FR3083852A1 - THERMAL MANAGEMENT CIRCUIT OF AN ELECTRIC OR HYBRID VEHICLE - Google Patents

Abstract

The present invention relates to a thermal management circuit of an electric or hybrid motor vehicle in which a coolant circulates, said thermal management circuit comprising a main loop comprising: • a compressor comprising at least two compression stages, • a first exchanger heat intended to be traversed by an external air flow, • a first expansion device, and • a second heat exchanger intended to be in relation to the batteries of the motor vehicle, the coolant outlet of said second heat exchanger being connected to the first compression stage of the compressor, • said thermal management circuit comprising a first circulation branch connected to another compression stage of the compressor, and comprising in the direction of circulation of the refrigerant: • a second expansion device, and • a third heat exchanger allowing the s heat exchanges with an internal air flow, said thermal management circuit comprising a second circulation branch, said second circulation branch comprising in the direction of circulation of the refrigerant: • a third expansion device, and • a fourth heat exchanger intended to be traversed by the internal air flow.

Description

The present invention relates to the field of thermal management circuits for vehicles, in particular for motor vehicles, and more particularly, the present invention relates to thermal management circuits allowing thermal regulation of an electrical storage device intended for electric motor vehicles or hybrids.

These vehicles, whether fully electric or hybrid, that is to say combining the use of a heat engine and an electric motor, require a substantial supply of electrical energy and are equipped with storage devices. electric or batteries. These batteries can not function well outside of a determined temperature range, generally around 45 ° C. Outside this temperature range, the functioning of the batteries as well as its lifespan can be reduced. In addition, above this temperature range, the batteries can reach high temperatures at which it can deteriorate. This is particularly the case when charging the batteries.

It is thus known to use a refrigerant circuit, also used to heat or cool different zones or different components of the vehicle, to cool or heat the batteries as needed and bring them and keep them close to their optimal operating temperature. .

For example, the refrigerant circuit may be sufficient to cool the batteries during a conventional charging phase of the vehicle's electrical storage device, namely a charging phase carried out by connecting the vehicle for several hours to the network. domestic electric. This charging technique keeps the temperature of the electrical storage device below a certain threshold, which makes it possible to reduce the dimensions of the thermal management circuit of the electrical storage device, in particular for its cooling.

However, a new rapid charging technique has appeared recently. It consists in charging the electrical storage device under a high voltage and amperage, so as to charge the electrical storage device in a time reduced by a few tens of minutes. However, this rapid charge implies a significant heating of the electrical storage device due to a Joule effect as well as exothermic chemical reactions which imposes a larger dimensioning of the heat exchanger (s) intended for thermal regulation of the device. electrical storage. In addition, the cooling power generated and necessary to cool the batteries during rapid charging is problematic when it is also desired to have joint cooling of the passenger compartment of the motor vehicle, in particular from a point of view of the different temperatures d evaporation of the refrigerant at the batteries and the heat exchanger used to cool the passenger compartment.

The present invention proposes to at least partially resolve the drawbacks of the prior art and proposes a thermal management circuit as well as operating modes allowing joint cooling of the passenger compartment and the batteries, in particular during rapid charging.

The present invention therefore relates to a thermal management circuit of an electric or hybrid motor vehicle in which a coolant circulates, said thermal management circuit comprising a main loop comprising in the direction of circulation of the coolant:

° a compressor comprising at least two compression stages, ° a first heat exchanger intended to be traversed by an external air flow, ° a first expansion device, and ° a second heat exchanger intended to be in relation to the batteries of the electric or hybrid motor vehicle, the coolant outlet of said second heat exchanger being connected to the first compression stage of the compressor, said thermal management circuit comprising a first circulation branch connecting a first junction point arranged downstream of the first heat exchanger, between said first heat exchanger and the first expansion device, at a compression stage of the compressor different from its first stage, said first circulation branch comprising in the direction of circulation of the refrigerant:

° a second expansion device, and ° a third heat exchanger allowing the heat exchanges with an internal air flow, said thermal management circuit comprising a second circulation branch connecting a second junction point arranged downstream of the first point junction, between said first junction point and the first expansion device, at a third junction point arranged downstream of the second heat exchanger, between said second heat exchanger and the first compression stage of the compressor, said second branch of circulation comprising in the direction of circulation of the refrigerant:

° a third expansion device, and ° a fourth heat exchanger intended to be traversed by the internal air flow.

