Thermal control system for motor vehicles

Abstract

The present invention relates to a thermal regulation system (100) for a motor vehicle, the thermal regulation system comprising a refrigerant circuit (50) comprising a main loop (A) comprising, in sequence: - a compression device (1); - a first heat exchanger (2); - a first expansion device (3); - a second heat exchanger (4); - a third heat exchanger (6); and - a refrigerant storage device (7), wherein the volume of the portion of the main loop (A) extending from the outlet (2b) of the first heat exchanger (2) to the inlet (3a) of the first expansion device (3) defines a first reference volume, wherein the volume of the storage device (7) defines a second reference volume, and wherein the ratio of the first reference volume to the second reference volume is greater than 0.2, preferably greater than 0.4.

Description

Technical Field

[0001] This invention relates to the field of thermal regulation systems for motor vehicles. In the case of vehicles with electric propulsion, this type of system makes it possible to ensure thermal regulation of different units or parts of the vehicle (such as passenger space or energy storage batteries). Heat exchange is primarily achieved through the compression and expansion of the refrigerant within multiple heat exchangers. Background Technology

[0002] The presence of multiple bypass branches in the refrigerant circuit allows for a variety of different operating modes. In fact, by selectively opening different shut-off valves to adjust the refrigerant circuit configuration, the heat exchanger through which the refrigerant passes can be chosen. Therefore, it is possible to selectively achieve, in particular, cooling, heating, or dehumidification of the passenger compartment air.

[0003] The amount of refrigerant circulating in the refrigerant circuit is not constant, depending on the selected operating mode and the environmental conditions under which the vehicle is driven. In fact, the minimum and maximum pressures in the circuit depend on the operating conditions, and therefore the density of the refrigerant circulating in the circuit also depends on these conditions. Furthermore, the length of the portion of the circuit through which the refrigerant travels is not always the same. A refrigerant accumulator located upstream of the compressor in the circuit thus allows for a refrigerant reserve to be obtained within the circuit. The accumulator includes a refrigerant inlet, a refrigerant outlet, and a buffer volume between the inlet and outlet, which allows for the storage of a certain amount of refrigerant. Conventional motor vehicle accumulators can have a volume of 0.8L to 1L. This volume allows for the coverage of mass variations in the chemical refrigerant (such as R1234yf) circulating in the circuit.

[0004] In some vehicles, the space available under the hood may be very limited, making it difficult or even impossible to install a storage device with a regular volume.

[0005] Therefore, the object of the present invention is to provide a thermal regulation system that can be operated using an accumulator with a volume smaller than that of systems according to the prior art, while maintaining the same level of thermal performance. This is primarily advantageous for incorporating a thermal regulation circuit into a vehicle. Summary of the Invention

[0006] For this purpose, the present invention provides a thermal regulation system for a motor vehicle, the thermal regulation system including a refrigerant circuit configured to circulate refrigerant, the refrigerant circuit including:

[0007] - The main loop, which includes the following components sequentially in the direction of refrigerant travel:

[0008] --Compression device;

[0009] --A first heat exchanger, configured to exchange heat with a first heat exchange fluid;

[0010] --First expansion device;

[0011] --A second heat exchanger, which is configured to exchange heat with the airflow outside the passenger space of the vehicle;

[0012] --Second expansion device;

[0013] --A third heat exchanger, which is configured to exchange heat with the airflow inside the passenger compartment of the vehicle;

[0014] --Refrigerant storage device;

[0015] - A first bypass branch B connects a first connection point to a second connection point located on the main loop between the second heat exchanger and the second expansion device. The second connection point is located on the main loop between the third heat exchanger and the accumulator. The first bypass branch includes a first shut-off valve.

[0016] The internal volume of the portion of the main loop extending from the outlet of the first heat exchanger to the inlet of the first expansion device defines a first reference volume, wherein,

[0017] The internal volume of the storage device defines a second reference volume, and wherein,

[0018] The ratio of the first reference volume to the second reference volume is greater than 0.2, preferably greater than 0.4.

[0019] The second reference volume is selected to be smaller than that of the solution according to the prior art. In other words, the refrigerant accumulator is smaller and therefore easier to install in a vehicle. To compensate for this, the volume of the portion of the main loop extending from the outlet of the first heat exchanger to the inlet of the first expansion device is increased compared to the solution according to the prior art. This additional volume allows for the formation of a refrigerant storage volume that compensates for the reduced volume of the accumulator. In fact, in operating modes with a smaller refrigerant mass in the circulation, this portion of the loop contains refrigerant in liquid form, thus forming a natural refrigerant accumulation area. The first and second reference volumes are selected such that a refrigerant reserve is maintained in the accumulator under all operating conditions of the thermal regulation circuit.

[0020] The features listed in the following paragraphs can be implemented independently of each other, or according to all technically possible combinations.

[0021] The second reference volume is less than 0.65L.

[0022] The thermal control system includes a second bypass branch that connects a third connection point to a fourth connection point. The third connection point is located on the main loop and between the first heat exchanger and the first expansion device. The fourth connection point is located on the main loop and between the first connection point and the second expansion device. The second bypass branch includes a second shut-off valve. The sum of the volume of a first reference volume and the volume of the portion of the second bypass branch extending from the third connection point to the inlet of the shut-off valve defines a third reference volume.

[0023] Furthermore, the ratio of the third reference volume to the second reference volume is greater than 0.3, preferably greater than 0.5.

[0024] According to one embodiment, the first heat exchanger includes a first heat exchange section and a second heat exchange section, the first heat exchange section being configured to ensure refrigerant condensation and the second heat exchange section being configured to ensure refrigerant subcooling.

