Method for controlling a thermal conditioning system

Abstract

The present invention relates to a method for controlling a thermal conditioning system (100) comprising: a heat transfer fluid circuit (20); a refrigerant circuit (10) having: an electric compressor (7); a first heat exchanger (1) configured to deliver a thermal power (Pw1) to a heat transfer fluid (F1); a first pressure reducer (31); a second heat exchanger (2); a bypass branch (B) for returning refrigerant at the outlet of the compressor (7) to the second exchanger (2) and to a second pressure reducer (32), the method comprising the steps of: (i) receiving a thermal power setpoint (C_Pw) of the thermal power to be delivered to at least one heat transfer fluid (F1); (ii) determining an electric power setpoint (C_Pw_el) of the electric power to be delivered to the compressor (7); (iv) determining a suction pressure setpoint (C_Pr_s) of the compressor (7); (vi) controlling the flow cross section of the second pressure reducer (32) so that the suction pressure (Ps) of the compressor (7) is equal to the determined suction pressure setpoint (C_Pr_s); (vii) controlling the flow cross section of the first pressure reducer (331) so that the refrigerant at the inlet of the compressor (7) is in a superheated vapor state.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of thermal conditioning systems. Such thermal conditioning systems can notably be installed on board of motor vehicles. If the vehicle has an electric drive train, these systems make it possible to thermally condition various components of the vehicle, such as the vehicle interior or an electrical energy storage battery. The heat exchanges are managed mainly by compression and expansion of a refrigerant fluid within a plurality of heat exchangers. BACKGROUND

[0002] Thermal conditioning systems generally use a refrigerant fluid circuit and a circuit for a heat transfer liquid used to exchange heat with the refrigerant fluid. Such systems are therefore said to be indirect. A compressor brings the refrigerant fluid to high pressure.

[0003] It is known to arrange in series in the refrigerant fluid circuit a first heat exchanger for heating an air flow intended for the vehicle interior, a second heat exchanger for heating an element of the drive train of the vehicle, such as an electrical energy storage battery, and a third heat exchanger for cooling this element of the drive train of the vehicle. Depending on the operating mode, it is thus made possible to supply heat to the element of the drive train of the vehicle to heat it, or to collect heat from this element in order to transfer it to, for example, the air flow intended for the vehicle interior, in order to heat the latter.

[0004] When the vehicle is started in a cold ambient temperature, it is desirable to ensure a rapid rise in the temperature of the vehicle interior in order to ensure good thermal comfort for the passengers. To this end, it is known to provide the refrigerant fluid circuit with a bypass branch which allows the refrigerant fluid leaving the compressor to reach the third exchanger without passing through the first or second exchanger. The flow of high-pressure refrigerant fluid at the outlet of the compressor is divided into a flow which circulates in the main loop and a flow which circulates in the bypass branch. After having passed through the third heat exchanger, all the refrigerant fluid flows to the inlet of the compressor. This particular thermodynamic cycle makes it possible to increase the flow rate of the refrigerant fluid circulating in the circuit, thereby increasing the amount of energy received by the refrigerant fluid when it is compressed. The temperature rise of the refrigerant fluid is thus accelerated.

[0005] This operating mode makes it possible to ensure an accelerated rise in the temperature of the vehicle interior, but generally poses difficulties for controlling the operation of the compressor and the respective fluid circulation in the main loop and in the bypass branch.

[0006] There is therefore a need for an optimized control method for such a thermal conditioning system. SUMMARY

[0007] To this end, the present invention proposes a method for controlling a thermal conditioning system, the thermal conditioning system comprising:

[0008] - a heat transfer liquid circuit configured to circulate a heat transfer liquid,

[0009] - a refrigerant fluid circuit having:

[0010] - a main loop comprising, in the flow direction of the refrigerant fluid, successively:

[0011] - a compressor configured to be driven by an electric motor, the compressor being configured to transform the refrigerant fluid from a suction pressure to a delivery pressure,

[0012] - a first heat exchanger configured to provide a heat power to a heat transfer fluid,

[0013] - a first expansion valve,

[0014] - a second heat exchanger arranged jointly on the refrigerant fluid circuit and on the heat transfer liquid circuit so as to receive a heat power (Pw2) from the heat transfer liquid,

[0015] - a first bypass branch allowing the refrigerant fluid at the outlet of the compressor to reach the second heat exchanger by bypassing the first exchanger and the first expansion valve, the first bypass branch comprising a second expansion valve,

[0016] The control method comprises the following steps:

[0017] (i) receiving a heat power setpoint of at least the heat power to be provided to the heat transfer fluid at the first exchanger,

[0018] (ii) determining an electric power setpoint of the electric power to be provided to the electric motor of the compressor, based on the received heat power setpoint of the heat power to be provided and based on the heat power received by the second exchanger,

[0019] (iii) determining a delivery pressure setpoint, based on the determined electric power setpoint and based on the maximum delivery pressure,

[0020] (iv) determining a suction pressure setpoint, based on the determined electric power setpoint and based on the determined delivery pressure setpoint,

[0021] (v) controlling the rotation speed of the electric motor of the compressor so that the electric power provided to the compressor is equal to the determined setpoint,

[0022] (vi) controlling the passage cross section of the second expansion valve so that the suction pressure of the compressor is equal to the determined suction pressure setpoint,

[0023] (vii) controlling the passage cross section of the first expansion valve so that the refrigerant fluid at the inlet of the compressor is in a superheated vapor state.

[0024] This control structure makes it possible to robustly control the amount of refrigerant fluid circulating in the refrigerant fluid circuit, as well as the distribution between the flow of this refrigerant fluid circulating in the main loop and passing through the first exchanger and the flow circulating in the first bypass branch and joining the flow of the main branch downstream of the first expansion valve.

[0025] The functions listed in the following paragraphs can be implemented independently of one another or in any technically feasible combination:

[0026] According to one exemplary embodiment, the thermal regulation system is a thermal regulation system for a motor vehicle.

[0027] According to one embodiment, in step (ii), the setpoint of the electric power to be provided to the electric motor of the compressor is equal to the setpoint of the total heating power received minus the heating power received by the second exchanger.

[0028] According to one embodiment, in step (iv), the intake pressure setpoint is determined on the basis of the electric power setpoint, on the basis of the determined delivery pressure setpoint and on the basis of a maximum allowed rotational speed of the compressor.

[0029] The maximum allowed rotational speed can depend on the operating conditions. In particular, the maximum allowed rotational speed can depend on the speed of forward travel of the vehicle. In this way, the maximum allowed speed when the vehicle is moving can be higher than the maximum allowed speed when the vehicle is stopped.

[0030] The maximum delivery pressure can be a constant value, for example 27 bar.

