Heat transfer fluid circuit for heat treatment system

Abstract

Heat Transfer Fluid Circuit for a Heat Treatment System The present invention relates to a heat transfer fluid circuit (2) for a heat treatment system (1), comprising: a first loop (4) including a first pumping device (5), a first heat exchanger (6), a second heat exchanger (7) and a third heat exchanger (8), a first branch (10) extending between a first divergence point (11) located on the first loop (4) and a first convergence point (12) located on the first loop (4), a second loop (13) including a second pumping device (14), a fourth heat exchanger (15) and a fifth heat exchanger (16), characterized in that the first loop (4) and the second loop (13) are fluidically connected to each other by a second branch (17) and a third branch (18). (Figure 1)

Description

Title of the invention: Heat transfer fluid circuit for a heat treatment system

[0001] The present invention relates to the field of heat treatment systems of a motor vehicle, and more particularly concerns a heat transfer fluid circuit integrated into such heat treatment systems.

[0002] Motor vehicles are commonly equipped with a refrigerant circuit and at least one heat transfer fluid circuit, both used to contribute to the thermal treatment of different areas or components of the vehicle. It is particularly known to use the refrigerant circuit and / or the heat transfer fluid circuit to thermally treat an airflow sent into the passenger compartment of a vehicle equipped with such a circuit. This thermal treatment is achieved, in particular, by circulating the refrigerant within a ventilation, heating, and / or air conditioning system installed in the vehicle.

[0003] In another application of this circuit, it is known to use the heat transfer fluid circuit to cool components of the vehicle's powertrain, such as, for example, an electrical storage device, the latter being used to supply energy to an electric motor capable of propelling the vehicle. The heat treatment system thus provides the energy needed to cool the electrical storage device or the electric motor during its use in driving phases.

[0004] Within this type of circuit, improvements in thermal performance are constantly being developed, particularly with the aim of thermally treating the components of the vehicle's electric powertrain while combining efficiency and energy savings. In other words, depending on the outside temperature and / or the temperature of the component of the electric powertrain, the thermal treatment must be effective without wasting energy unnecessarily. Another objective is to be able to integrate both active cooling, i.e., via the refrigerant circuit, and passive cooling, i.e., via ambient air, for a component of the vehicle's electric powertrain.

[0005] The present invention falls within this context and, as such, proposes a heat transfer fluid circuit for a vehicle heat treatment system, intended to be traversed by a heat transfer fluid, comprising: - a first loop comprising a first pumping device, a first heat exchanger configured to perform a heat exchange between the heat transfer fluid and a refrigerant circulating in a circuit of refrigerant fluid, a second heat exchanger and a third heat exchanger, both configured to perform heat exchange between the heat transfer fluid and an external airflow to a vehicle passenger compartment, - a first branch extending between a first divergence point located on the first loop between the first heat exchanger and the second heat exchanger, and a first convergence point located on the first loop between the second heat exchanger and the third heat exchanger - a second loop comprising a second pumping device, a fourth heat exchanger configured to perform heat exchange between the heat transfer fluid and the refrigerant circulating in the refrigerant circuit and a fifth heat exchanger configured to thermally treat an element of the vehicle's electric powertrain,

[0006] characterized in that the first loop and the second loop are fluidically connected to each other by a second branch and a third branch, the second branch extending between a second divergence point disposed on the first loop between the second heat exchanger and the first convergence point and a second convergence point disposed on the second loop downstream of the fifth heat exchanger and upstream of the fourth heat exchanger,the third branch extending between a third divergence point located on the second loop between the fifth heat exchanger and the second convergence point, and a third convergence point located on the first loop between the first divergence point and the second heat exchanger.

[0007] Thanks to the heat transfer fluid circuit according to the invention, the electric powertrain component of the vehicle can be actively heat-treated via the fourth and fifth heat exchangers, but also passively via the second and third branches, which provide a fluid connection between the fifth heat exchanger, responsible for heating the electric powertrain component of the vehicle, and the second heat exchanger. Furthermore, it is possible to maximize the efficiency of the heat treatment by implementing active and passive heat treatment simultaneously in order to adapt to any situation dependent, for example, on the outside temperature or the temperature of the electric powertrain component of the vehicle.

[0008] The first loop ensures, in particular, the dissipation of heat captured within the first heat exchanger. The first pumping device allows the heat transfer fluid to circulate within the first loop, and the heat transfer fluid is heated by the refrigerant within the first heat exchanger if the circuit The refrigerant fluid is also in operation. The refrigerant is then at high pressure and high temperature and transfers its heat to the heat transfer fluid. This heat exchange ensures the condensation of the refrigerant in order to regulate its thermodynamic cycle as it circulates within the refrigerant circuit.

[0009] As mentioned previously, the second and third heat exchangers ensure the dissipation of the heat absorbed by the heat transfer fluid in the first heat exchanger. This dissipation occurs thanks to the flow of outside air passing through the second and third heat exchangers, thus cooling the heat transfer fluid. The latter can then efficiently absorb heat from the refrigerant again by circulating once more through the first heat exchanger.In order to be positioned along the path of the outside airflow, the second and third heat exchangers can, for example, be placed on the front of the vehicle.

[0010] The first branch is arranged in parallel with the second heat exchanger and bypasses it, allowing the heat transfer fluid to circulate directly from the first heat exchanger to the third heat exchanger. This configuration is useful when the second heat exchanger is configured to perform passive heat treatment of the vehicle's electric powertrain component. The third heat exchanger is always used to dissipate the heat from the heat transfer fluid absorbed in the first heat exchanger.

[0011] Advantageously, when the second heat exchanger is available, the heat transfer fluid heated by the refrigerant circulates within the second heat exchanger and then the third heat exchanger in order to maximize heat dissipation and improve the thermal performance of the heat treatment system.

