Thermal conditioning system

Abstract

The invention relates to a thermal conditioning system (100) for a motor vehicle, comprising a refrigerant circuit (10) having: - a main loop (A) comprising successively: - a compressor (7), - a first heat exchanger (1) thermally coupled with a first interior airflow (Fi1) to a vehicle passenger compartment, - a first expansion valve (31), - a second expansion valve (32), - a second heat exchanger (2) configured thermally coupled with an exterior airflow (Fe) to the vehicle passenger compartment, - a first branch (B) comprising successively a third expansion valve (33) and a third heat exchanger (3), - a second branch (C) comprising successively a fourth expansion valve (34) and a fourth heat exchanger (4) thermally coupled with the first interior airflow (Fi1). Abstract figure: Figure 2

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. Previous technique

[0002] Chemical refrigerants generally have a high global warming potential (GWP), which is a disadvantage. Carbon dioxide, which by definition has a global warming potential of one, can be used as a refrigerant. To optimize energy efficiency, it is useful to have multiple operating modes available in order to make the best use of the various available heat sources.

[0003] In one of these operating modes, heat losses related to electric propulsion can contribute to heating the vehicle's passenger compartment. Precise control of the energy recovered from heat losses is generally difficult, particularly when these heat losses are small. Furthermore, performance requirements in terms of passenger thermal comfort are increasing. In particular, it is desirable to reduce the time required to heat the vehicle's passenger compartment.

[0004] There is therefore a need for a thermal conditioning system to improve the thermal comfort of passengers, offering many operating modes and allowing simplified control of these different operating modes. Summary

[0005] To this end, a thermal conditioning system for motor vehicles is proposed, 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 thermally coupled with a first flow of air inside a vehicle passenger compartment, — a first regulator, — a second regulator, — a second heat exchanger configured to be thermally coupled with an outside airflow to the vehicle's passenger compartment, — a refrigerant fluid accumulation device, - a first branch connecting a first connection point located on the main loop downstream of the first expansion valve and upstream of the second expansion valve to a second connection point located on the main loop downstream of the second heat exchanger and upstream of the storage device, the first branch successively comprising a third expansion valve and a third heat exchanger, - a second branch connecting a third connection point located on the main loop downstream of the first regulator and upstream of the first connection point to a fourth connection point located on the main loop downstream of the second connection point and upstream of the accumulation device, the second branch of the bypass comprising successively a fourth expansion valve and a fourth heat exchanger thermally coupled with the first flow of indoor air.

[0006] The features listed in the following paragraphs can be implemented independently of each other or in any technically possible combination:

[0007] The fourth connection point can be confused with the second connection point.

[0008] The first exchanger is configured to operate as a refrigerant fluid condenser.

[0009] The first heat exchanger allows the vehicle's passenger compartment to be heated.

[0010] According to one embodiment, the first heat exchanger is configured to exchange heat with the first airflow inside the vehicle's passenger compartment.

[0011] 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 the first airflow inside the vehicle's passenger compartment.

[0012] The second exchanger is configured to operate selectively as a refrigerant condenser or as a refrigerant evaporator.

[0013] The second exchanger allows heat to be selectively dissipated into the outside airflow, or heat to be received from the outside airflow.

[0014] According to one embodiment, the second exchanger is configured to exchange heat with the outside airflow to the vehicle's passenger compartment.

[0015] According to one embodiment, the second 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 the outside airflow to the vehicle's passenger compartment.

[0016] The third heat exchanger is configured to operate as a refrigerant fluid evaporator.

[0017] The fourth heat exchanger is configured to operate as a refrigerant fluid evaporator.

[0018] The fourth heat exchanger can cool the first flow of air inside the passenger compartment, so as to cool a first part of the passenger compartment, for example the front part.

[0019] The fourth exchanger is arranged upstream of the first exchanger according to a flow direction of the first internal airflow.

[0020] According to one embodiment of the thermal conditioning system, the third heat exchanger is thermally coupled with an element of an electric traction chain of a motor vehicle.

[0021] The third heat exchanger allows the element of the vehicle's electric powertrain to be cooled, or the heat losses of this powertrain element to be recovered.

[0022] According to one embodiment, the element of the vehicle's electric drive chain includes an electrical energy storage battery.

[0023] Alternatively or in addition, the element of the vehicle's electric drive chain includes an electric vehicle traction motor.

[0024] Alternatively or in addition, the element of the vehicle's electric traction chain includes an electronic control unit for the vehicle's electric traction motor.

[0025] According to one embodiment, the third 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.

[0026] According to one embodiment of the thermal conditioning system, the refrigerant circuit includes a third branch connecting a fifth connection point located on the main loop downstream of the first expansion valve and upstream of the first connection point to a sixth connection point located on the second branch downstream of the fourth exchanger and upstream of the fourth connection point, the third branch comprising successively a fifth expansion valve and a fifth heat exchanger configured to exchange heat with a second indoor airflow.

[0027] The fifth heat exchanger is configured to operate as a refrigerant fluid evaporator.

[0028] The fifth heat exchanger allows the second flow of air inside the passenger compartment to be cooled, so as to particularly cool a second area of ​​the passenger compartment.

[0029] According to one embodiment, the third branch of the bypass includes a sixth expansion valve disposed downstream of the fifth heat exchanger. In other words, the third branch of the bypass successively comprises a fifth expansion valve, a fifth heat exchanger configured to exchange heat with a second stream of indoor air, and a sixth expansion valve.

[0030] The sixth expansion valve allows the third and fifth exchangers to operate at different evaporation pressures.

[0031] The fifth connection point can be confused with the third connection point.

[0032] According to one embodiment of the thermal conditioning system, the refrigerant circuit includes a fourth branch connecting a seventh connection point located on the main loop downstream of a compressor outlet and upstream of the first exchanger to an eighth connection point located on the main loop downstream of the second heat exchanger and upstream of the storage device, the fourth branch including a seventh expansion valve.

[0033] The fourth branch of the bypass allows the refrigerant fluid from the compressor to be sent to the second heat exchanger, in order to cool it, in particular for operating modes involving cooling of the vehicle's passenger compartment.

[0034] According to an embodiment of the thermal conditioning system, in which the refrigerant circuit includes a fifth branch connecting a ninth connection point located on the second branch downstream of the fourth exchanger and upstream of the fourth connection point to a tenth connection point located on the first branch downstream of the first connection point and upstream of the first expansion valve.

[0035] The fifth bypass branch allows high-pressure or intermediate-pressure refrigerant from the fourth heat exchanger to be redirected to the second expansion valve and the second heat exchanger. The fourth heat exchanger can thus operate as a refrigerant condenser and can heat the first interior airflow. The first interior airflow is therefore heated successively by the fourth and first heat exchangers, which accelerates the heating of the passenger compartment.

[0036] The ninth connection point can be confused with the sixth connection point. The tenth connection point can be confused with the first connection point.

[0037] In the embodiment where the refrigerant circuit includes the fifth branch, the second branch includes a sixth expansion valve disposed downstream of the ninth connection point. In other words, the sixth regulator is positioned in this case between the fourth connection point and the ninth connection point.

[0038] According to one embodiment of the thermal conditioning system, the main loop of the refrigerant circuit includes an internal exchanger configured to allow heat exchange between the refrigerant circulating between the first connection point and the second expansion valve and the refrigerant downstream of the accumulation device and upstream of a compressor inlet.

[0039] The internal exchanger makes it possible to increase the enthalpy variation of the refrigerant during the thermodynamic cycle, and therefore to increase the thermal power that the thermal conditioning system can provide.

[0040] The internal heat exchanger includes a first heat exchange section arranged on the main loop between the first connection point and the second expansion valve. The internal heat exchanger has a second heat exchange section located on the main loop downstream of the accumulator and upstream of the compressor inlet.

[0041] The internal heat exchanger is configured to allow heat exchange between the refrigerant in the first heat exchange section and the refrigerant in the second heat exchange section.

[0042] The main loop includes a first shut-off valve located upstream of the first exchanger. The first shut-off valve is located downstream of the seventh connection point.

[0043] The main loop includes a second shut-off valve located downstream of the second heat exchanger and upstream of the second connection point. The second shut-off valve can be positioned between the eighth connection point and the second connection point.

[0044] The first shut-off valve is an electrically operated valve. The second shut-off valve is an electrically operated valve.

[0045] The first shut-off valve is a two-way valve. Similarly, the second shut-off valve is a two-way valve.

