Thermal conditioning system

Abstract

The invention relates to a method (2) for controlling a thermal conditioning system (1) of a vehicle, said system comprising a refrigerant circuit (100) and a heat transfer fluid circuit (200), said refrigerant circuit (100) comprising: a main loop (A) comprising: -- a compression device (3), -- a first expansion member (6), -- a first heat exchanger (4) -- a second heat exchanger (5), - a secondary branch (B), comprising a two-fluid heat exchanger (7) arranged in the heat transfer fluid circuit (200), comprising an electric heating device (9) for heating said heat transfer fluid (LC), the method (2) comprising controlling the power of the electric heating device (9) so that a measured heat transfer fluid temperature (Tm) reaches a setpoint temperature (Thvch_sp) determined from input data. Figure from the summary: Figure 3

Description

Title of the invention: Thermal conditioning system technical field

[0001] The present invention relates to the field of thermal conditioning systems. Such systems can, for example, be fitted to motor vehicles. These systems ensure thermal regulation of various components, such as the passenger compartment or an electrical energy storage battery, when the vehicle is electrically powered. Heat exchange is managed primarily by the compression and expansion of a refrigerant circulating in a circuit containing several heat exchangers. A compressor forces the refrigerant to a high pressure and circulate it through the circuit. Previous technique

[0002] The refrigerant circuit typically comprises a main loop and several branch lines that allow for multiple refrigerant circulation combinations. Numerous operating modes can thus be achieved, for example, cooling the passenger compartment air, heating the passenger compartment air, dehumidifying the passenger compartment air, or cooling the vehicle's batteries. It is known to use an additional heating device to supplement the heat supplied by the refrigerant circuit in certain heating modes.

[0003] One drawback is that among the modes in which the additional heating device is used, it is not used in such a way as to minimize the overall consumption of the thermal conditioning system while ensuring the performance required of said system. Summary

[0004] To this end, one aspect of the present invention proposes a method for controlling a vehicle's thermal conditioning system, said system comprising a refrigerant circuit and a heat transfer fluid circuit, said refrigerant circuit comprising: - a main loop, said main loop comprising successively, according to the direction of circulation of the refrigerant: — a refrigerant compression device,

[0005] — a first heat exchanger arranged to be traversed by a flow of a fluid heat transfer fluid and intended to heat said heat transfer fluid,

[0006] — a first release mechanism,

[0007] — a second heat exchanger located between the first heat exchanger and the compression device, designed in particular to evaporate the refrigerant, by recovering heat extracted from an outside airflow, for example directly or indirectly,

[0008] the first expansion valve located between the first heat exchanger and the second heat exchanger, - a first secondary branch, connecting a first branch point to a first junction point, said first secondary branch comprising successively, according to the direction of circulation of the refrigerant, a second expansion device, a two-fluid heat exchanger arranged in the heat transfer fluid circuit and intended to evaporate the refrigerant, said first branch point being located between the first heat exchanger and the first expansion device, said first junction point being located between the second heat exchanger and the compression device, said heat transfer fluid circuit comprising an electric heating device for heating said heat transfer fluid,

[0009] said thermal conditioning system being configured to operate in "electric heating" mode, or in "electric heating and heat pump" mode: - said "electric heating" mode being a mode in which the electric heating device is active and serves as a heat source to heat the heat transfer fluid and evaporate the refrigerant in the two-fluid heat exchanger, the heat being returned by the first heat exchanger to the heat transfer fluid passing through it, thanks to the compression of the refrigerant within the compression device, the second heat exchanger being inactive, said "electric heating and heat pump" mode being a mode in which, on the one hand, the electric heating device is active and serves as a heat source to heat the heat transfer fluid and evaporate the refrigerant in the two-fluid heat exchanger, and in which, on the other hand, the outside air serves as a heat source to evaporate the refrigerant in the second heat exchanger, all the heat taken from the two-fluid heat exchanger and the second heat exchanger being returned by the first heat exchanger to the heat transfer fluid passing through it, thanks to the compression of the refrigerant within the compression device,

[0010] said method comprising, in the "electric heating" and "electric heating and heat pump" modes, a control of the power of the electric heating device so that a temperature of the heat transfer fluid measured in the circuit of The heat transfer fluid reaches a setpoint temperature, said setpoint temperature being determined from input data, said input data comprising representative quantities of: - a setpoint temperature for heating the heat transfer fluid at the outlet of the first heat exchanger, - of an outside temperature outside the vehicle, - of a flow rate of heat transfer fluid passing through the first heat exchanger, - of a refrigerant fluid pressure located downstream of the second heat exchanger and / or the two-fluid heat exchanger and upstream of the compression device, - of a flow rate of heat transfer fluid passing through the two-fluid heat exchanger, - the temperature of the heat transfer fluid passing through the first heat exchanger, upstream of the first heat exchanger, - of a compression power transmitted to the refrigerant by the compression device.

[0011] Thus this aspect of the invention makes it possible to limit the consumption of the electric heating device to the strict minimum while ensuring the heating performance required of the thermal conditioning system.