According to one aspect of the invention, the third heat exchanger can be a two-fluid heat exchanger disposed jointly on the first circulation branch and on a circulation loop of a heat-transfer fluid, said circulation loop possibly comprising a pump, said third heat exchanger and a fifth heat exchanger intended to be traversed by the internal air flow.

According to another aspect of the invention, the third heat exchanger can be intended to be traversed by the internal air flow.

According to another aspect of the invention, the fourth heat exchanger may further comprise a phase change material.

According to another aspect of the invention, the thermal management circuit may also include an internal heat exchanger allowing the heat exchanges between the refrigerant leaving the second expansion device and the refrigerant circulating between the first and the second. junction point.

According to another aspect of the invention, the thermal management circuit can be configured in a first operating mode in which the coolant circulates in:

° the compressor, ° the first heat exchanger at which it loses heat, ° a first part of the refrigerant passes through the main loop and passes through the first expansion device at which the refrigerant passes at a low pressure, the refrigerant then passing through the second heat exchanger at which it absorbs heat before reaching the first compression stage of the compressor, ° a second part of the refrigerant passes through the first circulation branch and passes through the second expansion device at which the refrigerant passes to an intermediate pressure, higher than the low pressure, the refrigerant then crosses the third heat exchanger at which it absorbs heat before joining the second compression stage of the compressor.

According to another aspect of the invention, the thermal management circuit can be configured in a second operating mode in which the coolant circulates in:

° the compressor, ° the first heat exchanger at which it loses heat, ° a first part of the refrigerant passes through the first circulation branch and passes through the second expansion device at which the refrigerant passes to a pressure intermediate, the refrigerant then passes through the third heat exchanger at which it absorbs heat before reaching the second compression stage of the compressor, ° a second part of the refrigerant passes through the first expansion device at which the fluid refrigerant passes at a low pressure, lower than the intermediate pressure, the refrigerant then crosses the second heat exchanger at which it absorbs heat before reaching the first compression stage of the compressor, ° a third part of the refrigerant passes through the second branch of traffic and cross se the third expansion device at which the refrigerant passes to the low pressure, the refrigerant then crosses the fourth heat exchanger at which it absorbs heat before joining the first compression stage of the compressor.

According to another aspect of the invention, the thermal management circuit can be configured in a third operating mode in which the coolant circulates in:

° the compressor, ° the first heat exchanger at which it loses heat, ° a first part of the refrigerant passes through the second circulation branch and passes through the third expansion device at which the refrigerant passes to a low pressure, the coolant then passes through the fourth heat exchanger at which it absorbs heat before reaching the first compression stage of the compressor, ° a second part of the coolant passes through the first circulation branch and passes through the second device expansion at which the refrigerant passes to an intermediate pressure, higher than the low pressure, the refrigerant then crosses the third heat exchanger at which it absorbs heat before joining the second compression stage of the compressor.

[Fig.l] shows a schematic view of a thermal management circuit according to a first embodiment.

[Fig.2] shows a schematic view of a thermal management circuit according to a second embodiment.

[Fig.3] shows a schematic view of the thermal management circuit of Figure 2 according to a first mode of operation.

[Fig.4] represents a pressure \ enthalpy diagram of the coolant according to the first operating mode of figure 3.

[Fig.5] shows a schematic view of the thermal management circuit of Figure 2 according to a second mode of operation.

[Fig.6] shows a pressure \ enthalpy diagram of the refrigerant according to the second operating mode of Figure 5.

[Fig.7] shows a schematic view of the thermal management circuit of Figure 2 according to a third mode of operation.