[0046] The refrigerant circuit includes a first one-way valve disposed on the second branch of the branch, the first one-way valve being configured to allow refrigerant flow through the first one-way valve of the fourth exchanger to the sixth connection point, and being configured to prohibit refrigerant flow through the first one-way valve of the sixth connection point to the fourth exchanger.

[0047] The main loop may include a third shut-off valve disposed between the fifth connection point and the first connection point.

[0048] The third shut-off valve is a two-way, electrically operated valve.

[0049] The refrigerant circuit may include a second one-way valve disposed on the third branch of the bypass, the second one-way valve being configured to permit refrigerant flow through the second one-way valve from the fifth exchanger to the sixth connection point, and being configured to prohibit refrigerant flow through the second one-way valve from the sixth connection point to the fifth exchanger.

[0050] The refrigerant circuit may include a third one-way valve disposed on the fifth branch of the branch, the third one-way valve being configured to permit refrigerant flow through the third one-way valve from the ninth connection point to the tenth connection point, and being configured to prohibit refrigerant flow through the third one-way valve from the tenth connection point to the ninth connection point.

[0051] Each of the one-way valves is a check valve.

[0052] Alternatively, each of the one-way valves can be an electrically operated valve.

[0053] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called 'heat pump with cabin air extraction' mode in which: - an initial flow of refrigerant circulates in the compressor where it passes under high pressure, and circulates in the main loop, successively in the first heat exchanger where it releases heat, in the first expansion valve, and divides into: — a second flow circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to a low pressure lower than the high pressure, in the second exchanger where it receives heat, — a third flow circulating in the third branch of the bypass, successively in the fifth pressure regulator where it undergoes expansion and passes to an intermediate pressure lower than the high pressure and higher than the low pressure, in the fifth heat exchanger where it receives heat, in the sixth pressure regulator where it undergoes expansion and passes to a low pressure, and joins the refrigerant flow from the second exchanger, the total flow formed circulates in the accumulation device and returns to the compressor.

[0054] The refrigerant fluid can circulate in the first expansion valve without undergoing expansion.

[0055] The refrigerant fluid can undergo expansion in the first expansion valve and pass to an intermediate pressure lower than the high pressure and higher than the low pressure.

[0056] In this operating mode: - The refrigerant flow rate in the first branch of the bypass is zero. - The refrigerant flow rate in the second bypass branch is zero. - The refrigerant flow rate in the fourth branch of the bypass is zero.

[0057] The first exchanger heats the first flow of indoor air. The second exchanger evaporates the refrigerant, with the heat of vaporization being supplied by the outside airflow. The fifth exchanger also evaporates the refrigerant, with the heat of vaporization being supplied by the second internal airflow. The fourth exchanger is thermally inactive, meaning there is no heat exchange between the refrigerant and the first indoor airflow.

[0058] In this mode of operation, the passenger compartment is heated at the level of the first exchanger, from the heat taken from the outside airflow, from the heat taken from the second inside airflow, and from the energy supplied to the refrigerant by the compressor.

[0059] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called 'heat pump with energy recovery' mode in which: - a first flow of refrigerant circulates in the compressor where it passes under high pressure, and circulates in the main loop, successively in the first heat exchanger where it releases heat, in the first expansion valve where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, and divides into: — a second flow circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to a low pressure lower than the high pressure, in the second heat exchanger where it receives heat, and — a third flow circulating in the first branch of the bypass, successively in the third expansion valve where it undergoes expansion and passes to low pressure, in the third exchanger where it receives heat, and joins the flow of refrigerant fluid coming from the second exchanger, the total flow formed circulates in the accumulation device and returns to the compressor.

[0060] In this operating mode, the second flow rate may be greater than the third flow rate.

[0061] In this operating mode: - The refrigerant flow rate in the second bypass branch is zero. - The refrigerant flow rate in the third branch of the bypass is zero. - The refrigerant flow rate in the fourth branch of the bypass is zero.

[0062] In this mode of operation, the passenger compartment is heated at the level of the first exchanger, from the heat taken from the outside air flow, from the recovery of the thermal losses of the element, and from the energy supplied to the refrigerant by the compressor.

[0063] The refrigerant used to recover heat losses from the element undergoes two successive expansions: the first as it passes through the first expansion valve and the second as it passes through the third expansion valve. For the same total expansion level, the opening of the third expansion valve is thus greater than the opening that would be obtained if the third expansion valve alone performed an expansion from high pressure to low pressure. The third expansion valve can therefore operate within an opening range more favorable to precise control of the flow rate through it. Indeed, this opening range is far from the minimum opening of the third expansion valve.

[0064] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called 'heat pump with energy recovery and cabin air extraction' mode in which: - a first flow of refrigerant circulates in the compressor where it passes through high pressure, and circulates in the main loop, successively in the first exchanger where it releases heat, in the first expansion valve, and divides into: — a second flow circulating in the main loop, — a third flow circulating in the third branch of the bypass, successively in the fifth pressure regulator where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the fifth heat exchanger where it receives heat, in the sixth pressure regulator where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, - the second flow rate is divided into: — a fourth flow circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to a low pressure lower than the high pressure, in the second heat exchanger where it receives heat, and — a fifth flow circulating in the first branch of the bypass, successively in the third expansion valve where it undergoes expansion and passes to low pressure, in the third exchanger where it receives heat, and joins the refrigerant flow from the sixth expansion valve and the refrigerant flow from the second exchanger, The total flow formed circulates through the accumulation device and returns to the compressor.

[0065] The refrigerant can flow through the first expansion valve without undergoing expansion.

[0066] The refrigerant can undergo expansion in the first expansion valve and pass through an intermediate pressure lower than the high pressure and higher than the low pressure.

[0067] In this operating mode: - The refrigerant flow rate in the second bypass branch is zero. - The refrigerant flow rate in the fourth branch of the bypass is zero.

[0068] In this mode of operation, the passenger compartment is heated at the level of the first exchanger, from the heat taken from the outside airflow, the heat taken from the second inside airflow, the heat losses of the traction chain element and the energy supplied to the refrigerant by the compressor.

[0069] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called 'heat pump with accelerated heating of the passenger compartment' mode4 in which: - a first flow of refrigerant circulates in the compressor where it passes through high pressure, and circulates in the main loop, successively in the first heat exchanger where it releases heat, in the first expansion valve, then circulates in the second bypass branch, successively in the fourth expansion valve where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the fourth heat exchanger where it releases heat, then it flows through the fifth branch and rejoins the main loop, then it circulates successively through the second expansion valve where it undergoes expansion and passes to a lower pressure than the high pressure, through the second exchanger where it receives heat, through the accumulation device and returns to the compressor.

[0070] In this operating mode: - The third shut-off valve is in the closed position. - The refrigerant flow rate in the portion of the main loop between the third connection point and the first connection point is zero. - The refrigerant flow rate in the third branch of the bypass is zero. - The refrigerant flow rate in the portion of the first branch of the bypass between the tenth connection point and the fourth connection point is zero. - The refrigerant flow rate in the fourth branch of the bypass is zero.

[0071] In this mode of operation, the first interior airflow of the passenger compartment is heated at the level of the first exchanger and the fourth exchanger, from the heat taken from the outside airflow and the energy supplied to the refrigerant by the compressor.

[0072] The invention also relates to a method of operating a thermal conditioning system as already described, in a mode called 'heat pump with passenger compartment preheating and passenger compartment air extraction'4 in which: - a first flow of refrigerant circulates in the compressor where it passes through a high pressure, and circulates in the main loop, successively in the first exchanger where it releases heat, in the first expansion valve, and divides into: — a second flow circulating in the second bypass branch, successively in the fourth expansion valve where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the fourth exchanger where it releases heat, and — a third flow circulating in the third bypass branch, successively in the fifth expansion valve where it undergoes expansion and passes through an intermediate pressure, in the fifth exchanger where it receives heat,and joins the refrigerant flow from the fourth heat exchanger; the total flow formed circulates in the fifth bypass branch and joins the main loop, then circulates successively through the second expansion valve where it undergoes expansion and passes through a low pressure lower than the high pressure, through the second heat exchanger where it receives heat, through the accumulation device and returns to the compressor.

[0073] This mode of operation differs from the previous one in that the refrigerant fluid from the first expansion valve circulates in parallel in the fourth exchanger and in the fifth exchanger before being expanded by the second expansion valve.

