Method for controlling a thermal regulation system

Abstract

A method for controlling a thermal conditioning system (100) is disclosed, the thermal conditioning system comprising: a heat transfer liquid circuit (20); the refrigerant circuit (10) is provided with: a compressor (7); a first heat exchanger (1) supplying a first thermal power (Pw1) to the heat transfer fluid (F1); a first expansion valve (31); a second heat exchanger (2) supplying a second thermal power (Pw2) to the heat transfer liquid; a second expansion valve (32); the invention relates to a method for controlling a first heat exchanger (1), a second heat exchanger (2), a third heat exchanger (3), comprising the steps of: (i) receiving a total thermal power setpoint (CPw) of the total thermal power to be supplied, the total thermal power setpoint being the sum of a first thermal power setpoint (CPw1) of the first heat exchanger (1) and a second thermal power setpoint (CPw2) of the second heat exchanger (2), (ii) controlling the pressure of the refrigerant in the first heat exchanger (1), (iii) controlling the flow area of the first expansion valve (31) such that the supplied total thermal power equals the total thermal power setpoint (CPw), (iii) controlling the flow area of the first expansion valve (31) such that the supplied second thermal power (Pw2) equals the second thermal power setpoint (CPw2).

Description

Technical Field

[0001] The invention relates to the field of thermal regulation systems. Thermal regulation systems of this type can in particular equip motor vehicles. When the traction chain of the vehicle is electric, these systems make it possible to thermally regulate different components of the vehicle, such as the passenger space or the electric energy storage batteries. The heat exchange is mainly controlled by the compression and expansion of a coolant fluid within a plurality of heat exchangers. Background Art

[0002] Thermal regulation systems usually use a coolant fluid circuit and a heat transfer liquid circuit that exchanges heat with the coolant fluid. Such systems are therefore called indirect. A compressor ensures the passage of high-pressure coolant fluid.

[0003] It is known to locate in series in a coolant fluid circuit: a first heat exchanger which makes it possible to ensure the heating of the air flow flowing to the passenger space of the vehicle; a second heat exchanger which makes it possible to heat an element of the traction chain of the vehicle; and a third heat exchanger which makes it possible to further cool this element of the traction chain of the vehicle. Said element of the traction chain is, for example, an electrical energy storage battery. The second exchanger and the third exchanger are, for example, located jointly on the coolant fluid circuit and on the heat transfer liquid circuit. The heat transfer liquid circulating in the circuit makes it possible to ensure heat exchange with the elements of the traction chain. Depending on the operating mode, it is thus possible to supply heat to an element of the traction chain of the vehicle in order to heat it, or to recover heat from it in order, for example, to transfer heat to the air flow supplying the passenger space in order to heat it. In a particular operating mode, the air of the passenger space is heated by the first heat exchanger, while the heating of the heat transfer liquid is ensured at the second heat exchanger.

[0004] The total thermal power supplied by the heat regulation system is thus distributed between a first thermal power supplied by the first exchanger and a second thermal power supplied by the second exchanger. Ensuring accurate control of the thermal power supplied by each exchanger is problematic.

[0005] The object of the present disclosure is to propose a control method which makes it possible to reliably control the total thermal power supplied and its distribution between the two heat exchangers. Summary of the invention

[0006] To this end, the present invention proposes a method for controlling a heat regulation system, the heat regulation system comprising:

[0007] - a heat transfer liquid circuit configured to circulate a heat transfer liquid;

[0008] - A coolant fluid circuit, comprising in order in the flow direction of the coolant fluid:

[0009] --compressor;

[0010] a first heat exchanger configured to supply a first thermal power to the heat transfer fluid;

[0011] --First expansion valve;

[0012] a second heat exchanger, arranged jointly on the coolant fluid circuit and the heat transfer liquid circuit, in order to supply a second thermal power to the heat transfer liquid;

[0013] --Second expansion valve;

[0014] --The third heat exchanger;

[0015] The control method comprises the following steps:

[0016] (i) receiving a total thermal power set point to be supplied, the total thermal power set point being the sum of a first thermal power set point to be supplied to a heat transfer liquid in a first exchanger and a second thermal power set point to be supplied to a heat transfer liquid in a second exchanger; (ii) controlling the pressure of the coolant fluid in the first exchanger so that the sum of the first thermal power supplied and the second thermal power supplied is equal to the total thermal power set point to be supplied; and (iii) controlling the through cross section of the first expansion valve so that the second thermal power supplied by the second exchanger is equal to the second thermal power set point to be supplied.

[0017] In step (iii), the first expansion valve performs a partial expansion of the coolant fluid such that the second thermal power supplied by the second exchanger is equal to the second thermal power set point to be supplied.

[0018] This partial expansion makes it possible to reduce the condensation temperature in the second heat exchanger, thereby adjusting the distribution of the total thermal power between the power supplied to the first heat exchanger and the power supplied to the second heat exchanger. The desired distribution can be obtained.

[0019] The features listed in the following paragraphs can be implemented independently of each other or in all technically possible combinations:

[0020] According to one embodiment, the heat conditioning system is a heat conditioning system for a motor vehicle.

[0021] The passage cross section of the first expansion valve is controlled by a proportional-integral regulator.

[0022] The passage cross section of the second expansion valve is controlled by a proportional-integral regulator.

[0023] This type of regulator ensures reliable regulation while keeping programming and adjustment simple.

