Method for controlling a thermal regulation system for a motor vehicle

Abstract

The present invention relates to a method for controlling a heat regulation system (40) for a motor vehicle, the heat regulation system comprising: a condenser (3), the condenser being configured to exchange heat with a first heat transfer fluid (100); a first evaporator (5), the first evaporator being configured to exchange heat with a second heat transfer fluid (200); and a second evaporator (8), the second evaporator being configured to exchange heat with a third heat transfer fluid (300), the heat regulation system being configured so that the temperature (T1_mes) of the second heat transfer fluid (200) and the temperature (T2_mes) of the third heat transfer fluid (300) reach corresponding temperature set points (T1_cons, T2_cons), the control method comprising the following steps: receiving a cooling priority request (step 50), and if both are reached, The thermal power required for the set temperature of the second heat transfer fluid (200) and the set temperature of the third heat transfer fluid (300) is greater than the maximum thermal power, and if priority is given to cooling the third heat transfer fluid (300), then: calculate a modified temperature set point (T1_mod) of the second heat transfer fluid (200) that is greater than the acquired temperature set point (T1_cons) (step 52); adjust the refrigerant flow area through the second expansion device (6) so that the second heat transfer fluid (200) reaches the modified temperature set point (T1_mod) (step 53); increase the modified temperature set point (T1_mod) of the second heat transfer fluid (200) until the third heat transfer fluid (300) reaches the temperature set point (T2_cons) (step 54).

Description

[0001] The present invention relates to the field of thermal regulation systems for motor vehicles. In the case of electric vehicles, such systems allow, for example, thermal regulation of various parts of the vehicle, such as the passenger compartment or the electric energy storage battery. The heat exchange allowing the thermal regulation is mainly obtained by compressing and expanding a refrigerant at the terminals of a plurality of heat exchangers arranged along a closed circuit.

[0002] When two separate evaporators are located in parallel and the two evaporators need to be operated at different evaporation temperatures, it is known practice to locate a pressure regulating valve downstream of one of the evaporators. The pressure drop caused by the pressure regulating valve makes it possible to obtain different pressures in the two evaporators and therefore different temperatures.

[0003] Typically, the evaporator cooling the battery of the vehicle generates a higher temperature than the evaporator cooling the airflow intended for the passenger compartment. Therefore, the pressure regulating valve will be placed downstream of the evaporator cooling the battery. When the battery has a low thermal conductivity, it is difficult to supply sufficient cooling power and it may be beneficial to be able to ensure that the evaporation temperature in the battery evaporator is lower than the evaporation temperature in the passenger compartment evaporator. In addition, a difficulty in using such a system is to manage operating phases during which the cumulative cooling requirements of the passenger compartment and the battery are greater than the maximum cooling capacity of the system. In this case, the allocation of cooling power may give priority to one of the two evaporators in order to meet the cooling requirements of the component considered to have received priority. Priority can be given to passenger compartment cooling or battery cooling depending on the conditions and operating mode. In each case, the evaporator defined as receiving priority will receive the cooling power needed to ensure thermal regulation, while the evaporator defined as not receiving priority will only receive the remaining cooling power. The allocation of cooling power between the two evaporators may be complex to control. The purpose of the present invention is to provide a method for controlling a thermal system that enables stable operation and simple management of the priorities of the two evaporators.

[0004] The invention therefore proposes a method for controlling a thermal conditioning system for a motor vehicle, the thermal conditioning system comprising a refrigerant circuit configured to circulate a refrigerant, the refrigerant circuit comprising:

[0005] - a main loop, which comprises in order in the flow direction of the refrigerant:

[0006] Compression device,

[0007] a condenser configured to exchange heat with the first heat transfer fluid,

[0008] The first expansion device,

[0009] a first evaporator configured to exchange heat with a second heat transfer fluid,

[0010] The second expansion device,

[0011] a bypass branch connecting a first connection point located on the main loop between the condenser and the first expansion device to a second connection point located on the main loop between the second expansion device and the compression device, the bypass branch comprising, in sequence in the flow direction of the refrigerant, a third expansion device and a second evaporator, the second evaporator being configured to exchange heat with a third heat transfer fluid,

[0012] The heat regulation system is configured so that the temperature of the second heat transfer fluid at the outlet of the first evaporator reaches a temperature set point and the temperature of the third heat transfer fluid at the outlet of the second evaporator reaches a temperature set point,

[0013] The control method comprises the following steps:

[0014] - receiving a priority request which gives priority to cooling the second heat transfer fluid or to cooling the third heat transfer fluid,

[0015] - if the heating power required in order to simultaneously reach the temperature set point of the second heat transfer fluid and the temperature set point of the third heat transfer fluid is greater than the heating power supplied jointly by the first evaporator and the second evaporator, increasing the rotational speed of the compression device,

[0016] - If the rotational speed of the compression device has reached a predetermined maximum value, and if priority is given to cooling the third heat transfer fluid, then:

[0017] calculating a modified temperature set point of the second heat transfer fluid at the outlet of the first evaporator that is greater than the acquired temperature set point,

[0018] adjusting the refrigerant flow area through the second expansion device so that the temperature of the second heat transfer fluid reaches the modified temperature set point,

[0019] The modified temperature set point of the second heat transfer fluid is increased until the temperature of the third heat transfer fluid reaches the temperature set point.

[0020] The term "required heating power" refers to the heating power necessary to simultaneously reach the temperature set point of the second heat transfer fluid and the temperature set point of the third heat transfer fluid. Similarly, the term "supplied heating power" refers to the heating power jointly supplied by the first evaporator and the second evaporator. Therefore, the supplied heating power is the sum of the heating power supplied by the first evaporator and the heating power simultaneously supplied by the second evaporator.

[0021] The step of determining the required thermal power includes the following sub-steps:

[0022] - obtaining a temperature set point of the second heat transfer fluid at the outlet of the first evaporator,

[0023] - obtaining a temperature set point of the third heat transfer fluid at the outlet of the second evaporator,

[0024] - determining the temperature of the second heat transfer fluid at the outlet of the first evaporator,

[0025] - determining the temperature of the third heat transfer fluid at the outlet of the second evaporator,

[0026] - if the determined temperature of the second heat transfer fluid is greater than the temperature set point, increasing the rotational speed of the compression device,

[0027] - If the determined temperature of the third heat transfer fluid is greater than the temperature set point, increasing the rotational speed of the compression device.

[0028] In other words, the bypass branch is positioned in parallel with a portion of the main loop including the first expansion device, the first evaporator and the second expansion device.

[0029] According to an aspect of the proposed method, the modified temperature set point of the second heat transfer fluid at the outlet of the first evaporator is calculated by a first proportional-integral controller as a function of the difference between the temperature of the third heat transfer fluid and the temperature set point of the third heat transfer fluid.

[0030] Therefore, the proposed method includes the following steps:

[0031] - tuning a first proportional-integral controller according to a difference between the temperature of the third heat transfer fluid and a temperature set point of the third heat transfer fluid,

[0032] - calculating a modified temperature set point of the second heat transfer fluid by adding together the acquired temperature set point of the second heat transfer fluid and the output parameter of the first proportional-integral controller.