[0074] The intermediate pressure refrigerant circulating in the fourth exchanger exchanges heat with the first indoor airflow which has not been heated by another heat exchanger, and condenses, giving up heat to the first indoor airflow. The intermediate pressure refrigerant circulating in the fifth exchanger exchanges heat with the second indoor airflow, which is at a higher temperature than the first indoor airflow, and evaporates, taking heat from the second indoor airflow.

[0075] In this mode of operation, the first interior airflow of the passenger compartment is heated at the level of the first exchanger and the fourth exchanger, from the heat taken from the outside airflow, the second interior airflow and the energy supplied to the refrigerant by the compressor.

[0076] The invention also relates to a method of operating a thermal conditioning system as already described, in a mode known as 'heat pump with energy recovery and extraction of passenger air' in which: - a first flow of refrigerant circulates in the compressor where it passes through high pressure, and circulates in the main loop, successively in the first exchanger where it releases heat, in the first expansion valve, and divides into: - a second flow circulating in the main loop, - a third flow circulating in the third bypass branch, successively in the fifth expansion valve where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the fifth exchanger where it receives heat, in the second bypass branch, in the sixth expansion valve where it undergoes expansion and passes through a low pressure lower than the intermediate pressure,- the second flow rate is divided into: , — a fourth flow circulating in the main loop, successively in the second expansion valve where it undergoes expansion and passes to low pressure, in the second heat exchanger where it receives heat, and — a fifth flow circulating in the first branch of the bypass, successively in the third expansion valve where it undergoes expansion and passes to low pressure, in the third exchanger where it receives heat, and joins the flow of refrigerant from the sixth expansion valve and the flow of refrigerant from the second exchanger, the total flow formed circulates in the accumulation device and returns to the compressor.

[0077] In this operating mode: - the third shut-off valve is in the open position. - The refrigerant flow rate in the fifth branch of the bypass is zero. - The refrigerant flow rate in the fourth branch of the bypass is zero.

[0078] In this mode of operation, the first interior airflow to the passenger compartment is heated at the level of the first exchanger, from the heat taken from the outside airflow, the heat taken from the second interior airflow, the heat losses of the traction chain element and the energy supplied to the refrigerant by the compressor.

[0079] The high-pressure refrigerant fluid heats the first internal airflow at the level of the first exchanger. The intermediate-pressure refrigerant also heats the first interior airflow at the fourth heat exchanger. The combined heating at these two heat exchangers allows for accelerated heating of the passenger compartment. The second exchanger evaporates the refrigerant, with the heat of vaporization being supplied by the outside airflow. The third exchanger is thermally inactive. The fifth heat exchanger is thermally inactive. Brief description of the drawings

[0080] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0081] [Fig-1] is a schematic view of a thermal conditioning system according to a first embodiment of the invention,

[0082] [Fig.2] is a schematic view of a thermal conditioning system according to a second embodiment of the invention,

[0083] [Fig.3] is a schematic view of a thermal conditioning system according to a variant of the second embodiment,

[0084] [Fig.4] is a schematic view of a thermal conditioning system according to a third embodiment of the invention,

[0085] [Fig.5] is a schematic view of the thermal conditioning system of [Fig.2], operating according to a first mode of operation, called 'heat pump with passenger compartment air extraction' mode,

[0086] [Fig.6] is a schematic view of the thermal conditioning system of [Fig.2], operating according to a second operating mode, called 'heat pump with energy recovery' mode,

[0087] [Fig.7] is a schematic view of the thermal conditioning system of the [Fig.4], operating according to a third mode of operation, called 'heat pump with energy recovery and cabin air extraction' mode,

[0088] [Fig.8] is a schematic view of the thermal conditioning system of the [Fig.2], operating according to a fourth mode of operation, called 'heat pump with accelerated passenger compartment heating' mode,

[0089] [Fig.9] is a schematic view of the thermal conditioning system of the [Fig.4], operating according to a fifth mode of operation, called 'heat pump with accelerated passenger compartment heating and passenger compartment air extraction' mode,

[0090] [Fig. 10] is a schematic view of the thermal conditioning system of [Fig.4], operating according to the third mode of operation, called 'heat pump with energy recovery and extraction of passenger air' mode. Description of the implementation methods

[0091] 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.

[0092] 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..

[0093] 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 or from the third element to the first element passes through the second element.

[0094] When it is specified that a subsystem includes a given element, this does not exclude the presence of other elements in that subsystem.

[0095] The thermal conditioning system 100, which will be described below, comprises an electronic control unit 60 that receives information from various sensors measuring, in particular, the characteristics of the refrigerant at various points in the circuit. The electronic control unit 60 also receives instructions from the vehicle occupants, such as the desired temperature inside the passenger compartment. The electronic control unit 60 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.

[0096] A compression device 7, also called a compressor, allows a refrigerant to circulate in a refrigerant circulation circuit 10. The compression device 7 can be an electric compressor, that is, a compressor whose moving parts are driven by an electric motor. The compression device 7 has a low-pressure refrigerant intake side, also called the inlet 7a of the compression device, and a high-pressure refrigerant discharge side, also called the outlet 7b of the compression device 7. The internal moving parts of the compressor 7 cause the refrigerant to pass from a low pressure at the inlet 7a to a high pressure at the outlet 7b. After expansion in one or more expansion chambers and circulation in at least part of the circuit, the refrigerant returns to the inlet 7a of the compressor 7 and begins a new thermodynamic cycle.

[0097] 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 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 or the other 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 included on each of these sections. 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 operating modes, as will be described later.

[0098] The refrigerant used by the refrigerant circuit 10 is a natural refrigerant, such as R744. R290 can also be used. It is also possible to use a chemical refrigerant, such as R1234yf or R134a.

[0099] Each refrigerant expansion device, also called an expansion valve, can be an electronic expansion valve. In an electronic expansion valve, the passage area through which the refrigerant flows can be continuously adjusted between a closed position and a maximum open position. To achieve this, an electronic control module drives an electric motor that moves a movable shutter, thus controlling the passage area available to the refrigerant. Closed-loop control of the movable shutter's position allows control of the refrigerant flow rate through the expansion valve.

[0100] Interior airflow refers to the flow of air into the passenger compartment of a motor vehicle. Interior airflow may circulate within a heating, ventilation, and / or air conditioning (HVAC) system. A vehicle may be equipped with several HVAC systems. For example, one system may manage the front area of ​​the passenger compartment, and another system may manage the rear area. These installations have not been shown in the various figures. One or more motor-fan units, not shown, are installed in each heating, ventilation and / or air conditioning system in order to increase, if necessary, the flow rate of the indoor air supplied by that system.

[0101] 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. Another motor-fan assembly, also not shown, can be activated to increase the flow rate of the external airflow Fe if necessary.

[0102] The airflow provided by each of the motor-fan groups can be adjusted in real time according to the heat exchange requirements, for example by the electronic control unit of the thermal conditioning system 100.

[0103] 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".

[0104] The heat transfer fluid circuit(s) also form one or more closed and sealed circuits in which a heat transfer fluid can circulate.

[0105] Figure [Fig.1] shows a thermal conditioning system 100 for a motor vehicle, according to a first embodiment. Thermal conditioning system 100 includes a refrigerant circuit 10 configured to circulate a refrigerant. The refrigerant circuit 10 comprises a main loop A including successively, according to the direction of refrigerant flow: - a compressor 7, - a first heat exchanger 1 thermally coupled with a first internal airflow Fil to a vehicle passenger compartment, - a first expansion valve 31, - a second expansion valve 32, - a second heat exchanger 2 configured thermally coupled with an external airflow Fe to the vehicle's passenger compartment, - a refrigerant fluid accumulation device 8. The refrigerant circuit 10 includes a first branch B connecting a first connection point 11 located on the main loop A downstream of the first expansion valve 31 and upstream of the second expansion valve 32 to a second connection point 12 located on the main loop A downstream of the second heat exchanger 2 and upstream of the storage device 8. The first branch B includes successively a third expansion valve 33 and a third heat exchanger 3. The refrigerant fluid circuit 10 includes a second branch C connecting a third connection point 13 located on the main loop A downstream of the first expansion valve 31 and upstream of the first connection point 11 to a fourth connection point 14 located on the main loop A downstream of the second connection point 12 and upstream of the storage device 8. The second branch of the C branch includes successively a fourth expansion valve 34 and a fourth heat exchanger 4 thermally coupled with the first internal airflow Fil.

