Thermal conditioning system

Abstract

The invention relates to a thermal conditioning system (100) for a motor vehicle, which thermal conditioning system has: - a main loop (A) for circulating coolant, which main loop successively comprises: - a compressor (1); - a first heat exchanger (21); - a device (2) for storing the coolant; - a second heat exchanger (22); - a first bypass branch (B) connecting a first connection point (11) to a second connection point (12); - a second bypass branch (C) connecting a third connection point (13) to a fourth connection point (14); - a third bypass branch (D) connecting a fifth connection point (15) to a sixth connection point (16), the main loop (A) having: - a first pressure reducer (31) arranged between the first connection point (11) and the storage device (2); - a second pressure reducer (22) arranged between the fifth connection point (15) and a second exchanger (22), and the third bypass branch (D) having a third pressure reducer (33) and a third heat exchanger (23).

Description

THERMAL CONDITIONING SYSTEM technical field [1] The present invention relates to the field of thermal conditioning systems. Such systems can, for example, be fitted to motor vehicles. These systems ensure thermal regulation of various components, such as the passenger compartment or an electrical energy storage battery, when the vehicle is electrically powered. Heat exchange is managed primarily by the compression and expansion of a refrigerant circulating in a circuit containing several heat exchangers. A compressor forces the refrigerant to a high pressure and circulate it through the circuit. Previous technique [2] The refrigerant circuit typically comprises a main loop and several branch lines, allowing for multiple refrigerant circulation combinations. Numerous operating modes can thus be achieved, such as cooling the passenger compartment air, heating the passenger compartment air, dehumidifying the passenger compartment air, or cooling the vehicle's batteries. It is well known that a heat exchanger can be installed downstream of the compressor, capable of functioning as a condenser, meaning it can condense the high-pressure, high-temperature refrigerant at the compressor outlet. [3] It is also known to install, downstream of this condenser, a heat exchanger to ensure subcooling of the refrigerant, in order to improve the thermodynamic performance of the thermal conditioning system. However, adding such a heat exchanger can be difficult or even impossible. [4] There is therefore a need for systems with improved performance in all operating modes without the use of a subcooling exchanger. Summary [5] To this end, the present invention proposes a thermal conditioning system for a motor vehicle comprising a refrigerant circuit configured to circulate a refrigerant, the refrigerant circuit comprising: A main loop comprising successively, according to the direction of refrigerant flow: -- a compressor, -- a first heat exchanger configured to exchange heat with a first heat transfer fluid, -- a refrigerant fluid accumulation device, -- a second heat exchanger configured to exchange heat with an outside airflow to a vehicle passenger compartment, A first branch connecting a first connection point located on the main loop between the first heat exchanger and the refrigerant accumulation device to a second connection point located on the main loop between the second heat exchanger and a compressor inlet, A second branch connecting a third connection point located on the main loop between the first connection point and the refrigerant storage device to a fourth connection point located on the main loop between the refrigerant storage device and the second heat exchanger, - A third branch connecting a fifth connection point located on the main loop between the refrigerant accumulation device and the fourth connection point to a sixth connection point located on the main loop between the second connection point and the compressor inlet, in which the main loop comprises: - a first expansion device arranged between the first connection point and an inlet of the refrigerant fluid accumulation device, - a second release device located between the fifth point of connection and the second heat exchanger, and in which the third branch branch includes a third expansion device and a third heat exchanger configured to operate as an evaporator. [6] This configuration allows for a first stage of expansion of the refrigerant between the outlet of the first heat exchanger and the inlet of the storage device. The refrigerant, having undergone partial expansion, thus has a lower enthalpy than at the outlet of the first heat exchanger. The performance of the thermal conditioning system is therefore improved compared to operation without partial expansion. [7] The features listed in the following paragraphs can be implemented independently of each other or in any technically possible combination: [8] According to one embodiment of the thermal conditioning system, the first heat transfer fluid is an airflow from inside a passenger compartment of a motor vehicle. [9] According to one embodiment of the thermal conditioning system, the first heat transfer fluid is a heat transfer fluid. The thermal conditioning system includes a heat transfer fluid circuit configured to circulate a heat transfer fluid. The first heat exchanger is a two-fluid heat exchanger arranged jointly on the refrigerant circuit and on the heat transfer fluid circuit so as to permit heat exchange between the refrigerant and the heat transfer fluid.

[0010] The third heat exchanger, for example, is configured to exchange heat with an airflow from inside the vehicle's passenger compartment.

[0011] The refrigerant accumulation device is a desiccant bottle.

[0012] According to a first embodiment of the thermal conditioning system, the first expansion device is disposed on the main loop between the first connection point and the third connection point, and the second decompression device is located on the main loop between the fifth connection point and the fourth connection point.

[0013] The first pressure-reducing device is a calibrated orifice. The second pressure-reducing device is an electronic regulator.

[0014] The second branch of the bypass includes a fourth decompression device.

[0015] The fourth release device is a calibrated orifice.

[0016] The use of calibrated orifices makes it possible to achieve the first level of expansion, between the first heat exchanger and the desiccant bottle, by an inexpensive component.

[0017] According to a second embodiment of the thermal conditioning system, the first expansion device is disposed on the main loop between the first connection point and the third connection point, and the second expansion device is disposed on the main loop between the fourth connection point and the second heat exchanger.

[0018] The first pressure-reducing device is a calibrated orifice. The second pressure-reducing device is an electronic regulator.

[0019] According to a third embodiment of the thermal conditioning system, the first expansion device is disposed on the main loop between the third connection point and an inlet of the refrigerant fluid accumulation device, and the second expansion device is disposed on the main loop between the fifth connection point and the fourth connection point.

[0020] The first pressure-reducing device is an electronic regulator. The second pressure-reducing device is an electronic regulator.