[0012] According to particular embodiments, the process may include one or several of the following characteristics, taken individually or in all technically possible combinations: - the measured heat transfer fluid temperature is the heat transfer fluid temperature at the outlet of the electric heating device; - Alternatively, the measured heat transfer fluid temperature is the heat transfer fluid temperature at the inlet of the two-fluid heat exchanger; - according to another embodiment, the measured heat transfer fluid temperature is a heat transfer fluid temperature at the outlet of the two-fluid heat exchanger; - the heat transfer fluid circuit includes a pump for circulating the heat transfer fluid in the heat transfer fluid circuit; - according to one embodiment, the heat transfer fluid circuit includes a third heat exchanger thermally coupled with an element of the traction chain; - the traction chain element includes, for example, an electrical energy storage battery; - Alternatively, the element of the vehicle's electric powertrain may include an electric vehicle traction motor; Alternatively, the vehicle's electric powertrain element may include an electronic control unit for the vehicle's electric traction motor; The third heat exchanger includes, for example, a wall of a casing of the element of the electric traction chain; The heat transfer fluid passing through the third heat exchanger is in contact with the casing wall. The heat released by the operation of the electric traction chain element passes through the casing wall and is transferred to the heat transfer fluid; The heat transfer circuit includes a means of bypassing the third heat exchanger; In the embodiment where the heat transfer fluid circuit includes the third heat exchanger, the heat transfer fluid circuit includes a bypass branch of the third heat exchanger, connecting a second divergence point located between the outlet of the two-fluid heat exchanger and the inlet of the third heat exchanger to a second junction point located between the outlet of the third heat exchanger and the inlet of the electric heating device; The bypass means is, for example, a three-way valve located at the second divergence point, and having a first outlet to the inlet of the third heat exchanger and a second outlet to the bypass branch; According to another embodiment, the bypass means includes two shut-off valves, a first shut-off valve located at the inlet of the third heat exchanger, and a second shut-off valve located on the bypass branch; the heat transfer fluid circuit has a direct connection between the outlet of the electric heating device and the inlet of the two-fluid heat exchanger, according to the direction of flow of the heat transfer fluid; the flow rate of heat transfer fluid passing through the first heat exchanger and included in the input data is a mass flow rate; Alternatively, the flow rate of heat transfer fluid passing through the first heat exchanger and included in the input data is a volumetric flow rate; said input data also includes the speed of the compression device; The speed of the compression device is communicated via a vehicle communication network; The setpoint temperature for heating the heat transfer fluid at the outlet of the first heat exchanger is communicated via a vehicle communication network; said input data also include a quantity representative of an outside air velocity passing through the front of the vehicle; said refrigerant circuit includes a refrigerant reserve device located on the main loop between the outlet of the first heat exchanger and the inlet of the compression device; said refrigerant reserve device is a gas / liquid separation bottle located on the main loop between the first heat exchanger and the first expansion device; according to one embodiment, said refrigerant reserve device is a gas / liquid separation accumulator located on the main loop between the first junction point and the compression device; said refrigerant circuit includes a third expansion device located between the outlet of the first heat exchanger and the gas / liquid separation vessel; the first trigger mechanism has a variable opening section; the second trigger mechanism has a variable opening section; the third trigger mechanism has a variable opening section; the refrigerant circuit includes a non-return valve in the main loop located between the outlet of the second heat exchanger and the first junction point; the heat transfer fluid passing through the first heat exchanger is interior air destined for the passenger compartment; according to one embodiment of the thermal conditioning system, the heat transfer fluid passing through the first heat exchanger is a heat transfer fluid circulating in a first secondary heat transfer fluid circuit, comprising at least said first heat exchanger and a heating radiator through which interior air passes for the passenger compartment; the process determines said heat transfer fluid setpoint temperature by calculation from the input data; The process determines said heat transfer fluid setpoint temperature from the input data by means of a heat transfer fluid setpoint temperature map, said map being defined beforehand at least according to pre-recorded values ​​of quantities respectively representative of the heating setpoint temperature of the heat transfer fluid at the outlet of the first heat exchanger, values ​​of the outside temperature of the vehicle, values ​​of the heat transfer fluid flow rate through the first heat exchanger, values ​​of the refrigerant fluid pressure located downstream of the second heat exchanger and / or the bi-fluid heat exchanger and upstream of the compression device, values ​​of the heat transfer fluid flow rate through the bi-fluid heat exchanger and values ​​of the heat transfer fluid temperature upstream of the first heat exchanger; according to one embodiment of the process, said mapping is also defined as a function of values ​​of the speed of the compression device; According to one embodiment of the thermal conditioning system, the second heat exchanger evaporates the refrigerant by recovering heat extracted directly from an external airflow to the vehicle. Direct recovery means that the second heat exchanger is a refrigerant / air heat exchanger arranged in an external airflow at the front of the vehicle, the refrigerant receiving the heat extracted from the external airflow within the second heat exchanger, without the intervention of another intermediate heat transfer fluid; according to the embodiment in which the second heat exchanger evaporates the refrigerant by directly recovering heat from the outside air, said mapping is also defined as a function of values ​​of the air velocity passing through the front of the vehicle, said air velocity at the front of the vehicle being here the air velocity outside the vehicle passing through the second heat exchanger; According to one embodiment of the thermal conditioning system, the second heat exchanger evaporates the refrigerant by recovering heat extracted indirectly from an external airflow to the vehicle. Indirect recovery means that the second heat exchanger is a refrigerant / heat transfer fluid exchanger, arranged in a second secondary heat transfer fluid circuit comprising at least one front-facing radiator, said radiator being a heat transfer fluid / air exchanger arranged in the external airflow at the front of the vehicle; Depending on the embodiment in which the second heat exchanger evaporates the refrigerant by indirectly recovering heat from the outside air, the mapping is also defined based on values ​​of the air velocity at the front of the vehicle, said air velocity crossing the front of the vehicle being here the air velocity outside the vehicle passing through the front radiator and also depending on the flow values ​​of the heat transfer fluid in the second secondary heat transfer fluid circuit; the process includes a step of determining an external temperature to the vehicle; the thermal conditioning system includes a temperature sensor to measure the temperature outside the vehicle, an output signal from said sensor being a value of said temperature outside the vehicle; the process includes a step of determining a pressure of the refrigerant fluid downstream of the second heat exchanger and / or the two-fluid heat exchanger and upstream of the compression device; the refrigerant circuit includes a pressure sensor to measure the refrigerant pressure between the outlet of the second heat exchanger and / or the outlet of the dual-fluid heat exchanger and the inlet of the compression device, an output signal of said pressure sensor being a value of said pressure between the second heat exchanger and the inlet of the compression device; the process includes a step of determining a temperature of the heat transfer fluid upstream of the first heat exchanger according to the direction of flow of the heat transfer fluid; the thermal conditioning system includes a temperature sensor for the heat transfer fluid passing through the first heat exchanger, the sensor being upstream of said first heat exchanger, an output signal from said temperature sensor being a value of said temperature of the heat transfer fluid upstream of the first heat exchanger; the process includes a step of estimating the flow rate of heat transfer fluid passing through the first heat exchanger; in an embodiment of the thermal conditioning system in which the heat transfer fluid is interior air for the passenger compartment, the estimation of the heat transfer fluid flow rate through the first heat exchanger is carried out from the value of the blower utilization level, said blower being arranged in a heating, ventilation and / or air conditioning system, frequently referred to by the English term "HVAC", for "Heating, Ventilating and Air Conditioning", said blower utilization level value being transmitted by a vehicle communication network; in an embodiment of the thermal conditioning system in which the heat transfer fluid is a heat transfer liquid circulating in a secondary heat transfer liquid circuit, the estimation of the flow rate of heat transfer liquid passing through the first heat exchanger is carried out from the value of a pump speed, said pump being arranged in said secondary heat transfer liquid circuit, said pump speed value being transmitted by a vehicle communication network; the process includes a step of estimating the speed of outside air passing over the front of the vehicle; the outside air speed passing through the front of the vehicle is estimated from the speed of the vehicle and the speed of a fan at the front of the vehicle, said vehicle and front fan speeds being communicated by a vehicle communication network; the process includes a step of estimating the compression power supplied by the compression device; the compression power supplied by the compression device is estimated from the electrical power consumed by the compressor; The electrical power consumed by the compressor is communicated via a vehicle communication network; the determination of said heat transfer fluid setpoint temperature by calculation includes a step of determining a coefficient representative of the exchange in the two-fluid heat exchanger and dependent on the flow rate of heat transfer fluid passing through said two-fluid heat exchanger; the determination of the representative coefficient of heat exchange in the bifluid heat exchanger is carried out from a table of correspondence of the representative coefficient of heat exchange in the bifluid heat exchanger as a function of values ​​of the flow rate of heat transfer fluid passing through said bifluid heat exchanger; according to one embodiment of the invention, the determination of the coefficient representing the heat exchange in the bifluid heat exchanger is carried out from a correlation between the coefficient representing the heat exchange in the bifluid heat exchanger and the flow rate of heat transfer fluid passing through said bifluid heat exchanger; the determination of said heat transfer fluid setpoint temperature by calculation includes a step of determining a quantity representative of the evaporation power of the refrigerant in the second heat exchanger in the "electric heating and heat pump" mode; the determination of said heat transfer fluid setpoint temperature by calculation includes a step of determining a coefficient representative of the overall heat exchange at the front between the refrigerant fluid passing through the second heat exchanger and the outside airflow passing through the front of the vehicle, said coefficient representative of the overall heat exchange at the front depending on the speed of the outside airflow; the determination of the representative coefficient of the overall heat exchange at the front is carried out from a table of correspondence of the representative coefficient of the overall heat exchange at the front as a function of values ​​of the velocity of outside air passing through the front of the vehicle; the determination of the representative coefficient of the overall heat exchange at the front is carried out from a correlation between the representative coefficient of the overall heat exchange at the front and the speed of outside air passing through the front of the vehicle; according to the embodiment in which the second heat exchanger evaporates the refrigerant by indirectly recovering heat from the outside air, the determination of the representative coefficient of the overall heat exchange at the front is carried out from a table of correspondence of the representative coefficient of the overall heat exchange at the front as a function of values ​​of the speed of outside air passing through the front of the vehicle and as a function of values ​​of the flow rate of heat transfer fluid circulating in the second secondary heat transfer fluid circuit; according to the embodiment in which the second heat exchanger evaporates the refrigerant by indirectly recovering heat from the outside air, the determination of the representative coefficient of the overall heat exchange at the front is carried out from a correlation between the representative coefficient of the overall heat exchange at the front and the speed of outside air passing through the front of the vehicle and the flow rate of heat transfer fluid circulating in the second secondary heat transfer fluid circuit; the determination of said heat transfer fluid setpoint temperature by calculation takes into account a safety factor guaranteeing the obtaining of a minimum value of the heat transfer fluid setpoint temperature; - the process includes a step of regulating the measured temperature of the heat transfer fluid to reach the setpoint temperature value of the heat transfer fluid; - the process sends a heating power instruction to the electric heating device;

[0013] The invention also relates to a computer program comprising instructions which lead the thermal conditioning system to execute the process.

[0014] The invention also relates to a central control unit, said unit comprising at least one computer, a memory, and the computer program stored in the memory. The central control unit is capable of receiving signals from sensors of the climate control system, receiving signals from vehicle communication networks, implementing control laws, and sending control signals to various actuators of the climate control system.

