Thermal conditioning system

Abstract

The invention relates to a thermal conditioning system (100) for a motor vehicle, comprising a refrigerant circuit (10) including: - a main loop (A) comprising successively a first compressor (7), a first heat exchanger (1), a first expansion valve (21), a second heat exchanger (2), - a bypass branch (B) arranged in parallel with the first heat exchanger and comprising successively a second expansion valve (22), a third heat exchanger (3), a second compressor (8), - an internal heat exchanger (4) comprising a first heat exchange section (5) allowing heat exchange between the refrigerant from the first heat exchanger (1) and the refrigerant from the third heat exchanger (3),and a second heat exchange section (6) allowing heat exchange between the refrigerant from the first heat exchange section (5) and the refrigerant from the second exchanger (2). 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 various heat exchangers arranged in the refrigerant circuit. Previous technique

[0002] Thus, the high-pressure refrigerant discharged by the compressor can release heat to the outside air and then be expanded to a low-pressure state. The low-pressure refrigerant can circulate in parallel through two different heat exchangers where it evaporates, thereby cooling two different components or subsystems.

[0003] When the required cooling capacity increases, the use of a single compressor may prove insufficient. It is therefore known to use two compressors that can operate in parallel; that is, a first compressor receives the low-pressure refrigerant from a first heat exchanger, and a second compressor receives the low-pressure refrigerant from a second heat exchanger. The refrigerant flow rate in each heat exchanger can thus be better adapted to the cooling requirement. A higher cooling capacity can therefore be provided, and achieving different temperature levels between the two heat exchangers is facilitated.

[0004] However, it is desirable to have thermal conditioning systems with even improved efficiency, offering for example higher thermal power, or better compactness. Summary

[0005] To this end, a thermal conditioning system for motor vehicles is proposed, comprising a refrigerant circuit configured to circulate a refrigerant fluid, the refrigerant circuit comprising: - a main refrigerant circulation loop comprising successively, according to a direction of refrigerant circulation: — a first compressor, — a first heat exchanger thermally coupled with a first airflow, — a first expansion valve, — a second heat exchanger thermally coupled with a second airflow, - a branch connecting a first connection point located on the main loop downstream of the first heat exchanger and upstream of the first expansion valve to a second connection point located on the main loop downstream of the first compressor and upstream of the first heat exchanger, the branch comprising successively: — a second regulator, — a third heat exchanger thermally coupled with a heat transfer fluid, — a second compressor, - an internal heat exchanger comprising: — a first heat exchange section arranged jointly on the main loop and on the bypass branch, configured to allow heat exchange between the refrigerant circulating between the first exchanger and the first connection point and the refrigerant circulating between the third exchanger and an inlet of the second compressor, — a second heat exchange section arranged on the main loop, configured to allow heat exchange between the refrigerant circulating between the first heat exchange section and the refrigerant circulating between the second exchanger and an inlet of the first compressor.

[0006] The presence of an internal exchanger acting on the refrigerant drawn in by the first compressor as well as on the refrigerant drawn in by the second compressor makes it possible to increase the efficiency of the thermodynamic cycle and therefore of the thermal conditioning system.

[0007] The features listed in the following paragraphs can be implemented independently of each other or in any technically possible combination:

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

[0009] The second exchanger is configured to operate as a refrigerant fluid evaporator.

[0010] The third exchanger is configured to operate as a refrigerant fluid evaporator.

[0011] According to one aspect of the thermal conditioning system, the first heat exchange section and the second heat exchange section are integrated into a common body.

[0012] The internal heat exchanger is thus particularly compact, which facilitates its integration into the vehicle. Its heat exchange efficiency can also be optimized thanks to this integration into a common body.

[0013] According to one embodiment of the thermal conditioning system, the first heat exchange section and the second heat exchange section form a non-removable assembly.

[0014] The first heat exchange section comprises a first compartment located on the main loop downstream of the first heat exchanger and upstream of the first connection point, and a second heat exchange compartment located on the bypass branch downstream of the third heat exchanger and upstream of an inlet of the second compressor. The refrigerant circulating in the first heat exchange compartment can exchange heat with the refrigerant circulating in the second heat exchange compartment.

[0015] The second heat exchange section comprises a first heat exchange compartment disposed on the main loop downstream of the first heat exchange compartment of the first heat exchange section and a second heat exchange compartment disposed on the main loop downstream of the second exchanger and upstream of an inlet of the first compressor.

[0016] According to one embodiment, the internal exchanger is a plate exchanger.

[0017] According to one embodiment of the thermal conditioning system, the body of the internal exchanger is formed by a plurality of plates stacked in a stacking direction, a space separating two consecutive plates defining a refrigerant circulation channel, and: A refrigerant circulation channel from the first heat exchange section is interposed, according to the stacking direction, between two consecutive refrigerant circulation channels from the second heat exchange section.