[0021] The use of electronic regulators allows the amplitude of the first level of relaxation to be adapted in real time to all conditions encountered.

[0022] According to a fourth embodiment of the thermal conditioning system, the first expansion device is disposed on the main loop between the first connection point and the third connection point, and the second expansion device is located on the main loop between the fourth connection point and the second heat exchanger.

[0023] The first pressure-reducing device is an electronic regulator. The second pressure-reducing device is an electronic regulator.

[0024] According to one aspect of the thermal conditioning system, the second branch branch includes a first check valve configured to block refrigerant flow from the third connection point to the fourth connection point.

[0025] The first check valve prevents the high-pressure refrigerant fluid entering the storage device from flowing back towards the fourth connection point by circulating in the second branch of the bypass.

[0026] According to one implementation example, the main loop includes a second check valve configured to block refrigerant flow from the sixth connection point to the second connection point.

[0027] According to one embodiment, the main loop includes a third check valve configured to block refrigerant flow from the fourth connection point to the fifth connection point.

[0028] According to one implementation example, the third branch branch includes a fourth check valve configured to block refrigerant flow from the eighth connection point to the third heat exchanger.

[0029] The main loop includes a shut-off valve located between the second connection point and the sixth connection point.

[0030] According to one embodiment of the thermal conditioning system, the main loop includes a first internal heat exchanger configured to allow heat exchange between the refrigerant downstream of the first expansion device and the refrigerant downstream of the second heat exchanger.

[0031] The first internal heat exchanger ensures superheating of the refrigerant at the compressor inlet, thus preventing the presence of liquid refrigerant droplets at the compressor inlet.

[0032] According to one variant, the third branch of the bypass includes a second internal heat exchanger configured to allow heat exchange between the refrigerant upstream of the third expansion device and the refrigerant downstream of the third heat exchanger.

[0033] The second internal heat exchanger increases the enthalpy change between the inlet and outlet of the third heat exchanger, improving cooling performance.

[0034] According to one embodiment, the thermal conditioning system includes a fourth branch in parallel with the third expansion device and the third heat exchanger, the fourth branch comprising a fifth expansion device and a fourth heat exchanger.

[0035] The fourth branch connects a seventh connection point located on the third branch between the fifth connection point and the third expansion device to an eighth connection point located on the third branch between the third heat exchanger and the sixth connection point.

[0036] According to one embodiment, the fourth heat exchanger is thermally coupled with an element of a motor vehicle's powertrain.

[0037] The fourth heat exchanger thus makes it possible to ensure control of the operating temperature of the element of the vehicle's powertrain.

[0038] The vehicle's electric powertrain component may include an electrical energy storage battery.

[0039] The battery can provide the energy needed to power the vehicle.

[0040] The vehicle's electric powertrain component may include a vehicle traction electric motor.

[0041] The vehicle's electric powertrain component may include an electronic control unit for the vehicle's electric traction motor.

[0042] The fourth heat exchanger is thermally coupled to the element via a heat transfer fluid circulating in a secondary heat transfer fluid loop.

[0043] The heat transfer fluid circulating in the secondary heat transfer fluid loop can be a dielectric fluid.

[0044] According to one embodiment, the fourth heat exchanger is in contact with the vehicle's drivetrain element.

[0045] The heat transfer fluid circuit may include a fifth heat exchanger configured to exchange heat with an internal airflow to a vehicle passenger compartment.

[0046] The thermal conditioning system may include a three-way valve arranged jointly on the main loop and on the first branch, the three-way valve being configured to selectively: - allow refrigerant to flow from the first heat exchanger to the third connection point and prohibit refrigerant to flow from the first heat exchanger to the second connection point, or - allow refrigerant flow from the outlet of the first exchanger to the second connection point and prohibit refrigerant flow from the outlet of the first exchanger to the third connection point.

[0047] According to one implementation example, the three-way valve and the first pressure-reducing device form a single unit.

[0048] This facilitates integration into the thermal conditioning system.

[0049] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called heating mode, in which: - a flow of low-pressure refrigerant circulates in the compressor where it is increased in pressure, then circulates successively in the first heat exchanger, transferring heat to the first heat transfer fluid, in the first expansion device where it undergoes expansion to an intermediate pressure, in the second heat exchanger, in the refrigerant accumulation device, in the second expansion device where it goes to low pressure, in the second heat exchanger where it evaporates by absorbing heat from the outside airflow, and returns to the compressor.

[0050] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called cooling mode, in which: - a flow of low-pressure refrigerant circulates in the compressor where it passes to high pressure, then circulates successively in the first heat exchanger giving up heat to the first heat transfer fluid in the first bypass branch, in the second heat exchanger in the second expansion device where it undergoes expansion to an intermediate pressure, in the second bypass branch, in the refrigerant accumulation device, in the third bypass branch, in the third expansion device where it passes to low pressure, in the third heat exchanger where it evaporates absorbing heat, and returns to the compressor.

