FR3092653A1 - Thermal management device for an electric or hybrid motor vehicle - Google Patents

Abstract

The present invention relates to a thermal management device comprising an indirect air conditioning circuit (1) comprising: - a first refrigerant fluid loop (A) comprising a compressor (3), a bifluid heat exchanger (5), a first cooling device. expansion (7), a first heat exchanger (9), a second expansion device (11), a second heat exchanger (13), and - a first bypass pipe (30), - a second bypass pipe ( 40) comprising a third expansion device (17) arranged upstream of a first cooler (15), - a third bypass pipe (70) comprising a fourth expansion device (77) and a second cooler (75), - a first internal heat exchanger (19), - a second internal heat exchanger (19 '), - a second heat transfer fluid loop (B), the bifluid heat exchanger (5) being arranged jointly on the one hand on the first refrigerant fluid loop (A) before l of the compressor (3), between said compressor (3) and the first expansion device (7), and on the other hand on the second heat transfer fluid loop (B). Figure for the abstract: Fig. 1

Description

Thermal management device for an electric or hybrid motor vehicle

The invention relates to the field of motor vehicles and more particularly to a thermal management device for an electric or hybrid motor vehicle.

Current motor vehicles more and more often include a thermal management device comprising an air conditioning circuit. Generally, in a "conventional" air conditioning circuit, a refrigerant fluid passes successively through a compressor, a first heat exchanger, called a condenser, placed in contact with an air flow outside the motor vehicle to release heat, a device expansion and a second heat exchanger, called evaporator, placed in contact with a flow of air inside the motor vehicle to cool it.

There are also more complex air conditioning circuit architectures which make it possible to obtain an invertible air conditioning circuit, i.e. it can absorb heat energy in the outside air at the level of the first heat exchanger, then called evapo-condenser. The heat energy can also be absorbed at hot spots of the motor vehicle, for example by recovering heat energy from one or more cooling loops of the electric motor, power electronics or even batteries. . This solution offers the advantage of avoiding icing of the front face (evapo-condenser) and of being able to close the front face in order to reduce the drag of the vehicle (and therefore increase its range). The heat energy absorbed is then returned to the passenger compartment, in particular by means of a third dedicated heat exchanger.

This is possible in particular by using an indirect air conditioning circuit. By indirect is meant here that the air conditioning circuit comprises two circulation loops for two distinct fluids (such as, for example, a refrigerant fluid and glycol water) in order to carry out the various heat exchanges.

The air conditioning circuit thus comprises a first refrigerant fluid loop in which a refrigerant fluid circulates, a second heat transfer fluid loop in which a heat transfer fluid circulates, and a two-fluid heat exchanger arranged jointly on the first refrigerant fluid loop and on the second heat transfer fluid loop, so as to allow heat exchange between said loops.

Such an air conditioning circuit allows use according to different operating modes. In the context of an electric or hybrid vehicle, the thermal management of elements such as the batteries, the electronic components and the electric motor is carried out by a secondary thermal management loop. However, this architecture may not be sufficient to ensure the evacuation of the heat accumulated in the coolant in certain modes, in particular when the batteries need a high cooling power, for example during a charge or a rapid discharge. In addition, in cold weather, the heat energy generated by elements such as batteries and electronic components can be recovered in order to participate in the heating of the interior air flow intended for the passenger compartment.

One of the aims of the present invention is therefore to at least partially remedy the drawbacks of the prior art and to propose an improved thermal management device allowing the thermal management of elements such as batteries.

The present invention therefore relates to a thermal management device comprising an indirect air conditioning circuit for a motor vehicle comprising:
- a first refrigerant loop in which a refrigerant fluid circulates, said first refrigerant fluid loop comprising, in the direction of circulation of the refrigerant fluid, a compressor, a two-fluid heat exchanger, a first expansion device, a first heat exchanger, a second expansion device, a second heat exchanger being intended to be crossed by a flow of air external to the motor vehicle, and
* a first pipe for bypassing the second heat exchanger comprising a first shut-off valve,
* a second pipe bypassing the first expansion device and the first heat exchanger, said second bypass pipe comprising a third expansion device arranged upstream of a first cooler,
* a third bypass pipe of the second heat exchanger, said third bypass pipe comprising a fourth expansion device arranged upstream of a second cooler,
- a first internal heat exchanger, allowing heat exchange between the high-pressure refrigerant at the outlet of the two-fluid heat exchanger and the low-pressure refrigerant at the outlet of the second heat exchanger or the first bypass line ,
* a second internal heat exchanger allowing heat exchange between the high-pressure refrigerant at the outlet of the first internal heat exchanger and the low-pressure refrigerant flowing in the first bypass line,
- a second heat transfer fluid loop in which a heat transfer fluid circulates,
the two-fluid heat exchanger being arranged jointly on the one hand on the first loop of refrigerant fluid downstream of the compressor, between said compressor and the first expansion device, and on the other hand on the second loop of heat transfer fluid.

According to one aspect of the invention, the fourth expansion device is an electronic expansion valve or a thermostatic expansion valve whose thermostatic bulb is positioned at the outlet of the second cooler. In both cases, the expansion valve can be fitted with a function to stop the circulation of refrigerant fluid.

According to another aspect of the invention, the fourth expansion device is an electronic expansion valve controlled by an electronic control unit.

According to another aspect of the invention, the second heat transfer fluid loop comprises:
- the two-fluid heat exchanger,
- a first heat transfer fluid circulation pipe comprising a third heat exchanger intended to be crossed by a flow of air inside the motor vehicle, and connecting a first junction point arranged downstream of the two-fluid heat exchanger and a second junction point arranged upstream of said two-fluid heat exchanger,
- a second heat transfer fluid circulation pipe comprising a fourth heat exchanger intended to be crossed by a flow of air external to the motor vehicle, and connecting the first junction point arranged downstream of the two-fluid heat exchanger and the second point junction arranged upstream of said two-fluid heat exchanger, and
- A pump arranged downstream or upstream of the two-fluid heat exchanger, between the first junction point and the second junction point.

According to another aspect of the invention, the thermal management device is configured to operate in a cooling mode in which the refrigerant fluid circulates in the first refrigerant fluid loop successively in:
- the compressor where the refrigerant passes at high pressure,
- the two-fluid heat exchanger, at which the coolant transfers heat energy to the heat transfer fluid of the second heat transfer fluid loop,
- the first internal heat exchanger,
- the second internal heat exchanger,
- a first part of the refrigerant fluid passes through the second bypass pipe, passes into the third expansion device where it undergoes a loss of pressure and passes to low pressure, said low pressure refrigerant fluid then circulates in the first cooler, the first bypass pipe and the second internal heat exchanger,
- a second part of the refrigerant fluid passes into the first expansion device, where it undergoes a first loss of pressure and passes to intermediate low, the first heat exchanger which it passes through without loss of heat, the third bypass pipe, the fourth expansion device where it undergoes a second loss of pressure and passes to low pressure and the second cooler,

the two parts of refrigerant fluid joining upstream of the first internal heat exchanger, the refrigerant fluid passing through said first two-fluid heat exchanger before returning to the compressor,
at the level of the second heat transfer fluid loop, the heat transfer fluid leaving the two-fluid heat exchanger circulating in the fourth heat exchanger of the second circulation line.

According to another aspect of the invention, the thermal management device is configured to operate in a heat pump mode in which the refrigerant fluid circulates in the first refrigerant fluid loop successively in:
- the compressor where said refrigerant passes at high pressure,
- the two-fluid heat exchanger, at which the coolant transfers heat energy to the heat transfer fluid of the second heat transfer fluid loop,
- the first internal heat exchanger,
- the second internal heat exchanger,
- the first expansion device where said refrigerant passes to an intermediate pressure,
- the first heat exchanger,
- a first part of the refrigerant fluid passes through the second expansion device where said refrigerant fluid passes at low pressure and the second heat exchanger,
- a second part of the refrigerant fluid passes through the third bypass line, the fourth expansion device where said refrigerant fluid passes at low pressure and the second cooler,
the two parts of low-pressure refrigerant fluid joining upstream of the first two-fluid heat exchanger, the refrigerant passing through said first two-fluid heat exchanger before returning to the compressor,
at the level of the second heat transfer fluid loop, the heat transfer fluid at the outlet of the first two-fluid heat exchanger circulating only in the third heat exchanger of the first circulation line.