[0106] The first exchanger 1 is configured to operate as a refrigerant fluid condenser. The first heat exchanger 1 is used to heat the passenger compartment of the vehicle. The first interior airflow, for example, is an airflow blown at the front part of the vehicle's passenger compartment.

[0107] Thermal coupling between the first exchanger 1 and the first internal airflow Fil can be ensured in different ways.

[0108] According to the embodiments illustrated in particular in figures 1 and 2, the first heat exchanger 1 is configured to exchange heat with the first interior airflow Fil to the passenger compartment of the vehicle. The thermal coupling between the first heat exchanger 1 and the first indoor airflow Fil is then said to be direct.

[0109] According to an alternative embodiment, illustrated in [Fig.3], the first heat exchanger 1 is configured to exchange heat with a heat transfer fluid circulating in a closed heat transfer fluid circuit 40, the heat transfer fluid circuit 40 comprising a heat exchanger IA configured to exchange heat with the first interior airflow Fil to the vehicle's passenger compartment.

[0110] The thermal coupling between the first heat exchanger 1 and the first internal airflow Fil is then said to be indirect, since it is achieved through a heat transfer fluid. The heat transfer fluid can be, for example, a mixture of water and glycol. The IA heat exchanger is called a heating radiator.

[0111] In the case of direct thermal coupling, the first heat exchanger 1 is disposed in a first heating, ventilation and / or air conditioning installation. In the case of indirect thermal coupling, the IA exchanger, known as a heating radiator, is placed in a first heating, ventilation and / or air conditioning installation.

[0112] The second exchanger 2 is configured to operate selectively as a refrigerant fluid condenser or as a refrigerant fluid evaporator. The second exchanger 2 allows to selectively dissipate heat into the outside airflow Fe, or receive heat from the outside airflow Fe.

[0113] Indeed, the second exchanger 2 can, depending on the operating mode selected, receive refrigerant fluid at high pressure and high temperature, or refrigerant fluid in liquid state and at low pressure.

[0114] As with the first exchanger 1, the thermal coupling between the second exchanger 2 and the outside air flow Fe can be ensured in different ways.

[0115] According to the embodiments illustrated in particular in figures 1 and 2, the second exchanger 2 is configured to exchange heat with the outside airflow Fe to the vehicle's passenger compartment.

[0116] The thermal coupling between the second exchanger 2 and the outside airflow Fe is thus said to be direct. The second interchange 2 is installed at the front of the vehicle, for example in the front panel just behind the grille, so as to directly receive the airflow resulting from the forward movement of the vehicle.

[0117] According to an alternative embodiment, illustrated in [Fig. 3], the second heat exchanger 2 is configured to exchange heat with a heat transfer fluid circulating in a closed heat transfer fluid circuit 50. The heat transfer fluid circuit 50 comprises a 2A heat exchanger configured to exchange heat with the outside airflow Fe to the vehicle's passenger compartment. The thermal coupling between the second exchanger 2 and the outside air flow Fe is then said to be indirect.

[0118] In the embodiment illustrated in [Fig. 3], the fourth heat exchanger 4 also performs an indirect heat exchange with the first internal airflow Fil. This indirect heat exchange takes place via a heat transfer fluid circulating in a heat transfer fluid circuit 40B. The fifth exchanger 5 performs with the second indoor airflow Fi2 a heat exchange which is also indirect, via a heat transfer fluid circulating in a 40C heat transfer fluid circuit. In the variant shown in [Fig. 3], heat exchangers 1, 2, 4, and 5 all perform indirect heat exchange. In the embodiments illustrated in the other figures, this exchange is direct for these heat exchangers. According to variants not shown, some exchangers may perform a direct heat exchange, and other exchangers may perform an indirect heat exchange.

[0119] According to the example illustrated here, the third heat exchanger 3 is configured to operate as a refrigerant fluid evaporator. Indeed, the third exchanger 3 can receive refrigerant fluid in liquid form and in a low-pressure state, coming from the third expansion valve 33.

[0120] The fourth heat exchanger 4 is configured to operate as a refrigerant fluid evaporator. The fourth exchanger 4 can indeed receive refrigerant fluid in liquid form and in a low-pressure state, coming from the fourth expansion valve 34.

[0121] The fourth heat exchanger 4 can cool the first interior airflow Fil to the passenger compartment, so as to cool a first part of the passenger compartment, for example the front part. The fourth exchanger 4, designated by the term first passenger compartment evaporator, is located in the first heating, ventilation and / or air conditioning system. The fourth exchanger 4 is arranged upstream of the first exchanger 1 according to a flow direction of the first internal air flow Fil.

[0122] According to the illustrated example, the third heat exchanger 3 is thermally coupled with an element 25 of an electric drive chain of a motor vehicle.

[0123] The third heat exchanger 3 allows the element 25 of the vehicle's electric powertrain to be cooled, or for the recovery of heat losses resulting from the operation of this element 25 of the powertrain to be made.

[0124] According to one embodiment, element 25 of the vehicle's electric drive chain includes an electrical energy storage battery. Alternatively, or in addition, element 25 of the vehicle's electric drivetrain includes a vehicle traction electric motor. Alternatively, or in addition, element 25 of the vehicle's electric drivetrain includes an electronic control unit for the vehicle traction electric motor.

[0125] The third heat exchanger 3 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 heat transfer fluid can be, for example, a mixture of water and glycol. Circuit 30 includes a pump, not shown, which allows the heat transfer fluid to circulate in circuit 30. The pump is, for example, an electric pump, which can be selectively switched on or off.

[0126] The fourth connection point 14 can be confused with the second connection point 12.

[0127] The quantity of refrigerant circulating in the circuit 10 varies according to the operating mode chosen, and according to ambient conditions. The refrigerant accumulation device 8 compensates for these variations in the quantity of refrigerant circulating in the circuit 10. The accumulation device 8 is designated by the term accumulator and serves as a refrigerant storage reserve.

[0128] Fig. 2 illustrates a second embodiment of the proposed thermal conditioning system 100.

[0129] According to this embodiment of the thermal conditioning system 100, the refrigerant circuit 10 includes a third branch D connecting a fifth connection point 15 located on the main loop A downstream of the first expansion valve 31 and upstream of the first connection point 11 to a sixth connection point 16 located on the second branch C downstream of the fourth heat exchanger 4 and upstream of the fourth connection point 14. The third branch D includes successively a fifth expansion valve 35 and a fifth heat exchanger 5 configured to exchange heat with a second indoor airflow Fi2.

[0130] The fifth heat exchanger 5 is configured to operate as a refrigerant fluid evaporator. Indeed, the fifth exchanger 5 can receive liquid and low-pressure refrigerant fluid from the fifth expansion valve 35.

[0131] The fifth heat exchanger 5, designated by the term second passenger compartment evaporator, allows the second interior airflow Fi2 to be cooled to the passenger compartment, so as to particularly cool a second area of ​​the passenger compartment. The second interior airflow Fi2, for example, is an airflow blown at the rear of the vehicle's passenger compartment. Passengers seated at the rear of the vehicle thus receive a direct flow of cooled air, in addition to the first airflow Fil blown at the front of the passenger compartment. The fifth heat exchanger 5 is, for example, located in a second heating, ventilation and / or air conditioning system, dedicated to the occupants of the rear seats of the vehicle.

[0132] The third branch of the bypass D here includes a sixth expansion valve 36 arranged downstream of the fifth heat exchanger 5. In other words, the third branch of the D branch successively comprises a fifth expansion valve 35, a fifth heat exchanger 5 configured to exchange heat with a second indoor airflow Fi2 and a sixth expansion valve 36.

[0133] The sixth expansion valve 36 allows the third exchanger 3 and the fifth exchanger 5 to operate at different evaporation pressures. In particular, the pressure in the fifth exchanger 5 can be higher than the pressure in the third exchanger 3, which allows the evaporation temperature to be controlled at a higher value than in the third exchanger 3.

[0134] The fifth connection point 15 is here confused with the third connection point 13.

[0135] The refrigerant circuit 10 includes a fourth branch E connecting a seventh connection point 17 located on the main loop A downstream of an outlet 7b of the compressor 7 and upstream of the first heat exchanger 1 to an eighth connection point 18 located on the main loop A downstream of the second heat exchanger 2 and upstream of the storage device 8. The fourth branch E includes a seventh expansion valve 37.

[0136] The fourth branch E allows refrigerant fluid from the compressor 7 to be sent to the second heat exchanger 2, in order to cool it, in particular for operating modes involving cooling of the vehicle's passenger compartment.

