HYBRID MOTOR VEHICLE COMPRISING AN INTERNAL COMBUSTION ENGINE WITH TEMPERATURE CONTROLLED BY A THERMOSTAT UNIT AND A THERMO-HYDRAULIC COOLING SYSTEM

Abstract

The invention relates to a hybrid motor vehicle, comprising a heat transfer fluid circuit including, from a thermal engine (90) to an engine pump (150) and a radiator circuit (58), a thermostat housing (100) with a first branch (91) including a thermostat (110) supplying the radiator circuit (58), a second branch (92) split into a third branch (93) including an additional pump (30) and a heat transfer fluid heater (20) and supplying an air heater (32) then an engine heat exchanger (160), and a fourth branch (94) including a bypass (140) supplying the engine heat exchanger (160) in the open position, and a fifth branch (95) between the air heater (32) and the third branch (93) upstream of the additional electric pump (30), including a non-return valve (130) arranged to prohibit any direct flow between the third branch (93) and the engine heat exchanger (160). Figure 5

Description

Title of the invention: HYBRID MOTOR VEHICLE COMPRISING A HEAT ENGINE REGULATED IN TEMPERATURE BY A THERMOSTAT BOX AND A THERMO-HYDRAULIC MANAGEMENT OF THE COOLING CIRCUIT

[0001] The invention relates to a hybrid motor vehicle, comprising a heat engine temperature-regulated by a heat transfer fluid circuit comprising a radiator circuit, an engine pump, the heat transfer fluid circuit comprising, from said heat engine to said engine pump, a thermostat housing with a first branch comprising a thermostat of the radiator circuit and supplying said radiator circuit via an inlet branch, and a second branch supplying an air heater, an outlet channel of which supplies an inlet channel which comprises an engine exchanger, the outlet of which joins, upstream of said engine pump, an outlet branch from said radiator circuit.

[0002] A hybrid vehicle (or HEV) has an internal combustion engine, and a large battery and a powerful electric motor, to travel short distances at low speed using only the electric motor. A plug-in hybrid vehicle (or PHEV) is a hybrid electric vehicle whose traction battery is designed to be charged by connection to an external energy source.

[0003] A MHEV (“mild-hybrid”) vehicle has a low-voltage battery of limited capacity; the electric motor assists the thermal engine, but cannot provide the drive alone.

[0004] A PHEV (Plug-in Hybrid Electric Vehicle) is a rechargeable hybrid vehicle, with a battery (generally lithium-ion) allowing it to drive in all-electric mode, and whose two engines, thermal and electric, are capable of driving the running gear.

[0005] Cooling the heat engine, the electric motor, and the battery pack represents a significant amount of energy, as does heating the passenger compartment. A cooling circuit on the heat engine carries a heat transfer fluid through a radiator, with the assistance of a circulation pump; it is generally used for heating the passenger compartment by means of an air heater. The heating circuit is completed by a high-voltage electric fluid heater called HVWH (High Voltage Water Heater).

[0006] Various architectural solutions are known for separating the air heater branch from the heat engine circuit. A first solution includes a solenoid valve.

[0007] A second solution, described in document FR3078386B1, comprises a thermostatic housing (4-way valve for example), remote from the engine outlet, comprising a thermostat opening at a temperature of 60°C to 70°C, below the opening temperature of the main thermostat located in the engine water outlet housing.This thermal system of a hybrid or electric vehicle comprises a first very low temperature loop comprising a traction battery supplying an electric traction machine and an air conditioning cooler of the vehicle, a second high temperature loop comprising an electric fluid heater and a heater for heating the passenger compartment, and a third low temperature loop comprising the electric traction machine, its control inverter and a heat exchanger with the ambient air, this system comprising a first controlled valve with at least three ways capable of isolating or putting in series the very low temperature circuit and the high temperature circuit, and a second controlled valve with at least three ways capable of isolating or putting in series the high temperature circuit and the low temperature circuit.This architecture is well suited to managing cooling and heating flows in such a hybrid electric vehicle, however the design of the water outlet housing is relatively complex and expensive.