[0033] According to an aspect of the method according to the invention, if priority is given to cooling the third heat transfer fluid, the refrigerant flow area through the second expansion device is controlled by a second proportional-integral controller according to the difference between the temperature of the second heat transfer fluid and the modified temperature set point of the second heat transfer fluid.

[0034] Therefore, the control method according to the present invention comprises the following steps:

[0035] A refrigerant flow area through the second expansion device is reduced to increase the refrigerant pressure in the first evaporator.

[0036] According to one aspect of the method according to the invention, if priority is given to cooling the second heat transfer fluid, the refrigerant flow area through the second expansion device is controlled by a second proportional-integral controller according to the difference between the temperature of the second heat transfer fluid and the temperature set point of the second heat transfer fluid.

[0037] According to an aspect of the invention, the refrigerant flow area through the second expansion device is controlled by a second proportional-integral controller according to a difference between the temperature of the second heat transfer fluid and a temperature set point of the second heat transfer fluid.

[0038] The control method according to the present invention comprises the following steps:

[0039] The refrigerant flow area through the second expansion device is increased to reduce the refrigerant pressure in the first evaporator.

[0040] The control method according to the present invention comprises the following steps:

[0041] If the rotational speed of the compression device has reached a predetermined maximum value, and if priority is given to cooling the second heat transfer fluid, then:

[0042] - calculating a modified temperature set point of the third heat transfer fluid at the outlet of the second evaporator which is greater than the acquired temperature set point,

[0043] - adjusting the refrigerant flow area through the third expansion device so that the temperature of the third heat transfer fluid reaches the modified temperature set point,

[0044] The modified temperature set point of the third heat transfer fluid is increased until the temperature of the second heat transfer fluid reaches the temperature set point.

[0045] According to an aspect of the proposed method, the modified temperature set point of the third heat transfer fluid at the outlet of the second evaporator is calculated by a third proportional-integral controller as a function of the difference between the temperature of the second heat transfer fluid and the temperature set point of the second heat transfer fluid.

[0046] The control method comprises the following steps:

[0047] - tuning a third proportional-integral controller according to the difference between the temperature of the second heat transfer fluid and the temperature set point of the second heat transfer fluid,

[0048] - calculating a modified temperature set point of the third heat transfer fluid by adding together the acquired temperature set point of the third heat transfer fluid and the output parameter of the third proportional-integral controller.

[0049] According to one aspect of the proposed method, if priority is given to cooling the third heat transfer fluid, the refrigerant flow area through the third expansion device is controlled by a fourth proportional-integral controller according to the difference between the temperature of the third heat transfer fluid and the temperature set point of the third heat transfer fluid.

[0050] According to another aspect of the proposed method, if priority is given to cooling the second heat transfer fluid, the refrigerant flow area through the third expansion device is controlled by a fourth proportional-integral controller according to the difference between the temperature of the third heat transfer fluid and a modified temperature set point of the third heat transfer fluid.

[0051] The control method comprises the following steps:

[0052] - determine the speed at which the vehicle is travelling,

[0053] - Determining a maximum value of the rotation speed of the compression device according to the travel speed of the vehicle.

[0054] According to one feature of the method, when the travel speed is greater than 70 km / h, the maximum permissible rotational speed is between 7,000 rpm and 8,000 rpm.

[0055] According to another characteristic of the method, when the travel speed is zero, the maximum permissible rotational speed is between 3,000 rpm and 4,000 rpm.

[0056] The control method according to the present invention comprises the following steps:

[0057] A fifth proportional-integral controller configured to regulate the rotational speed of the compression device is tuned according to a difference between the temperature of the second heat transfer fluid at the outlet of the first evaporator and the temperature set point of the second heat transfer fluid at the outlet of the first evaporator.

[0058] Therefore, the control method according to the present invention further comprises the following steps:

[0059] A sixth proportional-integral controller configured to regulate the rotational speed of the compression device is tuned according to a difference between the temperature of the third heat transfer fluid at the outlet of the second evaporator and the temperature set point of the third heat transfer fluid at the outlet of the second evaporator.

[0060] The method further comprises the following steps:

[0061] The output parameter of the fifth proportional-integral controller and the output parameter of the sixth proportional-integral controller are added together,

[0062] The rotation speed of the compression device is controlled based on the sum of the output parameter of the fifth proportional-integral controller and the output parameter of the sixth proportional-integral controller.

[0063] According to a variant embodiment of the control method (in which the heat conditioning system comprises a refrigerant accumulation device positioned on the main loop, between the condenser and the first connection point), the control method comprises the following steps:

[0064] - determining a refrigerant superheat set point at the outlet of the first evaporator,

[0065] - determine the refrigerant temperature at the outlet of the evaporator,

[0066] - determining the refrigerant superheat value at the outlet of the first evaporator,

[0067] - adjusting the refrigerant flow area through the first expansion device so that the refrigerant superheat value at the outlet of the first evaporator reaches the superheat set point.

[0068] According to an aspect of the control method, a refrigerant flow area through the first expansion device is controlled by a seventh proportional-integral controller according to a difference between a superheat value of the refrigerant at an outlet of the first evaporator and the superheat set point.

[0069] In an exemplary application of the control method, the superheat set point is between 5°C and 15°C.

[0070] The invention also relates to a thermal conditioning system for a motor vehicle, the thermal conditioning system comprising a refrigerant circuit, the refrigerant circuit being configured to circulate a refrigerant, the refrigerant circuit comprising:

[0071] - a main loop, which comprises in order in the flow direction of the refrigerant:

[0072] Compression device,

[0073] a condenser configured to exchange heat with the first heat transfer fluid,

[0074] The first expansion device,

[0075] a first evaporator configured to exchange heat with a second heat transfer fluid,

[0076] The second expansion device,

[0077] a bypass branch connecting a first connection point located on the main loop between the condenser and the first expansion device to a second connection point located on the main loop between the second expansion device and the compression device, the bypass branch comprising, in sequence in the flow direction of the refrigerant, a third expansion device and a second evaporator, the second evaporator being configured to exchange heat with a third heat transfer fluid,

[0078] - An electronic control unit configured to implement the method described above.

[0079] According to one embodiment, the thermal regulation system comprises:

[0080] a heat transfer fluid circuit configured to circulate a fourth heat transfer fluid,

[0081] a first two-fluid heat exchanger, the first two-fluid heat exchanger being commonly arranged on the refrigerant circuit and the heat transfer fluid circuit to allow heat exchange between the refrigerant and the fourth heat transfer fluid,

[0082] a refrigerant accumulation device positioned on the primary loop between the condenser and the first connection point,

[0083] The first dual fluid exchanger is positioned on the main refrigerant circuit between the condenser and the accumulator device.

[0084] According to one embodiment, the thermal regulation system includes a second dual-fluid heat exchanger, which is jointly arranged on the refrigerant circuit and the heat transfer fluid circuit to allow heat exchange between the refrigerant and the fourth heat transfer fluid, and the second dual-fluid heat exchanger is positioned on the main loop, between the accumulation device and the first connection point.

[0085] Furthermore, the thermal regulation system comprises an internal heat exchanger configured to allow heat exchange between the refrigerant circulating in the main loop upstream of the first connection point and the refrigerant circulating in the main loop downstream of the second expansion device.