[0137] Fig. 4 illustrates a third embodiment of the proposed thermal conditioning system 100.

[0138] In this embodiment, the refrigerant circuit 10 comprises a fifth branch F connecting to a ninth connection point 19 located on the second branch C downstream of the fourth heat exchanger 4 and upstream of the fourth connection point 14 to a tenth connection point 20 located on the first branch of the bypass B downstream of the first connection point 11 and upstream of the first regulator 31.

[0139] The fifth branch F allows refrigerant at high pressure or intermediate pressure from the fourth exchanger 4 to be redirected to the second expansion valve 32 and the second exchanger 2, or to the third expansion valve 33 and the third exchanger 3. The fourth heat exchanger 4 can thus function as a refrigerant condenser and can heat the first interior airflow Fil. The first interior airflow Fil is therefore heated successively by the fourth heat exchanger 4 and by the first heat exchanger 1, which accelerates the heating of the passenger compartment.

[0140] In the embodiment, the second branch C includes a sixth regulator 36 disposed downstream of the ninth connection point 19. In other words, the sixth regulator 36 is disposed in this case on the second branch C between the fourth connection point 14 and the ninth connection point 19, and no longer on the third branch D between the fifth exchanger 5 and the sixth connection point 16.

[0141] According to the illustrated example, the ninth connection point 19 is coincident with the sixth connection point 16. According to an unrepresented variant, the tenth connection point 20 can be confused with the first connection point 11.

[0142] According to the second and third embodiment of the thermal conditioning system 100, the main loop A of the refrigerant circuit 10 includes an internal exchanger 6 configured to allow heat exchange between the refrigerant circulating between the first connection point 11 and the second expansion valve 32 and the refrigerant downstream of the storage device 8 and upstream of an inlet 7a of the compressor 7.

[0143] The internal exchanger 6 makes it possible to increase the enthalpy variation of the refrigerant during the thermodynamic cycle, and therefore to increase the thermal power that the thermal conditioning system 100 can provide.

[0144] The internal heat exchanger 6 has a first heat exchange section 6a arranged on the main loop A between the first connection point 11 and the second expansion valve 32. The internal heat exchanger 6 has a second heat exchange section 6b arranged on the main loop A downstream of the accumulator 8 and upstream of the inlet 7a of the compressor 7.

[0145] The internal heat exchanger 6 is configured to allow heat exchange between the refrigerant in the first heat exchange section 6a and the refrigerant in the second heat exchange section 6b. Depending on the operating modes, the refrigerant can circulate in the first heat exchange section 6a of the second expansion valve 32 towards the first connection point 11, or from the first connection point 11 towards the second expansion valve 32 and the second exchanger 2. The refrigerant flows through the second heat exchange section 6b of the storage device 8 to the inlet 7a of the compressor 7.

[0146] The refrigerant circuit 10 includes a set of shut-off valves and one-way valves allowing the circulation of refrigerant to be selectively allowed or stopped in different portions of the circuit 10, as well as in the corresponding heat exchanger(s).

[0147] The main loop A includes a first shut-off valve 41 arranged upstream of the first exchanger 1. The first shut-off valve 41 is located downstream of the seventh connection point 17.

[0148] The main loop A includes a second shut-off valve 42 disposed downstream of the second heat exchanger 2 and upstream of the second connection point 12. When the circuit 10 includes the fifth branch E, the second shut-off valve 42 is disposed between the eighth connection point 18 and the second connection point 12.

[0149] The first shut-off valve 41 is an electrically operated valve. The second shut-off valve 42 is an electrically operated valve. The first shut-off valve 41 is a two-way valve. The second shut-off valve 42 is a two-way valve. In other words, each shut-off valve includes exactly one refrigerant inlet and one refrigerant outlet. Each valve can, in the closed position, interrupt the flow of the refrigerant.

[0150] The refrigerant circuit 10 includes a first one-way valve 45 located on the second branch C. The first one-way valve 45 is configured to allow refrigerant flow through the first one-way valve 45 from the fourth heat exchanger 4 to the sixth connection point 16. The first one-way valve 45 is also configured to prohibit refrigerant flow through the first one-way valve 45 from the sixth connection point 16 to the fourth heat exchanger 4. In other words, the refrigerant can flow in the second branch of bypass C from the fourth exchanger 4 to the sixth connection point 16, but cannot flow from the sixth connection point 16 to the fourth exchanger 4.

[0151] In the case of the third embodiment, illustrated in [Fig.4], the main loop A includes a third shut-off valve 43 disposed between the fifth connection point 15 and the first connection point 11. The third shut-off valve 43 is a two-way, electrically operated valve.

[0152] According to this embodiment, the refrigerant circuit 10 includes a second one-way valve 46 disposed on the third branch branch D. The second one-way valve 46 is configured to allow refrigerant flow through the second one-way valve 46 from the fifth exchanger 5 to the sixth connection point 16, and is also configured to prohibit refrigerant flow through the second one-way valve 46 from the sixth connection point 16 to the fifth exchanger 5. In other words, the second one-way valve 46 allows refrigerant fluid to circulate in the third branch of the bypass D from the sixth connection point 16 to the fifth exchanger 5, and prohibits circulation in the opposite direction, i.e. from the fifth exchanger 5 to the sixth connection point 16. In this embodiment, the sixth regulator 36 is not present on the third branch of the bypass D.

[0153] According to this embodiment, the refrigerant circuit 10 includes a third one-way valve 47 disposed on the fifth branch F. The third one-way valve 47 is configured to allow refrigerant flow through the third one-way valve 47 from the ninth connection point 19 to the tenth connection point 20, and is configured to prohibit refrigerant flow through the third one-way valve 47 from the tenth connection point 20 to the ninth connection point 19. In other words, the fifth branch F can only be traversed in the direction from the ninth connection point 19 to the tenth connection point 20.

[0154] Each of the one-way valves 45, 46, 47 is a check valve. A check valve is a passive device, i.e., it does not require electrical control.

[0155] Alternatively, each of the one-way valves 45, 46, 47 can be an electrically operated valve.

[0156] The proposed thermal conditioning system circuit can operate in various modes. Some of these modes will now be described and illustrated in Figures 5 to 10.

[0157] In these figures, the portions of the circuit 10 in which a flow of refrigerant fluid circulates are shown in thick solid lines, while the portions in which the refrigerant fluid does not circulate are shown in thin dashed lines. The different arrows indicate the direction of refrigerant flow in the various portions of the circuit 10 through which a refrigerant flow passes.

[0158] In steady state, the time variation of the mass of refrigerant in a heat exchanger is zero, and the refrigerant flow rate downstream of a heat exchanger is equal to the refrigerant flow rate upstream of that heat exchanger. Similarly, there is no accumulation of refrigerant in an expansion valve, and the flow rate of refrigerant downstream of an expansion valve is equal to the flow rate upstream of that expansion valve.

[0159] Figure 5 schematically illustrates an operating method of the thermal conditioning system 100 of Figure 2, in a so-called 'heat pump with cabin air extraction' mode. According to this operating mode, an initial flow Qrl of refrigerant circulates in the compressor 7 where it is subjected to high pressure, and circulates in the main loop A, successively in the first heat exchanger 1 where it releases heat, in the first expansion valve 31, and divides into: - a second flow Qr2 circulating in the main loop A, successively in the second expansion valve 32 it undergoes expansion and passes to a low pressure lower than the high pressure, in the second exchanger 2 where it receives heat, - a third flow Qr3 circulating in the third branch of the bypass D, successively in the fifth expansion valve 35 where it undergoes expansion and passes to an intermediate pressure lower than the high pressure and higher than the low pressure, in the fifth exchanger 5 where it receives heat, in the sixth expansion valve 36 where it undergoes expansion and passes to a low pressure, and joins the refrigerant flow from the second exchanger 2. The total flow Qrl formed circulates in the accumulation device 8 and returns to the compressor 7.

[0160] The refrigerant can circulate in the first expansion valve 31 without undergoing expansion.

[0161] The refrigerant fluid can undergo expansion in the first expansion valve 31 and pass to an intermediate pressure lower than the high pressure and higher than the low pressure. The expansion rate achieved by the first expansion valve 31 allows control of the efficiency of the internal exchanger 6. Indeed, the efficiency of the heat exchange between the first heat exchange section 6a and the second heat exchange section 6b depends on the pressure at the inlet of the first heat exchange section 6a, which in this mode of operation is controlled by the first expansion valve 31.

