Methods for controlling thermal regulation systems

Abstract

A method for controlling a thermal conditioning system (100) is disclosed, the thermal conditioning system comprising: a heat transfer liquid circuit (20); a refrigerant circuit (10) having: a compressor (7); a first heat exchanger (1) supplying a first thermal power (Pw1) to a 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); and a third heat exchanger (3), the control method comprising the steps of: (i) receiving a total of the total thermal power to be supplied. The total heat power setpoint (C_Pw) is the sum of the first heat power setpoint (C_Pw1) of the first heat exchanger (1) and the second heat power setpoint (C_Pw2) of the second heat exchanger (2). (ii) The pressure of the refrigerant in the first heat exchanger (1) is controlled so that the total heat power supplied is equal to the total heat power setpoint (C_Pw). (iii) The flow area of ​​the first expansion valve (31) is controlled so that the second heat power supplied (Pw2) is equal to the second heat power setpoint (C_Pw2).

Description

Technical Field

[0001] This invention relates to the field of thermal regulation systems. This type of thermal regulation system is particularly suitable for equipping motor vehicles. When the vehicle's traction chain is electric, these systems allow for thermal regulation of different components of the vehicle, such as the passenger compartment or the energy storage battery. Heat exchange is primarily controlled by the compression and expansion of the coolant fluid within multiple heat exchangers. Background Technology

[0002] Thermal control systems typically use a coolant fluid loop and a heat transfer fluid loop that exchanges heat with the coolant fluid. Such systems are therefore referred to as indirect. The compressor ensures the passage of high-pressure coolant fluid.

[0003] It is known that the following components are positioned in series in the coolant fluid circuit: a first heat exchanger, which ensures heating of the airflow to the passenger compartment of the vehicle; a second heat exchanger, which heats elements of the vehicle's traction chain; and a third heat exchanger, which further cools these elements of the vehicle's traction chain. The elements of the traction chain are, for example, an electrical energy storage battery. The second and third exchangers are located, for example, jointly on the coolant fluid circuit and the heat transfer fluid circuit. The heat transfer fluid flowing in the circuit ensures heat exchange with the elements of the traction chain. Depending on the operating mode, heat can therefore be supplied to the elements of the vehicle's traction chain to heat them, or heat can be recovered from them to, for example, transfer heat to the airflow supplied to the passenger compartment to heat it. In a particular operating mode, the air in the passenger compartment is heated by the first heat exchanger, while the heating of the heat transfer fluid is ensured at the second heat exchanger.

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

[0005] The purpose of this disclosure is to provide a control method that enables reliable control of the total supplied heat power and its distribution between two heat exchangers. Summary of the Invention

[0006] Therefore, the present invention proposes a method for controlling a thermal regulation system, the thermal regulation system comprising:

[0007] - Heat transfer fluid circuit, configured to allow heat transfer fluid to flow;

[0008] - The coolant fluid circuit, in the direction of coolant fluid flow, includes, in sequence:

[0009] --compressor;

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

[0011] --First expansion valve;

[0012] --A second heat exchanger is arranged together on the coolant fluid circuit and the heat transfer liquid circuit to supply a second heat power to the heat transfer liquid;

[0013] --Second expansion valve;

[0014] --Third heat exchanger;

[0015] The control method includes the following steps:

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

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

[0018] This partial expansion allows for a reduction in the condensation temperature in the second heat exchanger, thereby regulating the distribution of 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 achieved.

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

[0020] According to one embodiment, the thermal regulation system is a thermal regulation system for motor vehicles.

[0021] The cross-sectional area of ​​the first expansion valve is controlled by a proportional-integral regulator.

[0022] The cross-sectional area of ​​the second expansion valve is controlled by a proportional-integral regulator.

[0023] This type of regulator ensures reliable regulation while maintaining simplicity in programming and adjustment.

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

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

[0026] Preferably, in step (ii1), the temperature setpoint of the coolant fluid in the first exchanger is also determined based on the input temperature of the coolant fluid in the first exchanger.

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

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

[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 bring the coolant fluid from the suction pressure to the delivery pressure.

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

[0032] The compressor's delivery pressure setpoint is determined based on the established pressure setpoint of the coolant fluid in the first exchanger.