[0015] Finally, the invention also relates to a computer-readable medium on which the computer program is recorded. Brief description of the drawings

[0016] Other features, details and advantages of the invention will become clearer upon reading the following description, which is given by way of illustration only, in conjunction with the accompanying drawings in which:

[0017] [Fig.1] is a schematic view of a thermal conditioning system according to a first embodiment of said system to which the process is applied,

[0018] [Fig.2] is a schematic view of said thermal conditioning system operating in an "electric heating and heat pump" mode,

[0019] [Fig.3] is a schematic view of said thermal conditioning system operating in an "electric heating" mode,

[0020] [Fig.4] represents a first embodiment of the process by mapping,

[0021] [Fig.5] represents a second embodiment of the process by calculation,

[0022] [Fig.6] represents a variant of the second embodiment of the process by calculation,

[0023] [Fig.7] is a liquid setpoint temperature control scheme heat transfer fluid,

[0024] [Fig.8] is a schematic view of a thermal conditioning system according to a second embodiment of said thermal conditioning system,

[0025] [Fig.9] is a schematic view of a thermal conditioning system according to a third embodiment of said thermal conditioning system.

[0026] [Fig. 10] is a schematic view of a thermal conditioning system according to a fourth embodiment of said thermal conditioning system. Description of the implementation methods

[0027] In Figures 1 to 3, lines represent conduits connecting one element of a circuit to another element of said circuit. In Figures 2 to 3, solid and thick lines represent conduits through which fluid or liquid flows. Dashed lines represent conduits through which there is no fluid or liquid flow. Chevrons indicate the direction of flow in the conduits.

[0028] It should first be noted that the figures set out the invention in detail for its implementation, said figures being of course able to serve to better define the invention, if necessary.

[0029] The terms upstream and downstream used in the following description refer to the direction of flow of the fluid considered.

[0030] The terms inlet and outlet used in the following description refer to the direction of flow of the fluid considered.

[0031] To differentiate the components, the terms "first," "second," etc., are used. These terms are not intended to establish a hierarchy or order among the components. They are used for distinction purposes and may be interchanged without affecting the implementation of the invention. For example, the designation "second" does not necessarily imply the presence of two elements.

[0032] A branch is a portion of a circuit connecting one point of the circuit to another point of the circuit.

[0033] When it is specified that a branch includes a given element, this does not exclude the presence of other elements in that branch.

[0034] A conduit is a portion of a circuit connecting one point of the circuit to another point of the circuit, without any element between these two points.

[0035] The term “exchanger” is equivalent to the term “heat exchanger”, and the two terms may be used interchangeably in the following description.

[0036] An "inactive" heat exchanger is understood to be a heat exchanger in which there is no forced heat exchange.

[0037] Fig. 1 illustrates an example of a thermal conditioning system 1 according to the invention comprising a refrigerant circuit 100 FR, a heat transfer fluid circuit 200 LC and a central control unit UC comprising at least one computer, a memory and a computer program stored in the memory, and configured to implement a method 2.

[0038] The central control unit UC receives information from various sensors measuring, in particular, the characteristics of the refrigerant at various points in the circuit, and measuring the characteristics of the airflow, heat transfer fluid, and coolant flow at various points in the thermal conditioning system 100. The electronic control unit UC also receives commands from the vehicle occupants, such as the desired temperature inside the passenger compartment. The electronic control unit UC can also receive commands from other electronic subsystems, such as the battery management system for electrical energy storage. The central control unit UC implements control laws to operate the various actuators, ensuring that the thermal conditioning system 1 is controlled in a way that fulfills the received commands.

[0039] The refrigerant circuit 100 forms a closed circuit in which the refrigerant FR can circulate. The refrigerant circuit 100 is leak-proof when it is in a nominal operating state, i.e., without any fault or leak. Each branch and / or junction point of circuit 100 allows the refrigerant to flow into one of the circuit sections that converge at that point. The refrigerant is distributed between the circuit sections at each junction by opening or closing the shut-off valves, check valves, or expansion valves located on each branch of the circuit. In other words, each branch and junction point is a means of redirecting the refrigerant. Various shut-off valves and check valves thus allow the refrigerant to be selectively directed into the different branches of the refrigerant circuit, in order to ensure different operating modes, as will be described later.

[0040] The refrigerant FR used by the refrigerant circuit 100 is a chemical fluid such as R1234yf. Other refrigerants can also be used instead, such as R134a, R290 or R744.

[0041] The thermal conditioning system 1 comprises a flow Ffc of a heat transfer fluid FC passing through a first heat exchanger of the refrigerant circuit 100. This heat transfer fluid FC can be, for example, interior air destined for the passenger compartment or a heat transfer liquid.

[0042] Interior airflow refers to the airflow directed towards the passenger compartment of a motor vehicle. This interior airflow may circulate within a heating, ventilation, and / or air conditioning (HVAC) system. This system is not shown in the various figures. A first motor-fan unit, not shown, is located within the HVAC system to increase the flow rate of the interior airflow as needed.

[0043] The term "external airflow Fe" refers to an airflow that is not destined for the vehicle's passenger compartment. In other words, this airflow Fe remains outside the vehicle's passenger compartment. Specifically, the external airflow passes through the front of the vehicle. A second fan motor unit, also not shown, can be activated to increase the flow rate of the external airflow Fe passing through the front of the vehicle if necessary. The flow rate provided by both the first and second fan motor units can be adjusted in real time according to heat exchange requirements, for example, by the central control unit UC of the climate control system 1.

[0044] The thermal conditioning system circuit 1 is capable of operating, for example, in several modes allowing the heating of a vehicle's passenger compartment.

[0045] The refrigerant circuit 100 comprises:

[0046] - a main loop A, said main loop A comprising successively depending on the direction of refrigerant flow:

[0047] — a refrigerant fluid compression device 3,

[0048] — a first heat exchanger 4 arranged to be traversed by a flow Ffc of a heat transfer fluid FC and intended to heat said heat transfer fluid FC,

[0049] — a first release mechanism 6

[0050] — a second heat exchanger 5 located between the first heat exchanger 4 of heat and the compression device 3, and intended in particular to evaporate the refrigerant, by recovering heat extracted from an outside airflow, for example directly or indirectly,

[0051] the first expansion valve 6 located between the first heat exchanger 4 and the second heat exchanger 5,

[0052] - a first secondary branch B, connecting a first derivation point dl to a first junction point j 1, said first secondary branch B comprising successively according to the direction of circulation of the refrigerant fluid a second expansion member 8 and a two-fluid heat exchanger 7 arranged in a circuit 200 of heat transfer fluid LC and intended to evaporate the refrigerant FR, said first branch point dl being located between the first heat exchanger 4 and the first expansion member 6, said first junction point j 1 being located between the second heat exchanger 5 and the compression device 3.

[0053] Said LC heat transfer fluid circuit 200 includes an electric heating device 9 for heating said LC heat transfer fluid. In this embodiment of the invention, the heat transfer fluid flow Ffc is an indoor airflow intended to be heated by passing through the first heat exchanger 4, which is then an internal condenser located in the casing of an unshown ventilation, heating and / or air conditioning (“HVAC”) system of which it forms part.

[0054] In an example of an embodiment not shown of the thermal conditioning system 100, the heat transfer fluid FC is a heat transfer fluid intended to be heated by passing through the first heat exchanger 4, which is then a two-fluid condenser located in the environment under the hood of the vehicle arranged in a secondary heat transfer fluid circuit.

[0055] In this example of a refrigerant circuit 100 illustrated in [Fig.1], said refrigerant circuit 100 further comprises a refrigerant accumulation device 10 located on the main loop A between the outlet of the first heat exchanger 4 and the inlet of the first expansion device 6. Said accumulation device 10 comprises a liquid refrigerant storage volume configured to compensate for variations in the quantity of refrigerant circulating in the refrigerant circuit 100 according to the operating conditions. The accumulation device 10 is here a gas / liquid separation cylinder 10'. This cylinder 10' can receive a two-phase mixture of refrigerant at its inlet. In steady state, the refrigerant FR entering the cylinder inlet is in a saturated liquid state, and the refrigerant FR exiting the cylinder outlet is also in a saturated liquid state.