[0162] In this operating mode: The flow rate of refrigerant fluid in the first branch of bypass B is zero. The refrigerant flow rate in the second branch of the bypass C is zero. The refrigerant flow rate in the fourth branch of the bypass E is zero. Indeed, the third regulator 33, the fourth regulator 34 and the seventh regulator 37 are all three in the closed position.

[0163] The first exchanger 1 heats the first internal airflow Fil. The second exchanger 2 evaporates part of the refrigerant fluid, the heat of vaporization being supplied by the outside air flow Fe. The fifth exchanger 5 also evaporates part of the refrigerant, the heat of vaporization being supplied by the second internal airflow Fi2. In other words, the heat from the second interior airflow Fi2 is partially recovered before this airflow leaves the passenger compartment, and helps to heat the first interior airflow Fil. The fourth heat exchanger 4 is thermally inactive, meaning there is no heat exchange between the refrigerant and the first internal airflow Fil. The internal heat exchanger 6 is thermally active, since both the first heat exchange section 6a and the second heat exchange section 6b carry a flow of refrigerant.

[0164] In this mode of operation, the passenger compartment is heated at the level of the first exchanger 1, from the heat taken from the outside airflow Fe, the heat taken from the second inside airflow Fi2, and the energy supplied to the refrigerant by the compressor 7.

[0165] The fifth connection point 15 is a refrigerant flow division point, that is, a point where the refrigerant flow arriving at the fifth connection point 15 splits into two flows, these two flows traveling through different portions of the circuit. The fifth connection point 15 can also be said to be a divergence point. The fourth connection point 14 is a point where two distinct flows Qr2, Qr3 meet, forming a single flow Qrl downstream. Alternatively, the fourth connection point 14 can be described as a flow convergence point.

[0166] Figure 6 schematically illustrates an operating method of the thermal conditioning system 100 of Figure 2, in a so-called 'heat pump with energy recovery' mode. In this operating mode, an initial flow Qrl of refrigerant circulates in the compressor 7 where it passes through a high pressure, and circulates in the main loop A, successively through the first heat exchanger 1 where it releases heat, through the first expansion valve 31 where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, and divides into: — a second flow Qr2 circulating in the main loop A, successively in the second expansion valve 32 it undergoes expansion and passes to a low pressure lower than the high pressure, in the second exchanger 2 where it receives heat, and — a third flow Qr3 circulating in the first branch of bypass B, successively in the third expansion valve 33 where it undergoes expansion and passes to low pressure, in the third exchanger 3 where it receives heat, and joins the flow of refrigerant fluid coming from the second exchanger 2. The total flow Qrl formed circulates in the accumulation device 8 and returns to the compressor 7.

[0167] In this operating mode, the second flow rate Qr2 may be greater than the third flow rate Qr3. For this purpose, the passage section of the second regulator 32 can be adjusted to a value greater than that of the passage section of the third regulator 33.

[0168] In this operating mode: The refrigerant flow rate in the second branch of the bypass C is zero. The refrigerant flow rate in the third branch of the bypass D is zero. The refrigerant flow rate in the fourth branch of the bypass E is zero.

[0169] The first exchanger 1 heats the first internal airflow Fil. The second exchanger 2 evaporates part of the refrigerant fluid, the heat of vaporization being supplied by the outside air flow Fe. The third exchanger 3 also evaporates part of the refrigerant, the heat of vaporization being supplied by the heat transfer fluid of circuit 30. The fourth heat exchanger 4 is thermally inactive, meaning there is no heat exchange between the refrigerant and the first indoor airflow Fil. The fifth heat exchanger 5 is thermally inactive, meaning there is no heat exchange between the refrigerant and the second indoor airflow Fi2.

[0170] In this mode of operation, the passenger compartment is heated at the level of the first exchanger 1, from the heat taken from the outside air flow Fe, from the recovery of the heat losses of the element 25, and from the energy supplied to the refrigerant fluid by the compressor 7.

[0171] The refrigerant used to recover heat losses from element 25 undergoes two successive expansions: the first as it passes through the first expansion valve 31 and the second as it passes through the third expansion valve 33. For the same total expansion level, allowing the transition from high pressure to low pressure, the opening of the third expansion valve 33 is greater than the opening that would be obtained if the third expansion valve 33 alone performed an expansion from high pressure to low pressure. The third expansion valve 33 can therefore operate within an opening range more favorable to precise control of the flow rate through it. Indeed, this opening range is far from the minimum opening of the third expansion valve, which allows for more precise control when the flow rate to be regulated is low. These two successive expansions are particularly useful when the thermal power to be recovered from the third exchanger 3 is low, for example less than 400W.

[0172] The first connection point 11 is a refrigerant flow division point. The second connection point 12 is a point where two distinct flows Qr2, Qr3 meet, forming a single flow Qrl downstream. The second connection point 12 is a point of convergence of the flows.

[0173] Fig. 7 schematically illustrates a method of operation of the thermal conditioning system 100 of Fig. 2, in a mode known as 'heat pump with energy recovery and extraction of passenger air'. In this operating mode, an initial flow Qrl of refrigerant circulates in the compressor 7 where it passes through high pressure, and circulates in the main loop A, successively in the first heat exchanger 1 where it releases heat, in the first expansion valve 31, and divides into: - a second flow Qr2 circulating in the main loop A, - a third flow Qr3 circulating in the third branch of the bypass D, successively in the fifth regulator 35 where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the fifth exchanger 5 where it receives heat, in the sixth regulator 36 where it undergoes expansion and passes to a low pressure lower than the intermediate pressure. The second flow rate Qr2 is divided into: - a fourth flow Qr4 circulating in the main loop A, successively in the second expansion valve 32 it undergoes expansion and passes to a low pressure lower than the high pressure, in the second exchanger 2 where it receives heat, and - a fifth flow Qr5 circulating in the first branch of bypass B, successively in the third expansion valve 33 where it undergoes expansion and passes to low pressure, in the third exchanger 3 where it receives heat, and joins the flow of refrigerant fluid from the sixth expansion valve 36 and the flow of refrigerant fluid from the second exchanger 2. The total flow Qrl formed circulates in the accumulation device 8 and returns to the compressor 7.

[0174] The refrigerant can flow through the first expansion valve 31 without undergoing expansion. The refrigerant can undergo expansion in the first expansion valve 31 and pass through an intermediate pressure lower than the high pressure and higher than the low pressure.

[0175] In this operating mode: The refrigerant flow rate in the second branch of the bypass C is zero. The refrigerant flow rate in the fourth branch of the bypass E is zero.

[0176] The first exchanger 1 heats the first internal airflow Fil. The second exchanger 2 evaporates part of the refrigerant fluid, the heat of vaporization being supplied by the outside air flow Fe. The third exchanger 3 also evaporates part of the refrigerant fluid, the heat of vaporization being supplied by the heat transfer fluid of the circuit 25, in which the heat losses related to the operation of element 25 are dissipated. The fifth exchanger 5 also carries out the evaporation of the refrigerant, the heat of vaporization being supplied by the second internal airflow Fi2. The fourth heat exchanger 4 is thermally inactive, that is to say there is no heat exchange between the refrigerant and the first interior airflow Fil.

[0177] In this operating mode, the passenger compartment is heated at the level of the first heat exchanger 1, from the heat extracted from the outside airflow Fe, the heat extracted from the second interior airflow Fi2, the heat losses of the traction chain element 25, and the energy supplied to the refrigerant by the compressor 7.

[0178] The fifth connection point 15 is a first point of division of the refrigerant flow. The first connection point 11 is a second point of division of the refrigerant flow. The fourth connection point 14, here confused with the second connection point 12, is a point where three distinct flows Qr3, Qr4, Qr5 meet, and form downstream a single flow Qrl.

[0179] Fig. 8 schematically illustrates a method of operation of the thermal conditioning system 100 of Fig. 4, in a mode known as 'heat pump with accelerated heating of the passenger compartment'. In this mode: - a first flow Qr of refrigerant fluid circulates in the compressor 7 where it passes through high pressure, and circulates in the main loop A, successively in the first exchanger 1 where it releases heat, in the first expansion valve 31, then circulates in the second bypass branch C, successively in the fourth expansion valve 34 where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the fourth exchanger 4 where it releases heat, then flows through the fifth branch F and rejoins the main loop A, then circulates successively in the second expansion valve 32 where it undergoes expansion and passes to a lower pressure than the high pressure, in the second exchanger 2 where it receives heat, in the accumulation device 8 and returns to the compressor 7.