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

[0034] (ii1) Control the compressor speed so that the compressor delivery pressure is equal to the determined delivery pressure setpoint.

[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, based on measurements of the compressor's delivery pressure.

[0037] According to one embodiment of the method, the heat transfer fluid is the airflow within the passenger compartment of a motor vehicle.

[0038] According to another embodiment of the method, the heat transfer fluid is configured to circulate in a fifth heat exchanger, which is configured to exchange heat with the airflow within the passenger compartment of the vehicle.

[0039] According to one aspect of the method, the second heat exchanger is thermally connected to the components of the vehicle's traction chain via a heat transfer fluid in a heat transfer fluid circuit.

[0040] Therefore, the second heat exchanger enables the supply of thermal power to the components of the vehicle's traction chain, i.e., heating the components to increase their temperature.

[0041] According to an embodiment of the method, the third heat exchanger is thermally connected to the components of the vehicle's traction chain via the heat transfer fluid in the heat transfer fluid circuit.

[0042] Therefore, the third heat exchanger allows heat to be absorbed from the components of the vehicle's traction chain in order to keep its temperature within an acceptable range, or to transfer the absorbed heat to another unit.

[0043] Components of an electric traction chain include, for example, the electric traction motor of a vehicle.

[0044] As a variation or supplement, the components of an electric traction chain include an electronic module for controlling an electric traction motor of the vehicle.

[0045] As a variation or supplement, electric traction chains also include energy storage batteries.

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

[0047] - Heat transfer fluid circuit, configured to allow heat transfer fluid to flow;

[0048] - Coolant fluid circuit, including:

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

[0050] ---compressor;

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

[0052] ---First expansion valve;

[0053] ---The second heat exchanger is arranged together on the coolant fluid circuit and the heat transfer liquid circuit to supply a second heat power to the heat transfer liquid;

[0054] ---Second expansion valve;

[0055] ---Third heat exchanger;

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

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

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

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

[0060] The thermal control system includes a first branch that fluidly connects a first connection point on the main loop, located downstream of the second exchanger and upstream of the second expansion valve, to a second connection point on the main loop, located downstream of the third exchanger and upstream of the compressor. The first branch includes a third expansion valve.

[0061] According to one embodiment of the thermal control system, the fourth heat exchanger is configured to exchange heat with the airflow within the passenger compartment of the vehicle.

[0062] According to one embodiment, the coolant fluid circuit includes a second branch that allows coolant fluid at the compressor output to reach a third exchanger by bypassing a first exchanger, a second exchanger, and a second expansion valve. The second branch includes a fourth expansion valve.

[0063] The thermal control system includes a second branch that fluidly connects a third connection point on the main loop, located downstream of the compressor and upstream of the first exchanger, to a fourth connection point on the main loop, located downstream of the second expansion valve and upstream of the third exchanger. The second branch includes a fourth expansion device.

[0064] According to one embodiment, the main loop of the coolant fluid circuit includes a fifth expansion valve located downstream of the compressor and upstream of the first exchanger, through which the coolant fluid expands, 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 based on the measured pressure of the coolant fluid at the output of the fifth expansion valve. Attached Figure Description

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

[0067] [ Figure 1 [Illustration] is a schematic diagram of a thermal regulation system according to a first embodiment, wherein the control method according to the invention is implemented;

[0068] [ Figure 2 [Illustration] is a schematic diagram of a thermal regulation system according to a second embodiment, wherein the control method according to the invention is implemented;

[0069] [ Figure 3 ]yes Figure 2 A schematic diagram of a variation of the thermal control system;

[0070] [ Figure 4 ]yes Figure 2 A schematic diagram of another variation of the thermal control system;

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

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

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

[0074] In the following description, the term "first element upstream of second element" means that, relative to the direction of fluid flow or travel, the first element is located before the second element. Similarly, the expression "first element downstream of second element" means that, relative to the direction of fluid flow or travel, the first element is located after the second element. In the case of a coolant fluid circuit, the term "first element upstream of second element" means that the coolant fluid travels successively along the first element and then the second element without passing through the compression unit. In other words, the coolant fluid leaves the compression unit, passes through one or optionally multiple elements, then through the first element, then through the second element, and then optionally returns to the compression unit after having passed through 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 specified subsystem includes a given element, this does not preclude the presence of other elements in that subsystem.