[0012] The heat transfer fluid can circulate within the second loop independently of the first loop thanks to the second pumping device. Like the first heat exchanger, the fourth heat exchanger also ensures heat exchange between the refrigerant and the heat transfer fluid, but unlike the first heat exchanger, the refrigerant is at low pressure and low temperature, thus cooling the heat transfer fluid instead of heating it. The cooled heat transfer fluid can then cool the electric powertrain component of the vehicle by circulating within the fifth heat exchanger. The heat transfer fluid can then continue circulating within the second loop to continuously cool the electric powertrain component.

[0013] If passive heat treatment is required, fluid access to the second heat exchanger can be implemented, and, at the outlet of the fifth heat exchanger, the heat transfer fluid circulates in the third branch, passes through the second heat exchanger, and returns to the second loop via the second branch. Depending on the desired configuration, active and / or passive cooling of the vehicle's electric powertrain component can thus be implemented to optimally adapt to different conditions.

[0014] According to one feature of the invention, the fifth heat exchanger is configured to thermally treat an element of the vehicle's electric powertrain, including a vehicle electrical storage device, a vehicle electric motor, or a vehicle control unit. The electrical storage device allows for energy storage and can release heat, for example, after rapid charging. The electric motor can release heat when the vehicle is traveling at high speed. The control unit manages the electric powertrain and can also release heat during its operation. Regardless of the specific element of the vehicle's electric powertrain, the heat it generates can lead to overheating, and this element must be cooled to prevent malfunction. The heat transfer fluid circuit is therefore adapted to one of these elements.

[0015] According to one feature of the invention, the heat transfer fluid circuit comprises a third loop including a third pumping device, a sixth heat exchanger configured to perform heat exchange between the heat transfer fluid and the refrigerant circulating in the refrigerant circuit, and a seventh heat exchanger configured to perform heat exchange between the heat transfer fluid and an interior airflow intended to be sent to the vehicle's passenger compartment. The third pumping device, like the pumping devices mentioned above, allows the heat transfer fluid to be circulated.

[0016] The sixth heat exchanger functions identically to the fourth heat exchanger, namely, it cools the heat transfer fluid. The cooled heat transfer fluid then provides air conditioning for the vehicle's passenger compartment by circulating within the seventh heat exchanger, cooling the incoming airflow. This incoming airflow is then distributed into the vehicle's passenger compartment to provide air conditioning. As such, the seventh heat exchanger is advantageously integrated into a vehicle's ventilation, heating, and / or air conditioning system.

[0017] According to one feature of the invention, the heat transfer fluid circuit comprises a fourth loop including a fourth pumping device, an eighth heat exchanger configured to thermally treat an element of the chain of The vehicle's electric drive system and a ninth heat exchanger are configured to facilitate heat exchange between the heat transfer fluid and the outside airflow. The fourth loop provides heat treatment for another component of the vehicle's electric drive system. The heat from this component is absorbed by the heat transfer fluid as it circulates through the eighth heat exchanger and is subsequently dissipated in the ninth heat exchanger. This ninth heat exchanger, like the second and third heat exchangers, ensures that the heat from the heat transfer fluid is dissipated via the outside airflow. The ninth heat exchanger can therefore also be positioned at the front of the vehicle, for example, downstream of the second and / or third heat exchangers in relation to the direction of outside airflow.

[0018] According to one feature of the invention, the fourth loop includes a tenth heat exchanger configured to perform heat exchange between the heat transfer fluid and the interior airflow. The tenth heat exchanger contributes to heating the vehicle's passenger compartment. The interior airflow absorbs heat from the heat transfer fluid and is thus sent, heated, into the vehicle's passenger compartment. Like the seventh heat exchanger, the tenth heat exchanger is advantageously arranged within the vehicle's ventilation, heating, and / or air conditioning system.

[0019] According to this configuration, i.e. with the tenth heat exchanger within the fourth loop, the heat transfer fluid captures the heat released by the element of the vehicle's electric powertrain by circulating within the eighth heat exchanger, then gives these same calories to the internal airflow.

[0020] According to another feature of the invention, the first loop includes a tenth heat exchanger disposed between the first heat exchanger and the second heat exchanger, the tenth heat exchanger being configured to operate a heat exchange between the heat transfer fluid and the internal airflow.

[0021] According to another feature of the invention, the first branch includes a tenth heat exchanger configured to operate a heat exchange between the heat transfer fluid and the internal airflow.

[0022] These are alternatives to positioning the tenth heat exchanger within the fourth loop. According to these two alternatives, the tenth heat exchanger is placed downstream of the first heat exchanger, either on the first loop or on the first branch. Thus, the heat transfer fluid can heat the interior airflow after having itself been heated by the refrigerant within the first heat exchanger. The first heat exchanger thus provides a heat source for the heating the vehicle's passenger compartment, while also participating in the thermodynamic cycle of the refrigerant fluid as previously mentioned.

[0023] According to one feature of the invention, the second and third heat exchangers are superimposed relative to each other along the direction of the outside airflow, the second heat exchanger being positioned upstream of the third heat exchanger with respect to said direction of the outside airflow. This configuration improves the compactness of the heat transfer fluid circuit, particularly the section located at the front of the vehicle, without compromising the thermal performance of the heat transfer fluid.

[0024] The outside airflow passes successively through the second heat exchanger and then the third heat exchanger. The outside airflow thus increases in temperature as it passes through the second heat exchanger, but at a sufficiently low temperature to subsequently heat the heat transfer fluid circulating in the third heat exchanger as it passes through the latter.

[0025] According to one feature of the invention, the first divergence point and / or the third divergence point includes a diverting element. Such a diverting element may, for example, be a three-way valve allowing control over which loop or branch the heat transfer fluid is directed from the first divergence point and / or the third divergence point.

[0026] The invention also covers a vehicle heat treatment system, comprising a heat transfer fluid circuit as described above and a coolant circuit. As previously mentioned, the coolant circuit and the heat transfer fluid circuit interact to heat at least one element of the vehicle's powertrain and optionally the vehicle's passenger compartment.