[Fig.8] represents a pressure \ enthalpy diagram of the refrigerant according to the third mode of operation of Figure 7.

Identical elements in the different figures have the same references.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the characteristics apply only to a single embodiment. Simple features of different embodiments can 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 similar but not identical. This indexing does not imply a priority of an element, parameter or criterion over another and one can easily interchange such names without departing from the scope of this description. This indexing also does not imply an order in time for example to assess such or such criteria.

In the present application, the term "placed upstream" means that one element is placed before another with respect to the direction of circulation of a fluid. Conversely, by "placed downstream" is meant that one element is placed after another with respect to the direction of circulation of the fluid.

Figures 1 and 2 show a thermal management circuit 1 of an electric or hybrid motor vehicle in which a coolant circulates. This thermal management circuit 1 notably comprises a main loop A, a first circulation branch B and a second circulation branch C.

The main loop A more particularly comprises in the direction of circulation of the coolant:

• a compressor 3 comprising at least two compression stages, • a first heat exchanger 5 intended to be traversed by an external air flow 100, • a first expansion device 7, and • a second heat exchanger 9 intended to be related to the batteries of the electric or hybrid motor vehicle.

The coolant outlet of said second heat exchanger 9 is connected to the first compression stage of the compressor 3.

By external air flow 100 more particularly means a flow of air outside the motor vehicle. The first heat exchanger 5 can thus in particular be a condenser disposed on the front face of the motor vehicle and traversed by the external air flow 100 generated by the movement of the motor vehicle and / or by a fan.

The first circulation branch B for its part connects a first junction point 31 disposed downstream of the first heat exchanger 5, between said first heat exchanger 5 and the first expansion device 7, to a compression stage of the different compressor 3 from its first floor. The first circulation branch B comprises in the direction of circulation of the coolant:

• a second expansion device 11, and • a third heat exchanger 15 allowing heat exchanges with an internal air flow 200.

By internal air flow 200 is meant more particularly an air flow intended for the passenger compartment of the motor vehicle. This internal air flow 200 can in particular circulate in a heating, ventilation and air conditioning device also called HVAC in English for "Heating, Ventilation and Air-Conditioning".

According to a first embodiment illustrated in FIG. 1, the third heat exchanger 15 is in direct thermal relation with the internal air flow 200. By this, it is meant that the third heat exchanger 15 is intended to be traversed by the internal air flow 200.

The third heat exchanger 15 can then be placed directly in the heating, ventilation and air conditioning device in the internal air flow 200.

According to a second embodiment illustrated in FIG. 2, the third heat exchanger 15 is in indirect thermal relation with the internal air flow 200. The third heat exchanger 15 can then be a two-fluid heat exchanger placed jointly on the first circulation branch B and on a circulation loop D of a heat transfer fluid. This circulation loop D comprises in particular a pump 21, said third heat exchanger 15 and a fifth heat exchanger 23 intended to be traversed by the internal air flow 200. In this second embodiment, this fifth heat exchanger 23 can be more particularly arranged in the heating, ventilation and air conditioning device.

The second circulation branch C for its part connects a second junction point 32 to a third junction point 33. The second junction point 32 is notably arranged downstream of the first junction point 31, between said first junction point 31 and the first expansion device 7. The third junction point 33 is itself located downstream of the second heat exchanger 9, between said second heat exchanger 9 and the first compression stage of the compressor 3.

The second circulation branch C comprises in the direction of circulation of the coolant:

• a third expansion device 17, and • a fourth heat exchanger 19 intended to be traversed by the internal air flow 200.

The fourth heat exchanger 19 is also arranged in the heating, ventilation and air conditioning device. Preferably, this fourth heat exchanger 19 is arranged, in the direction of circulation of the internal air flow 200, upstream of the third heat exchanger 15 in the first embodiment (as illustrated in FIG. 1) or upstream of the fifth heat exchanger 23 in the second embodiment (as illustrated in Figure 2).