[0051] The invention also relates to a method of operating a thermal conditioning system according to another embodiment, in a so-called cooling mode, in which: - a flow of low-pressure refrigerant circulates in the compressor where it passes to high pressure, then circulates successively in the first heat exchanger giving up heat to the first heat transfer fluid, in the first bypass branch, in the second heat exchanger, in the second bypass branch, in the second expansion device where it undergoes expansion to an intermediate pressure, in the refrigerant accumulation device, in the third bypass branch, in the third expansion device where it passes to low pressure, in the third heat exchanger where it evaporates absorbing heat, and returns to the compressor. Brief description of the drawings

[0052] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached drawings, on which:

[0053] [Fig. 1] is a schematic view of a thermal conditioning system according to a first embodiment of the invention,

[0054] [Fig. 2] is a schematic view of a thermal conditioning system according to a variant of the first embodiment of the invention,

[0055] [Fig. 3] is a schematic view of a thermal conditioning system according to a second embodiment of the invention,

[0056] [Fig. 4] is a schematic view of a thermal conditioning system according to a third embodiment of the invention,

[0057] [Fig. 5] is a schematic view of a thermal conditioning system according to a fourth embodiment of the invention,

[0058] [Fig. 6] is a schematic view of a thermal conditioning system according to a variant of the third embodiment of the invention,

[0059] [Fig. 7] is a schematic view of the thermal conditioning system according to the second embodiment, operating according to a first operating mode, called the heating mode,

[0060] [Fig. 8] is a schematic view of the thermal conditioning system according to the second embodiment, operating according to a second mode of operation, called the cooling mode,

[0061] [Fig. 9] is a schematic view of the thermal conditioning system according to the third embodiment, operating according to a second operating mode, called the cooling mode,

[0062] [Fig. 10] is a pressure, enthalpy diagram of a thermal conditioning system in particular according to the second embodiment, operating according to the second operating mode, called cooling mode. Description of the implementation methods

[0063] To facilitate the reading of the figures, the different elements are not necessarily drawn to scale. In these figures, identical elements have the same reference numbers. Some elements or parameters may be indexed, that is, designated, for example, as first element or second element, or first parameter and second parameter, etc. This indexing aims to differentiate between similar, but not identical, elements or parameters. This indexing does not imply any priority of one element or parameter over another, and the designations can be interchanged.

[0064] In the following description, the term "a first element upstream of a second element" means that the first element is located before the second element relative to the direction of flow, or path, of a fluid. Similarly, the term "a first element downstream of a second element" means that the first element is located after the second element relative to the direction of flow, or path, of the fluid in question. In the case of a refrigerant circuit, the term "a first element upstream of a second element" means that the refrigerant flows successively through the first element, then the second element, without passing through the compression device, also known as the compressor. In other words, the refrigerant exits the compressor, possibly passes through one or more elements, then passes through the first element, then the second element, and then returns to the compressor, possibly after passing through other elements.

[0065] The term "a second element is placed between a first element and a third element" means that the shortest path from the first element to the third element passes through the second element.

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

[0067] An electronic control unit 45 receives information from various sensors, notably measuring the characteristics of the refrigerant at different points in the circuit. The electronic control unit 45 also receives instructions from the vehicle occupants, such as the desired temperature inside the passenger compartment. The electronic control unit 45 can also receive instructions from other electronic subsystems, such as For example, the electrical energy storage battery management system. The electronic control unit 45 implements control laws enabling the control of the various actuators, in order to ensure the control of the thermal conditioning system 100 so as to ensure the received instructions.

[0068] The refrigerant circuit 10 forms a closed loop through which the refrigerant can circulate. The refrigerant circuit 10 is leak-proof when it is in its nominal operating condition, that is, without any faults or leaks. Each connection point of the circuit 10 allows the refrigerant to flow into one of the circuit sections that converge at that connection point. The distribution of the refrigerant between the circuit sections that converge at a connection point is achieved by opening or closing the shut-off valves, check valves, or expansion devices located on each branch. In other words, each connection point is a means of redirecting the refrigerant arriving at that connection point.Various shut-off valves and check valves thus allow the refrigerant to be selectively directed into the different branches of the refrigerant circuit, in order to ensure different modes of operation, as will be described later.

[0069] The refrigerant used by the refrigerant circuit 10 is a chemical fluid such as R1234yf. Other refrigerants can also be used instead, such as R134a or R290.

[0070] The term "interior airflow Fi" refers to the airflow directed towards the passenger compartment of a motor vehicle. This interior airflow Fi may circulate within a heating, ventilation, and / or air conditioning (HVAC) system. This system is not shown in the various figures. A first fan-motor unit, also not shown, is located within the HVAC system to increase the flow rate of the interior airflow Fi as needed.

[0071] External airflow Fe refers to airflow that is not directed into the vehicle's passenger compartment. In other words, this airflow Fe remains outside the vehicle's passenger compartment. A second fan motor assembly, also not shown, can be activated to increase the flow rate of the external airflow Fe if necessary. The flow rate ensured by the first motor-fan group as well as by the second motor-fan group can be adjusted in real time according to the heat exchange requirements, for example by the electronic control unit 45 of the thermal conditioning system 100.

[0072] The term "exchanger" is equivalent to the term "heat exchanger", and the two terms may be used interchangeably in the description that follows.

[0073] The present invention proposes a thermal conditioning system 100 for motor vehicles, comprising a refrigerant fluid circuit 10 configured to circulate a refrigerant fluid. The refrigerant circuit 10 comprises: A main loop A comprising successively, according to the direction of refrigerant flow: - a compressor 1, - a first heat exchanger 21 configured to exchange heat with a first heat transfer fluid F1, - a refrigerant fluid accumulation device 2, - a second heat exchanger 22 configured to exchange heat with an external airflow Fe to a vehicle passenger compartment, A first branch branch B connecting a first connection point 11 arranged on the main loop A between the first heat exchanger 21 and the refrigerant fluid accumulation device 2 to a second connection point 12 arranged on the main loop A between the second heat exchanger 22 and an inlet 1a of the compressor 1, A second branch C connecting a third connection point 13 located on the main loop A between the first connection point 11 and the refrigerant fluid storage device 2 to a fourth connection point 14 located on the main loop A between the refrigerant fluid storage device 2 and the second heat exchanger 22, - A third branch branch D connecting a fifth connection point 15 located on the main loop A between the refrigerant fluid storage device 2 and the fourth connection point 14 to a sixth point of connection 16 arranged on the main loop A between the second connection point 12 and the inlet 1 a of compressor 1. The main loop A includes: - a first expansion device 31 disposed between the first connection point 11 and an inlet 2a of the refrigerant fluid accumulation device 2, - a second expansion device 32 arranged between the fifth connection point 15 and the second heat exchanger 22. The third branch branch D includes a third expansion device 33 and a third heat exchanger 23 configured to operate as an evaporator.