According to another aspect of the invention, the thermal management device is configured to operate in another heat pump mode in which the refrigerant fluid circulates in the first refrigerant fluid loop successively in:
- the compressor where said refrigerant passes at high pressure,
- the two-fluid heat exchanger, at which the coolant transfers heat energy to the heat transfer fluid of the second heat transfer fluid loop,
- the first internal heat exchanger,
- the second internal heat exchanger,
- the first expansion device where said refrigerant passes to an intermediate pressure,
- the first heat exchanger,
- the fourth expansion device of the third bypass pipe where said refrigerant fluid passes at low pressure,
- the second cooler,
- the first two-fluid heat exchanger before returning to the compressor,
at the level of the second heat transfer fluid loop, the heat transfer fluid at the outlet of the first two-fluid heat exchanger circulating only in the third heat exchanger of the first circulation line.

Other characteristics and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and non-limiting example, and the appended drawings, among which:

shows a schematic representation of an indirect reversible air conditioning circuit according to a first embodiment,

shows a schematic representation of an indirect reversible air conditioning circuit according to a second embodiment,

shows a schematic representation of an indirect reversible air conditioning circuit according to a third embodiment,

shows a trigger device according to an alternative embodiment,

shows a schematic representation of the second heat transfer fluid loop of the indirect reversible air conditioning circuit of Figures 1 to 3, according to an alternative embodiment,

shows the indirect reversible air conditioning circuit of figure 2 according to a first cooling mode,

shows the indirect reversible air conditioning circuit of Figure 2 according to a second cooling mode,

shows the indirect reversible air conditioning circuit of Figure 2 according to a first heat pump mode,

shows the indirect reversible air conditioning circuit of figure 2 according to a second heat pump mode,

shows the indirect reversible air conditioning circuit of Figure 2 according to a third heat pump mode.

In the various figures, identical elements bear the same reference numbers.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference is to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined and/or interchanged to provide other embodiments.

In the present description, it is possible to index certain elements or parameters, such as for example first element or second element as well as first parameter and second parameter or even first criterion and second criterion, etc. In this case, it is a simple indexing to differentiate and name elements or parameters or criteria that are close but not identical. This indexing does not imply a priority of one element, parameter or criterion over another and such denominations can easily be interchanged without departing from the scope of the present description. This indexing does not imply an order in time either, for example to assess such and such a criterion.

In the present description, “placed upstream” means that one element is placed before another with respect to the direction of circulation of a fluid. Conversely, “placed downstream” means that one element is placed after another in relation to the direction of fluid circulation.

FIG. 1 shows a thermal management device comprising an indirect air conditioning circuit 1 for a motor vehicle. This indirect air conditioning circuit 1 comprises in particular:
- a first refrigerant fluid loop A in which a refrigerant fluid circulates,
- a second heat transfer fluid loop B in which a heat transfer fluid circulates, and
- a two-fluid heat exchanger 5 arranged jointly on the first loop of refrigerant fluid A and on the second loop of heat transfer fluid B, so as to allow heat exchange between said first loop of refrigerant fluid A and said second loop of heat transfer fluid B.

The first refrigerant fluid loop A comprises more particularly in the direction of circulation of the refrigerant fluid:
- a compressor 3,
- the two-fluid heat exchanger 5, arranged downstream of said compressor 3,
- a first expansion device 7,
- a first heat exchanger 9 intended to be crossed by a flow of air 100 inside the motor vehicle,
- a second expansion device 11,
- a second heat exchanger 13 intended to be crossed by a flow of air 200 outside the motor vehicle, and
- a first bypass pipe 30 of the second heat exchanger 13.

By interior airflow 100 is meant here an airflow intended for the passenger compartment of the motor vehicle. The first heat exchanger 9 can thus be arranged in a heating, ventilation and air conditioning device. By exterior air flow 200 is meant an air flow which comes from outside the motor vehicle. The second heat exchanger 13 can thus be arranged on the front face of the motor vehicle.

The first bypass pipe 30 can connect more specifically a first connection point 31 and a second connection point 32.

The first connection point 31 is preferably arranged, in the direction of circulation of the refrigerant fluid, downstream of the first heat exchanger 9, between said first heat exchanger 9 and the second heat exchanger 13. More particularly, and as illustrated in Figure 1, the first connection point 31 is arranged between the first heat exchanger 9 and the second expansion device 11. It is however quite possible to imagine that the first connection point 31 is arranged between the second expansion device 11 and the second heat exchanger 13 as long as the refrigerant fluid has the possibility of bypassing said second expansion device 11 or of crossing it without undergoing a loss of pressure.

The second connection point 32 is for its part preferably disposed downstream of the second heat exchanger 13, between said heat exchanger 13 and the compressor 3.

In order to control the passage of the refrigerant fluid within the first bypass pipe 30 or not, the latter comprises a first shut-off valve 33. In order for the refrigerant fluid not to pass through the second heat exchanger 13, the second expansion valve 11 may in particular comprise a stop function, that is to say it is capable of blocking the flow of refrigerant fluid when it is closed. An alternative may be to place a shut-off valve between the second expansion device 11 and the connection point 71.

Another alternative, not shown, can also be to arrange a three-way valve at the level of the first connection point 31.

The first refrigerant fluid loop A may also include a non-return valve 23 arranged downstream of the second heat exchanger 13, between said second heat exchanger 13 and the second connection point 32 in order to prevent the refrigerant fluid from the first bypass line 30 does not reflux to the second heat exchanger 13.

By stop valve, non-return valve, three-way valve or expansion device with stop function, is meant here mechanical or electromechanical elements that can be controlled by an electronic control unit on board the motor vehicle.

The first refrigerant fluid loop A also comprises a first internal heat exchanger 19 (IHX for "internal heat exchanger") allowing heat exchange between the high-pressure refrigerant fluid at the outlet of the two-fluid heat exchanger 5 and the fluid low-pressure refrigerant at the outlet of the second heat exchanger 13 or of the first bypass pipe 30. This first internal heat exchanger 19 comprises in particular an inlet and an outlet for low-pressure refrigerant fluid coming from the second connection point 32, as well as an inlet and an outlet for high-pressure refrigerant fluid coming from the two-fluid heat exchanger 5.

By high-pressure refrigerant fluid is meant a refrigerant fluid that has undergone a pressure increase at the level of the compressor 3 and that it has not yet suffered a loss of pressure due to one of the expansion devices. By low-pressure refrigerant fluid, we mean a refrigerant fluid having undergone a loss of pressure and at a pressure close to that at the inlet of compressor 3.

The first refrigerant fluid loop A also comprises a second internal heat exchanger 19' (IHX for "internal heat exchanger") allowing heat exchange between the high-pressure refrigerant fluid at the outlet of the first internal heat exchanger 19 and the fluid low-pressure refrigerant circulating in the first bypass line 30. This second internal heat exchanger 19' comprises in particular an inlet and an outlet for low-pressure refrigerant fluid coming from the first connection point 31, as well as an inlet and a high pressure refrigerant fluid outlet from the first internal heat exchanger 19. As illustrated in Figure 1, the low pressure side of the second internal heat exchanger 19' can be arranged downstream of the first shut-off valve 33.

At least one of the first 19 or second 19' internal heat exchangers can be a coaxial heat exchanger, ie comprising two coaxial tubes and between which heat exchanges take place.

Preferably, the first internal heat exchanger 19 can be a coaxial internal heat exchanger with a length between 50 mm and 120 mm while the second internal heat exchanger 19' can be a coaxial internal heat exchanger with a length of between 50 mm and 120 mm. length between 200 mm and 700 mm.

The first refrigerant fluid loop A may also include a dehydrating bottle 14 placed downstream of the bifluid heat exchanger 5, more precisely between said bifluid heat exchanger 5 and the first internal heat exchanger 19. Such a dehydrating bottle 14 placed on the high pressure side of the air conditioning circuit, that is to say downstream of the two-fluid heat exchanger 5 and upstream of an expansion device, has a smaller footprint as well as a reduced cost compared to other phase separation solutions such as an accumulator which would be placed on the low pressure side of the air conditioning circuit, that is to say upstream of the compressor 3, in particular upstream of the first internal heat exchanger 19.