[0031] The maximum delivery pressure can correspond to the maximum allowed pressure ensuring the long-term reliability of the compressor. The use of a constant value makes it possible to simplify the control method.

[0032] According to one embodiment of the method, the setpoint of the electric power to be provided to the electric motor of the compressor is for example equal to the total heating power setpoint received.

[0033] According to a variant, the setpoint of the electric power to be provided to the electric motor of the compressor can be equal to the total heating power setpoint received divided by the adiabatic efficiency of the compressor.

[0034] The electric power setpoint can thus be calculated more precisely.

[0035] According to one embodiment of the method, the passage cross section of the first expansion valve is controlled by a proportional-integral controller.

[0036] Similarly, the passage cross section of the second expansion valve can be controlled by a proportional-integral controller.

[0037] This type of controller ensures robust control while remaining easy to program and fine-tune.

[0038] According to one embodiment of the method, the control of the passage cross section of the first expansion valve and the control of the passage cross section of the second expansion valve are configured so that:

[0039] - an increase in the passage cross section of the first expansion valve results in a decrease in the passage cross section of the second expansion valve,

[0040] - an increase in the passage cross section of the second expansion valve results in an increase in the passage cross section of the first expansion valve.

[0041] The coupling between the correction of the passage cross section of the first expansion valve and the correction of the passage cross section of the second expansion valve makes it possible to improve the control stability.

[0042] According to one embodiment of the method, in which the main loop of the refrigerant fluid circuit comprises a third expansion valve arranged downstream of the compressor and upstream of the first heat exchanger, the method comprises the following steps:

[0043] (viii) controlling the passage cross section of the refrigerant fluid in the third expansion valve so that the delivery pressure is equal to the determined delivery pressure setpoint.

[0044] To this end, step (viii) comprises the following substep: determining the delivery pressure (Pr_d).

[0045] Ensuring partial expansion of the refrigerant fluid in the third expansion valve forces the compressor to compress the refrigerant fluid to a value higher than the condensation pressure in the first exchanger. The thermal power received by the refrigerant fluid is thus increased and this makes it possible to accelerate the temperature rise of the thermoregulation system.

[0046] According to one embodiment, the method comprises the following steps:

[0047] (vii1) determining the degree of superheat of the refrigerant fluid at the inlet of the compressor,

[0048] (vii2) controlling the passage cross section of the first expansion valve so that the degree of superheat of the refrigerant fluid at the inlet of the compressor is equal to a setpoint value.

[0049] The degree of superheat setpoint at the inlet of the compressor is chosen to ensure that the refrigerant sucked in by the compressor is entirely in gaseous form. This ensures the reliability of the compressor.

[0050] The degree of superheat setpoint value of the refrigerant fluid at the inlet of the compressor is for example between 5°C and 15°C.

[0051] According to one embodiment, the method comprises the following steps:

[0052] (vii1) determining the degree of superheat of the refrigerant fluid at the outlet of the compressor,

[0053] (vii2) controlling the passage cross section of the first expansion valve so that the degree of superheat of the refrigerant fluid at the outlet of the compressor is equal to a setpoint value.

[0054] Controlling the degree of superheat setpoint at the outlet of the compressor is another way of ensuring that the refrigerant sucked in by the compressor is substantially entirely in gaseous form. This ensures the reliability of the compressor.

[0055] The degree of superheat setpoint value of the refrigerant fluid at the outlet of the compressor is between 15°C and 35°C.

[0056] According to one embodiment of the method, wherein the main loop of the thermoregulation system comprises, downstream of the first heat exchanger and upstream of the first expansion device, a third heat exchanger, which is jointly arranged on the refrigerant fluid circuit and on the heat transfer liquid circuit so as to be able to exchange heat between the refrigerant fluid and the heat transfer liquid, the third heat exchanger being configured to supply a heat power to the heat transfer liquid, wherein, in step (i),

[0057] The heat power setpoint of the heat power to be supplied is the total heat power, which is the sum of the heat power to be supplied to the heat transfer fluid at the first exchanger and of the heat power to be supplied to the heat transfer liquid at the third exchanger.

[0058] According to one exemplary embodiment of the method, the heat transfer fluid is an air flow inside the motor vehicle.

[0059] According to one exemplary embodiment of the method, the heat transfer fluid is a heat transfer liquid configured to circulate in a fifth heat exchanger, the fifth heat exchanger being configured to exchange heat with an air flow inside the vehicle.

[0060] According to one embodiment of the method, the second heat exchanger is thermally coupled to an element of the vehicle drive train via the heat transfer liquid in the heat transfer liquid circuit.

[0061] The second heat exchanger thus makes it possible to absorb heat from an element of the drive train of the vehicle, to keep its temperature within an acceptable range, or to transfer the absorbed heat to another component.

[0062] According to one embodiment of the method, the third heat exchanger is thermally coupled to an element of the drive train of the vehicle via the heat transfer liquid in the heat transfer liquid circuit.

[0063] The third heat exchanger thus makes it possible to supply a heat power to an element of the drive train of the vehicle, that is to say to heat this element to increase its temperature.

[0064] The element of the electric drive train comprises, for example, an electric traction motor of the vehicle.

[0065] In a variant or additionally, the elements of the electric drive train comprise an electronic module for operating an electric traction motor of the vehicle.

[0066] In another variant or additionally, the elements of the electric drive train comprise an electric energy storage battery.

[0067] The application also relates to a thermal conditioning system comprising:

[0068] - a heat transfer fluid circuit configured to circulate a heat transfer fluid,

[0069] - a refrigerant fluid circuit having:

[0070] - a main loop comprising, in the flow direction of the refrigerant fluid, in succession:

[0071] - a compressor configured to be driven by an electric motor, the compressor being configured to transform the refrigerant fluid from an intake pressure to a delivery pressure,

[0072] - a first heat exchanger configured to provide a thermal power to the heat transfer fluid,

[0073] - a first expansion valve,

[0074] - a second heat exchanger jointly arranged on the refrigerant fluid circuit and on the heat transfer fluid circuit so as to receive a thermal power from the heat transfer fluid,

[0075] - a first bypass branch allowing the refrigerant fluid at the outlet of the compressor to reach the second heat exchanger by bypassing the first exchanger and the first expansion valve, the first bypass branch comprising a second expansion valve,

[0076] - an electronic control unit configured to implement the control method described above.

[0077] According to one embodiment of the thermal conditioning system, the refrigerant fluid circuit comprises a second bypass branch arranged in parallel with the first expansion valve and the second heat exchanger, the second bypass branch comprising a fourth expansion valve and a fourth heat exchanger.

[0078] For example, the fourth heat exchanger is configured to exchange heat with an air flow inside the vehicle.

[0079] According to one aspect of the thermal conditioning system, the main loop of refrigerant fluid comprises a refrigerant fluid accumulation device arranged downstream of the first exchanger and upstream of the first expansion valve.