[0074] This configuration allows for a partial expansion of the refrigerant between the outlet of the first heat exchanger 21 and the inlet of the storage device 2. The refrigerant, having undergone this partial expansion, thus has a lower enthalpy than at the outlet of the first heat exchanger 21. This difference in enthalpy improves the performance of the thermal conditioning system, notably by increasing the maximum cooling capacity.

[0075] Figure 1 represents a first embodiment of the thermal conditioning system 100. The first heat transfer fluid F1 is an interior airflow Fi to the passenger compartment of a motor vehicle. The first heat exchanger 21 is an internal condenser and is located within the vehicle's heating, ventilation, and / or air conditioning system.

[0076] According to a variant of the first embodiment, illustrated in Figure 2, the first heat transfer fluid F1 is a heat transfer liquid. The thermal conditioning system includes a heat transfer fluid circuit 40 configured to circulate a heat transfer fluid. The first heat exchanger 21 is a two-fluid heat exchanger arranged jointly on the refrigerant circuit 10 and on the heat transfer fluid circuit 40 so as to allow heat exchange between the refrigerant and the heat transfer fluid.

[0077] The heat transfer fluid circuit 40 includes a fifth heat exchanger 25 configured to exchange heat with an interior airflow Fi to a vehicle passenger compartment. The fifth heat exchanger 25 is located within the heating, ventilation, and / or air conditioning system. The fluid circuit The heat transfer fluid 40 includes a heat transfer fluid circulation pump 42. The pump 42 can be selectively switched on and off, for example by a command from the electronic control unit 45. The heat transfer fluid circuit 40 also includes a sixth heat exchanger, not shown, configured to exchange heat with the outside airflow Fe.

[0078] In the first embodiment, as in its variant, the first heat exchanger 21 is a condenser. Depending on the embodiment, the heat supplied by the condensation of the refrigerant is dissipated into the internal airflow Fi, or into the heat transfer fluid of the circuit 40.

[0079] When the heat released by the condensation of the refrigerant in the first heat exchanger 21 is dissipated into the interior airflow Fi, the passenger compartment heating is said to be direct. When the heat released by the condensation of the refrigerant in the first heat exchanger 21 is dissipated first into the heat transfer fluid of the circuit 40, and then into the interior airflow Fi via the fifth heat exchanger 25, the passenger compartment heating is said to be indirect.

[0080] The second heat exchanger 22 is an evaporator-condenser. In other words, the second heat exchanger 22 can selectively operate either as an evaporator or as a condenser.

[0081] In the examples shown, the third heat exchanger 23 is configured to exchange heat with an airflow Fi from inside the vehicle's passenger compartment. The third heat exchanger 23 is an evaporator located within the heating, ventilation, and / or air conditioning system.

[0082] The refrigerant storage device 2 is a desiccant bottle. The term "storage device" is equivalent to the term "refrigerant storage device".

[0083] The desiccant bottle 2 can receive a two-phase mixture of refrigerant at its inlet 2a. In steady state, the refrigerant arriving at the inlet of the desiccant bottle is in a saturated liquid state and the refrigerant leaving the outlet 2b of the desiccant bottle is in a saturated liquid state.

[0084] According to the variant of the first embodiment illustrated in Figure 2, as well as in the other embodiments illustrated, the thermal conditioning system 100 includes a fourth branch E in parallel with the third expansion device 33 and the third heat exchanger 23, the fourth branch E including a fifth expansion device 35 and a fourth heat exchanger 24. This fourth branch E and the associated components is optional.

[0085] The fourth branch E connects a seventh connection point 17 arranged on the third branch D between the fifth connection point 15 and the third expansion device 33 to an eighth connection point 18 arranged on the third branch D between the third heat exchanger 23 and the sixth connection point 16.

[0086] The fourth heat exchanger 24 is thermally coupled to a component 30 of a motor vehicle's powertrain. The fourth heat exchanger 24 thus enables control of the operating temperature of the component 30 of the vehicle's powertrain.

[0087] Element 30 of the vehicle's electric powertrain may include an electrical energy storage battery. The battery can provide the energy required to propel the vehicle.

[0088] Element 30 of the vehicle's electric powertrain may include a vehicle electric traction motor. Element 30 of the vehicle's electric powertrain may include an electronic control unit for the vehicle electric traction motor.

[0089] The fourth heat exchanger 24 is thermally coupled to the element 30 via a heat transfer fluid circulating in a secondary loop 41. The heat transfer fluid circulating in the secondary loop 41 can be a dielectric fluid. Alternatively, the heat transfer fluid circulating in the secondary loop 41 can be a mixture of water and glycol.

[0090] According to another embodiment, the fourth heat exchanger 24 is in contact with the element 30 of the vehicle's powertrain. A wall of the The fourth heat exchanger 24 is thus in contact with a wall of the first element 25. A paste intended to improve heat transfer between the two walls can be placed between these two walls.

[0091] According to the first embodiment of the thermal conditioning system 100, illustrated in Figure 1, the first expansion device 31 is arranged on the main loop A between the first connection point 11 and the third connection point 13. The second expansion device 32 is arranged on the main loop A between the fifth connection point 15 and the fourth connection point 14.