[0025] The sum of the third reference volume and the internal volume of the second heat exchange section of the first heat exchanger defines the fourth reference volume.

[0026] Furthermore, the ratio of the fourth reference volume to the second reference volume is greater than 0.65, preferably greater than 0.95.

[0027] According to one embodiment of the thermal control system, a first heat exchanger is configured to exchange heat with the airflow inside the passenger compartment of the vehicle.

[0028] According to another embodiment of the thermal control system, the first heat exchanger is configured to exchange heat with the heat exchange liquid circulating in the heat exchange liquid loop.

[0029] The heat exchange liquid circuit includes a fifth heat exchanger configured to exchange heat with the airflow inside the passenger compartment of the vehicle.

[0030] According to one embodiment, the thermal control system includes a third bypass branch that connects a fifth connection point to a sixth connection point, the fifth connection point being located on the main loop and between a fourth connection point and a second expansion device, the sixth connection point being located on the main loop and between a second connection point and an accumulation device, and the third bypass branch including a third expansion device located upstream of a fourth heat exchanger.

[0031] The fourth heat exchanger 20 is thermally connected to the element 30 of the vehicle's electric traction chain. The element 30 of the electric traction chain may be an energy storage battery 30. The element 30 of the electric traction chain may be an electronic module for controlling the vehicle's traction motor.

[0032] According to one embodiment of the thermal control system, the sum of the volume of the portion of the main loop extending from the outlet of the second heat exchanger to the first connection point and the volume of the portion of the first bypass branch extending from the first connection point to the inlet of the first shut-off valve defines a fifth reference volume, and the fifth reference volume is less than 0.03L.

[0033] According to one embodiment, the ratio of the fifth reference volume to the second reference volume is less than 0.5, preferably less than 0.1.

[0034] According to one embodiment of the thermal control system, the inner diameter of the portion of the main loop between the outlet of the first heat exchanger and the inlet of the first expansion device is greater than 13 mm, preferably greater than 15 mm.

[0035] According to one embodiment, the main loop includes a check valve positioned between a first connection point and a fourth connection point, the length of the portion of the main loop extending from the first connection point to the check valve defines a first reference distance, and the length of the portion of the main loop extending from the check valve to the fourth connection point defines a second reference distance, and the ratio of the first reference distance to the second reference distance is less than 0.5.

[0036] Preferably, the volume of the portion of the main loop extending from the first connection point to the check valve is less than 0.03L.

[0037] According to one embodiment of the thermal control system, the portion of the main loop extending from the outlet of the first heat exchanger to the inlet of the first expansion device includes a first portion having a first passage cross-section of refrigerant and a second portion having a second passage cross-section of refrigerant, wherein the ratio between the second passage cross-section and the first passage cross-section is greater than 2.

[0038] The present invention also relates to the process of the thermal conditioning system as described above operating in heating mode, in which:

[0039] - The refrigerant circulates in the compressor unit where it becomes high pressure, and then circulates in the first heat exchanger where it generates heat to the heat exchange fluid and becomes liquid. It then circulates to the first expansion unit where it becomes low pressure, and then circulates to the second heat exchanger where it absorbs heat from the outside air flow and becomes gaseous. It then circulates to the first bypass branch and then to the storage unit.

[0040] -Then the low-pressure refrigerant returns to the compressor unit.

[0041] The present invention also relates to the process of operating the thermal control system as described above in a so-called cooling mode, in which:

[0042] - The refrigerant circulates in the compressor unit where it becomes high pressure, and then circulates in the first heat exchanger without generating heat to the internal airflow, circulates to the first expansion unit, circulates to the second heat exchanger where it generates heat to the external airflow and becomes liquid.

[0043] - It circulates to the second expansion device, where it becomes low pressure, then circulates to the third heat exchanger, where it becomes gaseous and absorbs heat from the internal airflow, and then circulates to the storage device.

[0044] -Then the low-pressure refrigerant returns to the compressor unit.

[0045] The present invention also relates to the process of operating the thermal control system as described above in a so-called cooling mode, in which:

[0046] - The refrigerant circulates in the compressor unit where it becomes high pressure, and then circulates in the first heat exchanger where it generates heat to the heat transfer fluid and becomes liquid, then circulates to the first expansion unit, and then to the second heat exchanger.

[0047] - It circulates to the second expansion device, where it becomes low pressure, then circulates to the third heat exchanger, where it becomes gaseous and absorbs heat from the internal airflow, and then circulates to the storage device.

[0048] -Then the low-pressure refrigerant returns to the compressor unit.

[0049] The present invention also relates to the process of operating the thermal conditioning system as described above in a so-called parallel dehumidification mode, wherein:

[0050] - The refrigerant circulates in the compressor and becomes high pressure there, and then circulates in the first heat exchanger and generates heat to the heat exchange fluid there and becomes liquid.

[0051] - The refrigerant is divided into a first flow circulating in the main loop and a second flow circulating in the second bypass branch;

[0052] - The first stream circulates in the first expansion device and becomes low pressure there, then circulates to the second heat exchanger where it absorbs heat from the outside airflow and becomes gaseous, and then circulates in the first bypass branch.

[0053] - The second flow merges into the main loop A upstream of the second expansion device and becomes low pressure at the second expansion device. It then circulates in the third heat exchanger and absorbs heat from the internal air flow at the third heat exchanger and becomes gaseous.

[0054] -The first and second streams converge at the second junction and then circulate in the accumulator.

[0055] -Then the low-pressure refrigerant returns to the compressor unit. Attached Figure Description

[0056] Other features, details, and advantages will become apparent by reading the following detailed description and studying the accompanying drawings, which are shown in the drawings:

[0057] Figure 1 This is a schematic representation of a thermal regulation system according to a first embodiment of the present invention.