The first 7, second 11, third 17 and fourth 77 expansion devices can be electronic expansion valves, i.e. the pressure of the refrigerant fluid at the outlet is controlled by an actuator which fixes the opening section of the expansion device , thus fixing the pressure of the fluid at the outlet. Such an electronic expansion valve is in particular capable of allowing the coolant to pass without loss of pressure when said expansion device is completely open.

According to a preferred embodiment, the first expansion device 7 is an electronic expansion valve that can be controlled by a control unit integrated into the vehicle and the second expansion device 11 is a thermostatic expansion valve.

The second expansion device 11 may in particular be a thermostatic expansion valve incorporating a shutdown function. In this case, said first 7 and second 11 expansion devices can be bypassed by a bypass pipe A', comprising in particular a stop valve 25, as illustrated in FIG. 4. This bypass pipe A' allows the refrigerant to bypass said first 7 and second 11 expansion devices without suffering a loss of pressure. Preferably, at least the second expansion device 11 is a thermostatic expansion valve comprising a bypass line A'. The first expansion device 7 can also include a stop function or else include a stop valve downstream in order to block or not the passage of the refrigerant fluid.

The first refrigerant fluid loop A also includes a second bypass line 40 for the first expansion device 7 and the first heat exchanger 9. This second bypass line 40 includes a third expansion device 17 arranged upstream of a first cooler 15. This first cooler 15 can be arranged jointly on a secondary thermal management loop. The secondary thermal management loop can more particularly be a loop in which a heat transfer fluid circulates and connected to heat exchangers or cold plates at the level of batteries and/or electronic elements. The first cooler 15 can also be a heat exchanger directly in contact with the elements to be cooled, such as the batteries.

The third expansion device 17 can be an electronic expansion valve, that is to say the pressure of the refrigerant fluid at the outlet is controlled by an actuator which fixes the opening section of the expansion device, thus fixing the pressure of the fluid at the outlet. . Such an electronic expansion valve is in particular capable of allowing the coolant to pass without loss of pressure when said expansion device is completely open.

The third expansion device 17 can also comprise a stop function in order to allow the refrigerant fluid to pass through the second bypass pipe 40 or not. An alternative is to place a stop valve on the second bypass pipe 40, in upstream of the third expansion device 17.

The second bypass pipe 40 is connected on the one hand upstream of the first expansion device 7. This connection is made at the level of a third connection point 41 disposed upstream of the first expansion device 7, between the second heat exchanger heat 19' and said first expansion device 7.

According to a first embodiment illustrated in Figure 1, the second bypass pipe 40 is connected on the other hand to the first bypass pipe 30, upstream of the first shut-off valve 33 and the second internal heat exchanger 19 '. This connection is made at a fourth connection point 42 arranged between the first connection point 31 and the first shut-off valve 33 when the latter is arranged upstream of the second internal heat exchanger 19' as in the figure 1.

According to a second embodiment illustrated in Figure 2, the second bypass pipe 40 is connected on the other hand on the first bypass pipe 30, upstream of the second heat exchanger 19 'and downstream of the first valve of stop 33. The fourth connection point 42 is then placed between the first stop valve 33 and the second heat exchanger 19' when the first stop valve 33 is placed upstream of the second internal heat exchanger 19' as on Figure 2.

FIG. 3 shows a third embodiment where the second bypass pipe 40 is connected on the one hand upstream of the first expansion device 7 and on the other hand downstream of the second expansion device 19', between said second expansion device expansion 19' and the first internal heat exchanger 19. The third connection point 41 is thus also arranged upstream of the first expansion device 7, between the second heat exchanger 19' and said first expansion device 7.

In the example of Figure 3, the fourth connection point 42 is arranged downstream of the first bypass line 30, between the second connection point 32 and the first internal heat exchanger 19. However, it is also quite possible to imagine that the fourth connection point 42 is arranged on the first bypass line 30, downstream of the first shut-off valve 33 and of the second internal heat exchanger 19'.

The first refrigerant fluid loop A also includes a third bypass line 70. This third bypass line 70 includes a fourth expansion device 77 arranged upstream of a second cooler 75. This second cooler 75 can also be arranged jointly on a secondary thermal management loop. The secondary thermal management loop can more particularly be a loop in which a heat transfer fluid circulates and connected to heat exchangers or cold plates at the level of batteries and/or electronic elements. The second cooler 75 can also be a heat exchanger directly in contact with the elements to be cooled, such as the batteries.

The fourth expansion device 77 can also comprise a stop function in order to allow the refrigerant fluid to pass through the third bypass pipe 70 or not. An alternative is to place a stop valve on the second bypass pipe, upstream of the fourth expansion device 77.

The fourth expansion device 77 can be a thermostatic expansion valve whose thermostatic bulb is positioned at the outlet of the second cooling 75. The fourth expansion device 77 can also be an electronic expansion valve controlled by an electronic control unit.

The third bypass line 70 is connected on the one hand upstream of the first expansion device 7. This connection is made at the level of a fifth connection point 71 disposed upstream of the first expansion device 7, between the first point of connection 31 of the first bypass pipe 30 and said first expansion device 7. The third bypass pipe 70 is connected on the other hand downstream of the second heat exchanger 13. This connection is made at the level of a sixth point of connection 72 arranged downstream of the second heat exchanger 13, between said second heat exchanger 13 and the second connection point 32 of the first bypass pipe 30, more precisely downstream of the non-return valve 23.

The second heat transfer fluid loop B can comprise: the two-fluid heat exchanger 5,
- a first heat transfer fluid circulation pipe 50 comprising a third heat exchanger 54 intended to be crossed by a flow of interior air 100 to the motor vehicle, and connecting a first junction point 61 arranged downstream of the heat exchanger bifluid 5 and a second junction point 62 arranged upstream of the bifluid heat exchanger 5,
- a second heat transfer fluid circulation pipe 60 comprising a fourth heat exchanger 64 intended to be traversed by a flow of air 200 outside the motor vehicle, and connecting the first junction point 61 disposed downstream of the heat exchanger bifluid 5 and the second junction point 62 arranged upstream of the bifluid heat exchanger 5, and
- a pump 18 arranged downstream or upstream of the two-fluid heat exchanger 5, between the first junction point 61 and the second junction point 62.

The indirect reversible air conditioning circuit 1 comprises within the second heat transfer fluid loop B a device for redirecting the heat transfer fluid coming from the two-fluid heat exchanger 5 to the first circulation pipe 50 and/or to the second heat transfer pipe. circulation 60.

As illustrated in FIGS. 1 to 3, said device for redirecting the coolant coming from the two-fluid heat exchanger 5 may in particular comprise a fourth shut-off valve 63 arranged on the second circulation pipe 60 in order to block or not the heat transfer fluid and to prevent it from circulating in said second circulation pipe 60.

The indirect reversible air conditioning circuit 1 may also include a shutter 310 for obstructing the interior air flow 100 passing through the third heat exchanger 54.

This embodiment makes it possible in particular to limit the number of valves on the second heat transfer fluid loop B and thus makes it possible to limit production costs.

According to an alternative embodiment illustrated in FIG. 5, the device for redirecting the heat transfer fluid coming from the two-fluid heat exchanger 5 may in particular comprise:
- a fourth shut-off valve 63 arranged on the second circulation pipe 60 in order to block or not the heat transfer fluid and to prevent it from circulating in the said second circulation pipe 60, and
- a fifth shut-off valve 53 arranged on the first circulation pipe 50 in order to block or not the heat transfer fluid and prevent it from circulating in the said first circulation pipe 50.

The second loop of heat transfer fluid B may also include an electric heating element 55 of the heat transfer fluid. Said electrical heating element 55 is arranged in particular, in the direction of circulation of the heat transfer fluid, downstream of the bifluid heat exchanger 5, between said bifluid heat exchanger 5 and the first junction point 61.

