Thermal conditioning system

Abstract

The invention relates to a thermal conditioning system (100), comprising: - a refrigerant circuit (10), - a compression device (7) having a first inlet (7A), a second inlet (7B) and an outlet (7C), - a liquid / vapor separator (5) having an inlet (5A), a first outlet (5B) and a second outlet (5C), in which the refrigerant circuit (10) has a main loop (A) comprising successively: - the first inlet (7A) and the outlet (7C) of the compression device (7), - a first heat exchanger (1) configured to exchange heat with a first fluid (F1), - a first expansion valve (21), - the inlet (5A) and the first outlet (5B) of the liquid / vapor separator (5), - a second expansion valve (22), - a second (2) and a third heat exchanger (2).and in which the second outlet (5C) of the liquid / vapor separation device (5) is connected to the second inlet (7B) of the compression device (7). Figure 1,

Description

Title of the invention: Thermal conditioning system technical field

[0001] 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 vehicle 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 into a high-pressure state, allowing its circulation within the circuit. The refrigerant can absorb or release heat at the various heat exchangers arranged in the circuit. Previous technique

[0002] A first heat exchanger receiving high-pressure refrigerant can be used to heat a first heat transfer fluid. A second heat exchanger receiving refrigerant from the first exchanger, and expanded to a low-pressure state, can be used to cool a second heat transfer fluid. A third heat exchanger, located downstream of the second heat exchanger, can be used to further cool the second fluid, or to cool a third fluid.

[0003] It is desirable to have thermal conditioning systems with improved efficiency, in particular offering increased thermal power. Summary

[0004] To this end, a thermal conditioning system is proposed, comprising: - a refrigerant circuit configured to circulate a refrigerant, - a compression device comprising a first inlet, a second inlet and an outlet, - a liquid / vapor separation device comprising an inlet, a first outlet and a second outlet, in which the refrigerant circuit comprises a main refrigerant circulation loop comprising successively, in a direction of refrigerant circulation: - the first input of the compression device, - the output of the compression device, - a first heat exchanger, - a first regulator, - the inlet of the liquid / vapor separation device, - the first output of the liquid / vapor separation device, - a second regulator, - a second heat exchanger, - a third heat exchanger, and in which the refrigerant circuit includes a first branch connecting the second outlet of the liquid / vapor separation device to the second inlet of the compression device.

[0005] The features listed in the following paragraphs can be implemented independently of each other or in any technically possible combination:

[0006] The thermal conditioning system is a thermal conditioning system for a motor vehicle.

[0007] The compression device is configured to supply refrigerant fluid at high pressure.

[0008] The first inlet of the compression device is configured to receive low-pressure refrigerant fluid.

[0009] The second inlet of the compression device is configured to receive intermediate pressure refrigerant fluid.

[0010] The compression device is configured so that the refrigerant admitted through the first inlet is discharged through the outlet, and the refrigerant admitted through the second inlet is also discharged through the outlet.

[0011] The inlet of the liquid / vapor separation device is configured to receive refrigerant in a two-phase state. A two-phase state is understood to mean a mixture of liquid and vapor.

[0012] The first outlet of the liquid / vapor separation device is configured to supply refrigerant fluid in the liquid state.

[0013] The second outlet of the liquid / vapor separation device is configured to supply refrigerant fluid in the gaseous state.

[0014] The liquid / vapor separation device is configured so that the refrigerant received at the inlet is distributed between the first outlet and the second outlet.

[0015] The first heat exchanger is configured to exchange heat with a first fluid.

[0016] The first fluid is, for example, an airflow inside the passenger compartment of a motor vehicle.

[0017] The first exchanger is thus configured to exchange heat with an airflow inside the passenger compartment of a motor vehicle.

[0018] According to one embodiment, the first heat exchanger is configured to exchange heat with a heat transfer fluid circulating in a closed heat transfer fluid circuit, the heat transfer fluid circuit comprising a heat exchanger configured to exchange heat with an airflow inside the vehicle's passenger compartment.

[0019] The first fluid is then a heat transfer fluid circulating in a closed heat transfer fluid circuit.

[0020] The first exchanger is configured to operate as a refrigerant fluid condenser.

[0021] The second heat exchanger is configured to exchange heat with a second fluid.

[0022] The second exchanger is thermally coupled with an element of an electric traction chain of a motor vehicle.

[0023] The second heat exchanger allows the element of the vehicle's electric traction chain to be cooled.

[0024] The second heat exchanger is thermally coupled with the element of the electric traction chain via a heat transfer fluid circulating in a heat transfer fluid circuit.

[0025] The second fluid is a heat transfer fluid circulating in the heat transfer fluid circuit.

[0026] The second exchanger is configured to operate as a refrigerant fluid evaporator.

[0027] The element of the vehicle's electric powertrain includes an electrical energy storage battery.

[0028] The vehicle's electric drivetrain element includes a vehicle electric traction motor.

[0029] The vehicle's electric drivetrain element includes an electronic control unit for the vehicle's electric traction motor.

[0030] The third heat exchanger is configured to exchange heat with a third fluid.

[0031] The third fluid is, for example, an airflow inside the passenger compartment of a motor vehicle.

[0032] The third exchanger is thus thermally coupled with an airflow inside the passenger compartment of a motor vehicle.

[0033] According to one embodiment, the third heat exchanger is configured to exchange heat with a heat transfer fluid circulating in a closed circuit of heat transfer fluid, the heat transfer fluid circuit comprising a heat exchanger configured to exchange heat with an airflow inside the vehicle's passenger compartment.

[0034] The third fluid is thus a heat transfer fluid circulating in a closed heat transfer fluid circuit.

[0035] The third exchanger is configured to operate as a refrigerant fluid evaporator.

[0036] The first branch of the bypass fluidly connects the second outlet of the liquid / vapor separation device to the second inlet of the compression device.

[0037] According to an example of implementation of the thermal conditioning system, the main loop includes a third expansion valve disposed between the second exchanger and the third exchanger.

[0038] The third expansion valve allows the second evaporator and the third evaporator to operate with different evaporation pressures, and therefore with different evaporation temperatures.