[0058] Figure 2 This is a schematic representation of a thermal regulation system according to a second embodiment of the present invention.

[0059] Figure 3 It is based on Figure 2 A schematic representation of the thermal regulation system of the first variant embodiment.

[0060] Figure 4 It is based on Figure 2 A schematic representation of the thermal regulation system in a second variant embodiment.

[0061] Figure 5 This is a partial schematic representation of a variant of the thermal regulation system according to the present invention.

[0062] Figure 6 express Figure 1 The thermal regulation system operates according to a pressure-enthalpy diagram based on a so-called cooling operation mode.

[0063] Figure 7 express Figure 1 The thermal control system operates according to a pressure-enthalpy diagram based on a so-called heating operation mode.

[0064] 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 as, 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 any priority of one element or parameter over another, and these names are interchangeable. Detailed Implementation

[0065] In the following description, the term "first element upstream of the second element" means that, relative to the direction of fluid circulation or travel, the first element is positioned before the second element. Similarly, the term "first element downstream of the second element" means that, relative to the direction of fluid circulation or travel, the first element is positioned after the second element. In the case of a refrigerant circuit, the term "first element upstream of the second element" means that the refrigerant travels successively through the first and second elements without passing through the compressor. In other words, the refrigerant leaves the compressor, optionally passes through multiple elements, then through the first element, then through the second element, and then returns to the compressor, optionally having passed through other elements before returning.

[0066] When a specified subsystem includes a given element, this does not preclude the presence of other elements in this subsystem.

[0067] "Internal Airflow Fi" refers to the airflow designed for use in the passenger space of a motor vehicle. This internal airflow can circulate within a heating, ventilation, and air conditioning (HVAC) system. This system is not shown in the diagram.

[0068] "External airflow Fe" refers to airflow not intended for passenger space. In other words, this airflow remains outside the vehicle. If necessary, a motorized fan unit (not shown) can be activated to increase the flow rate of external airflow Fe. Similarly, if necessary, another motorized fan unit (not shown) can be positioned within the heating system to increase the flow rate of internal airflow Fi.

[0069] The electronic control unit (not shown in the figure) receives information from multiple different sensors that measure, in particular, the characteristics of the refrigerant at multiple different points in the circuit. The electronic unit also receives commands input by the vehicle's occupants, such as desired temperatures within the passenger compartment. The electronic unit implements control laws that allow control of multiple different actuators to control the thermal regulation system 100.

[0070] Each of the first, second, and third expansion devices can be an electronic expansion device, a thermostatic expansion device, or a calibration orifice. In the case of an electronic expansion device, the cross-sectional area of ​​the passage through which the refrigerant can pass can be continuously adjusted between a closed position and a maximum open position. For this purpose, the system's control unit controls a motor that moves a movable gate, which controls the cross-sectional area of ​​the expansion device's passage.

[0071] The compressor unit 1 can be an electric compressor, i.e., a compressor with moving parts driven by an electric motor. The compressor unit includes a side for drawing in refrigerant at low pressure (also referred to as the inlet of the compressor unit) and a side for delivering refrigerant at high pressure (also referred to as the outlet of the compressor unit 1). The internal moving parts of the compressor move the refrigerant from the low pressure at the inlet side to the high pressure at the outlet side. After expanding in one or more expansion units in circuit 1, the refrigerant returns to the inlet of compressor 1 and begins a new thermodynamic cycle.

[0072] Each connection point allows refrigerant to pass through one or more loop sections joined at that connection point. By adjusting the opening or closing of the shut-off valves or expansion devices included on each of the two branches, the refrigerant is distributed between the two loop sections joined at the connection point. In other words, each connection point is a device for redirecting the fluid arriving at that connection point.

[0073] Therefore, shut-off valves and check valves allow refrigerant to be selectively directed into multiple different branches of the refrigerant circuit to provide different operating modes, as will be described below.

[0074] Therefore, the first shut-off valve 8 is configured to selectively allow or prevent refrigerant from passing through into the first bypass branch B. In the same manner, the second shut-off valve 9 is configured to selectively allow or prevent refrigerant from passing through into the second bypass branch C.

[0075] Refrigerant circuit 1 includes a device 7 for storing refrigerant, which is located on the main loop A, upstream of the compressor unit 1. The refrigerant used in refrigerant circuit 1 is, in this case, a chemical fluid, such as R1234yf. Other refrigerants, such as R134a, may also be used.

[0076] Figure 1 A first embodiment of the present invention is shown. Therefore, Figure 1 A thermal regulation system 100 for a motor vehicle is shown, the thermal regulation system including a refrigerant circuit 50 configured to circulate refrigerant, the refrigerant circuit 50 including:

[0077] - Main loop A, which includes the following components in the direction of refrigerant travel:

[0078] --Compression device 1;

[0079] --First heat exchanger 2, which is configured to exchange heat with first heat exchange fluid Fc;

[0080] --First expansion device 3;

[0081] --Second heat exchanger 4, which is configured to exchange heat with the external airflow Fe heading towards the passenger space of the vehicle;

[0082] --Second expansion device 5;

[0083] --Third heat exchanger 6, which is configured to exchange heat with the airflow Fi inside the passenger compartment of the vehicle;

[0084] --A device 7 for storing refrigerant;

[0085] - A first bypass branch B, which connects a first connection point 11 to a second connection point 12, the first connection point being located on the main loop A and between the second heat exchanger 4 and the second expansion device 5, the second connection point being located on the main loop A and between the third heat exchanger 6 and the storage device 7, the first bypass branch B including a first shut-off valve 8, wherein...