The fourth heat exchanger 19 may further include a phase change material. This phase change material makes it possible in particular to increase the thermal inertia of the fourth heat exchanger 19 and to cool the internal air flow 200 for a certain time even when the coolant does not circulate in the fourth heat exchanger 19 .

The first 7, second 11 and third 17 expansion devices may in particular include a stop function in order to block the circulation of the coolant when they are completely closed. Such a stop function makes it possible to control the circulation of the refrigerant fluid and thus to decide whether said refrigerant fluid circulates in the second heat exchanger 9, in the first circulation branch B and / or in the second circulation branch C.

An alternative solution (not shown) is to have a first stop valve on the main loop A between the second 32 and the third 33 junction point, a second stop valve on the first circulation branch B and a third valve stop on the second traffic branch C.

The thermal management circuit 1 may also include an internal heat exchanger 13 allowing the heat exchanges between the refrigerant leaving the second expansion device 11 on the second circulation branch B and the refrigerant circulating between the first 31 and the second junction point 32 on the main loop A.

Figures 3 to 8 show the thermal management circuit 1 of Figure 2, according to different modes of operation. These operating modes are not limited to the second embodiment and can completely be achieved by the first embodiment of FIG. 1.

In Figures 3, 5 and 7, only the portions in which the refrigerant circulates are shown. The difference in lines marks the pressure of the refrigerant. A thick line corresponds to a high pressure, a thin line corresponds to an intermediate pressure and the dotted line corresponds to a low pressure.

First operating mode:

Figure 3 shows the operation of the thermal management circuit 1 according to a first mode of operation. In this first operating mode, the refrigerant circulates in:

• the compressor 3, • the first heat exchanger 5 at which it loses heat, • a first part of the refrigerant passes through the main loop A and passes through the first expansion device 7 at which the refrigerant passes through at low pressure, the refrigerant then passes through the second heat exchanger 9 at which it absorbs heat before reaching the first compression stage of the compressor 3, • a second part of the refrigerant passes through the first circulation branch B and passing through the second expansion device 11 at which the refrigerant passes to an intermediate pressure, higher than the low pressure, the refrigerant then passing through the third heat exchanger 15 at which it absorbs heat before joining the second compressor compression stage 3.

Figure 4 shows a diagram of the evolution of the pressure (expressed in Pa) and the enthalpy (expressed in kJ / kg) of the refrigerant during this first operating mode.

In this first operating mode, the refrigerant first passes through the compressor 3 at the outlet of which the refrigerant is at high pressure, as illustrated by curve 300 of the diagram in FIG. 4.

The refrigerant then passes through the first heat exchanger 5 at which the refrigerant loses heat, in particular to the benefit of the external air flow 100, as illustrated by curve 500 of the diagram in FIG. 4.

At the first junction point 31, a first part of the refrigerant passes through the main loop A and passes through the first expansion device 7 at which the refrigerant passes at a low pressure, as illustrated by curve 700 of the diagram of FIG. 4. The refrigerant then passes through the second heat exchanger 9 at the level of which it absorbs heat, as illustrated by the curve 900 of the diagram in FIG. 4, before joining the first compression stage of the compressor 3.

Still at the first junction point 31, a second part of the refrigerant passes through the first circulation branch B and passes through the second expansion device 11 at which the refrigerant passes at an intermediate pressure, higher than the low pressure, as illustrated by curve 110 in the diagram in FIG. 4. The refrigerant then passes through the third heat exchanger 15 at the level of which it absorbs heat, as shown by curve 150 in the diagram in FIG. 4, before joining the second compression stage of compressor 3.

The third heat exchanger 15 can directly absorb heat energy in the internal air flow 200 in the context of the first embodiment of the thermal management circuit 1. In the context of the second embodiment of the thermal management circuit 1, the third heat exchanger 15 absorbs heat energy from the heat transfer fluid circulating in the circulation loop D. The heat transfer fluid circulating in the circulation loop D thus loses heat energy at the level of the third heat exchanger 15 and absorbs internal air flow 200 at the fifth heat exchanger 23.