[0018] Similarly, a refrigerant circulation channel of the second heat exchange section is intercalated, according to the stacking direction, between two consecutive refrigerant circulation channels of the first heat exchange section.

[0019] Preferably, the first heat exchange section of the internal exchanger is a counter-current exchanger.

[0020] Similarly, the second heat exchange section of the internal exchanger is preferably a counter-current exchanger.

[0021] The refrigerant circulating in the first heat exchange compartment of the first heat exchange section and the refrigerant circulating in the second heat exchange compartment of the first heat exchange section flow predominantly in opposite directions.

[0022] The refrigerant circulating in the first heat exchange compartment of the second heat exchange section and the refrigerant circulating in the second heat exchange compartment of the second heat exchange section flow predominantly in opposite directions.

[0023] The internal exchanger has three refrigerant fluid inlets.

[0024] The internal exchanger has three refrigerant outlets.

[0025] The first inlet is arranged at the inlet of the first heat exchange compartment of the first heat exchange section.

[0026] The second inlet is arranged at the inlet of the second heat exchange compartment of the first heat exchange section.

[0027] The third inlet is arranged at the inlet of the second heat exchange compartment of the second heat exchange section.

[0028] The first outlet is located at the outlet of the first heat exchange compartment of the second heat exchange section.

[0029] The second outlet is arranged at the outlet of the second heat exchange compartment of the first heat exchange section.

[0030] The third outlet is arranged at the outlet of the second heat exchange compartment of the second heat exchange section.

[0031] The outlet of the first heat exchange compartment of the first heat exchange section and the inlet of the first heat exchange compartment of the second heat exchange section are internal to the internal exchanger.

[0032] According to an example embodiment of the thermal conditioning system, the main loop includes an accumulation device located downstream of the first exchanger and upstream of the first heat exchange section of the internal exchanger.

[0033] According to one variant, the main loop includes a first accumulation device disposed downstream of the second exchanger and upstream of the second heat exchange section of the internal exchanger.

[0034] Alternatively, or in a complementary manner, the bypass branch includes a second accumulation device located downstream of the third exchanger and upstream of the first heat exchange section of the internal exchanger.

[0035] According to one embodiment of the thermal conditioning system, the first airflow is an airflow from outside a passenger compartment of the vehicle.

[0036] According to one embodiment, the first exchanger is configured to exchange heat with the outside airflow.

[0037] According to one variant, the first exchanger is configured to exchange heat with a heat transfer fluid circulating in a heat transfer fluid circuit, and the heat transfer fluid circuit includes an exchanger configured to exchange heat with the outside airflow.

[0038] According to one embodiment of the thermal conditioning system, the second airflow is an interior airflow to a passenger compartment of the vehicle.

[0039] According to one embodiment, the second exchanger is configured to exchange heat with the internal airflow.

[0040] According to one variant, the second exchanger is configured to exchange heat with a heat transfer fluid circulating in a heat transfer fluid circuit, in which the heat transfer fluid circuit includes an exchanger configured to exchange heat with the internal airflow.

[0041] According to one embodiment, the third heat exchanger is thermally coupled with an element of an electric powertrain of the vehicle.

[0042] According to one example of implementation of the thermal conditioning system, the heat transfer fluid is a heat transfer fluid from a heat transfer fluid circuit, the element of the vehicle's electric powertrain being configured to exchange heat with the heat transfer fluid of the circuit.

[0043] The element of the vehicle's electric powertrain includes an electrical energy storage battery.

[0044] The element of the vehicle's electric drive chain includes an electric vehicle traction motor.

[0045] The element of the vehicle's electric drive chain includes an electronic control unit for the vehicle's electric traction motor.

[0046] According to an unrepresented variant, the second heat exchanger is thermally coupled with an element of an electric drive chain of the vehicle.

[0047] According to this variant, the third exchanger is configured to exchange heat with a heat transfer fluid circulating in a heat transfer fluid circuit, in which the heat transfer fluid circuit includes an exchanger configured to exchange heat with the internal airflow.

[0048] 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 first compression device where it passes under high pressure, - a second flow of refrigerant circulates in the second compression device where it passes under high pressure, The first and second flows join together to form a third flow of high-pressure refrigerant. This third flow circulates successively through the first heat exchanger where it releases heat, through the first heat exchange section of the internal heat exchanger, through the second heat exchange section of the internal heat exchanger, and then divides into: — a fourth flow of refrigerant circulating in the bypass branch, and — a fifth flow of refrigerant circulating in the main loop, - the fourth flow of refrigerant circulates successively in the second expansion valve where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the third heat exchanger where it evaporates, in the first heat exchange section of the internal heat exchanger, then returns to the inlet of the second compressor, - the fifth flow of refrigerant circulates successively in the first expansion valve where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, in the second exchanger where it evaporates, in the second heat exchange section of the internal exchanger, then returns to the inlet of the first compressor.