[0086] The volume of the portion of the main loop A extending from the outlet 2b of the first heat exchanger 2 to the inlet 3a of the first expansion device 3 defines a first reference volume V1, and wherein,

[0087] The internal volume of the storage device 7 defines a second reference volume V2, and wherein,

[0088] The ratio R1 of the first reference volume V1 to the second reference volume V2 is greater than 0.2, preferably greater than 0.4.

[0089] The second reference volume V2 is less than 0.65L.

[0090] To calculate the ratio R1, the value of the first reference volume V1 is divided by the value of the second reference volume V2, where each volume V1 and V2 is expressed in the same unit of measurement (e.g., liter). Therefore, the ratio R1 is a dimensionless value. For example, if the first reference volume V1 is 0.3 L and the second reference volume V2 is 0.5 L, then the value of the ratio R1 is 0.6.

[0091] The first reference volume V1 is determined by calculating the volume of the portion of the refrigerant circuit that begins at the outlet 2b of the first heat exchanger 2 and ends at the inlet 3a of the first expansion device 3. Therefore, this first reference volume is the volume set for the refrigerant between the outlet 2b and the inlet 3a.

[0092] The second reference volume V2, which is equal to the internal volume of the storage device 7, is the volume between the inlet 7a and the outlet 7b of the storage device 7. Therefore, the mass of the refrigerant stored in the storage device 7 is equal to the reference volume V2 multiplied by the average density of the refrigerant contained in the storage device.

[0093] The thermal control system 100 is configured to operate according to a variety of different operating modes. Specifically, the thermal control system 100 can implement a process of operation in heating mode, in which:

[0094] - The refrigerant circulates in the compressor 1 and becomes high pressure there, and then circulates in the first heat exchanger 2 where it generates heat to the heat exchange fluid and becomes liquid. It then circulates to the first expansion unit 3 where it becomes low pressure. It then circulates to the second heat exchanger 4 where it absorbs heat from the external airflow Fe and becomes gaseous. It then circulates to the first bypass branch B and then to the storage unit 7.

[0095] -Then the low-pressure refrigerant returns to the compressor unit 2.

[0096] The fact that the refrigerant becomes high-pressure through circulation in the compressor means that the refrigerant leaves the compressor at a so-called high-pressure state. The pressure at the outlet of the compressor is greater than the pressure at the inlet. "Entering the liquid state" means that at least part of the refrigerant condenses and becomes liquid. This transformation is not necessarily complete, and the refrigerant may be in the form of a mixture of liquid and vapor. In the same way, "entering the gaseous state" means that at least part of the refrigerant vaporizes and becomes gaseous. Again, in this case, the transformation is not necessarily complete, and the refrigerant may be in the form of a mixture of liquid and vapor.

[0097] In other words, in the heating mode of operation, the portion of the main loop A extending from the outlet 2b of the first heat exchanger 2 to the inlet 3a of the first expansion device 3 contains refrigerant in a liquid state.

[0098] On the other hand, when the thermal control system operates in a mode that cools the passenger space, this part of the circuit contains refrigerant in a gaseous state.

[0099] In fact, when the thermal control system 100 operates in the so-called cooling mode:

[0100] - The refrigerant circulates in the compressor 1 and becomes high pressure there, and then circulates in the first heat exchanger 2 without changing its state, circulates to the first expansion unit 3, and circulates to the second heat exchanger 4 where it flows to the outside air, generates heat, and becomes liquid.

[0101] - It circulates to the second expansion device 5, where it becomes low pressure, then circulates to the third heat exchanger 6, where it becomes gaseous and absorbs heat from the internal airflow Fi, and then circulates to the storage device 7.

[0102] -Then the low-pressure refrigerant returns to the compressor unit 2.

[0103] Figure 6 This is a pressure-enthalpy diagram of the refrigerant during the thermodynamic cycle described when the thermal control system 100 operates in cooling mode. The dashed curve corresponds to the characteristic curve of the refrigerant's state change. The solid trapezoidal line corresponds to the thermodynamic cycle generated by the refrigerant.

[0104] Point p1 illustrates the state of the refrigerant at the inlet of the compressor 1. Points p2 and p3 illustrate the states of the refrigerant at the outlets of the first heat exchanger 2 and the first expansion unit 3, respectively. Point 4b illustrates the state of the refrigerant at the outlet of the second heat exchanger 4, and reference numeral Q4 illustrates the heat exchange between the high-pressure refrigerant within the second heat exchanger 4 and the external airflow Fe. Point p5 indicates the state of the fluid at the outlet of the second expansion unit 5. Points p6, p12, and p7b represent the states of the refrigerant at the outlet of the third heat exchanger 6, the refrigerant at the second connection point 12, and the refrigerant at the outlet 7b of the accumulator 7, respectively. Because load losses and heat losses (e.g., load losses and heat losses between the second connection point 12 and the accumulator 7) are considered negligible, these points are combined in this figure. Reference numeral Q6 illustrates the heat exchange between the low-pressure refrigerant within the third heat exchanger 6 and the internal airflow Fi. This heat exchange ensures the cooling of the internal airflow Fi.

[0105] Figure 7 It is a pressure-enthalpy diagram of the refrigerant during the thermodynamic cycle described when the thermal control system 100 is operating in heating mode.

