THERMAL MANAGEMENT SYSTEM FOR HYBRID OR ELECTRIC VEHICLES

Abstract

Thermal management system of a hybrid or electric vehicle, the thermal management system comprising a reversible air conditioning circuit (10) in which a refrigerant circulates and comprising a two-fluid heat exchanger (14) jointly arranged on a circuit (12) of the first heat transfer fluid, the circuit (12) of the first heat transfer fluid being configured such that, in a first mode of heating the internal airflow (Fi): - in a first loop (L1) of the first heat transfer fluid, the first heat transfer fluid passing through the heating device (54), for example, all of the fluid passing through the heating device (54), passes through the two-fluid heat exchanger (14) and in the first pump (52), the heating device (54) and the two-fluid heat exchanger (14) being active, and in that,Simultaneously or independently of the circulation of the first heat transfer fluid in the first loop (L1) of the first heat transfer fluid, the circuit is configured so that, in a second loop (L2) of the first heat transfer fluid, the first heat transfer fluid passing through the "batteries" heat exchanger (68) passes through the "electrical machines" heat exchanger (66). Figure 2,

Description

Title of the invention: THERMAL MANAGEMENT SYSTEM FOR HYBRID OR ELECTRIC VEHICLES Technical field of the invention

[0001] The invention relates to the field of motor vehicles and more particularly to a thermal management circuit for hybrid or electric motor vehicles. Technical background

[0002] In electric and hybrid vehicles, passenger compartment temperature control is generally managed by a reversible air conditioning system. Reversible means that this system can operate in cooling mode to cool the air destined for the passenger compartment and in heat pump mode to heat the air destined for the passenger compartment. This reversible air conditioning system may also include a bypass to manage the temperature of the electric or hybrid vehicle's batteries. It is thus possible to cool or even heat the batteries using the reversible air conditioning loop. In heat pump mode, heat is extracted from the outside air and transferred to an internal airflow that is blown into the passenger compartment to warm it.

[0003] However, when the outside temperature is very low, it is not possible to use the air conditioning circuit in such a heat pump mode.

[0004] It is therefore known to arrange an electric heating device in the internal airflow that directly heats the airflow. However, this requires the arrangement of an additional component in the airflow, which is expensive and adds bulk to the vehicle.

[0005] One of the aims of the present invention is therefore to remedy, at least partially, the drawbacks of the prior art and to provide an improved thermal management circuit. Summary of the invention

[0006] One aspect of the invention relates to a thermal management system for a hybrid or electric vehicle, the thermal management system comprising a reversible air conditioning circuit in which a refrigerant circulates and comprising a two-fluid heat exchanger arranged jointly on a circuit of a first heat transfer fluid, the air conditioning circuit comprising successively, in a main loop, a compressor, a first heat exchanger arranged to exchange heat with a heat transfer fluid, directly or indirectly, the heat transfer fluid being, for example, an internal airflow blown into the vehicle's passenger compartment, a refrigerant expansion device and a second heat exchanger arranged to exchanging heat with a heat transfer fluid, directly or indirectly, the heat transfer fluid being, for example, an internal airflow blown into the vehicle's passenger compartment,

[0007] the first heat transfer fluid circuit comprising:

[0008] - a first branch comprising a first pump, a heating device of the first heat transfer fluid and the two-fluid heat exchanger,

[0009] - a second branch, one upstream end of which is directly connected to the first branch downstream of the two-fluid heat exchanger, one downstream end of which is directly connected to one upstream end of the first branch,

[0010] in which the circuit of the first heat transfer fluid comprises:

[0011] - a third branch which includes a second pump and a third heat exchanger, for example an "electrical machines" heat exchanger which allows the exchange of heat between power electronics and / or an electric motor of the vehicle, on the one hand, and the first heat transfer fluid, on the other hand,

[0012] -a fourth branch which includes a fourth heat exchanger, for example a "batteries" heat exchanger which is configured to allow heat exchange between vehicle batteries and the first heat transfer fluid, the fourth branch having an upstream end which is connected to a downstream end of the first branch and a downstream end which is connected to the second branch, an upstream end of the fourth branch being connected to a downstream end of the third branch, and a downstream end of the fourth branch being connected to an upstream end of the third branch.