[0024] According to one embodiment of the method, step (ii) comprises the following sub-steps:

[0025] (ii1) determining a temperature set point of the coolant fluid in the first exchanger based on the first thermal power set point and the flow rate set point of the heat transfer liquid; (ii2) determining a pressure set point of the coolant fluid in the first exchanger from the determined temperature set point.

[0026] Preferably, in step (ii1 ), the temperature set point of the coolant fluid in the first exchanger is also determined according to the input temperature of the coolant fluid in the first exchanger.

[0027] According to one aspect of the control method, step (ii) comprises the following sub-steps:

[0028] The speed of the compressor is controlled so that the pressure of the refrigerant fluid in the first exchanger is equal to the determined pressure set point.

[0029] The pressure of the coolant fluid in the first exchanger can be measured by a measuring sensor located at the input of the first exchanger.

[0030] The compressor is configured to move the refrigerant fluid from a suction pressure to a delivery pressure.

[0031] According to one aspect of the control method, wherein the compressor is configured to cause the coolant fluid to reach a delivery pressure from a suction pressure, the step (i) comprises the following sub-steps:

[0032] A delivery pressure set point of the compressor is determined as a function of the determined pressure set point of the coolant fluid in the first exchanger.

[0033] According to one aspect of the control method, step (ii) comprises the following sub-steps:

[0034] (ii1) Controlling the speed of the compressor so that the delivery pressure of the compressor is equal to the determined delivery pressure set point.

[0035] According to an embodiment of the method, the pressure of the coolant fluid in the first exchanger is substantially equal to the delivery pressure of the compressor.

[0036] The pressure of the coolant fluid in the first exchanger is estimated, for example, from a measurement of the delivery pressure of the compressor.

[0037] According to one embodiment of the method, the heat transfer fluid is an air flow in the passenger space of the motor vehicle.

[0038] According to a further embodiment of the method, the heat transfer liquid is a heat transfer liquid configured to circulate in a fifth heat exchanger configured to exchange heat with an air flow in a passenger space of the vehicle.

[0039] According to one aspect of the method, the second heat exchanger is thermally coupled to an element of the traction chain of the vehicle via a heat transfer fluid of the heat transfer fluid circuit.

[0040] The second heat exchanger thus makes it possible to supply thermal power to an element of the vehicle's traction chain, ie to heat this element in order to increase its temperature.

[0041] According to an embodiment of the method, the third heat exchanger is thermally coupled to an element of the traction chain of the vehicle via a heat transfer liquid of the heat transfer liquid circuit.

[0042] The third heat exchanger thus makes it possible to absorb heat from an element of the vehicle's traction chain in order to keep its temperature within acceptable limits, or to transfer the absorbed heat to another unit.

[0043] Elements of the electric traction chain include, for example, the electric traction motor of the vehicle.

[0044] As a variant or in addition, the elements of the electric traction chain include an electronic module for controlling the electric traction motor of the vehicle.

[0045] Also as a variant or in addition, the elements of the electric traction chain include an electrical energy storage battery.

[0046] The present invention also relates to a heat regulation system, comprising:

[0047] - a heat transfer liquid circuit configured to circulate a heat transfer liquid;

[0048] - A coolant fluid circuit comprising:

[0049] --The main loop, in the direction of flow of the coolant fluid, includes:

[0050] ---compressor;

[0051] ---a first heat exchanger configured to supply a first thermal power to the heat transfer liquid;

[0052] ---First expansion valve;

[0053] ---a second heat exchanger, arranged jointly on the coolant fluid circuit and the heat transfer liquid circuit, so as to supply a second thermal power to the heat transfer liquid;

[0054] ---Second expansion valve;

[0055] ---The third heat exchanger;

[0056] - An electronic control unit configured to implement the aforementioned control method.

[0057] According to one embodiment, the main coolant fluid loop comprises a coolant fluid accumulation device located downstream of the second exchanger and upstream of the second expansion valve.

[0058] According to another embodiment, the main coolant fluid circuit comprises a coolant fluid accumulation device located downstream of the third exchanger and upstream of the compressor.

[0059] According to one embodiment of the heat regulation system, the coolant fluid circuit comprises a first branch positioned in parallel with the second expansion valve and the third heat exchanger, the first branch comprising the third expansion valve and the fourth heat exchanger.

[0060] The thermal regulation system comprises a first branch fluidly connecting a first connection point on the main loop downstream of the second exchanger and upstream of the second expansion valve to a second connection point on the main loop downstream of the third exchanger and upstream of the compressor, the first branch comprising a third expansion valve.

[0061] According to an embodiment of the thermal conditioning system, the fourth heat exchanger is configured to exchange heat with an air flow in a passenger space of the vehicle.

[0062] According to one embodiment, the coolant fluid circuit comprises a second branch allowing the coolant fluid at the output of the compressor to reach the third exchanger by bypassing the first exchanger, the second exchanger and the second expansion valve, the second branch comprising a fourth expansion valve.

[0063] The thermal regulation system comprises a second branch fluidly connecting a third connection point on the main loop downstream of the compressor and upstream of the first exchanger to a fourth connection point on the main loop downstream of the second expansion valve and upstream of the third exchanger, the second branch comprising a fourth expansion device.

[0064] According to one embodiment, in which the main loop of the coolant fluid circuit comprises a fifth expansion valve downstream of the compressor and upstream of the first exchanger, the coolant fluid is expanded by the fifth expansion valve and the pressure of the coolant fluid present in the first exchanger is lower than the delivery pressure of the compressor.