[0106] Point p1 indicates the state of the refrigerant at the inlet of the compressor 1. Point p2 indicates the state of the refrigerant at the inlet of the first heat exchanger 2. Points p2b and p3a indicate the states of the refrigerant at the outlet of the first heat exchanger 2 and the inlet of the first expansion device 3 (i.e., before expansion), respectively. Reference numerals Q21 and Q22 indicate the heat exchange that occurs between the high-pressure refrigerant and the internal airflow Fi within the first heat exchanger 2. This heat exchange ensures the heating of the internal airflow Fi. Reference numeral Q21 corresponds to the heat exchange during the condensation phase of the refrigerant, and reference numeral Q22 corresponds to the heat exchange during the subcooling phase of the refrigerant. Point p4 indicates the state of the fluid at the inlet of the second heat exchanger 4. Points p4b, p8, p12, and p7 indicate the states of the refrigerant at the outlet of the second heat exchanger 4, the state of the refrigerant at the first shut-off valve 8, the state of the refrigerant at the second connection point 12, and the state of the refrigerant at the outlet 7b of the accumulator 7, respectively. Because load losses and heat losses (e.g., load losses and heat losses between the first shut-off valve 8 and the accumulator 7) are considered negligible, these points are combined in the figure. Reference numeral Q4 illustrates the heat exchange that occurs between the low-pressure refrigerant within the second heat exchanger 4 and the external airflow Fe.

[0107] In the cooling mode of operation, refrigerant condensation occurs in the second heat exchanger 4. Therefore, the portion of the main loop A upstream of this exchanger 4 contains gaseous refrigerant, and thus has a lower density than liquid refrigerant. Because the minimum and maximum pressures of the thermodynamic cycle are higher in cooling mode than in heating mode, the mass of refrigerant circulating in loop 50 is generally greater in cooling mode than in heating mode. Therefore, the average density of the refrigerant is higher in cooling mode, resulting in a greater mass of refrigerant circulating in loop 50. Consequently, the accumulator 7 must store more refrigerant when the system operates in a mode that heats the passenger space than it would store when the system operates in a mode that cools the passenger space.

[0108] The portion of the main loop A extending from the outlet 2b of the first heat exchanger 2 to the inlet 3a of the first expansion device 3 is filled with liquid in heating mode to store refrigerant that does not circulate in the loop (i.e., refrigerant that does not participate in the thermodynamic cycle). Because this portion of the main loop can function similarly to the accumulator 7, by appropriately selecting the size of this portion of the main loop, an accumulator 7 with a volume smaller than that in solutions according to the prior art can be used. The size is appropriate when the ratio R1 of the first reference volume V1 to the second reference volume V2 is greater than 0.2, preferably greater than 0.4.

[0109] The second heat exchanger 4 can be positioned at the front of the vehicle and receives the airflow generated by the vehicle moving forward. The first heat exchanger 2 and the third heat exchanger 6 can be positioned within the vehicle's heating, ventilation, and air conditioning system.

[0110] The first connection point 11 is located on the main loop A, downstream of the second heat exchanger 4 and upstream of the second expansion device 5. The second connection point 12 is located on the main loop A, downstream of the third heat exchanger 6 and upstream of the accumulator 7. The first connection point 11 belongs to both the main loop A and the first bypass branch B. Similarly, the second connection point 12 belongs to both the main loop A and the first bypass branch B. The first shut-off valve 8 is located on the first bypass branch B, downstream of the first connection point 11 and upstream of the second connection point 12.

[0111] Figure 2 A second embodiment of the invention is shown. In this second embodiment, the thermal control system 100 includes a second bypass branch C that connects a third connection point 13 to a fourth connection point 14. The third connection point is located on the main loop A and between the first heat exchanger 2 and the first expansion device 3. The fourth connection point is located on the main loop A and between the first connection point 11 and the second expansion device 5. The second bypass branch C includes a second shut-off valve 9.

[0112] The sum of the contents of the first reference volume V1 and the portion of the second bypass branch C extending from the third connection point 13 to the inlet 9a of the shut-off valve 9 defines the third reference volume V3.

[0113] Furthermore, the ratio of the third reference volume V3 to the second reference volume V2 is greater than 0.3, preferably greater than 0.5.

[0114] Therefore, the third reference volume V3 is the sum of the calculated second reference volume V2 and the volume of the portion of the circuit that begins at the third connection point 13 and ends at the inlet 9a of the shut-off valve 9.

[0115] The second shut-off valve 9 is configured to selectively allow or prevent refrigerant from passing through into the second bypass branch C. The main loop A includes a check valve 23 located between the first connection point 11 and the fourth connection point 14. The third connection point 13 is located on the main loop A, downstream of the first heat exchanger 2 and upstream of the first expansion device 3. The fourth connection point 14 is located on the main loop A, downstream of the first connection point 11 and upstream of the second expansion device 5. The check valve 23 is located downstream of the first connection point 11 and upstream of the fourth connection point 14.

[0116] In this embodiment, the portion of the circuit comprising the refrigerant in a liquid state in heating mode and the refrigerant in a gaseous state in cooling mode includes... Figure 1The same part as the embodiment, except that a second bypass branch C is added to that same part, which starts at the third connection point 13 and ends at the inlet 9a of the shut-off valve 9.

[0117] As mentioned earlier, this part of the circuit allows for the storage of refrigerant in a liquid state, which enables the use of a smaller accumulator 7 while ensuring the same level of thermodynamic performance.

[0118] Figure 3 yes Figure 2 A variation of the embodiment. In this variation, the first heat exchanger 2 is configured to exchange heat with the airflow Fi inside the passenger compartment of the vehicle. The first heat exchange fluid Fc is, in this case, the internal airflow Fi. For the sake of simplicity in the drawings, the third heat exchanger 6 and the first heat exchanger 2, both configured to exchange heat with the same internal airflow Fi, are not shown in parallel. In fact, exchangers 6 and 2 are mounted upstream of each other.