The present invention also relates to various modes of operation of the indirect reversible air conditioning circuit 1, illustrated in FIGS. 6 to 10. In these FIGS. 6 to 10, only the elements in which the refrigerant fluid and/or the heat transfer fluid circulate are represented. The direction of circulation of the refrigerant fluid and/or of the heat transfer fluid is represented by arrows.

1. first cooling mode:

Figure 6 shows a first cooling mode in which, at the level of the first refrigerant fluid loop A, the refrigerant fluid circulates successively in:
- the compressor 3 where the refrigerant passes at high pressure,
- the two-fluid heat exchanger 5, at which the refrigerant fluid yields heat energy to the heat transfer fluid of the second heat transfer fluid loop B,
- the first internal heat exchanger 19,
- the second internal heat exchanger 19',
- a first part of the refrigerant fluid passes through the second bypass line 40, passes into the third expansion device 17 where it undergoes a loss of pressure and passes to low pressure, said low pressure refrigerant fluid then circulates in the first cooler 15 ,
- a second part of the refrigerant fluid passes into the first expansion device 7, where it undergoes a loss of pressure and passes at low pressure, the first heat exchanger 9, at the level of which it captures calorific energy from the flow of internal air 100 cooling the latter, and in the first bypass pipe 30.

The two parts of refrigerant fluid join at the level of the first bypass line 30 upstream of the second internal heat exchanger 19' in the example of FIG. 6. The refrigerant fluid then passes into the second internal heat exchanger 19' , and the first internal heat exchanger 19 before returning to the compressor 3.

Whatever the embodiment of the connection of the second bypass pipe 40 illustrated by FIGS. 1 to 3, the two parts of the refrigerant fluid come together upstream of the first internal heat exchanger 19. The refrigerant fluid thus passes at least by the first internal heat exchanger 19 before joining the compressor 3.

At the level of the second heat transfer fluid loop B, the heat transfer fluid leaving the two-fluid heat exchanger 5 circulates in the fourth heat exchanger 64 of the second circulation pipe 50.

As illustrated by FIG. 6, a portion of the heat transfer fluid at the outlet of the two-fluid heat exchanger 5 circulates in the third heat exchanger 54 of the first circulation pipe 50 and another portion of the heat transfer fluid at the outlet of the exchanger bifluid heat 5 circulates in the fourth heat exchanger 64 of the second circulation pipe 50. The obstruction flap 310 is closed so as to prevent the interior air flow 100 from circulating in the third heat exchanger 54.

The refrigerant at the inlet of the compressor 3 is in the gaseous phase. The refrigerant fluid undergoes compression while passing through the compressor 3. Said refrigerant fluid is then said to be at high pressure.

The high-pressure refrigerant fluid passes through the two-fluid heat exchanger 5 and undergoes a loss of heat energy due to its passage into the liquid phase and the transfer of this heat energy to the heat transfer fluid of the second heat transfer fluid loop B. The high-pressure refrigerant fluid then loses heat energy while remaining at a constant pressure.

The high pressure refrigerant fluid then passes through the first internal heat exchanger 19 where it loses heat energy. This calorific energy is transferred to the low-pressure refrigerant from the first bypass line 30.

The high-pressure refrigerant fluid then passes through the second internal heat exchanger 19' where it again loses heat energy. This heat energy is transferred to the low-pressure refrigerant fluid passing through the first bypass line 30.

At the outlet of the second internal heat exchanger 19', a first part of the refrigerant fluid passes into the second bypass line 40 and a second part of the refrigerant fluid goes to the first expansion device 7.

The first part of the refrigerant fluid passes into the third expansion device 17. The high pressure refrigerant fluid undergoes a loss of isenthalpic pressure and passes into a state of two-phase mixing. The refrigerant fluid is now said to be at low pressure.

The low-pressure refrigerant fluid then passes into the first cooler 15 where it gains calorific energy at the first cooler 15. The refrigerant fluid returns to the gaseous state. At the outlet of the first cooler 15, the refrigerant fluid joins the first bypass pipe 30. In the example illustrated in FIG. 6, the refrigerant fluid joins the first bypass pipe 30 upstream of the first shut-off valve 33 and of the second internal heat exchanger 19'.

At the outlet of the second internal heat exchanger 19', a second part of the high-pressure refrigerant fluid passes into the first expansion device 7. The high-pressure refrigerant fluid undergoes a loss of isenthalpic pressure and passes into a state of two-phase mixing. The refrigerant fluid is now said to be at low pressure.

The low-pressure refrigerant fluid then passes through the first heat exchanger 9 where it gains calorific energy by cooling the interior air flow 100. The refrigerant fluid returns to the gaseous state. At the outlet of the first heat exchanger 9, the refrigerant fluid is redirected to the first bypass line 30. So that the refrigerant fluid does not pass into the second heat exchanger 13, the second expansion device 11 is closed. Similarly, so that the refrigerant fluid does not cross into the third bypass line 70 and the second cooler 75, the fourth expansion device 77 is closed.

The low-pressure refrigerant from both the first heat exchanger 9 and the second bypass line 40 then passes into the second internal heat exchanger 19' where it gains heat energy from the high-pressure refrigerant. passing through the second internal heat exchanger 19'.

The low pressure refrigerant fluid then passes into the first internal heat exchanger 19 where it again gains heat energy from the high pressure refrigerant fluid passing through the first internal heat exchanger 19. The low pressure refrigerant fluid then returns to compressor 3.

This first cooling mode is useful for cooling the interior air flow 100 as well as for cooling the elements such as batteries and/or electronic elements cooled directly or indirectly by the first cooler 15.

In this first mode of cooling, the two internal heat exchangers 19 and 19' are active both for the refrigerant fluid coming from the first heat exchanger 9 and the refrigerant fluid passing through the second bypass pipe 40, and their effects are add up. The use of the internal heat exchangers 19 and 19' one after the other makes it possible to reduce the calorific energy of the refrigerant fluid at the inlet of the first expansion device 7. The refrigerant fluid in the liquid state at the outlet of the two-fluid heat exchanger 5 is cooled by the refrigerant fluid in the gaseous state and at low pressure leaving the first heat exchanger 9 and the first cooler 15. The difference in calorific energy at the terminals of these two heat exchangers increases substantially which allows both, an increase in the cooling power available at said first heat exchanger 9 and the first cooler 15 and this therefore leads to an improvement in the coefficient of performance (or COP for "coefficient of performance").

In addition, the addition of calorific energy to the low-pressure refrigerant fluid at the first 19 and second 19' internal heat exchangers makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3, in particular when the air conditioning circuit 1 comprises a dehydrating bottle 14 placed downstream of the two-fluid heat exchanger 5.

At the level of the second heat transfer fluid loop B, the heat transfer fluid gains calorific energy from the refrigerant at the level of the two-fluid heat exchanger 5.

As illustrated in the example of FIG. 6, a portion of the heat transfer fluid circulates in the first circulation pipe 50 and passes through the third heat exchanger 54. The heat transfer fluid does not, however, lose heat energy because the obstruction flap 310 is closed and blocks the flow of interior air 100 so that it does not pass through the third heat exchanger 54.

Another portion of the heat transfer fluid circulates in the second circulation pipe 60 and passes through the fourth heat exchanger 64. The heat transfer fluid loses calorific energy at the level of said fourth heat exchanger 64 by releasing it into the flow of outside air. 200. The fourth stop valve 63 is open to allow passage of the heat transfer fluid.

An alternative solution (not shown) so that the heat transfer fluid does not exchange with the interior air flow 100 at the level of the third heat exchanger 54, is to provide, as in FIG. 5, the first circulation pipe 50 with the fifth shut-off valve 53 and to close it so as to prevent the heat transfer fluid from circulating in the said first circulation line 50.