[0092] The first expansion device 31 is, in this first embodiment, a calibrated orifice. A calibrated orifice is a passive component. A calibrated orifice has a constant passage area, which cannot be modified over time. The second expansion device 32 is an electronic expansion valve. In an electronic expansion valve, the passage area allowing the refrigerant to pass through can be continuously adjusted between a closed position and a maximum open position. For this purpose, the control unit 45 of the thermal conditioning system 100 can, for example, drive an electric motor that moves a movable shutter controlling the passage area available to the refrigerant. Controlling the position of the movable shutter allows the expansion to be controlled. The expansion of the refrigerant in the second expansion device 32 can be modified in real time.

[0093] The second branch of the C branch includes a fourth release device 34. The fourth release device 34 is here a calibrated orifice.

[0094] The use of calibrated orifices makes it possible to achieve the first level of expansion, between the first heat exchanger 21 and the desiccant bottle 2, by an inexpensive component.

[0095] Figure 3 shows a second embodiment of the thermal conditioning system 100. In this embodiment, the first expansion device 31 is located on the main loop A between the first connection point 11 and the third connection point 13. The second device expansion valve 32 is located on the main loop A between the fourth connection point 14 and the second heat exchanger 22.

[0096] The first pressure-reducing device 31 is a calibrated orifice. The second pressure-reducing device 32 is an electronic pressure regulator. In this embodiment, the second branch C does not have a pressure-reducing device.

[0097] Figure 4 shows a third embodiment of the thermal conditioning system 100. In this third embodiment, the first expansion device 31 is located on the main loop A between the third connection point 13 and an inlet 2a of the refrigerant storage device 2. The second expansion device 32 is located on the main loop A between the fifth connection point 15 and the fourth connection point 14. In this embodiment, the second branch C does not have an expansion device.

[0098] The first pressure-reducing device 31 is an electronic pressure regulator. The second pressure-reducing device 32 is an electronic pressure regulator.

[0099] The use of electronic expansion valves allows the partial expansion of the refrigerant to be adapted in real time to all operating conditions. This optimizes the operation of the thermal conditioning system.

[0100] Figure 5 represents a fourth embodiment of the thermal conditioning system 100. According to this fourth embodiment of the thermal conditioning system 100, the first expansion device is located on the main loop A between the first connection point 11 and the third connection point 13. The second expansion device is located on the main loop A between the fourth connection point 14 and the second heat exchanger 22. In this embodiment, the second branch C does not have an expansion device.

[0101] The first pressure-reducing device 31 is an electronic pressure regulator. The second pressure-reducing device 32 is an electronic pressure regulator.

[0102] Of the four main embodiments presented and their associated variants, the second branch of derivation C comprises a first The first check valve 3 is configured to block refrigerant flow from the third connection point 13 to the fourth connection point 14. The first check valve 3 prevents the high-pressure refrigerant inlet to the storage device 2 from flowing back to the fourth connection point 14 by circulating in the second branch of the bypass C. The first check valve 3 is configured to allow refrigerant flow from the fourth connection point 14 to the third connection point 13.

[0103] Of the four illustrated embodiments and associated variants, the main loop A includes a second check valve 4 configured to block refrigerant flow from the sixth connection point 16 to the second connection point 12. The second check valve 4 is configured to allow refrigerant flow from the second connection point 12 to the sixth connection point 16.

[0104] According to the second and fourth embodiments, illustrated respectively in Figure 3 and Figure 5, the main loop A includes a third check valve 5 configured to block refrigerant flow from the fourth connection point 14 to the fifth connection point 15. The third check valve 5 is configured to allow refrigerant flow from the fifth connection point 15 to the fourth connection point 14.

[0105] According to the illustrated embodiments, the third branch branch D includes a fourth check valve 9 configured to block refrigerant flow from the eighth connection point 18 to the third heat exchanger 23. The fourth check valve 9 is configured to allow refrigerant flow from the third heat exchanger 23 to the eighth connection point 18.

[0106] In some unshown variants, each non-return valve 3, 4, 5, 9 can be replaced by a shut-off valve. The shut-off valve(s) are electrically controlled, for example by the electronic control unit 45.

[0107] The main loop A includes a shut-off valve 6 located between the second connection point 12 and the sixth connection point 16. The shut-off valve 6 allows the refrigerant fluid circulation in the main loop A to be selectively interrupted, from the second connection point 12 to the sixth connection point 16. The refrigerant circulating in the first branch B then flows from the second connection point 12 to the fourth connection point 14 through the second heat exchanger 22. The shut-off valve 6 is present in all the illustrated embodiments.

[0108] According to a variant of the third embodiment of the thermal conditioning system 100, illustrated in Figure 6, the main loop A includes a first internal heat exchanger 7 configured to allow heat exchange between the refrigerant downstream of the first expansion device 31 and the refrigerant downstream of the second heat exchanger 22.

[0109] The first internal heat exchanger 7 ensures superheating of the refrigerant fluid at the inlet of the compressor 1, i.e. avoids the presence of droplets of liquid refrigerant at the inlet of the compressor 1.

[0110] The first internal heat exchanger 7 comprises a first heat exchange section 7a located on the main loop A downstream of the fifth connection point 15 and upstream of the second expansion valve 32, and a second heat exchange section 7b located on the main loop A downstream of the second connection point 12. The first internal heat exchanger 7 is configured to allow heat exchange between the refrigerant in the first heat exchange section 7a and the refrigerant in the second heat exchange section 7b. The refrigerant circulating at high pressure in the main loop A can thus transfer heat to the refrigerant circulating at a lower pressure in the main loop A, after being expanded in the second expansion valve 32 and passing through the second heat exchanger 22.

[0111] In this variant, the third branch D also includes a second internal heat exchanger 8 configured to allow heat exchange between the refrigerant upstream of the third expansion device 33 and the refrigerant downstream of the third heat exchanger 23. The second internal heat exchanger 8 increases the enthalpy change between The inlet and outlet of the third heat exchanger 23 improve cooling performance. When the fourth heat exchanger 24 is used, the second internal heat exchanger 8 also improves its performance.