[0077] In the thermal control system 100, the electronic control unit 50 receives information from various sensors (not shown), particularly the characteristics of the coolant fluid at various points on the measurement loop. The electronic control unit also receives setpoints from vehicle passengers, such as the desired temperature within the passenger compartment. The electronic control unit executes control laws that allow control of different actuators to control the thermal control system 100, thereby ensuring that the setpoints are received. The electronic control unit 50 specifically implements the method according to the invention.

[0078] The compressor 7 can be an electric compressor, i.e., a compressor whose movable parts are driven by an electric motor. The compressor 7 includes a side for drawing in low-pressure coolant fluid, also referred to as the input end 7a of the compressor, and a side for delivering high-pressure coolant fluid, also referred to as the output end 7b of the compressor 7. The compressor 7 is configured to bring the coolant fluid from the suction pressure Pr_s to the 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. Moving parts inside the compressor 7 cause the coolant fluid to change from the low-pressure state on the input side 7a to the high-pressure state on the output side 7b. After expanding in one or more expansion devices, the coolant fluid returns to the input section 7a of the compressor 7 and begins a new thermodynamic cycle.

[0080] The coolant fluid circuit 10 forms a closed loop through which coolant fluid can flow. When the coolant fluid circuit 10 is in normal operating condition, i.e., without malfunction or leakage, it is sealed. Each connection point of the circuit 10 allows coolant fluid to enter one or more circuit sections that meet at that connection point. Coolant fluid is distributed between the circuit sections that meet at the connection point by adjusting the opening or closing of a shut-off valve, check valve, or expansion device included on each branch. In other words, each connection point is a means of changing the direction of the coolant fluid arriving at that connection point. Therefore, shut-off valves and check valves allow coolant fluid to be selectively directed into different branches of the coolant fluid circuit to ensure different operating modes, which will be described below.

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

[0082] "Internal airflow Fi" refers to the airflow that flows into the passenger space of a motor vehicle. This internal airflow can circulate within a device commonly referred to as "HVAC" for heating, ventilation, and / or air conditioning. Such devices are not shown in the various diagrams.

[0083] Figure 1A first embodiment of the thermal regulation system 100 includes:

[0084] - A heat transfer fluid circuit 20 is constructed to allow the heat transfer fluid to circulate;

[0085] - Coolant fluid circuit 10, including:

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

[0087] ---Compressor 7;

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

[0089] ---First expansion valve 31;

[0090] ---The second heat exchanger 2 is arranged together on the coolant fluid circuit 10 and the heat transfer liquid circuit 20 to supply the second thermal power Pw2 to the heat transfer liquid;

[0091] ---Second expansion valve 32;

[0092] ---Third heat exchanger 3;

[0093] - Electronic control unit 50 is configured to implement the control method, which will be described in detail below.

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

[0095] The first heat power Pw1 supplied is the heat 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 two-fluid exchanger. In other words, the second heat exchanger 2 includes a first compartment through which a coolant fluid passes and a second compartment through which a heat transfer liquid passes. These two compartments are sealed and allow for heat exchange. The two-fluid exchanger 2 includes an inlet 2a and an outlet 2b for the coolant fluid, and inlets and outlets for the heat transfer liquid, which are not labeled in the illustrative figures. The second exchanger 2 is, for example, a plate exchanger.

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

[0098] The second heat power Pw2 supplied is the heat power of the heat transfer liquid in the heat transfer liquid circuit 20 within the second heat exchanger 2, which is supplied by the coolant fluid.

[0099] The third heat exchanger is also a two-fluid exchanger.

[0100] Each expansion valve is a device for expanding the coolant fluid. Each expansion valve allows for adjustment of the degree of expansion of the coolant fluid as it passes through the valve. Each expansion valve is configured to change the cross-sectional area through which the coolant fluid flows. "Cross-sectional area" refers to the surface area through which the coolant fluid flows as it passes through the expansion valve.