2. second cooling mode:

Figure 7 shows a second cooling mode in which, at the level of the first refrigerant fluid loop A, the refrigerant fluid circulates successively in:
- the compressor 3 where the refrigerant passes at high pressure,
- the two-fluid heat exchanger 5, at which the refrigerant fluid yields heat energy to the heat transfer fluid of the second heat transfer fluid loop B,
-the first internal heat exchanger 19,
-the second internal heat exchanger 19',
-a first part of the refrigerant passes through the second bypass pipe 40, passes into the third expansion device 17 where it undergoes a loss of pressure and passes to low pressure, said low pressure refrigerant then circulates in the first cooler 15, the first bypass pipe 30 and the second internal heat exchanger 19',
- a second part of the refrigerant fluid passes into the first expansion device 7, where it undergoes a first loss of pressure and passes to intermediate pressure, the first heat exchanger 9 which it passes through without loss of heat, the third bypass pipe 70, the fourth expansion device 77 where it undergoes a second loss of pressure and switches to low pressure and the second cooler 75.

The two parts of refrigerant fluid join upstream of the first internal heat exchanger 19 in the example of Figure 7. The refrigerant fluid then passes through the first internal heat exchanger 19 before returning to the compressor 3.

Whatever the embodiment of the connection of the second bypass pipe 40 illustrated by FIGS. 1 to 3, the two parts of the refrigerant fluid come together upstream of the first internal heat exchanger 19. The refrigerant fluid coming from the first cooler 15 thus passes at least through the first internal heat exchanger 19 before joining the compressor 3.

By intermediate pressure is meant here a pressure located between the low pressure of the refrigerant fluid when it enters the compressor 3 and the high pressure of the refrigerant fluid at the outlet of said compressor 3.

At the level of the second heat transfer fluid loop B, the heat transfer fluid leaving the two-fluid heat exchanger 5 circulates in the fourth heat exchanger 64 of the second circulation pipe 50.

As illustrated by FIG. 7, a portion of the heat transfer fluid at the outlet of the two-fluid heat exchanger 5 circulates in the third heat exchanger 54 of the first circulation pipe 50 and another portion of the heat transfer fluid at the outlet of the exchanger bifluid heat 5 circulates in the fourth heat exchanger 64 of the second circulation pipe 50. The obstruction flap 310 is closed so as to prevent the interior air flow 100 from circulating in the third heat exchanger 54.

The refrigerant at the inlet of the compressor 3 is in the gaseous phase. The refrigerant fluid undergoes compression while passing through the compressor 3. Said refrigerant fluid is then said to be at high pressure.

The high-pressure refrigerant fluid passes through the two-fluid heat exchanger 5 and undergoes a loss of heat energy due to its passage into the liquid phase and the transfer of this heat energy to the heat transfer fluid of the second heat transfer fluid loop B. The high-pressure refrigerant fluid then loses heat energy while remaining at a constant pressure.

The high pressure refrigerant fluid then passes through the first internal heat exchanger 19 where it loses heat energy. This calorific energy is transferred to the low-pressure refrigerant coming from the first bypass pipe 30 and from the third bypass pipe 70.

The high-pressure refrigerant fluid then passes through the second internal heat exchanger 19' where it again loses heat energy. This heat energy is transferred to the low-pressure refrigerant fluid passing through the first bypass line 30.

At the outlet of the second internal heat exchanger 19', a first part of the refrigerant fluid passes into the second bypass line 40 and a second part of the refrigerant fluid goes to the first expansion device 7.

The first part of the refrigerant fluid passes into the third expansion device 17. The high pressure refrigerant fluid undergoes a loss of isenthalpic pressure and passes into a state of two-phase mixing. The refrigerant fluid is now said to be at low pressure.

The low-pressure refrigerant fluid then passes through the first cooler 15 where it gains heat energy. The refrigerant fluid returns to the gaseous state. At the outlet of the first cooler 15, the refrigerant fluid joins the first bypass pipe 30. In the example illustrated in FIG. 7, the refrigerant fluid joins the first bypass pipe 30 upstream of the first shut-off valve 33 and of the second internal heat exchanger 19'.

The low-pressure refrigerant from the second bypass line 40 then passes into the second internal heat exchanger 19' where it gains heat energy from the high-pressure refrigerant passing through the second internal heat exchanger 19'.

At the outlet of the second internal heat exchanger 19', a second part of the high-pressure refrigerant fluid passes into the first expansion device 7. The high-pressure refrigerant fluid undergoes a first loss of isenthalpic pressure and passes into a two-phase mixture state. . The refrigerant fluid is now said to be at intermediate pressure.

The low-pressure refrigerant fluid then passes into the first heat exchanger 9 which it passes through without loss of heat energy. For this, the internal air flow 100 can be stopped and thus the exchanges of calorific energy are limited at the level of the first heat exchanger 9. The fact of subjecting the refrigerant fluid to a first loss of pressure makes it possible to avoid that the refrigerant fluid passing through the first heat exchanger 9 is at high pressure, which could damage said first heat exchanger 9.

At the outlet of the first heat exchanger 9, the coolant is redirected to the third bypass pipe 70. So that the coolant does not pass into the second heat exchanger 13 or into the first bypass pipe 30, the second device expansion valve 11 and the first shut-off valve 33 are closed.

The refrigerant fluid then passes into the fourth expansion device 77 at which it undergoes a second part of pressure and passes to low pressure. The low pressure refrigerant fluid then passes through the second cooler 75 where it gains heat energy. The refrigerant fluid returns to the gaseous state.

The two parts of low-pressure refrigerant fluid come together upstream of the first expansion device 19. The low-pressure refrigerant fluid then passes into the first internal heat exchanger 19 where it again gains calorific energy from the refrigerant fluid. at high pressure passing through the first internal heat exchanger 19. The low pressure refrigerant fluid then returns to the compressor 3.

This second cooling mode is useful for cooling elements such as batteries and/or electronic elements cooled directly or indirectly by the first cooler 15. This is particularly so when it is necessary to absorb a large quantity of heat energy, for example when rapidly charging or discharging the batteries.

In this second cooling mode, the two internal heat exchangers 19 and 19' are active both for the refrigerant fluid coming from the first heat exchanger 9 and the refrigerant fluid passing through the second bypass line 40, and their effects are add up. The use of the internal heat exchangers 19 and 19' one after the other makes it possible to reduce the calorific energy of the refrigerant fluid at the inlet of the first expansion device 7. The refrigerant fluid in the liquid state at the outlet of the two-fluid heat exchanger 5 is cooled by the refrigerant fluid in the gaseous state and at low pressure leaving the first cooler 15. The difference in calorific energy at the terminals of these two heat exchangers increases substantially, which allows both , an increase in the cooling power available at the level of the first cooler 15 and this therefore leads to an improvement in the coefficient of performance (or COP for “coefficient of performance”).

In addition, the addition of calorific energy to the low-pressure refrigerant fluid at the first 19 and second 19' internal heat exchangers makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3, in particular when the air conditioning circuit 1 comprises a dehydrating bottle 14 placed downstream of the two-fluid heat exchanger 5.

At the level of the second heat transfer fluid loop B, the heat transfer fluid gains calorific energy from the refrigerant at the level of the two-fluid heat exchanger 5.

As illustrated in the example of FIG. 7, a portion of the heat transfer fluid circulates in the first circulation pipe 50 and passes through the third heat exchanger 54. The heat transfer fluid does not, however, lose heat energy because the obstruction flap 310 is closed and blocks the flow of interior air 100 so that it does not pass through the third heat exchanger 54.

Another portion of the heat transfer fluid circulates in the second circulation pipe 60 and passes through the fourth heat exchanger 64. The heat transfer fluid loses calorific energy at the level of said fourth heat exchanger 64 by releasing it into the flow of outside air. 200. The fourth stop valve 63 is open to allow passage of the heat transfer fluid.

An alternative solution (not shown) so that the heat transfer fluid does not exchange with the interior air flow 100 at the level of the third heat exchanger 54, is to provide, as in FIG. 5, the first circulation pipe 50 with the fifth shut-off valve 53 and to close it so as to prevent the heat transfer fluid from circulating in the said first circulation pipe 50.

3. first heat pump mode:

Figure 8 shows a first heat pump mode in which, at the level of the first refrigerant fluid loop A, the refrigerant fluid circulates successively in:
- the compressor 3 where said refrigerant passes at high pressure,
- the two-fluid heat exchanger 5, at which the refrigerant fluid yields heat energy to the heat transfer fluid of the second heat transfer fluid loop B,
- the first internal heat exchanger 19,
- the second internal heat exchanger 19',
- the first expansion device 7 where said refrigerant passes to an intermediate pressure,
- the first heat exchanger 9,
- the second expansion device 11 where said refrigerant passes at low pressure,
- the second heat exchanger 13 and then into the first internal heat exchanger 19 before returning to the compressor 3.