In the case where the thermal management circuit 1 includes an internal heat exchanger 13, the latter allows sub-cooling of the refrigerant passing through the main loop A. Indeed, part of the heat energy of the refrigerant passing between the first 31 and the second 32 junction point is transferred to the refrigerant circulating in the first circulation branch B at the outlet of the second expansion device 11, as illustrated by the curves 130a and 130b of the diagram in FIG. 4.

This internal heat exchanger 13 makes it possible here to improve the coefficient of performance of the thermal management circuit 1 in this first operating mode.

In this first operating mode, the refrigerant does not circulate in the second circulation branch C. For this, the third expansion device 17 can for example be closed and block the circulation of the refrigerant.

This first operating mode makes it possible to cool the batteries efficiently via the second heat exchanger 9, in particular during rapid charging requiring a high cooling capacity to keep the batteries as close as possible to their optimum operating temperature. In addition, this first operating mode makes it possible, together with the cooling of the rapidly charging batteries, to also have direct or indirect pre-cooling of the internal air flow 200 via the third heat exchanger 15.

The fact that the second heat exchanger 9 is traversed by the low pressure refrigerant allows it to be allocated a greater cooling capacity. However, a lower cooling capacity is allocated to the third heat exchanger 15 because it is traversed by a refrigerant at an intermediate pressure.

In the case where the fourth heat exchanger 19 comprises a phase change material, the latter can also participate in the cooling of the internal air flow 200.

Second operating mode:

FIG. 5 shows the operation of the thermal management circuit 1 according to a second mode of operation. In this second operating mode, the refrigerant circulates in:

• the compressor 3, • the first heat exchanger 5 at which it loses heat, • a first part of the coolant passes through the first circulation branch B and passes through the second expansion device 11 at which the coolant passes to an intermediate pressure, the refrigerant then crosses the third heat exchanger 15 at which it absorbs heat before joining the second compression stage of the compressor 3, • a second part of the refrigerant passes through the first device expansion 7 at which the refrigerant passes to a low pressure, below the intermediate pressure, the refrigerant then passes through the second heat exchanger 9 at which it absorbs heat before reaching the first compression stage of the compressor 3 , • a third part of the refrigerant passes through the second branch circulation C and passes through the third expansion device 17 at which the refrigerant passes to the low pressure, the refrigerant then passes through the fourth heat exchanger 19 at which it absorbs heat before reaching the first compression stage of compressor 3.

Figure 6 shows a diagram of the evolution of the pressure (expressed in Pa) and of Γ enthalpy (expressed in kJ / kg) of the refrigerant during this second operating mode.

In this second operating mode, the refrigerant first passes through the compressor 3 at the outlet of which the refrigerant is at high pressure, as illustrated by curve 300 of the diagram in FIG. 6.

The refrigerant then passes through the first heat exchanger 5 at which the refrigerant loses heat, in particular to the benefit of the external air flow 100, as illustrated by curve 500 of the diagram in FIG. 6.

At the first junction point 31, a first part of the refrigerant passes through the first circulation branch B and passes through the second expansion device 11 at which the refrigerant passes at an intermediate pressure, as illustrated by the curve 110 of the diagram of Figure 6. The refrigerant then passes through the third heat exchanger 15, as shown by curve 150 of the diagram of Figure 6, at which it absorbs heat before joining the second compression stage of the compressor 3 .

The third heat exchanger 15 can directly absorb heat energy in the internal air flow 200 in the context of the first embodiment of the thermal management circuit 1. In the context of the second embodiment of the thermal management circuit 1, the third heat exchanger 15 absorbs heat energy from the heat transfer fluid circulating in the circulation loop D. The heat transfer fluid circulating in the circulation loop D thus loses heat energy at the level of the third heat exchanger 15 and absorbs internal air flow 200 at the fifth heat exchanger 23.