[0101] Each expansion valve includes a coolant fluid inlet and a coolant fluid outlet. The inlet and outlet are fluidly connected via a channel. A movable baffle allows control over the cross-sectional area of ​​the channel, i.e., the surface area of ​​the channel supplied with coolant fluid. The expansion valve is, for example, an electronic expansion valve, in which 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 can be measured and adjusted in real time to obtain a position setpoint. The cross-sectional area of ​​the coolant fluid can be continuously adjusted between a closed position and a maximum open position. The electronic control module for each expansion valve can be integrated into the corresponding expansion valve. According to one variant, the electronic control unit 50 can also ensure 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 this embodiment, the heat transfer fluid F1 is the internal airflow F1 flowing to the passenger compartment of the motor vehicle. A first heat exchanger 1 is located within a heating, ventilation, and / or air conditioning system. Therefore, the first heat exchanger 1 allows for heating of the vehicle's passenger compartment.

[0104] The second heat exchanger 2 is thermally connected to the vehicle's traction chain element 25 via the heat transfer fluid in the heat transfer fluid circuit 20. Therefore, the second heat exchanger 2 allows for the supply of thermal power to the vehicle's traction chain element 25, i.e., heating the element to increase its temperature. Heating of the traction chain element 25 can be activated, for example, during the operation of the vehicle at a negative ambient temperature; the element is, for example, an energy storage battery.

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

[0106] Element 25 of the electric traction chain includes, for example, an electric traction motor of a vehicle. As a variation, or supplement, element 25 of the electric traction chain includes an energy storage battery. Also as a variation, or supplement, element 25 of the electric traction chain includes an electronic module for controlling the electric traction motor of the vehicle.

[0107] The third heat exchanger 3 is thermally connected to the components 25 of the vehicle's traction chain via the heat transfer fluid in the heat transfer fluid circuit 20.

[0108] Therefore, the third heat exchanger 3 allows heat to be absorbed from the elements 25 of the vehicle's traction chain to maintain their temperature within acceptable limits, or the absorbed heat to be transferred to another unit. The combined action of the second exchanger 2 and the third exchanger 3 ensures thermal regulation of the elements 25 of the traction chain according to various operating modes. The heat transfer fluid circuit 20 is not described in detail and is indicated by dashed lines at the third exchanger 3 and the second exchanger 2. For simplicity and to avoid crossing between lines of different circuits, circuit 20 is represented as two distinct parts.

[0109] The heat transfer fluid circuit 20 includes at least one flow pump (not shown) that allows the heat transfer fluid to flow through the circuit 20.

[0110] according to Figure 1 In one embodiment, the main loop A of the coolant fluid includes a coolant flow 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 regulation system 100, the accumulation device 8 allows for compensation of mass variations in the coolant fluid flowing in the loop 10.

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

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

[0113] A heat transfer fluid circuit 20 is constructed to allow the heat transfer fluid to circulate.

[0114] The coolant fluid circuit 10, in the direction of coolant fluid flow, includes, in sequence:

[0115] Compressor 7;

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

[0117] First expansion valve 31;

[0118] The second heat exchanger 2 is arranged together on the coolant fluid circuit 10 and the heat transfer liquid circuit 20 to supply the second thermal power Pw2 to the heat transfer liquid;

[0119] Second expansion valve 32;

[0120] Third heat exchanger 3.

[0121] The control method includes the following steps:

[0122] (i) Receive the total heat power setpoint C_Pw to be supplied, which is the sum of the first heat power setpoint C_Pw1 to be supplied to the heat transfer liquid F1 in the first exchanger 1 and the second heat power setpoint C_Pw2 to be supplied to the heat transfer liquid in the second exchanger 2; (ii) Control the pressure of the coolant fluid in the first exchanger 1 such that the sum of the first heat power Pw1 and the second heat power Pw2 supplied is equal to the total heat power setpoint C_Pw to be supplied; and (iii) Control the cross-section of the first expansion valve 31 such that the second heat power Pw2 supplied by the second exchanger 2 is equal to the second heat power setpoint C_Pw2 to be supplied.

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

[0124] This partial expansion allows for a reduction in the condensation temperature in the second heat exchanger 2, thereby regulating the distribution of 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 achieved.