[0065] The pressure of the coolant fluid in the first exchanger is estimated from the measured value of the pressure of the coolant fluid at the output of the fifth expansion valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Other features, details and advantages will become apparent from a reading of the following detailed description and an analysis of the accompanying drawings, in which:

[0067] [ Figure 1 ] is a schematic diagram of a heat conditioning system according to a first embodiment, in which a control method according to the present invention is implemented;

[0068] [ Figure 2 ] is a schematic diagram of a heat regulation system according to a second embodiment, in which a control method according to the present invention is implemented;

[0069] [ Figure 3 ]yes Figure 2 A schematic diagram of a variation of a heat regulation system;

[0070] [ Figure 4 ]yes Figure 2 A schematic diagram of another variation of a heat regulation system;

[0071] [ Figure 5 ] is a thermodynamic diagram of the coolant fluid state during the implementation of the control method;

[0072] [ Figure 6 ] is a block diagram illustrating the different steps of the method according to the present invention. DETAILED DESCRIPTION

[0073] In order to make the drawings easier to read, different elements are not necessarily shown to scale. In these figures, the same elements have the same reference numerals. Certain elements or parameters can be indexed, i.e., specified by, for example, the first element or the second element, or the first parameter and the second parameter. The purpose of this index is to distinguish similar but not identical elements or parameters. This index does not mean the priority of one element or parameter relative to another element or parameter, and the names can be interchangeable.

[0074] In the following description, the term "a first element upstream of a second element" means that the first element is located before the second element relative to the circulation or travel direction of the fluid. Similarly, the expression "a first element downstream of a second element" means that the first element is located after the second element relative to the circulation or travel direction of the fluid. In the case of a coolant fluid circuit, the term "a first element upstream of the second element" means that the coolant fluid travels successively along the first element and then the second element without passing through a compression device. In other words, the coolant fluid leaves the compression device, passes through one or optionally a plurality of elements, then passes through the first element, then passes through the second element, and then optionally returns to the compression device after having passed through the other elements.

[0075] The term “the second element is located between the first element and the third element” means that the shortest path from the first element to the third element passes through the second element.

[0076] When a subsystem is specified to include a given element, this does not exclude the presence of other elements in the subsystem.

[0077] In the thermal conditioning system 100 described, the electronic control unit 50 receives information from various sensors (not shown), in particular measuring the properties of the coolant fluid at various points on the circuit. The electronic control unit also receives set points issued by the vehicle occupants, such as the desired temperature in the passenger space. The electronic control unit executes a control law allowing the control of the various actuators in order to control the thermal conditioning system 100, ensuring that the set points are received. The electronic control unit 50 implements in particular the method according to the invention.

[0078] The compression device 7 may be an electric compressor, i.e. a compressor whose movable parts are driven by an electric motor. The compression device 7 comprises a side for sucking in a low-pressure coolant fluid, also referred to as an input end 7a of the compression device, and a side for delivering a high-pressure coolant fluid, also referred to as an output end 7b of the compression device 7. The compressor 7 is configured to bring the coolant fluid from a suction pressure Pr_s to a delivery pressure Pr_d.

[0079] The suction pressure is the so-called low pressure state and the delivery pressure is the so-called high pressure state. The movable parts inside the compressor 7 cause the coolant fluid to change from the low pressure state at the input side 7a to the high pressure state at the output side 7b. After expansion in one or more expansion devices, the coolant fluid returns to the input part 7a of the compressor 7 and a new thermodynamic cycle begins.

[0080] The coolant fluid circuit 10 forms a closed loop in which the coolant fluid can circulate. When the coolant fluid circuit 10 is in normal working condition, that is, without faults or leaks, it is sealed. Each connection point of the circuit 10 allows the coolant fluid to enter one or another circuit part that meets at the connection point. By adjusting the opening or closing of the shut-off valve, check valve or expansion device included on each of the branches, the coolant fluid is distributed between the circuit parts that meet at the connection point. In other words, each connection point is a means for changing the direction of the coolant fluid arriving at the connection point. Therefore, the shut-off valve and the check valve make it possible to selectively guide the coolant fluid to different branches of the coolant fluid circuit in order to ensure different operating modes, which will be described below.

[0081] In this case, the coolant fluid used by the coolant fluid circuit 1 is a chemical fluid, such as R1234yf. Other coolant fluids, such as R134a, R290 or R744, may also be used.

[0082] "Interior air flow Fi" refers to the air flow toward the passenger compartment of the motor vehicle. This interior air flow can circulate in a device for heating, ventilation and / or air conditioning, which is usually indicated by the term "HVAC". Such a device is not shown in the various figures.

[0083] Figure 1A first embodiment of a thermal conditioning system 100 is shown, comprising:

[0084] - a heat transfer liquid circuit 20 configured to circulate a heat transfer liquid;

[0085] - Coolant fluid circuit 10, comprising:

[0086] --Main loop A, along the flow direction of the coolant fluid, includes:

[0087] ---Compressor 7;

[0088] --- a first heat exchanger 1 , configured to supply a first thermal power Pw1 to the heat transfer liquid F1 ;

[0089] ---First expansion valve 31;

[0090] --- a second heat exchanger 2, arranged jointly on the coolant fluid circuit 10 and the heat transfer liquid circuit 20, in order to supply a second thermal power Pw2 to the heat transfer liquid;

[0091] --- Second expansion valve 32;

[0092] ---The third heat exchanger 3;

[0093] An electronic control unit 50 configured to implement a control method that will be described in detail below.