Downstream of the second junction point, a second part of the refrigerant circulates in the main loop A and passes through the first expansion device 7 at which the refrigerant passes at a low pressure, lower than the intermediate pressure, as illustrated by the curve 700 of the diagram in FIG. 6. The refrigerant then passes through the second heat exchanger 9 at the level of which it absorbs heat, as illustrated by curve 900 of the diagram of FIG. 6, before joining the third junction point. 33.

Still downstream of the second junction point, a third part of the refrigerant passes through the second circulation branch C and passes through the third expansion device 17 at which the refrigerant passes at a low pressure, lower than the intermediate pressure, as illustrated by curve 170 in the diagram in FIG. 6. The refrigerant then passes through the fourth heat exchanger 19 at the level of which it absorbs heat, as illustrated by curve 190 in the diagram in FIG. 6, before joining the third junction point 33.

After the third junction point 33, the low-pressure refrigerant joins the first compression stage of the compressor 3.

In the case where the thermal management circuit 1 includes an internal heat exchanger 13, the latter allows sub-cooling of the refrigerant passing through the main loop A. Indeed, part of the heat energy of the refrigerant passing between the first 31 and the second 32 junction point is transferred to the refrigerant circulating in the first circulation branch B at the outlet of the second expansion device 11, as illustrated by the curves 130a and 130b of the diagram in FIG. 6.

This internal heat exchanger here improves the coefficient of performance of the thermal management circuit 1 in this second mode of operation.

In this second operating mode, the refrigerant circulates in both the first B and the second C circulation branch.

This second operating mode makes it possible to cool the batteries efficiently via the second heat exchanger 9, in particular during rapid charging requiring a high cooling capacity to keep the batteries as close as possible to their optimum operating temperature. In addition, this second operating mode makes it possible, together with the cooling of the batteries in rapid charging, to also have cooling of the internal air flow 200. This cooling of the internal air flow 200 is carried out both directly or indirectly via the third heat exchanger 15 and by the fourth heat exchanger 19.

The fact that the second heat exchanger 9 is traversed by the low pressure refrigerant allows it to be allocated a greater cooling capacity. However, a lower cooling capacity is allocated to the third heat exchanger 15 because it is traversed by a refrigerant at an intermediate pressure.

In the case where the fourth heat exchanger 19 comprises a material with phase change, the latter can be "recharged" in this second mode of operation, in particular for being used subsequently, for example in the first embodiment. By "recharging" is meant here that the phase change material passes for example from the liquid phase to the solid phase.

Third operating mode:

FIG. 7 shows the operation of the thermal management circuit 1 according to a third mode of operation. In this third operating mode, the refrigerant circulates in:

• the compressor 3, • the first heat exchanger 5 at which it loses heat, • a first part of the coolant passes through the first circulation branch B and passes through the second expansion device 11 at which the coolant goes to an intermediate pressure, higher than the low pressure, the refrigerant then crosses the third heat exchanger 15 at which it absorbs heat before joining the second compression stage of the compressor 3, • a second part of the refrigerant passes through the second circulation branch C and passes through the third expansion device 17 at which the refrigerant passes at a low pressure, the refrigerant then passes through the fourth heat exchanger 19 at which it absorbs heat before joining the first compression stage of compressor 3.

Figure 8 shows a diagram of the evolution of the pressure (expressed in Pa) and the enthalpy (expressed in kJ / kg) of the refrigerant during this third operating mode.

In this third operating mode, the refrigerant first passes through the compressor 3 at the outlet of which the refrigerant is at high pressure, as illustrated by curve 300 of the diagram in FIG. 8.

The refrigerant then passes through the first heat exchanger 5 at which the refrigerant loses heat, in particular to the benefit of the external air flow 100, as illustrated by curve 500 of the diagram in FIG. 8.

At the first junction point 31, a first part of the refrigerant passes through the first circulation branch B and passes through the second expansion device 11 at which the refrigerant passes at an intermediate pressure, as illustrated by the curve 110 of the diagram of FIG. 8. The refrigerant then passes through the third heat exchanger 15 at the level of which it absorbs heat before joining the second compression stage of the compressor 3.