[0013] - the circuit of the first heat transfer fluid being configured such that, in a first method of heating the internal airflow:

[0014] - in a first loop of the first heat transfer fluid, the first fluid ca the heat transfer fluid passing through the heating device, for example the entire fluid passing through the heating device, passes through the two-fluid heat exchanger and into the first pump, the heating device and the two-fluid heat exchanger being active, in particular so as to heat the refrigerant passing through the two-fluid heat exchanger,

[0015] and, simultaneously or independently of the circulation of the first heat transfer fluid in the first loop of the first heat transfer fluid, the circuit is configured so that, in a second loop of the first heat transfer fluid, the first heat transfer fluid passing through the "batteries" heat exchanger, for example the entire first heat transfer fluid passing through the "batteries" heat exchanger passes through the "electrical machines" heat exchanger and into the second pump, in particular so as to heat the first heat transfer fluid passing through the "batteries" heat exchanger with the heat recovered by the "electrical machines" heat exchanger.

[0016] This system makes it possible to perform at least two functions with a circuit of a first simple heat transfer fluid, namely the function of heating the batteries by the electric motor and jointly the function of recovering heat from the electric heating device to the passenger compartment of the vehicle.

[0017] According to certain aspects of the invention, the above system comprises one or more of the following features taken individually or in all technically possible combinations:

[0018] - in the first branch, the two-fluid heat exchanger is arranged downstream of the heating device for the first heat transfer fluid, preferably directly downstream;

[0019] - in addition to the first pump, the heating device for the first heat transfer fluid and the two-fluid heat exchanger, the first branch does not include any other device likely to significantly modify the amount of heat accumulated by the first heat transfer fluid;

[0020] - the second branch does not include any device capable of modifying the sense likely the amount of heat accumulated by the first heat transfer fluid;

[0021] - the circuit of the first heat transfer fluid is configured to be able to circulate the the entirety of the refrigerant fluid passing through the heating device and the two-fluid heat exchanger through the "batteries" heat exchanger in a third loop of the first heat transfer fluid, in particular so as to heat the first heat transfer fluid passing through the "batteries" heat exchanger when the heating device is active or alternatively so as to cool the first heat transfer fluid passing through the "batteries" heat exchanger when the two-fluid heat exchanger is active;

[0022] - the circuit of the first heat transfer fluid includes a first three-way valve connecting the first branch downstream of the two-fluid heat exchanger, the fourth branch upstream of the "batteries" heat exchanger and the upstream end of the second branch;

[0023] - the circuit of the first heat transfer fluid includes a fifth branch equipped of a radiator arranged in an external airflow, a downstream end of the fifth branch being connected to an upstream end of the third branch and an upstream end of the fifth branch being connected to a downstream end of the third branch, the circuit being configured to be able to circulate, in a fourth loop of the first heat transfer fluid, the entirety of the first heat transfer fluid passing through the "electrical machines" heat exchanger through the external radiator and the second pump, in particular so as to allow passive cooling of the first heat transfer fluid passing through the "electrical machines" heat exchanger by cooling in the external radiator;

[0024] - the circuit of the first heat transfer fluid includes a second three-way valve connecting the third branch downstream of the "electrical machines" heat exchanger, the fourth branch upstream of the "batteries" heat exchanger and the fifth branch upstream of the external radiator;

[0025] - the circuit includes a sixth branch connecting the fifth branch upstream of the external radiator and the fourth branch downstream of the heat exchanger "batteries", and a seventh branch connecting the first branch upstream of the heating device and the fifth branch downstream of the external radiator;

[0026] - the circuit of the first heat transfer fluid is configured to allow circulation of the first heat transfer fluid in a fifth mouth of the first heat transfer fluid in which the entire fluid passing through the "batteries" heat exchanger passes through the external radiator, in particular by passing through the seventh branch and the sixth branch, in particular so as to allow passive cooling of the first heat transfer fluid passing through the "batteries" heat exchanger by cooling in the external radiator;

[0027] - the circuit of the first heat transfer fluid is configured to allow in parallel to the fifth loop of the first heat transfer fluid, the circulation of the first heat transfer fluid in the fourth loop of the first heat transfer fluid in which all of the fluid passing through the "electrical machines" heat exchanger passes through the external radiator, the fluid circulating in the fifth branch being divided between the seventh branch towards the battery heat exchanger and the third branch towards the "electrical machines" heat exchanger, in particular so as to allow simultaneously the passive cooling of the first heat transfer fluid passing through the "batteries" heat exchanger and of the first heat transfer fluid passing through the "electrical machines" heat exchanger by cooling in the external radiator;

[0028] - the circuit of the first heat transfer fluid includes a third three-way valve connecting the fourth branch downstream of the "batteries" heat exchanger, the second branch and the sixth branch, in particular so as to connect or not the batteries heat exchanger to the external radiator;