[0094] The first heat exchanger 1 is configured to exchange heat with a heat transfer liquid F1. The first heat exchanger 1 can operate as a condenser. The condensation heat of the coolant fluid is transferred to the heat transfer liquid F1. A heating power designated as a first heating power Pw1 is thus supplied to the heat transfer liquid F1.

[0095] The supplied first thermal power Pw1 is the thermal power supplied by the coolant fluid to the heat transfer liquid F1 in the first heat exchanger 1 .

[0096] The second heat exchanger 2 is a dual fluid exchanger. In other words, the second heat exchanger 2 comprises a first compartment through which a coolant fluid passes and a second compartment through which a heat transfer liquid passes. The two compartments are sealed and can exchange heat. The dual fluid exchanger 2 comprises an input 2a and an output 2b for the coolant fluid, and an input and an output for the heat transfer liquid, which are not numbered in the illustrative drawings. The second exchanger 2 is, for example, a plate exchanger.

[0097] Like the first exchanger 1 , the second exchanger 2 can be operated as a condenser. The heat of condensation of the coolant fluid can be transferred to a heat transfer liquid circulating in the second exchanger 2 .

[0098] The supplied second thermal power Pw2 is the thermal power supplied by the coolant fluid to the heat transfer liquid circuit 20 within the second heat exchanger 2 .

[0099] The third heat exchanger 3 is also a dual fluid exchanger.

[0100] Each expansion valve is a device for the expansion of a coolant fluid. Each expansion valve makes it possible to adjust the degree of expansion of the coolant fluid when passing through the expansion valve. Each expansion valve is configured to change the passage cross section of the coolant fluid. The "passage cross section" refers to the surface area through which the coolant fluid flows when the coolant fluid passes through the expansion valve.

[0101] Each expansion valve comprises a coolant fluid input and a coolant fluid output. The output and the input are connected by a channel fluid. The movable baffle makes it possible to control the passage cross section of the channel, i.e. the channel surface area provided to the cooling fluid. The expansion valve is, for example, an electronic expansion valve, i.e. the movable baffle is actuated by an electric motor controlled by an electronic control unit. The position of the movable baffle can be controlled in a closed loop, i.e. the position of the movable baffle is measured and adjusted in real time in order to obtain a position set point. The passage cross section of the coolant fluid can be continuously adjusted between a closed position and a maximum open position. The electronic control module of each expansion valve can be integrated into the corresponding expansion valve. According to a variant, the electronic control unit 50 can also ensure the command and control of each expansion valve.

[0102] According to the embodiment shown here, the thermal conditioning system 100 is a thermal conditioning system for a motor vehicle.

[0103] exist Figure 1 In the embodiment of the invention, the heat transfer liquid F1 is an interior air flow F1 to the passenger space of a motor vehicle. The first heat exchanger 1 is located in a heating, ventilation and / or air conditioning device. The first exchanger 1 thus makes it possible to heat the passenger space of the vehicle.

[0104] The second heat exchanger 2 is thermally coupled to an element 25 of the vehicle's traction chain via a heat transfer liquid of a heat transfer liquid circuit 20. The second heat exchanger 2 thus makes it possible to supply thermal power to the element 25 of the vehicle's traction chain, i.e. to heat the element to increase its temperature. The heating of the element 25 of the traction chain can be put into use, for example, by negative ambient temperatures during a phase of putting the vehicle into operation, the element being, for example, an electrical energy storage battery.

[0105] In other words, the heat transfer liquid circulating in the heat transfer liquid circuit 20 exchanges heat with the element 25 of the vehicle's traction chain, which allows heat exchange, i.e. thermal coupling, between the element 25 and the second heat exchanger 2. The heat transfer liquid is, for example, a mixture of water and ethylene glycol. The heat transfer liquid can also be a dielectric liquid, i.e. an electrically insulating liquid.

[0106] The element 25 of the electric traction chain comprises, for example, an electric traction motor of the vehicle. As a variant, or in a complementary manner, the element 25 of the electric traction chain comprises an electric energy storage battery. Also as a variant, or in a complementary manner, the element 25 of the electric traction chain comprises an electronic module for controlling the electric traction motor of the vehicle.

[0107] The third heat exchanger 3 is thermally coupled to an element 25 of the vehicle's traction chain via a heat transfer fluid of a heat transfer fluid circuit 20 .

[0108] The third heat exchanger 3 thus makes it possible to absorb heat from an element 25 of the traction chain of the vehicle in order to keep its temperature within acceptable limits, or to transfer the absorbed heat to another unit. The joint action of the second exchanger 2 and the third exchanger 3 makes it possible to ensure thermal regulation of the element 25 of the traction chain according to the various operating modes. The heat transfer liquid circuit 20 is not illustrated in detail and is represented by dashed lines at the third exchanger 3 and the second exchanger 2. In order to simplify the representation and avoid crossings between the lines of different circuits, the circuit 20 is represented as two different parts.

[0109] The heat transfer liquid circuit 20 comprises at least one circulation pump (not shown) which allows the heat transfer liquid to circulate in the circuit 20 .

[0110] according to Figure 1 In the embodiment of the present invention, the main circuit A of the coolant fluid comprises a coolant fluid accumulation device 8 located downstream of the second exchanger 2 and upstream of the second expansion valve 32. The device 8 for accumulating the coolant fluid is a dehydration cylinder. Depending on the operating mode of the thermal conditioning system 100, the accumulation device 8 makes it possible to compensate for variations in the quality of the coolant fluid circulating in the circuit 10.