[0049] The high-pressure refrigerant from the first heat exchanger, circulating in the high-pressure section of the first heat exchanger section of the internal heat exchanger, therefore exchanges heat with the intermediate-pressure refrigerant, i.e., the warmer of the two refrigerants: the one from the second heat exchanger and the one from the third heat exchanger. The high-pressure refrigerant circulating in the high-pressure section of the second heat exchanger section, after having released heat in the first heat exchanger section and thus cooled, then exchanges heat with the low-pressure refrigerant, i.e., the cooler of the two refrigerants: the one from the second heat exchanger and the one from the third heat exchanger.The hottest high-pressure refrigerant thus exchanges heat with the hottest expanded refrigerant, while the coolest high-pressure refrigerant exchanges heat with the coolest expanded refrigerant. This configuration is favorable to overall thermal efficiency. Brief description of the drawings

[0050] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0051] [Fig-1] is a schematic view of an example of a conditioning system thermal according to the invention,

[0052] [Fig.2] is a schematic view detailing the inlets / outlets of the internal heat exchanger of the thermal conditioning system of [Fig.1],

[0053] [Fig.3] is a schematic view of a first embodiment of the system of thermal conditioning of the [Fig.l],

[0054] [Fig.4] is a schematic view of a second embodiment of the system of thermal conditioning of the [Fig.2],

[0055] [Fig.5] is a schematic view of the thermal conditioning system of the [Fig.3], operating according to a first mode of operation,

[0056] [Fig.6] is a schematic view of an embodiment of the internal heat exchanger of the proposed thermal conditioning system,

[0057] [Fig.7] is another schematic view of an embodiment of the exchanger internal to the proposed thermal conditioning system. Description of the implementation methods

[0058] 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 a priority of one element or parameter over another, and the designations may be interchanged.

[0059] 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, then returns to the compression device, possibly after passing through other elements.

[0060] 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.

[0061] When it is specified that a subsystem includes a given element, this does not exclude the presence of other elements in that subsystem.

[0062] The thermal conditioning system 100, which will be described below, includes an electronic control unit (not shown) that receives information from various 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 implements control laws to operate the various actuators in order to control the thermal conditioning system 100 and ensure compliance with the received instructions.

[0063] A compression device 7 allows a refrigerant to circulate in a refrigerant circulation circuit 10. The refrigerant circuit 10 forms a closed loop 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.

[0064] The refrigerant used by the refrigerant circuit 10 is a natural refrigerant, such as R290. A chemical refrigerant such as R1234yf or R134a can also be used. Another natural refrigerant, such as R744, can also be used.

[0065] Each refrigerant expansion device, also called an expansion valve, can be an electronic expansion valve. In an electronic expansion valve, the passage cross-section The opening for the refrigerant can be continuously adjusted between a minimum and maximum opening position. An electronic control module drives an electric motor that moves a movable shutter, thus controlling the passage area available to the refrigerant. The minimum opening position can be a closed position, meaning the passage area is zero and the refrigerant flow through the expansion valve is zero.

[0066] 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 fan-motor unit, not shown, is located within the HVAC system to increase the flow rate of the interior airflow Fi if necessary.

[0067] 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 of the climate control system 100.

[0068] 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".

[0069] The heat transfer fluid circuit(s) also form one or more closed and sealed circuits in which a heat transfer fluid can circulate.

[0070] Figure [Fig.1] shows a thermal conditioning system 100 for a motor vehicle. The thermal conditioning system 100 includes a refrigerant circuit 10 configured to circulate a refrigerant. The refrigerant circuit 10 comprises a main refrigerant circulation loop A, which includes, successively according to the direction of refrigerant circulation: - a first compressor 7, - a first heat exchanger 1 thermally coupled with a first airflow Fl, - a first regulator 21, - a second heat exchanger 2 thermally coupled with a second airflow F2. The refrigerant circuit 10 includes a branch B connecting a first connection point 11 located on the main loop A downstream of the first exchanger 1 and upstream of the first expansion valve 21 to a second connection point 12 located on the main loop A downstream of the first compressor 7 and upstream of the first exchanger 1. Branch B comprises successively: - a second regulator 22, - a third heat exchanger 3 thermally coupled with a heat transfer fluid F3, - a second compressor 8. The refrigerant circuit 10 includes an internal heat exchanger 4 comprising: - a first heat exchange section 5 arranged jointly on the main loop A and on the bypass branch B, configured to allow heat exchange between the refrigerant circulating between the first exchanger 1 and the first connection point 11 and the refrigerant circulating between the third exchanger 3 and an inlet 8a of the second compressor 8, — a second heat exchange section 6 arranged on the main loop A, configured to allow heat exchange between the refrigerant circulating between the first heat exchange section 5 and the refrigerant circulating between the second exchanger 2 and an inlet 7a of the first compressor 7.