[0086] According to an exemplary application of the thermal regulation system, the first heat transfer fluid is an airflow outside the passenger compartment of the vehicle, and the second heat transfer fluid is an airflow inside the passenger compartment of the vehicle. The third heat transfer fluid is a heat transfer liquid configured to exchange heat with an electric energy storage battery of the vehicle.

[0087] According to another exemplary application of the thermal conditioning system, the first heat transfer fluid is an air flow outside the passenger compartment of the vehicle, the second heat transfer fluid is a heat transfer liquid configured to exchange heat with an electric energy storage battery of the vehicle, and the third heat transfer fluid is an air flow inside the passenger compartment of the vehicle. In other words, the roles of the first evaporator 5 and the second evaporator 8 are opposite compared to the previous scenario.

[0088] Preferably, the heat transfer fluid circuit comprises a first radiator configured to exchange heat between the fourth heat transfer fluid and an air flow inside the passenger compartment of the vehicle.

[0089] More preferably, the heat transfer fluid circuit comprises a second radiator configured to exchange heat between the fourth heat transfer fluid and an air flow outside the passenger compartment of the vehicle.

[0090] According to an embodiment of the thermal regulation system, the heat transfer fluid circuit comprises a first circulation loop, the first circulation loop comprises the first radiator and a first pump, the first pump being configured to circulate the fourth heat transfer fluid in the first circulation loop.

[0091] According to one embodiment, the heat transfer fluid circuit further comprises a second circulation loop comprising the second radiator and elements of the electric powertrain of the vehicle.

[0092] Advantageously, the second circulation loop comprises a second pump configured to circulate the fourth heat transfer fluid in the second circulation loop.

[0093] Preferably, the heat transfer fluid circuit comprises a first connecting branch fluidically connecting the first circulation loop and the second circulation loop.

[0094] The heat transfer fluid circuit further comprises a second connecting branch which fluidly connects the first circulation loop and the second circulation loop.

[0095] According to one embodiment, the first connecting branch connects a connecting point on the first circulation loop between the second pump and the second radiator to a connecting point on the second circulation loop between the first radiator and the first pump.

[0096] Furthermore, the second connecting branch connects a connecting point on the first circulation loop between the second radiator and the element to a connecting point on the second circulation loop between the first pump and a connecting point between the first circulation loop and the first connecting branch.

[0097] Further characteristics and advantages of the invention will become apparent on reading the detailed description of an embodiment given as a non-limiting example, and on reading the following drawings:

[0098] - Figure 1 shows a schematic diagram of a heat regulation system implementing the method according to the invention according to a first embodiment,

[0099] - Figure 2 shows a schematic diagram of a heat regulation system implementing the method according to the invention according to a second embodiment,

[0100] - Figure 3 is a functional diagram of a method according to the invention;

[0101] - Figure 4is a block diagram of a method according to the present invention.

[0102] In order to make the drawings easier to read, different elements are not necessarily shown in proportion. In these drawings, the same elements have the same reference numerals. Some elements or parameters can be indexed, i.e. specifying, for example, the first element or the second element, or the first parameter and the second parameter, etc. The purpose of this index is to distinguish similar but not identical elements or parameters. This index does not mean that an element or parameter is any priority over another element or parameter, and these names are interchangeable. Similarly, in the embodiment in which the first element is optional, when the first element does not exist, the second element can exist. In the following description, the term "the first element upstream of the second element" means relative to the circulation direction of the fluid, and the first element is before the second element. Similarly, the term "the first element downstream of the second element" means relative to the circulation direction of the fluid in question, and the first element is after the second element.

[0103] Figure 1 A thermal conditioning system 40 for a motor vehicle according to a simple first embodiment is shown. The thermal conditioning system 40 comprises a refrigerant circuit 1 which is configured to circulate a refrigerant, the refrigerant circuit 1 comprising:

[0104] - Main loop A, which includes in order in the flow direction of the refrigerant:

[0105] Compression device 2,

[0106] a condenser 3, which is configured to exchange heat with the first heat transfer fluid 100,

[0107] The first expansion device 4,

[0108] a first evaporator 5, which is configured to exchange heat with a second heat transfer fluid 200,

[0109] The second expansion device 6,

[0110] a bypass branch B connecting a first connection point 11 located on the main circuit A between the condenser 3 and the first expansion device 4 to a second connection point 12 located on the main circuit A between the second expansion device 6 and the compression device 2,

[0111] The bypass branch B comprises, in the flow direction of the refrigerant, a third expansion device 7 and a second evaporator 8 in sequence, the second evaporator being configured to exchange heat with the third heat transfer fluid 300.

[0112] - Electronic control unit 9.

[0113] The electronic control unit 9 is configured to implement a method according to the invention, which will be described below.

[0114] The electronic control unit 9 receives information from various sensors which measure, in particular, the characteristics of the refrigerant at different points on the circuit. The electronic control unit 9 also receives set points requested by the occupants of the vehicle, such as the desired temperature inside the passenger compartment. The electronic unit 9 implements control laws for operating the various actuators in order to control the thermal conditioning system 40. Figure 1 and Figure 2 In the figure, the dotted lines represent the electrical connections between the electronic control unit 9, the compression device 2 and the expansion devices 4, 6, 7. For simplicity, the various sensors present in the refrigerant circuit are not shown.

[0115] exist Figure 1 and Figure 2 In the illustrated example, the first heat transfer fluid 100 is an airflow outside the vehicle's passenger compartment, while the second heat transfer fluid 200 is an airflow inside the vehicle's passenger compartment. The third heat transfer fluid 300 is a heat transfer liquid configured to exchange heat with the vehicle's electrical energy storage battery 10 .

[0116] In other words, the second heat transfer fluid 200 is an airflow intended to be delivered to the interior of the passenger compartment of the vehicle in order to ensure thermal conditioning of the passenger compartment. In particular, the thermal conditioning system 40 makes it possible to regulate the temperature and humidity of the air inside the passenger compartment of the vehicle in order to ensure the comfort of the passengers. The first evaporator 5 is positioned in a heating, ventilation and air conditioning device (commonly referred to as "HVAC"). Such a device is not shown in the drawings. If necessary, a motor fan unit (not shown in the drawings) is positioned in the HVAC device in order to increase the flow rate of the internal airflow.

[0117] External airflow refers to airflow that is not intended for the passenger compartment. Here, the condenser 3 is positioned on the front of the vehicle and in particular receives the airflow generated by the forward travel of the vehicle. If necessary, a motor fan unit (not shown) can be activated to increase the flow rate of the external airflow.

[0118] During normal operation of the heat conditioning system 40, a refrigerant circulates in at least a part of the refrigerant circuit 1. Here, the refrigerant used is a chemical fluid such as R1234yf. Other refrigerants may be used, such as R134a.

[0119] The compression device 2 is configured to cause the refrigerant flow to go from a low pressure to a high pressure, which is greater than the low pressure. The compression device 2 may be an electric compressor, i.e. a compressor having moving parts driven by a motor. The compression device 2 comprises a suction side for low-pressure refrigerant (also referred to as the inlet of the compression device) and a discharge side for high-pressure refrigerant (also referred to as the outlet of the compression device). The internal moving parts of the compressor cause the refrigerant to go from a low pressure on the inlet side to a high pressure on the outlet side. After expansion in one or more expansion members of the circuit, the refrigerant returns to the inlet of the compressor 2 and a new cycle begins. Controlling the rotation speed of the motor makes it possible to control the refrigerant flow discharged by the compression device, which corresponds to the flow traveling through the refrigerant circuit.