[0056] The refrigerant circuit 100 includes a check valve 11 located between the outlet of the second heat exchanger 5 and the junction point j 1. Said check valve is configured to allow circulation of the refrigerant FR from the outlet of the second heat exchanger 5 to the junction point j 1 and to prohibit any circulation of the refrigerant FR from the junction point j 1 to the outlet of the second heat exchanger 5.

[0057] According to this embodiment example in [Fig.1], the refrigerant circuit 100 includes a third expansion member 12 located between the first heat exchanger 4 and the bottle 10'.

[0058] The expansion devices 6, 8, 12 are, for example, electronic expansion valves with a variable opening area, in which the passage area allowing the refrigerant FR to pass can be continuously adjusted between a closed position and a maximum opening position. To achieve this, an electronic control module for the expansion valve drives an electric motor that moves a movable shutter, controlling the passage area available to the refrigerant FR and thus modifying the pressure drop of the refrigerant FR passing through it. In the closed position, also called the closed position, the circulation of refrigerant FR is interrupted; that is, the flow rate of refrigerant FR through the electronic expansion valve is zero.

[0059] The thermal conditioning system comprises the LC heat transfer fluid circuit 200 including the two-fluid heat exchanger 7 and the device electric heating 9. Said circuit 200 of heat transfer fluid LC further includes a pump 13 for circulating the heat transfer fluid LC within the circuit 200, thus forming a flow Fie of heat transfer fluid within said circuit 200 of heat transfer fluid LC.

[0060] In this example of the thermal conditioning system 1, the second heat exchanger 5 evaporates the refrigerant FR by directly recovering heat extracted from the outside airflow Fe to the vehicle. Direct recovery means that the second heat exchanger 5 is a refrigerant / air heat exchanger integrated into the front of the vehicle and arranged in the outside airflow Fe, with the refrigerant FR receiving the heat extracted from the outside airflow Fe within the second heat exchanger 5, without the intervention of any other intermediate heat transfer fluid.

[0061] According to another embodiment of the thermal conditioning system 1 (not shown), the second heat exchanger 5 evaporates the refrigerant FR by indirectly recovering heat from the external airflow Fe to the vehicle. Indirect recovery means that the second heat exchanger 5 is a refrigerant / heat transfer fluid exchanger located in the under-hood environment, arranged in a second secondary heat transfer fluid circuit comprising at least one front-mounted radiator, said radiator being a heat transfer fluid / air exchanger arranged in the external airflow Fe to the vehicle.

[0062] The thermal conditioning system 1 includes a first temperature sensor Tl for measuring the outside temperature of the vehicle. In this embodiment, said first temperature sensor Tl for measuring the outside temperature of the vehicle is located upstream of the second heat exchanger 5 in the direction of the flow of outside air Fe passing through said second heat exchanger 5. An output signal of said first temperature sensor Tl for measuring the outside temperature Text is the value of said outside temperature Text.

[0063] The thermal conditioning system 1 includes a second temperature sensor T2 for measuring the temperature of the heat transfer fluid Tfcs downstream of the first heat exchanger 4, according to the direction of flow of the heat transfer fluid Ffc. An output signal from said second temperature sensor T2 for measuring the temperature of the heat transfer fluid Tfcs downstream of the first heat exchanger 4 is the value of said temperature of the heat transfer fluid Tfcs downstream of the first heat exchanger 4. As previously stated, in this embodiment, the heat transfer fluid flow Ffc is the interior air flow Fi to the passenger compartment, and the temperature of the heat transfer fluid Tfcs downstream of the first heat exchanger is... heat 4 is therefore an indoor air temperature Tais downstream of the first heat exchanger 4.

[0064] The thermal conditioning system 1 includes a third temperature sensor T3 for measuring the temperature of the heat transfer fluid Tfce upstream of the first heat exchanger 4, according to the direction of flow of the heat transfer fluid Ffc. An output signal from said third temperature sensor T3 for measuring the temperature of the heat transfer fluid Tfce upstream of the first heat exchanger 4 is the value of said temperature of the heat transfer fluid Tfce upstream of the first heat exchanger 4. As previously stated, in this embodiment, the heat transfer fluid flow Ffc is the interior air flow Fi to the passenger compartment; therefore, the temperature of the heat transfer fluid Tfce upstream of the first heat exchanger 4 is an interior air temperature Taes upstream of the first heat exchanger 4.

[0065] The refrigerant circuit 100 includes a pressure sensor PI for measuring the pressure Prce of the refrigerant FR downstream of the second heat exchanger 5 and / or the bifluid heat exchanger 7 and upstream of the compression device 3, said pressure sensor PI being located on the main loop A between the first junction point j1 and the inlet of the compression device 3. An output signal of said pressure sensor PI is the value of the pressure Prce downstream of the second heat exchanger 5 and / or the bifluid heat exchanger 7 and upstream of the compression device 3.

[0066] The LC heat transfer fluid circuit 200 includes a fourth temperature sensor T4 for measuring the temperature Thvch of the LC heat transfer fluid downstream of the electric heating device 9, according to the direction of the heat transfer fluid flow Fie. An output signal from said fourth temperature sensor T4 for measuring the temperature Thvch of the LC heat transfer fluid downstream of the electric heating device 9 is the value of said temperature Thvch of the LC heat transfer fluid downstream of the electric heating device 9.

[0067] According to one embodiment of the thermal conditioning system 100, the thermal conditioning system 100 includes a fifth temperature sensor T5, not shown, for measuring the temperature of the refrigerant fluid Trce upstream of the compression device 3, said fifth temperature sensor T5 being located on the main loop A between the first junction point j1 and the inlet of the compression device 3. An output signal from said fifth pressure sensor T5 for measuring the temperature Trce of the refrigerant fluid FR at the inlet of the compression device 3 is the value of the temperature Trce at the inlet of the compression device 3. This temperature measurement is used in particular for superheat control at the inlet of the compression device 3.

[0068] Figure 2 illustrates an example of the implementation of the thermal conditioning system. 100 operating in a heating mode called "heat pump and electric heating" mode, in which on the one hand the electric heating device 9 is active and serves as a heat source to heat the heat transfer fluid LC and evaporate the refrigerant FR in the two-fluid heat exchanger 7, and in which on the other hand the outside air flow Fe serves as a heat source to evaporate the refrigerant FR in the second heat exchanger 5, all the heat taken up by the two-fluid heat exchanger 7 and by the second heat exchanger 5 being returned by the first heat exchanger 4 to the heat transfer fluid FC passing through it, thanks to the compression of the refrigerant FR within the compression device 3. In the "heat pump and electric heating" mode, the refrigerant FR circulates in the main loop A and the first secondary branch B. This refrigerant FR is compressed in the compression device 3, then passes through the first heat exchanger 4 where it transfers heat to the incoming indoor air flow Ffc, Fi. The refrigerant FR then passes through the third expansion device 12 where it undergoes a first expansion, known as pre-expansion, before entering the storage device 10. In this embodiment, as previously mentioned, the storage device 10 is a gas / liquid separation cylinder 10'. The total flow of refrigerant FR exiting the cylinder 10' is split into a first flow of refrigerant FR and a second flow of refrigerant FR at the first branch point dl.The first flow enters the first expansion chamber 6 where it undergoes a second expansion, known as the main expansion, before entering the second heat exchanger 5 where it evaporates and absorbs heat from the outside air flow Fe. This first fluid flow passes through the non-return valve 11 before reaching the junction point j1. The second fluid flow takes the first secondary branch B from the bypass point d1 and reaches the second expansion chamber 8 where it undergoes an expansion before entering the two-fluid heat exchanger 7 where it evaporates and absorbs heat from the heat transfer fluid flow Fie. This second fluid flow then reaches the first junction point j1. The first flow mixes with the second flow at the junction point j1. The total refrigerant flow FR then returns to the inlet of the compression device 3.Within the heat transfer circuit 200, the pump 13 circulates the heat transfer fluid LC to create a flow of heat transfer fluid Fie passing successively through the electric heating device 9 and the bi-fluid heat exchanger 7. The electric heating device is active and heats the heat transfer fluid LC as it passes through it.