[0039] According to an example of implementation of the thermal conditioning system, the refrigerant circuit includes a second bypass branch arranged in parallel with the third exchanger.

[0040] The second bypass branch allows the refrigerant to bypass the third heat exchanger, thereby reducing the pressure drop in the portion of the circuit between the second heat exchanger and the inlet of the compression device. The cooling capacity of the second heat exchanger is thus improved when the third heat exchanger is thermally inactive.

[0041] The second branch branch connects a third connection point located on the main loop downstream of the second exchanger and upstream of the third exchanger to a fourth connection point located on the main loop downstream of the third exchanger and upstream of the first inlet of the compression device.

[0042] According to one embodiment of the thermal conditioning system, the refrigerant circuit includes a three-way valve arranged jointly on the main loop and on the second branch. The three-way valve is configured to selectively: - allow the refrigerant from the second heat exchanger to circulate in the third heat exchanger and prohibit refrigerant circulation in the second bypass branch, or - allow the refrigerant from the second exchanger to circulate in the second bypass branch and prohibit circulation of heat transfer fluid in the third exchanger.

[0043] The three-way valve allows the refrigerant to selectively bypass the third exchanger or circulate through the third exchanger.

[0044] Alternatively, the second branch branch includes a shut-off valve configured to selectively allow refrigerant circulation or block refrigerant circulation.

[0045] According to one embodiment of the thermal conditioning system, the compression device is a two-stage compression compressor, in which: - the first inlet of the compression device is a low-pressure refrigerant inlet, - the second inlet of the compression device is an inlet of refrigerant fluid at intermediate pressure, the intermediate pressure being greater than or equal to the low pressure.

[0046] According to another embodiment of the thermal conditioning system, the compression device comprises a first compressor having an inlet and an outlet, and a second compressor having an inlet and an outlet, in which: - a first refrigerant circulation channel connects the outlet of the first compressor to the inlet of the second compressor, and - a second refrigerant circulation channel connects the second inlet of the compression device to the first refrigerant circulation channel.

[0047] According to one embodiment of the thermal conditioning system, the liquid / vapor separation device is an expansion tank comprising: - an inlet configured to receive the refrigerant from the first expansion valve, - a first outlet configured to circulate refrigerant fluid in liquid state, the first outlet being fluidly connected to an inlet of the second expansion valve, - a second outlet configured to circulate refrigerant fluid in gaseous state, the second outlet being fluidly connected to the second inlet of the compression device.

[0048] According to another embodiment of the thermal conditioning system, the liquid / vapor separation device comprises: - a first refrigerant circulation channel connecting the inlet to the first outlet, - a second refrigerant circulation channel connecting a connection point located on the first channel to the second outlet, - a pressure-reducing device located on the second channel, - a heat exchanger configured to allow heat exchange between the refrigerant flowing in the first channel between the inlet and the first connection point and the refrigerant flowing in the second channel between the expansion device and the second outlet.

[0049] The heat exchanger is an internal exchanger allowing heat exchange between the refrigerant entering the liquid / vapor separation device and the refrigerant coming from the expansion device and circulating towards the second outlet.

[0050] According to one embodiment of the thermal conditioning system, the main loop of the refrigerant circuit includes an accumulation device located downstream of the first exchanger and upstream of the first expansion valve.

[0051] The accumulation device can be integrated into the first exchanger.

[0052] Alternatively, the main loop of the refrigerant circuit includes an accumulation device located downstream of the third exchanger and upstream of an inlet of the refrigerant compression device.

[0053] The invention also relates to a method of operating a thermal conditioning system as described above, in a first mode of operation in which: - an initial flow of refrigerant circulates through the compression device where it is subjected to high pressure, and then flows successively through the first heat exchanger where it releases heat, through the first expansion valve where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, and through the liquid / vapor separation device where it splits into: — a second flow of liquid refrigerant circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, then in the second heat exchanger where it evaporates, then in the third heat exchanger, and rejoins the first inlet of the compression device, — a third flow of gaseous refrigerant circulating in the first branch of the bypass and joining the second inlet of the compression device.

[0054] The invention also relates to a method of operating a thermal conditioning system as described above, in a second operating mode in which: - A first flow of refrigerant circulates in the compression device where it is under high pressure, and then flows successively through the first heat exchanger where it releases heat, and through the first expansion valve where it undergoes expansion and is reduced to a lower pressure intermediate pressure lower than high pressure, in the liquid / vapor separation device where it splits into: — a second flow of liquid refrigerant circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to a pressure lower than the intermediate pressure, in the second heat exchanger where it evaporates, in the third expansion valve where it undergoes expansion and passes to a low pressure, then in the third heat exchanger, and rejoins the first inlet of the compression device, — a third flow of gaseous refrigerant circulating in the first branch of the bypass and joining the second inlet of the compression device.

[0055] The invention further relates to a method of operating a thermal conditioning system as already described, in a third operating mode in which: - an initial flow of refrigerant circulates through the compression device where it is subjected to high pressure, and then flows successively through the first heat exchanger where it releases heat, through the first expansion valve where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, and through the liquid / vapor separation device where it splits into: — a second flow of liquid refrigerant circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, in the second heat exchanger where it evaporates, in the second bypass branch, and rejoins the first inlet of the compression device, — a third flow of gaseous refrigerant circulating in the first branch of the bypass and joining the second inlet of the compression device. Brief description of the drawings

[0056] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0057] [Fig-1] is a schematic view of a first example of a system of thermal conditioning according to the invention,

[0058] [Fig.2] is a schematic view of a second example of a thermal conditioning system according to the invention,

[0059] [Fig.3] is a schematic view of a third example of a thermal conditioning system according to the invention,

[0060] [Fig.4] is a schematic view of an embodiment of a thermal conditioning system according to [Fig.1],

[0061] [Fig. 5] is a schematic view of one embodiment of a system of thermal conditioning according to [Fig.2],

[0062] [Fig.6] is a schematic view of a first embodiment of a system of thermal conditioning according to [Fig.3],

[0063] [Fig.7] is a schematic view of a second embodiment of a system of thermal conditioning according to [Fig.3],

[0064] [Fig.8] is a schematic view of a third embodiment of a system of Thermal conditioning offered,

[0065] [Fig.9] is a schematic view of the thermal conditioning system of the [Fig.7], operating according to a first mode of operation,

[0066] [Fig. 10] is a schematic view of the thermal conditioning system of the [Fig. 5], operating according to a second mode of operation,

[0067] [Fig. 11] is a schematic view of the thermal conditioning system of the [Fig.7], operating according to a third mode of operation. Description of the implementation methods

[0068] To facilitate reading the figures, the various elements are not necessarily drawn to scale. In these figures, identical elements bear the same reference numerals. Certain 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 similar, but not identical, elements or parameters. This indexing does not imply any priority of one element or parameter over another, and the designations may be interchanged.

