, comprising: - a plurality of primary supercharging circuits (4, 4a, 4b), each being capable of allowing the circulation of a supercharging air flow (FAS, FAS1, FAS2) specific to it and each of said circuits comprising a turbocharger (41, 41a, 41b), a primary cooling module (42, 42a, 42b) comprising a primary set of flaps (43, 43a, 43b) and a primary heat exchanger (44, 44a, 44b) configured to implement a heat exchange between the supercharging air flow (FAS, FAS1, FAS2) specific to said circuit and an air flow (FE) outside the vehicle (1);- a plurality of secondary circuits (5, 5a, 5b) for circulating a heat transfer fluid (FR), each comprising at least a part of the powertrain (3) and a secondary cooling module (51, 51a, 51b) comprising a secondary set of flaps (52, 52a, 52b) and a heat exchanger (53, 53a, 53b) configured to implement a heat exchange between the heat transfer fluid (FR) and the air flow (FE) outside the vehicle (1); the system further comprising a plurality of secondary heat exchangers (7, 7a, 7b), each being configured to implement a heat exchange between the charge air flow (FAS, FAS1, FAS2) circulating in one of the primary circuits (4, 4a, 4b) and the heat transfer fluid (FR) circulating in one of the secondary circuits (5, 5a, 5b).;

5. Thermal management system (2) according to the preceding claim, comprising at least one pump (32) arranged so as to be common to the plurality of secondary circuits (5, 5a, 5b) for circulating a heat transfer fluid (FR).

6. Motor vehicle (1) comprising a thermal management system (2) according to one of the preceding claims.

7. Thermal management method (100) of a motor vehicle (1) according to the preceding claim, the vehicle (1) being equipped with at least one primary temperature sensor (46), capable of measuring a temperature (T_FAS) of the supercharging air flow (FAS) at at least one point of the at least one primary circuit (4), and a secondary temperature sensor (55) configured to measure a temperature (T_FR) of the fluid ca- carrier (FR) at at least one point of the at least one secondary circuit (5), the method comprising: - a step of measuring (E01) a temperature (T_FAS) of the supercharging air flow (FAS) and of the heat transfer fluid (FR) via the primary temperature sensor (46) and the secondary temperature sensor (55) respectively; - a step of determining (E02) a thermal management mode to be applied as a function of the measured temperatures;- a step of applying (E03) the thermal management mode determined by adjusting a degree of opening of at least the primary set of flaps (43) and / or the secondary set of flaps (52) by means of the control means (6), the primary set of flaps (43) being open when the temperature (T_FAS) of the supercharging air flow (FAS) is greater than or equal to a first primary temperature threshold (S_FAS1) and / or the secondary set of flaps (52) being open when the temperature (T_FR) of the heat transfer fluid (FR) is greater than or equal to a first secondary temperature threshold (S_FR1).;

8. Thermal management method (100) according to the preceding claim, wherein the at least one primary cooling module (42) comprises a primary motor-fan unit (45) and the at least one secondary cooling module (51) comprises a secondary motor-fan unit (54), the step of applying (E03) the thermal management mode comprising adjusting an operating mode of the primary motor-fan unit (45) when the temperature (T_FAS) of the charge air flow (FAS) is greater than or equal to a second primary temperature threshold (S_FAS2), greater than the first primary temperature threshold (S_FAS1), and / or adjusting an operating mode of the secondary motor-fan unit (54) when the temperature (T_FR) of the heat transfer fluid (FR) is greater than or equal to a second secondary temperature threshold (S_FR2), greater than the first secondary temperature threshold (S_FR1).

9. Thermal management method (100) of a motor vehicle (1) according to the preceding claim, in which the step E03 of applying the thermal management mode comprises limiting the torque of the powertrain (3) when the temperature (T_FAS) of the supercharging air flow (FAS) is greater than or equal to a third primary temperature threshold (S_FAS3).

10. A computer program product comprising program code instructions recorded on a computer-readable medium for implementing the steps of the thermal management method (100) according to any one of claims 7 to 9 when said program is running on a computer.

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