[0008] The present invention proposes to develop a new family of circuit architecture which connects the engine circuit to the air heater circuit, or which separates the engine circuit from the air heater circuit, using an engine water outlet box which integrates the functionality of such a thermostatic box (or 4-way valve solution) presented in document FR3078386B1.

[0009] The objective of the present invention is to overcome these drawbacks by proposing to adapt the heat transfer circuit of a conventional thermal engine into a heat transfer circuit meeting the needs of passenger compartment thermal performance and fuel consumption savings for electrified powertrains known as CTE (HEV, MHEV, PHEV), by transforming the water outlet housing in a modular and low-cost manner, by transforming a heat transfer circuit of a conventional engine into a heat transfer circuit of a CTE electrified powertrain, by integrating a simple thermostat in the engine water outlet housing, as well as a non-return valve in the air heater branch. A CTE electrified powertrain is a high energy efficiency powertrain, optimized as regards the architecture of the powertrain, the energy management strategy, and the definition of the electrical power components.The optimization is based on the comparison of different hybrid electric powertrain architectures based on the minimum energy consumption achievable by each of them on automotive cycles.

[0010] To achieve this objective, the invention proposes a hybrid motor vehicle, comprising a heat engine temperature-regulated by a heat transfer fluid circuit comprising a radiator circuit, an engine pump, the heat transfer fluid circuit comprising, from said heat engine to said engine pump, a thermostat housing with a first branch comprising a thermostat of the radiator circuit and supplying said radiator circuit via an inlet branch, and a second branch supplying an air heater, an outlet channel of which supplies an inlet channel which comprises an engine exchanger, the outlet of which joins, upstream of said engine pump, an outlet branch from said radiator circuit.

[0011] According to the invention, said second branch separates, upstream of said air heater, into a third branch supplying said air heater and into a fourth branch comprising a bypass and arranged to supply said engine exchanger in the open position of said bypass, said third branch comprising, upstream of said air heater, an additional electric pump and a heat transfer fluid heater, said thermostat housing further comprising, on a fifth branch between said outlet channel of said air heater and said third branch upstream of said additional electric pump, a non-return valve arranged to prevent any direct flow between said third branch and said engine exchanger.

[0012] Thanks to the invention, this functional architecture of a heat transfer circuit of a hybrid vehicle allows thermo-hydraulic management of the air heater branch by a heat transfer fluid outlet thermostat housing integrating passive thermo-hydraulic actuation components.

[0013] In a first variant, said third branch comprises an air heater circuit thermostat upstream of the additional electric pump and upstream of the junction with said fifth branch and said non-return valve.

[0014] This arrangement is favorable for a vehicle operating in a temperate or cold climate.

[0015] Advantageously, said motor vehicle comprises control means associated with said radiator circuit thermostat and / or at least one temperature sensor of said heat transfer fluid in said heat engine, and which are arranged to control the opening or closing of the bypass, and to control the operation or stopping of said engine pump, said additional electric pump, said air heater, and said heat transfer fluid heater.

[0016] It is thus possible to quickly select the optimal heat transfer fluid circuit for cooling or heating the thermal engine or the passenger compartment.

[0017] Advantageously, said control means, when observing a temperature of the heat transfer fluid in said heat engine lower than a first temperature predetermined, are arranged to establish a circulation of said heat transfer fluid in a short loop in said third branch and said fifth branch, by actuating said additional electric pump, said air heater, and said heat transfer fluid heater, while avoiding said heat engine.

[0018] This facilitates the rise in temperature of the heat transfer fluid. Cold starting of the vehicle is also optimal.

[0019] In a second variant, the only thermostat included in said thermostat housing is said radiator circuit thermostat, and said control means are arranged to control said bypass to allow the passage of a portion of said heat transfer fluid into said fourth branch and passing through said heat engine.

[0020] This arrangement is favorable for a vehicle operating in a hot or tropical climate.