[0120] The refrigerant circuit comprises a main loop A defining a closed loop, and a bypass branch B. The bypass branch B is positioned in parallel with a portion of the main loop A comprising a first expansion device 4, a first evaporator 5 and a second expansion device 6. The main loop A and the bypass branch B are fluidly connected at a first connection point 11 and a second connection point 12. The first connection point 11 is a flow splitting point, i.e., the refrigerant flow circulating upstream of the first connection point 11 can be divided between a portion that continues to follow the main loop A and an additional portion that follows the bypass branch B. The second connection point 12 is a flow confluence point, i.e., the refrigerant flow from the main loop A merges with the flow from the bypass branch B. These flows are then combined into a single flow and returned to the compression device 2.

[0121] Therefore, the pressure of the refrigerant at the outlet of the second expansion device 6 is equal to the pressure at the outlet of the second evaporator 8. "Equal pressures" means equal within the pressure drop difference. The pipe extending between the outlet of the second expansion device 6 and the second connection point 12 is not necessarily the same as the pipe extending between the outlet of the second evaporator 8 and the second connection point 12. Therefore, the pressure drop between the outlet of the second expansion device 6 and the second connection point 12 is not strictly the same as the pressure drop between the outlet of the second evaporator 8 and the second connection point 12, but the difference will be regarded as negligible.

[0122] Here, the first expansion device 4 is an electronic expansion valve. This means that the expansion device has a movable gate in the refrigerant circulation pipeline, which is controlled by a motor and an electronic circuit. The movement of the gate makes it possible to modify the refrigerant flow area in the pipeline and thus adjust the degree of expansion produced by the expansion device. For a given position of the movable gate, the flow area is the lateral area of ​​an equivalent pipe that allows the same fluid flow as the expansion device. Therefore, the flow area is a function of the position of the movable gate. Similarly, in the example shown, the second expansion device 6 is an electronic expansion valve. The third expansion device 7 is also an electronic expansion valve.

[0123] A typical use case of the thermal regulation device 40 is as follows: it is desired to regulate the temperature of the passenger compartment and the temperature of the electric energy storage battery simultaneously. To this end, the first evaporator 5 performs thermal regulation of the second heat transfer fluid 200, i.e. the air flow intended for the passenger compartment of the vehicle. The second evaporator 8 performs thermal regulation of a third heat transfer fluid, which is here a heat transfer liquid, such as a water-glycol mixture. This water-glycol mixture exchanges heat with the battery and makes it possible to regulate the temperature of the battery. The condenser 3 makes it possible to dissipate heat from the high-pressure refrigerant into the external air flow.

[0124] When the second expansion device 6 expands the refrigerant, the pressure in the first evaporator 5 is higher than the pressure in the second evaporator 8. Therefore, two different evaporation temperatures can be obtained, the evaporation temperature in the first evaporator 5 being higher than the evaporation temperature in the second evaporator 8. Therefore, a greater cooling power can be obtained in the second evaporator 8, which is here connected to the battery of the vehicle. This configuration is particularly beneficial when the thermal conductivity of the battery is low. Low thermal conductivity is not conducive to obtaining high thermal power, so it is beneficial to be able to increase the difference between the temperature of the fluid to be cooled and the evaporation temperature when the evaporator is in operation.

[0125] The invention proposes a method for controlling a thermal conditioning system 40 for a motor vehicle, the thermal conditioning system comprising a refrigerant circuit 1, the refrigerant circuit being configured to circulate a refrigerant, the refrigerant circuit 1 comprising:

[0126] - Main loop A, which includes in order in the flow direction of the refrigerant:

[0127] Compression device 2,

[0128] a condenser 3, which is configured to exchange heat with the first heat transfer fluid 100,

[0129] The first expansion device 4,

[0130] a first evaporator 5, which is configured to exchange heat with a second heat transfer fluid 200,

[0131] The second expansion device 6,

[0132] a bypass branch B connecting a first connection point 11 located on the main circuit A between the condenser 3 and the first expansion device 4 to a second connection point 12 located on the main circuit A between the second expansion device 6 and the compression device 2,

[0133] The bypass branch B comprises, in the flow direction of the refrigerant, a third expansion device 7 and a second evaporator 8 in sequence, the second evaporator being configured to exchange heat with the third heat transfer fluid 300.

[0134] The heat regulation system is configured so that the temperature T1_mes of the second heat transfer fluid 200 at the outlet of the first evaporator 5 reaches the temperature set point T1_cons and the temperature T2_mes of the third heat transfer fluid 300 at the outlet of the second evaporator 8 reaches the temperature set point T2_cons,

[0135] The control method comprises the following steps:

[0136] - receiving a priority request which gives priority to cooling the second heat transfer fluid 200 or to cooling the third heat transfer fluid 300 (step 50),

[0137] - if the heating power required to simultaneously reach the temperature set point of the second heat transfer fluid 200 and the temperature set point of the third heat transfer fluid 300 is greater than the heating power jointly supplied by the first evaporator 5 and the second evaporator 8, then the rotation speed of the compression device 2 is increased (step 51),

[0138] If the rotation speed of the compression device 2 has reached a predetermined maximum value N_max and if priority is given to cooling the third heat transfer fluid 300, then:

[0139] calculating a modified temperature set point T1_mod of the second heat transfer fluid 200 at the outlet of the first evaporator 5 which is greater than the acquired temperature set point T1_cons (step 52),

[0140] adjusting the refrigerant flow area through the second expansion device 6 so that the temperature of the second heat transfer fluid 200 reaches the modified temperature set point T1_mod (step 53),

[0141] The modified temperature set point T1_mod of the second heat transfer fluid 200 is increased until the temperature T2_mes of the third heat transfer fluid 300 reaches the temperature set point T2_cons (step 54 ).

[0142] The term "required thermal power" refers to the thermal power necessary to simultaneously reach the temperature set point of the second heat transfer fluid 200 and the temperature set point of the third heat transfer fluid 300. Similarly, the term "supplied thermal power" refers to the thermal power jointly supplied by the first evaporator 5 and the second evaporator 8. Therefore, the supplied thermal power is the sum of the thermal power supplied by the first evaporator and the thermal power simultaneously supplied by the second evaporator.

[0143] When the thermal power required to simultaneously reach the temperature set point of the second heat transfer fluid 200 and the temperature set point of the third heat transfer fluid 300 is less than the maximum thermal power that the system can supply, it is not necessary to define the respective priorities of these heat transfer fluids. The system can be operated so that the first evaporator 5 and the second evaporator 8 regulate the temperatures of the flows of the second heat transfer fluid 200 and the third heat transfer fluid 300 to their respective temperature set points.

[0144] At a given moment, when the required thermal power is greater than the supplied power, the rotation speed of the compression device 2 is increased. As a result, the refrigerant flow increases, and the supplied thermal power is increased. When the required thermal power is still greater than the supplied power, the rotation speed of the compression device is increased until the rotation speed potentially reaches the maximum rotation speed of the compression device 2. At this point, the supplied power cannot be increased any more, and therefore the supplied thermal power is equal to the maximum power.