[0111] A possible operating mode of the heat regulation system is one in which the coolant fluid supplies heat to the heat transfer liquid F1 at the first exchanger 1, supplies storage heat to the heat transfer liquid at the second exchanger 2, and receives heat at the third exchanger 3. The heat transfer liquid F1 receives a first thermal power Pw1 at the first exchanger 1, and the heat transfer liquid receives a second thermal power Pw2 at the second exchanger 2. During operation of the heat regulation system 100, it is desirable to be able to vary these two powers Pw1, Pw2 independently of each other. In other words, for a given total power, it is desirable to be able to adjust the distribution of this total power between the first power Pw1 and the second power Pw2.

[0112] Therefore, the present invention proposes a method for controlling a heat regulation system 100, the heat regulation system 100 comprising:

[0113] a heat transfer liquid circuit 20 configured to circulate a heat transfer liquid;

[0114] The coolant fluid circuit 10 comprises, in order in the flow direction of the coolant fluid:

[0115] Compressor 7;

[0116] A first heat exchanger 1 , configured to supply a first thermal power Pw1 to the heat transfer liquid F1 ;

[0117] A first expansion valve 31;

[0118] a second heat exchanger 2, arranged jointly on the coolant fluid circuit 10 and the heat transfer liquid circuit 20, in order to supply a second thermal power Pw2 to the heat transfer liquid;

[0119] A second expansion valve 32;

[0120] The third heat exchanger 3.

[0121] The control method comprises the following steps:

[0122] (i) receiving a total thermal power set point C_Pw to be supplied, the total thermal power set point C_Pw to be supplied being the sum of a first thermal power set point C_Pw1 to be supplied to the heat transfer liquid F1 in the first exchanger 1 and a second thermal power set point C_Pw2 to be supplied to the heat transfer liquid in the second exchanger 2; (ii) controlling the pressure of the coolant fluid in the first exchanger 1 so that the sum of the first thermal power Pw1 supplied and the second thermal power Pw2 supplied is equal to the total thermal power set point C_Pw to be supplied; and (iii) controlling the passing cross section of the first expansion valve 31 so that the second thermal power Pw2 supplied by the second exchanger 2 is equal to the second thermal power set point C_Pw2 to be supplied.

[0123] In step (iii), the first expansion valve 31 performs a partial expansion of the coolant fluid so that the second thermal power Pw2 supplied by the second exchanger 2 is equal to the second thermal power setpoint C_Pw2 to be supplied.

[0124] This partial expansion makes it possible to reduce the condensation temperature in the second heat exchanger 2, thereby adjusting the distribution of the total thermal power between the power supplied to the first heat exchanger 1 and the power supplied to the second heat exchanger 2. The desired distribution can be obtained.

[0125] The total power setpoint C_Pw as well as the first C_Pw1 and the second C_Pw2 thermal power setpoints can be processed in different ways.

[0126] For example, a total thermal power setpoint C_Pw may be issued with a distribution setpoint between the first and second thermal powers. In other words, the total power to be supplied is known, as is the portion of the total power that must be distributed between the first thermal power Pw1 and the second thermal power Pw2.

[0127] Alternatively, the first set point C_Pw1 of the first heating power may be directly received, and the second set point C_Pw2 of the second heating power may also be received.

[0128] Figure 5 It is shown that when the method described herein is implemented, Figure 1 Operation of the thermal regulation system 100.

[0129] This figure illustrates the thermodynamic state of the coolant fluid during the thermodynamic cycle. The value on the x-axis is the enthalpy H of the coolant fluid. The value on the y-axis is the coolant fluid pressure P on a logarithmic scale. The curve S is the characteristic saturation curve of the coolant fluid used. The illustrated area contained between the saturation curve S and the y-axis corresponds to the two-phase field of the coolant fluid.

[0130] Point A7a represents the state of the coolant fluid at the input 7a of the compressor 7. The pressure of the coolant fluid there is equal to the suction pressure Pr_s. Point A7b represents the state of the coolant fluid at the output 7b of the compressor 7. The pressure there is equal to the delivery pressure Pr_d. The enthalpy and pressure of the coolant fluid at the input of the first exchanger 1 are substantially equal to the enthalpy and pressure of point A7b. Point A1b represents the state of the coolant fluid at the output 1b of the first exchanger 1. The enthalpy difference between the input 1a and the output 1b of the first exchanger 1 (marked by reference Q1) represents the supplied first thermal power Pw1. The first expansion valve 31 performs a partial expansion of the coolant fluid so that the pressure of the coolant fluid in the second exchanger 2 is lower than the pressure of the coolant fluid in the first exchanger 1. Point A2a illustrates the state of the coolant fluid at the input of the second exchanger 2. Point A8 illustrates the state of the coolant fluid at the output of the accumulation device 8. The change in enthalpy in the second exchanger 2 marked by reference Q2 represents the supplied second thermal power Pw2. The level of expansion provided by the first expansion valve 31 (schematically illustrated by the vertical distance between point A1 b and point A2 a ) makes it possible to adjust the condensation temperature of the coolant fluid in the second exchanger 2 , and thus the second thermal power Pw2 .

[0131] The second expansion valve 32 expands the coolant fluid until it is in a low-pressure state. Point A32a shows the state of the coolant fluid upstream of the second expansion valve 32, and point A32b shows the state of the coolant fluid downstream of the second expansion valve 32. The low-pressure coolant fluid evaporates in the third exchanger 3 and reaches the input 7a of the compressor 7. The change in enthalpy between point A32b and point A7a represents the thermal power absorbed by the coolant fluid in the third exchanger 3, i.e., during the passage from the input 3a to the output 3b of the third exchanger 3.