[0069] In the following description, the expression "a first element upstream of a second element" means that the first element is placed before the second element with respect 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 placed after the second element with respect to the direction of flow, or path, of the fluid in question. In the case of the refrigerant circuit, the term "a first element is 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. In other words, the refrigerant exits the compression device, possibly passes through one or more elements, then passes through the first element, then the second element, and then returns to the compression device, possibly after passing through other elements..

[0070] The expression "a second element is placed between a first element and a third element" means that the shortest path to go from the first element to the third element passes through the second element.

[0071] When it is specified that a subsystem includes a given element, this does not exclude the presence of other elements in that subsystem.

[0072] The thermal conditioning system 100, which will be described below, includes an electronic control unit, not shown in the various figures, which receives information from different sensors measuring, in particular, the characteristics of the refrigerant at various points in the circuit. The electronic control unit also receives instructions from the vehicle occupants, such as the desired temperature inside the passenger compartment. The electronic control unit can also receive instructions from other electronic subsystems, such as the electrical energy storage battery management system. The electronic control unit 60 implements control laws to operate the various actuators, in order to control the thermal conditioning system 100 and ensure compliance with the received instructions.

[0073] A compression device 7 allows a refrigerant to circulate in a refrigerant circulation circuit 10. The refrigerant circuit 10 forms a closed circuit in which the refrigerant can circulate. The refrigerant circuit 10 is leak-proof when it is in a nominal operating state, that is, without any fault or leak. Each connection point of circuit 10 allows the refrigerant to flow into one of the circuit sections that converge at that point. The refrigerant is distributed between these sections by opening or closing the shut-off valves, check valves, or expansion devices located on each section. In other words, each connection point redirects the refrigerant arriving at that 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 provide different operating modes, as will be described later.

[0074] The refrigerant used by the refrigerant circuit 10 is here a natural fluid, such as R290 or R744. A chemical refrigerant such as R1234yf, or 134a can also be used.

[0075] Each refrigerant expansion device, also called an expansion valve, can be an electronic expansion valve. In an electronic expansion valve, the passage cross-section allowing the refrigerant to pass through can be continuously adjusted between a closed position and a maximum open position. For this purpose, a The electronic control module of the expansion valve drives an electric motor that moves a movable shutter, controlling the cross-sectional area of ​​the refrigerant flow. Each expansion valve has exactly one refrigerant inlet and one refrigerant outlet.

[0076] The thermal conditioning system 100 may also include one or more heat transfer fluid circuits. The heat transfer fluid circuit(s) also form one or more closed and sealed circuits in which a heat transfer fluid can circulate.

[0077] The term "interior airflow Fi" refers to an airflow directed towards the passenger compartment of the 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 motor-fan unit, not shown, is located within the HVAC system to increase the flow rate of the interior airflow Fi if necessary.

[0078] The term "external airflow Fe" refers to an airflow that is not directed towards the vehicle's passenger compartment. In other words, this airflow Fe remains outside the vehicle's passenger compartment. A second motor-fan unit, also not shown, can be activated to increase the flow rate of the external airflow Fe if necessary. The airflow provided by both the first and second motor-fan units can be adjusted in real time according to heat exchange requirements, for example, by the electronic control unit 60 of the climate control system 100.

[0079] The term "first exchanger" is equivalent to the term "first heat exchanger". Similarly, the term "internal exchanger" is equivalent to the term "internal heat exchanger". The term "storage device" is equivalent to the term "refrigerant storage device".

[0080] Figure [1] shows a first example of a thermal conditioning system 100 as proposed. The 100 thermal conditioning system includes: - a refrigerant circuit 10 configured to circulate a refrigerant, - a compression device 7 comprising a first inlet 7A, a second inlet 7B and an outlet 7C, - a liquid / vapor separation device 5 comprising an inlet 5A, a first output 5B and a second output 5C. The refrigerant circuit 10 comprises a main refrigerant circulation loop A, which includes, successively according to the direction of refrigerant circulation: - the first input 7A of the compression device 7, - the 7C output of the compression device 7, - a first heat exchanger 1, - a first regulator 21, - the 5A input of the liquid / vapor separation device 5, - the first outlet 5B of the liquid / vapor separation device 5, - a second 22 regulator, - a second heat exchanger 2, - a third heat exchanger 3. The refrigerant circuit 10 includes a first branch B connecting the second outlet 5C of the liquid / vapor separation device 5 to the second inlet 7B of the compression device 7.

[0081] This refrigerant circuit architecture, with the first bypass branch B allowing a portion of the refrigerant to return to the intermediate-pressure compression device, and two heat exchangers 2, 3 arranged in series on the main loop A and capable of receiving low-pressure refrigerant, makes it possible to obtain good thermodynamic performance with a simple structure. The cooling capacity is thus increased, while also improving the coefficient of performance of the thermal conditioning system. Indeed, the compression ratio is reduced, improving the isentropic efficiency and therefore the power absorbed by the compression device.

[0082] In the illustrated example, the thermal conditioning system 100 is a thermal conditioning system for a motor vehicle.

[0083] The compression device 7 is configured to supply high-pressure refrigerant. The high-pressure refrigerant supplied by the compression device 7 circulates in the circuit 10.

[0084] The compression device 7 includes a refrigerant outlet 7C and two refrigerant inlets 7A, 7B. A first inlet 7A of the compression device 7 is configured to receive low-pressure refrigerant. The second inlet 7B of the compression device 7 is configured to receive intermediate pressure refrigerant. Intermediate pressure is a pressure greater than or equal to low pressure. High pressure is a pressure greater than intermediate pressure.

