EP4392276A1 - Thermal conditioning system - Google Patents

Abstract

The invention relates to a thermal conditioning system (100) having a refrigerant fluid circuit (1) which comprises: • - a main loop (A) comprising, successively: • -- a first compression device (1), • -- a second compression device (2), • -- a first heat exchanger (31) designed to exchange heat with a heat-transfer fluid (F1), • -- a first pressure-reducing valve (41), • -- a first evaporator (3), • - a first bypass branch (B) connecting a first coupling point (11) located on the main loop (A) between the first exchanger (31) and the first pressure-reducing valve (41) at a second coupling point (12) located on the main loop (A) between the first compression device (1) and the second compression device (2), the first bypass branch (B) comprising a second pressure-reducing valve (42) and a second evaporator (4), • - an internal heat exchanger (5) located jointly on the main loop (A) between the first coupling point (11) and the first pressure-reducing valve (41), and on the first bypass branch (B) between the second pressure-reducing valve (42) and the second evaporator (4).

Description

THERMAL CONDITIONING SYSTEM

Technical area

[1] The present invention relates to the field of thermal conditioning systems. Such systems can for example be fitted to motor vehicles. These systems ensure thermal regulation of various parts of the vehicle, such as the passenger compartment or an electrical energy storage battery, for example, when the vehicle is electrically powered. Heat exchanges are mainly managed by the compression and expansion of a refrigerant fluid circulating in a circuit in which several heat exchangers are arranged.

Prior technique

[2] It is well known, in the case of an electric propulsion vehicle, to cool one or more elements of the electric traction chain. In particular, it is desirable to cool the electrical energy storage battery in order to keep it within a temperature range favorable to its operation. Such cooling is ensured by means of a heat exchanger operating as a refrigerant fluid evaporator, and thermally coupled with the battery. The flow of refrigerant required is generally provided by a single compressor. The desire to reduce the charging time of the battery leads to the use of increasingly high electrical charging powers, which also increases the need for cooling power to be provided. A single compressor may become insufficient to provide adequate refrigerant flow. Applications using two separate compressors have thus been developed. One of them is described in patent FR3075705.

[3] It is also conventional to carry out the heating of the passenger compartment of the vehicle by condensing the high-pressure refrigerant fluid in a heat exchanger traversed by a flow of air supplying the passenger compartment. An additional electric heating device is frequently used in addition, in order to accelerate the heating in a cold environment, in particular when the ambient temperature is negative. Such an additional heating device has the drawbacks of increasing the cost, size and weight of the system. [4] There is therefore a need for a thermal conditioning system capable of providing higher battery cooling power than that of existing systems, while also being capable of ensuring the heating of the passenger compartment of the vehicle with low response time without using an additional heater. It is also desirable to have operating modes that make it possible to reduce the energy consumption of the system, by adapting to the operating conditions the recovery of heat from the various available heat sources.

Summary

[5] To this end, the present invention proposes a thermal conditioning system comprising a refrigerant circuit configured to circulate a refrigerant fluid, the refrigerant circuit comprising:

A main loop comprising successively, depending on the direction of circulation of the refrigerant fluid:

-- a first compression device ,

-- a second compression device ,

-- a first heat exchanger configured to exchange heat with a first heat transfer fluid,

-- a first regulator ,

-- a first evaporator ,

A first bypass branch connecting a first connection point arranged on the main loop downstream of the first heat exchanger and upstream of the first expansion valve to a second connection point arranged on the main loop downstream of the first compression device and upstream of the second compression device, the first bypass branch successively comprising a second expansion valve and a second evaporator, a first internal exchanger arranged jointly on the main loop downstream of the first connection point and upstream of the first expansion valve, and on the first branch bypass downstream of the second expansion valve and upstream of the second evaporator.

[6] This circuit architecture, combining two compression devices and at least two evaporators, makes it possible to provide a maximum power of high cooling overall allowing good energy efficiency over a wide operating power range.

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

[8] The thermal conditioning system is configured to operate at least in a mode in which the refrigerant fluid circulating in the first bypass branch is in the state of superheated vapor at the outlet of the first internal exchanger.

[9] The second evaporator is thus rendered inactive, that is to say that even if a flow of refrigerant fluid passes through the second evaporator, this flow of refrigerant fluid does not undergo heat transfer, or at most a negligible heat transfer compared to the nominal capacity of the second evaporator. This operating mode makes it possible to optimize the operation of the thermal conditioning system under certain operating conditions. For example, this operating mode makes it possible to reduce the enthalpy at the inlet of the first evaporator and makes it possible to increase the heat exchange in the first evaporator.

[10] The second expansion valve is controlled by a measurement at the outlet of the first internal exchanger of overheating of the refrigerant fluid circulating in the first bypass branch.

[11] According to one embodiment, the thermal conditioning system is a thermal conditioning system of a motor vehicle.

[12] According to one embodiment, the first heat transfer fluid is a flow of air inside a passenger compartment of a motor vehicle.

[13] Alternatively, the first heat transfer fluid is a flow of air outside the passenger compartment of a motor vehicle.

[14] According to an exemplary embodiment, the first evaporator is thermally coupled with a first element of a traction chain of a motor vehicle. [15] The first element of the electric traction chain comprises for example an electric traction motor of the vehicle.

[16] The first element of the vehicle's electric traction chain may also include an electronic module for controlling an electric traction motor of the vehicle.

[17] According to a possible implementation, the first evaporator is thermally coupled with the first element via a heat transfer liquid circulating in a first secondary loop of heat transfer liquid.

[18] According to another possible implementation, the first evaporator is in contact with the first element.

[19] According to an exemplary embodiment, the second evaporator is thermally coupled with a second element of a traction chain of a motor vehicle.

[20] For example, the second element of the vehicle's electric powertrain includes an electrical energy storage battery.

[21] The battery can supply the energy needed to drive the vehicle.

[22] According to an exemplary implementation of the invention, the second evaporator is thermally coupled with the second element via a heat transfer liquid circulating in a second secondary loop of heat transfer liquid.

[23] According to a variant embodiment, the second evaporator is in contact with the second element.

[24] The second secondary loop is isolated from the first secondary coolant loop.

[25] According to one embodiment, the thermal conditioning system comprises a second bypass branch connecting a third connection point arranged on the main loop downstream of the first compression device and upstream of the second connection point to a fourth point connection arranged on the main loop downstream of the second compression device and upstream of the first heat exchanger. [26] According to one embodiment, the thermal conditioning system comprises a third bypass branch connecting a fifth connection point arranged on the second bypass branch to a sixth connection point arranged on the main loop downstream of the first heat exchanger. heat and upstream of the first connection point.

[27] According to one embodiment, the refrigerant circuit comprises a first three-way valve arranged jointly on the main loop and on the first bypass branch.

[28] According to one embodiment, the refrigerant circuit comprises a second three-way valve arranged jointly on the second bypass branch and on the third bypass branch.

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

[30] According to one embodiment of the thermal conditioning system, the main loop successively comprises a third expansion valve and second heat exchanger configured to exchange heat with a second heat transfer fluid.

[31] The second heat transfer fluid is a flow of air outside the passenger compartment of a motor vehicle.

[32] According to one embodiment, the thermal conditioning system comprises a third bypass branch connecting a fifth connection point arranged on the second bypass branch to a sixth connection point arranged on the main loop between the third regulator and the second heat exchanger.

[33] According to one embodiment, the thermal conditioning system comprises a fourth bypass branch connecting a seventh connection point arranged on the main loop downstream of the fourth connection point and upstream of the sixth connection point to an eighth point connection arranged on the main loop downstream of the second heat exchanger and upstream of the first connection point. [34] The thermal conditioning system may include a fifth bypass branch connecting a ninth connection point arranged on the first bypass branch downstream of the second evaporator to a tenth connection point arranged on the main loop downstream of the first internal exchanger and upstream of the first regulator.

[35] The thermal conditioning system may also include a sixth bypass branch connecting an eleventh connection point arranged on the main loop downstream of the tenth connection point and upstream of the first regulator to a twelfth connection point arranged on the loop main downstream of the first evaporator and upstream of the first compression device, the sixth bypass branch successively comprising a fourth expander and a third heat exchanger configured to exchange heat with an air flow inside a passenger compartment of a motor vehicle.

[36] The thermal conditioning system may further comprise a seventh branch branch connecting a thirteenth connection point arranged on the main loop downstream of the second heat exchanger and upstream of the eighth connection point to a fourteenth connection point arranged on the main loop downstream of the twelfth connection point and upstream of the first compression device.

[37] The fourteenth connection point can be confused with the twelfth connection point.