[0069] Figure 3 illustrates an example of the implementation of the thermal conditioning system. 100 operating in a mode known as "electric heating" mode, in which the The electric heating device is active and serves as a heat source to heat the heat transfer fluid LC and evaporate the refrigerant FR in the two-fluid heat exchanger, the heat being returned by the first heat exchanger to the heat transfer fluid FC passing through it, thanks to the compression of the refrigerant FR within the compression device 3, without circulation of refrigerant FR within the second heat exchanger 5. In the "electric heating" mode, the refrigerant FR circulates in a portion of the main loop A and in the first secondary branch B. This refrigerant FR is compressed in the compression device 3, then passes through the first heat exchanger 4 where it transfers heat to the incoming indoor air flow Ffc,Fi. The refrigerant FR then passes through the third expansion valve 12 where it undergoes a first expansion, known as pre-expansion, before entering the storage device 10. In this embodiment, as previously mentioned, the storage device 10 is a gas / liquid separation cylinder 10'. The refrigerant FR enters the first secondary branch B from the branch point dl and reaches the second expansion valve 8 where it undergoes expansion before entering the two-fluid heat exchanger 7 where it evaporates and absorbs heat from the heat transfer fluid flow Fie.The refrigerant FR then enters the inlet of the compression unit 3. Within the heat transfer circuit 200, the pump 13 circulates the heat transfer fluid LC to create a flow of heat transfer fluid Fie that successively passes through the electric heating unit 9 and the two-fluid heat exchanger 7. The electric heating unit is active and heats the heat transfer fluid LC as it passes through it. The first expansion valve 6 is in a fully closed position to prevent any circulation of refrigerant fluid in the second heat exchanger 5, said second heat exchanger 5 being inactive at this time.

[0070] In the "heat pump and electric heating" and "electric heating" operating modes, the electric heating device 9 heats the heat transfer fluid flow Fie passing through it until a measured heat transfer fluid temperature Tm in the heat transfer fluid circuit reaches a heat transfer fluid setpoint temperature Thvch_sp. In this embodiment of the invention, the measured heat transfer fluid temperature Tm is the heat transfer fluid temperature Thvch at the outlet of the electric heating device 9. The method 2 according to the invention makes it possible to determine said heat transfer fluid setpoint temperature Thvch_sp, leading to minimal consumption of the electric heating device 9 while ensuring the heating performance required of the thermal conditioning system 1, in particular the achievement of a setpoint temperature. heating of the heat transfer fluid Tfcs_sp by the heat transfer fluid downstream of the first heat exchanger 4 according to the direction of the heat transfer fluid flow Ffc.

[0071] Figures 4 and 5 illustrate respectively a first and a second embodiment of the process 2 for determining the setpoint temperature of the heat transfer fluid Thvch_sp in the "electric heating" and "electric heating and heat pump" modes from input data.

[0072] Said input data include representative quantities of: - the setpoint temperature for heating the heat transfer fluid Tfcs_sp at the outlet of the first heat exchanger 4, - the outside temperature of the vehicle (Text), - a flow rate of heat transfer fluid Qfc passing through the first heat exchanger 4, - the pressure of the refrigerant fluid Prce downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3, - a flow rate of heat transfer fluid Qlc passing through the two-fluid heat exchanger 7, - the temperature of the heat transfer fluid Tfce passing through the first heat exchanger 4, upstream of said first heat exchanger 4, - a compression power Pw_cpr transmitted to the refrigerant FR by the compression device 3.

[0073] In this example embodiment of the thermal conditioning system 1, said input data also include: - the rotational speed of the compression device 3, - the speed of outside air Vae passing through the front of the vehicle. In this example, the heat transfer fluid passing through the first heat exchanger 4 is the interior airflow Fi destined for the passenger compartment. Thus: - the heating setpoint temperature Tfcs_sp of the heat transfer fluid FC at the outlet of the first heat exchanger 4 is a heating setpoint temperature of the indoor air at the outlet of the first heat exchanger 4, - the flow rate of heat transfer fluid Qfc passing through the first heat exchanger 4 is an indoor air flow rate passing through the first heat exchanger 4, - the temperature of the heat transfer fluid Tfce passing through the first heat exchanger 4, upstream of said first heat exchanger 4 is an indoor air temperature passing through the first heat exchanger 4, upstream of said first heat exchanger 4.

[0074] The indoor air heating setpoint value Tfc_sp at the outlet of the first heat exchanger 4 is determined by the central control unit UC according to the conditions and the cabin temperature setpoint.

[0075] The value of the outside temperature of the vehicle Text is determined from the first temperature sensor Tl for measuring the outside temperature of the vehicle, the output signal of said first temperature sensor Tl corresponding to the value of said outside temperature of the vehicle Text is transmitted to the central control unit UC.

[0076] The interior airflow rate Qfc is determined from the blower operating level Lvl using a lookup table defined beforehand and stored in the memory of the central control unit UC. This table indicates an interior airflow rate Qfc at least according to the blower operating level Lvl and according to, for example, a temperature of the interior airflow and / or the air distribution selected at the outlet of the heating, ventilation and / or air conditioning system. The blower operating level Lvl and air distribution information is communicated via a vehicle communication network to the central control unit UC.

[0077] The pressure of the refrigerant fluid Prce downstream of the second heat exchanger and / or the two-fluid heat exchanger 7 and upstream of the compression device 3 is determined by the pressure sensor PI measuring the pressure Prce of the refrigerant fluid FR downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3, the output signal of said pressure sensor PI corresponding to the value of the pressure Prce downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3 is transmitted to the central control unit UC.

[0078] The value of the heat transfer fluid flow rate Qlc through the two-fluid heat exchanger 7 is communicated to the central control unit UC via a vehicle communication network. According to another embodiment, the value of the heat transfer fluid flow rate Qlc through the two-fluid heat exchanger 7 is determined from the speed of the heat transfer circuit pump 200, said pump speed being communicated to the central control unit UC via a vehicle communication network.

[0079] The indoor air temperature value Tfce passing through the first heat exchanger 4, upstream of said first heat exchanger 4, is determined from the third indoor air temperature sensor T3 upstream of the first heat exchanger 4 according to the direction of circulation of the indoor air flow Ffc passing through the first heat exchanger 4, the output signal of said third temperature sensor T3 corresponding to the value of said temperature Heat transfer fluid Tfce upstream of the first heat exchanger 4 is transmitted to the central control unit UC.

[0080] The compression power value Pw_cpr supplied by the compression device 3 is determined by the central control unit UC from the electrical power value Pw_el consumed by the compression device 3 and communicated to the central control unit UC via a vehicle communication network. This determination is based on a correlation in which the compression power Pw_cpr is proportional to the electrical power Pw_el according to a proportionality coefficient Eff_ad with a value between 0.7 and 0.98.According to another embodiment, the value of the compression power Pw_cpr supplied by the compression device 3 is determined from the speed of the compression device 3, the pressure of the refrigerant fluid at the inlet of the compression device 3, the temperature of the refrigerant fluid at the inlet of the compression device 3, the pressure of the refrigerant fluid at the outlet of the compression device 3 and the temperature of the refrigerant fluid at the outlet of the compression device 3. .

[0081] The value of the speed of the compression device 3 is communicated to the central control unit UC via a vehicle communication network.

[0082] The value of the external air velocity Vae passing through the front of the vehicle is determined from the vehicle speed and the speed of the fan in the front of the vehicle, said vehicle and fan speeds being communicated to the central control unit UC by a vehicle communication network.

[0083] All the input data necessary for the application of the process are thus available in the central control unit UC.

[0084] Figure 4 illustrates a first embodiment of process 2, in which process 2 includes a step of determining, by means of a mapping (MAP), the setpoint temperature of the heat transfer fluid Thvch_sp in the "electric heating" and "electric heating and heat pump" modes. This mapping is a lookup table comprising several dimensions, each dimension corresponding to an input data point. Each dimension of the mapping comprises a multitude of pre-recorded values ​​of the input data corresponding to said dimension.

[0085] Each combination of pre-recorded values ​​of said input data corresponds to a setpoint temperature value of the heat transfer fluid Thvch_sp. Any combination of values ​​of the input data of the map is achievable by interpolation and / or extrapolation within the "MAP" map of the pre-recorded values ​​of each input data.