[0029] - the circuit of the first heat transfer fluid is configured to allow circulation of the heat transfer fluid in the third loop of the first heat transfer fluid in which all of the fluid passing through the heat exchanger "electrical machines" passes through the external radiator and in the fourth loop of the first heat transfer fluid in which all of the refrigerant passing through the heat exchanger "batteries", passes through the heating device and the two-fluid heat exchanger;

[0030] - the circuit of the first heat transfer fluid includes a fourth valve connecting the fourth branch downstream of the heat exchanger "batteries", the third valve and the third branch upstream of the heat exchanger "electrical machines", in particular so as to be able to prevent with the third and fourth valves the circulation of the first heat transfer fluid from the third loop of the first heat transfer fluid to the fourth loop of the first heat transfer fluid through the sixth branch and through the third branch;

[0031] -the first heat transfer fluid circuit is configured to allow the fluid circulating through the "batteries" heat exchanger to pass upstream on one side through the heating device, the bi-fluid heat exchanger and the first pump, thus forming the third loop of the first heat transfer fluid and on the other side through a sixth loop of the first heat transfer fluid by passing through the "electrical machines" heat exchanger and the second pump, so as to allow in particular a mode of heat recovery by the refrigerant fluid circuit, the calories being supplied by the "electrical machines" heat exchanger, the heating device and / or the "batteries" heat exchanger.

[0032] Another aspect of the invention relates to a method of operating a system realized as described above, in which, in a first mode of heating the internal airflow, the entire first heat transfer fluid passing through the heating device then passes through the two-fluid heat exchanger before returning to the first pump through the second branch, the heating device and the two-fluid heat exchanger being active. Brief description of the figures

[0033] Other features and advantages of aspects of the invention will become apparent during the reading of the detailed description which follows, for the understanding of which reference will be made to the attached drawings described succinctly below.

[0034] Fig. 1 is a schematic view that represents an example of an air conditioning circuit that equips the thermal management system implemented according to one aspect of the invention.

[0035] Figure [Fig. 2] is a schematic view representing a circuit of the first fluid ca loporteur which equips the thermal management system made according to one aspect of the invention and which is intended to operate in cooperation with the air conditioning circuit of the [Fig.1].

[0036] Fig. 3 is a view of the circuit of the first heat transfer fluid of Fig. 1. operating in an active heating mode of an internal airflow and passive heating of one or more batteries (i.e. batteries) of the vehicle.

[0037] Fig. 4 is a view of the circuit of the first heat transfer fluid of Fig. 1. operating in an active cooling (or active heating) mode for the batteries and passive cooling of an electric motor and / or power electronics of the vehicle.

[0038] Fig. 5 is a view of the circuit of the first heat transfer fluid of Fig. 1 operating in an internal heat recovery heating mode in the two-fluid heat exchanger 14, the heat being supplied by the electric heating device 14 and / or the battery heat exchanger 68 and / or the electric motor heat exchanger 66.

[0039] Fig. 6 is a schematic view which represents a circuit of the first heat transfer fluid which equips the thermal management system made according to another aspect of the invention, and which is intended to operate in cooperation with the air conditioning circuit of Fig. 1.

[0040] Fig. 7 is a view of the circuit of the first heat transfer fluid of Fig. 5 operating in a passive cooling mode for the batteries, electric motor and / or power electronics of the vehicle.

[0041] Fig. 8 is a view of the circuit of the first heat transfer fluid of Fig. 5 operating in a mode of cooling the batteries and passively cooling the electric motor and / or the power electronics of the vehicle.

[0042] Fig.9 is a view of the circuit of the first heat transfer fluid of Fig.5 operating in an active cooling mode for the batteries of the electric motor and / or the power electronics of the vehicle. Detailed description of the invention

[0043] In the following description, elements having an identical structure or analogous functions will be designated by the same reference.

[0044] In the following description, the term "a first element upstream of a second element" means that the first element is positioned before the second element with respect to the direction of flow, or path, of a fluid. Similarly, the term "a first element downstream of a second element" means that the first element is positioned after the second element with respect to the direction of flow, or path, of the fluid in question. The direction of flow is defined by the compressor arrows or, where applicable, by the pump arrows.

[0045] The term "branch" here refers to a section of circuit open at both ends comprising only elements arranged in series.

[0046] It should also be noted that the term "batteries" should not be understood as all the batteries of the vehicle but as several batteries.

[0047] The term “battery” should be understood as any energy storage unit capable of returning that energy in electrical form.

[0048] In the drawings, the pipes in which the heat transfer fluid is moving will be shown in bold lines and the pipes in which the heat transfer fluid is not in motion in fine lines.