[38] According to one embodiment, the main loop comprises a fourth heat exchanger arranged downstream of the second heat exchanger and upstream of the first connection point, the fourth heat exchanger being configured to exchange heat with a flow outside air to a vehicle cabin.

[39] Alternatively or additionally, the thermal conditioning system comprises a two-fluid heat exchanger disposed jointly on the main refrigerant loop downstream of the second heat exchanger and upstream of the eighth connection point, and on an auxiliary loop of liquid coolant in such a way as to allow heat exchange between the refrigerant fluid and the coolant liquid.

[40] The two-fluid heat exchanger is arranged upstream of the fourth heat exchanger in the direction of circulation of the refrigerant fluid.

[41] The auxiliary coolant loop includes a fifth heat exchanger configured to exchange heat with a flow of air outside a passenger compartment of the vehicle.

[42] Preferably, the fourth heat exchanger is arranged upstream of the fifth heat exchanger in a flow direction of the outside air flow.

[43] Preferably again, the fifth heat exchanger is arranged upstream of the second heat exchanger in a flow direction of the outside air flow.

[44] According to an exemplary implementation, the main loop comprises a coolant accumulation device arranged downstream of the fourteenth connection point and upstream of the first compression device.

[45] As a variant, the main loop comprises a refrigerant fluid accumulation device arranged downstream of the eighth connection point and upstream of the first connection point.

[46] According to one embodiment, the main loop comprises a second internal exchanger arranged jointly on the main loop downstream of the refrigerant fluid accumulation device and upstream of the first compression device, and on the main loop downstream of the tenth connection point and upstream of the eleventh connection point.

[47] According to one embodiment, the refrigerant circuit comprises a third internal exchanger arranged jointly on the main loop downstream of the first connection point and upstream of the first internal exchanger, and on the main loop downstream of the second point connection and upstream of the second compression device.

[48] According to one embodiment, the thermal conditioning system further comprises an eighth bypass branch connecting a fifteenth point of connection arranged on the main loop downstream of the fourteenth connection point and upstream of the first compression device to a sixteenth connection point arranged on the first branch branch downstream of the ninth connection point and upstream of the second connection point.

[49] According to one embodiment, the main loop A comprises a first shut-off valve arranged between the first connection point and the tenth connection point.

[50] Similarly, the fourth branch branch has a second shut-off valve.

[51] Similarly, the seventh branch branch has a third shut-off valve.

[52] According to one embodiment, the first bypass branch B comprises a first non-return valve configured to block circulation of the refrigerant fluid from the ninth connection point to the second evaporator.

[53] Similarly, the fifth bypass branch includes a second non-return valve configured to block circulation of the refrigerant fluid from the tenth connection point to the ninth connection point.

[54] The sixth bypass branch also includes a third non-return valve configured to block circulation of the refrigerant fluid from the twelfth connection point to the third heat exchanger.

[55] The seventh bypass branch also includes a fourth check valve configured to block a flow of refrigerant from the fourteenth connection point to the thirteenth connection point.

[56] According to one implementation of the invention, the first internal exchanger is a plate exchanger.

[57] This type of exchanger offers good performance in terms of heat exchange, in particular for the thermal power range corresponding to an internal exchanger. In addition, this type of exchanger is inexpensive to manufacture and of a compact form allowing easy integration. [58] According to a preferred embodiment, the first compression device and the second compression device are two independent compressors.

[59] According to another embodiment, the first compression device and the second compression device are respectively a first compression stage and a second compression stage of the same compressor.

[60] The compressor comprises a body containing the first compression stage and the second compression stage.

[61] The compressor body includes the second branch branch.

[62] The body of the compressor includes a portion of the main loop extending between the inlet of the first compression device and the fourth connection point.

[63] The compressor body includes the second connection point. Likewise, the compressor body includes the fifth connection point.

[64] According to one embodiment, the thermal conditioning system comprises a first casing defining a receiving volume. A main loop portion extending between the third connection point and the second connection point is contained inside the first housing. A portion of the second branch branch comprising the fifth connection point is also contained inside the first casing. A portion of the third branch branch including the fifth connection point is also contained within the first housing.

[65] The first housing has inlets / outlets of refrigerant, each inlet / outlet allowing a fluid connection with a portion of the refrigerant circuit.

[66] Alternatively, or additionally, the thermal conditioning system comprises a second housing defining a receiving volume. The fourth branch branch, the third regulator and a main loop portion extending between the third regulator and the seventh connection point are contained inside the second casing. Similarly, the second regulator, the first shut-off valve, the internal exchanger and a portion main loop extending between the eighth connection point and the internal exchanger are contained inside the second housing.

[67] The second housing has coolant inlets/outlets, each inlet/outlet allowing fluid connection with a portion of the coolant circuit.

[68] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called second evaporator inactivation mode, in which:

- the refrigerant is divided at the first connection point into a first flow circulating in the first bypass branch and a second flow circulating in the main loop,

- the first flow circulates successively in the second regulator where it undergoes expansion, in the first internal exchanger, in the second evaporator,

- the second flow circulates in the first internal exchanger, and in which the first flow is in the state of superheated steam at the outlet of the first internal exchanger.

[69] Thus, the second evaporator is supplied with superheated steam. The heat exchange in the second evaporator is negligible under these conditions. This mode of operation makes it possible to minimize the enthalpy of the refrigerant fluid at the outlet of the heat exchange section of the internal exchanger arranged on the main loop, without carrying out any heat exchange in the second evaporator. The cooling capacity of the system is then maximized, and can be distributed between the first evaporator and the third heat exchanger.

[70] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called passenger compartment heating mode with energy recovery, in which:

- a first flow of low-pressure refrigerant circulates in the first compression device where it passes to an intermediate pressure,

- a second flow of refrigerant fluid at intermediate pressure circulates in the first bypass branch and joins the first flow, forming a total flow of refrigerant fluid at intermediate pressure,

- the total flow of refrigerant at intermediate pressure circulates in the second compression device where it passes at high pressure, in the first heat exchanger where it gives up heat to the internal air flow, in the fourth bypass branch,

- is divided into a third flow circulating in the first bypass branch and a fourth flow circulating in the main loop, the third flow circulates successively in the second regulator where it passes at intermediate pressure, in the first internal exchanger, in the second evaporator where it absorbs heat, and joins the first flow of refrigerant fluid circulating in the main loop at the outlet of the first compression device,

- the fourth flow circulates in the first internal exchanger, in the first regulator where it passes at low pressure, in the first evaporator where it absorbs heat, and joins the first compression device.

[71] This mode of operation ensures that the passenger compartment is heated by dissipating the heat of the refrigerant fluid circulating successively in the two compression devices into the interior air flow. The thermodynamic cycle is completed by absorbing heat at the level of the first evaporator and the second evaporator. This heat is recovered respectively from the first element and from the second element. The distribution between the heat absorbed at the level of the first evaporator and the heat absorbed at the level of the second evaporator is achieved by adjusting the speed of rotation of the first compression device and of the second compression device. This mode makes it possible to obtain a high heating power without having to use an additional heating device.

[72] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called cabin cooling and powertrain cooling mode, in which:

- a first flow of low-pressure refrigerant circulates in the first compression device where it passes to intermediate pressure, then circulates successively in the second bypass branch,

- a second flow of refrigerant circulates successively in the second compression device where it passes at intermediate pressure and in the second bypass branch, and joins the first flow, forming a total flow of refrigerant fluid at intermediate pressure,

- the total flow of refrigerant fluid at intermediate pressure circulates successively in the third bypass branch, in the second heat exchanger where it yields heat to the external air flow, is divided into a third flow circulating in the first branch of bypass and a fourth flow circulating in the main loop, the third flow circulates successively in the second expansion valve where it undergoes expansion, in the second heat exchange section of the first internal exchanger, in the second evaporator where it absorbs heat, the fourth flow circulates successively in the first heat exchange section of the first internal exchanger, in the fourth expansion valve where it passes at low pressure, in the third heat exchanger where it absorbs heat from the internal air flow.

[73] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called battery heating and energy recovery mode in which:

- a flow rate the low pressure refrigerant fluid circulates successively in the first compression device where it passes at an intermediate pressure, in the second compression device where it passes at high pressure, in the first heat exchanger, in the fourth branch of bypass, in the first bypass branch, in the second expansion valve, in the second evaporator where it releases heat, in the fifth bypass branch, in the first expansion valve where it passes to low pressure, in the first evaporator where it absorbs heat, and joins the first compression device.

[74] Heating of the second element of the traction chain can thus be ensured. Part of the heat transferred to the second element comes from the heat taken from the first element of the traction chain. For example, the battery can be heated while recovering the heat given off by the electronic module, which minimizes the energy expended.