[0112] The second internal heat exchanger 8 comprises a first heat exchange section 8a located on the third branch of the bypass D upstream of the third expansion valve 33 and a second heat exchange section 8b located on the third branch of the bypass D downstream of the third heat exchanger 23. The second internal heat exchanger 8 is configured to allow heat exchange between the refrigerant in the first heat exchange section 8a and the refrigerant in the second heat exchange section 8b. The refrigerant circulating at high pressure in the third branch of the bypass D can thus transfer heat to the refrigerant circulating at a lower pressure in the third branch of the bypass D, after expansion in the third expansion valve 33.

[0113] The two internal heat exchangers 7, 8 can be added to the thermal conditioning system according to the first, second and third embodiment.

[0114] In unrepresented variants, the thermal conditioning system 100 comprises a single internal heat exchanger. This single internal heat exchanger may be the first internal exchanger 7, or the second internal exchanger 8.

[0115] Depending on the embodiment, the refrigerant from the first heat exchanger 21 and arriving at the first connection point 11 can be directed to the first branch branch B, or continue to circulate in the main loop A. For this, different types of valves can be used.

[0116] The thermal conditioning system 100 may include a three-way valve 20 installed on both the main loop A and the first branch B. The three-way valve 20 is configured to selectively: - allow refrigerant flow from the outlet of the first heat exchanger 21 to the third connection point 13 and prohibit refrigerant flow refrigerant at the outlet of the first heat exchanger 21 to the second connection point 12, or - allow circulation of the refrigerant from the outlet of the first exchanger 21 to the second connection point 12 and prohibit circulation of the refrigerant from the outlet of the first exchanger 21 to the third connection point 13.

[0117] The three-way valve 20 is present in the first, second, and fourth embodiments, illustrated respectively in Figures 1, 3, and 5. In one implementation example, the three-way valve 20 and the first pressure-reducing device 31 form a single unit. This facilitates integration into the thermal conditioning system.

[0118] Instead of the three-way valve 20, the thermal conditioning system 100 can include two two-way valves 19a, 19b. The first two-way valve 19a is located on the main loop A between the first connection point 11 and the third connection point 13. The second two-way valve 19b is located on the first branch line B. The second two-way valve 19b is located between the first connection point 11 and the second connection point 12. Each two-way valve 19a, 19b is electrically controlled. Each two-way valve 19a, 19b selectively allows fluid communication between its inlet and outlet, or prevents fluid communication between its inlet and outlet. Each two-way valve 19a, 19b is a refrigerant circulation shut-off valve.The combination of the two stop valves 19a, 19b is present on the variant of the first embodiment and on the third embodiment, illustrated respectively in Figure 2 and Figure 4.

[0119] We will now describe some possible operating modes of the thermal conditioning system 100.

[0120] Figure 7 represents an operating method of a thermal conditioning system 100 according to the second embodiment, in a so-called heating mode, in which: - a flow Qr of low-pressure refrigerant circulates in compressor 1 where it is subjected to high pressure, then circulates successively in the first heat exchanger 21 by transferring heat to the first heat transfer fluid F1, in the first expansion device 31 where it undergoes expansion to an intermediate pressure, in the second heat exchanger 22, in the refrigerant fluid accumulation device 2, in the second expansion device 32 where it passes to low pressure, in the second heat exchanger 22 where it evaporates by absorbing heat from the outside airflow Fe, and returns to the compressor 1.

[0121] When the thermal conditioning system 100 operates according to this mode of operation, the second heat exchanger 22 flows through it in a first direction. This mode of operation has been illustrated based on the second embodiment and is applicable to all embodiments.

[0122] In this heating method, the heat from the outside airflow Fe contributes to heating the vehicle's interior. The intermediate expansion achieved by the first expansion device 31 increases the amount of heat extracted from the outside airflow Fe.

[0123] Figure 8 represents an operating method of a thermal conditioning system 100 according to the second embodiment, in a so-called cooling mode, in which: - a flow Qr' of low-pressure refrigerant circulates in the compressor 1 where it passes to high pressure, then circulates successively in the first heat exchanger 21 giving heat to the first heat transfer fluid F1, in the first bypass branch B, in the second heat exchanger 22, in the second expansion device 32 where it undergoes expansion to an intermediate pressure, in the second bypass branch C, in the refrigerant accumulation device 2, in the third bypass branch D, in the third expansion device 33 where it passes to low pressure, in the third heat exchanger 23 where it evaporates absorbing heat, and returns to the compressor 1.

[0124] When the thermal conditioning system 100 operates in the so-called cooling mode, the second heat exchanger 22 flows through it in the opposite direction to the first direction of flow. Monitoring in heating mode. The refrigerant undergoes a first expansion between the outlet of the first heat exchanger 21 and the inlet of the storage device 22, both during operation in heating mode and during operation in cooling mode. All embodiments allow for partial expansion of the refrigerant downstream of the first heat exchanger 21 and upstream of the refrigerant storage device 2.

[0125] The three-way valve 11 directs the refrigerant flow Qr' from the first heat exchanger 21 to the first branch branch B. The refrigerant does not flow between the first connection point 11 and the third connection point 13. At the second connection point 12, the refrigerant joins the main loop A and flows through the second heat exchanger 22. The shut-off valve 6 is in the closed position and prevents the refrigerant from flowing to the sixth connection point 16. The refrigerant, having exchanged heat with the outside air flow Fe at the second heat exchanger 22, undergoes an intermediate expansion as it passes through the second expansion valve 32. At the fourth connection point 14, the third check valve 5 prevents the refrigerant from flowing to the fifth connection point 15.The refrigerant flows through the second branch line C, rejoins the main loop A at the third connection point 13, and passes through the storage tank 2. The refrigerant then flows through the third branch line D and reaches the third expansion valve 33, where it undergoes expansion, reducing its pressure from intermediate to low. The refrigerant evaporates in the third heat exchanger 23, rejoins the main loop A at the sixth connection point 16, and enters the compressor inlet 1a, thus completing the thermodynamic cycle.