[0071] The presence of an internal exchanger acting on the refrigerant drawn in by the first compressor 7 as well as on the refrigerant drawn in by the second compressor 8 makes it possible to increase the coefficient of performance of the thermodynamic cycle and therefore the efficiency of the thermal conditioning system.

[0072] The first compressor 7 is configured to provide a first flow of high-pressure refrigerant. The second compressor 8 is configured to provide a second flow of high-pressure refrigerant.

[0073] The first exchanger 1 is configured to operate as a refrigerant fluid condenser. Indeed, the first exchanger 1 receives high-pressure, high-temperature refrigerant fluid discharged by the first compressor 7 or the second compressor 8. The second exchanger 2 is configured to operate as a refrigerant fluid evaporator. The second exchanger 2 can indeed receive low-pressure refrigerant fluid, expanded by the first expansion valve 21. The third exchanger 3 is configured to operate as a refrigerant fluid evaporator. The third exchanger 3 can indeed receive low-pressure refrigerant fluid, expanded by the second expansion valve 22.

[0074] According to one aspect of the proposed thermal conditioning system 100, the first heat exchange section 5 and the second heat exchange section 6 are integrated into a common body 15.

[0075] The internal heat exchanger 4 can therefore be particularly compact. This facilitates the integration of the internal heat exchanger 4 into the vehicle. Furthermore, the heat exchange efficiency can also be optimized thanks to this integration into a common body.

[0076] According to one embodiment of the thermal conditioning system 100, the first heat exchange section 5 and the second heat exchange section 6 form a non-removable assembly.

[0077] In nominal operating conditions, the first heat exchange section 5 and the second heat exchange section 6 form a non-dismountable assembly. For the purposes of this application, a dismountable assembly is one whose individual components can be disassembled without being destroyed and can then be reassembled, restoring the assembly's functionality. A non-dismountable assembly is one in which disassembling the individual components damages or destroys those components. The assembly thus loses its functionality upon disassembly.

[0078] The first heat exchange section 5 includes a first compartment 5A arranged on the main loop A downstream of the first heat exchanger 1 and upstream of the first connection point 11. The first heat exchange section 5 includes a second heat exchange compartment 5B arranged on the bypass branch B downstream of the third heat exchanger 3 and upstream of an inlet 8a of the second compressor 8. The refrigerant circulating in the first heat exchange compartment 5A can exchange heat with the refrigerant circulating in the second heat exchange compartment 5B.

[0079] The second heat exchange section 6 includes a first heat exchange compartment 6A disposed on the main loop A downstream of the first heat exchange compartment 5A of the first heat exchange section 5. The second heat exchange section 6 includes a second heat exchange compartment 6B disposed on the main loop A downstream of the second exchanger 2 and upstream of an inlet 7a of the first compressor 7.

[0080] The first compartment 5A and the second compartment 5B of the first heat exchange section 5 are heat exchange compartments. Similarly, the first compartment 6A and the second compartment 6B of the second heat exchange section 6 are heat exchange compartments.

[0081] According to one embodiment, the internal exchanger 4 is a plate exchanger.

[0082] Fig. 6 and Fig. 7 schematically represent an example of an embodiment of the internal exchanger 4. In these figures, the X, Y, and Z directions represent three orthogonal directions in space. The orientation in space of the internal exchanger 4 is arbitrary in these figures, and the internal exchanger could be oriented differently.

[0083] According to this embodiment, the body 15 of the internal exchanger 4 is formed by a plurality of plates 16, 16' stacked along a stacking direction Z, a space separating two consecutive plates 16,16' defining a refrigerant circulation channel. A refrigerant circulation channel from the first heat exchange section 5 is intercalated, along the stacking direction Z, between two consecutive refrigerant circulation channels from the second heat exchange section 6.

[0084] Similarly, a refrigerant circulation channel of the second heat exchange section 6 is interposed, along the stacking direction Z, between two consecutive refrigerant circulation channels of the first heat exchange section 5.

[0085] In other words, one face of a given plate forms a wall for a circulation channel of the first heat exchange section 5, and the opposite face of this plate forms a wall for a circulation channel of the second heat exchange section 6. A heat exchange can therefore take place between the first heat exchange section 5 and the second heat exchange section 6, by heat transfer between the two sides of each wall.

[0086] The plates 16, 16' are, for example, made of aluminum or copper. The stack of plates 16, 16' is, for example, brazed so as to ensure the sealing and mechanical strength of the internal heat exchanger 4.

[0087] Preferably, the first heat exchange section 5 of the internal exchanger 4 is a counter-current exchanger. Similarly, the second heat exchange section 6 of the internal exchanger 4 is preferably a counter-current exchanger.