[0085] The compression device 7 is configured so that the refrigerant admitted through the first inlet 7A is discharged through the outlet 7C, and the refrigerant admitted through the second inlet 7B is also discharged through the outlet 7C.

[0086] The refrigerant fluid discharged from outlet 7C is in a state of high pressure. In other words, the compression device 7 comprises a first inlet 7A of low-pressure refrigerant, and a second inlet 7B of refrigerant at intermediate pressure. The compression device 7 increases the incoming refrigerant at low pressure to a high-pressure state and discharges it through outlet 7C. Similarly, the compression device 7 increases the incoming refrigerant at intermediate pressure to a high-pressure state and discharges it through outlet 7C.

[0087] The liquid / vapor separation device 5 is a vapor generation device. The liquid / vapor separation device 5 includes a refrigerant inlet 5A and two refrigerant outlets 5B, 5C.

[0088] The inlet 5A of the liquid / vapor separation device 5 is configured to receive refrigerant in a two-phase state. A two-phase state is understood to mean a mixture of liquid and vapor.

[0089] The first outlet 5B of the liquid / vapor separation device 5 is configured to supply refrigerant fluid in the liquid state. The second outlet 5C of the liquid / vapor separation device 5 is configured to supply refrigerant fluid in the gaseous state. The liquid / vapor separation device 5 is configured so that the refrigerant received by the inlet 5A is distributed between the first outlet 5B and the second outlet 5C.

[0090] The liquid / vapor separation device 5 allows the liquid phase and the gaseous phase of the admitted refrigerant fluid to be separated. The refrigerant admitted into the liquid / vapor separation device 5 is in a two-phase state. The refrigerant exiting the first outlet 5B is in the liquid phase, i.e., in a liquid state. The refrigerant exiting the second outlet 5C is in the vapor phase, i.e., in a gaseous state. A minimal fraction of vapor may remain in the liquid phase from the first outlet 5B of the liquid / vapor separation device 5. This fraction of vapor remaining in the so-called liquid phase is less than 5%. Similarly, a minimal fraction of liquid may remain in the vapor phase from the second outlet 5C of the liquid / vapor separation device 5. This fraction of liquid remaining in the so-called vapor phase is less than 5%.

[0091] The first heat exchanger 1 is configured to exchange heat with a first fluid FL

[0092] According to one embodiment, illustrated in particular in [Fig.4], the first fluid Fl is for example an interior airflow Fi to the passenger compartment of a motor vehicle. The first exchanger 1 is thus configured to exchange heat with an internal airflow Fi to the passenger compartment of a motor vehicle. The first exchanger 1 is thus thermally coupled with the internal airflow Fi, and this thermal coupling is then said to be direct. The first heat exchanger 1 is located in the vehicle's heating, ventilation and / or air conditioning system.

[0093] According to another embodiment, illustrated in particular in [Fig.6], the first heat exchanger 1 is configured to exchange heat with a heat transfer fluid circulating in a closed heat transfer fluid circuit 20, the heat transfer fluid circuit 20 comprising a heat exchanger IA configured to exchange heat with an interior airflow Fi to the vehicle's passenger compartment. The first fluid Fl is then a heat transfer fluid circulating in a closed circuit 20 of heat transfer fluid. In this case, the first exchanger 1 is thermally coupled with the internal airflow Fi in a so-called indirect way, since the thermal couple takes place via a heat transfer fluid. The IA heat exchanger is installed in the heating, ventilation and / or air conditioning system.

[0094] The heat transfer fluid is, for example, a mixture of water and glycol.

[0095] The first exchanger 1 is configured to operate as a refrigerant fluid condenser. The first heat exchanger 1 receives the high-pressure, high-temperature refrigerant fluid discharged by the compression device 7. The refrigerant fluid condenses in the first heat exchanger 1, and the heat of condensation is supplied to the first fluid FL

[0096] The main loop A of the refrigerant fluid circuit 10 includes an accumulation device 19 located downstream of the first heat exchanger 1 and upstream of the first expansion valve 21. Accumulation device 19 is a desiccant bottle. The accumulation device 19 can be integrated into the first exchanger 1 between a first part of heat exchange of the first exchanger 1 in which the refrigerant is condensed, and a second part of heat exchange of the first heat exchanger 1 in which the refrigerant in liquid state is subcooled.

[0097] The accumulation device 19 receives the refrigerant fluid from the first exchanger 1. The refrigerant fluid from the accumulation device 19 joins the first expansion valve 21.

[0098] The second heat exchanger 2 is configured to exchange heat with a second fluid F2.

[0099] According to the illustrated embodiments, the second exchanger 2 is thermally coupled with an element 25 of an electric traction chain of a motor vehicle. The second heat exchanger 2 allows the element 25 of the vehicle's electric powertrain to be cooled.

[0100] According to the illustrated embodiments, the second heat exchanger 2 is thermally coupled with the element 25 of the electric traction chain via a heat transfer fluid circulating in a heat transfer fluid circuit 30. The second fluid F2 is in this case a heat transfer fluid circulating in the heat transfer fluid circuit 30.

[0101] The second exchanger 2 is configured to operate as a refrigerant fluid evaporator. The second exchanger 2 receives the low-pressure refrigerant fluid from the second expansion valve 22.

[0102] According to one embodiment, element 25 of the vehicle's electric drive chain includes an electrical energy storage battery. In one alternative, or alternatively, element 25 of the vehicle's electric drivetrain includes a vehicle electric traction motor. Alternatively, or alternatively, element 25 of the vehicle's electric drivetrain may include an electronic control unit for the vehicle's electric traction motor.

[0103] The third heat exchanger 3 is configured to exchange heat with a third fluid F3.

[0104] According to one embodiment, illustrated in particular in [Fig.4], the third fluid F3 is for example an interior airflow Fi to the passenger compartment of a motor vehicle.