[75] As a variant, the flow of refrigerant fluid at low pressure circulates successively in the first compression device where it passes to high pressure, in the second bypass branch, in the first heat exchanger. The rest of the route is the same. According to this variant of the so-called battery heating and energy recovery mode, only the first compression device operates. The second compression device does not work, and is bypassed by the high pressure refrigerant fluid.

[76] The invention also relates to a method of operating a thermal conditioning system as described above, in a so-called accelerated cooling mode, in which:

- a flow of low-pressure refrigerant fluid is divided between a first flow and a second flow,

- the first flow circulates in the first compression device where it passes to an intermediate pressure,

- the second flow circulates in the second compression device where it passes to an intermediate pressure, circulates in the second bypass branch and joins the first flow, forming a flow of refrigerant fluid at intermediate pressure, the flow circulates in the third branch of bypass, joins the main loop, circulates successively in the second heat exchanger where it yields heat to the external air flow, in the fourth expansion device where it passes to low pressure, in the third heat exchanger where it absorbs from the heat of the interior airflow.

Brief description of the drawings

[77] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

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

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

[80] [Fig. 3] is a schematic view of a thermal conditioning system according to a third embodiment of the invention, [81] [Fig. 4] is a schematic view of a thermal conditioning system according to a fourth embodiment of the invention,

[82] [Fig. 5] is a schematic view of a thermal conditioning system according to a fifth embodiment of the invention

[83] [Fig. 6] is a schematic view of the thermal conditioning system according to the first embodiment, operating according to a first mode of operation, said mode called inactivation of the second evaporator,

[84] [Fig. 7] is a schematic view of the thermal conditioning system according to the first embodiment, operating according to a second mode of operation, said so-called passenger compartment heating mode with energy recovery,

[85] [Fig. 8] is a schematic view of the thermal conditioning system according to the first embodiment, operating according to a third mode of operation, said mode of cabin cooling and powertrain cooling,

[86] [Fig. 9] is a schematic view of the thermal conditioning system according to the first embodiment, operating according to a fourth mode of operation, called battery heating mode and energy recovery,

[87] [Fig. 10] is a schematic view of the thermal conditioning system according to the fifth embodiment, operating according to an operating mode, called accelerated cooling mode,

[88] [Fig. 11] is a schematic view of a variant of the thermal conditioning system of Figure 1.

Description of embodiments

[89] To make the figures easier to read, the various elements are not necessarily shown to scale. In these figures, identical elements bear the same references. Certain elements or parameters can be indexed, that is to say designated for example by first element or second element, or else first parameter and second parameter, etc. This indexing is intended to differentiate between similar elements or parameters, but not identical. This indexing does not imply a priority of an element, or parameter compared to another and one can interchange the denominations.

[90] In the following description, the term "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 circulation, or course, 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 circulation, or travel, 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 successively passes through the first element, then the second element, without passing through the compression device. In other words, the refrigerant leaves the compression device, possibly crosses one or more elements, then crosses the first element, then the second element, then returns to the compression device, possibly after having crossed other elements.

[91] The term “a second element is placed between a first element and a third element” means that the shortest route to go from the first element to the third element passes through the second element.

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

[93] An electronic control unit, not shown in the figures, 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 issued by the occupants of the vehicle, such as for example the desired temperature inside the passenger compartment. The electronic control unit can also receive instructions coming from other electronic subsystems, such as for example the system for managing electrical energy storage batteries. The electronic control unit implements control laws allowing the piloting of the various actuators, in order to ensure the control of the thermal conditioning system 100 so as to ensure the instructions received. [94] Each of the expansion devices used can be an electronic expansion valve, a thermostatic expansion valve, or a calibrated orifice. In the case of an electronic expansion valve, the passage section allowing the refrigerant fluid to pass can be adjusted continuously between a closed position and a maximum open position. For this, the system control unit drives an electric motor which moves a movable shutter controlling the section of passage offered to the refrigerant fluid.

[95] The refrigerant circuit 10 forms a closed circuit in which the refrigerant can circulate. The refrigerant circuit 10 is sealed when the latter is in a nominal operating state, that is to say without any fault or leak. Each connection point of circuit 10 allows the coolant to pass through one or the other of the circuit portions joining at this connection point. The distribution of the refrigerant fluid between the portions of the circuit joining at a connection point is done by playing on the opening or closing of the stop valves, non-return valves or expansion devices included on each of the branches. In other words, each connection point is a means of redirecting the refrigerant fluid arriving at this connection point.

[96] Various shut-off valves and non-return valves thus make it possible to selectively direct the refrigerant fluid in the different branches of the refrigerant circuit, in order to ensure different modes of operation, as will be described later. For example, the second shut-off valve 52 is configured to selectively authorize or prohibit the passage of the refrigerant fluid in the fourth bypass branch E. A non-return valve is a passive device, that is to say that no electric control is not necessary. A shut-off valve is electrically controlled.

[97] The refrigerant used by the refrigerant circuit 10 is here a chemical fluid such as R1234yf. Other refrigerants can also be used instead, such as R134a, or R744.

[98] There is shown in Figure 1 a thermal conditioning system 100 according to a first embodiment. In the example illustrated, the thermal conditioning system 100 is a thermal conditioning system of a motor vehicle. [99] The thermal conditioning system 100 includes a refrigerant circuit 10 configured to circulate a refrigerant fluid, the refrigerant circuit 10 comprising:

A main loop A comprising successively, depending on the direction of circulation of the refrigerant fluid:

- a first compression device 1,

-- a second compression device 2,

- a first heat exchanger 31 configured to exchange heat with a first heat transfer fluid F1,

- a first regulator 41,

-- a first evaporator 3,

A first bypass branch B connecting a first connection point 11 disposed on the main loop A downstream of the first heat exchanger 31 and upstream of the first regulator 41 to a second connection point 12 disposed on the main loop A downstream of the first compression device 1 and upstream of the second compression device 2, the first bypass branch B successively comprising a second expansion valve 42 and a second evaporator 4, a first internal exchanger 5 arranged jointly on the main loop A downstream of the first connection point 1 1 and upstream of the first regulator 41, and on the first bypass branch B downstream of the second regulator 42 and upstream of the second evaporator 4.

[100] This circuit architecture makes it possible to provide a high maximum cooling power while allowing good energy efficiency over a wide operating power range.

[101] The thermal conditioning system 100 is configured to operate at least according to a mode in which the refrigerant fluid circulating in the first bypass branch B is in the state of superheated vapor at the outlet of the first internal exchanger 5. where the thermal conditioning system can selectively operate according to an operating mode in which the refrigerant fluid is superheated at the outlet of the first internal exchanger, and can selectively operate according to other operating modes in which the refrigerant leaving the first internal exchanger is not overheated.

[102] The second evaporator 4 is thus rendered inactive, that is to say that even if a flow of refrigerant fluid passes through the second evaporator 4, this flow of refrigerant fluid does not undergo heat transfer. This operating mode makes it possible to optimize the operation of the thermal conditioning system under certain operating conditions.

[103] The second expansion valve 42 is controlled by a measurement at the output of the first internal exchanger 5 of an overheating of the refrigerant fluid circulating in the first bypass branch B. The flow of refrigerant fluid through the second expansion valve 42 is controlled so so that the heat exchange in the first internal exchanger 5 makes it possible to obtain superheated steam at the outlet of the second heat exchange section 5b.

[104] The first heat transfer fluid F1 is here an interior air flow Fi to a passenger compartment of a motor vehicle.

[105] According to a variant not illustrated, the first heat transfer fluid F1 is a flow of air Fe outside the passenger compartment of a motor vehicle.

[106] Interior air flow Fi means an air flow intended for the passenger compartment of the motor vehicle. This indoor air flow Fi can circulate in a heating, ventilation and/or air conditioning installation, frequently referred to by the English term “HVAC”, for “Heating, Ventilating and Air Conditioning”. This installation has not been shown in the various figures. A first motor-fan unit, also not shown, is placed in the heating, ventilation and/or air conditioning installation in order to increase, if necessary, the flow rate of the interior air flow Fi.

[107] By outside air flow Fe is meant an air flow which is not intended for the passenger compartment of the vehicle. In other words, this air flow Fe remains outside the passenger compartment of the vehicle. A second motor-fan unit, also not shown, can be activated in order to increase the flow rate of the outside air flow Fe if necessary. The air flow provided by the first as well as by the second motor-fan unit can be adjusted in real time according to exchange needs thermal, for example by the electronic control unit of the thermal conditioning system 100.