[0086] The "MAP" mapping is defined beforehand and recorded on a memory of the central control unit UC.

[0087] The preliminary definition of said MAP mapping is based, for example, on theoretical calculations and / or laboratory tests and / or tests under real-world conditions which have made it possible to determine the setpoint temperature value of the heat transfer fluid Thvch_sp leading to the minimization of overall electrical consumption for a multitude of combinations of input data values. Overall electrical consumption is understood to be the sum of the electrical consumption of the compression device 3 and the electric heating device 9.

[0088] With all input data available at the central control unit UC, process 2 performs a step of determining the setpoint temperature of the heat transfer fluid Thvch_sp according to the MAP map. Said determined value of setpoint temperature of the heat transfer fluid Thvch_sp is the value leading to the minimum overall electrical consumption while ensuring the heating performance required by the thermal conditioning system, in particular reaching the setpoint temperature of the interior air Tfcs_sp at the outlet of the first heat exchanger 4, consequently ensuring the setpoint temperature required at the passenger compartment level.

[0089] Figure 5 illustrates a second embodiment of process 2, in which process 2 includes a step for calculating the setpoint temperature of the heat transfer fluid Thvch_sp in the "electric heating" and "electric heating and heat pump" modes, using the same input data as described previously for the first embodiment of process 2 by the "MAP" mapping. This calculation of the setpoint temperature of the heat transfer fluid Thvch_sp is notably performed by the central control unit UC.

[0090] The calculation of the setpoint temperature of the heat transfer fluid Thvch_sp at the outlet of the electric heating device 9 in the "electric heating" and "electric heating and heat pump" modes uses the following equation EQ1: Thvch_sp=Tsat(Prce)+ a+

[0092] With: - Thvch_sp the setpoint temperature of the liquid; - Tsat (Prce) the saturation temperature of the refrigerant FR at the refrigerant pressure Prce downstream of the second heat exchanger 5 and / or the bifluid heat exchanger 7 and upstream of the compression device 3; - has a safety factor guaranteeing a minimum setpoint temperature, and whose value is between 3°C and 10°C; - Qfc the flow rate of heat transfer fluid passing through the first heat exchanger 4; - Tfcs_sp the setpoint temperature of the heat transfer fluid downstream of the first heat exchanger 4 according to the direction of the heat transfer fluid flow Ffc; - Tfce the temperature of the heat transfer fluid upstream of the first heat exchanger 4 according to the direction of the heat transfer fluid flow Ffc; - Cp_fc the heat capacity at constant pressure of the heat transfer fluid in the first heat exchanger 4; - Pw_evcd the evaporation power of the refrigerant in the second heat exchanger 5; - Pw_cpr the compression power transmitted to the refrigerant in the compression device 3; - SL_ch a coefficient representing the heat exchange within the bifluid heat exchanger 7 and dependent on the flow rate of heat transfer fluid Qlc passing through said bifluid heat exchanger 7.

[0093] In "electric heating" mode, with the second heat exchanger 5 inactive, the evaporation power Pw_evcd of the refrigerant in the second heat exchanger 5 is zero. Equation EQ1 for calculating the setpoint temperature of the heat transfer fluid Thvch_sp is thus simplified to equation EQ1': [00941 mi” . Qfc*(Tfcs sp-Tfce)*Cp fc-Pw cpr L J Thvch_sp=Tsat(Prce)+ a+ -—---

[0095] The process 2 includes a step of determining the representative heat transfer coefficient SL_ch within the two-fluid heat exchanger 7. This representative coefficient SL_ch depends on the value of the heat transfer fluid flow rate Qlc passing through said two-fluid heat exchanger 7. Preferably, said representative heat transfer coefficient is determined using a lookup table between the representative heat transfer coefficient SL_ch and the heat transfer fluid flow rate Qlc passing through the two-fluid heat exchanger 7, said table being stored in the central control unit UC. This lookup table comprises a multitude of pre-recorded values.Any value of the representative heat transfer coefficient SL_ch can be determined by interpolating the pre-recorded values ​​of said correspondence table between the representative heat transfer coefficient SL_ch and the flow rate of heat transfer fluid Qlc passing through the bifluid heat exchanger 7. .

[0096] The process 2 includes a step of determining the saturation temperature Tsat (Prce) of the refrigerant at the refrigerant pressure Prce downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3, from the pressure value The process is located downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3. In particular, said step of determining the saturation temperature uses a lookup table between the pressure of the refrigerant and the saturation temperature of said refrigerant, said table being stored in the central control unit UC. Said lookup table comprises a multitude of pre-recorded values. Any saturation temperature value of the refrigerant is determinable by interpolating the pre-recorded values ​​of said lookup table between the pressure of the refrigerant and the saturation temperature of said refrigerant.

[0097] The process 2 includes a step of determining the evaporation power Pw_evcd in the second heat exchanger 5 from the outside air velocity Vae passing through the second heat exchanger 5, the outside temperature Text and the pressure Prce of the refrigerant fluid downstream of the second heat exchanger 5 and / or the bi-fluid heat exchanger 7 and upstream of the compression device 3. In particular, the evaporation power is determined by calculation by the central control unit UC according to the following equation:

[0098] Pw_evcd= SLevcd^Text-Tsat^Prce)}

[0099] With: - Pw_evcd the evaporation power in the second heat exchanger 5, - SL_evcd is a coefficient representing the overall heat exchange at the front of the vehicle and dependent on the Vae velocity of outside air passing through the front of the vehicle, - Text the outside temperature of the vehicle, - Tsat(Prce) is the saturation temperature of the refrigerant at the refrigerant pressure Prce downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3.

[0100] In order to determine the evaporation power Pw_evcd in the second heat exchanger 5, the process 2 includes a step of determining the representative coefficient of the overall heat exchange at the front of the vehicle SL_evcd. This representative coefficient SL_evcd depends on the value of the outside air velocity Vae passing through the front of the vehicle. In this embodiment, the second heat exchanger 5 recovers the heat extracted from the outside airflow Fe directly; the outside air velocity Vae passing through the front of the vehicle is here the outside air velocity passing through the second heat exchanger 5.Preferably, the said representative coefficient of the overall heat exchange in the front face SL_evcd is determined using a correspondence table between the said representative coefficient of . The overall heat exchange coefficient at the front of the vehicle SL_evcd and the outside air velocity Vae are represented in the central control unit UC. This lookup table comprises a multitude of pre-recorded values. Any value of the representative coefficient of the overall heat exchange coefficient at the front of the vehicle SL_evcd can be determined by interpolating the pre-recorded values ​​in this lookup table between the representative coefficient of the overall heat exchange coefficient at the front of the vehicle SL_evcd within the second heat exchanger 5 and the outside air velocity Vae passing through the front of the vehicle.

[0101] According to an example of an embodiment not shown of the thermal conditioning system 1 in which the second heat exchanger 5 indirectly recovers heat extracted from the outside airflow Fe, the velocity Vae of outside air passing through the front of the vehicle is here the velocity of the outside airflow passing through a front-end radiator. In said example of an embodiment, the coefficient representing the overall heat exchange at the front, SL_evcd, depends on the outside air velocity Vae passing through the radiator and the flow rate of heat transfer fluid passing through the second heat exchanger 5, and is determined using a lookup table.

[0102] Figure 6 illustrates a variant of the second embodiment of process 2, in which the setpoint temperature of the heat transfer fluid Thvch_sp in the "electric heating" and "electric heating and heat pump" modes corresponds to the following equation EQ2: Thvch_sp=kl*Tsat(Prce) + a+ + k2* T ex t With : - Thvch_sp the setpoint temperature of the heat transfer fluid; - kl a first coefficient dependent on the coefficient representing the overall heat exchange on the front face and dependent on the coefficient representing the heat exchange within the bifluid heat exchanger 7; - Tsat (Prce) the saturation temperature of the refrigerant at the refrigerant pressure Prce downstream of the second heat exchanger 5 and / or the two-fluid heat exchanger 7 and upstream of the compression device 3; - has a safety factor guaranteeing a minimum setpoint temperature, and whose value is between 3°C and 10°C; - Qfc the flow rate of heat transfer fluid passing through the first heat exchanger 4; - Tfcs_sp the setpoint temperature of the heat transfer fluid downstream of the first heat exchanger 4 according to the direction of the heat transfer fluid flow Ffc; - Tfce the temperature of the heat transfer fluid upstream of the first heat exchanger 4 according to the direction of the heat transfer fluid flow Ffc; - Cp_fc the heat capacity at constant pressure of the heat transfer fluid in the first heat exchanger 4; - k2 a second coefficient dependent on the heat exchange coefficient within the second heat exchanger 5 and dependent on the heat exchange coefficient within the bifluid heat exchanger 7; - Text the outside temperature of the vehicle; - SL_ch a coefficient representing the heat exchange within the bifluid heat exchanger 7 and dependent on the flow rate of heat transfer fluid Qlc passing through said bifluid heat exchanger 7.