[0080] In one embodiment, the main loop of refrigerant fluid comprises a refrigerant fluid accumulation device arranged downstream of the first exchanger and upstream of the first expansion valve. In one embodiment, the main loop of refrigerant fluid comprises a first exchanger and a third exchanger, the refrigerant fluid accumulation device being arranged downstream of the third exchanger and upstream of the first expansion valve.

[0081] According to one embodiment of the thermoregulation system, the main loop of refrigerant fluid comprises an internal exchanger configured to enable heat exchange between high pressure refrigerant fluid downstream of the third heat exchanger and upstream of the first expansion valve and low pressure refrigerant fluid downstream of the second exchanger and upstream of the compressor.

[0082] According to one aspect of the thermoregulation system, it comprises a first bypass branch fluidically connecting a first connection point arranged on the main loop downstream of the compressor and upstream of the first exchanger to a second connection point arranged on the main loop downstream of the first expansion valve and upstream of the second exchanger, the first bypass branch having a second expansion device.

[0083] According to one embodiment, the thermoregulation system comprises a second bypass branch fluidically connecting a third connection point arranged on the main loop downstream of the third exchanger and upstream of the first expansion valve to a fourth connection point arranged on the main loop downstream of the second exchanger and upstream of the compressor, the second bypass branch having a fourth expansion device arranged upstream of the fourth heat exchanger. BRIEF DESCRIPTION OF DRAWINGS

[0084] Further features, details and advantages will become apparent from reading the following detailed description and from studying the appended drawings, in which:

[0085] Figure 1 is a schematic view of a thermoregulation system according to a first embodiment in which the control method according to the application is implemented,

[0086] Figure 2 is a schematic view of a thermoregulation system according to a second embodiment in which the control method according to the application is implemented,

[0087] Figure 3 is a schematic view of a variant of the thermoregulation system in Figure 2

[0088] Figure 4 is a schematic view of another variant of the thermoregulation system in Figure 2

[0089] Figure 5 is a thermodynamic diagram schematically showing the state of the refrigerant fluid when implementing the control method,

[0090] Figure 6 is a curve illustrating the operation of the control method,

[0091] Figure 7 is a block diagram illustrating the various steps of the method according to the application. DETAILED DESCRIPTION

[0092] ​​For the drawings to be easier to read, the various elements are not necessarily shown to scale. In these drawings, identical elements have identical reference designations. Certain elements or parameters can be indexed, that is to say designated, for example, as first element or second element, or first parameter and second parameter, etc. This indexing is intended to distinguish between similar but non-identical elements or parameters. This indexing does not imply that one element or parameter is preferred over another, and the names can be interchanged.

[0093] In the following description, the expression "a first element is upstream of a second element" means that the first element is located before the second element with respect to the direction of circulation or progression of the fluid. Similarly, the expression "a first element is downstream of a second element" means that the first element is located after the second element with respect to the direction of circulation or progression of the fluid in question. In the case of a refrigerant fluid circuit, the expression "a first element is upstream of a second element" means that the refrigerant fluid passes successively through the first element, then through the second element, without passing through the compression device. In other words, the refrigerant fluid leaves the compression device, possibly passes through one or more elements, then passes through the first element, then passes through the second element, then returns to the compression device, in some cases having passed through additional elements.

[0094] The expression "a second element is located between a first element and a third element" means that the shortest path from the first element to the third element passes through the second element. This does not exclude the presence of other elements in the subsystem when a subsystem is designated with a given element.

[0095] In the described thermal regulation system 100, the electronic control unit 50 receives information from various sensors (not shown), in particular measuring physical properties of the refrigerant fluid at various points of the circuit. The electronic control unit also receives setpoints issued by the vehicle occupants, for example a desired temperature inside the vehicle. The electronic control unit implements control laws for operating the various actuators in order to control the thermal regulation system 100 so as to achieve the received setpoints. The electronic control unit 50 in particular implements the method according to the invention.

[0096] The compression device 7 can be an electric compressor, that is to say a compressor whose moving parts are driven by an electric motor 6. The compression device 7 has a suction side for low-pressure refrigerant fluid, also called inlet of the compression device 7a, and a delivery side for high-pressure refrigerant fluid, also called outlet of the compression device 7b. The internal moving parts of the compressor 7 bring the refrigerant fluid from a low pressure or suction temperature Pr_s at the inlet side 7a to a high pressure or delivery pressure Pr_d at the outlet side 7b. After expansion in one or more expansion devices, the refrigerant fluid returns to the inlet 7a of the compressor 7 and starts a new thermodynamic cycle again.

[0097] The refrigerant fluid circuit 10 forms a closed circuit in which the refrigerant fluid can circulate. When the refrigerant fluid circuit 10 is in a nominal operating condition, i.e. an operating condition without defects or leaks, the refrigerant fluid circuit 10 is sealed. Each connection point of the circuit 10 allows the refrigerant fluid to pass into one or the other of the circuit portions which converge at this connection point. By adjusting the opening or closing of the shut-off valves, check valves or expansion devices of each branch, the refrigerant fluid is distributed between the circuit portions which converge at the connection points. In other words, each connection point is a means for redirecting the refrigerant fluid arriving at this connection point. The shut-off valves and check valves thus make it possible to selectively direct the refrigerant fluid into the various branches of the refrigerant circuit in order to provide different operating modes, which will be described later.

[0098] In this case, the refrigerant fluid used by the refrigerant fluid circuit 1 is a chemical fluid, such as R1234yf. Other refrigerant fluids can also be used, for example R134a, R290 or R744.

[0099] The internal air flow Fi is understood to be the flow of air inside the motor vehicle. This internal air flow can circulate in an HVAC (heating, ventilation and / or air conditioning) device. This device is not shown in the various figures. If necessary, an engine fan (not shown) can be started in order to increase the flow rate of the internal air flow Fi.

[0100] Figure 1 A thermal regulation system 100 is shown, comprising:

[0101] - a heat transfer liquid circuit 20 configured to circulate a heat transfer liquid,

[0102] - a refrigerant fluid circuit 10 having:

[0103] - a main loop A comprising, in the direction of flow of the refrigerant fluid, in this order:

[0104] - a compressor 7 configured to be driven by an electric motor 6, the compressor 7 being configured to bring the refrigerant fluid from a suction pressure Pr_s to a delivery pressure Pr_d,

[0105] - a first heat exchanger 1 configured to provide a thermal power Pw1 to the heat transfer fluid F1,

[0106] - a first expansion valve 31,

[0107] - a second heat exchanger 2 arranged jointly on the refrigerant fluid circuit 10 and on said heat transfer liquid circuit 20 so as to receive a thermal power Pw2 from the heat transfer liquid,

[0108] - a first bypass branch B allowing the refrigerant fluid at the outlet of the compressor 7 to pass by the first exchanger 1 and the first expansion valve 31 to reach the second exchanger 2, the first bypass branch B comprising a second expansion valve 32,

[0109] - an electronic control unit 50 configured to implement a control method which will be described in detail below.