[108] The first evaporator 3 is configured to operate selectively as a condenser in particular cases of operation of the thermal conditioning system. Similarly, the second evaporator 4 is configured to operate selectively as a condenser. In other words, in particular operating modes, condensation of the refrigerant fluid can occur in the first evaporator 3. The same is true for the second evaporator 4. According to the example illustrated, the first evaporator 3 is thermally coupled with a first element 25 of a traction chain of a motor vehicle. In other words, the first evaporator 3 can exchange heat with the first element 25 of a traction chain of a motor vehicle.

[109] The first element 25 of the electric traction chain comprises in the example illustrated an electric traction motor of the vehicle. The first element 25 of the electric traction chain of the vehicle can also comprise an electronic module for controlling an electric traction motor of the vehicle. This electronic control module is called an inverter. The first element 25 can also comprise an electrical energy storage battery.

[110] The first evaporator 3 is here thermally coupled with the first element 25 via a heat transfer liquid circulating in a first secondary loop 7 of heat transfer liquid. The heat transfer liquid can be a mixture of water and glycol.

[111] The first element 25 of the electric traction chain of the vehicle is configured to exchange heat with the first evaporator 3 via a heat transfer liquid circulating in a first secondary loop 7 of heat transfer liquid. The thermal coupling between the first evaporator 3 and the first element 25 is said to be indirect.

[112] According to a variant not shown, the first evaporator 3 is in contact with the first element 25. A wall of the first evaporator 3 is in contact with a wall of the first element 25. A paste aimed at improving the heat transfer between the two walls can be arranged between these two walls. This paste avoids the presence of a layer of air between the two walls, which would limit heat transfer. The thermal coupling is thus said to be direct.

[113] The second evaporator 4 is here thermally coupled with a second element 30 of a traction chain of a motor vehicle. In other words, the second evaporator 4 can exchange heat with the second element 30 of a traction chain of the motor vehicle.

[114] The second element 30 of the vehicle's electric traction chain includes an electrical energy storage battery. The battery can provide the energy needed to drive the vehicle. The battery voltage can be between 400 volts and 800 volts. The battery coupled to the second evaporator 4 can be the same battery as that coupled to the first evaporator 3.

[115] The second evaporator 4 is thermally coupled with the second element 30 via a heat transfer liquid circulating in a second secondary loop 8 of heat transfer liquid. The heat transfer liquid of the second secondary loop 8 can for example be a mixture of water and glycol.

[116] The second element 30 of the vehicle's electric powertrain is configured to exchange heat with the second evaporator 4 via a heat-transfer liquid circulating in a second secondary loop 8 of heat-transfer liquid. The thermal coupling is said to be indirect.

[117] According to a variant not shown, the second evaporator 4 is in contact with the second element 30. A wall of the second evaporator 4 is in contact with a wall of the second element 30. A paste aimed at improving the heat exchange between the two walls can be arranged between the two walls. The thermal coupling is said to be direct.

[118] The second secondary loop 8 is here isolated from the first secondary loop 7 of coolant. In other words, the heat transfer liquid of the second secondary loop 8 cannot mix with the heat transfer liquid of the first secondary loop 7.

[119] The first internal heat exchanger 5 comprises a first heat exchange section 5a arranged on the main loop A and a second heat exchange section 5b arranged on the first bypass branch B. The first internal heat exchanger 5 is configured to allow heat exchange between the refrigerant fluid in the first heat exchange section 5a and the refrigerant fluid in the second heat exchange section 5b. The refrigerant circulating at high pressure in the main loop A can thus transfer heat to the refrigerant circulating at a lower pressure in the first bypass branch B, after expansion in the second expansion valve 42.

[120] The first internal exchanger 5 is here a plate exchanger. The first internal exchanger 5 thus offers good performance in terms of heat exchange, while being inexpensive to manufacture and compact.

[121] In the embodiments corresponding to the figures, the first compression device 1 and the second compression device 2 are two independent compressors. The first compressor 1 and the second compressor 2 are controlled independently by the electronic control unit of the thermal conditioning system 100. The rotation speed of the first compressor 1 and the rotation speed of the second compressor 2 can be different and vary independently, allowing for different bit rates and compression ratios. The first compression device 1 is here an electric compressor, that is to say a compressor whose moving parts are driven by an electric motor. The first compression device 1 comprises a suction side of the low pressure refrigerant fluid, also called inlet 1 a of the compression device 1, and a discharge side of the refrigerant fluid at a higher pressure, also called outlet 1 b of the first compression device. squeeze 1 . The internal moving parts of the first compression device 1 cause the refrigerant fluid to pass from a low pressure on the inlet side 1a to a higher pressure on the outlet side 1b. The second compression device 2 can operate in the same way as the first compression device 1. The second compression device 2 comprises an input 2a and an output 2b. The two compression devices 1, 2 are not necessarily identical. In particular, their cylinder capacity may be different.

[122] According to the example illustrated, the thermal conditioning system comprises a second bypass branch C connecting a third connection point 13 disposed on the main loop A downstream of the first compression device 1 and upstream from the second connection point 12 to a fourth connection point 14 arranged on the main loop A downstream from the second compression device 2 and upstream from the first heat exchanger 31. The second bypass branch C is a branch bypass of the second compression device 2. In other words, the refrigerant fluid leaving the first compression device 1 can join the main loop A downstream of the second compression device 2 without passing through the second compression device 2.

[123] According to the example shown, the thermal conditioning system comprises a third bypass branch D connecting a fifth connection point 15 arranged on the second bypass branch C to a sixth connection point 16 arranged on the main loop A in downstream of the first heat exchanger 31 and upstream of the first connection point 11. The third bypass branch D is a bypass branch of the second compression device 2 and of the first heat exchanger 31 . In other words, the refrigerant fluid leaving the first compression device 1 can join the main loop A downstream of the first heat exchanger 31 without passing through the second compression device 2 or through the first heat exchanger 31 .

[124] According to an embodiment not illustrated, the first compression device 1 and the second compression device 2 are respectively a first compression stage and a second compression stage of the same compressor. The rotational speed of the first compression stage and the rotational speed of the second compression stage are linked. The compressor includes a body containing the first compression stage and the second compression stage. The body of the compressor comprises the second bypass branch C. The body of the compressor comprises a portion of main loop A extending between the inlet 1a of the first compression device 1 and the fourth connection point 14. The body of the compressor includes the second connection point 12. Likewise, the compressor body includes the fifth connection point 15.

[125] According to the first embodiment, illustrated in Figure 1, the refrigerant circuit 10 comprises a first three-way valve 54 disposed jointly on the main loop A and on the first bypass branch B. The second connection point 12 is part of the first three-way valve 54. This three-way valve makes it possible to selectively establish the following connections: the three ways communicate with each other, or each channel is isolated from the other two channels, or two of the three channels communicate with each other while the third channel is isolated from these two other channels. Other types of valves can be used to make the same fluidic connections. It is thus possible to use three separate stop valves 54a, 54b, 54c rather than a three-way valve 54. This alternative configuration is illustrated in the variant of FIG. 11.

[126] According to this first embodiment, the refrigerant circuit 10 comprises a second three-way valve 55 disposed jointly on the second bypass branch C and on the third bypass branch D. The fifth connection point 15 is part of the second three-way valve 55. As before, this three-way valve makes it possible to selectively establish the following connections: the three channels communicate with each other, or each channel is isolated from the other two channels, or two of the three channels communicate with each other while that the third channel is isolated from these two other channels. As before, it is also possible to use three separate shut-off valves 55a, 55b, 55c rather than the three-way valve 55. This alternative configuration corresponds to the variant of FIG. 11.

[127] According to a variant not shown, the fifth connection point 15 can be confused with the third connection point 13.

[128] In the example shown, the main loop A successively includes a third expansion valve 43 and a second heat exchanger 32 configured to exchange heat with a second heat transfer fluid F2. The second heat transfer fluid F2 is here a flow of air outside Fe in the passenger compartment of a motor vehicle.

[129] The first heat exchanger 31 may not be present in the thermal conditioning system 100. In this case, the second heat exchanger 32 is present without there being a first heat exchanger. In this case, the main loop A does not include any heat exchanger between the outlet 2b of the second expansion device and the seventh connection point 17. [130] The third regulator 43 is arranged downstream of the fourth connection point 14. The third regulator 43 is arranged downstream of the first heat exchanger 31 .

[131] The third branch D connects a fifth connection point 15 arranged on the second branch C to a sixth connection point 16 arranged on the main loop A between the third expansion valve 43 and the second heat exchanger 32.