[0119] In this configuration, the first heat exchange fluid Fc is the airflow Fi inside the passenger compartment of the vehicle. The first heat exchanger 2 ensures heating of the internal airflow Fi, thus heating the passenger compartment of the vehicle. The first heat exchanger 2 is referred to as an internal condenser in this configuration.

[0120] according to Figure 3 In the illustrated embodiment, the first heat exchanger 2 includes a first heat exchange section 21 and a second heat exchange section 22. The first heat exchange section is configured to ensure refrigerant condensation, and the second heat exchange section is configured to ensure refrigerant subcooling.

[0121] The sum of the third reference volume V3 and the internal volume of the second heat exchange section 22 of the first heat exchanger 2 defines the fourth reference volume V4.

[0122] Furthermore, the ratio of the fourth reference volume V4 to the second reference volume V2 is greater than 0.65, preferably greater than 0.95.

[0123] In other words, the heat exchange region of the first heat exchanger 2 that ensures the subcooling of the refrigerant also contributes to the formation of the refrigerant storage region. This contributing effect is added to the region already defined in the preceding paragraph. Therefore, the fourth reference volume V4 is the sum of the calculated third reference volume V3 and the volume of the subcooling portion of the heat exchanger 2.

[0124] Figure 4 yes Figure 2 Another variation of the embodiment. According to this variation, the first heat exchanger 2 is configured to exchange heat with the heat exchange liquid circulating in the heat exchange liquid loop 40.

[0125] In other words, the first heat exchange fluid Fc is a heat exchange liquid in this case. For example, a mixture of water and ethylene glycol can be used. The first heat exchanger 2 is a two-fluid exchanger in this case, which is configured to allow heat exchange between the refrigerant circulating in loop 50 and the heat exchange fluid circulating in loop 40.

[0126] The heat exchange liquid circuit 40 includes a fifth heat exchanger 25 configured to exchange heat with the airflow Fi inside the passenger compartment of the vehicle. The passenger compartment is heated by the fifth heat exchanger 25. For this purpose, the heat exchange liquid circuit 40 recovers heat generated due to the condensation of high-pressure, high-temperature refrigerant from the compressor 1 in the two-fluid exchanger 2.

[0127] The heat exchange fluid circuit 40 includes a pump 27 configured to circulate the heat exchange fluid within the circuit 40. The heat exchange fluid circuit 40 also includes a heating device 26 configured to heat the heat exchange fluid. The heating device 26 is an electric heater. Therefore, the heating device 26 enables the operation of the dual-fluid exchanger 2 to heat the heat exchange fluid. The heat exchange fluid circuit 40 also includes a sixth heat exchanger 28 configured to exchange heat with the external airflow Fe flowing into the passenger compartment of the vehicle. Therefore, the sixth heat exchanger 28 enables the cooling of the heat exchange fluid in operating modes requiring this type of cooling.

[0128] according to Figure 2 , Figure 3 and Figure 4 In the illustrated embodiment, the thermal control system 100 includes a third bypass branch D that connects a fifth connection point 15 to a sixth connection point 16. The fifth connection point is located on the main loop and between the fourth connection point 14 and the second expansion device 5. The sixth connection point is located on the main loop A and between the second connection point 12 and the accumulator device 7. The third bypass branch D includes a third expansion device 10, which is located upstream of the fourth heat exchanger 20. The fifth connection point 15 is located on the main loop A, downstream of the fourth connection point 14, and upstream of the second expansion device 5. The sixth connection point 16 is located on the main loop A, downstream of the second connection point 12, and upstream of the accumulator device 7. According to variations not shown, the fifth connection point 15 may be combined with the fourth connection point 14. Similarly, the sixth connection point 16 may be combined with the second connection point 12.

[0129] According to an undisclosed variant, the third bypass branch D connects the fifth connection point 15 to the sixth connection point 16, which is located on the main loop and between the fourth connection point 14 and the second expansion device 5. The sixth connection point is located on the first bypass branch B and between the first shut-off valve 8 and the second connection point 12. The third bypass branch D includes a third expansion device 10, which is located upstream of the fourth heat exchanger 20. From a thermodynamic point of view, this variant is equivalent to... Figure 2 , Figure 3 and Figure 4 A variant of .

[0130] A fourth heat exchanger 20 is configured to be thermally connected to an element 30 of the vehicle's electric traction chain. In other words, the third heat exchanger 20 is configured to exchange heat with the element 30 of the vehicle's traction chain. This heat exchange can be direct, i.e., the exchanger 20 is in contact with the element 30. This heat exchange can also be indirect, i.e., heat exchange between the element 30 and the fourth heat exchanger 20 occurs through a heat exchange fluid circulating in a closed loop. The element 30 of the electric traction chain can be an electrical energy storage battery 30. The battery 30 can supply electrical energy to the vehicle's traction motor. The element 30 of the electric traction chain can be an electronic module for controlling the vehicle's traction motor.

[0131] According to the thermal control system, the sum of the volume of the portion of the main loop extending from the outlet 4b of the second heat exchanger 4 to the first connection point 11 and the volume of the portion of the first bypass branch B extending from the first connection point 11 to the inlet 8a of the first shut-off valve 8 defines the fifth reference volume V5, and the fifth reference volume is less than 0.03L.

[0132] The ratio of the fifth reference volume V5 to the second reference volume V2 is less than 0.5, preferably less than 0.1.

[0133] In other words, the desired value is a lower fifth reference volume.