[0021] Advantageously, said control means, when a temperature of the heat transfer fluid in said heat engine is observed to be higher than a second predetermined temperature, are arranged to establish a circulation of said heat transfer fluid in a long loop in said third branch and said fourth branch, passing through said air heater and said heat transfer fluid heater, and passing through said heat engine.

[0022] It is thus possible to limit the vehicle's energy consumption to what is strictly necessary.

[0023] Advantageously, said second predetermined temperature is higher than said first predetermined temperature.

[0024] With a difference of at least 10°C between these two temperatures, the regulation is well differentiated.

[0025] Advantageously, said control means are arranged to, during circulation of said heat transfer fluid in a long loop, actuate said additional electric pump.

[0026] It is thus possible to temporarily increase the flow rate of the heat transfer fluid; this additional pump can be switched off when the flow rate of the fluid in the air heater is sufficient.

[0027] In the second variant, the only thermostat that said thermostat housing comprises is said radiator circuit thermostat, and said control means are arranged to control said bypass to allow the passage of a portion of said heat transfer fluid into said fourth branch and passing through said heat engine, and are further arranged to deactivate said heat transfer fluid heater.

[0028] This arrangement allows a small leakage rate of the heat transfer fluid to be allowed towards the thermal engine, to the temporary detriment of heating the vehicle's passenger compartment via the air heater.

[0029] Advantageously, said heat transfer fluid heater is a high voltage electric heater.

[0030] This arrangement makes it possible to quickly obtain significant power.

[0031] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates a conventional heat transfer circuit, according to the prior art, of a conventional heat engine temperature-regulated by a radiator circuit, the heat transfer fluid being driven by a motor pump, the heat transfer fluid circuit comprising, from the heat engine to the motor pump, a thermostat housing with a first branch comprising a radiator circuit thermostat and leading to the radiator circuit, and a second branch passing through an air heater then an engine exchanger, before joining a flow of heat transfer fluid from the radiator circuit, then the engine pump; - [Fig.2] schematically illustrates the adaptation according to the invention to the needs of a HEV / PHEV hybrid electric vehicle of the classic heat transfer circuit of a conventional thermal engine according to [Fig.l], with the addition in a third branch, between the thermostat housing and the air heater, of an additional electric pump and a high voltage electric fluid heater, called HVWH, and with the incorporation in the thermostat housing of a by-pass on a fourth branch, and of a non-return valve on a fifth branch, in a first variant in which the thermostat housing also comprises an air heater circuit thermostat on the third branch upstream of the additional electric pump; - [Fig.3] schematically illustrates, in a strong line, a circulation of heat transfer fluid in a closed loop, in the third branch of the heat transfer circuit of [Fig.2], through the additional electric pump, the electric heater of the high voltage fluid HVWH, the air heater, and, in the fifth branch, through the non-return valve; this circulation does not pass through the heat engine whose cooling circuit is in a broken line; - [Fig.4] schematically illustrates, in strong lines, a circulation of fluid ca long loop carrier, in the heat transfer circuit of [Fig.2], in the third branch, through the air heater circuit thermostat, the additional electric pump, the high voltage electric fluid heater HVWH, from the heater, and through the engine exchanger and the engine pump; this circulation passes through the heat engine whose radiator circuit is in a broken line; - [Fig.5] schematically illustrates a second variant of the heat transfer circuit, where the only thermostat included in the thermostat housing is the radiator circuit thermostat, the thermostat housing then being without the air heater circuit thermostat of the first variant shown in [Fig.2] - [Fig.6] schematically illustrates, in strong lines, a circulation of fluid ca short loop carrier, in the heat transfer circuit of [Fig.5], through, on the one hand in the third branch of the additional electric pump, the electric heater of the high voltage fluid HVWH, the air heater, and in the fifth branch of the non-return valve passing, and on the other hand in the fourth branch of the bypass passing, towards the engine exchanger; this circulation includes a very reduced passage through the heat engine, in broken line; - [Fig.7] schematically illustrates, in strong lines, a circulation of fluid ca long loop carrier, in the heat transfer circuit of [Fig.5], through, on the one hand in the third branch of the additional electric pump, the electric heater of the high voltage fluid HVWH, the air heater, and on the other hand in the fourth branch of the bypass passing, towards the engine exchanger and the engine pump; this circulation passes through the heat engine whose radiator circuit is in broken line; - [Fig.8] schematically illustrates a hybrid motor vehicle, comprising a heat engine cooled by a radiator loop and an electric traction machine temperature-regulated by a thermal system according to the invention comprising several heat transfer fluid loops.