[0088] In other words, the refrigerant circulating in the first heat exchange compartment 5A of the first heat exchange section 5 and the refrigerant circulating in the second heat exchange compartment 5B of the first heat exchange section 5 flow predominantly in opposite directions. Similarly, the refrigerant circulating in the first heat exchange compartment 6A of the second heat exchange section 6 and the refrigerant circulating in the second heat exchange compartment 6B of the second heat exchange section 6 flow predominantly in opposite directions.

[0089] Figure [Fig.2] schematically details the internal exchanger 4. Internal heat exchanger 4 has three refrigerant inlets E1, E2, E3. Internal heat exchanger 4 has three refrigerant outlets S1, S2, S3.

[0090] The first inlet El is arranged at the inlet of the first heat exchange compartment 5A of the first heat exchange section 5. The second inlet E2 is located at the inlet of the second heat exchange compartment 5B of the first heat exchange section 5. The third inlet E3 is located at the inlet of the second heat exchange compartment 6B of the second heat exchange section 6.

[0091] The first SI outlet is arranged at the outlet of the first heat exchange compartment 6A of the second heat exchange section 6. The second outlet S2 is located at the outlet of the second heat exchange compartment 5B of the first heat exchange section 5. The third outlet S3 is located at the outlet of the second heat exchange compartment 6B of the second heat exchange section 6.

[0092] As schematically shown in Figures 6 and 7, portions 17 of the plates 16 form passageways between two consecutive flow channels of the low-pressure refrigerant fluid, each flow channel being formed by the space between two adjacent plates 16, 16'. Similarly, portions 17' of the plates 16' form passageways between two consecutive flow channels of the second heat exchange compartment 5B of the first heat exchange section 5. Portions 17” of the plates 16’ form passage conduits between two consecutive flow channels of the second heat exchange compartment 6B of the second heat exchange section 6.

[0093] Protuberances 18 formed on the plates 16' form partitions separating the second heat exchange compartment 5B from the first heat exchange section 5 and the second heat exchange compartment 6B from the second heat exchange section 6.

[0094] The symbol Cl indicates the circulation of the high-pressure refrigerant fluid in the first heat exchange compartment 5A of the first heat exchange section 5 and in the first heat exchange compartment 6A of the second heat exchange section 6. The symbol C5B designates the circulation of the refrigerant fluid at intermediate or low pressure in the second heat exchange compartment 5B of the first heat exchange section 5. The symbol C6B designates the circulation of the refrigerant fluid at low pressure or intermediate pressure in the second heat exchange compartment 6B of the second heat exchange section 6.

[0095] Each refrigerant inlet E1, E2, E3 of the internal heat exchanger 4 includes, for example, a connection fitting, not shown. A hose or tube is connected to the fitting in a sealed manner and forms a portion of the refrigerant circuit 10. Similarly, each refrigerant outlet SI, S2, S3 may include a connecting fitting, also not shown. A hose or tube is connected to the fitting in a sealed manner and forms a portion of the refrigerant circuit 10.

[0096] The outlet of the first heat exchange compartment 5A of the first heat exchange section 5 and the inlet of the first heat exchange compartment 6A of the second heat exchange section 6 are internal to the internal heat exchanger 4.

[0097] In other words, the outlet of the first heat exchange compartment 5A of the first heat exchange section 5 and the inlet of the first heat exchange compartment 6A of the second heat exchange section 6 are inaccessible from outside the internal heat exchanger 4.

[0098] This refrigerant outlet and inlet are formed by one of the passage orifices 17 allowing passage from a channel formed by the space between two adjacent plates to the channel formed by the space between the following plates in the stack of plates.

[0099] The internal heat exchanger 4 can also be constructed differently. For example, the internal heat exchanger 4 can be a tubular heat exchanger.

[0100] According to an example embodiment of the thermal conditioning system 100, illustrated in [Fig.3], the main loop includes an accumulation device 9 located downstream of the first exchanger 1 and upstream of the first heat exchange section 5 of the internal exchanger 4. The accumulation device 9 makes it possible to compensate, depending on the operating conditions, for variations in the quantity of refrigerant circulating in the refrigerant circuit. In this case, the accumulation device 9 is a desiccant bottle.

[0101] According to a variant shown in [Fig.4], the main loop A includes a first accumulation device 9' disposed downstream of the second exchanger 2 and upstream of the second heat exchange section 6 of the internal exchanger 4.

[0102] Alternatively, or in a complementary manner, the branch branch B includes a second accumulation device 9” disposed downstream of the third exchanger 3 and upstream of the first heat exchange section 5 of the internal exchanger 4.

[0103] The first storage device 9' is a storage device. Similarly, the second storage device 9" is a storage device. According to the example shown in [Fig. 4], both the first 9' accumulator and the second 9" accumulator are present. No desiccant bottle is used.