[0132] The through cross section of the first expansion valve 31 is controlled by a proportional-integral regulator. Similarly, the through cross section of the second expansion valve 32 is controlled by a proportional-integral regulator. This type of regulator ensures reliable regulation while keeping programming and adjustment simple. It should be understood that other types of regulators can be used.

[0133] Step (ii) comprises the following sub-steps:

[0134] (ii1) determining a temperature set point C_T1 of the coolant fluid in the first exchanger 1 according to the first thermal power set point C_Pw1 and the flow set point C_Q1 of the heat transfer liquid F1; (ii2) determining a pressure set point C_P1 of the coolant fluid in the first exchanger 1 from the determined temperature set point C_T1.

[0135] Preferably, in step (ii1 ), the temperature set point C_T1 of the coolant fluid in the first exchanger 1 is also determined as a function of the input temperature T1_i of the coolant fluid in the first exchanger 1 .

[0136] The step (ii1) of determining the temperature set point C_T1 of the coolant fluid in the first exchanger 1 is based on the fact that the temperature of the heat transfer liquid F1 after heat exchange in the first exchanger 1 is related to the temperature of the coolant fluid in the first exchanger 1 .

[0137] Therefore, the temperature set point of the coolant fluid can be derived from the temperature to be reached by the heat transfer liquid F1.

[0138] The supplied first thermal power Pw_1 is equal to the flow rate Q1 of the heat transfer liquid F1 multiplied by the heat capacity of the heat transfer liquid F1 and multiplied by the difference between the output temperature of the heat transfer liquid F1 and the input temperature of the heat transfer liquid F1 in the first exchanger 1 .

[0139] Since the input temperature of the heat transfer liquid F1 , ie the temperature before heat exchange in the first exchanger 1 , is known, a target for the output temperature of the heat transfer liquid F1 can be determined. The set temperature C_T1 of the coolant fluid is thereby determined.

[0140] According to one embodiment, the temperature of the heat transfer liquid F1 at the output of the first exchanger 1 is the same as the temperature of the coolant fluid in the second exchanger 1 .

[0141] According to one embodiment, the ratio between the temperature of the heat transfer liquid F1 at the output of the first exchanger 1 and the temperature of the coolant fluid in the first exchanger 1 is determined according to the flow rate of the heat transfer liquid F1. For example, the target value of the temperature of the coolant fluid in the first exchanger 1 can be tabulated according to the temperature of the heat transfer liquid at the output of the first exchanger 1 and according to the flow rate value of the heat transfer liquid F1. In other words, the ratio between the temperature of the heat transfer liquid F1 at the output of the first exchanger 1 and the temperature of the coolant fluid in the first exchanger 1 takes into account the thermal efficiency of the first exchanger 1. This efficiency can be characterized for different flow rates and stored in a table in the memory of the electronic control unit.

[0142] The step (ii2) of determining the pressure set point C_P1 of the coolant fluid in the first exchanger 1 from the temperature set point C_T1 is based on the characteristic saturation curve of the coolant fluid used. Figure 5 As shown, the pressure of the coolant fluid is associated with each condensation temperature of the coolant fluid.

[0143] Step (ii) comprises the following sub-steps:

[0144] (ii3) Controlling the rotation speed N of the compressor 7 so that the pressure P1 of the coolant fluid in the first exchanger 1 is equal to the determined pressure set point C_P1 .

[0145] Controlling the rotation speed N of the compressor 7 makes it possible to control the pressure of the coolant fluid in the first exchanger 1. In general, an increase in the rotation speed of the compressor 7 makes it possible to increase the pressure P1 of the coolant fluid in the first exchanger 1.

[0146] The pressure P1 of the coolant fluid in the first exchanger 1 can be measured by a measuring sensor located at the input of the first exchanger 1. The measuring sensor can also be located in the first exchanger 1.

[0147] Step (i) comprises the following sub-steps:

[0148] (i3) Determining the delivery pressure set point C_Pr_d of the compressor 7 from the determined pressure set point C_P1 of the coolant fluid in the first exchanger 1 .

[0149] Step (ii) comprises the following sub-steps:

[0150] (ii1) Controlling the rotation speed N of the compressor 7 so that the delivery pressure Pr_d of the compressor 7 is equal to the determined delivery pressure set point C_Pr_d.

[0151] According to an embodiment of the method, the pressure of the coolant fluid in the first exchanger 1 is substantially equal to the delivery pressure Pr_d of the compressor 7. In other words, the load losses between the output 7b of the compressor 7 and the first exchanger 1 are therefore negligible and the pressure set point C_P1 of the coolant fluid in the first exchanger 1 is transformed into the delivery pressure set point C_Pr_d of the compressor 7.

[0152] According to another embodiment of the method, the pressure P1 of the coolant fluid in the first exchanger 1 is estimated, for example from a measurement of the delivery pressure Pr_d of the compressor 7. In other words, the difference between the delivery pressure Pr_d of the compressor 7 and the pressure P1 of the coolant fluid in the first exchanger 1 is taken into account.

[0153] Figure 2 A second embodiment of a heat regulation system 100 is shown. The coolant fluid circuit 10 comprises a first branch B located in parallel with the second expansion valve 32 and the third heat exchanger 3 . The first branch B comprises the third expansion valve 33 and the fourth heat exchanger 4 .