[0032] The invention relates more particularly to the functional architecture of a heat transfer circuit of a Plug In Hybrid vehicle (PHEV) 1000.

[0033] The thermo-hydraulic management of the aerothermal branch is carried out by a fluid outlet thermostat housing 100 integrating passive thermo-hydraulic actuation components.

[0034] The invention relates more particularly to the architecture of the heat transfer circuit of a Plug-In Hybrid Vehicle (PHEV), making it possible to cool a thermal engine 90 and an electric motor (not shown in the figures) integrated within an electrified automatic gearbox, using an air / heat transfer fluid exchanger (radiator), by means of a liquid heat transfer fluid (in particular a water / glycol mixture). This same circuit makes it possible to supply calories to the vehicle passenger compartment for the comfort of its occupants using an air heater 32 and a fluid heater 20, in particular and not limited to a high voltage HVWH electric fluid heater, or even a heat store.

[0035] The invention relates to a hydraulic device for heating the passenger compartment cabin, in all-electric operating mode, with the least energy loss, by separating the air heater branch, composed of the fluid heater 20 and the air heater 32, from the engine circuit.

[0036] As explained above, the invention adapts the heat transfer circuit of a conventional thermal engine into a heat transfer circuit meeting the needs of passenger compartment thermal performance and fuel consumption savings for CTE electrified powertrains, by transforming the water outlet housing in a modular and low-cost manner, by transforming a heat transfer circuit of a conventional engine into a heat transfer circuit of a CTE electrified powertrain, and by integrating a simple thermostat in the engine water outlet housing, as well as a non-return valve in the air heater branch.

[0037] From a classic heat transfer circuit of a conventional thermal engine, as visible in [Fig.l], consisting of an air heater 32 (“cabin heater” in English), a radiator 58 (“radiator” in English), the invention proposes a heat transfer circuit architecture meeting the needs of a hybrid vehicle 1000 thermal engine / electric motor in the manner shown in [Fig.2].

[0038] In order to satisfy the passenger compartment thermal comfort in all-electric propulsion mode or in hybrid thermal engine / electric motor propulsion under conditions explained below, there is arranged in the air heater branch of the heat transfer circuit a thermostat within the water outlet housing, and a fluid heater 20, in particular a high voltage electric fluid heater called HVWH (from the English "High Voltage Water Heater" or high voltage water heater), in particular an electrical resistor.

[0039] Depending on the established propulsion mode (100% electric, 100% thermal engine, hybrid thermal engine / electric), passive hydraulic actuators (such as non-return valve 130) or active hydraulic actuators (such as water pump 30, controlled thermostat 120) are used to evacuate the calories to the appropriate components following a desired water circulation within the heat transfer circuit.

[0040] The passenger compartment thermal performance and the cold engine starting performance are detailed below.

[0041] In order to satisfy the thermal comfort of the vehicle occupants, the circulation of water within the air heater branch is established according to the internal water temperature of the heat engine.

[0042] For an internal water temperature of the thermal engine lower than a first threshold temperature Tl (approximately 60°C or 70°C), a circulation of water, called a "short loop", as visible in [Fig.3], is established, by actuation of an additional electric water pump 30, between the air heater 32, the heater 20, in particular the high voltage electric fluid heater HVWH, or even a heater operating on fuel or an enthalpy storer or an exhaust heat recovery device, without passing through the heat engine 90, regardless of the activation of the heat engine.