[0126] Figure 10 illustrates this operating process with a pressure-enthalpy diagram. Point p1a represents the state of the refrigerant at low pressure P0 at the inlet of compressor 1. Point p1b represents the state of the refrigerant at high pressure P2 and high temperature at the outlet of compressor 1. Point p2b represents the state of the refrigerant at the outlet of the receiver-drier 2. Point p2b lies on the saturation curve S characteristic of the refrigerant used, for the intermediate pressure P1. Point p23 corresponds to the state of the Refrigerant fluid at the inlet of the third heat exchanger 23. Arrow Q23 represents the enthalpy change of the refrigerant fluid during its evaporation in the third heat exchanger 23. The cooling capacity of the indoor airflow Fi is proportional to the quantity represented by Q23. Arrow Q23' represents the enthalpy change of the refrigerant fluid for an air conditioning system that does not allow for an intermediate expansion between the outlet of the first heat exchanger 21 and receiver 2. In such a system, the enthalpy of the refrigerant fluid at the outlet of receiver 2 corresponds to the saturation point at pressure P2. The dashed arrow represents the expansion phase by the third expansion valve 33. In such a case, the enthalpy change is less than in the thermal air conditioning system proposed here. The available cooling capacity is also lower.Arrow G schematically represents the gain obtained on the enthalpy variation thanks to the intermediate expansion achieved by the proposed thermal conditioning system.

[0127] Figure 9 represents an operating method of a thermal conditioning system 100 according to the third embodiment, in a so-called cooling mode, in which: - a flow Qr” of low-pressure refrigerant circulates in the compressor 1 where it passes to high pressure, then circulates successively in the first heat exchanger 21 giving up heat to the first heat transfer fluid F1, in the first bypass branch B, in the second heat exchanger 22, in the second bypass branch C, in the second expansion device 32 where it undergoes expansion to an intermediate pressure, in the refrigerant storage device 2, in the third bypass branch D, in the third expansion device 33 where it passes to low pressure, in the third heat exchanger 23 where it evaporates absorbing heat, and returns to the compressor 1.

[0128] The second two-way valve 19b is open while the first two-way valve 19a is closed. At the first connection point 11, the refrigerant exiting the compressor 1 at high pressure and high temperature flows into the first bypass branch B. The shut-off valve 6 is closed, so that at the second connection point 12 the refrigerant is redirected to the main loop A and condenses at the second heat exchanger 22, dissipating heat into the outside airflow Fe. The second expansion valve 32 is in the closed position, so the refrigerant, having undergone heat exchange in the second heat exchanger 22, enters the second bypass branch C at the fourth connection point 14. The first expansion device 31 performs a partial expansion of the refrigerant before it enters the receiver 2. The third expansion device 33 reduces the refrigerant to a low pressure, and the evaporation of the refrigerant at the third heat exchanger 23 cools the inside airflow Fi. The low-pressure refrigerant enters the compressor inlet 1a. At the sixth connection point 16, the second check valve 4 prevents the refrigerant from flowing back to the second connection point 12. Numerous other operating modes, not illustrated, are also possible. For example, it is possible to pass a flow of refrigerant in parallel through the third heat exchanger 3 and the fourth heat exchanger 4 so as to simultaneously cool the interior airflow Fi and the component 30 of the vehicle's powertrain. The respective opening degrees of the third expansion valve 33 and the fifth expansion valve 35 allow the cooling capacity to be distributed between these two heat exchangers.

Claims

Demands

1. A motor vehicle thermal conditioning system (100) comprising a refrigerant circuit (10) configured to circulate a refrigerant, the refrigerant circuit (10) comprising: A main loop (A) comprising successively, according to the direction of circulation of the refrigerant: -- a compressor (1), -- a first heat exchanger (21) configured to exchange heat with a first heat transfer fluid (F1), -- a refrigerant fluid accumulation device (2), -- a second heat exchanger (22) configured to exchange heat with an airflow (Fe) external to a vehicle passenger compartment, A first branch branch (B) connecting a first connection point (11) located on the main loop (A) between the first exchanger (21) and the refrigerant fluid accumulation device (2) at a second connection point (12) disposed on the main loop (A) between the second heat exchanger (22) and an inlet (1 a) of the compressor (1 ), A second branch branch (C) connecting a third connection point (13) located on the main loop (A) between the first connection point (11) and the refrigerant fluid storage device (2) to a fourth connection point (14) located on the main loop (A) between the refrigerant fluid storage device (2) and the second heat exchanger (22), - A third branch branch (D) connecting a fifth connection point (15) located on the main loop (A) between the refrigerant fluid storage device (2) and the fourth connection point (14) to a sixth connection point (16) located on the main loop (A) between the second connection point (12) and the inlet (1a) of the compressor (1), in which the main loop (A) comprises: - a first expansion device (31) disposed between the first connection point (11) and an inlet (2a) of the refrigerant fluid accumulation device (2), - a second expansion device (32) disposed between the fifth connection point (15) and the second heat exchanger (22), and in which the third branch branch (D) includes a third expansion device (33) and a third heat exchanger (23) configured to operate as an evaporator.

2. Thermal conditioning system (100) according to claim 1, wherein the first heat transfer fluid (F1) is a heat transfer fluid, the thermal conditioning system comprising a heat transfer fluid circuit (40) configured to circulate a heat transfer fluid, and wherein the first heat exchanger (21) is a two-fluid heat exchanger arranged jointly on the refrigerant fluid circuit (10) and on the heat transfer fluid circuit (40) so as to permit heat exchange between the refrigerant fluid and the heat transfer fluid.