[0103] Fig. 7 illustrates a power regulation diagram of the electric heating device 9.

[0104] The process 2 includes a step of regulating a power Phvch of the electric heating device 9 so that the measured heat transfer fluid temperature Thvch reaches the heat transfer fluid setpoint temperature Thvch_sp.

[0105] In this embodiment example, the measured heat transfer fluid temperature Tm in the heat transfer fluid circuit is the heat transfer fluid temperature Thvch at the outlet of the electric heating device 9 according to the direction of flow of the heat transfer fluid Fie in the heat transfer fluid circuit 200.

[0106] The value of the heat transfer fluid temperature Thvch is determined from the fourth temperature sensor T4 measuring the temperature of the heat transfer fluid Thvch at the outlet of the electric heating device 9, the output signal of said fourth temperature sensor T4 corresponding to the value of said temperature of the heat transfer fluid Thvch at the outlet of the electric heating device 9 is transmitted to the central control unit UC.

[0107] Once the setpoint temperature of the heat transfer fluid Thvch_sp has been determined, the process 2 includes a step of comparing said setpoint temperature of the heat transfer fluid Thvch_sp and the measured temperature of the heat transfer fluid Thvch.

[0108] The central control unit UC includes an RPI controller which determines a setpoint for the heating power Phvch to be sent to the electric heating device 9 according to the result of said comparison step.

[0109] If the measured temperature Thvch is less than the setpoint temperature Thvch_sp - [3, with [3 being a constant whose value is between 0°C and 5°C the process then includes a step of increasing the heating power Phvch of the electric heating device 9.

[0110] If the measured temperature Thvch is greater than the setpoint temperature Thvch_sp + [3, with [3 being a constant whose value is between 0°C and 5°C, the process then includes a step of reducing the heating power Phvch of the electric heating device 9.

[0111] If the measured temperature Thvch is between the setpoint temperature Thvch_sp - [3 and the setpoint temperature Thvch_sp + [3, with [3 being a constant whose value is between 0°C and 5°C, the process then includes a step of maintaining the heating power Phvch of the electric heating device 9.

[0112] Fig. 8 illustrates a second embodiment of the thermal conditioning system 1 to which process 2 is applied.

[0113] Said second embodiment of the thermal conditioning system 1 differs from the first embodiment in that the main loop A of the refrigerant circuit is devoid of the third expansion member 12 located between the outlet of the first heat exchanger 4 and the inlet of the bottle 10'.

[0114] Fig. 9 illustrates a third embodiment of the thermal conditioning system to which process 2 is applied.

[0115] Said third embodiment of the thermal conditioning system 1 differs from the first embodiment in that the refrigerant accumulation device 10 is an accumulator 10” located between the first junction point j1 and the inlet of the compression device 3. Said accumulator 10” can receive at its inlet a two-phase mixture of refrigerant. In steady state, the refrigerant FR arriving at the inlet of the accumulator is in a two-phase state and the refrigerant FR exiting the outlet of the accumulator is in a saturated gas state.

[0116] Fig. 10 illustrates a fourth embodiment of the thermal conditioning system to which process 2 is applied.

[0117] Said fourth embodiment of the thermal conditioning system 1 differs from the first embodiment in that the heat transfer fluid circuit 200 comprises a third heat exchanger 14 thermally coupled with a traction chain element. The traction chain element comprises, for example, an electrical energy storage battery.

[0118] The heat transfer fluid circuit 200 includes a bypass means 15 of the third heat exchanger 14.

[0119] The heat transfer fluid circuit 200 includes a bypass branch of the third heat exchanger, connecting a second divergence point d2 located between the outlet of the bifluid heat exchanger 12 and the inlet of the third heat exchanger 14 to a second junction point j2 located between the outlet of the third heat exchanger and the inlet of the electric heating device 9.

[0120] The bypass means 15 is here a three-way valve located at the second divergence point d2, and having a first outlet towards the inlet of the third heat exchanger 14 and a second outlet towards the bypass branch.

[0121] The bypass means 15 allows the circulation of the heat transfer fluid through the heat exchanger 14 and prevents the circulation of the heat transfer fluid in the bypass branch when it is desired to take advantage of the heat released by the traction chain element coupled to the third heat exchanger 12 to heat the heat transfer fluid, with or without additional heat from the electric heating device 9.

[0122] The bypass means 15 allows the circulation of the heat transfer fluid in the bypass branch and prevents the circulation of the heat transfer fluid through the heat exchanger 14 when it is desired to heat the heat transfer fluid only with the help of the electric heating device 9. This prevents the third heat exchanger 14 from absorbing part of the heat generated by the electric heating device, in particular because of the large thermal inertia which could characterize the traction chain element to which the third heat exchanger 14 is coupled.

Claims

1. Demands Method (2) for controlling a thermal conditioning system (1) of a vehicle, said system comprising a refrigerant (FR) circuit (100) and a heat transfer fluid circuit (200), said refrigerant (FR) circuit (100) comprising: - A main loop (A), said main loop (A) comprising successively, according to the direction of circulation of the refrigerant: — a refrigerant compression device (3), — a first heat exchanger (4) arranged to be traversed by a flow (Ffc) of a heat transfer fluid (FC) and intended to heat said heat transfer fluid, — a first release mechanism (6), — a second heat exchanger (5) located between the first heat exchanger (4) and the compression device (3), intended to evaporate the refrigerant (FR), by recovering heat extracted from an outside air flow (Fe), directly or indirectly, said first expansion device (6) being located between the first heat exchanger (4) and the second heat exchanger (5), - a first secondary branch (B), connecting a first branch point (dl) to a first junction point (jl), said first secondary branch (B) comprising successively according to the direction of circulation of the refrigerant a second expansion member (8), a two-fluid heat exchanger (7) arranged in the heat transfer fluid circuit (200) and intended to evaporate the refrigerant (FR), said first branch point (dl) being located between the first heat exchanger (4) and the first expansion member (6), said first junction point (j1) being located between the second heat exchanger (5) and the compression device (3), said heat transfer fluid circuit (200) comprising an electric heating device (9) for heating said heat transfer fluid (HL), said thermal conditioning system (1) being configured to operate in an "electric heating" mode, or in an "electric heating and heat pump" mode: - said "electric heating" mode being a mode in which the electric heating device (9) is active and serves as a heat source to heat the heat transfer fluid (HL) and evaporate the refrigerant (RF) in the two-fluid heat exchanger (7), the heat being returned by the first heat exchanger (4) to the heat transfer fluid (HF) passing through it, thanks to the compression of the refrigerant (RF) within the compression device (3), the second heat exchanger (5) being inactive, said "electric heating and heat pump" mode being a mode in which, on the one hand, the electric heating device (9) is active and serves as a heat source to heat the heat transfer fluid (HL) and evaporate the refrigerant (RF) in the two-fluid heat exchanger (7), and in which, on the other hand, outside air serves as a heat source to evaporate the refrigerant (RF) in the second heat exchanger (5), all the heat extracted by the two-fluid heat exchanger (7) and by the second heat exchanger (5) being transferred by the first heat exchanger (4) to the heat transfer fluid (HF) passing through it, thanks to the compression of the refrigerant within the compression device (3), said process comprising, in the "electric heating" and "electric heating and heat pump" modes,a control of the power of the electric heating device (9) so that a measured heat transfer fluid temperature (Tm) in the heat transfer fluid circuit reaches a heat transfer fluid setpoint temperature (Thvch_sp), characterized in that said heat transfer fluid setpoint temperature (Thvch_sp) is determined from input data, said input data comprising representative quantities:, - a heating setpoint temperature (Tfcs_sp) of the heat transfer fluid (FC) at the outlet of the first heat exchanger (4), - an outside temperature of the vehicle (Text), - a heat transfer fluid flow rate (Qfc) through the first heat exchanger (4), - a refrigerant fluid pressure (Prce) located downstream of the second heat exchanger (5) and / or the bi-fluid heat exchanger (7) and upstream of the compression device (3), - a heat transfer fluid flow rate (Qlc) through the bi-fluid heat exchanger (7), - a heat transfer fluid temperature (Tfce) passing through the first heat exchanger upstream of the first heat exchanger, - a compression power (Pw_cpr) supplied by the compression device (3).