The heat transfer fluid leaving the first two-fluid heat exchanger 5 circulates only in the third heat exchanger 54 of the first circulation line 50.

The refrigerant at the inlet of the compressor 3 is in the gaseous phase. The refrigerant fluid undergoes compression while passing through the compressor 3. Said refrigerant fluid is then said to be at high pressure.

The high-pressure refrigerant fluid passes through the first two-fluid heat exchanger 5 and undergoes a loss of heat energy due to its passage into the liquid phase and the transfer of heat energy to the heat transfer fluid of the second heat transfer fluid loop B. The high-pressure refrigerant fluid then loses heat energy while remaining at a constant pressure.

The high pressure refrigerant fluid then passes through the first internal heat exchanger 19 where it loses heat energy. This calorific energy is transferred to the low-pressure refrigerant fluid coming from the second heat exchanger 13.

The high pressure refrigerant fluid then passes into the second internal heat exchanger 19 'where it does not lose heat energy because there is no circulation of low pressure refrigerant fluid in said second internal heat exchanger 19' .

As illustrated in FIG. 8, at the outlet of the second internal heat exchanger 19', the refrigerant fluid does not circulate in the second bypass line 40 because the third expansion device 17 is closed.

The high-pressure refrigerant fluid then passes through the first expansion device 7. The refrigerant fluid undergoes a first loss of isenthalpic pressure which causes it to pass into a two-phase mixture state. The refrigerant is now at an intermediate pressure.

The refrigerant fluid then passes through the first heat exchanger 9 where it loses heat energy by heating the interior air flow 100.

At the outlet of the first heat exchanger 9, the refrigerant is redirected to the second heat exchanger 13. For this, the first shut-off valve 33 of the first bypass line 30 and the fourth expansion device 77 are closed. Before arriving at the second heat exchanger 13, the refrigerant passes through the first expansion device 11 where it undergoes a second loss of isenthalpic pressure. The refrigerant is now at low pressure.

The low-pressure refrigerant fluid then passes through the second heat exchanger 13 where it gains calorific energy by absorbing calorific energy from the outside air flow 200. The refrigerant fluid thus returns to the gaseous state.

The low pressure refrigerant fluid then passes into the first internal heat exchanger 19 where it again gains heat energy from the high pressure refrigerant fluid passing through the first internal heat exchanger 19. The low pressure refrigerant fluid then returns to compressor 3.

In this first heat pump mode, only the first internal heat exchanger 19 is active. Because the calorific energy of the low-pressure refrigerant at the inlet of the compressor 3 is greater, the calorific energy of the high-pressure refrigerant at the outlet of the compressor 3 will also be greater than the calorific energy of the refrigerant when there is no internal heat exchanger.

In addition, the addition of calorific energy to the low-pressure refrigerant fluid at the first internal heat exchanger 19 makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3, in particular when the air conditioning circuit 1 includes a dehydrating bottle 14 arranged downstream of the first two-fluid heat exchanger 5. The effect of the first internal heat exchanger 19 is limited because its length is between 50 mm and 120 mm. This size makes it possible to limit the heat exchanges between the high-pressure refrigerant fluid and the low-pressure refrigerant fluid so that the heat energy exchanged makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3 without however penalize the efficiency of the heat pump mode. Indeed, the purpose of this heat pump mode is to release as much heat energy as possible into the interior air flow 100 in order to heat it at the level of the first heat exchanger 9. This heat energy comes, in this first heat pump mode, of the outside air flow 200 via the second heat exchanger 13.

At the level of the second heat transfer fluid loop B, the heat transfer fluid gains calorific energy from the refrigerant fluid at the level of the first two-fluid heat exchanger 5.

As illustrated in FIG. 8, the heat transfer fluid circulates in the first circulation pipe 50 and crosses the third heat exchanger 54. The heat transfer fluid loses calorific energy by heating the internal air flow 100. For this, the obstruction flap 310 is open and/or the fifth shut-off valve 53 is open. The fourth shut-off valve 63 is for its part closed to prevent the passage of the heat transfer fluid into the second circulation pipe 60.

This first heat pump mode is useful for heating the indoor airflow 100 at both the first heat exchanger 9 and the third heat exchanger 54 by absorbing heat energy from the outdoor airflow 200 at the level of the second heat exchanger 13.

In addition, the electric heating element 55 can be in operation in order to provide an additional supply of calorific energy to the heat transfer fluid to heat the interior air flow 100.

4. second heat pump mode:

Figure 9 shows a second heat pump mode in which, at the level of the first refrigerant fluid loop A, the refrigerant fluid circulates successively in:
- the compressor 3 where said refrigerant passes at high pressure,
- the two-fluid heat exchanger 5, at which the refrigerant fluid yields heat energy to the heat transfer fluid of the second heat transfer fluid loop B,
- the first internal heat exchanger 19,
- the second internal heat exchanger 19',
- the first expansion device 7 where said refrigerant passes to an intermediate pressure,
- the first heat exchanger 9,
- a first part of the refrigerant fluid passes through the second expansion device 11 where said refrigerant fluid passes at low pressure and the second heat exchanger 13, a second portion of the refrigerant fluid passes through the third bypass pipe 70, the fourth expansion 77 where said refrigerant passes at low pressure and the second cooler 75.

The two parts of low-pressure refrigerant fluid join together upstream of the first two-fluid heat exchanger 19. The refrigerant fluid passes through said first two-fluid heat exchanger 19 before returning to the compressor 3.

The heat transfer fluid leaving the first two-fluid heat exchanger 5 circulates only in the third heat exchanger 54 of the first circulation line 50.

The refrigerant at the inlet of the compressor 3 is in the gaseous phase. The refrigerant fluid undergoes compression while passing through the compressor 3. Said refrigerant fluid is then said to be at high pressure.

The high-pressure refrigerant fluid passes through the first two-fluid heat exchanger 5 and undergoes a loss of heat energy due to its passage into the liquid phase and the transfer of heat energy to the heat transfer fluid of the second heat transfer fluid loop B. The high-pressure refrigerant fluid then loses heat energy while remaining at a constant pressure.

The high pressure refrigerant fluid then passes through the first internal heat exchanger 19 where it loses heat energy. This calorific energy is transferred to the low-pressure refrigerant fluid coming from the second heat exchanger 13.

The high pressure refrigerant fluid then passes into the second internal heat exchanger 19 'where it does not lose heat energy because there is no circulation of low pressure refrigerant fluid in said second internal heat exchanger 19' .

As illustrated in FIG. 9, at the outlet of the second internal heat exchanger 19', the refrigerant fluid does not circulate in the second bypass line 40 because the third expansion device 17 is closed.

The high-pressure refrigerant fluid then passes through the first expansion device 7. The refrigerant fluid undergoes a first loss of isenthalpic pressure which causes it to pass into a two-phase mixture state. The refrigerant is now at an intermediate pressure.

The refrigerant fluid then passes through the first heat exchanger 9 where it loses heat energy by heating the interior air flow 100.

At the outlet of the first heat exchanger 9, a first part of the refrigerant fluid is redirected to the second heat exchanger 13. For this, the first shut-off valve 33 of the first bypass line 30 is closed. Before arriving at the second heat exchanger 13, the refrigerant passes through the first expansion device 11 where it undergoes a second loss of isenthalpic pressure. The refrigerant is now at low pressure.

The low-pressure refrigerant fluid then passes through the second heat exchanger 13 where it gains calorific energy by absorbing calorific energy from the outside air flow 200. The refrigerant fluid thus returns to the gaseous state.

At the outlet of the first heat exchanger 9, a second part of the refrigerant fluid is redirected to the second cooler 75 of the third bypass pipe 70. For this, the first shut-off valve 33 of the first bypass pipe 30 is closed. . Before arriving at the second cooler 75, the refrigerant fluid passes through the fourth expansion device 77 where it undergoes a second loss of isenthalpic pressure. The refrigerant is now at low pressure.