[132] According to the embodiments illustrated in the various figures, the thermal conditioning system 100 comprises a fourth bypass branch E connecting a seventh connection point 17 disposed on the main loop A downstream of the fourth connection point 14 and in upstream of the sixth connection point 16 to an eighth connection point 18 disposed on the main loop A downstream of the second heat exchanger 32 and upstream of the first connection point 11.

[133] The fourth bypass branch E is a bypass branch of the second heat exchanger 32 and of the third expansion device 43. In other words, the refrigerant fluid circulating in the main loop A downstream of the second compression device 2 can, while circulating in the fourth bypass branch E, bypass the third expansion device 43 and the second heat exchanger 32.

[134] The thermal conditioning system 100 also comprises a fifth bypass branch F connecting a ninth connection point 19 disposed on the first bypass branch B downstream of the second evaporator 4 to a tenth connection point 20 disposed on the main loop A downstream of the first internal exchanger 5 and upstream of the first expansion valve 41 .

[135] The thermal conditioning system 100 may also include a sixth bypass branch G connecting an eleventh connection point 21 disposed on the main loop A downstream of the tenth connection point 20 and upstream of the first regulator 41 to a twelfth point connection 22 disposed on the main loop A downstream of the first evaporator 3 and upstream of the first compression device 1, the sixth bypass branch G comprising successively a fourth expander 44 and a third heat exchanger

33 configured to exchange heat with an air flow Fi inside a passenger compartment of a motor vehicle. The third heat exchanger 33 thus makes it possible to cool the passenger compartment of the vehicle. A mobile shutter, not shown, makes it possible to adjust the flow of air exchanging heat with the flow of interior air Fi. The third heat exchanger 33 and the first heat exchanger 31 are both arranged in the heating, ventilation and/or air conditioning installation. In order to simplify the representation, the third heat exchanger 33 and the first heat exchanger 31 are not represented one beside the other. Two distinct arrows thus designate the same interior air flow Fi.

[136] The thermal conditioning system 100 further comprises a seventh bypass branch H connecting a thirteenth connection point 23 disposed on the main loop A downstream of the second heat exchanger 32 and upstream of the eighth connection point 18 to a fourteenth connection point 24 arranged on the main loop A downstream of the twelfth connection point 22 and upstream of the first compression device 1. This seventh bypass branch H makes it possible to ensure operation according to a so-called heat pump mode in which the heat rejected in the internal air flow Fi at the level of the first heat exchanger 31 is partly taken from the external air flow Fe at the level of the second heat exchanger 32.

[137] The fourteenth connection point 24 can be confused with the twelfth connection point 22.

[138] In the example shown, the main loop A comprises a fourth heat exchanger 34 disposed downstream of the second heat exchanger 32 and upstream of the first connection point 1 1 , the fourth heat exchanger

34 being configured to exchange heat with a flow of air Fe outside a passenger compartment of the vehicle. When the seventh bypass branch H is present, the fourth heat exchanger 34 is arranged on the main loop A downstream of the thirteenth connection point 23 and upstream of the first connection point 11. When the fourth bypass branch E is also present, the fourth heat exchanger 34 is arranged downstream of the thirteenth connection point 23 and upstream of the eighth connection point 18. [139] The thermal conditioning system also comprises a two-fluid heat exchanger 6 disposed jointly on the main refrigerant loop A downstream of the second heat exchanger 32 and upstream of the eighth connection point 18, and on an auxiliary loop 9 of liquid coolant in such a way as to allow heat exchange between the refrigerant fluid and the coolant liquid.

[140] The two-fluid exchanger 6 is arranged upstream of the fourth heat exchanger 34 in the direction of circulation of the refrigerant fluid.

[141] The two-fluid exchanger 6 can be present without the fourth heat exchanger 34 being present. Likewise, the fourth heat exchanger 34 can be present without the two-fluid exchanger 6 being present. These variants have not been shown.

[142] The auxiliary coolant loop 9 includes a fifth heat exchanger 35 configured to exchange heat with a flow of air Fe outside a passenger compartment of the vehicle. The heat absorbed from the refrigerant fluid at the two-fluid heat exchanger 6 can thus be dissipated in the outside air flow Fe at the fifth exchanger 35. The auxiliary coolant loop 9 comprises a pump 70 configured to circulate the liquid coolant. The auxiliary loop 9 of heat transfer liquid is isolated from the first secondary loop 7 and from the second secondary loop 8.

[143] The second heat exchanger 32 can operate, according to certain operating modes, as a condenser of the high pressure gaseous refrigerant fluid. The two-fluid exchanger 6 arranged downstream of the second exchanger 32 can make it possible, depending on the operating conditions, to complete the condensation or to perform sub-cooling of the refrigerant fluid leaving the second exchanger 32. The fourth heat exchanger 34 can ensure a sub-cooling of the refrigerant leaving the two-fluid heat exchanger 6.

[144] Preferably, the fourth heat exchanger 34 is arranged upstream of the fifth heat exchanger 35 in a direction of flow of the outside air flow Fe. The fifth heat exchanger 35 is arranged upstream of the second heat exchanger. heat 32 according to a direction of flow of the flow of outside air Fe. In other words, the flow of outside air Fe crosses in order the fourth heat exchanger 34, then the fifth heat exchanger 35, then the second heat exchanger 32. The fourth heat exchanger 34 thus receives an air flow which has not been heated by passing through another heat exchanger. heat. This arrangement is conducive to ensuring sub-cooling of the refrigerant fluid when the second exchanger 32 operates as a condenser for the gaseous refrigerant fluid at high pressure.

[145] According to the embodiments of Figures 1 to 3, the main loop A comprises a coolant accumulation device 26 disposed downstream of the fourteenth connection point 24 and upstream of the first compression device 1. Accumulation device 26 is a low pressure accumulator. This accumulator makes it possible to create a reserve of refrigerant fluid making it possible to compensate for variations in the quantity of refrigerant fluid circulating in the circuit 10.

[146] According to a fourth embodiment, illustrated in Figure 4, the main loop A comprises a coolant accumulation device 26 'disposed downstream of the eighth connection point 18 and upstream of the first connection point 1 1 . The accumulation device 26' is a dehydrating bottle.] In this case, the accumulator 26 is not present and the dehydrating bottle 26' is the only refrigerant accumulation device.

[147] In the second illustrated embodiment, corresponding to Figure 2, the main loop A comprises a second internal exchanger 28 disposed jointly on the main loop A downstream of the refrigerant accumulation device 26 and upstream of the first compression device 1, and on the main loop A downstream of the tenth connection point 20 and upstream of the eleventh connection point 21 .

[148] The second internal exchanger 28 comprises a first heat exchange section 28a arranged on the main loop A between the tenth connection point 20 and the eleventh connection point 21 . The second internal exchanger 28 comprises a second heat exchange section 28b arranged on the main loop A between the refrigerant fluid accumulation device 26 and the inlet 1a of the first compression device 1 . The second internal exchanger 28 is configured to allow heat exchange between the refrigerant fluid in the first heat exchange section 28a and the coolant in the second heat exchange section 28b.

[149] According to a third embodiment, corresponding to the diagram of Figure 3, the refrigerant circuit 10 comprises a third internal exchanger 29 disposed jointly on the main loop A downstream of the first connection point 1 1 and upstream of the first internal exchanger 5, and on the main loop A downstream of the second connection point 12 and upstream of the second compression device 2.

[150] The third internal exchanger 29 comprises a first heat exchange section 29a disposed on the main loop A between the first connection point 1 1 and the first internal exchanger 5. The third internal exchanger 29 comprises a second exchange section 29b disposed on the main loop A between the second connection point 12 and the inlet 2a of the compression device 2. The third internal exchanger 29 is configured to allow heat exchange between the refrigerant fluid in the first exchange section heat 29a and the coolant in the second heat exchange section 29b. In FIG. 3, the dotted lines above the sign 29a indicate that the refrigerant fluid circulating in the first bypass branch B does not participate in the heat exchange in the third internal exchanger 29. The third internal exchanger 29 can be present whereas the second internal exchanger 28 is not present, as is the case in FIG. 4. The thermal conditioning system 100 can simultaneously comprise the first internal exchanger 5, the second internal exchanger 28 and the third internal exchanger 29. In order to simplify the figures, this configuration has not been shown.

[151] According to one embodiment illustrated in Figure 5, the thermal conditioning system 100 further comprises an eighth bypass branch J connecting a fifteenth connection point 45 disposed on the main loop A downstream of the fourteenth connection point 24 and upstream of the first compression device 1 at a sixteenth connection point 46 arranged on the first bypass branch B downstream of the ninth connection point 19 and upstream of the second connection point 12. [152] The sixteenth connection point 46 can be confused with the second connection point 12. This eighth bypass branch allows the low-pressure refrigerant at the outlet of the third heat exchanger 33 to be sucked in both by the first device compression device 1 and by the second compression device 2. Particularly effective cooling of the vehicle interior can thus be ensured.