2. Method (2) according to the preceding claim, wherein the measured heat transfer fluid temperature (Tm) is a heat transfer fluid temperature at the outlet of the electric heating device (9), according to the direction of flow of the heat transfer fluid in the heat transfer fluid circuit (200).

3. Method (2) according to claim 1, wherein the measured heat transfer fluid temperature (Tm) is a heat transfer fluid temperature at the inlet of the two-fluid heat exchanger (7), according to the direction of flow of the heat transfer fluid in the heat transfer fluid circuit (200).

4. Method (2) according to claim 1, wherein the measured heat transfer fluid temperature (Tm) is a heat transfer fluid temperature at the outlet of the two-fluid heat exchanger (7), according to the direction of flow of the heat transfer fluid in the heat transfer fluid circuit (200).

5. Method (2) according to any one of the preceding claims, wherein the input data also include a quantity representative of an outside air velocity (Vae) passing through the front face of the vehicle.

6. Method (2) according to any one of the preceding claims, wherein the input data also include the velocity (Ncpr) of the compression device (3).

7. Method (2) according to any one of the preceding claims, wherein the heat transfer fluid setpoint temperature (Thvch_sp) is determined by a mapping (“MAP”) of values.

8. Method (2) according to any one of claims 1 to 6, wherein the heat transfer fluid setpoint temperature (Thvch_sp) is determined by calculation.

9. A method (2) according to the preceding claim, wherein the calculation of the heat transfer fluid setpoint temperature (Thvch_sp) is performed according to the following equation (EQ1): , _ , _ . Qfc*(Tfcs sp-Tfce^Cp fc-Pw evcd-Pw cpr Thvch_sp-Tsat(Prce)+ a+ - SL With : - (Thvch_sp) the heat transfer fluid setpoint temperature; - (Tsat (Prce)) the refrigerant saturation temperature at the refrigerant pressure (Prce) downstream of the second heat exchanger (5) and / or the two-fluid heat exchanger (7) and upstream of the compression device (3); - (a) a safety factor guaranteeing a minimum setpoint temperature, the value of which is between 3°C and 10°C; - (Qfc) the heat transfer fluid flow rate through the first heat exchanger (4); - (Tfcs_sp) the heat transfer fluid setpoint temperature downstream of the first heat exchanger (4) according to the direction of the heat transfer fluid flow (Ffc); - (Tfce) the heat transfer fluid temperature upstream of the first heat exchanger (4) according to the direction of the heat transfer fluid flow (Ffc); - (Cp_fc) the heat capacity at constant pressure of the heat transfer fluid in the first heat exchanger (4);- (Pw_evcd) the evaporation power of the refrigerant in the second heat exchanger (5); - (Pw_cpr) the compression power transmitted to the refrigerant in the compression device (3); - (SL_ch) a coefficient representing the heat exchange within the two-fluid heat exchanger (7) and dependent on the flow rate of the heat transfer fluid (Qlc) passing through said two-fluid heat exchanger (7).

10. A method (2) according to claim 8, wherein the calculation of the setpoint temperature of the heat transfer fluid (Thvch_sp) at the outlet of the electric heating device (9) is carried out according to the following equation (EQ2): Qtc*(Tfcs„rTfc^*Cp, Thvchsp= kl*Tsat(Prce) + a+ SL i G+k2*Text With :

11. - (Thvch_sp) the setpoint temperature of the heat transfer fluid at the outlet of the electric heating device (9); - (kl) a first coefficient depending on the heat exchange coefficient within the second heat exchanger (5) and depending on the heat exchange coefficient within the bifluid heat exchanger (7); - (Tsat (Prce)) the saturation temperature of the refrigerant at the refrigerant pressure (Prce) downstream of the second heat exchanger (5) and / or the two-fluid heat exchanger (7) and upstream of the compression device (3); - (a) a safety factor guaranteeing a temperature minimum setpoint, and whose value is between 3°C and 10°C. - (Qfc) the flow rate of heat transfer fluid passing through the first heat exchanger (4); - (Tfcs_sp) the setpoint temperature of the heat transfer fluid downstream of the first heat exchanger (4) according to the direction of the heat transfer fluid flow (Ffc); - (Tfce) the temperature of the heat transfer fluid upstream of the first heat exchanger (4) according to the direction of the heat transfer fluid flow (Ffc); - (Cp_fc) the heat capacity at constant pressure of the heat transfer fluid in the first heat exchanger (4); - (SL_ch) a coefficient representing the heat exchange within the bifluid heat exchanger (7) and dependent on the flow rate of heat transfer fluid (Qlc) passing through said bifluid heat exchanger (7); - (k2) a second coefficient depending on the coefficient of heat exchange within the second heat exchanger (5) and dependent on the heat exchange coefficient within the bifluid heat exchanger (7); - (Text) the outside temperature of the vehicle. Thermal conditioning system (1) comprising a refrigerant (FR) circuit (100) and a circuit (200) heat transfer fluid, said refrigerant circuit (100) comprising: - A main loop (A), said main loop (A) comprising successively, according to the direction of circulation of the refrigerant: — a refrigerant compression device (3), — a first heat exchanger (4) arranged to be traversed by a flow (Ffc) of a heat transfer fluid (FC) and intended to heat said heat transfer fluid, — a first release mechanism (6), — a second heat exchanger (5) located between the first heat exchanger (4) and the compression device (3), intended to evaporate the refrigerant (FR), by recovering heat extracted from an outside air flow (Fe), directly or indirectly, said first expansion device (6) being located between the first heat exchanger (4) and the second heat exchanger (5), - a first secondary branch (B), connecting a first branch point (dl) to a first junction point (jl), said first secondary branch (B) comprising successively according to the direction of circulation of the refrigerant a second expansion member (8), a two-fluid heat exchanger (7) arranged in the heat transfer fluid circuit (200) and intended to evaporate the refrigerant (FR), said first branch point (dl) being located between the first heat exchanger (4) and the first expansion member (6), said first junction point (j1) being located between the second heat exchanger (5) and the compression device (3), said heat transfer fluid circuit (200) comprising an electric heating device (9) for heating said heat transfer fluid (HL), said thermal conditioning system (1) being configured to operate in an "electric heating" mode, or in an "electric heating and heat pump" mode: - said "electric heating" mode being a mode in which the electric heating device (9) is active and serves as a heat source to heat the heat transfer fluid (HL) and evaporate the refrigerant (RF) in the two-fluid heat exchanger (7), the heat being returned by the first heat exchanger (4) to the heat transfer fluid (HF) passing through it, thanks to the compression of the refrigerant (RF) within the compression device (3), the second heat exchanger (5) being inactive, said "electric heating and heat pump" mode being a mode in which, on the one hand, the electric heating device (9) is active and serves as a heat source to heat the heat transfer fluid (HL) and evaporate the refrigerant (RF) in the two-fluid heat exchanger (7), and in which, on the other hand, outside air serves as a heat source to evaporate the refrigerant (RF) in the second heat exchanger (5), all the heat extracted by the two-fluid heat exchanger (7) and by the second heat exchanger (5) being returned by the first heat exchanger (4) to the heat transfer fluid (HF) passing through it, thanks to the compression of the refrigerant within the compression device (3), the thermal conditioning system comprising a central control unit (CU), said unit (CU) comprising at least one computer,a memory and at least one computer program stored in the memory comprising instructions that cause the thermal conditioning system (1) to execute the control method (2) according to any one of claims 1 to 10.

12. Computer-readable medium on which the computer program according to the preceding claim is recorded.

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