[0043] The advantages of this configuration compared to a conventional heat transfer circuit architecture (where the heat engine 90 is directly linked to the air heater 32) are as follows: rapid rise in water temperature, improved cold start.

[0044] The volume of coolant within this "short loop" being restricted (of the order of a liter), the rise in water temperature caused by the fluid heater 20, and, optionally by an additional heat device (heat storer, RTE or similar), is much faster than if it was necessary to heat the volume of the complete heat transfer circuit which is much larger (approximately 5 liters to 8 liters of water volume including the engine circuit).As a result, the rise in passenger compartment air temperature is accelerated, and the amount of energy used to heat this circuit, and consequently the passenger compartment of the vehicle, is much lower than in the prior art, which improves the autonomy in electric mode of the hybrid vehicle: in particular, the fluid heater 20, in particular high voltage electric HVWH, as well as optionally the heating devices, requires a lower thermal power to regulate the temperature of the coolant to an acceptable threshold at the air heater inlet to maintain suitable passenger compartment comfort.

[0045] As for the engine starting performance, when cold, it is improved for very cold ambient temperatures. Indeed, thanks to the separation of the engine and heater circuits, the engine water temperature sensor installed within the engine water outlet housing, which must be representative of the temperature of the engine combustion chamber, is not disturbed by the volume of coolant heated by the HVWH, or even optionally by an additional heating device. Otherwise and in the prior art, the erroneous information on the temperature of the liquid can lead to engine stalling during starting, especially for cold ambient temperature conditions.

[0046] For a water temperature inside the heat engine higher than a second threshold temperature T2 (approximately 80°C), a water circulation, called a "long loop", as visible in [Fig.4], is established between the air heater 32, the fluid heater 20, or even an additional heat device, and the heat engine 90. In this configuration, the temperature of the coolant supplying the air heater branch from the heat engine is such that it is no longer useful to use the fluid heater or the additional heat device. In addition, for certain engine operating speeds, the water flow rate within the air heater, provided by the heat engine water pump, is sufficient, when the additional electric water pump in the branch is deactivated, thus reducing the energy consumption of the cooling system while guaranteeing sufficient flow in the air heater, ensuring the passenger compartment thermal performance.

[0047] For exclusive use in very hot countries where the performance of the passenger compartment heating service is less important, the thermostat housing can be simplified, by removing the air heater thermostat, according to the configuration visible in [Fig.5].

[0048] The circulation in the outlet housing is managed on the basis of a dimensioning carried out as precisely as possible. It is permissible to degrade the passenger compartment heating performance, by allowing a small leakage flow rate to pass through the engine, as small as possible for a water temperature inside the heat engine lower than a first threshold temperature T1 (approximately 60°C or 70°C), during the circulation of water, called in a "short loop" between the air heater 32, the fluid heater 20, HVWH, or even a heater operating on fuel or an enthalpy storer or an exhaust heat recovery device. The bypass 140 inside the thermostat housing 100 is hydraulically dimensioned so as to limit the leakage flow rate inside the engine, as visible in [Fig.6].

[0049] For a water temperature inside the heat engine higher than a second threshold temperature T2 (approximately 80°C), a water circulation, called a "long loop", is established between the air heater 32, the electric heater 20 of the high-voltage fluid HVWH, or even an additional heating device, and the heat engine 90. The bypass 140 inside the thermostat housing 100 is hydraulically dimensioned so as to have enough heat flow within the air heater, the electric heater of the high-voltage fluid HVWH being switched off, as seen in [Fig.7].

[0050] Naturally, this motor vehicle 1000 comprises an electric traction machine, and a battery pack, the temperature regulation of which can advantageously be carried out by at least one of the heat transfer fluid loops of the thermal system comprising a heat transfer fluid circuit according to the invention.