[153] The main loop A comprises a first shut-off valve 51 arranged between the first connection point 11 and the tenth connection point 20. In the example shown, the first shut-off valve 51 is arranged between the first connection point 1 1 and the internal exchanger 5. Similarly, the fourth bypass branch E comprises a second stop valve 52. The second stop valve 52 is arranged between the seventh connection point 17 and the eighth point connection 18. The seventh bypass branch H also includes a third shut-off valve 53. The third shut-off valve 53 is arranged between the thirteenth connection point 23 and the fourteenth connection point 24.

[154] According to the example shown, the first bypass branch B comprises a first non-return valve 61 configured to block circulation of the refrigerant fluid from the ninth connection point 19 to the second evaporator 4. Similarly, the fifth branch of branch F comprises a second non-return valve 62 configured to block circulation of the refrigerant fluid from the tenth connection point 20 to the ninth connection point 19. The sixth bypass branch G comprises a third non-return valve 63 configured to block a circulation of the refrigerant fluid from the twelfth connection point 22 to the third heat exchanger 33. The seventh bypass branch H also includes a fourth non-return valve 64 configured to block circulation of the refrigerant fluid from the fourteenth connection point 24 to the thirteenth connection point. connection 23. Non-return valves help to allow operation in various modes operating conditions, as will be detailed later.

[155] Non-return valves can be replaced by shut-off valves. These variant embodiments have not been shown. [156] According to one embodiment, illustrated in Figure 2, the thermal conditioning system 100 comprises a first housing 80 defining a receiving volume. A portion of main loop A extending between the third connection point 13 and the second connection point 12 is contained inside the first casing 80. A portion of the second branch C comprising the fifth connection point 15 is also contained inside the first housing 80. A portion of the third branch D comprising the fifth connection point 15 is also contained inside the first housing 80.

[157] The first housing 80 defines a sealed volume to the refrigerant fluid. The first casing 80 defines a closed volume in which part of the refrigerant circuit 10 is contained. The first casing 80 and the portions of the refrigerant circulation circuit contained inside the first casing 80 form a first unitary module.

[158] The first housing 80 has inlets/outlets 81, 81b, 82, 83, 84 of coolant fluid, each inlet/outlet allowing a fluid connection with a portion of the coolant circuit 10. The inlet 81 allows a fluidic connection between the first casing 80 and the main loop portion A exiting from the first compression device 1. The inlet 81b allows a fluidic connection between the first casing 80 and the first bypass branch portion B coming from the second evaporator 4 The outlet 82 allows a fluidic connection between the first casing 80 and the main loop portion A entering the second compression device 2. The outlet 83 allows a fluidic connection between the first casing 80 and the third bypass branch D. inlet/outlet 84 allows a fluidic connection between the first casing 80 and the second bypass branch C.

[159] Three-way valves 54 and 55 are contained within first housing 80. When individual valves 54a, 54b, 54c and 55a, 55b, 55c are used instead of three-way valves, these individual valves are contained inside the first casing 80. [160] The grouping of several inputs / outputs and part of the refrigerant circuit 10 in the form of a first unitary module facilitates assembly, and allows the use of standardized components.

[161] In the embodiment illustrated in Figure 2, the thermal conditioning system 100 includes a second housing 85 defining a receiving volume. The fourth bypass branch E, the third regulator 43 and a main loop portion A extending between the third regulator 43 and the seventh connection point 17 are contained inside the second housing 85. Similarly, the second regulator 42, the first shut-off valve 51, the internal exchanger 5 and a portion of main loop A extending between the eighth connection point 18 and the internal exchanger 5 are contained inside the second casing 85.

[162] The second housing 85 and the components contained inside the second housing 85 form a second unitary module. Assembly is thus facilitated, since only four refrigerant fluid inlets/outlets need to be connected. The test is also facilitated, since this second unitary module can be tested before its integration into the thermal conditioning system.

[163] The second housing 85 has inlets/outlets 86, 87, 88, 89, 90 of coolant fluid, each inlet/outlet allowing a fluid connection with a portion of the coolant circuit 10. The inlet 86 allows a connection connection between the second casing 85 and the main loop portion A exiting from the first heat exchanger 31. The outlet 87 allows a fluid connection between the second casing 85 and the portion of the first bypass branch B exiting from exiting from the second section exchanger 5b of the first internal exchanger 5. The outlet 88 allows a fluidic connection between the second casing 85 and the main loop portion A exiting from the first heat exchange section 5a of the first internal exchanger 5. The outlet 89 allows a fluidic connection between the second casing 85 and the main loop portion A exiting from the third regulator 43. The inlet 90 allows a fluidic connection between the second casing 85 and the po main loop rtion A exiting the fourth heat exchanger 34. [164] The thermal conditioning system 100 can integrate the first unitary module and the second unitary module, as is the case in FIG. 2. The thermal conditioning system 100 can also use discrete components not forming part of a unitary module, as is the case in the embodiments corresponding in particular to the other figures 2, 3, 4. According to variants not illustrated, the thermal conditioning system 100 can integrate a single unitary module, which can be either the first is the second unitary module.

[165] The described architecture allows thermal conditioning system 100 to operate in many different modes of operation. A few particular modes of operation will now be described.

[166] The invention also relates to a method of operating a thermal conditioning system 100 as described previously, in a so-called mode of inactivation of the second evaporator 4. According to this method of operation, illustrated in FIG. :

- the refrigerant is divided at the first connection point 1 1 into a first flow Q1 circulating in the first bypass branch B and a second flow Q2 circulating in the main loop A,

- the first flow Q1 circulates successively in the second regulator 42 where it undergoes an expansion, in the first internal exchanger 5, in the second evaporator 4,

- the second flow Q2 circulates in the first internal exchanger 5, and the first flow Q1 is in the state of superheated steam at the outlet of the first internal exchanger 5.

[167] More specifically, the first flow Q1 circulates in the second heat exchange section 5b of the first internal exchanger 5. The second flow Q2 circulates in the first heat exchange section 5a of the first internal exchanger 5. The refrigerant in outlet of the second heat exchange section 5b of the internal exchanger 5 is in the state of superheated steam.

[168] Superheat means the difference between the actual temperature of the refrigerant fluid, which is at a given pressure, and the condensation temperature refrigerant corresponding to this given pressure. Zero superheat corresponds to saturated steam. When the superheat is positive, the refrigerant is entirely in vapor form. The superheating of the refrigerant fluid at the outlet of the second heat exchange section 5b is for example between 5°C and 10°C.

[169] In this mode of operation, the second evaporator 4 is supplied with refrigerant in the form of superheated vapor. The heat exchange in the second evaporator 4 is negligible under these conditions. This mode of operation makes it possible to minimize the enthalpy of the refrigerant fluid at the outlet of the first heat exchange section 5a of the internal exchanger 5, without carrying out any heat exchange in the second evaporator 4. The cooling capacity of the system thermal conditioning 100 is then maximized, and can be distributed between the first evaporator 3 and the third heat exchanger 33.

[170] The invention also relates to a method of operating a thermal conditioning system 100 as described above, in a so-called passenger compartment heating mode with energy recovery. According to this method of operation, illustrated in Figure 7:

- a first flow Q1 of low-pressure refrigerant circulates in the first compression device 1 where it passes to an intermediate pressure,

- a second flow Q2 of refrigerant fluid at intermediate pressure circulates in the first bypass branch B and joins the first flow Q1, forming a total flow Q of refrigerant fluid at intermediate pressure,

- the total flow Q of refrigerant fluid at intermediate pressure circulates in the second compression device 2 where it passes at high pressure, in the first heat exchanger 31 where it yields heat to the internal air flow Fi, in the fourth derivation branch E,

- is divided into a third flow Q3 circulating in the first bypass branch B and a fourth flow Q4 circulating in the main loop A, the third flow Q3 circulates successively in the second regulator 42 where it passes at intermediate pressure, in the first exchanger internal 5, in the second evaporator 4 where it absorbs heat, and joins the first flow Q1 of refrigerant fluid circulating in the main loop A at the outlet of the first compression device 1,

- The fourth flow Q4 circulates in the first internal exchanger 5, in the first expansion valve 41 where it passes at low pressure, in the first evaporator 3 where it absorbs heat, and joins the first compression device 1 .