[0027] Depending on the direction of flow of the refrigerant, the latter is compressed and put under high pressure and high temperature in a gaseous state by a compression device, then passes through the first heat exchanger to be condensed and cooled by the heat transfer fluid circulating in the first loop of the heat transfer fluid circuit.

[0028] Following this, the refrigerant passes through an expansion device which reduces the refrigerant's pressure and temperature. The refrigerant is then evaporated within the fourth heat exchanger, while simultaneously cooling the heat transfer fluid that also circulates within it.

[0029] Depending on the configuration of the heat treatment system, the refrigerant circuit can also be divided into two paths, each of which includes an expansion valve. Downstream of these valves, one path includes the fourth heat exchanger, while the other path includes the sixth heat exchanger. Depending on the circulation mode of the treatment system In thermal mode, the refrigerant can flow in one of these paths or be divided into two fractions, each flowing in one of the paths. Downstream of the heat exchangers ensuring the evaporation of the refrigerant, the two paths rejoin and the evaporated refrigerant is compressed again by the compression device.

[0030] The refrigerant circuit may optionally include other elements, for example, a receiver arranged at the outlet of the first heat exchanger to retain a gaseous fraction of the refrigerant that has not condensed, thereby limiting any circulation of two-phase refrigerant. The refrigerant circuit may also include an internal heat exchanger that exchanges heat between the high-pressure and low-pressure refrigerants to regulate the thermodynamic equilibrium of the refrigerant while improving the performance of the thermodynamic cycle of said refrigerant.

[0031] The invention also covers a vehicle heat treatment system, comprising a heat transfer fluid circuit as described above and a refrigerant circuit including a direct heat exchanger configured to perform heat exchange between the refrigerant and an interior airflow intended to be sent to the vehicle's passenger compartment. Alternatively, the heat treatment system may include a refrigerant circuit providing direct air conditioning for the vehicle's passenger compartment, i.e., without passing through the heat transfer fluid. In place of the sixth and seventh heat exchangers providing air conditioning for the vehicle's passenger compartment, the direct heat exchanger allows direct heat exchange between the refrigerant and the interior airflow.Since the refrigerant has been previously expanded via the expansion valve, the interior airflow is cooled as it passes through the direct heat exchanger and can then be sent into the vehicle's passenger compartment. As with the seventh and tenth heat exchangers present in some previously described embodiments, the direct heat exchanger can be arranged within the vehicle's ventilation, heating, and / or air conditioning system.

[0032] The invention also covers a method for heat-treating a vehicle, implemented by a heat-treatment system as described above, during which: - The component of the vehicle's electric powertrain is cooled via the fourth heat exchanger,

[0033] and / or - The element of the vehicle's electric powertrain is cooled via the second heat exchanger.

[0034] Depending on the need, different operating modes of the heat treatment system are implemented. The number of these operating modes makes it possible to optimally meet different needs that depend, for example, on temperature.

[0035] As previously mentioned, the heat treatment can be carried out actively, passively, or both simultaneously. Passive heat treatment is achieved using ambient air, via the second heat exchanger, which dissipates the heat absorbed by the heat transfer fluid. Active heat treatment, on the other hand, is achieved using the refrigerant circuit, via the fourth heat exchanger and the refrigerant.

[0036] According to a feature of the process: - The electric drivetrain component of the vehicle is cooled only via the fourth heat exchanger when the outside temperature is higher than the temperature of the electric drivetrain component. - The electric powertrain element of the vehicle is cooled only via the second heat exchanger, or via the second heat exchanger and via the fourth heat exchanger when the outside temperature is lower than the temperature of the electric powertrain element.

[0037] Optimal cooling is indeed dependent on the temperature of the electric drivetrain component. The higher its temperature, the greater the cooling required. The outside temperature is also important because it determines the heat dissipation capacity of the heat transfer fluid via the outside airflow. Based on these parameters, a circulation method is chosen to select the one that optimally combines efficiency and energy savings.

[0038] Passive cooling is also dependent on the outside temperature. Thus, if the outside temperature is higher than the temperature of the vehicle's electric powertrain component, passive cooling in such a configuration is useless, or even counterproductive. Conversely, if passive cooling is sufficient on its own, it is advantageous to use it as a priority in order to avoid wasting energy by operating an effective but potentially unnecessary active cooling system.

[0039] The choice of cooling solely via the second heat exchanger or via both the second and fourth heat exchangers depends on the temperature difference between the ambient temperature and the temperature of the electric drive system component. This choice also depends on the power demand on the electric drive system component.

[0040] Other features and advantages of the invention will become apparent from the following description on the one hand, and from several illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0041] [Fig-1] is a representation of a first embodiment of a heat treatment system according to the invention,

[0042] [Fig.2] is a representation of a first mode of circulation applied to the first method of implementing the heat treatment system,

[0043] [Fig.3] is a representation of a second mode of circulation applied to first embodiment of the heat treatment system,

[0044] [Fig.4] is a representation of a third mode of circulation applied to the first method of implementing the heat treatment system,

[0045] [Fig.5] is a representation of a fourth mode of circulation applied to first embodiment of the heat treatment system,

[0046] [Fig.6] is a representation of a fifth mode of circulation applied to first embodiment of the heat treatment system,

[0047] [Fig.7] is a representation of a second embodiment of the system of thermal treatment,

[0048] [Fig.8] is a representation of a third embodiment of the system of thermal treatment,

[0049] [Fig.9] is a representation of a fourth embodiment of the system of thermal treatment,

[0050] [Fig. 10] is a representation of a fifth embodiment of the heat treatment system.

[0051] The terms "upstream" and "downstream" used in the following description refer to the direction of flow of the fluid in question, i.e. the refrigerant or the heat transfer fluid.

[0052] In Figures 1 and 7 to 10, a heat transfer fluid circuit 2 is shown with solid lines and a refrigerant fluid circuit 3 is shown with dashed lines. In Figures 2 to 6, for each circuit, the portions through which their respective fluid flows are shown with solid lines and the portions without fluid circulation are shown with dashed lines. The solid lines indicating fluid circulation are also of different thicknesses for the refrigerant fluid circuit 3 when it is in use. More specifically, the thickest solid lines correspond to portions where the refrigerant flows at high pressure and the thinnest solid lines correspond to portions where the refrigerant flows at low pressure.