[0110] The first heat exchanger 1 is configured to exchange heat with a heat transfer fluid Fl. The first heat exchanger 1 can be used as a condenser. The condensation heat of the refrigerant fluid is transferred to the heat transfer fluid Fl. A thermal power Pwl is thus provided to the heat transfer fluid Fl.

[0111] The second heat exchanger 2 is a double fluid exchanger. In other words, the second heat exchanger 2 comprises a first compartment through which the refrigerant fluid passes and a second compartment through which a heat transfer liquid passes. The two compartments are sealed and can exchange heat. The double fluid exchanger comprises a refrigerant fluid inlet and outlet, and a heat transfer liquid inlet and outlet. Inside the second exchanger 2, the refrigerant fluid can thus receive a thermal power Pw2 from the heat transfer liquid. A heating element 22, for example an electric heating element, can be arranged on the heat transfer liquid circuit 20 in order to heat the heat transfer liquid under certain operating conditions. Thus, a thermal power Pw2 is transferred from the heat transfer liquid to the refrigerant fluid inside the second exchanger 2. The heating element 22 is optional.

[0112] Each expansion valve of the thermal regulation system 100 is a device for expanding the refrigerant fluid. Each expansion valve is configured to vary the refrigerant fluid passage cross section. Each expansion valve comprises a refrigerant fluid inlet and a refrigerant fluid outlet. The outlet and the inlet are fluidly connected by a duct. A movable shutter makes it possible to control the passage cross section of the duct, that is to say to provide the passage surface area of the refrigerant fluid. The expansion valve is for example an electronic expansion valve, that is to say the movable shutter is actuated by an electric motor commanded by an electronic control module. The position of the movable shutter can be controlled in closed loop, that is to say the position of the movable shutter is measured and regulated in real time in order to obtain a position set point. The refrigerant fluid passage cross section can be continuously adjusted between a closed position and a maximum open position. The electronic control module of each expansion valve can be integrated in the corresponding expansion valve. According to a variant, the electronic control unit 50 can also command and control each expansion valve.

[0113] The first expansion valve 31 is configured to vary the refrigerant fluid passage cross section in the circuit portion located downstream of the first exchanger 1 and upstream of the second connection point 12. The second expansion valve 32 is configured to vary the refrigerant fluid passage cross section in the first bypass branch B.

[0114] According to one exemplary embodiment, the thermal regulation system 100 is a thermal regulation system for a motor vehicle.

[0115] InFigure 1 In the embodiment of Fig. 1, the heat transfer fluid F1 is an air flow Fi inside a motor vehicle. The first heat exchanger 1 is arranged in a heating, ventilation and / or air conditioning device.

[0116] In this case, the second heat exchanger 2 is thermally coupled to an element 25 of an electric drive train of the vehicle. The thermal coupling is achieved via the heat transfer liquid in the heat transfer liquid circuit 20. To this end, the heat transfer liquid circulating in the heat transfer liquid circuit 20 exchanges heat with the element 25 of the drive train of the vehicle.

[0117] The second heat exchanger 2 thus makes it possible to absorb heat from the element 25 of the drive train of the vehicle. The heat emitted by the operation of the element 25 is transferred to the heat transfer liquid in the circuit 20. Depending on the operating conditions, the temperature of the element 25 can be kept within an acceptable range, or the absorbed heat can be transferred to another component in order to heat it.

[0118] The element 25 of the electric drive train comprises, for example, an electric traction motor of the vehicle. In a variant or additionally, the element 25 of the electric drive train comprises an electrical energy storage battery. In another variant or additionally, the element 25 of the electric drive train comprises an electronic module for operating an electric traction motor of the vehicle.

[0119] The first bypass branch B fluidically connects the first connection point 11, arranged on the main loop A, downstream of the compressor 7 and upstream of the first exchanger 1, to the second connection point 12, arranged on the main loop A, downstream of the first expansion valve 31 and upstream of the second exchanger 2. It will thus be understood that the first bypass branch B establishes fluid communication between the first connection point 11 and the second connection point 12. The first bypass branch B has a second expansion device 32.

[0120] The main loop A of refrigerant fluid comprises a refrigerant fluid accumulation device 8 arranged downstream of the first exchanger 1 and upstream of the first expansion valve 31. The refrigerant fluid accumulation device 8 is a receiver dryer.

[0121] The application proposes a method for controlling a thermal conditioning system 100 comprising:

[0122] - a heat transfer liquid circuit 20 configured to circulate a heat transfer liquid,

[0123] - a refrigerant fluid circuit 10 having:

[0124] - a main loop A comprising, in the direction of flow of the refrigerant fluid, in this order:

[0125] - a compressor 7 configured to be driven by an electric motor 6, the compressor 7 being configured to bring the refrigerant fluid from a suction pressure Pr_s to a delivery pressure Pr_d,

[0126] - a first heat exchanger 1 configured to provide a thermal power Pw1 to a heat transfer fluid Fl,

[0127] - a first expansion valve 31,

[0128] - a second heat exchanger 2, arranged jointly on the refrigerant fluid circuit 10 and on the heat transfer liquid circuit 20, so as to be able to exchange heat between the refrigerant fluid and the heat transfer liquid,

[0129] - a first bypass branch B allowing the refrigerant fluid at the outlet of the compressor 7 to reach the second heat exchanger 2 by bypassing the first exchanger 1 and the first expansion valve 31, the first bypass branch B having a second expansion valve 32,

[0130] The control method comprises the following steps:

[0131] (i) receiving a thermal power setpoint C_Pw of at least the thermal power to be provided to the heat transfer fluid Fl at the first exchanger 1,

[0132] (ii) determining, on the basis of the received thermal power setpoint C_Pw of the thermal power to be provided and of the thermal power Pw2 received by the second exchanger 2, an electric power setpoint C_Pw_el of the electric power to be provided to the electric motor 6 of the compressor 7,

[0133] (iii) determining, on the basis of the determined electric power setpoint C_Pw_el and on the basis of a maximum delivery pressure Pr_d_max, a delivery pressure setpoint C_Pr_d,

[0134] (iv) determining, on the basis of the determined electric power setpoint C_Pw_el and on the basis of the determined delivery pressure setpoint C_Pr_d, a suction pressure setpoint C_Pr_s,

[0135] (v) controlling the rotational speed N of the electric motor 6 of the compressor 7 so that the electric power Pw_el provided to the compressor 7 is equal to the determined setpoint C_Pw_el,

[0136] (vi) controlling the passage cross section of the second expansion valve 32 so that the suction pressure Ps of the compressor 7 is equal to the determined suction pressure setpoint C_Pr_s,

[0137] (vii) controlling the passage cross section of the first expansion valve 31 so that the refrigerant fluid at the inlet of the compressor 7 is in a superheated vapor state.