[171] The flow through the second compression device 2 is greater than the flow through the first compression device 1. The total flow Q of high-pressure refrigerant fluid is divided at the level of the first connection point 11, thus forming a third flow Q3 and a fourth flow Q4. The third flow Q3 circulates successively in the second expansion valve 42 then in the second heat exchange section 5b of the first internal exchanger 5. The fourth flow Q4 circulates in the first heat exchange section 5a of the first internal exchanger 5, then in the first expansion valve 41 and the first evaporator 3. As no flow of refrigerant fluid circulates in the fifth bypass branch F, the third flow Q3 is equal to the second flow Q2 when the conditioning system is in steady state. Similarly, the fourth flow Q4 is equal to the first flow Q1 when the conditioning system is in steady state. By flow rate is meant here a mass flow rate. Steady state means that the thermal conditioning system has reached a state of thermodynamic equilibrium. The third regulator 43 is in the closed position, and blocks the circulation of refrigerant fluid downstream of the seventh connection point 17. The fourth regulator 44 is also closed. The non-return valve 62 prevents a circulation of refrigerant fluid from the tenth connection point 20 to the ninth connection point 19.

[172] This mode of operation makes it possible to heat the passenger compartment by dissipating the heat of the refrigerant fluid circulating successively in the two compression devices 1, 2 in the interior air flow Fi. The thermodynamic cycle is completed by absorbing heat at the level of the first evaporator 3 and the second evaporator 4. This heat is recovered respectively from the first element 25 and from the second element 30 of the traction chain. The distribution between the heat absorbed at the level of the first evaporator 3 and the heat absorbed at the level of the second evaporator 4 is carried out by adjusting the speed of rotation of the first compression device 1 and of the second compression device 2. This mode makes it possible to obtain a high heating power without having recourse to an additional heating device. Indeed, the use of two compressors as well as the division of the total flow Q into a first flow Q3 and a flow Q4 makes it possible to maximize the quantity of heat transferred at the level of the first heat exchanger 31. The separation of the flows upstream of the first internal exchanger 5 makes it possible to maximize the variation in enthalpy of the refrigerant fluid when the latter passes through the first evaporator 3. The recovery of the energy from the first element 25 of the traction chain can thus be particularly effective. The efficiency of the energy recovery makes it possible not to use an additional heating device.

[173] Figure 8 describes another mode of operation of the thermal conditioning system 100. According to this method of operating a thermal conditioning system 100 as described previously, in a so-called cabin cooling and powertrain cooling mode:

- a first low-pressure refrigerant flow Q1 circulates in the first compression device 1 where it passes to intermediate pressure, then circulates successively in the second bypass branch C,

- a second flow Q2 of refrigerant circulates successively in the second compression device 2 where it passes at intermediate pressure and in the second bypass branch C, and joins the first flow Q1, forming a total flow Q of refrigerant at intermediate pressure ,

- the total flow Q of refrigerant fluid at intermediate pressure circulates successively in the third bypass branch D, in the second heat exchanger 32 where it yields heat to the external air flow Fe, is divided into a third circulating flow Q3 in the first bypass branch B and a fourth flow Q4 circulating in the main loop A, the third flow Q3 circulates successively in the second expansion valve 42 where it undergoes expansion, in the second heat exchange section 5b of the first internal exchanger 5 , in the second evaporator 4 where it absorbs heat, the fourth flow Q4 circulates successively in the first heat exchange section 5a of the first internal exchanger 5, in the fourth expansion valve 44 where it passes at low pressure, into the third heat exchanger 33 where it absorbs heat from the interior air flow Fi.

[174] The first flow Q1 generated by the first compression device 1 joins, at the level of the fifth connection point 15, the second flow Q2 generated by the second compression device 2. The flow of refrigerant fluid circulating in the main loop A downstream of the fourth connection point 14 is zero, since the second shut-off valve 52 and the third regulator 43 are both in the closed position. The total flow Q of coolant is divided at the first connection point 11, thus forming the third flow Q3 and the fourth flow Q4. The third flow Q3 circulates successively in the second expansion valve 42 then in the second heat exchange section 5b of the first internal exchanger 5. The fourth flow Q4 circulates successively in the first heat exchange section 5a of the first internal exchanger 5, then in the fourth expansion valve 44. As no flow of refrigerant fluid circulates in the fifth bypass branch F, the third flow Q3 is equal to the second flow Q2 in steady state. Similarly, the fourth rate Q4 is equal to the first rate Q1 in steady state. The first expansion valve 41 is in the closed position and the non-return valve 62 prevents circulation of refrigerant fluid from the tenth connection point 20 to the ninth connection point 19.

[175] The invention also relates to a method of operating a thermal conditioning system 100 as described above, in a so-called battery heating and energy recovery mode. According to this method of operation, illustrated in Figure 9:

- a flow rate Q the low-pressure refrigerant circulates successively in the first compression device 1 where it passes at an intermediate pressure, in the second compression device 2 where it passes at high pressure, in the first heat exchanger 31, in the fourth bypass branch E, in the first bypass branch B, in the second expansion valve 42, in the second evaporator 4 where it transfers heat, in the fifth bypass branch F, in the first expansion valve 41 where it passes to low pressure, in the first evaporator 3 where it absorbs heat, and joins the first compression device 1. [176] In this so-called battery heating and energy recovery operating mode, the refrigerant fluid successively passes through the first 1 and the second 2 compression device which are then arranged in series. The high-pressure refrigerant fluid passes through the second expansion valve 42 without undergoing expansion, which means that the refrigerant fluid reaches the second evaporator 4 in a state of high temperature and high pressure. The high-pressure refrigerant fluid thus transfers heat to the second element 30 of the transmission chain. The refrigerant fluid leaving the second evaporator 4 cannot join the inlet of the second compression device 2, because at the second connection point 12 the circulation of the refrigerant fluid coming from the first bypass branch B is blocked. The refrigerant fluid therefore travels through the fifth bypass branch F and joins the main loop A at the level of the tenth connection point 20. The refrigerant fluid is expanded in the first expansion device 41, and absorbs heat from the first element 25 of the traction chain at the level of the first evaporator 3. The refrigerant fluid then joins the accumulator 26 then the inlet 1a of the first compression device 1 . The first shut-off valve 51 is closed, as are the third regulator 43, the fourth regulator 44 and the third shut-off valve 53.

[177] Heating of the second element 30 of the traction chain can thus be ensured. Part of the heat transferred to the second element 30 comes from the heat taken from the first element 25 of the traction chain. For example, the battery 30 can be heated while recovering the heat given off by the electronic module 25, which minimizes the energy expended.

[178] According to a variant of the so-called battery heating and energy recovery mode of operation, not shown, the flow of low-pressure refrigerant fluid circulates successively in the first compression device 1 where it passes to high pressure, in the second bypass branch C, in the first heat exchanger 31 . The rest of the route is the same. According to this variant, only the first compression device 1 operates. The second compression device 2 does not work, and is bypassed by the high pressure refrigerant fluid. [179] Figure 10 illustrates a method of operating a thermal conditioning system 100 as described above, in a so-called accelerated cooling mode. According to this method of operation:

- a flow Q of low-pressure refrigerant is divided between a first flow Q1 and a second flow Q2,

- the first flow Q1 circulates in the first compression device 1 where it passes to an intermediate pressure,

- the second flow Q2 circulates in the second compression device 2 where it passes to an intermediate pressure, circulates in the second bypass branch C and joins the first flow Q1, forming a flow Q of refrigerant fluid at intermediate pressure, the flow Q circulates in the third bypass branch D, joins the main loop A, circulates successively in the second heat exchanger 32 where it yields heat to the external air flow Fe, in the fourth expansion device 44 where it switches to low pressure, in the third heat exchanger 33 where it absorbs heat from the interior air flow Fi.

[180] The low-pressure refrigerant at the outlet of the third exchanger 33 joins the fifteenth connection point 45 at which it again divides into a first flow Q1 and a second flow Q2. In this mode of operation, neither the first evaporator 3 nor the second evaporator 4 are traversed by a flow of refrigerant fluid. The entire coolant flow passes through the second heat exchanger 32 as well as the third heat exchanger 33.

[181] Many other operating modes are also possible. For example, according to a so-called heat pump mode of operation, not shown:

- a flow Q of low-pressure refrigerant circulates successively in the first compression device 1 where it passes at an intermediate pressure, in the second compression device 2 where it passes at high pressure, in the first heat exchanger 31 where it passes transfers heat to the internal air flow Fi, in the third regulator 43 where it passes at low pressure, in the second heat exchanger 32 where it absorbs heat from the external air flow Fe, in the seventh bypass branch H, and joins the first compression device 1.