The third heat exchanger 15 can directly absorb heat energy in the internal air flow 200 in the context of the first embodiment of the thermal management circuit 1. In the context of the second embodiment of the thermal management circuit 1, the third heat exchanger 15 absorbs heat energy from the heat transfer fluid circulating in the circulation loop D. The heat transfer fluid circulating in the circulation loop D thus loses heat energy at the level of the third heat exchanger 15 and absorbs internal air flow 200 at the fifth heat exchanger 23.

Downstream of the second junction point, a second part of the refrigerant passes through the second circulation branch C and passes through the third expansion device 17 at which the refrigerant passes at a low pressure, lower than the intermediate pressure, as illustrated by curve 170 of the diagram in FIG. 8. The refrigerant then crosses the fourth heat exchanger 19 at the level of which it absorbs heat, as illustrated by curve 190 of the diagram of FIG. 8, before reaching the third point Junction 33.

After the third junction point 33, the low-pressure refrigerant joins the first compression stage of the compressor 3.

In the case where the thermal management circuit 1 includes an internal heat exchanger 13, the latter allows sub-cooling of the refrigerant passing through the main loop A. Indeed, part of the heat energy of the refrigerant passing between the first 31 and the second 32 junction point is transferred to the refrigerant circulating in the first circulation branch B at the outlet of the second expansion device 11, as illustrated by the curves 130a and 130b of the diagram in FIG. 8.

This internal heat exchanger 13 makes it possible here to improve the coefficient of performance of the thermal management circuit 1 in this third operating mode.

In this third operating mode, the refrigerant does not circulate in the main branch A between the second 32 and the third 33 junction point. For this, the first expansion device 7 can for example be closed and block the circulation of the refrigerant.

This third operating mode makes it possible to concentrate the cooling capacity of the thermal management circuit 1 towards the cooling of the internal air flow.

200. This cooling of the internal air flow 200 is carried out both directly or indirectly via the third heat exchanger 15 and by the fourth heat exchanger 19. This allows for example rapid cooling of the passenger compartment of the motor vehicle.

In the case where the fourth heat exchanger 19 comprises a material with phase change, the latter can be "recharged" in this second mode of operation, in particular for being used subsequently, for example in the first embodiment. By "recharging" is meant here that the phase change material passes for example from the liquid phase to the solid phase.

Other operating modes are possible without departing from the scope of the invention. For example, it is possible to imagine an operating mode in which the entire cooling capacity is used for cooling the batteries. For this, downstream of the first heat exchanger 5, the refrigerant circulates only via the first expansion device 7 at which it goes to low pressure and the second heat exchanger 9 at which it absorbs heat from the batteries before to reach the first compression stage of compressor 3.

In this example of operating mode, the refrigerant does not circulate in the first B and second C circulation branches. For this, the second 11 and third 17 expansion devices can be closed and block the circulation of the refrigerant.

Thus, it is clear that because of its architecture and the different operating modes enabled by this same architecture, the thermal management circuit allows joint cooling between that of the batteries, especially in fast charging, and of the passenger compartment.

Claims (8)