[0134] Such as especially Figure 2 As illustrated, the main loop A includes a check valve 23 positioned between a first connection point 11 and a fourth connection point 14. The length of the portion of the main loop A extending from the first connection point 11 to the check valve 23 defines a first reference distance d1, and the length of the portion of the main loop A extending from the check valve 23 to the fourth connection point 14 defines a second reference distance d2. The ratio of the first reference distance d1 to the second reference distance d2 is less than 0.5.

[0135] Preferably, the volume of the portion of the main loop A extending from the first connection point 11 to the check valve 23 is less than 0.03L. In other words, the volume of the portion of the main loop A corresponding to the first reference distance d1 is less than 0.03L.

[0136] According to a variant embodiment of the thermal control system 100, Figure 5 The diagram illustrates a portion of the thermal regulation system. The main loop extending from the outlet 2b of the first heat exchanger 2 to the inlet 3a of the first expansion device 3 includes a first portion having a first passage cross-section S1 for the refrigerant and a second portion having a second passage cross-section S2 for the refrigerant, the ratio of the second passage cross-section S2 to the first passage cross-section S1 being greater than 2. The "passage cross-section" at a given location in the refrigerant loop refers to the surface area of ​​a straight section of the loop at that location.

[0137] In other words, the portion of the main loop extending from the outlet 2b of the first heat exchanger 2 to the inlet 3a of the first expansion device 3 does not have a constant cross-sectional area. Additional volume is added to the refrigerant circulation pipe. This additional volume allows for the formation of an area for storing the refrigerant. This additional volume also allows for the reduction of noise caused by refrigerant circulation, particularly during periods of sudden pressure changes.

[0138] according to Figure 5 In one embodiment of the illustrated thermal regulation system, the inner diameter of the portion of the main loop between the outlet 2b of the first heat exchanger 2 and the inlet 3a of the first expansion device 3 is greater than 13 mm, preferably greater than 15 mm. In other words, the diameter of the pipe used to form this portion of the main loop is larger than the diameter of solutions according to the prior art, so as to constitute a region for storing liquid refrigerant.

[0139] The thermal control system 100 can operate in several different operating modes, depending on the flow and pressure of the refrigerant circulating in the main loop A and the different bypass branches B, C, and D.

[0140] According to one embodiment, the thermal regulation system 100 can also implement a process of operating in a so-called cooling mode, in which:

[0141] - The refrigerant circulates in the compressor 1 and becomes high pressure there, and then circulates in the first heat exchanger 2 without generating heat to the internal airflow Fi, circulates to the first expansion unit 3, circulates to the second heat exchanger 4 and generates heat to the external airflow Fe there and becomes liquid.

[0142] - It circulates to the second expansion device 5, where it becomes low pressure, then circulates to the third heat exchanger 6, where it becomes gaseous and absorbs heat from the internal airflow Fi, and then circulates to the storage device 7.

[0143] -Then the low-pressure refrigerant returns to compressor unit 2. This operation is applicable, for example, to... Figure 3 Examples of implementations.

[0144] According to another embodiment, the thermal regulation system 100 can also implement a process of operating in another so-called cooling mode, in which:

[0145] - The refrigerant circulates in the compressor 1 and becomes high pressure there, and then circulates in the first heat exchanger 2 where it generates heat to the heat exchange fluid and becomes liquid, then circulates to the first expansion unit 3, and then to the second heat exchanger 4.

[0146] - It circulates to the second expansion device 5, where it becomes low pressure, then circulates to the third heat exchanger 6, where it becomes gaseous and absorbs heat from the internal airflow Fi, and then circulates to the storage device 7.

[0147] -Then the low-pressure refrigerant returns to compressor unit 2. This operation is applicable, for example, to... Figure 4 Examples of implementations.

[0148] The thermal control system 100 can also perform a process in a so-called parallel dehumidification mode, in which:

[0149] - The refrigerant circulates in the compressor 1 and becomes high pressure therein, and then circulates in the first heat exchanger 2 and generates heat to the heat exchange fluid therein and becomes liquid.

[0150] - The refrigerant is divided into a first flow that circulates in the main loop A and a second flow that circulates in the second bypass branch C;

[0151] - The first stream circulates in the first expansion device 3 and becomes low pressure there, then circulates to the second heat exchanger 4 and absorbs heat from the external airflow Fe and becomes gaseous, then circulates successively in the first bypass branch B.

[0152] - The second flow merges into the main loop A upstream of the second expansion device 5 and becomes low pressure at the second expansion device, then circulates in the third heat exchanger 6 and absorbs heat from the internal air flow Fi at the third heat exchanger and becomes gaseous;

[0153] - The first and second streams converge at the second connection point 12 and then circulate in the accumulation device 7;

[0154] -Then the low-pressure refrigerant returns to the compressor unit 2.

[0155] In this parallel dehumidification mode, the low-pressure refrigerant circulates in the first heat exchanger 2, the second heat exchanger 4, and the third heat exchanger 6.

[0156] The thermal control system 100 can also operate in a mode that ensures cooling or heating of the components 30 of the electric traction chain.

Claims

1. A thermal regulation system (100) for a motor vehicle, the thermal regulation system comprising a refrigerant circuit (50) configured to circulate refrigerant, the refrigerant circuit (50) comprising: - Main loop (A), wherein the main loop comprises, in sequence, the following components in the direction of refrigerant travel: --Compression device (1); --First heat exchanger (2), the first heat exchanger is configured to exchange heat with a first heat exchange fluid (Fc); --First expansion device (3); --Second heat exchanger (4), the second heat exchanger is configured to exchange heat with the airflow (Fe) outside the passenger space of the vehicle; --Second expansion device (5); -- A third heat exchanger (6) is configured to exchange heat with the airflow (Fi) inside the passenger space of the vehicle; --Refrigerant storage device (7); - A first bypass branch (B) connects a first connection point (11) to a second connection point (12), the first connection point being located on the main loop (A) and between the second heat exchanger (4) and the second expansion device (5), the second connection point being located on the main loop (A) and between the third heat exchanger (6) and the accumulator device (7), the first bypass branch (B) including a first shut-off valve (8), wherein, The volume of the portion of the main loop (A) extending from the outlet (2b) of the first heat exchanger (2) to the inlet (3a) of the first expansion device (3) defines a first reference volume V1, wherein, The internal volume of the storage device (7) defines a second reference volume V2, and wherein, The ratio R1 of the first reference volume V1 to the second reference volume V2 is greater than 0.