[0051] More particularly, as illustrated by the figures in an advantageous but non-limiting configuration, the hybrid motor vehicle 1000 comprises a thermal engine 90 regulated in temperature by a heat transfer fluid circuit comprising a radiator circuit 58, a motor pump 150.

[0052] The heat transfer fluid circuit comprises, from the heat engine 90 to the motor pump 150, a thermostat housing 100 with a first branch 91 comprising a thermostat of the radiator circuit 110 and supplying the radiator circuit 58 via an inlet branch 57, and a second branch 92 supplying an air heater 32, an outlet channel 96 of which supplies an inlet channel 99 which comprises an engine exchanger 160, the outlet of which joins, upstream of the motor pump 150, an outlet branch 59 from the radiator circuit 58.

[0053] In a manner specific to the invention, the second branch 92 separates, upstream of the air heater 32, into a third branch 93 supplying the air heater 32 and into a fourth branch 94 comprising a bypass 140 and arranged to supply the engine exchanger 160 in the open position of the bypass 140.

[0054] This third branch 93 comprises, upstream of the air heater 32, an additional electric pump 30 and a heat transfer fluid heater 20.

[0055] The thermostat housing 100 also comprises, on a fifth branch 95 between the outlet channel 96 of the air heater 32 and the third branch 93 upstream of the additional electric pump 30, a non-return valve 130 which is arranged to prevent any direct flow between the third branch 93 and the engine exchanger 160.

[0056] More particularly, the third branch 93 comprises an air-heating circuit thermostat 120 upstream of the additional electric pump 30 and upstream of the junction with the fifth branch 95 and the non-return valve 130.

[0057] More particularly, the motor vehicle 1000 comprises control means 200 which are associated with the thermostat of the radiator circuit 110 and / or at least one temperature sensor of the heat transfer fluid in the thermal engine 90, and which are arranged to control the opening or closing of the bypass 140, and to control the operation or stopping of the engine pump 150, of the additional electric pump 30, of the air heater 32, and of the heat transfer fluid heater 20.

[0058] More particularly, the control means 200, when a temperature of the heat transfer fluid in the heat engine 90 is observed to be lower than a first predetermined temperature T1, are arranged to establish a circulation of the heat transfer fluid in a short loop in the third branch 93 and the fifth branch 95, by actuating the additional electric pump 30, the air heater 32, and the heat transfer fluid heater 20, while avoiding the heat engine 90.

[0059] More particularly, in the second variant illustrated from [Fig.5] to [Fig.7], the only thermostat that the thermostat housing 100 comprises is the thermostat of the radiator circuit 110, and the control means 200 are arranged to control the bypass 140 to authorize the passage of a portion of the heat transfer fluid in the fourth branch 94 and passing through the heat engine 90. More particularly, the control means 200 are further arranged to deactivate the heat transfer fluid heater loporteur 20.

[0060] More particularly, the control means 200, when a temperature of the heat transfer fluid in the heat engine 90 is observed to be higher than a second predetermined temperature T2, are arranged to establish a circulation of the heat transfer fluid in a long loop in the third branch 93 and the fourth branch 94, passing through the air heater 32 and the heat transfer fluid heater 20, and passing through the heat engine 90.

[0061] More particularly, the second predetermined temperature T2 is higher than the first predetermined temperature T1.

[0062] More particularly, the control means 200 are arranged to, during circulation of the heat transfer fluid in a long loop, actuate the additional electric pump 30.

[0063] More particularly, the heat transfer fluid heater 20 is a high voltage electric heater.

[0064] In short, the invention makes it possible to have a compact and inexpensive solution compared to a solution for which components would be developed separately (the water outlet housing, the air heater thermostat, and the non-return valve).

[0065] The invention provides significant advantages. The "4-way valve" functionality is now integrated into the engine thermostat housing, this configuration makes it possible to save space in the engine block, this space being very expensive for PHEV type powertrains. The cost can be significantly reduced, especially if the thermostat housing is supplied in a lower-cost PHEV version by removing the air heater thermostat, if the passenger compartment thermal performance is satisfactory in ZEV, particularly for hot countries.