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

[0126] For example, a total thermal power setpoint C_Pw can be issued, which has a distribution setpoint between the first and second thermal powers. In other words, the total power to be supplied is known, and the portion of that total power that must be allocated to the first thermal power Pw1 and the second thermal power Pw2 is also known.

[0127] Alternatively, the first setpoint C_Pw1 of the first thermal power can be received directly, or the second setpoint C_Pw2 of the second thermal power can be received.

[0128] Figure 5 This shows that when the method described here is implemented, Figure 1 Operation of the thermal control system 100.

[0129] This figure illustrates the thermodynamic state of the coolant fluid during the thermodynamic cycle. The values ​​on the x-axis are the enthalpy H of the coolant fluid. The values ​​on the y-axis are the coolant fluid pressure P on a logarithmic scale. Curve S is the characteristic saturation curve of the coolant fluid used. The graphical region 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 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 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 essentially equal to the enthalpy and pressure at 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 output 1b of the first exchanger 1 (marked by reference Q1) represents the first heat power Pw1 supplied. The first expansion valve 31 performs partial expansion of the coolant fluid, causing the pressure of the coolant fluid in the second exchanger 2 to be 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 second heat power Pw2 supplied. The expansion level provided by the first expansion valve 31 (schematically shown by the vertical distance between points A1b and A2a) allows the condensation temperature of the coolant fluid in the second exchanger 2 to be adjusted, thereby regulating the second thermal power Pw2.

[0131] The second expansion valve 32 expands the coolant fluid until it reaches 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 inlet 7a of the compressor 7. The change in enthalpy between points A32b and A7a represents the heat power absorbed by the coolant fluid within the third exchanger 3, i.e., during the passage from the inlet 3a to the outlet 3b of the third exchanger 3.

[0132] The cross-sectional area of ​​the first expansion valve 31 is controlled by a proportional-integral (PI) controller. Similarly, the cross-sectional area of ​​the second expansion valve 32 is controlled by a PI controller. This type of controller ensures reliable regulation while maintaining simple programming and adjustment. It should be understood that other types of controllers can be used.

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

[0134] (ii1) Determine the temperature setpoint C_T1 of the coolant fluid in the first exchanger 1 based on the first thermal power setpoint C_Pw1 and the flow rate setpoint C_Q1 of the heat transfer liquid F1; (ii2) Determine the pressure setpoint C_P1 of the coolant fluid in the first exchanger 1 from the determined temperature setpoint C_T1.

[0135] Preferably, in step (ii1), the temperature setpoint C_T1 of the coolant fluid in the first exchanger 1 is also determined based on the input temperature T1_i of the coolant fluid in the first exchanger 1.

[0136] The step (ii1) of determining the temperature setpoint 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 setpoint of the coolant fluid can be obtained from the temperature that the heat transfer liquid F1 needs to reach.

[0138] The first heat power Pw_1 supplied 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 fluid F1, i.e., the temperature before heat exchange occurs in the first exchanger 1, is known, the target output temperature of the heat transfer fluid F1 can be determined. Therefore, the set temperature C_T1 of the coolant fluid can be 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 based on the flow rate of the heat transfer liquid F1. For example, a target temperature value for the coolant fluid in the first exchanger 1 can be tabulated based on the temperature of the heat transfer liquid at the output of the first exchanger 1 and 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 is stored in a table in the memory of the electronic control unit.

[0142] Step (ii2) of determining the pressure setpoint C_P1 of the coolant fluid in the first exchanger 1 from the temperature setpoint C_T1 is based on the characteristic saturation curve of the coolant fluid used. For example... Figure 5 As shown, the pressure of the coolant fluid is related to each condensation temperature of the coolant fluid.

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

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

[0145] Controlling the speed N of compressor 7 allows control over the pressure of the coolant fluid in the first exchanger 1. Generally, increasing the speed of compressor 7 increases 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 may also be located within the first exchanger 1.