[0105] The third exchanger 3 is thus configured to exchange heat with an interior airflow Fi to the passenger compartment of a motor vehicle. The third exchanger 3 is thus thermally coupled with the internal airflow Fi, and this thermal coupling is then said to be direct. The third heat exchanger 3 is located in the vehicle's heating, ventilation and / or air conditioning system. The third heat exchanger 3 is arranged upstream of the first heat exchanger 1 in a direction of flow of the indoor airflow Fi. In other words, the indoor airflow first exchanges heat with the third heat exchanger 3 and then with the first heat exchanger 1.

[0106] According to another embodiment, illustrated in particular in [Fig. 6], the third heat exchanger 3 is configured to exchange heat with a heat transfer fluid circulating in a closed circuit 40 of heat transfer fluid, the circuit 40 of heat transfer fluid comprising a 3A heat exchanger configured to exchange heat with an internal airflow Fi to the vehicle's passenger compartment. The 3A exchanger is located in the vehicle's heating, ventilation and / or air conditioning system. The thermal coupling between the third heat exchanger 3 and the indoor airflow Fi is said to be indirect.

[0107] The third fluid F3 is in this case a heat transfer fluid circulating in a closed circuit 40 of heat transfer fluid.

[0108] The third exchanger 3 is configured to operate as a refrigerant fluid evaporator. In other words, the refrigerant can evaporate as it passes through the third exchanger 3, and then joins the first inlet 7A of the compression device 7.

[0109] The first branch branch B fluidly connects the second outlet 5C of the liquid / vapor separation device 5 to the second inlet 7B of the compression device 7.

[0110] The first branch branch B is arranged in parallel with the main loop A. The first branch branch B connects a first connection point 11 to a second connection point 12. The first connection point 11 coincides with the second outlet 5C of the liquid / vapor separation device 5. The second connection point 12 coincides with the second inlet 7B of the compression device 7.

[0111] In other words, the first branch of the bypass B allows the refrigerant to pass from the second outlet 5C of the liquid / vapor separation device 5 to the second inlet 7B of the compression device 7 without circulating through either the second expansion valve 22, or the second heat exchanger 2 and the third heat exchanger 3. The first branch of the bypass B circulates the refrigerant at intermediate pressure.

[0112] Figure 2 illustrates a second embodiment of the system Thermal conditioning 100 offered.

[0113] According to this second embodiment, illustrated in [Fig.2], the main loop A includes a third expansion valve 23 arranged between the second exchanger 2 and the third exchanger 3. The third regulator 23 is thus positioned downstream of the second exchanger 2 and upstream of the third exchanger 3.

[0114] The third expansion valve 23 thus allows the refrigerant fluid from the second exchanger 2 to be expanded before its admission into the third exchanger 3. The third expansion valve 23 allows the second evaporator 2 and the third evaporator 3 to operate with different evaporation pressures, and therefore with different evaporation temperatures.

[0115] Fig. 3 illustrates a third example of the implementation of the proposed thermal conditioning system.

[0116] According to this third embodiment, the refrigerant fluid circuit 10 includes a second branch C arranged in parallel with the third exchanger 3.

[0117] The second bypass branch C allows the refrigerant to bypass the third exchanger 3, which reduces the pressure drop in the portion of the circuit 10 between the outlet of the second exchanger 2 and the first inlet 7A of the compression device 7. Thanks to this reduction in pressure drop, the cooling capacity of the second exchanger 2 is improved when the third exchanger 3 is thermally inactive.

[0118] In other words, the refrigerant from the second exchanger 2 can return to the first inlet 7A of the compression device 7 without passing through the third exchanger 3.

[0119] The second branch C connects a third connection point 13 to a fourth connection point 14. The third connection point 13 is located on the main loop A downstream of the second exchanger 2 and upstream of the third exchanger 3. The fourth connection point 14 is located on the main loop A downstream of the third exchanger 3 and upstream of the first inlet 7A of the compression device 7.

[0120] According to this third embodiment of the thermal conditioning system 100, the refrigerant circuit 10 includes a three-way valve 31 arranged jointly on the main loop A and on the second branch C. The three-way valve 31 is configured to selectively: - allow the refrigerant from the second heat exchanger 2 to circulate in the third heat exchanger 3 and prohibit refrigerant circulation in the second branch of the bypass C, or - allow the refrigerant fluid from the second exchanger 2 to circulate in the second branch of bypass C and prohibit circulation of heat transfer fluid in the third exchanger 3.

[0121] The three-way valve 31 allows the refrigerant from the second heat exchanger 2 to either bypass the third heat exchanger 3, or to circulate in the third heat exchanger 3. In other words, the refrigerant from the second exchanger 2 can return to the first inlet 7A of the compression device 7 without passing through the third exchanger 3, by circulating in the second branch of bypass C.

[0122] According to an alternative embodiment not shown, the second branch of the bypass C may include a shut-off valve configured to selectively allow refrigerant circulation or block refrigerant circulation.

[0123] Figures 4 to 7 represent different embodiments of the thermal conditioning system examples shown in Figures 1 to 3. [Fig.4] is an embodiment of the example in [Fig.1], [Fig.5] is an embodiment of the example in [Fig.2]. [Fig.6] is a first embodiment of the example in [Fig.3], and [Fig.7] is a second embodiment of the example in [Fig.3].

[0124] Depending on the embodiment, the compression device 7 can be of different types.

[0125] According to an embodiment illustrated in [Fig.4], the compression device 7 comprises a first compressor 8 having an inlet 8a and an outlet 8b, and a second compressor 9 having an inlet 9a and an outlet 9b. In this compression device: - a first refrigerant circulation channel Cl connects the outlet 8b of the first compressor 8 to the inlet 9a of the second compressor 9, and - a second refrigerant circulation channel C2 connects the second inlet 7B of the compression device 7 to the first refrigerant circulation channel Cl.

[0126] The first inlet 7A of the compression device 7 corresponds to the inlet 8a of the first compressor 8. The second input 7B of the compression device 7 corresponds to the input of the second channel C2. Output 7C of compression device 7 corresponds to output 9b of the second compressor 9. The outlet 8a of the first compressor 8 is internal to the compression device 7. The connection point RI where the first channel Cl and the second channel C2 are fluidly connected is also internal to the compression device 7. By fluidly connected, we mean that fluid communication is established between the first channel Cl and the second channel C2.