[0053] Figure 1 represents a heat treatment system 1 that can be integrated into a motor vehicle and includes a first embodiment of a heat transfer fluid circuit 2 according to the invention. This heat treatment system 1 is suitable for providing heat treatment of the vehicle's passenger compartment, but also heat treatment of at least one element of a vehicle's powertrain.

[0054] To this end, the heat treatment system 1 comprises a heat transfer fluid circuit 2 through which a heat transfer fluid circulates, and a refrigerant fluid circuit 3 through which a refrigerant circulates. The heat treatment system 1 is configured to operate various interactions between the heat transfer fluid and the refrigerant in order to optimally heat the vehicle passenger compartment and the electric powertrain component of the vehicle. The heat transfer fluid can, for example, be glycol water, while the refrigerant can advantageously be an R290 type fluid, i.e., propane, which meets European environmental protection standards, unlike other types of refrigerants used for heat treatment.

[0055] The heat transfer fluid circuit 2 is divided into several loops and branches fluidly linked to each other or not in order to multiply the functionalities of the heat treatment system 1.

[0056] The heat transfer fluid circuit 2 includes a first loop 4. This first loop 4 is provided with a first pumping device 5, a first heat exchanger 6, a second heat exchanger 7 and a third heat exchanger 8.

[0057] The first pumping device 5 is used to circulate the heat transfer fluid. The first heat exchanger 6 is configured to perform a heat exchange between the heat transfer fluid circulating within it and the refrigerant circulating in the refrigerant circuit 3.

[0058] At this stage of the refrigerant circuit 3, the refrigerant is at high pressure and high temperature. Within the first heat exchanger 6, heat is therefore transferred from the refrigerant to the heat transfer fluid. This allows both the heating of the heat transfer fluid and the condensation of the refrigerant in order to implement a thermodynamic cycle of the refrigerant.

[0059] The second heat exchanger 7 and the third heat exchanger 8 are configured to perform heat exchange between the heat transfer fluid circulating within them and an outside airflow 9 passing through them. Outside airflow is understood to mean an airflow that is not intended to be sent into the vehicle's passenger compartment. To be positioned along the path of the outside airflow 9, the second heat exchanger 7 and the third heat exchanger 8 can, for example, be arranged on the front of the vehicle.

[0060] In [Fig. 1] and the following figures, the second heat exchanger 7 and the third heat exchanger 8 are spaced apart for reasons of clarity of the figures, but advantageously, the second heat exchanger 7 and the third heat exchanger 8 are superimposed on each other so that in a direction the outside airflow 9 passes through the second heat exchanger 7 and the third heat exchanger 8 in series.

[0061] After the heat transfer fluid has captured the calories from the refrigerant within the first heat exchanger 6, the heat exchanges taking place in the second heat exchanger 7 and in the third heat exchanger 8 via the outside air flow 9 can in particular allow the dissipation of these calories captured by the heat transfer fluid.

[0062] The heat transfer fluid circuit 2 further comprises a first branch 10 extending between a first divergence point 11 located on the first loop 4 between the first heat exchanger 6 and the second heat exchanger 7 and a first convergence point 12 located on the first loop 4 between the second heat exchanger 7 and the third heat exchanger 8. The first branch 10 makes it possible to directly link the first heat exchanger 6 to the third heat exchanger 8 by bypassing the second heat exchanger 7.

[0063] The heat transfer fluid circuit 2 also includes a second loop 13 through which the heat transfer fluid can also circulate. The second loop 13 includes a second pumping device 14, a fourth heat exchanger 15, and a fifth heat exchanger 16. Just like the first pumping device 5, the second pumping device 14 allows the heat transfer fluid to be circulated.

[0064] The fourth heat exchanger 15 is configured to operate a heat exchange between the heat transfer fluid circulating in the second loop 13 and the refrigerant circulating in the refrigerant circuit 3. Unlike the heat exchange taking place in the first heat exchanger 6, the heat exchange taking place within the fourth heat exchanger 15 is done with the refrigerant at low pressure and low temperature, thus allowing the heat transfer fluid to be cooled.

[0065] The second loop 13 is dedicated to the thermal regulation of a component of the vehicle's electric powertrain. For this purpose, the fifth heat exchanger 16 provides thermal treatment to said component of the vehicle's electric powertrain by the heat transfer fluid. By circulating in the fifth heat exchanger 16, the heat transfer fluid is thus able to, for example, cool the component of the vehicle's electric powertrain.

[0066] According to an example valid for all the figures, the element of the vehicle's electric powertrain that is heat-treated by the second loop 13 is an electrical storage device. Alternatively, said element of the powertrain The vehicle's electric traction system can be an electric motor or a vehicle control unit. This component is likely to generate heat during operation and must be cooled to prevent malfunction.

[0067] The heat transfer fluid circuit 2 is characterized in that the first loop 4 and the second loop 13 are fluidically linked to each other by a second branch 17 and by a third branch 18. The second branch 17 begins at a second divergence point 19 located on the first loop 4 between the second heat exchanger 7 and the first convergence point 12 and extends to a second convergence point 20 located on the second loop 13 downstream of the fifth heat exchanger 16 and upstream of the fourth heat exchanger 15. The heat transfer fluid can thus circulate from the first loop 4 to the second loop 13 via this second branch 17.