The low pressure refrigerant fluid then passes through the second cooler 75 where it gains heat energy by absorbing heat energy. The refrigerant thus returns to the gaseous state.

The two parts of the low-pressure refrigerant fluid meet upstream of the first internal heat exchanger 19.

The low pressure refrigerant fluid then passes into the first internal heat exchanger 19 where it again gains heat energy from the high pressure refrigerant fluid passing through the first internal heat exchanger 19. The low pressure refrigerant fluid then returns to compressor 3.

In this second heat pump mode, only the first internal heat exchanger 19 is active. Because the calorific energy of the low-pressure refrigerant at the inlet of the compressor 3 is greater, the calorific energy of the high-pressure refrigerant at the outlet of the compressor 3 will also be greater than the calorific energy of the refrigerant when there is no internal heat exchanger.

In addition, the addition of calorific energy to the low-pressure refrigerant fluid at the first internal heat exchanger 19 makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3, in particular when the air conditioning circuit 1 comprises a dehydrating bottle 14 arranged downstream of the first two-fluid heat exchanger 5. The effect of the first internal heat exchanger 19 is limited because its length is between 50 mm and 120 mm. This size makes it possible to limit the heat exchanges between the high-pressure refrigerant fluid and the low-pressure refrigerant fluid so that the heat energy exchanged makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3 without however penalize the efficiency of the heat pump mode. Indeed, the purpose of this heat pump mode is to release as much heat energy as possible into the interior air flow 100 in order to heat it at the level of the first heat exchanger 9. This heat energy comes, in this second heat pump mode, the flow of outside air 200 through the second heat exchanger 13 and elements such as batteries through the second cooler 75.

At the level of the second heat transfer fluid loop B, the heat transfer fluid gains calorific energy from the refrigerant fluid at the level of the first two-fluid heat exchanger 5.

As illustrated in FIG. 9, the heat transfer fluid circulates in the first circulation pipe 50 and passes through the third heat exchanger 54. The heat transfer fluid loses calorific energy by heating the interior air flow 100. For this, the obstruction flap 310 is open and/or the fifth shut-off valve 53 is open. The fourth shut-off valve 63 is for its part closed to prevent the passage of the heat transfer fluid into the second circulation pipe 60.

This second heat pump mode is useful for heating the interior air flow 100 both at the level of the first heat exchanger 9 and of the third heat exchanger 54 by absorbing calorific energy from the exterior air flow 200 at the level of the second heat exchanger 13 and elements such as the batteries at the level of the second cooler 75.

In addition, the electric heating element 55 can be in operation in order to provide an additional supply of calorific energy to the heat transfer fluid to heat the interior air flow 100.

5. third heat pump mode:

Figure 10 shows a third heat pump mode in which, at the level of the first refrigerant fluid loop A, the refrigerant fluid circulates successively in:
- the compressor 3 where said refrigerant passes at high pressure,
- the two-fluid heat exchanger 5, at which the refrigerant fluid yields heat energy to the heat transfer fluid of the second heat transfer fluid loop B,
- the first internal heat exchanger 19,
- the second internal heat exchanger 19',
- the first expansion device 7 where said refrigerant passes to an intermediate pressure,
- the first heat exchanger 9,
- the fourth expansion device 77 of the third bypass line 70 where said refrigerant fluid passes at low pressure,
- the second cooler 75,
- the first two-fluid heat exchanger 19 before returning to the compressor 3.

The heat transfer fluid leaving the first two-fluid heat exchanger 5 circulates only in the third heat exchanger 54 of the first circulation line 50.

The refrigerant at the inlet of the compressor 3 is in the gaseous phase. The refrigerant fluid undergoes compression while passing through the compressor 3. Said refrigerant fluid is then said to be at high pressure.

The high-pressure refrigerant fluid passes through the first two-fluid heat exchanger 5 and undergoes a loss of heat energy due to its passage into the liquid phase and the transfer of heat energy to the heat transfer fluid of the second heat transfer fluid loop B. The high-pressure refrigerant fluid then loses heat energy while remaining at a constant pressure.

The high pressure refrigerant fluid then passes through the first internal heat exchanger 19 where it loses heat energy. This calorific energy is transferred to the low-pressure refrigerant fluid coming from the second heat exchanger 13.

The high pressure refrigerant fluid then passes into the second internal heat exchanger 19 'where it does not lose heat energy because there is no circulation of low pressure refrigerant fluid in said second internal heat exchanger 19' .

As illustrated in FIG. 10, at the outlet of the second internal heat exchanger 19', the refrigerant fluid does not circulate in the second bypass line 40 because the third expansion device 17 is closed.

The high-pressure refrigerant fluid then passes into the first expansion device 7. The refrigerant fluid undergoes a first loss of isenthalpic pressure which causes it to pass into a two-phase mixture state. The refrigerant is now at an intermediate pressure.

The refrigerant fluid then passes through the first heat exchanger 9 where it loses heat energy by heating the interior air flow 100.

At the outlet of the first heat exchanger 9, the refrigerant fluid is redirected to the second cooler 75 of the third bypass pipe 70. For this, the first shut-off valve 33 of the first bypass pipe 30 and the second trigger 11 are closed. Before arriving at the second cooler 75, the refrigerant fluid passes through the fourth expansion device 77 where it undergoes a second loss of isenthalpic pressure. The refrigerant is now at low pressure.

The low pressure refrigerant fluid then passes through the second cooler 75 where it gains heat energy by absorbing heat energy. The refrigerant thus returns to the gaseous state.

The low pressure refrigerant fluid then passes into the first internal heat exchanger 19 where it again gains heat energy from the high pressure refrigerant fluid passing through the first internal heat exchanger 19. The low pressure refrigerant fluid then returns to compressor 3.

In this third heat pump mode, only the first internal heat exchanger 19 is active. Because the calorific energy of the low-pressure refrigerant at the inlet of the compressor 3 is greater, the calorific energy of the high-pressure refrigerant at the outlet of the compressor 3 will also be greater than the calorific energy of the refrigerant when there is no internal heat exchanger.

In addition, the addition of calorific energy to the low-pressure refrigerant fluid at the first internal heat exchanger 19 makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3, in particular when the air conditioning circuit 1 comprises a dehydrating bottle 14 arranged downstream of the first two-fluid heat exchanger 5. The effect of the first internal heat exchanger 19 is limited because its length is between 50 mm and 120 mm. This size makes it possible to limit the heat exchanges between the high-pressure refrigerant fluid and the low-pressure refrigerant fluid so that the heat energy exchanged makes it possible to limit the proportion of refrigerant fluid in the liquid phase before it enters the compressor 3 without however penalize the efficiency of the heat pump mode. Indeed, the purpose of this heat pump mode is to release as much heat energy as possible into the interior air flow 100 in order to heat it at the level of the first heat exchanger 9. This heat energy comes, in this third heat pump mode, elements such as batteries through the second cooler 75. This makes it possible to recover this energy at low temperature, to close the front face to improve the aerodynamic drag of the vehicle and to avoid icing of the front face , in particular of the fourth heat exchanger 64.

At the level of the second heat transfer fluid loop B, the heat transfer fluid gains calorific energy from the refrigerant fluid at the level of the first two-fluid heat exchanger 5.

As illustrated in FIG. 10, the heat transfer fluid circulates in the first circulation pipe 50 and crosses the third heat exchanger 54. The heat transfer fluid loses calorific energy by heating the internal air flow 100. For this, the obstruction flap 310 is open and/or the fifth shut-off valve 53 is open. The fourth shut-off valve 63 is for its part closed to prevent the passage of the heat transfer fluid into the second circulation pipe 60.

This third heat pump mode is useful for heating the interior air flow 100 both at the level of the first heat exchanger 9 and of the third heat exchanger 54 by absorbing calorific energy from elements such as the batteries at the level of the second cooler 75. This makes it possible to use this energy at low temperature, to close the front face to improve the aerodynamic drag of the vehicle and to avoid icing of the front face, in particular of the fourth heat exchanger 64.

In addition, the electric heating element 55 can be in operation in order to provide an additional supply of calorific energy to the heat transfer fluid to heat the interior air flow 100.