[0138] This control structure makes it possible to robustly control the amount of refrigerant fluid circulating in the refrigerant fluid circuit, as well as the distribution between the flow circulating in the main loop and passing through the first exchanger and the flow circulating in the first bypass branch and merging with the main branch downstream of the first expansion valve.

[0139] In step (ii), the electric power setpoint C_Pw_el of the electric power to be provided to the electric motor 6 of the compressor 7 is equal to the received setpoint C_Pw of the thermal power to be provided minus the thermal power Pw2 received by the second exchanger 2.

[0140] In particular: C_Pw_el = C_PW - PW2

[0141] In step (iv), the suction pressure setpoint C_Pr_s is determined on the basis of the electric power setpoint C_Pw_el, on the basis of the determined delivery pressure setpoint C_Pr_d and on the basis of a maximum allowed rotational speed of the compressor 7.

[0142] The maximum allowed rotational speed depends on the speed of forward travel of the vehicle. Thereby, the maximum allowed speed can be higher when the vehicle is travelling than when the vehicle is stopped, because the background noise is higher when the vehicle is travelling. The maximum allowed rotational speed can for example be mapped as a function of the speed of the vehicle, that is to say that the value of the maximum allowed rotational speed is looked up in a table by inputting the speed of the vehicle.

[0143] The maximum delivery pressure Pr_d_Max can be a constant value, for example 27 bar.

[0144] The maximum delivery pressure Pr_d_Max can correspond to a maximum allowed pressure ensuring long-term reliability of the compressor 7. The use of a constant value makes it possible to simplify the control method.

[0145] According to a variant, the maximum delivery pressure Pr_d_Max can be a tabulated value, for example a value based on a list of speeds of forward travel of the vehicle. A tabulated value is understood to mean that the value of the maximum delivery pressure can be looked up in a table, also called a map, various output values being assigned according to the input values of the table.

[0146] The maximum delivery pressure Pr_d_Max can therefore depend on the operating conditions. For example, the maximum delivery pressure Pr_d_Max can depend on the speed of forward travel of the vehicle. Thus, the maximum pressure provided by the compressor 7 can be limited when the vehicle is stopped, to limit the noise generated, which can be particularly annoying in the absence of noise generated by the vehicle when it is travelling.

[0147] According to one embodiment of the method, the electric power setpoint E_Pw_el of the electric power to be provided to the electric motor 6 of the compressor 7 is for example equal to the received total heating power setpoint. In other words, the efficiency of the compressor 7 is assumed to be ideal.

[0148] According to a variant, the electric power setpoint C_Pw_el of the electric power to be supplied to the electric motor 6 of the compressor 7 can be equal to the received total heating power setpoint divided by the adiabatic efficiency of the compressor 7. In this case, the electric power setpoint is thus calculated more precisely, since the efficiency is no longer assumed to be ideal. The efficiency can be characterized under various operating conditions and for example mapped.

[0149] The passage cross section of the first expansion valve 31 is for example controlled by a proportional integral controller. Similarly, the passage cross section of the second expansion valve 32 can be controlled by a proportional integral controller. This type of controller ensures robust control while still being easy to program and fine-tune.

[0150] According to one embodiment of the method, the control of the passage cross section of the first expansion valve 31 and the control of the passage cross section of the second expansion valve 32 are configured so that:

[0151] - an increase in the passage cross section of the first expansion valve 31 leads to a decrease in the passage cross section of the second expansion valve 32,

[0152] - an increase in the passage cross section of the second expansion valve 32 leads to an increase in the passage cross section of the first expansion valve 31.

[0153] The coupling between the correction made to the passage cross section of the first expansion valve 31 and the correction made to the passage cross section of the second expansion valve 32 makes it possible to improve the stability of the control. The gain associated with a decrease in the passage cross section of the second expansion valve 32 is for example equal to half the gain associated with an increase in the passage cross section of the first expansion valve 31. Thus, when the controller opens the first expansion valve 31 by a certain amount, it simultaneously closes the second expansion valve 32 by a value equal to half of this amount.

[0154] According to the example described here, the main loop A of the refrigerant fluid circuit 10 comprises a third expansion valve 33 arranged downstream of the compressor 7 and upstream of the first heat exchanger 1, the method comprising the following steps:

[0155] (viii) controlling the passage cross section of the refrigerant fluid in the third expansion valve 33 so that the delivery pressure Pr_d is equal to the determined delivery pressure setpoint C_Pr_d.

[0156] Step (viii) thus comprises the following sub-step: determining the delivery pressure Pr_d.

[0157] Figure 5 The thermodynamic states of the refrigerant fluid during a thermodynamic cycle are illustrated. The values on the abscissa axis are the enthalpy of the refrigerant fluid. The values on the ordinate axis are the pressure of the refrigerant fluid, on a logarithmic scale. The curve S is the saturation characteristic curve of the refrigerant fluid used. The area illustrated between the saturation curve S and the abscissa axis corresponds to the two-phase region of the refrigerant fluid.

[0158] Point A7a represents the state of the refrigerant fluid at the inlet of compressor 7. The pressure of the refrigerant fluid at this point is equal to the intake pressure Pr_s. Point A7b represents the state of the refrigerant fluid at the outlet of compressor 7. The pressure at this point is equal to the delivery pressure Pr_d. Point A1a represents the state of the refrigerant fluid at the inlet 1a of the first exchanger 1. The third expansion valve 33 causes partial expansion of the refrigerant fluid, making the pressure of the refrigerant fluid in the first exchanger 1 less than the delivery pressure Pr_d of compressor 7.

[0159] Ensuring partial expansion of the refrigerant fluid in the third expansion valve 33 forces the compressor 7 to compress the refrigerant fluid to a value higher than the condensing pressure in the first exchanger 1. This increases the heat power received by the refrigerant fluid during compression, thus accelerating the temperature rise of the thermal regulation system 100. Furthermore, using the highest possible delivery pressure allows for a reduction in the compressor 7's speed, thereby lowering the level of operating noise.

[0160] At the outlet of compressor 7, the high-pressure refrigerant fluid flow is divided between a first flow and a second flow. The first flow flows in the main loop A and through the first exchanger 1, while the second flow flows in the first bypass branch B. The division of the two flows is performed at the first connection point 11. The refrigerant fluid flowing in the main loop A and partially expanded by the third expansion valve 33 condenses in the first exchanger 1 by releasing heat to the heat transfer fluid F1. Indicator Q1 indicates the amount of heat transferred, and point A8 characterizes the state of the refrigerant fluid at the outlet of the accumulation device 8. The refrigerant fluid leaving the first exchanger 1 then expands at the first expansion valve 31. Point A31a characterizes the state of the refrigerant fluid at the inlet of the first expansion valve 31, and point A31b characterizes the state at the outlet of the first expansion valve 31, i.e., the state after expansion. At this point, the refrigerant fluid is two-phase, mainly in liquid form.