[182] So-called dehumidification operating modes, in which the interior air flow Fi is cooled at the level of its passage through the third exchanger 33 and heated at the level of the first exchanger 31 are possible. According to one of the dehumidification modes, the two compression devices are active simultaneously, with a series circulation of the refrigerant fluid through the two compression devices. According to another mode of dehumidification, only the first compression device 1 is in operation and no flow of refrigerant fluid passes through the second compression device.

Claims

Claims [Claim 1] A thermal conditioning system (100) comprising a refrigerant circuit (10) configured to circulate a refrigerant fluid, the refrigerant circuit (10) comprising: A main loop (A) successively comprising, depending on the direction of circulation of the refrigerant fluid: -- a first compression device (1), -- a second compression device (2), -- a first heat exchanger (31) configured to exchange heat with a first heat transfer fluid (F1), -- a first regulator (41), -- a first evaporator (3), A first bypass branch (B) connecting a first connection point (1 1) arranged on the main loop (A) downstream of the first heat exchanger (31) and upstream of the first regulator (41) to a second point of connection (12) arranged on the main loop (A) downstream of the first compression device (1) and upstream of the second compression device (2), the first bypass branch (B) successively comprising a second pressure reducer (42) and a second evaporator (4), a first internal exchanger (5) arranged jointly on the main loop (A) downstream of the first connection point (1 1) and upstream of the first expansion valve (41), and on the first branch bypass (B) downstream of the second expansion valve (42) and upstream of the second evaporator (4), the thermal conditioning system (100) being configured to operate at least according to an operating mode in which the refrigerant fluid circulating in the first branch of bypass (B) is in the superheated steam state at the outlet of the first internal exchanger (5). [Claim 2] Thermal conditioning system according to claim 1, in which the thermal conditioning system (100) is a thermal conditioning system of a motor vehicle, in which the first heat transfer fluid (F1) is an air flow interior (Fi) to a passenger compartment of a motor vehicle, in which the first evaporator (3) is thermally coupled with a first element (25) of a traction chain of a motor vehicle, the first element (25) comprising in particular an electronic module for controlling an electric traction motor of the vehicle, and in which the second evaporator (4) is thermally coupled with a second element (30) of a traction chain of a motor vehicle, the second element (30) comprising in particular an electric energy storage battery . [Claim 3] Thermal conditioning system according to claim 1 or 2, comprising a second branch branch (C) connecting a third connection point (13) arranged on the main loop (A) downstream of the first compression device (1 ) and upstream of the second connection point (12) to a fourth connection point (14) disposed on the main loop (A) downstream of the second compression device (2) and upstream of the first heat exchanger (31) . [Claim 4] Thermal conditioning system according to one of the preceding claims, comprising a third branch branch (D) connecting a fifth connection point (15) arranged on the second branch branch (C) to a sixth connection point (16) disposed on the main loop (A) downstream of the first heat exchanger (31) and upstream of the first connection point (1 1). [Claim 5] Thermal conditioning system according to one of the preceding claims, in which the main loop (A) successively comprises a third expander (43) and a second heat exchanger (32) configured to exchange heat with a second heat transfer fluid (F2), the second heat transfer fluid (F2) being a flow of air (Fe) outside the passenger compartment of a motor vehicle. [Claim 6] Thermal conditioning system according to one of the preceding claims in combination with Claim 3 and with Claim 4, comprising a fourth branch branch (E) connecting a seventh connection point (17) arranged on the main loop (A) downstream of the fourth connection point (14) and upstream of the sixth connection point connection (16) to an eighth connection point (18) disposed on the main loop (A) downstream of the second heat exchanger (32) and upstream of the first connection point (1 1). [Claim 7] Thermal conditioning system according to one of the preceding claims, comprising a fifth branch branch (F) connecting a ninth connection point (19) arranged on the first branch branch (B) downstream of the second evaporator ( 4) at a tenth connection point (20) arranged on the main loop (A) downstream of the first internal exchanger (5) and upstream of the first regulator (41). [Claim 8] Thermal conditioning system according to the preceding claim, comprising a sixth branch branch (G) connecting an eleventh connection point (21) disposed on the main loop (A) downstream of the tenth connection point (20) and upstream of the first regulator (41) to a twelfth connection point (22) arranged on the main loop (A) downstream of the first evaporator (3) and upstream of the first compression device (1), the sixth bypass branch (G) successively comprising a fourth expansion valve (44) and a third heat exchanger (33) configured to exchange heat with an air flow (Fi) inside a passenger compartment of a motor vehicle. [Claim 9] Thermal conditioning system according to one of the preceding claims, in which the first compression device (1) and the second compression device (2) are two independent compressors. [Claim 10] Thermal conditioning system according to one of the preceding claims, in which the first internal exchanger (5) is a plate exchanger. [Claim 11] Method of operating a thermal conditioning system (100) according to one of claims 1 to 10, in a so-called mode of inactivation of the second evaporator (4), in which: - the refrigerant fluid is divided at the first connection point (1 1 ) into a first flow (Q1 ) circulating in the first bypass branch (B) and a second flow (Q2) circulating in the main loop (A), - the first flow (Q1) circulates successively in the second regulator (42) where it undergoes expansion, in the first internal exchanger (5), in the second evaporator (4), - the second flow (Q2) circulates in the first internal exchanger (5), and in which the first flow (Q1) is in the state of superheated steam at the outlet of the first internal exchanger (5). [Claim 12] Method of operating a thermal conditioning system (100) according to one of Claims 1 to 10 in combination with Claim 2 and with Claim 6, in a so-called passenger compartment heating mode with energy recovery , in which : - a first flow (Q1) of low-pressure refrigerant circulates in the first compression device (1) where it passes to an intermediate pressure, - a second flow (Q2) of refrigerant at intermediate pressure circulates in the first bypass branch (B) and joins the first flow (Q1), forming a total flow (Q) of refrigerant at intermediate pressure, - the total flow (Q) of refrigerant fluid at intermediate pressure circulates in the second compression device (2) where it passes at high pressure, in the first heat exchanger (31) where it yields heat to the air flow interior (Fi), in the fourth derivation branch (E), - is divided into a third flow (Q3) circulating in the first bypass branch (B) and a fourth flow (Q4) circulating in the main loop (A), the third flow (Q3) circulates successively in the second regulator (42 ) where it passes at intermediate pressure, in the first internal exchanger (5), in the second evaporator (4) where it absorbs heat, and joins the first flow (Q1) of refrigerant fluid circulating in the main loop (A) at the output of the first compression device (1), - the fourth flow (Q4) circulates in the first internal exchanger (5), in the first regulator (41) where it passes at low pressure, in the first evaporator (3) where it absorbs heat, and joins the first device compression (1 ). [Claim 13] A method of operating a thermal conditioning system (100) according to one of claims 1 to 10 in combination with claims 2 to 5, the first internal heat exchanger (5) comprising a first section of heat exchange (5a) arranged on the main loop (A) and a second heat exchange section (5b) arranged on the first bypass branch B, in a so-called passenger compartment cooling and powertrain cooling mode, in which: - a first flow (Q1) of low-pressure refrigerant circulates in the first compression device (1) where it passes to intermediate pressure, then circulates successively in the second bypass branch (C), - a second flow (Q2) of refrigerant circulates successively in the second compression device (2) where it passes at intermediate pressure and in the second bypass branch (C), and joins the first flow (Q1), forming a flow total (Q) of refrigerant at intermediate pressure, - the total flow (Q) of refrigerant fluid at intermediate pressure circulates successively in the third bypass branch (D), in the second heat exchanger (32) where it yields heat to the external air flow (Fe), is divided into a third flow (Q3) circulating in the first bypass branch (B) and a fourth flow (Q4) circulating in the main loop (A), the third flow (Q3) circulates successively in the second regulator (42) where it undergoes expansion, in the second heat exchange section (5b) of the first internal exchanger (5), in the second evaporator (4) where it absorbs heat, the fourth flow (Q4) circulates successively in the first heat exchange section (5a) of the first internal exchanger (5), in the fourth expansion valve (44) where it passes at low pressure, in the third heat exchanger (33) where it absorbs heat from the air flow interior (Fi). [Claim 14] Method of operating a thermal conditioning system (100) according to one of Claims 1 to 10 in combination with Claims 6 and 7, in a so-called battery heating and energy recovery mode in which: - a flow rate (Q) the low-pressure refrigerant fluid circulates successively in the first compression device (1) where it passes at an intermediate pressure, in the second compression device (2) where it passes at high pressure, in the first heat exchanger (31), in the fourth bypass branch (E), in the first bypass branch (B), in the second expansion valve (42), in the second evaporator (4) where it releases heat, in the fifth branch of bypass (F), in the first expander (41) where it passes at low pressure, in the first evaporator (3) where it absorbs heat, and joins the first compression device (1).