[0180] In this operating mode: The third shut-off valve 43 is in the closed position. The refrigerant flow rate in the portion of the main loop A between the third connection point 13 and the first connection point 11 is therefore zero. The refrigerant flow rate in the third branch of the bypass D is zero. The refrigerant flow rate in the portion of the first branch of the bypass B between the tenth connection point 20 and the fourth connection point 14 is zero. The refrigerant flow rate in the fourth branch of the bypass E is zero.

[0181] The high-pressure refrigerant fluid heats the first internal airflow Fil at the level of the first exchanger 1. The intermediate pressure refrigerant fluid also heats the first interior airflow Fil at the fourth exchanger 4. The combined heating at these two exchangers 1,4 allows for accelerated heating of the passenger compartment. The second exchanger 2 carries out the evaporation of the refrigerant fluid, the heat of vaporization being supplied by the outside air flow Fe. The third exchanger 3 is thermally inactive. The fifth exchanger 5 is thermally inactive.

[0182] In this mode of operation, the first interior airflow Fil of the passenger compartment is heated at the level of the first exchanger 1 and the fourth exchanger 4, from the heat taken from the outside airflow Fe and the energy supplied to the refrigerant fluid by the compressor 7.

[0183] The refrigerant flow rate Qr does not divide. In steady state, the first heat exchanger 1, the fourth heat exchanger 4 and the second heat exchanger 2 are traversed by the same refrigerant flow rate, which is the flow rate discharged by the compressor 7.

[0184] Figure 9 illustrates a method of operation of the conditioning system thermal 100 of [Fig.4], in a mode called 'heat pump with passenger compartment preheating and passenger compartment air extraction' In this operating mode, an initial flow Qrl of refrigerant circulates in the compressor 7 where it is subjected to high pressure, and circulates in the main loop A, successively in the first heat exchanger 1 where it releases heat, in the first expansion valve 31, and is divided into: - a second flow Qr2 circulating in the second branch of the bypass C, successively in the fourth expansion valve 34 where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the fourth heat exchanger 4 where it releases heat, and — a third flow Qr3 circulating in the third branch of the bypass D, successively in the fifth expansion valve 35 where it undergoes expansion and passes to intermediate pressure, in the fifth exchanger 5 where it receives heat, and joins the flow of refrigerant fluid coming from the fourth exchanger 4. The total flow formed Qr4 circulates in the fifth branch of the bypass F and joins the main loop A, then circulates successively in the second expansion valve 32 where it undergoes expansion and passes to a lower pressure than the high pressure, in the second exchanger 2 where it receives heat, in the accumulation device 8 and returns to the compressor 7.

[0185] This mode of operation differs from the previous one in that between the third connection point 13 and the sixth connection point 16, the refrigerant from the first expansion valve 31 circulates in parallel in the fourth exchanger 4 and in the fifth exchanger 5. The third connection point 13 is a point of separation of the refrigerant flows, and the sixth connection point 16 is a point of convergence of the flows.

[0186] The intermediate pressure refrigerant circulating in the fourth exchanger 4 exchanges heat with the first internal air stream Fil which has not been heated by another heat exchanger, and condenses by giving up heat to the first internal air stream Fil. The intermediate pressure refrigerant circulating in the fifth exchanger 5 exchanges heat with the second indoor airflow Fi2 which is at a higher temperature than the first indoor airflow Fil, and evaporates, taking heat from the second indoor airflow Fi2. The intermediate pressure level is adjusted so as to obtain evaporation of the refrigerant in the fifth exchanger 5 and condensation in the fourth exchanger 4.

[0187] In this mode of operation, the first interior airflow Fil of the passenger compartment is heated at the level of the first exchanger 1 and the fourth exchanger 4, from the heat taken from the outside airflow Fe, the heat recovered from the second interior airflow Fi2, and the energy supplied to the refrigerant by the compressor 7.

[0188] The fifth connection point 15, here confused with the third connection point 13, is a refrigerant flow division point. The sixth connection point 16, here confused with the ninth connection point 19, is a point where two distinct flows Qr2, Qr3 meet, and form downstream a single flow Qr4. In steady state, the refrigerant flow rate is the same in the first exchanger 1 and in the second exchanger 2. The fourth exchanger 4 and the fifth exchanger 5 are traversed by a flow rate lower than that traversing exchangers 1, 2.

[0189] Fig. 10 illustrates an operating method of the thermal conditioning system 100 of Fig. 4, in a mode known as 'heat pump with energy recovery and extraction of passenger air'. In this operating mode, an initial flow Qrl of refrigerant circulates in the compressor 7 where it is subjected to high pressure, and circulates in the main loop A, successively in the first heat exchanger 1 where it releases heat, in the first expansion valve 31, and is divided into: - a second flow Qr2 circulating in the main loop A, - a third flow Qr3 circulating in the third branch of bypass D, successively in the fifth regulator 35 where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the fifth exchanger 5 where it receives heat, in the second branch of bypass C, in the sixth regulator 36 where it undergoes expansion and passes to a low pressure lower than the intermediate pressure. The second flow rate Qr2 is divided into: — a fourth flow Qr4 circulating in the main loop A, successively in the second expansion valve 32 it undergoes expansion and passes to low pressure, in the second exchanger 2 where it receives heat, and — a fifth flow Qr5 circulating in the first branch of bypass B, successively in the third expansion valve 33 where it undergoes expansion and passes to low pressure, in the third exchanger 3 where it receives heat, and joins the flow of refrigerant fluid from the sixth expansion valve 36 and the flow of refrigerant fluid from the second exchanger 2. The total flow formed Qrl circulates in the accumulation device 8 and returns to the compressor 7.

[0190] In this operating mode: The refrigerant can flow through the first expansion valve 31 without undergoing expansion. The third shut-off valve 43 is in the open position. The refrigerant flow rate in the fifth branch of the F branch is zero. Indeed, the one-way valve 47 prevents the high-pressure refrigerant arriving at the tenth connection point 20 from reaching the ninth connection point 19, which is at intermediate pressure. The refrigerant flow rate in the fourth branch E is zero.

[0191] The condensation of the high-pressure refrigerant at the first heat exchanger 1 heats the first internal airflow Fil. The third exchanger 3 evaporates part of the low-pressure refrigerant, with the heat of vaporization supplied by the heat transfer fluid of circuit 25. The fifth exchanger 5 carries out the evaporation of the intermediate pressure refrigerant fluid, the heat of vaporization being supplied by the second internal airflow Fi2. The second exchanger 2 also evaporates part of the low-pressure refrigerant, with the heat of vaporization supplied by the outside air flow Fe. The fourth heat exchanger 4 is thermally inactive, that is to say there is no heat exchange between the refrigerant and the first interior airflow Fil.

[0192] In this operating mode, the first interior airflow Fil of the passenger compartment is heated at the first heat exchanger 1, from the heat taken from the outside airflow Fe, the heat taken from the second interior airflow Fi2, the heat losses of the traction chain element 25 and from the energy supplied to the refrigerant by the compressor 7.

[0193] Many other modes of operation, not shown, are of course possible.

Claims

Demands

1. A thermal conditioning system (100) for a motor vehicle, 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 refrigerant flow: — a compressor (7), — a first heat exchanger (1) thermally coupled with a first interior airflow (Fil) to a vehicle passenger compartment, — a first expansion valve (31), — a second expansion valve (32), — a second heat exchanger (2) configured thermally coupled with an exterior airflow (Fe) to the vehicle passenger compartment, — a refrigerant accumulation device (8),- a first branch (B) connecting a first connection point (11) located on the main loop (A) downstream of the first expansion valve (31) and upstream of the second expansion valve (32) to a second connection point (12) located on the main loop (A) downstream of the second heat exchanger (2) and upstream of the storage device (8), the first branch (B) comprising successively a third expansion valve (33) and a third heat exchanger (3), - a second branch (C) connecting a third connection point (13) located on the main loop (A) downstream of the first expansion valve (31) and upstream of the first connection point (11) to a fourth connection point (14) located on the main loop (A) downstream of the second connection point (12) and upstream of the storage device (8),the second branch of the bypass (C) comprising successively a fourth expansion valve (34) and a fourth heat exchanger (4) thermally coupled with the first internal airflow (Fil).

2. Thermal conditioning system (100) according to claim 1, wherein the third heat exchanger (3) is thermally coupled with an element (25) of an electric drivetrain of a motor vehicle.