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

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

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

[0150] (ii1) Control the speed N of compressor 7 so that the delivery pressure Pr_d of compressor 7 is equal to the determined delivery pressure setpoint 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 loss between the output section 7b of the compressor 7 and the first exchanger 1 can therefore be ignored, and the pressure setpoint C_P1 of the coolant fluid in the first exchanger 1 is transformed into the delivery pressure setpoint 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, based on 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 the thermal regulation system 100 is shown. The coolant fluid circuit 10 includes a first branch B positioned in parallel with the second expansion valve 32 and the third heat exchanger 3. The first branch B includes a third expansion valve 33 and a fourth heat exchanger 4.

[0154] In other words, the thermal control system 100 includes a first branch B that fluidly connects a first connection point 11 on the main loop A, located downstream of the second exchanger 2 and upstream of the second expansion valve 32, to a second connection point 12 on the main loop A, located downstream of the third exchanger 3 and upstream of the compressor 7. The first branch B includes a third expansion valve 33. The third expansion valve 33 is located upstream of the fourth exchanger 4.

[0155] In the example shown, a fourth heat exchanger 4 is configured to exchange heat with the airflow Fi within the vehicle's passenger compartment. The fourth heat exchanger 4 is located within a heating, ventilation, and / or air conditioning system. A first heat exchanger 1 is located downstream of the fourth heat exchanger 4 in the direction of the internal airflow Fi. The fourth heat exchanger 4 allows for cooling of the passenger compartment, while the first heat exchanger 1 allows for heating of the passenger compartment.

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

[0157] The fifth heat exchanger 5 is located on the second heat transfer fluid loop 21. The passenger space is thus indirectly heated because the heat of condensation of the coolant fluid is first transferred to the heat transfer fluid in loop 21, and then the heat of the heat transfer fluid is transferred to the internal airflow Fi at the fifth heat exchanger 5. A pump (not shown) allows the heat transfer fluid to circulate in loop 21. The other heat exchangers function similarly to... Figure 2The same as in the embodiments. The heat transfer fluid circuit 21 for heating the passenger space and the heat transfer fluid circuit 20 for thermally connecting with the element 25 of the drive chain are separate, i.e., they are not connected. The fifth exchanger 5 is located in the heating, ventilation and / or air conditioning equipment. In embodiments where a fourth exchanger 4 is present, the fifth exchanger 5 is located downstream of the fourth exchanger 4 in the flow direction of the internal airflow Fi.

[0158] Figure 3 A third embodiment of the thermal regulation system 100 is shown. The coolant fluid circuit 10 includes a second branch C that allows coolant fluid at the output of the compressor 7 to bypass the first exchanger 1, the second exchanger 2, and the second expansion valve 32 to reach the third exchanger 3. The second branch C includes a fourth expansion valve 34. The fourth expansion valve 34 is configured to change the cross-sectional area of ​​the coolant fluid in the second branch C.

[0159] In other words, the thermal regulation system 100 includes a second branch C that fluidly connects a third connection point 13 on the main loop A, located downstream of the compressor 7 and upstream of the first exchanger 1, to a fourth connection point 14 on the main loop A, located downstream of the second expansion valve 32 and upstream of the third exchanger 3. The second branch C includes a fourth expansion device 34. The fourth expansion valve 34 is configured to change the cross-sectional area of ​​the coolant fluid in the second branch C.

[0160] In this embodiment, the high-pressure coolant fluid flow at the output of compressor 7 is divided into a first fluid flow flowing in the main loop A and a second fluid flow flowing in the second branch C, wherein the two fluid flows are divided at the third connection point 13. The first coolant fluid flow flowing in the main loop A partially condenses in the first exchanger 1 by generating heat to the heat transfer liquid F1, 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 rate in the first branch B is zero, all coolant fluid flow from the second exchanger passes through the second expansion valve 32. The first coolant fluid flow is thus expanded by the second expansion valve 32 and reaches the fourth connection point 14.

[0161] The second coolant fluid flowing in the second branch C undergoes expansion at the fourth expansion valve 34. The second coolant fluid is in a superheated vapor state. The superheated vapor flowing in the second branch C mixes with the liquid coolant fluid or two-phase fluid flowing in the main loop a at the fourth connection point 14. The superheated vapor flowing in the second branch C is controlled so that the resulting mixture is entirely in a gaseous form at the output of the third exchanger 3, i.e., also in superheated vapor form. This ensures the reliability of the compressor 7.