[0127] The first compressor 8 draws in the refrigerant at the first inlet 8a and compresses it to a first pressure level called intermediate pressure. The refrigerant exits the first compressor 8b at intermediate pressure. The second compressor 9 draws in the intermediate-pressure refrigerant from the outlet 8b of the first compressor 8 or from the second inlet 7B of the compression device 7 compresses it to a second pressure level, known as high pressure. The refrigerant is discharged at outlet 9b of the second high-pressure compressor 9.

[0128] The first compressor 8 and the second compressor 9 are single-stage compressors and are arranged in series. The second channel C2 allows refrigerant to enter downstream of the first compressor 8 and upstream of the second compressor 9. Each compressor 8.9 can be an electric compressor, that is, its internal moving parts are driven by an electric motor.

[0129] According to an embodiment illustrated in [Fig.5], the compression device 7 is a two-stage compression compressor 7. In this two-stage compression compressor: - the first inlet 7A of the compression device 7 is a low-pressure refrigerant inlet, - the second inlet 7B of the compression device 7 is an inlet of intermediate pressure refrigerant fluid, the intermediate pressure being greater than or equal to the low pressure.

[0130] As before, the compressor 7 can be an electric compressor, that is, a compressor whose moving parts are driven by an electric motor. The compressor 7 has a first inlet 7A through which the low-pressure refrigerant is drawn in, a second inlet 7B through which the intermediate-pressure refrigerant is drawn in, and an outlet 7C through which the high-pressure refrigerant is discharged. The internal moving parts of the compressor 7 cause the refrigerant to pass from low pressure to high pressure, and from intermediate pressure to high pressure.

[0131] Depending on the embodiment, different types of liquid / vapor separation device 5 can also be used.

[0132] According to the embodiments illustrated in figures 4 and 7, the liquid / vapor separation device 5 is a pressure-reducing tank. The expansion tank includes: - a 5A input configured to receive the refrigerant from the first expansion valve 21, - a first outlet 5B configured to circulate refrigerant in liquid state, the first outlet 5B being fluidly connected to an inlet of the second expansion valve 22, - a second outlet 5C configured to circulate refrigerant fluid in a gaseous state, the second outlet 5C being fluidically connected to the second inlet 7B of the compression device 7.

[0133] According to the embodiments illustrated in Figures 5 and 6, the liquid / vapor separation device 5 comprises: - a first refrigerant circulation channel C3 connecting inlet 5A to first outlet 5B, - a second refrigerant circulation channel C4 connecting a connection point R2 located on the first channel C3 to the second outlet 5C, - an expansion device 24 located on the second channel C4, - a heat exchanger 6 configured to allow heat exchange between the refrigerant circulating in the first channel C3 between the inlet 5A and the first connection point R2 and the refrigerant circulating in the second channel C4 between the expansion device 23 and the second outlet 5C.

[0134] This liquid / vapor separation device 5 is called an “economizer”.

[0135] The heat exchanger 6 is an internal exchanger allowing heat exchange between the refrigerant entering the liquid / vapor separation device 5 and the refrigerant coming from the expansion device 24 and circulating towards the second outlet 5C.

[0136] The second channel C4 extends the first branch of derivation B. In other words, at the level of the first connection point R2, part of the refrigerant fluid is redirected to the second outlet 5C, and joins the second inlet 7B of the compression device 7 by circulating in the first branch of bypass B.

[0137] The [Fig.8] is a third embodiment of the proposed thermal conditioning system. In this embodiment, the first regulator 21 is not present. The refrigerant fluid from the storage device 19 reaches the inlet 5A of the economizer 5 without undergoing expansion or heat exchange.

[0138] The thermal conditioning system 100 comprises: - a refrigerant circuit 10 configured to circulate a refrigerant, - a compression device 7 comprising a first input 7A, a second input 7B and an output 7C, - a liquid / vapor separation device 5 comprising an inlet 5A, a first output 5B and a second output 5C. The refrigerant circuit 10 comprises a main refrigerant circulation loop A, which includes, successively according to the direction of refrigerant circulation: - the first input 7A of the compression device 7, - the 7C output of the compression device 7, - a first heat exchanger 1, - the 5A input of the liquid / vapor separation device 5, - the first outlet 5B of the liquid / vapor separation device 5, - a 21' regulator, - a second heat exchanger 2, - a third heat exchanger 3. The refrigerant fluid circuit 10 includes a first branch B connecting the second outlet 5C of the liquid / vapor separation device 5 to the second inlet 7B of the compression device 7.

[0139] The liquid / vapor separation device 5 is, in this third embodiment, of the "economizer" type, and comprises: - a first refrigerant circulation channel C3 connecting inlet 5A to first outlet 5B, - a second refrigerant circulation channel C4 connecting a connection point R2 located on the first channel C3 to the second outlet 5C, - an expansion device 24 located on the second channel C4, - a heat exchanger 6 configured to allow heat exchange between: — the refrigerant circulating in the first channel C3 between inlet 5A and the first connection point R2, and: — the refrigerant fluid circulating in the second channel C4 between the expansion device 23 and the second outlet 5C.

[0140] In [Fig. 8], the compression device 7 comprises two separate compressors. The refrigerant circuit 10 includes a second bypass branch C. The thermal coupling between the first heat exchanger 1 and the internal airflow Fi is indirect. Similarly, the thermal coupling between the third heat exchanger 3 and the internal airflow Fi is indirect.

[0141] According to unrepresented variants of this third embodiment: The compression device 7 may include a single two-stage compression compressor. The thermal coupling between the first exchanger 1 and the indoor airflow Fi can be direct, and the same is true for the third exchanger 3. The second branch of derivation C may not be present. These variants can be combined independently of each other.

[0142] The thermal conditioning system 100 can operate in several operating modes. Figures 9 to 11 illustrate different modes of operation.

[0143] In these figures, the portions of the refrigerant circuit 10 in which a flow of refrigerant circulates are shown in thick solid lines, while the portions in which the refrigerant does not circulate are shown in thin dashed lines. Different arrows indicate the direction of refrigerant flow in the different sections of circuit 10.

[0144] Fig.9 schematically illustrates a method of operation of a thermal conditioning system 100 according to the embodiment illustrated in Fig.7.