[0068] The third branch 18 begins at a third divergence point 21 located on the second loop 13 downstream of the fifth heat exchanger 16 and upstream of the second convergence point 20, and extends to a third convergence point 22 located on the first loop 4 between the first divergence point 11 and the second heat exchanger 7. It is thus understood that the second branch 17 and the third branch 18 enable, in particular, a fluid connection between the second heat exchanger 7 and the fifth heat exchanger 16. This allows the electric traction chain element to be passively heated via the second heat exchanger 7. The heat released by the electric traction chain element can then be dissipated by the outside airflow 9 circulating within the second heat exchanger 7.The electric powertrain element can also be heat-treated both passively via the second heat exchanger 7 and actively via the fourth heat exchanger 15. Such a configuration improves the heat treatment possibilities of the vehicle's electric powertrain element in order to optimize said heat treatment in terms of its efficiency and energy savings.

[0069] As illustrated in [Fig. 1], the heat transfer fluid circuit 2 also includes a third loop 23 provided with a third pumping device 24, a sixth heat exchanger 25 and a seventh heat exchanger 26. Just like the fourth heat exchanger 15, the sixth heat exchanger 25 is configured to perform heat exchange between the heat transfer fluid and the refrigerant circulating in the refrigerant circuit 3. The heat exchange taking place within the sixth heat exchanger 25 is with the refrigerant at low pressure and low temperature, thus cooling the heat transfer fluid circulating in the third loop 23.

[0070] The seventh heat exchanger 26 is configured to perform heat exchange between the heat transfer fluid and an interior airflow 27. Unlike the exterior airflow 9, the interior airflow 27 is intended to be sent to the vehicle's passenger compartment for heating and cooling purposes. As such, the seventh heat exchanger 26 can be arranged within a ventilation, heating, and / or air conditioning system that directs the interior airflow 27 through the seventh heat exchanger 26 before sending it to the vehicle's passenger compartment. Within the seventh heat exchanger 26, the heat transfer fluid absorbs heat from the interior airflow 27, which is then cooled and sent to the vehicle's passenger compartment to provide air conditioning.

[0071] Several points of divergence of the heat transfer fluid circuit 2, for example the first point of divergence 11 and the third point of divergence 21, may respectively include a first bypass member 28 and a second bypass member 29. Such bypass members 28, 29 may be in the form of a three-way valve allowing a heat transfer fluid circulation to be determined.

[0072] The first bypass member 28 thus allows the heat transfer fluid to be guided so that it continues its circulation in the first loop 4 or circulates within the first branch 10. The second bypass member 29 allows the heat transfer fluid to be guided so that it continues its circulation in the second loop 13 or circulates within the third branch 18.

[0073] The refrigerant circuit 3 comprises a main channel 30 provided with a compression device 31 and the first heat exchanger 6. As previously stated, the refrigerant circulating in the main channel 30 passes through the first heat exchanger 6 and is condensed by transferring its heat to the heat transfer fluid also circulating within the first heat exchanger 6.

[0074] Downstream of the first heat exchanger 6, the main channel 30 splits into a first channel 32 and a second channel 33. The first channel 32 includes a first expansion member 34 and the fourth heat exchanger 15 while the second channel 33 includes a second expansion member 35 and the sixth heat exchanger 25.

[0075] Each of the expansion valves 34, 35 ensures an expansion of the refrigerant, which then decreases in pressure and temperature. Subsequently, the refrigerant can pass through the fourth heat exchanger 15 or the sixth heat exchanger 25, depending on the path through which the refrigerant flows. This choice of path is obviously dependent on the objectives that the heat treatment system 1 must fulfill. These heat exchanges ensure the cooling of the heat transfer fluid. while evaporating the refrigerant. Subsequently, the first path 32 and the second path 33 rejoin to reform the main path 30 and the refrigerant is then compressed again by the compression device 31.

[0076] Optionally, the refrigerant circuit 3 may advantageously include a receiver 36 at the outlet of the first heat exchanger 6. In a manner not shown, the receiver 36 may also be directly integrated into the first heat exchanger 6. The refrigerant circuit may also include an internal heat exchanger 37 configured to perform heat exchange between the high-pressure refrigerant flowing in the main channel 30 downstream of the first heat exchanger 6 and the low-pressure refrigerant flowing in the main channel 30 upstream of the compression device 31. Such an internal heat exchanger 37 improves the thermodynamic performance of the refrigerant circuit 3.

[0077] Figure 2 represents a first circulation mode within the heat treatment system according to the invention. The objective of this first circulation mode is to cool the component of the vehicle's electric powertrain, namely the electrical storage device in this example and subsequent ones. This device can emit heat during its operation, for example, following rapid recharging of the vehicle. Figure 2 thus illustrates active cooling, that is, cooling carried out by means of the refrigerant circuit, of the electrical storage device. Such active cooling is implemented under conditions of ambient temperature higher than the temperature of the vehicle's electrical storage device.

[0078] According to this first mode of circulation, the heat transfer fluid is put into circulation in the first loop 4 and in the second loop 13 of the heat transfer fluid circuit 2. The refrigerant fluid is put into circulation in the main channel 30 and in the first channel 32 of the refrigerant fluid circuit 3.

[0079] The refrigerant fluid is compressed at high pressure and high temperature by the compression device 31 and circulates within the first heat exchanger 6 where it is condensed by heat exchange with the heat transfer fluid circulating in the first loop 4.

[0080] The condensed, high-pressure refrigerant continues its circulation in the main channel 30 and flows through the internal heat exchanger 37, then through the first channel 32. The refrigerant is subsequently expanded by the first expansion valve 34 and then circulates at low pressure and low temperature through the fourth heat exchanger 15 to cool the heat transfer fluid by evaporation. After further circulation through the heat exchanger 37 to improve performance thermals of the refrigerant circuit 3, the refrigerant is again compressed by the compression device 31.

[0081] The circulation of the refrigerant fluid is implemented for the purpose of cooling the heat transfer fluid in the second loop 13. As previously mentioned, the second loop 13 enables the active thermal treatment of the element of the vehicle's electric powertrain, here the electrical storage device.

[0082] To this end, the heat transfer fluid is circulated in the second loop 13 via the second pumping device 14, and is cooled by the refrigerant as it circulates through the fourth heat exchanger 15. The heat transfer fluid then circulates through the fifth heat exchanger 16 to cool the electrical storage device. At the outlet of the fifth heat exchanger 16, the second bypass valve 29 directs the heat transfer fluid back to the fourth heat exchanger 15 to be cooled again and thus continue the thermal treatment of the electrical storage device.