claims 1. Thermal management circuit (1) of an electric or hybrid motor vehicle in which a coolant circulates, said thermal management circuit (1) comprising a main loop (A) comprising in the direction of circulation of the coolant: ° a compressor (3) comprising at least two compression stages, ° a first heat exchanger (5) intended to be traversed by an external air flow (100), ° a first expansion device (7), and ° a second heat exchanger (9) intended to be in relation to the batteries of the electric or hybrid motor vehicle, the coolant outlet of said second heat exchanger (9) being connected to the first compression stage of the compressor (3), said thermal management circuit (1) comprising a first circulation branch (B) connecting a first junction point (31) disposed downstream of the first heat exchanger (5), between said first heat exchanger (5) and the first device expansion valve (7), at a compression stage of the compressor (3) different from its first stage, said first circulation branch (B) comprising in the direction of circulation of the coolant: ° a second expansion device (11), and ° a third heat exchanger (15) allowing the heat exchanges with an internal air flow (200), said thermal management circuit (1) comprising a second circulation branch (C) connecting a second junction point (32) disposed downstream of the first junction point (31), between said first junction point (31) and the first expansion device (7), to a third junction point ( 33) disposed downstream of the second heat exchanger (9), between said second heat exchanger (9) and the first compression stage of the compressor (3), said second circulation branch (C) comprising in the direction of circulation of the refrigerant: ° a third expansion device (17), and ° a fourth heat exchanger (19) intended to be traversed by the internal air flow (200). 2. Thermal management circuit (1) according to claim 1, characterized in that the third heat exchanger (15) is a two-fluid heat exchanger disposed jointly on the first circulation branch (B) and on a circulation loop ( D) of a heat transfer fluid, said circulation loop (D) comprising a pump (21), said third heat exchanger (15) and a fifth heat exchanger (23) intended to be traversed by the internal air flow (200). 3. Thermal management circuit (1) according to claim 1, characterized in that the third heat exchanger (15) is intended to be traversed by the internal air flow (200). 4. Thermal management circuit (1) according to any one of the preceding claims, characterized in that the fourth heat exchanger (19) further comprises a phase change material. 5. Thermal management circuit (1) according to any one of the preceding claims, characterized in that it further comprises an internal heat exchanger (13) allowing the heat exchanges between the refrigerant leaving the second device. expansion (11) and the refrigerant circulating between the first (31) and the second junction point (32). 6. Thermal management circuit (1) according to any one of claims 1 to 5, characterized in that it is configured in a first operating mode in which the coolant circulates in: ° the compressor (3), ° the first heat exchanger (5) at which it loses heat, ° a first part of the refrigerant passes through the main loop (A) and passes through the first expansion device (7) at which the refrigerant passes to a low pressure, the refrigerant then passing through the second heat exchanger (9) at which it absorbs heat before reaching the first compression stage of the compressor (3), ° a second part of the refrigerant passes through the first circulation branch (B) and passes through the second expansion device (11) at which the refrigerant passes at an intermediate pressure, higher than the low pressure, the refrigerant then crosses the third exchanger heat (15) at which it absorbs heat before joining the second compression stage of the compressor (3). 7. Thermal management circuit (1) according to any one of claims 1 to 5, characterized in that it is configured in a second operating mode in which the coolant circulates in: ° the compressor (3), ° the first heat exchanger (5) at which it loses heat, ° a first part of the refrigerant passes through the first circulation branch (B) and passes through the second expansion device ( 11) at which the refrigerant passes to an intermediate pressure, the refrigerant then passes through the third heat exchanger (15) at which it absorbs heat before joining the second compression stage of the compressor (3), ° a second part of the refrigerant passes through the first expansion device (7) at which the refrigerant passes at a low pressure, below the intermediate pressure, the refrigerant then passes through the second heat exchanger (9) at which it absorbs heat before reaching the first compression stage of the compressor (3), ° a third part of the refrigerant passes through the two th circulation branch (C) and passes through the third expansion device (17) at which the refrigerant passes to low pressure, the refrigerant then passes through the fourth heat exchanger (19) at which it absorbs heat before joining the first compression stage of the compressor (3). 8. Thermal management circuit (1) according to any one of claims 1 to 5, characterized in that it is configured in a third operating mode in which the coolant circulates in: ° the compressor (3), 5 ° the first heat exchanger (5) at which it loses heat, ° a first part of the refrigerant passes through the second circulation branch (C) and passing through the third expansion device (17) at which the refrigerant passes to a low pressure, the refrigerant then crosses the fourth heat exchanger (19) at which it absorbs heat 10 before joining the first compression stage of the compressor (3), ° a second part of the fluid refrigerant passes through the first circulation branch (B) and passes through the second expansion device (11) at which the refrigerant passes at an intermediate pressure, higher than the low pressure, the refrigerant then crosses the third heat exchanger ( 15) at the level of which it absorbs heat before joining the second compression stage of the compressor (3).