[0104] According to one embodiment of the thermal conditioning system 100, illustrated in [Fig.3], the first airflow Fl is an outside airflow Fe to a passenger compartment of the vehicle. The first exchanger 1 thus allows the heat of condensation of the high-pressure refrigerant fluid to dissipate into the outside air.

[0105] The thermal coupling between the first exchanger 1 and the outside air flow Fe can be ensured in different ways.

[0106] According to an example of an embodiment, illustrated in [Fig.3], the first exchanger 1 is configured to exchange heat with the outside air flow Fe. The thermal coupling is in this case said to be direct.

[0107] According to another embodiment, illustrated in [Fig. 4], the first heat exchanger 1 is configured to exchange heat with a heat transfer fluid circulating in a heat transfer fluid circuit 20, and the heat transfer fluid circuit 20 includes a heat exchanger IA configured to exchange heat with the outside airflow Fe. In this case, the thermal coupling between the first heat exchanger 1 and the outside airflow Fe is said to be indirect, since the thermal coupling takes place via a heat transfer fluid. The heat transfer fluid in circuit 20 is, for example, a mixture of water and glycol. A circulation pump, not shown, circulates the heat transfer fluid in circuit 20. The circulation pump is, for example, an electrically driven pump.

[0108] According to one embodiment of the thermal conditioning system 100, the second airflow F2 is an interior airflow Fi to a vehicle passenger compartment. The second heat exchanger 2 thus allows the vehicle passenger compartment to be cooled.

[0109] As before, the thermal coupling between the indoor airflow Fi and the second exchanger 2 can be ensured in different ways.

[0110] According to the example illustrated in [Fig.2], the second exchanger 2 is configured to exchange heat with the internal airflow Fi.

[0111] According to one variant, illustrated in [Fig.3], the second exchanger 2 is configured to exchange heat with a heat transfer fluid circulating in a heat transfer fluid circuit 30, and the heat transfer fluid circuit 30 includes an exchanger 2A configured to exchange heat with the internal airflow Fi. As with circuit 20, the heat transfer fluid in circuit 30 is, for example, a mixture of water and glycol.

[0112] According to one embodiment, the third heat exchanger 3 is thermally coupled with an element 25 of an electric powertrain of the vehicle. The third heat exchanger 3 thus cools the element 25 of the electric powertrain.

[0113] According to the illustrated example in Figures 3 and 4, the heat transfer fluid F3 is a heat transfer fluid of a heat transfer fluid circuit 40, the element 25 of the vehicle's electric drive chain being configured to exchange heat with the heat transfer fluid of the circuit 40. A circulation pump, not shown, circulates the heat transfer fluid in circuit 40. The circulation pump is, for example, an electrically driven pump. The heat transfer fluid F3 is, for example, a mixture of water and glycol.

[0114] Element 25 of the vehicle's electric drive chain includes, for example, an electrical energy storage battery. Alternatively, or in addition, element 25 of the vehicle's electric drive chain includes an electric vehicle traction motor. Alternatively, or as a complement, element 25 of the vehicle's electric drive chain includes an electronic control unit for the vehicle's electric traction motor.

[0115] According to an unshown embodiment, the second heat exchanger 2 is thermally coupled with an element 25 of an electric powertrain of the vehicle. According to this embodiment, the third heat exchanger 3 is configured to exchange heat with a heat transfer fluid circulating in a heat transfer fluid circuit, and the heat transfer fluid circuit includes a heat exchanger configured to exchange heat with the interior airflow Fi. In other words, the role of the second exchanger 2 and the third exchanger 3 are reversed in this unrepresented variant.

[0116] Fig. 5 illustrates the operation of the thermal conditioning system 100 of Fig. 1. In this figure, the portions of circuit 10 in which a flow of refrigerant circulates are shown as solid lines, thicker than in figures 1, 3, and 4. The different Arrows indicate the direction of refrigerant flow in the different portions of the refrigerant circuit 10.

[0117] In steady state, the time variation of the mass of refrigerant in a heat exchanger is zero, and the flow rate of refrigerant downstream of a heat exchanger is equal to the flow rate of refrigerant upstream of this 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. Figure 5 corresponds to steady-state operation.