[0145] In this first mode of operation: - a first flow Q1 of refrigerant circulates in the compression device 7 where it passes through high pressure, and circulates successively in the first heat exchanger 1 where it releases heat, in the first expansion valve 21 where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the liquid / vapor separation device 5 where it divides into: — a second flow Q2 of liquid refrigerant circulating in the main loop A, successively in the second expansion valve 22 where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, then in the second heat exchanger 2 where it evaporates, then in the third heat exchanger 3, and joins the first inlet 7A of the compression device 7, — a third flow Q3 of gaseous refrigerant circulating in the first branch of bypass B and joining the second inlet 7B of the compression device 7.

[0146] Part of the refrigerant fluid from the first exchanger 1 returns to the intermediate pressure compression device 7, without passing through the second expansion valve 22 and the exchangers located downstream. The evaporation pressure of the refrigerant is the same in the second exchanger 2 and in the third exchanger 3.

[0147] The value of the so-called high pressure is for example between 15 bar and 33 bar. The value of the pressure called intermediate pressure is, for example, between 5 bar and 15 bar. The value of the so-called low pressure is, for example, between 2 bar and 7 bar.

[0148] This mode of operation is illustrated with a configuration in which the compression device 7 comprises a two-stage compressor, in which the first heat exchanger 1 and the third heat exchanger 3 exchange heat with the internal airflow Fi via a heat transfer fluid, and in which the liquid / vapor separation device is an expansion tank. The same mode of operation can be applied to a configuration with two single-stage compressors, or including an economizer, or in which the first heat exchanger 1 and the third heat exchanger 3 exchange heat directly with the internal airflow Fi.

[0149] Fig. 10 schematically illustrates a method of operation of a thermal conditioning system 100 according to the embodiment illustrated in Fig. 5.

[0150] In this second mode of operation: - a first flow Q1 of refrigerant circulates in the compression device 7 where it passes through high pressure, and circulates successively in the first heat exchanger 1 where it releases heat, in the first expansion valve 21 where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the liquid / vapor separation device 5 where it divides into: — a second flow Q2 of liquid refrigerant circulating in the main loop A, successively in the second expansion valve 22 where it undergoes expansion and passes to a pressure lower than the intermediate pressure, in the second heat exchanger 2 where it evaporates, in the third expansion valve 23 where it undergoes expansion and passes to a low pressure, then in the third heat exchanger 3, and joins the first inlet 7A of the compression device 7, — a third flow Q3 of gaseous refrigerant circulating in the first branch of bypass B and joining the second inlet 7B of the compression device 7.

[0151] Part of the refrigerant fluid from the first exchanger 1 returns to the intermediate pressure compression device 7, and does not pass through the second expansion valve 22 and the exchangers 2, 3 located downstream. The evaporation pressure of the refrigerant is higher in the second heat exchanger 2 than in the third heat exchanger 3, since an expansion is carried out between the outlet of the second heat exchanger 2 and the inlet of the third heat exchanger 3. The evaporation temperature is therefore lower in the third heat exchanger 3 than in the second heat exchanger 2, which allows the cooling to be better adapted to the needs of the fluid with which each heat exchanger is thermally coupled.

[0152] This mode of operation is illustrated with a configuration in which the compression device 7 comprises a two-stage compressor, the first heat exchanger 1 and the third heat exchanger 3 exchange heat with the internal airflow Fi, and the liquid / vapor separation device is an economizer. The same mode of operation can be applied to a configuration with two single-stage compressors, or comprising an expansion tank, or in which the first heat exchanger 1 and the third heat exchanger 3 exchange heat with the internal airflow Fi via a heat transfer fluid.

[0153] Fig. 11 schematically illustrates a method of operation of a thermal conditioning system 100 according to the embodiment illustrated in Fig. 6.

[0154] In this third mode of operation: - a first flow Q1 of refrigerant circulates in the compression device 7 where it passes through high pressure, and circulates successively in the first exchanger 1 where It releases heat in the first expansion valve 21 where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the liquid / vapor separation device 5 where it splits into: — a second flow Q2 of liquid refrigerant circulating in the main loop A, successively in the second expansion valve 22 where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, in the second heat exchanger 2 where it evaporates, in the second bypass branch C, and joins the first inlet 7A of the compression device 7, — a third flow Q3 of gaseous refrigerant circulating in the first branch of bypass B and joining the second inlet 7B of the compression device 7.

[0155] Part of the refrigerant fluid from the first exchanger 1 returns to the intermediate pressure compression device 7. Part of the refrigerant fluid is expanded to a low pressure and evaporates in the second exchanger 2, then returns to the first inlet of the compression device 7 by bypassing the third exchanger 3. The three-way valve 31 directs the refrigerant from the second exchanger 2 to the second branch of the bypass C, and prohibits the circulation of refrigerant to the third exchanger 3. The third exchanger 3 is therefore not traversed by refrigerant fluid, and does not contribute to the pressure drop of the circuit. The evaporation temperature in the second exchanger 2 is thus lowered compared to a thermal conditioning system in which the second exchanger 2 and the third exchanger 3 are always connected in series.

[0156] This mode of operation is illustrated for a thermal conditioning system configuration in which the compression device 7 comprises two single-stage compressors, where the first heat exchanger 1 and the third heat exchanger 3 exchange heat with a heat transfer fluid, which itself exchanges heat with the indoor airflow Fi, and where the liquid / vapor separation device is an economizer. The same mode of operation can be applied to a configuration with a two-stage compressor, or including an expansion tank, or in which the first heat exchanger 1 and the third heat exchanger 3 exchange heat with the indoor airflow Fi.

[0157] According to an unillustrated variant, the main loop A of the refrigerant circuit 10 includes an accumulation device disposed downstream of the third exchanger 3 and upstream of an inlet 7A of the refrigerant compression device 7. The accumulation device is an accumulator.