[0083] The heat transfer fluid also circulates in the first loop 4 in order to condense the refrigerant within the first heat exchanger 6 and participate in the thermodynamic cycle of the refrigerant. Thus, the heat transfer fluid increases in temperature as it circulates within the first heat exchanger 6 because it absorbs heat from the refrigerant.

[0084] Subsequently, the heat transfer fluid continues its circulation within the first loop 4 until it circulates within the second heat exchanger 7 and then the third heat exchanger 8 so that the heat absorbed by the heat transfer fluid is dissipated with the help of the outside air flow 9. The circulation of the heat transfer fluid in series in the second heat exchanger 7 and then in the third heat exchanger 8 maximizes the dissipation of the heat accumulated by the heat transfer fluid, thus improving the performance of the heat treatment system 1. The electrical storage device is thus actively thermally treated, more specifically cooled, by the heat treatment system 1.

[0085] Fig. 3 represents a second circulation mode of the thermal treatment system 1. This second circulation mode is substantially identical to the first circulation mode, the objective being to thermally treat the electrical storage device in an active manner.

[0086] The only difference between the two circulation methods is the circulation of the heat transfer fluid within the first loop 4. Indeed, at the outlet of the first heat exchanger 6, the heat transfer fluid, heated by the refrigerant, circulates to the first divergence point 11 where the first bypass 28 directs it to the first branch 10, thus bypassing the second heat exchanger 7. The heat from the heat transfer fluid is therefore only dissipated by the outside airflow 9 at within the third heat exchanger 8. This circulation method avoids excessive pressure drop during circulation within the heat exchangers. If heat dissipation solely through the third heat exchanger 8 is sufficient, then this second circulation method is implemented.

[0087] The other fluid circulations being identical to what has been described in [Fig.2], reference will be made to the description of this figure for the structural and functional characteristics common to the two modes of circulation.

[0088] Figure 4 illustrates a third circulation mode for the heat treatment system 1. This circulation mode still allows for the heat treatment of the vehicle's electric powertrain element, but this time passively, unlike the two previous operating modes. Passive heat treatment means that it is carried out using ambient air.

[0089] According to this third circulation method, the heat transfer fluid is circulated in the second loop 13 and flows within the fourth heat exchanger 15 without exchanging heat with the refrigerant. The heat transfer fluid then thermally treats the electrical storage device by circulating within the fifth heat exchanger 16 and capturing the heat released by the electrical storage device.

[0090] Subsequently, the calories captured by the heat transfer fluid are dissipated within the second heat exchanger 7, thanks to the fluid connection between the first loop 4 and the second loop 13 made possible by the heat transfer fluid circuit 2. At the outlet of the fifth heat exchanger 16, the second bypass member 29 directs the heat transfer fluid into the third branch 18 so that it circulates within the second heat exchanger 7 and the calories captured are dissipated by the outside air flow 9.

[0091] At the outlet of the second heat exchanger 7, the heat transfer fluid circulates within the second branch 17 to join the second loop 13 in order to again capture the calories emitted by the electrical storage device by circulating within the fifth heat exchanger 16.

[0092] This third circulation method is useful if passive cooling is sufficient to thermally treat the electrical storage device. It is thus understood that this passive cooling ensures the thermal treatment of the electrical storage device while limiting the energy expenditure required to perform said thermal treatment. As illustrated in [Fig. 4], the refrigerant circuit 3 is entirely inactive, as is the heat transfer fluid circulation within the first loop 4, with the exception of the portion between the second branch 17 and the third branch 18, which greatly limits the energy consumed for the heat treatment while achieving the objective of said heat treatment simply by dissipating calories via the outside airflow 9.

[0093] Passive cooling alone is implemented when the outside temperature is lower than the temperature of the vehicle's electrical storage device, but under specific conditions. Indeed, for the outside airflow 9 to be sufficient on its own to cool the electrical storage device, the temperature difference between the outside temperature and the temperature of the vehicle's electrical storage device must be sufficiently high to allow for significant cooling.

[0094] Furthermore, the implementation of the third driving mode also depends on the power demand of the electrical storage device. For example, for a power demand of 20 kW, the temperature difference between the outside temperature and the temperature of the vehicle's electrical storage device must be at least 10°C. For a power demand of 10 kW, the temperature difference between the outside temperature and the temperature of the vehicle's electrical storage device must be at least 5°C.

[0095] Figure 5 illustrates a fourth circulation mode of the heat treatment system 1 according to the invention. This fourth circulation mode illustrates both active and passive heat treatment of the electrical storage device in order to optimize said heat treatment. This fourth circulation mode combines the circulation of the heat transfer fluid in the second loop 13 and within the second heat exchanger 7 of the third circulation mode with the circulation of the refrigerant in the refrigerant circuit 3 and the circulation of the heat transfer fluid in the first loop 4 of the second circulation mode. Such a configuration is implemented when the outside temperature is lower than the temperature of the vehicle's electrical storage device and passive heat treatment alone is insufficient.

[0096] Thus, the heat transfer fluid circulating in the second loop 13 captures the heat released by the storage device as it circulates within the fifth heat exchanger 16. The heat captured by the heat transfer fluid is then initially dissipated by the outside airflow 9 as the heat transfer fluid circulates within the second heat exchanger 7 via the third branch 18 and then the second branch 17 at the outlet of said second heat exchanger 7. Subsequently, the heat transfer fluid returns to the second loop 13 and is further cooled within the fourth heat exchanger 15 through heat exchange with the refrigerant. The heat transfer fluid circuit 2 according to the invention thus allows for the simultaneous active and passive thermal treatment of an element of the vehicle's electric powertrain.