[0145] When the thermal power required to simultaneously reach the temperature set point of the second heat transfer fluid 200 and the temperature set point of the third heat transfer fluid 300 is greater than the maximum thermal power that the system can supply, it is no longer possible to simultaneously reach the second heat transfer fluid 200 and the third heat transfer fluid 300 to their respective temperature set points. By way of example, such a situation occurs when the condenser 3 is capable of dissipating 10 kilowatts, while the cooling requirement at the first evaporator 5 is 7 kilowatts and the cooling requirement at the second evaporator 8 is 5 kilowatts. Therefore, the total required cooling power is 12 kW, while the maximum power that can be supplied is only 10 kW. Therefore, a decision must be made on the thermal power distribution between the first evaporator 5 and the second evaporator 8.

[0146] Thus, the priority request makes it possible to define which of the second heat transfer fluid 200 and the third heat transfer fluid 300 obtains priority. The heat transfer fluid defined as obtaining priority will receive the thermal power necessary to regulate the temperature of the heat transfer fluid to the temperature set point. The heat transfer fluid defined as not obtaining priority will only receive the difference between the maximum power that can be supplied and the power allocated to the heat transfer fluid defined as obtaining priority. Therefore, it will not be possible to regulate the temperature of the heat transfer fluid defined as not obtaining priority to the desired temperature set point. It should be noted that defining a heat transfer fluid as obtaining priority is equivalent to defining the associated evaporator as obtaining priority. Therefore, saying that the second heat transfer fluid 200 is defined as obtaining priority is the same as saying that the first evaporator 5 is defined as obtaining priority. Similarly, saying that the third heat transfer fluid 300 is defined as obtaining priority is the same as saying that the second evaporator 8 is defined as obtaining priority. The priority request is managed by the electronic control unit 9 according to the operating conditions of the vehicle and the wishes of the occupants of the vehicle. The purpose of the proposed method is to ensure that the system is stably operated with a satisfactory distribution of power between the different heat transfer fluids.

[0147] When priority is given to cooling the third heat transfer fluid 300, the sub-step consisting of adjusting the refrigerant flow area through the second expansion device 6 makes it possible to increase the refrigerant pressure in the first evaporator 5. Therefore, the evaporation pressure in the first evaporator 5 is higher than the evaporation pressure in the second evaporator 8. Therefore, the evaporation temperature of the refrigerant in the second evaporator 8 is lower than the evaporation temperature of the refrigerant in the first evaporator 5.

[0148] The step of determining the required thermal power includes the following sub-steps:

[0149] - obtaining the temperature set point T1_cons of the second heat transfer fluid 200 at the outlet of the first evaporator 5,

[0150] - obtaining the temperature set point T2_cons of the third heat transfer fluid 300 at the outlet of the second evaporator 8,

[0151] - determining the temperature T1_mes of the second heat transfer fluid 200 at the outlet of the first evaporator 5,

[0152] - determining the temperature T2_mes of the third heat transfer fluid 300 at the outlet of the second evaporator 8,

[0153] - if the determined temperature T1_mes of the second heat transfer fluid 200 is greater than the temperature set point T1_cons, increasing the rotation speed of the compression device 2,

[0154] If the determined temperature T2_mes of the third heat transfer fluid 300 is greater than the temperature set point T2_cons, the rotation speed of the compression device 2 is increased.

[0155] like Figure 3 As diagrammatically shown in FIG. 1 , the modified temperature set point T1_mod of the second heat transfer fluid 200 at the outlet of the first evaporator 5 is calculated by the first proportional-integral controller PI1 from the difference between the temperature T2_mes of the third heat transfer fluid 300 and the temperature set point T2_cons of the third heat transfer fluid 300. This calculation is performed when the priority request gives priority to cooling the third heat transfer fluid 300 (i.e., gives priority to the action of the second evaporator 8).

[0156] In order to successfully calculate the modified temperature set point T1_mod of the second heat transfer fluid 200, the control method therefore comprises the following steps:

[0157] - tuning the first proportional-integral controller PI1 as a function of the difference between the temperature T2_mes of the third heat transfer fluid 300 and the temperature set point T2_cons of the third heat transfer fluid 300 (step 55 ),

[0158] - Calculating a modified temperature set point T1_mod of the second heat transfer fluid 200 by adding together the acquired temperature set point T1_cons of the second heat transfer fluid and the output parameter of the first proportional-integral controller PI1 (step 56 ).

[0159] If priority is given to cooling the third heat transfer fluid 300 , the refrigerant flow area through the second expansion device 6 is controlled by the second proportional integral controller PI2 according to the difference between the temperature T1_mes of the second heat transfer fluid 200 and its modified temperature set point T1_mod.

[0160] Therefore, the control method according to the present invention comprises the following steps:

[0161] The refrigerant flow area through the second expansion device 6 is reduced to increase the refrigerant pressure in the first evaporator 5 .

[0162] (Step 57)

[0163] Therefore, the refrigerant flow area through the second expansion device 6 is controlled by the second proportional-integral controller PI2 according to the difference between the temperature T1_mes of the second heat transfer fluid 200 and the temperature set point T1_cons of the second heat transfer fluid 200 .

[0164] If priority is given to cooling the second heat transfer fluid 200 , the refrigerant flow area through the second expansion device 6 is controlled by the second proportional integral controller PI2 according to the difference between the temperature T1_mes of the second heat transfer fluid 200 and the temperature set point T1_cons of the second heat transfer fluid 200 .

[0165] When cooling priority is given to the second heat transfer fluid 200, the control method according to the present invention comprises the following steps:

[0166] The refrigerant flow area through the second expansion device 6 is increased to reduce the refrigerant pressure in the first evaporator 5. (Step 58). As a result, the evaporation pressure in the first evaporator 5 can be reduced, which also reduces the evaporation temperature and tends to increase the cooling power supplied by the first evaporator 5.

[0167] The temperature of the second heat transfer fluid 200 (i.e., the actual temperature of the second heat transfer fluid) can be measured at the outlet of the first evaporator 5. For example, a temperature measuring sensor can be fastened to a portion of the fins of the evaporator 5. The temperature of the second heat transfer fluid 200 can also be measured a little further downstream of the second heat transfer fluid 200. For example, the heating of the heat transfer fluid between the evaporator 5 and the measurement point, downstream of the first evaporator 5, can be modeled, and the recalculation of the value at the outlet of the first evaporator 5 should take this heating into account. Similarly, the temperature of the third heat transfer fluid 300 can be measured at the outlet of the second evaporator 8.

[0168] The control method according to the present invention comprises the following steps:

[0169] If the rotation speed of the compression device 2 has reached a predetermined maximum value N_max, and if priority is given to cooling the second heat transfer fluid 200, then:

[0170] - calculation of a modified temperature set point T2_mod of the third heat transfer fluid 300 at the outlet of the second evaporator 8 which is greater than the acquired temperature set point T2_cons,

[0171] - adjusting the refrigerant flow area through the third expansion device 7 so that the temperature of the third heat transfer fluid 300 reaches the modified temperature set point T2_mod,

[0172] The modified temperature set point T2_mod of the third heat transfer fluid 300 is increased until the temperature T1_mes of the second heat transfer fluid 200 reaches the temperature set point T1_cons (step 59 ).