[0118] Fig. 5 schematically illustrates a method of operation of a thermal conditioning system 100 as described above, in a first mode of operation. In this operating mode: - a first flow Qrl of refrigerant fluid circulates in the first compression device 7 where it passes under high pressure, - a second flow Qr2 of refrigerant fluid circulates in the second compression device 8 where it passes under high pressure, The first flow Qrl and the second flow Qr2 join together and form a third flow Qr3 of high-pressure refrigerant fluid. The third flow Qr3 circulates successively in the first exchanger 1 where it releases heat, in the first heat exchange section 5 of the internal exchanger 4, in the second heat exchange section 6 of the internal exchanger 4, and divides into: - a fourth flow rate Qr4 of refrigerant circulating in the bypass branch B, and - a fifth flow Qr5 of refrigerant circulating in the main loop A. The fourth flow Qr4 of refrigerant circulates successively in the second expansion valve 22 where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the third exchanger 3 where it evaporates, in the first heat exchange section 5 of the internal exchanger 4, then returns to the inlet 8a of the second compressor 8. The fifth flow Qr5 of refrigerant circulates successively in the first expansion valve 21 where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, in the second exchanger 2 where it evaporates, in the second heat exchange section 6 of the internal exchanger 4, then returns to the inlet 7a of the first compressor 7.

[0119] In steady state, the fourth flow rate Qr4 and the second flow rate Qr2 are equal. Similarly, the fifth flow rate Qr5 and the first flow rate Qrl are equal.

[0120] The pressure of the refrigerant in the third heat exchanger 3 is greater than the pressure of the refrigerant in the second heat exchanger 2. The evaporation temperature of the refrigerant in the third heat exchanger 3 is therefore higher than the evaporation temperature in the second heat exchanger 2.

[0121] The high-pressure refrigerant from the first heat exchanger 1, circulating in the high-pressure part of the first heat exchange section 5 of the internal heat exchanger 4, therefore exchanges heat with the intermediate-pressure refrigerant, i.e., the hottest of the refrigerant from the second heat exchanger 2 and the refrigerant from the third heat exchanger 3. The high-pressure refrigerant circulating in the high-pressure part of the second heat exchange section 6, after having released heat in the first heat exchange section 5 and thus having cooled down, exchanges heat with the low-pressure refrigerant, i.e., the least hot of the refrigerant from the second heat exchanger 2 and the refrigerant from the third heat exchanger 3. The hottest high-pressure refrigerant thus exchanges heat with the hottest expanded refrigerant, while the coolest high-pressure refrigerant exchanges heat with the coolest expanded refrigerant.

[0122] This configuration is favorable to overall thermal efficiency.

[0123] The value of the so-called high pressure is for example between 19 bar and 36 bar. The value of the pressure called intermediate pressure is, for example, between 5 bar and 9 bar. The value of the so-called low pressure is, for example, between 2 bar and 5 bar. These values ​​correspond to the use of R290 as the refrigerant circulating in circuit 10. The ranges of values ​​differ when a different refrigerant is used.

[0124] The second flow Qr2 of high-pressure refrigerant, discharged by the second compressor 8, joins the first flow Qrl of high-pressure refrigerant, discharged by the first compressor 7, at the second connection point 12. The two combined flow rates form the third flow rate Qr3, which circulates in the main loop A, successively in the first heat exchanger 1, in the accumulation device 9, in the first heat exchange compartment 5A of the first heat exchange section 5 of the internal heat exchanger 4, and in the first heat exchange compartment 6A of the second heat exchange section 6 of the internal exchanger 4.

[0125] The third flow Qr3 of high-pressure refrigerant is divided at the first connection point 11 into a fourth flow Qr4 of refrigerant circulating in the bypass branch B towards the second expansion valve 22, and into a fifth flow Qr5 of refrigerant circulating in the main loop A towards the first expansion valve 21.

[0126] The fourth flow Qr4 of refrigerant circulates successively through the second expansion valve 22 where it passes through an intermediate pressure lower than the high pressure. The refrigerant at intermediate pressure circulates through the third heat exchanger 3 where it evaporates, then through the second heat exchange compartment 5B of the first heat exchange section 5 of the internal heat exchanger 4, and then returns to the inlet 8a of the second compressor 8. The second compressor 8 again brings the refrigerant from the intermediate pressure to the high pressure. The fifth flow Qr5 of refrigerant circulates successively through the first expansion valve 21 where it drops to a low pressure lower than the intermediate pressure. The low-pressure refrigerant circulates through the second heat exchanger 2 where it evaporates, then through the second heat exchange compartment 6B of the second heat exchange section 6 of the internal heat exchanger 4, and finally returns to the inlet 7a of the first compressor 7. The first compressor 7 again increases the refrigerant pressure from low to high.

[0127] According to other embodiments, not shown, the second exchanger 2 and the third exchanger 3 may have a different function. For example, the second heat exchanger 2 can be coupled with a first airflow from inside the vehicle's passenger compartment, and the third heat exchanger 3 can be coupled with a second airflow from inside the passenger compartment, the second airflow being directed to another area of ​​the passenger compartment. For example, the first airflow can supply the front part of the passenger compartment, and the second airflow can supply the rear part of the passenger compartment. In another example, the second interchanger 2 can be coupled to the first element of the vehicle's electric powertrain, and the third interchanger 3 is coupled to the second element of the vehicle's electric powertrain. Other applications are, of course, possible.