[0097] Since the refrigerant circuit 3 is used in this fourth circulation mode, the heat transfer fluid must also circulate through the first heat exchanger 6 in order to condense the refrigerant by absorbing its heat and dissipating it. As the second heat exchanger 7 is already used for the passive thermal treatment of the electrical storage device, the heat transfer fluid absorbing heat from the refrigerant in the first heat exchanger 6 then circulates through the first branch 10 in order to dissipate the heat exclusively in the third heat exchanger 8, as illustrated in [Fig. 3].Such a configuration thus allows the second heat exchanger 7 to be dedicated on the one hand to the passive cooling of the electrical storage device, and on the other hand the third heat exchanger 8 to the dissipation of the calories captured by the heat transfer fluid in order to condense the refrigerant fluid via the first heat exchanger 6. .

[0098] Figure 6 illustrates a fifth circulation mode of the heat treatment system 1 according to the invention. This fifth circulation mode is similar to the first circulation mode, except that it also implements the third loop 23, in addition to the active heat treatment of the electrical storage device as described in Figure 2, in order to simultaneously provide air conditioning for the vehicle's passenger compartment.

[0099] Thus, the heat transfer fluid is also put into circulation in the third loop 23 by means of the third pumping device 24. In parallel, the refrigerant no longer circulates exclusively within the main channel 30 and the first channel 32, but also within the second channel 33, where the refrigerant, just as in the first channel 32, is expanded to cool the heat transfer fluid.

[0100] In this case, the refrigerant circulating in the second channel is expanded by the second expansion member 35, then evaporated within the sixth heat exchanger 25, cooling in parallel the heat transfer fluid circulating in the third loop 23. Thus the refrigerant, according to this fifth mode of circulation, is divided into two fractions, each circulating respectively within the first channel 32 and the second channel 33 to cool respectively the heat transfer fluid circulating in the second loop 13 and in the third loop 23.

[0101] The cooled heat transfer fluid in the sixth heat exchanger 25 continues its circulation in the third loop 23 until it circulates in the seventh heat exchanger 26. The interior airflow 27 passing through the seventh heat exchanger 26, the heat from the interior airflow 27 is transferred to the heat transfer fluid, thus cooling the interior airflow 27. The latter is then sent into the passenger compartment of the vehicle to air condition it.

[0102] According to the illustration in [Fig. 6], this fifth circulation mode is equivalent to the first circulation mode with the addition of vehicle cabin air conditioning. However, the addition of the vehicle cabin air conditioning function is applicable to all the circulation modes described above that have the refrigerant circuit 3 active, as is the case for the second and fourth circulation modes.

[0103] Figures 7 to 10 illustrate alternative embodiments of the heat transfer fluid circuit 2 and / or the heat treatment system 1 according to the invention.

[0104] The heat transfer fluid circuit 2 illustrated in Figures 7 to 9 is respectively a second embodiment, a third embodiment and a fourth embodiment of the heat transfer fluid circuit 2. Each of these embodiments includes a fourth loop 38 provided with a fourth pumping device 39, an eighth heat exchanger 40 and a ninth heat exchanger 4L. The fourth loop 38 is totally isolated from the other loops of the heat transfer fluid circuit 2.

[0105] The fourth pumping device 39 ensures the circulation of the heat transfer fluid in the fourth loop 38. The eighth heat exchanger 40 allows for the heat treatment of a component of the vehicle's electric powertrain other than the component of the vehicle's electric powertrain that is heat-treated by the fourth heat exchanger 15. In the example given, the component of the vehicle's electric powertrain that is heat-treated by the fourth heat exchanger 15 is the vehicle's electrical storage device. The component of the vehicle's electric powertrain that is heat-treated by the eighth heat exchanger 40 could therefore, for example, be the vehicle's electric motor. The latter may generate heat that requires cooling, for example, when the vehicle is traveling at high speed.

[0106] The ninth heat exchanger 41, just like the second heat exchanger 7 and the third heat exchanger 8, ensures the dissipation of heat from the heat transfer fluid using the outside air flow 9. The electric motor can thus be passively thermally treated.

[0107] The second embodiment, the third embodiment and the fourth embodiment are distinguished from one another by the position of a tenth heat exchanger 42. The latter is configured to operate a heat exchange between the heat transfer fluid and the interior airflow 27. The tenth heat exchanger 42 thus contributes to heating the passenger compartment of the vehicle.

[0108] In the second embodiment illustrated in [Fig. 7], the tenth heat exchanger 42 is positioned within the fourth loop 38, downstream of the eighth heat exchanger 40 with respect to the direction of flow of the heat transfer fluid. The heat transfer fluid circulating in the fourth loop 38 captures the calories emitted by the electric motor and subsequently transfers them to the interior airflow 27 which is then sent into the passenger compartment of the vehicle.

[0109] In the third and fourth embodiments illustrated in [Fig. 8] and [Fig. 9] respectively, the tenth heat exchanger 42 is positioned downstream of the first heat exchanger 6 with respect to the direction of flow of the heat transfer fluid. In [Fig. 8], the tenth heat exchanger 42 is positioned on the first loop 4, between the first divergence point 11 and the second heat exchanger 7. In [Fig. 9], the tenth heat exchanger 42 is positioned on the first branch 10. As described previously, when circulating within the first heat exchanger 6, the heat transfer fluid absorbs heat from the refrigerant to condense the latter. The heat transfer fluid is therefore at a high temperature at the outlet of the first heat exchanger 6 and thus provides a heat source to the interior airflow 27 as it circulates within the tenth heat exchanger 42, ensuring the heating of the vehicle's passenger compartment.

[0110] As the remaining structural and functional elements are identical to the first embodiment, reference should be made to the description in Figures 1 to 6 for details concerning the elements common to all embodiments. All the circulation modes described above are also operational when applied to the embodiments illustrated in Figures 7 to 9.