[0173] The modified temperature set point T2_mod of the third heat transfer fluid 300 at the outlet of the second evaporator 8 is calculated by the third proportional-integral controller PI3 from the difference between the temperature T1_mes of the second heat transfer fluid 200 and the temperature set point T1_cons of the second heat transfer fluid 200. This calculation is performed when the priority request gives priority to cooling the second heat transfer fluid 200 (i.e., gives priority to the action of the first evaporator 5).

[0174] To this end, the control method comprises the following steps:

[0175] - tuning the third proportional-integral controller PI3 according to the difference between the temperature T1_mes of the second heat transfer fluid 200 and the temperature set point T1_cons of the second heat transfer fluid 200,

[0176] - Calculating a modified temperature set point T2_mod of the third heat transfer fluid 300 by adding together the acquired temperature set point T2_cons of the third heat transfer fluid 300 and the output parameter of the third proportional-integral controller PI3 (step 60 ).

[0177] If priority is given to cooling the third heat transfer fluid 300 , the refrigerant flow area through the third expansion device 7 is controlled by the fourth proportional integral controller PI4 according to the difference between the temperature T2_mes of the third heat transfer fluid 300 and the temperature set point T2_cons of the third heat transfer fluid 300 .

[0178] If priority is given to cooling the second heat transfer fluid 200 , the refrigerant flow area through the third expansion device 7 is controlled by the fourth proportional integral controller PI4 according to the difference between the temperature T2_mes of the third heat transfer fluid 300 and the modified temperature set point T2_mod of the third heat transfer fluid 300 .

[0179] In other words, when the priority heat transfer fluid changes, the structure of the control of the third expansion device 7 is unchanged. This structure is a parameter used as a reference for the modified proportional integral controller. The control remains stable during the priority changeover.

[0180] Here, the maximum value N_max of the rotation speed of the compressor 2 is not a constant value. The maximum permissible speed in terms of the mechanical durability of the compressor 2 is not necessarily acceptable to the passengers of the vehicle due to the noise generated.

[0181] Therefore, the control method comprises the following steps:

[0182] - determine the vehicle's speed,

[0183] - Determine the maximum value N_max of the rotation speed of the compression device 2 according to the travel speed of the vehicle (step 61 ).

[0184] When the travel speed is greater than 70 km / h, the maximum permissible rotational speed N_max is between 7,000 rpm and 8,000 rpm. When the travel speed is zero, the maximum permissible rotational speed N_max is between 3,000 rpm and 4,000 rpm. When the background noise generated by the travel of the vehicle increases, a higher rotational speed of the compressor 2 can be allowed. The noise generated by the compression device 2 is now partially masked by the background noise.

[0185] In order to control the rotation speed of the compression device 2, the control method according to the present invention comprises the following steps:

[0186] The fifth proportional integral controller PI5 configured to regulate the rotation speed of the compression device 2 is tuned according to the difference between the temperature T1_mes of the second heat transfer fluid 200 at the outlet of the first evaporator 5 and the temperature set point T1_cons of the second heat transfer fluid 200 at the outlet of the first evaporator 5 (step 62).

[0187] Therefore, the control method according to the present invention further comprises the following steps:

[0188] The sixth proportional integral controller PI6 configured to regulate the rotation speed of the compression device 2 is tuned according to the difference between the temperature T2_mes of the third heat transfer fluid 300 at the outlet of the second evaporator 8 and the temperature set point T2_cons of the third heat transfer fluid 300 at the outlet of the second evaporator 8 (step 63).

[0189] The method further comprises the following steps:

[0190] The output parameter of the fifth proportional-integral controller PI5 and the output parameter of the sixth proportional-integral controller PI6 are added together,

[0191] The rotation speed of the compression device 2 is controlled based on the sum of the output parameter of the fifth proportional-integral controller PI5 and the output parameter of the sixth proportional-integral controller PI6.

[0192] According to a variant embodiment of the control method (in which the heat conditioning system comprises a refrigerant accumulation device 16 positioned on the main circuit, between the condenser 3 and the first connection point 11), the control method comprises the following steps:

[0193] - determining the refrigerant superheat set point Sur_Cons at the outlet of the first evaporator 5,

[0194] - determining the refrigerant temperature at the outlet of the evaporator 5,

[0195] - Determine the refrigerant superheat value Sur_mes at the outlet of the first evaporator 5,

[0196] - Adjust the refrigerant flow area through the first expansion device 4 so that the refrigerant superheat value Sur_mes at the outlet of the first evaporator 5 reaches the superheat set point Sur_cons (step 65).

[0197] It should be remembered that the superheat of a refrigerant at a given pressure is the difference between the actual temperature of the refrigerant and the saturation temperature corresponding to the pressure in question. The term "superheat" does not apply to two-phase refrigerants. Zero superheat corresponds to a completely gaseous refrigerant whose temperature is equal to the saturation temperature.

[0198] The refrigerant flow area through the first expansion device 4 is controlled by a seventh proportional-integral controller PI7 according to the difference between the refrigerant superheat value Sur_mes at the outlet of the first evaporator 5 and the superheat set point Sur_cons.

[0199] In one exemplary application of the control method, the superheat set point Sur_cons is between 5° C. and 15° C. This superheat value at the outlet of the first evaporator 5 makes it possible to optimize the efficiency of the first evaporator 5, but also ensures that the droplet of the refrigerant at the inlet of the compression device 2 is within the correct range (i.e., ensures that the amount of liquid refrigerant arriving at the low-pressure inlet of the compressor 2 is not excessive).

[0200] Figure 2 There is shown a second embodiment of a thermal conditioning system 40. In this embodiment, an additional heat exchanger is used.

[0201] Therefore, the thermal regulation system 40 comprises:

[0202] a heat transfer fluid circuit 20 configured to circulate a fourth heat transfer fluid 400,

[0203] a first two-fluid heat exchanger 15, which is commonly arranged on the refrigerant circuit 1 and the heat transfer fluid circuit 20 to allow heat exchange between the refrigerant and the fourth heat transfer fluid 400,

[0204] a refrigerant accumulation device 16, which is positioned on the main circuit A between the condenser 3 and the first connection point 11,

[0205] The first dual fluid exchanger 15 is positioned on the main refrigerant circuit A between the condenser 3 and the accumulation device 16 .

[0206] The accumulation device 16 is a receiver-type dryer. Like the third heat transfer fluid 300, the fourth heat transfer fluid 400 is a water-glycol mixture.

[0207] exist Figure 2 In the example, the thermal regulation system includes a second dual-fluid heat exchanger 17, which is arranged jointly on the refrigerant circuit 1 and the heat transfer fluid circuit 20 to allow heat exchange between the refrigerant and the fourth heat transfer fluid 400, and the second dual-fluid heat exchanger 17 is positioned on the main loop A, between the accumulation device 16 and the first connection point 11.