Claims

1. Demands 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 refrigerant circulation loop (A) comprising successively, according to a direction of refrigerant circulation: — a first compressor (7), — a first heat exchanger (1) thermally coupled with a first airflow (Fl), — a first regulator (21), — a second heat exchanger (2) thermally coupled with a second airflow (F2), - a branch (B) connecting a first connection point (11) located on the main loop (A) downstream of the first heat exchanger (1) and upstream of the first expansion valve (21) to a second connection point (12) located on the main loop (A) downstream of the first compressor (7) and upstream of the first heat exchanger (1), the branch (B) comprising successively: — a second regulator (22), — a third heat exchanger (3) thermally coupled with a heat transfer fluid (F3), — a second compressor (8), - an internal heat exchanger (4) comprising: — a first heat exchange section (5) arranged jointly on the main loop (A) and on the bypass branch (B), configured to allow heat exchange between the refrigerant circulating between the first exchanger (1) and the first connection point (11) and the refrigerant circulating between the third exchanger (3) and an inlet (8a) of the second compressor (8), — a second heat exchange section (6) arranged on the main loop (A), configured to allow heat exchange between the refrigerant circulating between the first heat exchange section (5) and the refrigerant circulating between the second exchanger (2) and an inlet (7a) of the first compressor (7).

2. Thermal conditioning system (100) according to claim 1, wherein the first heat exchange section (5) and the second heat exchange section (6) are integrated into a common body (15).

3. Thermal conditioning system (100) according to claim 1 or 2, wherein the first heat exchange section (5) and the second heat exchange section (6) form a non-removable assembly.

4. Thermal conditioning system (100) according to any one of the preceding claims, wherein the internal exchanger (4) is a plate exchanger.

5. Thermal conditioning system (100) according to any one of the preceding claims in combination with claim 2, wherein the body (15) of the internal exchanger (4) is formed by a plurality of plates stacked along a stacking direction, a space separating two consecutive plates defining a refrigerant circulation channel, and wherein: a refrigerant circulation channel of the first heat exchange section (5) is intercalated, along the stacking direction, between two consecutive refrigerant circulation channels of the second heat exchange section (6).

6. Thermal conditioning system (100) according to any one of the preceding claims, wherein: - the first heat exchange section (5) of the internal exchanger (4) is a counter-current exchanger, and - the second heat exchange section (6) of the internal exchanger (4) is a counter-current exchanger.

7. Thermal conditioning system (100) according to any one of claims 1 to 6, wherein the main loop (A) includes an accumulation device (9) disposed downstream of the first exchanger (1) and upstream of the first heat exchange section (5) of the internal exchanger (4).

8. Thermal conditioning system (100) according to any one of claims 1 to 6, wherein the main loop (A) comprises a first accumulation device (9') disposed downstream of the second exchanger (2) and upstream of the second heat exchange section (6) of the internal exchanger (4), and in which the bypass branch (B) includes a second accumulation device (9”) disposed downstream of the third exchanger (3) and upstream of the first heat exchange section (5) of the internal exchanger (4).

9. Thermal conditioning system (100) according to any one of the preceding claims, wherein: - the first airflow (Fl) is an outside airflow (Fe) to a vehicle cabin, - the second airflow (F2) is an inside airflow (Fi) to a vehicle cabin, and - the third heat exchanger (3) is thermally coupled with an element (25) of an electric powertrain of the vehicle.

10. A method of operating a thermal conditioning system (100) according to any one of the preceding claims, in a first mode of operation in which: - a first flow (Qrl) of refrigerant circulates in the first compression device (7) where it passes through a high pressure, - a second flow (Qr2) of refrigerant circulates in the second compression device (8) where it passes through a high pressure, the first flow (Qrl) and the second flow (Qr2) join together and form a third flow (Qr3) of refrigerant at high pressure, the third flow (Qr3) circulates successively in the first heat exchanger (1) where it releases heat, in the first heat exchange section (5) of the internal heat exchanger (4), in the second heat exchange section (6) of the internal heat exchanger (4), and divides into: — a fourth flow (Qr4) of refrigerant circulating in the bypass branch (B),and — a fifth flow rate (Qr5) of refrigerant circulating in the main loop (A), — the fourth flow rate (Qr4) of refrigerant circulates successively in the second expansion valve (22) where it undergoes expansion and passes to an intermediate pressure lower than the high pressure, in the third heat exchanger (3) where it evaporates, in the, first heat exchange section (5) of the internal exchanger (4), then returns to the inlet (8a) of the second compressor (8), - the fifth flow (Qr5) of refrigerant circulates successively in the first expansion valve (21) where it undergoes expansion and passes to a low pressure lower than the intermediate pressure, in the second exchanger (2) where it evaporates, in the second heat exchange section (6) of the internal exchanger (4), then returns to the inlet (7a) of the first compressor (7).

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