3. Thermal conditioning system (100) according to claim 1 or 2, wherein the refrigerant circuit (10) comprises a third branch (D) connecting a fifth connection point (15) disposed on the main loop (A) downstream of the first expansion valve (31) and upstream of the first connection point (11) to a sixth connection point (16) disposed on the second branch (C) downstream of the fourth exchanger (4) and upstream of the fourth connection point (14), the third branch (D) comprising successively a fifth expansion valve (35) and a fifth heat exchanger (5) configured to exchange heat with a second indoor airflow (Fi2).

4. Thermal conditioning system (100) according to any one of the preceding claims, wherein the refrigerant circuit (10) comprises a fourth branch (E) connecting a seventh connection point (17) located on the main loop (A) downstream of an outlet (7b) of the compressor (7) and upstream of the first heat exchanger (1) to an eighth connection point (18) located on the main loop (A) downstream of the second heat exchanger (2) and upstream of the storage device (8), the fourth branch (E) comprising a seventh expansion valve (37).

5. Thermal conditioning system (100) according to any one of the preceding claims, wherein the refrigerant circuit (10) has a fifth branch (F) connecting a ninth connection point (19) disposed on the second branch (C) downstream of the fourth exchanger (4) and upstream of the fourth connection point (14) to a tenth connection point (20) disposed on the first branch (B) downstream of the first connection point (11) and upstream of the third expansion valve (33).

6. Thermal conditioning system (100) according to any one of the preceding claims, wherein the main loop (A) of the refrigerant circuit (10) includes an internal exchanger (6) configured to permit heat exchange between the refrigerant circulating between the first connection point (11) and the second expansion valve (32) and the refrigerant downstream of the storage device (8) and upstream of an inlet (7a) of the compressor (7).

7. Thermal conditioning system (100) according to any one of the preceding claims in combination with claim 3, wherein the third bypass branch (D) comprises a sixth expansion valve (36) disposed downstream of the fifth heat exchanger (5).

8. A method of operating a thermal conditioning system (100) according to claim 7, in a so-called 'heat pump with cabin air extraction' mode in which: - a first flow (Qrl) of refrigerant circulates in the compressor (7) where it passes through a high pressure, and circulates in the main loop (A), successively in the first heat exchanger (1) where it releases heat, in the first expansion valve (31), and divides into: - a second flow (Qr2) circulating in the main loop (A), successively in the second expansion valve (32) where it undergoes expansion and passes through a low pressure lower than the high pressure, in the second heat exchanger (2) where it receives heat, - a third flow (Qr3) circulating in the third bypass branch (D), successively in the fifth expansion valve (35) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure and higher than the low pressure,in the fifth exchanger (5) where it receives heat, in the sixth expansion valve (36) where it undergoes expansion and drops to low pressure, and joins the refrigerant flow from the second exchanger (2), the total flow (Qrl) formed circulates in the accumulation device (8) and returns to the compressor (7).

9. A method of operating a thermal conditioning system (100) according to any one of claims 1 to 7, in a so-called 'heat pump with energy recovery' mode in which: - a first flow (Qrl) of refrigerant circulates in the compressor (7) where it passes through a high pressure, and circulates in the main loop (A), successively in the first heat exchanger (1) where it releases heat, in the first expansion valve (31) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, and divides into: - a second flow (Qr2) circulating in the main loop (A), successively in the second expansion valve (32) where it undergoes a

10. expansion and passes to a lower pressure below the high pressure, in the second exchanger (2) where it receives heat, and — a third flow (Qr3) circulating in the first bypass branch (B), successively in the third expansion valve (33) where it undergoes expansion and passes to a lower pressure, in the third exchanger (3) where it receives heat, and joins the refrigerant flow from the second exchanger (2), the total flow (Qrl) formed circulates in the accumulation device (8) and returns to the compressor (7), and in which the second flow (Qr2) is greater than the third flow (Qr3). Method of operating a thermal conditioning system (100) according to claim 7, in a so-called 'heat pump with energy recovery and cabin air extraction' mode in which: - A first flow (Qr1) of refrigerant circulates in the compressor (7) where it passes through a high-pressure area, and circulates in the main loop (A), successively through the first heat exchanger (1) where it releases heat, through the first expansion valve (31), and divides into: — a second flow (Qr2) circulating in the main loop (A), — a third flow (Qr3) circulating in the third bypass branch (D), successively through the fifth expansion valve (35) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, through the fifth heat exchanger (5) where it receives heat, through the sixth expansion valve (36) where it undergoes expansion and passes through a low pressure lower than the intermediate pressure, - the second flow (Qr2) divides into: — a fourth flow (Qr4) circulating in the main loop (A), successively in the second expansion valve (32) where it undergoes expansion and passes to a low pressure lower than the high pressure, in the second exchanger (2) where it receives heat, and — a fifth flow (Qr5) circulating in the first bypass branch (B), successively in the third expansion valve (33) where it undergoes expansion and passes to a low pressure, in the third exchanger (3) where it receives heat, and joins the refrigerant flow from the sixth expansion valve (36) and the refrigerant flow from the second exchanger (2),

11.

12. the total flow (Qrl) formed circulates in the accumulation device (8) and returns to the compressor (7). Method of operating a thermal conditioning system (100) according to any one of claims 1 to 6 in combination with claim 5, in a so-called 'heat pump with accelerated passenger compartment heating' mode in which: - a first flow (Qrl) of refrigerant circulates in the compressor (7) where it passes to high pressure, and circulates in the main loop (A), successively in the first exchanger (1) where it gives up heat, in the first expansion valve (31), then circulates in the second bypass branch (C), successively in the fourth expansion valve (34) where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the fourth exchanger (4) where it gives up heat, then circulates in the fifth bypass branch (F) and rejoins the main loop (A), then circulates successively in the second expansion valve (32) where it undergoes expansion and passes to a low pressure lower than the high pressure, in the second exchanger (2) where it receives heat, in the accumulation device (8) and returns to the compressor (7).Method of operating a thermal conditioning system (100) according to any one of claims 1 to 6 in combination with claims 3 and 5, in a mode known as 'heat pump with passenger compartment preheating and passenger compartment air extraction' in which: - a first flow (Qrl) of refrigerant circulates in the compressor (7) where it passes through high pressure, and circulates in the main loop (A), successively in the first heat exchanger (1) where it releases heat, in the first expansion valve (31), and divides into: — a second flow (Qr2) circulating in the second bypass branch (C), successively in the fourth expansion valve (34) where it undergoes expansion and passes through an intermediate pressure lower than the high pressure, in the fourth heat exchanger (4) where it releases heat, and — a third flow (Qr3) circulating in the third branch of the bypass (D), successively in the fifth expansion valve (35) where it undergoes expansion and passes to intermediate pressure, in the fifth exchanger (5) where it receives heat,

13. and joins the refrigerant flow from the fourth heat exchanger (4), The total flow formed circulates in the fifth branch of the bypass (F) and rejoins the main loop (A), then circulates successively through the second expansion valve (32) where it undergoes expansion and passes to a low pressure lower than the high pressure, through the second heat exchanger (2) where it receives heat, through the storage device (8) and returns to the compressor (7). Method of operating a thermal conditioning system (100) according to any one of claims 1 to 6 in combination with claim 3, in a mode known as 'heat pump with energy recovery and cabin air extraction' in which: - a first flow (Qr1) of refrigerant circulates through the compressor (7) where it passes to a high pressure, and circulates through the main loop (A), successively through the first heat exchanger (1) where it releases heat, through the first expansion valve (31), and divides into: — a second flow (Qr2) circulating in the main loop (A), — a third flow (Qr3) circulating in the third branch (D),successively in the fifth pressure regulator (35) where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the fifth heat exchanger (5) where it receives heat, in the second bypass branch (C), in a sixth pressure regulator (36) where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, - the second flow rate (Qr2) is divided into: — a fourth flow (Qr4) circulating in the main loop (A), successively in the second expansion valve (32) where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, in the second heat exchanger (2) where it receives heat, and — a fifth flow (Qr5) circulating in the first branch of the bypass (B), successively in the third expansion valve (33) where it undergoes expansion and passes to low pressure, in the third exchanger (3) where it receives heat, and joins the flow of refrigerant fluid from the sixth expansion valve (36) and the flow of refrigerant fluid from the second exchanger (2), the total flow (Qrl) formed circulates in the accumulation device (8) and returns to the compressor (7).

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