Other operating modes such as defrosting, dehumidification or cooling modes can also be envisaged with such an architecture of the indirect reversible air conditioning circuit 1.

Thus, it is clear that due to its architecture and in particular the presence of the third bypass line 70, the thermal management device can dissipate a greater quantity of heat energy from elements such as batteries. This is particularly useful when high cooling power is required, for example when rapidly charging or discharging the batteries of an electric or hybrid vehicle. In addition, this third bypass duct 70 allows better recovery of heat energy in order to heat the internal air flow 100. Operating modes Fig: Function : 1. first mode of cooling 6 Cooling of the internal air flow 100 via the first heat exchanger 9 and cooling of elements such as batteries via the first cooler 15. Evacuation of heat energy via the fourth heat exchanger 64. 2. second cooling mode 7 Cooling of the internal air flow 100 via the first heat exchanger 9 and cooling of elements such as batteries via the first cooler 15 and the second cooler 75. Evacuation of heat energy via the fourth heat exchanger 64. 3. first heat pump mode 8 Heating of the internal air flow 100 via the first heat exchanger 9 and the third heat exchanger 54. Absorption of heat energy in the external air flow 200 via the second heat exchanger 13. 4. second heat pump mode 9 Heating of the internal air flow 100 via the first heat exchanger 9 and the third heat exchanger 54. Absorption of heat energy in the external air flow 200 via the second heat exchanger 13 and elements such as batteries and/or electric motor and/or electronic components via the second cooler 75. 5. third heat pump mode 10 Heating of the internal air flow 100 via the first heat exchanger 9 and the third heat exchanger 54. Absorption of heat energy from elements such as batteries and/or electric motor and/or electronic components via the second cooler 75 .

Claims (7)

Thermal management device comprising an indirect air conditioning circuit (1) for a motor vehicle comprising:
- a first refrigerant fluid loop (A) in which a refrigerant fluid circulates, said first refrigerant fluid loop (A) comprising, in the direction of circulation of the refrigerant fluid, a compressor (3), a two-fluid heat exchanger (5), a first expansion device (7), a first heat exchanger (9), a second expansion device (11), a second heat exchanger (13) being intended to be crossed by an external air flow (200) to the motor vehicle, and
* a first bypass line (30) of the second heat exchanger (13) comprising a first shut-off valve (33),
* a second bypass pipe (40) for the first expansion device (7) and the first heat exchanger (9), said second bypass pipe (40) comprising a third expansion device (17) arranged upstream of a first cooler (15),
* a third bypass pipe (70) of the second heat exchanger (13), said third bypass pipe (70) comprising a fourth expansion device (77) arranged upstream of a second cooler (75),
* a first internal heat exchanger (19), allowing heat exchange between the high-pressure refrigerant at the outlet of the two-fluid heat exchanger (5) and the low-pressure refrigerant at the outlet of the second heat exchanger ( 13) or the first bypass line (30),
* a second internal heat exchanger (19') allowing heat exchange between the high-pressure refrigerant fluid at the outlet of the first internal heat exchanger (19) and the low-pressure refrigerant fluid flowing in the first bypass line (30 ),
* a second heat transfer fluid loop (B) in which a heat transfer fluid circulates,
the two-fluid heat exchanger (5) being arranged jointly on the one hand on the first refrigerant fluid loop (A) downstream of the compressor (3), between the said compressor (3) and the first expansion device (7), and on the other hand on the second heat transfer fluid loop (B). Thermal management device according to Claim 1, characterized in that the fourth expansion device (77) is a thermostatic expansion valve whose thermostatic bulb is positioned at the outlet of the second cooler (75). Thermal management device according to Claim 1, characterized in that the fourth expansion device (77) is an electronic expansion valve controlled by an electronic control unit. Thermal management device according to one of the preceding claims, characterized in that the second heat transfer fluid loop (B) comprises:
- the two-fluid heat exchanger (5),
- a first heat transfer fluid circulation pipe (50) comprising a third heat exchanger (54) intended to be crossed by an interior air flow (100) to the motor vehicle, and connecting a first junction point (61) arranged downstream of the two-fluid heat exchanger (5) and a second junction point (62) arranged upstream of said two-fluid heat exchanger (5),
- a second heat transfer fluid circulation pipe (60) comprising a fourth heat exchanger (64) intended to be crossed by a flow of air (200) outside the motor vehicle, and connecting the first junction point (61) arranged downstream of the two-fluid heat exchanger (5) and the second junction point (62) disposed upstream of said two-fluid heat exchanger (5), and
- a pump (18) disposed downstream or upstream of the two-fluid heat exchanger (5), between the first junction point (61) and the second junction point (62). Thermal management device according to Claim 4, characterized in that it is configured to operate in a cooling mode in which the refrigerant fluid circulates in the first refrigerant fluid loop (A) successively in:
- the compressor (3) where the refrigerant passes at high pressure,
- the two-fluid heat exchanger (5), at which the refrigerant fluid transfers heat energy to the heat transfer fluid of the second heat transfer fluid loop (B),
- the first internal heat exchanger (19),
- the second internal heat exchanger (19'),
- a first part of the refrigerant fluid passes through the second bypass line (40), passes into the third expansion device (17) where it undergoes a loss of pressure and passes to low pressure, said low pressure refrigerant fluid then circulates in the first cooler (15), the first bypass line (30) and the second internal heat exchanger (19'),
- a second part of the refrigerant fluid passes into the first expansion device (7), where it undergoes a first loss of pressure and passes to intermediate low, the first heat exchanger (9) which it passes through without loss of heat, the third bypass line (70), the fourth expansion device (77) where it undergoes a second loss of pressure and switches to low pressure and the second cooler (75),
the two parts of refrigerant fluid joining upstream of the first internal heat exchanger (19), the refrigerant fluid passing through said first two-fluid heat exchanger (19) before returning to the compressor (3),
at the level of the second heat transfer fluid loop (B), the heat transfer fluid leaving the two-fluid heat exchanger (5) circulating in the fourth heat exchanger (64) of the second circulation line (50). Thermal management device according to Claim 4, characterized in that it is configured to operate in a heat pump mode in which the refrigerant fluid circulates in the first refrigerant fluid loop (A) successively in:
- the compressor (3) where said refrigerant passes at high pressure,
- the two-fluid heat exchanger (5), at which the refrigerant fluid transfers heat energy to the heat transfer fluid of the second heat transfer fluid loop (B),
- the first internal heat exchanger (19),
- the second internal heat exchanger (19'),
- the first expansion device (7) where said refrigerant passes to an intermediate pressure,
- the first heat exchanger (9),
- a first part of the refrigerant fluid passes through the second expansion device (11) where said refrigerant fluid passes at low pressure and the second heat exchanger (13),
- a second part of the refrigerant fluid passes through the third bypass pipe (70), the fourth expansion device (77) where said refrigerant fluid passes at low pressure and the second cooler (75),
the two parts of low-pressure refrigerant fluid joining upstream of the first two-fluid heat exchanger (19), the refrigerant passing through said first two-fluid heat exchanger (19) before returning to the compressor (3),
at the level of the second heat transfer fluid loop (B), the heat transfer fluid leaving the first two-fluid heat exchanger (5) circulating only in the third heat exchanger (54) of the first circulation line (50). Thermal management device according to Claim 4, characterized in that it is configured to operate in another heat pump mode in which the refrigerant fluid circulates in the first refrigerant fluid loop (A) successively in:
- the compressor (3) where said refrigerant passes at high pressure,
- the two-fluid heat exchanger (5), at which the refrigerant fluid transfers heat energy to the heat transfer fluid of the second heat transfer fluid loop (B),
- the first internal heat exchanger (19),
- the second internal heat exchanger (19'),
- the first expansion device (7) where said refrigerant passes to an intermediate pressure,
- the first heat exchanger (9),
- the fourth expansion device (77) of the third bypass pipe (70) where said refrigerant fluid passes at low pressure,
- the second cooler (75),
- the first two-fluid heat exchanger (19) before returning to the compressor (3),
- at the level of the second heat transfer fluid loop (B), the heat transfer fluid leaving the first two-fluid heat exchanger (5) circulating only in the third heat exchanger (54) of the first circulation line (50).