[0049] As illustrated in the various figures, the invention relates to a thermal conditioning system. For example, it relates to a thermal management system for a motor vehicle. This concerns an electric or hybrid motor vehicle that includes an electric motor which provides torque to the vehicle's drive wheels. The electric motor is powered by at least some batteries, referred to as traction batteries. During vehicle operation, the electric motor and the battery are likely to generate heat.

[0050] As more particularly illustrated in [Fig. 1], said system comprises a first air conditioning circuit 10 in which a refrigerant fluid circulates (or "refrigerant fluid circuit"), as shown in [Fig. 1], and a second circuit 12 of the first heat transfer fluid in which a heat transfer fluid circulates, as shown in [Fig. 2].

[0051] The heat transfer fluid is, for example, a heat transfer liquid such as water containing an antifreeze, in particular glycol water, or any other suitable heat transfer fluid. The refrigerant is, for example, a hydrofluorocarbon, such as R-134a, R1234yf, or R744.

[0052] The air conditioning circuit 10 includes a two-fluid heat exchanger 14 arranged jointly on the second circuit 12 for circulating a heat transfer fluid. The two-fluid heat exchanger 14 is configured to allow heat exchange between the refrigerant, circulating in the air conditioning circuit 10, and the first heat transfer fluid, circulating in the first heat transfer fluid circuit 12, without mixing between the heat transfer fluid and the refrigerant. This type of heat exchanger is commonly called a "chiller" by those skilled in the art, in the example of [Fig. 1],

[0053] The air conditioning circuit 10 is configured to allow, in a heat pump mode, the heating of an airflow, illustrated by an arrow marked Fi, by means of a compression and expansion of the refrigerant fluid.

[0054] The airflow Fi is, for example, an interior airflow Fi, intended to be sent into the vehicle's passenger compartment to enable its heating. The system thus makes it possible to heat the vehicle's passenger compartment using heat extracted from the first heat transfer fluid.

[0055] The interior airflow (Fi) circulates, for example, in a heating, ventilation and / or air conditioning (HVAC) device 16 of the passenger compartment.

[0056] By way of non-limiting example, the air conditioning circuit 10 shown in [Fig. 1] more particularly comprises a main refrigerant circulation loop A1 comprising, in the direction of refrigerant circulation, the compressor 18, the condenser 20 disposed in the internal airflow F1, a second device 24 Expansion, an evaporator-condenser 26 is located in an external airflow Fe. The evaporator-condenser 26 is thus generally located at the front of the motor vehicle. A flap (not shown) may also be installed in the heating, ventilation and / or air conditioning unit 16 to allow or prevent the internal airflow from passing through the condenser 20. The main refrigerant circulation loop Al may also include an accumulator 28 for phase separation of the refrigerant, located upstream of the compressor 18, between the evaporator-condenser 26 and said compressor 18. The condenser 20 transfers heat to the internal airflow Fi.

[0057] The condenser 20 is arranged here in the heating, ventilation and / or air conditioning device 16 to allow heat exchange between the refrigerant and the internal airflow Fi. The condenser 20 is, in particular, arranged directly in the internal airflow.

[0058] In an alternative not shown according to one aspect of the invention, the condenser 20 allows heat to be exchanged with the internal airflow via a heat transfer fluid circuit. In this case, the condenser 20 transfers heat to this heat transfer fluid, and then the heat transfer fluid transfers said heat to the internal airflow via a heat exchanger, called a "heater core", arranged directly in the internal airflow.

[0059] The refrigerant is in a high-pressure gaseous state as it exits the compressor 18. It then undergoes condensation as it passes through the condenser 20, releasing heat to the internal airflow Fi, and changes to a liquid state. It then undergoes expansion in the first expansion device 22 and passes into the first two-fluid heat exchanger 14 where it evaporates, absorbing heat from the heat transfer fluid.

[0060] By recovering heat from the second circuit 12 of the first heat transfer fluid, it is possible to heat the internal airflow Fi by means of the condenser 20 even when the outside temperature is too low for the first air conditioning circuit 10 to operate in external heat pump mode by exchanging heat with the outside air. This notably eliminates the need to equip the heating, ventilation and / or air conditioning unit 16 with an electric air heater.

[0061] The air conditioning circuit 10 is reversible here. This means that it is also capable of operating in an internal airflow cooling mode Fi.