[0161] The flow in the first bypass branch B undergoes expansion at the second expansion valve 32. Point A32b represents the thermodynamic state of the refrigerant fluid at the outlet of the second expansion valve 32. At this point in the cycle, the refrigerant fluid is in a superheated vapor state. This superheated vapor flow flowing in the first bypass branch B mixes with the two-phase refrigerant fluid flow flowing in the main loop A at the second connection point 12 and reaches the inlet 2a of the second exchanger 2. Point A2a shows the state of the mixing point. The flow of superheated vapor is controlled so that the resulting mixture is entirely in gaseous form, that is, in superheated vapor form. This ensures the reliability of the compressor 7, as there is no risk of the compressor 7 receiving liquid refrigerant. Point A2b represents the state of the refrigerant fluid at the outlet of the second exchanger 2. Heat exchange at the second exchanger 2 is negligible. Figure 5By way of example, the water head loss generated by the second exchanger 2 has been exaggerated in order to make the figure easier to read. The refrigerant fluid leaving the second exchanger 2 reaches the inlet of the compressor 7, characterized by the point A7a. The thermodynamic cycle is thus completed.

[0162] Figure 6 The relationship between the suction pressure Pr_s at the inlet of the compressor and the electric power Pw_el supplied to the compressor is shown for a given fixed delivery pressure Pr_d, for example 25 bar. The curve N1 corresponds to a constant speed N of the compressor, equal to 5000 rpm in this case. The curve N2 corresponds to a speed greater than N1, equal to 6000 rpm in this case, and the curve N3 corresponds to a constant speed greater than N2, equal to 7000 rpm in this case. At constant speed, the electric power consumed by the compressor is an increasing function of the suction pressure Pr_s. For a given suction pressure, the electric power consumed by the electric motor 6 driving the compressor 7 increases with the speed. Such a family of curves is determined for the entire speed range of the compressor 7, for the entire range of allowed suction pressures and for the entire range of allowed delivery pressures. The family of curves allows the control method to determine the suction pressure, the delivery pressure and the speed, which makes it possible to obtain a setpoint of the electric power consumed by the compressor and, from this, a setpoint of the thermal power to be released.

[0163] According to one embodiment, the method comprises the following steps:

[0164] (vii1) determining the superheat Sh of the refrigerant fluid at the inlet of the compressor 7,

[0165] (vii2) controlling the passage cross section of the first expansion valve 31 so that the superheat Sh of the refrigerant fluid at the inlet of the compressor 7 is equal to a setpoint value C_Sh.

[0166] The setpoint C_Sh of the superheat at the inlet of the compressor 7 is chosen so as to ensure that the refrigerant sucked in by the compressor 7 is entirely in gaseous form, thus ensuring the reliability of the compressor 7. The control of the passage cross section of the second expansion valve 32 makes it possible to control the flow of superheated vapour circulating in the first bypass branch B and, consequently, the composition of the mixture illustrated by the point A2a.

[0167] The setpoint value C_Sh of the superheat of the refrigerant fluid at the inlet of the compressor 7 is for example between 5°C and 15°C.

[0168] By definition, the superheat at the inlet of the compressor 7 is equal to the temperature of the refrigerant fluid at the inlet of the compressor 7 minus the condensation temperature value of the refrigerant fluid, which corresponds to the pressure of the refrigerant fluid at the inlet of the compressor 7, i.e. the suction pressure Pr_s. The temperature of the refrigerant fluid is for example measured by a temperature sensor whose sensing element is in contact with the refrigerant fluid. Similarly, the pressure of the refrigerant fluid is for example measured by a pressure sensor whose sensing element is in contact with the refrigerant fluid.

[0169] According to another embodiment, the method comprises the steps of:

[0170] (vii1') determining the superheat Dsh of the refrigerant fluid at the outlet of the compressor 7,

[0171] (vii2') controlling the passage cross section of the first expansion valve 31 so that the superheat of the refrigerant fluid at the outlet of the compressor 7 is equal to the setpoint value C_Dsh.

[0172] Controlling the superheat setpoint C_Dsh at the outlet of the compressor 7 is another way to ensure that the refrigerant sucked by the compressor 7 is entirely in gaseous form, thus ensuring the reliability of the compressor 7.

[0173] The setpoint value C_Dsh of the superheat of the refrigerant fluid at the outlet of the compressor 7 is comprised between 15°C and 35°C.

[0174] The superheat Dsh at the outlet of the compressor 7 is equal to the measured temperature of the refrigerant fluid at the outlet of the compressor 7 minus the condensation temperature value of the refrigerant fluid, which corresponds to the pressure of the refrigerant fluid at the outlet of the compressor 7, i.e. the delivery pressure Pr_d.

[0175] Figure 2 A second embodiment of the thermoregulation system 100 is shown, in which the control method is implemented. In this second embodiment, the main circuit A of the thermoregulation system 100 comprises a third heat exchanger 3 downstream of the first heat exchanger 1 and upstream of the first expansion device 31, which is arranged jointly on the refrigerant fluid circuit 10 and on the heat transfer liquid circuit 20 so as to be able to exchange heat between the refrigerant fluid and the heat transfer liquid. The third heat exchanger 3 is configured to provide a heat power Pw3 to the heat transfer liquid.

[0176] In step (i) of the control method, the heat power setpoint Pw of the heat power to be provided is the total heat power Pw_tot, which is the sum of the heat power Pw1 to be provided to the heat transfer fluid F1 at the first exchanger 1 and of the heat power Pw3 to be provided to the heat transfer liquid at the third exchanger 3.

[0177] Although in the first embodiment the refrigerant fluid provides thermal power to the first heat transfer fluid F1 only at the first exchanger 1, in the second embodiment the refrigerant fluid also provides thermal power to the heat transfer liquid in the circuit 20 also at the third exchanger 3. The thermal power setpoint Pw of the thermal power to be provided corresponds to the total power to be provided, i.e. the thermal power provided by the first exchanger 1 plus the thermal power provided by the third exchanger 3.

[0178] The third heat exchanger 3 is a double-fluid exchanger. It can have a similar structure as the second exchanger 2. Its exchanger is for example a plate exchanger.