3. Thermal conditioning system (100) according to claim 1 or 2, wherein the first expansion device (31) is a calibrated orifice disposed on the main loop (A) between the first connection point (11) and the third connection point (13), wherein the second expansion device (32) is an electronic expansion valve disposed on the main loop (A) between the fifth connection point (15) and the fourth connection point (14), and wherein the second branch (C) comprises a fourth expansion device (34).

4. Thermal conditioning system (100) according to claim 1 or 2, wherein the first expansion device (31) is a calibrated orifice disposed on the main loop (A) between the first connection point (11) and the third connection point (13), and wherein the second expansion device (32) is an electronic expansion valve disposed on the main loop (A) between the fourth connection point (14) and the second heat exchanger (22).

5. Thermal conditioning system (100) according to claim 1 or 2, wherein the first expansion device (31) is an electronic expansion valve disposed on the main loop (A) between the third connection point (13) and an inlet (2a) of the fluid storage device (2) refrigerant, and in which the second expansion device (32) is an electronic expansion valve disposed on the main loop (A) between the fifth connection point (15) and the fourth connection point (14).

6. Thermal conditioning system according to claim 1 or 2, wherein the second branch of bypass (C) includes a first check valve (3) configured to block a circulation of refrigerant fluid from the third connection point (13) to the fourth connection point (14).

7. Thermal conditioning system according to claim 1 or 2, wherein the main loop (A) includes a second check valve (4) configured to block refrigerant flow from the sixth connection point (16) to the second connection point (12), and / or a third check valve (5) configured to block refrigerant flow from the fourth connection point (14) to the fifth connection point (15).

8. Thermal conditioning system according to claim 1 or 2, wherein the third branch of bypass (D) includes a fourth check valve (9) configured to block refrigerant flow from the eighth connection point (18) to the third heat exchanger (23).

9. Thermal conditioning system (100) according to claim 1 or 2, wherein the first expansion device (31) is an electronic expansion valve disposed on the main loop (A) between the first connection point (11) and the third connection point (13), and wherein the second expansion device (32) is an electronic expansion valve disposed on the main loop (A) between the fourth connection point (14) and the second heat exchanger (22).

10. Thermal conditioning system (100) according to any one of the preceding claims, wherein the main loop (A) comprises a first internal heat exchanger (7) configured to permit heat exchange between the refrigerant downstream of the first expansion device (31) and the refrigerant downstream of the second heat exchanger (22), and wherein the third bypass branch (D) comprises a second internal heat exchanger (8) configured to permit heat exchange between the refrigerant upstream of the third expansion device (33) and the refrigerant downstream of the third heat exchanger (23).

11. Thermal conditioning system (100) according to any one of the preceding claims, comprising a fourth bypass branch (E) in parallel with the third expansion device (33) and the third heat exchanger (23), the fourth bypass branch (E) comprising a fifth expansion device (35) and a fourth heat exchanger (24), in which the fourth heat exchanger (24) is thermally coupled with an element (30) of a drive chain of a motor vehicle.

12. Thermal conditioning system (100) according to the preceding claims, comprising a three-way valve (20) disposed jointly on the main loop (A) and on the first branch (B), the three-way valve (20) being configured to selectively: - allow refrigerant to flow from the outlet of the first heat exchanger (21) to the third connection point (13) and prohibit refrigerant to flow from the outlet of the first heat exchanger (21) to the second connection point (12), or - allow circulation of the refrigerant from the outlet of the first exchanger (21) to the second connection point (12) and prohibit circulation of the refrigerant from the outlet of the first exchanger (21) to the third connection point (13), in which the three-way valve (20) and the first expansion device (31) form a single unit.

13. A method of operating a thermal conditioning system (100) according to any one of claims 1 to 12, in a so-called heating mode, in which: - a flow (Q) of low-pressure refrigerant circulates in the compressor (1) where it is subjected to high pressure, then circulates successively in the first heat exchanger (21) transferring heat to the first heat transfer fluid (F1), in the first expansion device (31) where it undergoes expansion to an intermediate pressure, in the second heat exchanger (22), in the refrigerant accumulation device (2), in the second expansion device (32) where it is subjected to low pressure, in the second heat exchanger (22) where it evaporates by absorbing heat from the outside airflow (Fe), and returns to the compressor (1).

14. A method of operating a thermal conditioning system (100) according to any one of claims 9 to 12 in combination with claim 7 or claim 9, in a so-called cooling mode, wherein: - a flow (Q) of low-pressure refrigerant circulates in the compressor (1) where it passes to high pressure, then circulates successively in the first heat exchanger (21) giving up heat to the first heat transfer fluid (F1), in the first bypass branch (B), in the second heat exchanger (22), in the second expansion device (32) where it undergoes expansion to an intermediate pressure, in the second bypass branch (C), in the refrigerant accumulation device (2), in the third bypass branch (D), in the third expansion device (33) where it passes to low pressure, in the third heat exchanger (23) where it evaporates absorbing heat, and returns to the compressor (1).

15. A method of operating a thermal conditioning system (100) according to any one of claims 9 to 12 in combination with claim 5, in a so-called cooling mode, wherein: - a flow (Q) of low-pressure refrigerant circulates in the compressor (1) where it passes to high pressure, then circulates successively in the first heat exchanger (21) giving up heat to the first heat transfer fluid (F1), in the first bypass branch (B), in the second heat exchanger (22), in the second bypass branch (C), in the second expansion device (32) where it undergoes expansion to an intermediate pressure, in the refrigerant storage device (2), in the third bypass branch (D), in the third expansion device (33) where it passes to low pressure, in the third heat exchanger (33) where it evaporates absorbing heat, and returns to the compressor (1).

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