[0111] Figure 10 illustrates a fifth embodiment of the heat treatment system 1 according to the invention. This fifth embodiment differs from the preceding embodiments in that it does not include a third or fourth loop. The vehicle's passenger compartment is thus not cooled via the seventh heat exchanger but by a direct heat exchanger 43 located on the second line 33 of the refrigerant circuit 3, downstream of the second expansion valve 35. In other words, the refrigerant directly cools the interior airflow 27 without the intermediary of the heat transfer fluid. The heat transfer fluid circuit 2 is nevertheless still operational as described above for treating the component of the vehicle's electric powertrain. Thus, the circulation modes described in Figures 2 to 5 are also applicable to the fifth embodiment.

[0112] Of course, the invention is not limited to the examples just described and many modifications can be made to these examples without departing from the scope of the invention.

[0113] The invention, as described above, achieves its intended purpose and makes it possible to propose a heat transfer fluid circuit suitable for implementing active and / or passive heat treatment of an element of the electric traction chain of a vehicle. Variants not described here could be implemented without departing from the context of the invention, provided that, in accordance with the invention, they include a heat transfer fluid circuit conforming to the invention.

Claims

1. Demands Heat transfer fluid circuit (2) for a heat treatment system (1) of a vehicle and intended to be traversed by a heat transfer fluid, comprising: - a first loop (4) comprising a first pumping device (5), a first heat exchanger (6) configured to perform a heat exchange between the heat transfer fluid and a refrigerant circulating in a refrigerant circuit (3), a second heat exchanger (7) and a third heat exchanger (8) both configured to perform a heat exchange between the heat transfer fluid and an outside airflow (9) to a vehicle passenger compartment, - a first branch (10) extending between a first divergence point (11) located on the first loop (4) between the first heat exchanger (6) and the second heat exchanger (7) and a first convergence point (12) located on the first loop (4) between the second heat exchanger (7) and the third heat exchanger (8), - a second loop (13) comprising a second pumping device (14), a fourth heat exchanger (15) configured to perform heat exchange between the heat transfer fluid and the refrigerant circulating in the refrigerant circuit (3) and a fifth heat exchanger (16) configured to thermally treat an element of the vehicle's electric powertrain, characterized in that the first loop (4) and the second loop (13) are fluidly connected to each other by a second branch (17) and a third branch (18), the second branch (17) extending between a second divergence point (19) located on the first loop (4) between the second heat exchanger (7) and the first convergence point (12) and a second convergence point (20) located on the second loop (13) downstream of the fifth heat exchanger (16) and upstream of the fourth heat exchanger (15), the third branch (18) extending between a third divergence point (21) disposed on the second loop (13) between the fifth heat exchanger (16) and the second convergence point (20) and a third convergence point (22) disposed on the first loop (4) between the first divergence point (11) and the second heat exchanger (7).

2. Heat transfer fluid circuit (2) according to claim 1, wherein the fifth heat exchanger (16) is configured to heat-treat an element of the vehicle's electric powertrain from among a vehicle electrical storage device, a vehicle electric motor or a vehicle control unit.

3. Heat transfer fluid circuit (2) according to claim 1 or 2, comprising a third loop (23) having a third pumping device (24), a sixth heat exchanger (25) configured to operate a heat exchange between the heat transfer fluid and the refrigerant circulating in the refrigerant circuit (3) and a seventh heat exchanger (26) configured to operate a heat exchange between the heat transfer fluid and an interior airflow (27) intended to be sent to the vehicle's passenger compartment.

4. Heat transfer fluid circuit (2) according to claim 3, comprising a fourth loop (38) having a fourth pumping device (39), an eighth heat exchanger (40) configured to thermally treat an element of the vehicle's electric powertrain and a ninth heat exchanger (41) configured to operate a heat exchange between the heat transfer fluid and the outside airflow (9).

5. Heat transfer fluid circuit (2) according to the preceding claim, wherein the fourth loop (38) includes a tenth heat exchanger (42) configured to operate a heat exchange between the heat transfer fluid and the internal airflow (27).

6. Heat transfer fluid circuit (2) according to claim 4, wherein the first loop (4) comprises a tenth heat exchanger (42) disposed between the first heat exchanger (6) and the second heat exchanger (7), the tenth heat exchanger (42) being configured to operate a heat exchange between the heat transfer fluid and the internal airflow (27).

7. Heat transfer fluid circuit (2) according to claim 4, wherein the first branch (10) comprises a tenth heat exchanger (42) configured to operate a heat exchange between the heat transfer fluid and the internal airflow (27).

8. Heat transfer fluid circuit (2) according to any one of the preceding claims, wherein the second heat exchanger (7) and the third heat exchanger (8) are superimposed with respect to each other in a direction of circulation of the outside airflow (9), the second heat exchanger (7) being arranged upstream of the third heat exchanger (8) with respect to said direction of circulation of the outside airflow (9).

9. Heat transfer fluid circuit (2) according to any one of the preceding claims, wherein the first divergence point (11) and / or the third divergence point (21) comprises a deflection member (28, 29).

10. Heat treatment system (1) of a vehicle, comprising a heat transfer fluid circuit (2) according to any one of the preceding claims and a coolant fluid circuit (3).

11. Heat treatment system (1) of a vehicle, comprising a heat transfer fluid circuit (2) according to claim 1 or 2 and a refrigerant fluid circuit (3) comprising a direct heat exchanger (43) configured to operate a heat exchange between the refrigerant fluid and an interior airflow (27) intended to be sent to the passenger compartment of the vehicle.

12. A method for heat-treating a vehicle, implemented by a heat-treating system (1) according to claim 10 or 11, wherein: - the element of the vehicle's electric powertrain is cooled via the fourth heat exchanger (15), and / or - the element of the vehicle's electric powertrain is cooled via the second heat exchanger (7).

13. A heat treatment method according to the preceding claim, wherein the element of the vehicle's electric powertrain is cooled solely via the fourth heat exchanger (15) when the outside temperature is higher than the temperature of the element of the electric traction chain, The electric drive element of the vehicle is cooled only via the second heat exchanger (7), or via the second heat exchanger (7) and via the fourth heat exchanger (15) when the outside temperature is lower than the temperature of the electric drive element.

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