[0179] In other words, in this second embodiment, the main loop A comprises in sequence, in series: the compressor 7, the first connection point 11, the third expansion valve 33, the first exchanger 1, the third exchanger 3, the accumulation device 8, the first expansion valve 31, the second connection point 12, the second exchanger 2 and the circuit portion extending between the outlet 2b of the second exchanger 2 and the inlet 7a of the compressor 7. The condensation of the high-pressure refrigerant fluid occurs partly in the first exchanger 1 and partly in the second exchanger 2. Thus, the first heat transfer fluid F1 can be heated at the first exchanger 1 and the heat transfer liquid in the circuit 20 can be heated at the third exchanger 3. The total thermal power Pw to be provided is distributed between the thermal power Pw1 provided by the first exchanger 1 to the first heat transfer fluid F1 and the thermal power Pw3 provided by the third exchanger 3 to the heat transfer liquid circulating in the heat transfer liquid circuit 20. The distribution between the thermal power Pw1 and the thermal power Pw3 can be achieved by adjusting control parameters which will not be detailed again.

[0180] In this embodiment, the first bypass branch B allows the refrigerant fluid at the outlet of the compressor 7 to reach the second exchanger 2 by bypassing the first exchanger 1, the third exchanger 3 and the first expansion valve 31. In particular, the first bypass branch B connects a point arranged upstream of the third expansion valve 33 to a point arranged downstream of the first expansion valve 31.

[0181] In this embodiment, the main loop A of the refrigerant fluid comprises a refrigerant fluid accumulation device 8 arranged downstream of the first exchanger 3 and upstream of the first expansion valve 31. In other words, the liquid accumulator 8 is arranged between the third exchanger 3 and the first expansion valve 31.

[0182] The third heat exchanger 3 is thermally coupled to an element 25 of the powertrain of the vehicle via the heat transfer liquid in the heat transfer liquid circuit 20.

[0183] The third heat exchanger 3 thus makes it possible to supply heat power to an element 25 of the driveline of the vehicle, that is to say to heat this element 25. The second exchanger 2 is able to receive heat power from the element 25 in order to cool it or to collect energy. The heat transfer fluid circuit 20 is not shown in detail and is shown in dotted lines at the third exchanger 3 and at the second exchanger 2. In order to make the representation simpler and to avoid the lines of the various circuits crossing each other, the circuit 20 is shown in two separate parts.

[0184] Figure 3 A variant of the embodiment in Figure 2 is shown. In this variant, the heat transfer fluid F1 is a heat transfer liquid configured to circulate in a fifth heat exchanger 5 configured to exchange heat with an air flow Fi of the interior of the vehicle.

[0185] The fifth heat exchanger 5 is arranged on a second heat transfer liquid circuit 21. The interior of the vehicle is indirectly heated because the condensation heat of the refrigerant fluid is first transferred to the heat transfer liquid in the circuit 21, then the heat of the heat transfer liquid is transferred to the interior air flow Fi at the fifth exchanger 5. A pump (not shown) can circulate the heat transfer liquid in the circuit 21. The other exchangers have the same role as in the first embodiment in Figure 2 . The heat transfer liquid circuit 21 for heating the interior of the vehicle and the heat transfer liquid circuit 20 for thermally coupling to the element 25 of the driveline are separate, that is to say they are not connected.

[0186] In the second embodiment and its variant, the refrigerant fluid circuit 10 comprises a second bypass branch C arranged in parallel with the first expansion valve 31 and the second heat exchanger 2, the second bypass branch C comprising a fourth expansion valve 34 and a fourth heat exchanger 4.

[0187] The second bypass branch C fluidically connects a third connection point 13 arranged on the main loop A downstream of the third exchanger 3 and upstream of the first expansion valve 31 to a fourth connection point 14 arranged on the main loop A downstream of the second exchanger 2 and upstream of the compressor 7. The second bypass branch C has a fourth expansion device 34 arranged upstream of the fourth heat exchanger 4.

[0188] The fourth heat exchanger 4 is configured to exchange heat with an air flow Fi of the interior of the vehicle. The fourth heat exchanger 4 is arranged in a heating, ventilation and / or air conditioning device.

[0189] In the embodiment in Figure 1 and in the embodiment of Figure 2 and Figure 4 , in which the first exchanger 1 is arranged in a heating, ventilation and / or air conditioning device, the first exchanger 1 is arranged downstream of the fourth exchanger 4 in the flow direction of the interior air flow Fi. In Figure 3In the variant shown, in a heating, ventilation and / or air conditioning device, the fifth exchanger 5 is arranged downstream of the fourth exchanger 4. The fourth exchanger 4 makes it possible to ensure cooling of the vehicle interior in order to keep the vehicle occupants thermally comfortable by a warm environment.

[0190] Figure 4 Another variant of the embodiment of the thermal conditioning system 100 is shown in Figure 2 The main circuit A of refrigerant fluid comprises an internal exchanger 9 configured to make it possible to exchange heat between high-pressure refrigerant fluid downstream of the third heat exchanger 3 and upstream of the first expansion valve 31 and low-pressure refrigerant fluid downstream of the second exchanger 2 and upstream of the compressor 7.

[0191] The internal heat exchanger 9 has a first heat exchange section 9a arranged downstream of the refrigerant fluid accumulation device 8 and upstream of the first expansion device 31 and a second heat exchange section 9b arranged downstream of the second heat exchanger 2. Heat is exchanged between the refrigerant fluid in the first heat exchange section 9a and the refrigerant fluid in the second heat exchange section 9b. The internal exchanger 9 makes it possible to improve the performance of the thermal conditioning system 100.

[0192] According to a variant not shown, the main circuit A of refrigerant fluid can have a supercooling exchanger arranged downstream of the accumulation device 8 and upstream of the first expansion valve 31. The supercooling exchanger makes it possible to increase the thermal cooling power when the thermal conditioning system is used in cooling mode.