2.

2. The thermal control system (100) as described in claim 1, wherein, The ratio R1 of the first reference volume V1 to the second reference volume V2 is greater than 0.

4.

3. The thermal control system (100) as described in claim 1, wherein, The second reference volume V2 is less than 0.65L.

4. The thermal control system (100) as claimed in claim 1, 2, or 3, the thermal control system comprising a second bypass branch (C) connecting a third connection point (13) to a fourth connection point (14), the third connection point being located on the main loop (A) and between the first heat exchanger (2) and the first expansion device (3), the fourth connection point being located on the main loop (A) and between the first connection point (11) and the second expansion device (5), the second bypass branch (C) comprising a second shut-off valve (9), wherein, The sum of the contents of the first reference volume V1 and the portion of the second bypass branch (C) extending from the third connection point (13) to the inlet (9a) of the second shut-off valve (9) defines the third reference volume V3, wherein the ratio of the third reference volume V3 to the second reference volume V2 is greater than 0.

3.

5. The thermal control system (100) as described in claim 4, wherein, The ratio of the third reference volume V3 to the second reference volume V2 is greater than 0.

5.

6. The thermal control system (100) as claimed in claim 4, wherein, The first heat exchanger (2) includes a first heat exchange section (21) and a second heat exchange section (22), wherein the first heat exchange section is configured to ensure the condensation of the refrigerant, and the second heat exchange section is configured to ensure the subcooling of the refrigerant, wherein... The sum of the third reference volume V3 and the internal volume of the second heat exchange section (22) of the first heat exchanger (2) defines the fourth reference volume V4, and wherein, The ratio of the fourth reference volume V4 to the second reference volume V2 is greater than 0.

65.

7. The thermal control system (100) as claimed in claim 6, wherein, The ratio of the fourth reference volume V4 to the second reference volume V2 is greater than 0.

95.

8. The thermal control system (100) as claimed in claim 1, wherein, The first heat exchanger (2) is configured to exchange heat with the airflow (Fi) inside the passenger space of the vehicle.

9. The thermal control system (100) as claimed in claim 1, wherein, The first heat exchanger (2) is configured to exchange heat with a heat exchange liquid circulating in a heat exchange liquid circuit (40), and wherein the heat exchange liquid circuit (40) includes a fifth heat exchanger (25) configured to exchange heat with the airflow (Fi) inside the passenger space of the vehicle.

10. The thermal regulation system (100) of claim 4, the thermal regulation system comprising a third bypass branch (D) connecting a fifth connection point (15) to a sixth connection point (16), the fifth connection point being located on the main loop and between the fourth connection point (14) and the second expansion device (5), the sixth connection point being located on the main loop (A) and between the second connection point (12) and the storage device (7), the third bypass branch (D) comprising a third expansion device (10) being located upstream of the fourth heat exchanger (20).

11. The thermal control system (100) as claimed in claim 1, wherein, The sum of the volume of the portion of the main loop extending from the outlet (4b) of the second heat exchanger (4) to the first connection point (11) and the volume of the portion of the first bypass branch (B) extending from the first connection point (11) to the inlet (8a) of the first shut-off valve (8) defines a fifth reference volume V5, wherein the fifth reference volume is less than 0.03L.

12. The thermal control system (100) as claimed in the preceding claim, wherein, The ratio of the fifth reference volume V5 to the second reference volume V2 is less than 0.

5.

13. The thermal control system (100) as claimed in claim 12, wherein, The ratio of the fifth reference volume V5 to the second reference volume V2 is less than 0.

1.

14. The thermal control system (100) as claimed in claim 1, wherein, The inner diameter of the portion of the main loop between the outlet (2b) of the first heat exchanger (2) and the inlet (3a) of the first expansion device (3) is greater than 13 mm.

15. The thermal control system (100) as claimed in claim 1, wherein, The inner diameter of the portion of the main loop between the outlet (2b) of the first heat exchanger (2) and the inlet (3a) of the first expansion device (3) is greater than 15 mm.

16. The thermal control system (100) as claimed in claim 4, wherein, The main loop (A) includes a check valve (23) positioned between the first connection point (11) and the fourth connection point (14), wherein the length of the portion of the main loop (A) extending from the first connection point (11) to the check valve (23) defines a first reference distance (D1), and wherein the length of the portion of the main loop (A) extending from the check valve (23) to the fourth connection point (14) defines a second reference distance (D2), and wherein the ratio of the first reference distance (D1) to the second reference distance (D2) is less than 0.5, and wherein the volume of the portion of the main loop (A) extending from the first connection point (11) to the check valve (23) is less than 0.03L.

17. The thermal control system (100) as claimed in claim 1, wherein, The portion of the main loop extending from the outlet (2b) of the first heat exchanger (2) to the inlet (3a) of the first expansion device (3) includes a first portion having a first passage cross section (S1) of refrigerant and a second portion having a second passage cross section (S2) of refrigerant, wherein the ratio between the second passage cross section (S2) and the first passage cross section (S1) is greater than 2.

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