[0154] In other words, the heat regulation system 100 comprises a first branch B which fluidically connects a first connection point 11 on the main loop A downstream of the second exchanger 2 and upstream of the second expansion valve 32 with a second connection point 12 on the main loop A downstream of the third exchanger 3 and upstream of the compressor 7. The first branch B comprises a third expansion valve 33. The third expansion valve 33 is located upstream of the fourth exchanger 4.

[0155] In the example shown, the fourth heat exchanger 4 is configured to exchange heat with the air flow Fi in the passenger space of the vehicle. The fourth heat exchanger 4 is located in the heating, ventilation and / or air conditioning device. The first heat exchanger 1 is located downstream of the fourth heat exchanger 4 in the flow direction of the interior air flow Fi. The fourth exchanger 4 makes it possible to cool the passenger space, while the first exchanger 1 makes it possible to heat the passenger space.

[0156] Figure 4 A variation of the second embodiment is shown. According to this variation, the heat transfer liquid F1 is a heat transfer liquid configured to circulate in a fifth heat exchanger 5 configured to exchange heat with an air flow Fi in the vehicle passenger space.

[0157] The fifth heat exchanger 5 is located on the second heat transfer liquid circuit 21. The passenger space is thus heated indirectly, since the heat of condensation of the coolant fluid is first transferred to the heat transfer liquid of the circuit 21, and the heat of the heat transfer liquid is then 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 function in the same manner as Figure 2The heat transfer liquid circuit 21 for heating the passenger space and the heat transfer liquid circuit 20 for thermal connection with the element 25 of the transmission chain are separate, i.e. they are not connected. The fifth exchanger 5 is located in the heating, ventilation and / or air conditioning device. In the embodiment in which the fourth exchanger 4 is present, the fifth exchanger 5 is located downstream of the fourth exchanger 4 in the flow direction of the interior air flow Fi.

[0158] Figure 3 A third embodiment of a heat regulation system 100 is shown. The coolant fluid circuit 10 comprises a second branch C which allows the coolant fluid at the output of the compressor 7 to reach the third exchanger 3 by bypassing the first exchanger 1, the second exchanger 2 and the second expansion valve 32. The second branch C comprises a fourth expansion valve 34. The fourth expansion valve 34 is configured to change the passage cross section of the coolant fluid in the second branch c.

[0159] In other words, the heat regulation system 100 comprises a second branch C, which fluidically connects a third connection point 13 on the main loop A, downstream of the compressor 7 and upstream of the first exchanger 1, with a fourth connection point 14 on the main loop A, downstream of the second expansion valve 32 and upstream of the third exchanger 3. The second branch C comprises a fourth expansion device 34. The fourth expansion valve 34 is configured to change the passage cross section of the coolant fluid in the second branch c.

[0160] In this embodiment, the high-pressure refrigerant fluid flow at the output end of the compressor 7 is divided into a first fluid flow circulating in the main loop A and a second fluid flow circulating in the second branch C, wherein the two fluid flows are divided at the third connection point 13. The first refrigerant fluid flow circulating in the main loop A is partially condensed in the first exchanger 1 by generating heat to the heat transfer liquid F1, it undergoes partial expansion in the first expansion valve 31, and condenses in the second exchanger 2. If the third expansion valve 33 is in the closed position, since the flow in the first branch B is zero, all the refrigerant fluid flow flowing out of the second exchanger passes through the second expansion valve 32. The first refrigerant fluid flow is therefore expanded by the second expansion valve 32 and reaches the fourth connection point 14.

[0161] The second coolant fluid flow circulating in the second branch C undergoes expansion at the fourth expansion valve 34. The second coolant fluid flow is in a superheated vapor state. The superheated vapor flow circulating in the second branch C is mixed with the liquid coolant fluid or two-phase fluid flow circulating in the main loop a at the fourth connection point 14. The superheated vapor flow circulating in the second branch C is controlled so that the obtained mixture is completely in gaseous form, that is, also in superheated vapor form, at the output of the third exchanger 3. Therefore, the reliability of the compressor 7 is guaranteed.

[0162] When the third expansion valve 33 is in the open position, the first refrigerant fluid flow circulating in the main loop A downstream of the second exchanger 2 is divided at the first connection point 11 into a third fluid flow circulating in the main loop A to reach the second expansion unit 32 and a fourth fluid flow circulating in the first branch B to reach the fourth heat exchanger 4. In this case, the refrigerant fluid at the output of the fourth exchanger 4 reaches the refrigerant fluid flow from the third exchanger 3 at the second connection point 12. The total flow of the refrigerant fluid reaches the input 7a of the compressor 7, and a new cycle begins.

[0163] exist Figure 3 In the third embodiment shown, the main loop A of the coolant fluid circuit 10 comprises a fifth expansion valve 35 located downstream of the compressor 7 and upstream of the first exchanger 1. The coolant fluid is expanded by the fifth expansion valve 35, and the pressure of the coolant fluid in the first exchanger 1 is lower than the delivery pressure Pr_d of the compressor 7. As the delivery pressure of the compressor 7 increases, the energy received by the coolant fluid itself increases, which makes it possible to increase the total thermal power supplied by the heat conditioning system.

[0164] The pressure P1 of the coolant fluid in the first exchanger 1 is estimated from the pressure measurement of the coolant fluid at the output of the fifth expansion valve 35 .