Claims

1. A control method for controlling a thermal conditioning system (100), the thermal conditioning system (100) comprising: - a heat transfer fluid circuit (20) configured to circulate a heat transfer fluid, - a refrigerant fluid circuit (10) having: - a main loop (A) comprising, in the flow direction of the refrigerant fluid, in this order: - a compressor (7) configured to be driven by an electric motor (6), the compressor (7) being configured to bring the refrigerant fluid from a suction pressure (Pr_s) to a delivery pressure (Pr_d), - a first heat exchanger (1) configured to provide a heat power (Pw1) to a heat transfer fluid (Fl), a first expansion valve (31), - a second heat exchanger (2) jointly arranged on the refrigerant fluid circuit (10) and on the heat transfer fluid circuit (20) so as to receive a heat power (Pw2) from the heat transfer fluid, - a first bypass branch (B) allowing the refrigerant fluid at the outlet of the compressor (7) to reach the second heat exchanger (2) by bypassing the first exchanger (1) and the first expansion valve (31), the first bypass branch (B) having a second expansion valve (32), the control method comprising the steps of: (i) receiving a heat power setpoint (C_Pw) of the heat power to be provided to the heat transfer fluid (Fl) at the first exchanger (1), (ii) determining an electric power setpoint (C_Pw_el) of the electric power to be provided to the electric motor (6) of the compressor (7) based on the received heat power setpoint (C_Pw) of the heat power to be provided and based on the heat power (Pw2) received by the second exchanger (2), (iii) determining a delivery pressure setpoint (C_Pr_d) based on the determined electric power setpoint (C_Pw_el) and based on a maximum delivery pressure (Pr_d_max), (iv) determining a suction pressure setpoint (C_Pr_s) based on the determined electric power setpoint (C_Pw_el) and based on the determined delivery pressure setpoint (C_Pr_d), (v) controlling the rotational speed (N) of the electric motor (6) of the compressor (7) so that the electric power provided to the compressor (7) is equal to the determined setpoint (C_Pw_el), (vi) controlling the passage cross section of the second expansion valve (32) so that the suction pressure (Ps) of the compressor (7) is equal to the determined suction pressure setpoint (C_Pr_s), (vii) controlling the passage cross section of the first expansion valve (31) so that the refrigerant fluid at the inlet of the compressor (7) is in the superheated vapor state.

2. The method of claim 1, wherein, the main loop (A) of the refrigerant fluid circuit (10) comprising a third expansion valve (33) arranged downstream of the compressor (7) and upstream of the first heat exchanger (1), the method comprising the step of: (viii) controlling the refrigerant fluid passage cross section in the third expansion valve (33) so that the delivery pressure (Pr_d) is equal to the delivery pressure setpoint (C_Pr_d).

3. The method according to claim 1 or 2, comprising the steps of: (vii1) determining a degree of superheat (Sh) of the refrigerant fluid at the inlet of the compressor (7), (vii2) controlling the passage cross section of the first expansion valve (31) so that the degree of superheat (Sh) of the refrigerant fluid at the inlet of the compressor (7) is equal to a setpoint value (C_Sh).

4. The method according to claim 1 or 2, comprising the steps of: (vii1') determining a degree of superheat (Dsh) of the refrigerant fluid at the outlet of the compressor (7), 5. The method of claim 1 or 2, wherein, (vii2') controlling the passage cross section of the first expansion valve (31) so that the degree of superheat of the refrigerant fluid at the outlet of the compressor (7) is equal to a setpoint value (C_Dsh). The main loop (A) of the thermoregulation system (100) comprises a third heat exchanger (3) downstream of the first heat exchanger (1) and upstream of the first expansion device (31), the third heat exchanger (3) being jointly arranged on the refrigerant fluid circuit (10) and on the heat transfer liquid circuit (20) so as to be able to exchange heat between the refrigerant fluid and the heat transfer liquid, the third heat exchanger (3) being configured to provide a heat power (Pw3) to the heat transfer liquid, wherein, in step (i), 6. The method of claim 1 or 2, wherein, the heat power setpoint (Pw) of the heat power to be provided is a total heat power (Pw_tot), the total heat power being the sum of a heat power (Pw1) to be provided to a heat transfer fluid (F1) at the first exchanger (1) and a heat power (Pw3) to be provided to a heat transfer liquid at the third exchanger (3).

7. The method of claim 1 or 2, wherein, The heat transfer fluid (F1) is an internal air flow (Fi) of the interior of a motor vehicle.

8. The method of claim 1 or 2, wherein, The heat transfer fluid (F1) is a heat transfer liquid configured to circulate in a fifth heat exchanger (5) configured to exchange heat with an air flow (Fi) of the interior of a vehicle.

9. The method of claim 5, wherein, The second heat exchanger (2) is thermally coupled to an element (25) of the driveline of the vehicle via the heat transfer liquid of the heat transfer liquid circuit (20). The third heat exchanger (3) is thermally coupled to an element (25) of the driveline of the vehicle via the heat transfer liquid of the heat transfer liquid circuit (20).

10. A thermoregulation system (100), comprising: a heat transfer liquid circuit (20) configured to circulate a heat transfer liquid, a refrigerant fluid circuit (10) having: a main loop (A) comprising, in the direction of flow of the refrigerant fluid, in this order: a compressor (7) configured to be driven by an electric motor (6), the compressor (7) being configured to bring the refrigerant fluid from an intake pressure (Ps) to a delivery pressure (Pd), a first heat exchanger (1) configured to provide a heat power (Pw1) to a heat transfer fluid (F1), a first expansion valve (31), a second heat exchanger (2) jointly arranged on the refrigerant fluid circuit (10) and on the heat transfer liquid circuit (20) so as to receive a heat power (Pw2) from the heat transfer liquid, a third heat exchanger (3) jointly arranged on the refrigerant fluid circuit (10) and on the heat transfer liquid circuit (20) so as to be able to exchange heat between the refrigerant fluid and the heat transfer liquid, the third heat exchanger (3) being configured to provide a heat power (Pw3) to the heat transfer liquid, wherein, in step (i), a first bypass branch (B) allowing the refrigerant fluid at the outlet of said compressor (7) to pass by bypassing said first exchanger (1) and said first expansion valve (31) to reach said second exchanger (2), said first bypass branch (B) comprising a second expansion valve (32), an electronic control unit (50) configured to implement the control method according to any one of the preceding claims.

11. The thermal conditioning system (100) of claim 10, wherein, said refrigerant fluid circuit (10) comprises a second bypass branch (C) arranged in parallel with said first expansion valve (31) and said second heat exchanger (2), said second bypass branch (C) comprising a fourth expansion valve (34) and a fourth heat exchanger (4), wherein said fourth heat exchanger (4) is configured to exchange heat with an air flow (Fi) inside said vehicle.

12. The thermal conditioning system (100) of claim 10 or 11, wherein, a main loop (A) of refrigerant fluid comprising a refrigerant fluid accumulation device (8) arranged downstream of said first exchanger (1) and upstream of said first expansion valve (31). a first bypass branch (B) allowing the refrigerant fluid at the outlet of said compressor (7) to pass by bypassing said first exchanger (1) and said first expansion valve (31) to reach said second exchanger (2), said first bypass branch (B) comprising a second expansion valve (32), an electronic control unit (50) configured to implement the control method according to any one of the preceding claims. said refrigerant fluid circuit (10) comprises a second bypass branch (C) arranged in parallel with said first expansion valve (31) and said second heat exchanger (2), said second bypass branch (C) comprising a fourth expansion valve (34) and a fourth heat exchanger (4), wherein said fourth heat exchanger (4) is configured to exchange heat with an air flow (Fi) inside said vehicle. a main loop (A) of refrigerant fluid comprising a refrigerant fluid accumulation device (8) arranged downstream of said first exchanger (1) and upstream of said first expansion valve (31).

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