Claims

Demands

1. Thermal conditioning system (100), comprising: - a refrigerant circuit (10) configured to circulate a refrigerant, - a compression device (7) having a first inlet (7A), a second inlet (7B) and an outlet (7C), - a liquid / vapor separation device (5) having an inlet (5A), a first outlet (5B) and a second outlet (5C), in which the refrigerant circuit (10) has a main refrigerant circulation loop (A) comprising successively, in a direction of refrigerant circulation: - the first inlet (7A) of the compression device (7), - the outlet (7C) of the compression device (7), - a first heat exchanger (1), - a first expansion valve (21), - the inlet (5A) of the liquid / vapor separation device (5), - the first outlet (5B) of the liquid / vapor separation device (5), - a second expansion valve (22),- a second heat exchanger (2), - a third heat exchanger (3), and wherein the refrigerant circuit (10) comprises a first branch (B) connecting the second outlet (5C) of the liquid / vapor separation device (5) to the second inlet (7B) of the compression device (7).

2. Thermal conditioning system (100) according to claim 1, wherein the main loop (A) includes a third expansion valve (23) disposed between the second exchanger (2) and the third exchanger (3).

3. Thermal conditioning system (100) according to claim 1, wherein the refrigerant circuit (10) includes a second bypass branch (C) arranged in parallel with the third exchanger (3).

4. Thermal conditioning system (100) according to the preceding claim, in which the refrigerant circuit (10) includes a three-way valve (31) disposed jointly on the main loop (A) and on the second bypass branch (C), The three-way valve (31) is configured to selectively: - allow the refrigerant from the second exchanger (2) to flow into the third exchanger (3) and prohibit refrigerant flow into the second bypass branch (C), or - allow the refrigerant from the second exchanger (2) to flow into the second bypass branch (C) and prohibit heat transfer fluid flow into the third exchanger (3).

5. Thermal conditioning system (100) according to any one of claims 1 to 4, wherein the compression device (7) is a two-stage compression compressor (7), wherein: - the first inlet (7A) of the compression device (7) is a low-pressure refrigerant inlet, - the second inlet (7B) of the compression device (7) is an intermediate-pressure refrigerant inlet, the intermediate pressure being greater than or equal to the low pressure.

6. Thermal conditioning system (100) according to any one of claims 1 to 4, wherein the compression device (7) comprises a first compressor (8) having an inlet (8a) and an outlet (8b), and a second compressor (9) having an inlet (9a) and an outlet (9b), in which: - a first refrigerant (Cl) circulation channel (Cl) connects the outlet (8b) of the first compressor (8) to the inlet (9a) of the second compressor (9), and - a second refrigerant circulation channel (C2) connects the second inlet (7B) of the compression device (7) to the first refrigerant circulation channel (Cl).

7. Thermal conditioning system (100) according to any one of claims 1 to 6, wherein the liquid / vapor separation device (5) is an expansion tank comprising: - an inlet (5A) configured to receive the refrigerant from the first expansion valve (21), - a first outlet (5B) configured to circulate refrigerant in the liquid state, the first outlet (5B) being fluidly connected to an inlet of the second expansion valve (22), - a second outlet (5C) configured to circulate refrigerant in the gaseous state, the second outlet (5C) being connected fluidly to the second inlet (7B) of the compression device (7).

8. Thermal conditioning system (100) according to any one of claims 1 to 6, wherein the liquid / vapor separation device (5) comprises: - a first refrigerant circulation channel (C3) connecting the inlet (5A) to the first outlet (5B), - a second refrigerant circulation channel (C4) connecting a connection point (R2) disposed on the first channel (C3) to the second outlet (5C), - an expansion device (24) disposed on the second channel (C4), - a heat exchanger (6) configured to allow heat exchange between the refrigerant circulating in the first channel (C3) between the inlet (5A) and the first connection point (R2) and the refrigerant circulating in the second channel (C4) between the expansion device (23) and the second outlet (5C).

9. A method of operating a thermal conditioning system (100) according to any one of claims 1 to 8, in a first mode of operation in which: - a first flow (Q1) of refrigerant circulates in the compression device (7) where it passes through a high pressure, and circulates successively in the first heat exchanger (1) where it releases heat, in the first expansion valve (21) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the liquid / vapor separation device (5) where it splits into: — a second flow (Q2) of liquid refrigerant circulating in the main loop (A), successively in the second expansion valve (22) where it undergoes expansion and passes through a low pressure lower than the intermediate pressure, then in the second heat exchanger (2) where it evaporates, then in the third heat exchanger (3), and rejoins the first inlet (7A) of the compression device (7),— a third flow (Q3) of gaseous refrigerant circulating in the first bypass branch (B) and joining the second inlet (7B) of the compression device (7).

10. A method of operating a thermal conditioning system (100) according to any one of claims 1 to 8 in combination with claim 2, in a second operating mode in which: - a first flow (Q1) of refrigerant circulates in the compression device (7) where it passes through high pressure, and circulates successively in the first heat exchanger (1) where it releases heat, in the first expansion valve (21) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the liquid / vapor separation device (5) where it divides into: — a second flow (Q2) of liquid refrigerant circulating in the main loop (A), successively in the second expansion valve (22) where it undergoes expansion and passes through a pressure lower than the intermediate pressure, in the second heat exchanger (2) where it evaporates, in the third expansion valve (23) where it undergoes expansion and passes through a low pressure, then in the third heat exchanger (3), and joins the first inlet (7A) of the compression device (7),— a third flow (Q3) of gaseous refrigerant circulating in the first bypass branch (B) and joining the second inlet (7B) of the compression device (7).

11. A method of operating a thermal conditioning system (100) according to any one of claims 1 to 8 in combination with claim 3, in a third mode of operation in which: - a first flow (Q1) of refrigerant circulates in the compression device (7) where it passes through a high pressure, and circulates successively in the first heat exchanger (1) where it releases heat, in the first expansion valve (21) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the liquid / vapor separation device (5) where it splits into: - a second flow (Q2) of liquid refrigerant circulating in the main loop (A), successively in the second expansion valve (22) where it undergoes expansion and passes through a low pressure lower than the intermediate pressure, in the second heat exchanger (2) where it evaporates, in the second bypass branch (C),and joins the first inlet (7A) of the compression device (7), — a third flow (Q3) of gaseous refrigerant circulating in the first bypass branch (B) and joining the second inlet (7B) of the compression device (7).

Images