[0208] In other words, when the condenser 3 does not allow sufficient heat exchange to condense the entire refrigerant flow passing through it, the first two-fluid heat exchanger 15 makes it possible to complete the condensation. The second two-fluid heat exchanger 17 subcools the refrigerant leaving the receiver dryer 16. Figure 1Compared with the configuration in Figure 2 The configuration in makes it possible to increase the total cooling power. As a result, the performance of the thermal regulation system is improved.

[0209] The thermal regulation system 40 comprises an internal heat exchanger 18 configured to allow heat exchange between the refrigerant circulating in the main circuit A upstream of the first connection point 11 and the refrigerant circulating in the main circuit A downstream of the second expansion device 6 .

[0210] The internal heat exchangers 18a, 18b allow heat exchange between the high-pressure refrigerant circulating in the portion of the circuit downstream of the second two-fluid exchanger 17 and upstream of the first connection point 11 and the low-pressure refrigerant circulating in the portion of the circuit downstream of the second expansion device 6 and upstream of the second connection point 12. Reference numeral 18a denotes the portion of the internal exchanger in which the high-pressure refrigerant circulates, and reference numeral 18b denotes the portion of the internal exchanger in which the low-pressure refrigerant circulates. Figure 2 In the block diagram in FIG. 1 , 18a and 18b are separated from each other, which is not the case in reality. Therefore, the internal heat exchanger 18 helps to improve the maximum cooling power.

[0211] The heat transfer fluid circuit 20 comprises a first radiator 19 which is configured to exchange heat between a fourth heat transfer fluid 400 and an airflow inside the passenger compartment of the vehicle. In other words, the first radiator 19 is used to heat the passenger compartment. Here, the internal airflow corresponds to the second heat transfer fluid 200 .

[0212] The heat transfer fluid circuit 20 further includes a second radiator 23 configured to exchange heat between the fourth heat transfer fluid 400 and an airflow outside the passenger compartment of the vehicle. The second radiator 23 may be positioned upstream of the condenser 3. In other words, the external airflow first passes through the second radiator 23 and then passes through the condenser 3. Here, the first heat transfer fluid 100 corresponds to the external airflow.

[0213] The heat transfer fluid circuit 20 includes a first circulation loop 21 including a first radiator 19 and a first pump 25 configured to circulate a fourth heat transfer fluid 400 in the first circulation loop 21 .

[0214] The heat transfer fluid circuit 20 also includes a second circulation loop 22, which includes a second radiator 23 and an element 24 of the electric powertrain of the vehicle. The element 24 can be, for example, an electric drive motor or an electronic power unit supplying electric power to the drive motor. The element 24 can also be an assembly formed by an electric drive motor and an associated electronic power unit.

[0215] The second circulation loop 22 includes a second pump 26 configured to circulate the fourth heat transfer fluid 400 in the second circulation loop 22 .

[0216] The heat transfer fluid circuit 20 includes a first connection branch 27 that fluidly connects the first circulation loop 21 and the second circulation loop 22. The heat transfer fluid circuit 20 includes a second connection branch 28 that fluidly connects the first circulation loop 21 and the second circulation loop 22.

[0217] More specifically, the first connecting branch 27 connects a connecting point 41 located on the first circulation loop 21 between the second pump 26 and the second radiator 23 to a connecting point 42 located on the second circulation loop 22 between the first radiator 19 and the first pump 25. The second connecting branch 28 connects a connecting point 43 located on the first circulation loop 21 between the second radiator 23 and the element 24 to a connecting point 44 located on the second circulation loop 22 between the first pump 25 and the connecting point 42 between the first circulation loop 21 and the first connecting branch 27.

[0218] This configuration makes it possible to ensure cooling of the heat transfer liquid 400 in all the different operating modes.

[0219] Heat from the electric motor and / or the electronic power unit 24 may be dissipated at the second heat sink 23 into the external air flow.

[0220] According to an embodiment not shown, the heat regulating circuit according to the invention may also include one or more of the following features considered individually or in combination with one another:

[0221] The first heat transfer fluid 100 may be air flow outside the vehicle's passenger compartment, the second heat transfer fluid 200 may be a heat transfer liquid configured to exchange heat with the vehicle's electrical energy storage battery 10, and the third heat transfer fluid 300 may be air flow inside the vehicle's passenger compartment.

[0222] The first two-fluid exchanger 15 is optional and may not be present. In this case, the main circuit comprises a refrigerant accumulation device 16 in the form of a receiver dryer, wherein the second two-fluid heat exchanger 17 is positioned downstream of the refrigerant accumulation device. Thus, the second two-fluid heat exchanger 17 subcools the refrigerant.

[0223] The second two-fluid exchanger 17 is also optional and may not be present. In this case, the first two-fluid exchanger 15 makes it possible to complete the condensation of the refrigerant. A refrigerant accumulation device 16 in the form of a receiver dryer is positioned downstream of the first two-fluid exchanger 15 .

Claims

1. A method for controlling a thermal conditioning system (40) for a motor vehicle, the thermal conditioning system comprising a refrigerant circuit (1), the refrigerant circuit being configured to circulate a refrigerant, the refrigerant circuit (1) comprising: - a main loop (A), comprising in order in the flow direction of the refrigerant: Compression device (2), a condenser (3) configured to exchange heat with a first heat transfer fluid (100), a first expansion device (4), a first evaporator (5) configured to exchange heat with a second heat transfer fluid (200), a second expansion device (6), - a bypass branch (B), the bypass branch connecting a first connection point (11) located on the main loop (A) between the condenser (3) and the first expansion device (4) to a second connection point (12) located on the main loop (A) between the second expansion device (6) and the compression device (2), the bypass branch (B) comprising a third expansion device (7) and a second evaporator (8) in sequence in the flow direction of the refrigerant, the second evaporator being configured to exchange heat with a third heat transfer fluid (300), the heat regulation system being configured to make the temperature (T1_mes) of the second heat transfer fluid (200) at the outlet of the first evaporator (5) reach a temperature set point (T1_cons) and to make the temperature (T2_mes) of the third heat transfer fluid (300) at the outlet of the second evaporator (8) reach a temperature set point (T2_cons), the control method comprising the following steps: - receiving a priority request, the priority request giving priority to cooling the second heat transfer fluid (200) or to cooling the third heat transfer fluid (300) (step 50), - if the thermal power required in order to simultaneously reach the temperature set point of the second heat transfer fluid (200) and the temperature set point of the third heat transfer fluid (300) is greater than the thermal power jointly supplied by the first evaporator (5) and the second evaporator (8), then increasing the rotation speed of the compression device (2) (step 51), - If the rotation speed of the compression device (2) has reached a predetermined maximum value (N_max), and if priority is given to cooling the third heat transfer fluid (300), then: calculating a modified temperature set point (T1_mod) of the second heat transfer fluid (200) at the outlet of the first evaporator (5) which is greater than the acquired temperature set point (T1_cons) (step 52), adjusting the refrigerant flow area through the second expansion device (6) so that the temperature of the second heat transfer fluid (200) reaches the modified temperature set point (T1_mod) (step 53), The modified temperature set point (T1_mod) of the second heat transfer fluid (200) is increased until the temperature (T2_mes) of the third heat transfer fluid (300) reaches the temperature set point (T2_cons) (step 54).