[0162] When the third expansion valve 33 is in the open position, the first coolant fluid flow flowing in the main loop A downstream of the second heat exchanger 2 is divided at the first connection point 11 into a third fluid flow flowing in the main loop A to reach the second expansion unit 32 and a fourth fluid flow flowing in the first branch B to reach the fourth heat exchanger 4. In this case, the coolant fluid at the output of the fourth heat exchanger 4 reaches the coolant fluid flow from the third heat exchanger 3 at the second connection point 12. The total flow rate of the coolant 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 includes a fifth expansion valve 35 located downstream of the compressor 7 and upstream of the first exchanger 1. The coolant fluid expands through 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 allows for an increase in the total thermal power supplied by the thermal regulation system.

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

[0165] according to Figure 4 In a variant, the main loop A of the coolant fluid includes a coolant flow accumulation device 8' located downstream of the third exchanger 3 and upstream of the compressor 7. The device 8' for collecting the coolant fluid is a coolant flow accumulation unit. This variant can also be applied to the first and third embodiments.

[0166] Furthermore, the second branch C can exist even if the first branch B does not exist. This variant is not shown.

Claims

1. A control method for controlling a thermal regulation system (100), the thermal regulation system (100) comprising: - Heat transfer fluid loop (20), configured to allow heat transfer fluid to flow: - The coolant fluid circuit (10) includes, in sequence, the following components in the direction of coolant fluid flow: --Compressor (7), --The first heat exchanger (1) is configured to supply a first thermal power (Pw1) to the heat transfer liquid (F1). --First expansion valve (31), --A second heat exchanger (2) is arranged together on the coolant fluid circuit (10) and the heat transfer liquid circuit (20) to supply a second thermal power (Pw2) to the heat transfer liquid. --Second expansion valve (32), --Third heat exchanger (3), The control method includes the following steps: (i) Receive the total heat power setpoint (C_Pw) to be supplied, which is the sum of the first heat power setpoint (C_Pw1) to be supplied to the heat transfer liquid (F1) in the first heat exchanger (1) and the second heat power setpoint (C_Pw2) to be supplied to the heat transfer liquid in the second heat exchanger (2). (ii) Controlling the pressure of the coolant fluid in the first heat exchanger (1) such that the sum of the supplied first heat power (Pw1) and the supplied second heat power (Pw2) equals the total heat power setpoint (C_Pw) to be supplied, and (iii) Control the cross-section of the first expansion valve (31) such that the second heat power (Pw2) supplied by the second heat exchanger (2) is equal to the set point (C_Pw2) of the second heat power to be supplied.

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

3. The control method according to claim 2, wherein, Step (ii) includes the following sub-steps: (ii3) Control the rotational speed (N) of the compressor (7) so that the pressure (P1) of the coolant fluid in the first heat exchanger (1) is equal to the determined pressure setpoint (C_P1).

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

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

6. The method according to any one of claims 1 to 3, wherein, The heat transfer fluid (F1) is the airflow (Fi) within the passenger compartment of the motor vehicle.

7. The method according to any one of claims 1 to 3, wherein, The heat transfer fluid (F1) is a heat transfer fluid configured to flow in a fifth heat exchanger (5), which is configured to exchange heat with the airflow (Fi) in the passenger space of the vehicle.

8. The method according to any one of claims 1 to 3, wherein, The second heat exchanger (2) is thermally connected to the components (25) of the vehicle's traction chain through the heat transfer fluid of the heat transfer fluid circuit (20).

9. The method according to any one of claims 1 to 3, wherein, The third heat exchanger (3) is thermally connected to the components (25) of the vehicle's traction chain via the heat transfer liquid in the heat transfer liquid circuit (20).

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

11. The thermal control system (100) according to claim 10, wherein, The coolant fluid circuit (10) includes a first branch (B) positioned in parallel with the second expansion valve (32) and the third heat exchanger (3), the first branch (B) including the third expansion valve (33) and the fourth heat exchanger (4), wherein the fourth heat exchanger (4) is configured to exchange heat with the airflow (Fi) in the passenger space of the vehicle.

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

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