[0165] according to Figure 4 In a variation of the present invention, the main loop A of the coolant fluid comprises a coolant fluid accumulation device 8' located downstream of the third exchanger 3 and upstream of the compressor 7. The device 8' for accumulating the coolant fluid is a coolant fluid accumulation device. This variation can also be applied to the first embodiment and the third embodiment.

[0166] Furthermore, the second branch C may be present without the first branch B. This variant is not shown.

Claims

1. A control method for controlling a heat regulation system (100), the heat regulation system (100) comprising: - a heat transfer liquid circuit (20), configured to circulate a heat transfer liquid: - A coolant fluid circuit (10), comprising in order in the flow direction of the coolant fluid: --Compressor (7); a first heat exchanger (1) configured to supply a first thermal power (Pw1) to the heat transfer liquid (F1); - a first expansion valve (31); a second heat exchanger (2) arranged jointly on the coolant fluid circuit (10) and the heat transfer liquid circuit (20) in order to supply a second thermal power (Pw2) to the heat transfer liquid; - Second expansion valve (32); - a third heat exchanger (3); The control method comprises the following steps: (i) receiving a total thermal power set point (C_Pw) to be supplied, the total thermal power set point (C_Pw) to be supplied being the sum of a first thermal power set point (C_Pw1) to be supplied to the heat transfer liquid (F1) in the first exchanger (1) and a second thermal power set point (C_Pw2) to be supplied to the heat transfer liquid in the second exchanger (2); (ii) controlling the pressure of the coolant fluid in the first exchanger (1) so that the sum of the supplied first thermal power (Pw1) and the supplied second thermal power (Pw2) is equal to the total thermal power set point (C_Pw) to be supplied; and (iii) controlling the through cross section of the first expansion valve (31) so that the second thermal power (Pw2) supplied by the second exchanger (2) is equal to the second thermal power set point (C_Pw2) to be supplied.

2. The control method according to claim 1, wherein: Step (ii) comprises the following sub-steps: (ii1) determining a temperature set point (C_T1) of the coolant fluid in the first exchanger (1) based on the first thermal power set point (C_Pw1) and the flow set point (C_Q1) of the heat transfer liquid (F1); (ii2) determining a pressure set point (C_P1) of the coolant fluid in the first exchanger (1) based on the determined temperature set point (C_T1).

3. A control method according to the preceding claim, wherein: Step (ii) comprises the following sub-steps: (ii3) Controlling the rotation speed (N) of the compressor (7) so that the pressure (P1) of the coolant fluid in the first exchanger (1) is equal to the determined pressure set point (C_P1).

4. The control method according to claim 2 or 3, wherein: The compressor (7) is configured to bring the coolant fluid from a suction pressure (Pr_s) to a delivery pressure (Pr_d), and wherein step (i) comprises the following sub-steps: (i3) Determining a delivery pressure set point (C_Pr_d) of the compressor (7) as a function of the determined pressure set point (C_P1) of the coolant fluid in the first exchanger (1).

5. The control method according to claim 4, wherein: Step (ii) comprises the following sub-steps: (ii1) controlling the rotation speed (N) of the compressor (7) so that the delivery pressure (Pr_d) of the compressor (7) is equal to the determined delivery pressure set point (C_Pr_d).

6. The method according to any one of claims 1 to 5, wherein: The heat transfer fluid (F1) is an air flow (Fi) in the passenger space of a motor vehicle.

7. The method according to any one of claims 1 to 5, wherein: The heat transfer liquid (F1) is a heat transfer liquid configured to circulate in a fifth heat exchanger (5), and the fifth heat exchanger (5) is configured to perform heat exchange with an air flow (Fi) in a passenger space of the vehicle.

8. A method according to any one of the preceding claims, wherein: The second heat exchanger (2) is thermally coupled to an element (25) of a traction chain of the vehicle via the heat transfer fluid of the heat transfer fluid circuit (20).

9. A method according to any one of the preceding claims, wherein: The third heat exchanger (3) is thermally coupled to an element (25) of a traction chain of the vehicle via the heat transfer fluid of the heat transfer fluid circuit (20).

10. A heat regulation system (100), comprising: - a heat transfer liquid circuit (20), configured to circulate a heat transfer liquid: - A coolant fluid circuit (10) comprising: --The main loop (A) includes, in order along the flow direction of the coolant fluid: ---Compressor (7); ---a first heat exchanger (1) configured to supply a first thermal power (Pw1) to a heat transfer liquid (F1); ---First expansion valve (31); ---a second heat exchanger (2) arranged jointly on the coolant fluid circuit (10) and the heat transfer liquid circuit (20) for supplying a second thermal power (Pw2) to the heat transfer liquid; --- Second expansion valve (32); ---The third heat exchanger (3); An electronic control unit (50) configured to implement a control method according to any one of the preceding claims.

11. The heat conditioning system (100) according to claim 10, wherein: The coolant fluid circuit (10) comprises a first branch (B) positioned in parallel with the second expansion valve (32) and the third heat exchanger (3), the first branch (B) comprising a third expansion valve (33) and a fourth heat exchanger (4), and wherein the fourth heat exchanger (4) is configured to exchange heat with an air flow (Fi) in a passenger space of the vehicle.

12. The heat conditioning system (100) according to claim 10 or 11, wherein: The coolant fluid circuit (10) comprises a second branch (C) allowing the coolant fluid at the output of the compressor (7) to reach the third exchanger (3) by bypassing the first exchanger (1), the second exchanger (2) and the second expansion valve (32), the second branch (C) comprising a fourth expansion valve (34).

Images