Claims

Claims

1. Hybrid motor vehicle (1000), comprising a heat engine (90) temperature-regulated by a heat transfer fluid circuit comprising a radiator circuit (58), an engine pump (150), the heat transfer fluid circuit comprising, from said heat engine (90) to said engine pump (150), a thermostat housing (100) with a first branch (91) comprising a thermostat of the radiator circuit (110) and supplying said radiator circuit (58) via an inlet branch (57), and a second branch (92) supplying an air heater (32) whose outlet channel (96) supplies an inlet channel (99) which comprises an engine exchanger (160) whose outlet joins, upstream of said engine pump (150), an outlet branch (59) from said radiator circuit (58), characterized in that said second branch (92) separates, upstream of said air heater (32),in a third branch (93) supplying said air heater (32) and in a fourth branch (94) comprising a bypass (140) and arranged to supply said engine exchanger (160) in the open position of said bypass (140), said third branch (93) comprising, upstream of said air heater (32), an additional electric pump (30) and a heat transfer fluid heater (20), said thermostat housing (100) further comprising, on a fifth branch (95) between said outlet channel (96) of said air heater (32) and said third branch (93) upstream of said additional electric pump (30), a non-return valve (130) arranged to prevent any direct flow between said third branch (93) and said engine exchanger (160).,

2. Motor vehicle (1000) according to claim 1 characterized in that said third branch (93) comprises an air heater circuit thermostat (120) upstream of the additional electric pump (30) and upstream of the junction with said fifth branch (95) and said non-return valve (130).

3. Motor vehicle (1000) according to claim 1 or 2 characterized in that said motor vehicle (1000) comprises control means (200) associated with said radiator circuit thermostat (110) and / or at least one temperature sensor of said heat transfer fluid in said heat engine (90), and which are arranged to control the opening or closing of said bypass (140), and to control the operation or stopping of said engine pump (150), of said additional electric pump (30), said air heater (32), and said heat transfer fluid heater (20).

4. Motor vehicle (1000) according to claim 3 characterized in that said control means (200), when observing a temperature of the heat transfer fluid in said heat engine (90) lower than a first predetermined temperature, are arranged to establish a circulation of said heat transfer fluid in a short loop in said third branch (93) and said fifth branch (95), by actuating said additional electric pump (30), said air heater (32), and said heat transfer fluid heater (20), avoiding said heat engine (90).

5. Motor vehicle (1000) according to claim 4 characterized in that the only thermostat that said thermostat housing (100) comprises is said radiator circuit thermostat (110), and in that said control means (200) are arranged to control said bypass (140) to authorize the passage of a part of said heat transfer fluid into said fourth branch (94) and passing through said heat engine (90).

6. Motor vehicle (1000) according to one of claims 3 to 5, characterized in that said control means (200), when a temperature of the heat transfer fluid in said heat engine (90) is observed to be higher than a second predetermined temperature, are arranged to establish a circulation of said heat transfer fluid in a long loop in said third branch (93) and said fourth branch (94), passing through said air heater (32) and said heat transfer fluid heater (20), and passing through said heat engine (90).

7. Motor vehicle (1000) according to claims 4 and 6 characterized in that said second predetermined temperature is higher than said first predetermined temperature.

8. Motor vehicle (1000) according to claim 6 or 7 characterized in that said control means (200) are arranged to, during circulation of said heat transfer fluid in a long loop, actuate said additional electric pump (30).

9. Motor vehicle (1000) according to one of claims 6 to 8 characterized in that the only thermostat that said thermostat housing (100) comprises is said radiator circuit thermostat (110), and in that said control means (200) are arranged to control said bypass (140) to authorize the passage of a part of said ca- carrier in said fourth branch (94) and passing through said heat engine (90), and are further arranged to deactivate said heat transfer fluid heater (20).

10. A motor vehicle (1000) according to any one of the claims 1 to 9 characterized in that said heat transfer fluid heater (20) is a high voltage electric heater.

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