2. The control method according to claim 1, wherein: The modified temperature set point (T1_mod) of the second heat transfer fluid (200) at the outlet of the first evaporator (5) is calculated by a first proportional integral controller (PI1) based on the difference between the temperature (T2_mes) of the third heat transfer fluid (300) and the temperature set point (T2_cons) of the third heat transfer fluid (300).

3. The control method according to claim 1 or 2, wherein: If priority is given to cooling the third heat transfer fluid (300), the refrigerant flow area through the second expansion device (6) is controlled by a second proportional integral controller (PI2) based on the difference between the temperature (T1_mes) of the second heat transfer fluid (200) and the modified temperature set point (T1_mod) of the second heat transfer fluid (200).

4. The control method according to claim 1, wherein: If priority is given to cooling the second heat transfer fluid (200), the refrigerant flow area through the second expansion device (6) is controlled by a second proportional integral controller (PI2) according to the difference between the temperature (T1_mes) of the second heat transfer fluid (200) and the temperature set point (T1_cons) of the second heat transfer fluid (200).

5. The control method according to claim 1, comprising the following steps: The refrigerant flow area through the second expansion device (6) is reduced to increase the refrigerant pressure in the first evaporator (5) (step 57).

6. The control method according to claim 1, comprising the following steps: If the rotational speed of the compression device (2) has reached a predetermined maximum value (N_max), and if priority is given to cooling the second heat transfer fluid (200), then: - calculating a modified temperature set point (T2_mod) of the third heat transfer fluid (300) at the outlet of the second evaporator (8) that is greater than the acquired temperature set point (T2_cons), - adjusting the refrigerant flow area through the third expansion device (7) so that the temperature of the third heat transfer fluid (300) reaches the modified temperature set point (T2_mod), The modified temperature set point (T2_mod) of the third heat transfer fluid (300) is increased until the temperature (T1_mes) of the second heat transfer fluid (200) reaches the temperature set point (T1_cons) (step 59).

7. The control method according to claim 6, wherein: The modified temperature set point (T2_mod) of the third heat transfer fluid (300) at the outlet of the second evaporator (8) is calculated by a third proportional integral controller (PI3) based on the difference between the temperature (T1_mes) of the second heat transfer fluid (200) and the temperature set point (T1_cons) of the second heat transfer fluid (200).

8. The control method according to claim 1, wherein: If priority is given to cooling the third heat transfer fluid (300), the refrigerant flow area through the third expansion device (7) is controlled by a fourth proportional integral controller (PI4) according to the difference between the temperature (T2_mes) of the third heat transfer fluid (300) and the temperature set point (T2_cons) of the third heat transfer fluid (300).

9. The control method according to claim 1 in combination with claim 6, wherein: If priority is given to cooling the second heat transfer fluid (200), the refrigerant flow area through the third expansion device (7) is controlled by a fourth proportional integral controller (PI4) according to the difference between the temperature (T2_mes) of the third heat transfer fluid (300) and the modified temperature set point (T2_mod) of the third heat transfer fluid (300).

10. The control method according to claim 1, comprising the following steps: - tuning a fifth proportional-integral controller (PI5) configured to regulate the rotational speed of the compression device (2) according to the difference between the temperature (T1_mes) of the second heat transfer fluid (200) at the outlet of the first evaporator (5) and the temperature set point (T1_cons) of the second heat transfer fluid (200) at the outlet of the first evaporator (5) (step 62), - tuning a sixth proportional-integral controller (PI6) configured to regulate the rotational speed of the compression device (2) according to the difference between the temperature (T2_mes) of the third heat transfer fluid (300) at the outlet of the second evaporator (8) and the temperature set point (T2_cons) of the third heat transfer fluid (300) at the outlet of the second evaporator (8) (step 63), - adding together the output parameter of the fifth proportional-integral controller (PI5) and the output parameter of the sixth proportional-integral controller (PI6), Based on the sum of the output parameter of the fifth proportional-integral controller (PI5) and the output parameter of the sixth proportional-integral controller (PI6), the rotation speed of the compression device (2) is controlled (step 64).

11. The control method according to claim 1, wherein: The heat conditioning system comprises a refrigerant accumulation device (16) positioned on the main loop between the condenser (3) and the first connection point (11), and the control method comprises the following steps: - determining the refrigerant superheat set point (Sur_Cons) at the outlet of said first evaporator (5), - determining the refrigerant temperature at the outlet of the first evaporator (5), - determining the refrigerant superheat value (Sur_mes) at the outlet of the first evaporator (5), -Adjusting the refrigerant flow area through the first expansion device (4) so ​​that the refrigerant superheat value (Sur_mes) at the outlet of the first evaporator (5) reaches the superheat set point (Sur_cons) (step 65), wherein the refrigerant flow area through the first expansion device (4) is controlled by a seventh proportional integral controller (PI7) according to the difference between the refrigerant superheat value (Sur_mes) at the outlet of the first evaporator (5) and the superheat set point (Sur_cons).

12. A thermal conditioning system (40) for a motor vehicle, the thermal conditioning system comprising a refrigerant circuit (1), the refrigerant circuit being configured to circulate a refrigerant, the refrigerant circuit (1) comprising: - a main loop (A), said main loop comprising, in order in the flow direction of said refrigerant: Compression device (2), a condenser (3) configured to exchange heat with a first heat transfer fluid (100), a first expansion device (4), a first evaporator (5) configured to exchange heat with a second heat transfer fluid (200), a second expansion device (6), - a bypass branch (B), which connects a first connection point (11) located on the main loop (A) between the condenser (3) and the first expansion device (4) to a second connection point (12) located on the main loop (A) between the second expansion device (6) and the compression device (2), the bypass branch (B) comprising, in sequence in the flow direction of the refrigerant, a third expansion device (7) and a second evaporator (8), the second evaporator being configured to exchange heat with a third heat transfer fluid (300), - An electronic control unit (9) configured to implement the method according to one of the preceding claims.

13. The thermal conditioning system (40) according to the preceding claim, comprising: a heat transfer fluid circuit (20) configured to circulate a fourth heat transfer fluid (400), a first double fluid heat exchanger (15) arranged jointly on the refrigerant circuit (1) and the heat transfer fluid circuit (20) to allow heat exchange between the refrigerant and the fourth heat transfer fluid (400), a refrigerant accumulation device (16) positioned on the main circuit (A) between the condenser (3) and the first connection point (11), The first two-fluid heat exchanger (15) is positioned on the main loop (A), between the condenser (3) and the accumulation device (16).

14. The thermal regulation system (40) as described in claim 12 or 13 comprises a second dual-fluid heat exchanger (17), which is arranged jointly on the refrigerant circuit (1) and the heat transfer fluid circuit (20) to allow heat exchange between the refrigerant and the fourth heat transfer fluid (400), and the second dual-fluid heat exchanger (17) is positioned on the main loop (A), between the accumulation device (16) and the first connection point (11).

15. The thermal conditioning system (40) of claim 12, wherein: The first heat transfer fluid (100) is an airflow outside the passenger compartment of the vehicle, the second heat transfer fluid (200) is an airflow inside the passenger compartment of the vehicle, and the third heat transfer fluid (300) is a heat transfer liquid configured to exchange heat with an electrical energy storage battery (10) of the vehicle.

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