[0062] The air conditioning circuit 10 also includes a first branch A2 for the circulation of refrigerant, connected in parallel with the evaporator-condenser 26 of the main loop AL. This first branch A2 connects more specifically:

[0063] - a first junction point 30 disposed downstream of the condenser 20 on the loop main A1, between said condenser 20 and the second expansion device 24, and

[0064] - a second junction point 32 disposed downstream of the evaporator-condenser 26 on the main loop Al, between said evaporator-condenser 26 and compressor 18, more precisely upstream of accumulator 28.

[0065] This first branch of the A2 branch includes in particular a third expansion device 33 and an evaporator 34 disposed in the internal airflow Fi.

[0066] The air conditioning circuit 10 further includes a second branch A3 connecting the outlet of the evaporator-condenser 26 and the inlet of the third expansion device 33. This third circulation line A3 connects, in particular:

[0067] - a third junction point 36 disposed downstream of the evaporator-condenser 26 on the main loop A1, between said evaporator-condenser 26 and compressor 18, more precisely upstream of accumulator 28, and

[0068] - a fourth junction point 38 arranged on the first branch of the branch A2 upstream of the third decompression device 33, between the first junction point 30 and the third decompression device 33.

[0069] The air conditioning circuit 10 also includes a third branch A4 connecting the inlet of the third expansion device 33 and the inlet of the compressor 18. This third branch of the A4 branch connects precisely:

[0070] - a fifth junction point 40 disposed on the first branch of the branch A2 upstream of the third expansion device 33, between the fourth junction point 38 of the third circulation line A3 and said third expansion device 33, and

[0071] - a sixth junction point 42 disposed upstream of the compressor 18, between the evaporator 34 and the second junction point 32 of the first branch of the bypass A2, more precisely upstream of the accumulator 28.

[0072] The third branch branch A4 includes in particular the first expansion device 22 and the bifluid heat exchanger 14. The first expansion device 22 is arranged upstream of the bifluid heat exchanger 14, between the fifth junction point 40 and said bifluid heat exchanger 14.

[0073] The air conditioning circuit 10 also includes a refrigerant redirection device to determine which branch it flows through. In the example illustrated in [Fig. 1], this refrigerant redirection device includes, in particular:

[0074] - a first shut-off valve 44 arranged on the first branch of the A2 branch between the first junction point 30 and the fourth junction point 38,

[0075] - a second shut-off valve 46 disposed on the first circulation loop Al of refrigerant fluid between the third junction point 36 and the second junction point 32,

[0076] - a non-return valve 48 disposed on the third circulation line A3, disposed so as to prevent the circulation of refrigerant fluid from the fourth point of junction 38 towards the third junction point 36,

[0077] - a non-return valve 50 disposed on the first branch of the branch A2, disposed so as to prevent the circulation of refrigerant fluid from the sixth junction point 42 to the evaporator 34.

[0078] The first 22, second 24 and third 33 expansion devices have a stop function to prevent the refrigerant fluid from passing through them when activated.

[0079] However, it is quite possible to imagine other means of defining through which branch the refrigerant flows, such as three-way valves strategically placed at junction points.

[0080] When the air conditioning circuit 10 operates in internal heat pump mode (also commonly referred to as "heat recovery" mode by those skilled in the art), the shut-off valves are controlled so that the refrigerant circulates in the third branch of the bypass A4 and not in the evaporator-condenser 26. The two-fluid heat exchanger 14 then functions as an evaporator for the refrigerant, while the refrigerant does not circulate in the evaporator-condenser 26, so that only the heat from the heat transfer fluid in the first heat transfer fluid circuit 12 is used to heat the internal airflow Fi. In this internal heat pump operating mode, the two-fluid heat exchanger 14 is active as an evaporator for the refrigerant.

[0081] The circuit 12 of the first heat transfer fluid is now described with reference to [Fig.2],

[0082] The circuit 12 of the first heat transfer fluid includes a first branch B1 of circulation of the first heat transfer fluid comprising, depending on the direction of circulation of the heat transfer fluid, a device 54 for heating the heat transfer fluid and said bi-fluid heat exchanger 14. The circuit 12 also includes a circulation pump 52, which is for example upstream of the device 54 for heating the heat transfer fluid.

[0083] The heat transfer fluid heating device 54 is here an electric heating device, for example which heats the heat transfer fluid for example by means of electric resistances or any other suitable electric heating means.

[0084] The circuit 12 of the first heat transfer fluid also includes a second branch B2, an upstream end of which is connected directly to the first branch B1 at a first connection point 56 downstream of the two-fluid heat exchanger 14. A downstream end of the second branch B2 is connected directly to the first branch B1 at a second connection point 58 arranged upstream of the electric heating device 54, more particularly upstream of the first pump 52 in this example.

[0085] Apart from the first pump 52, the heat transfer fluid heating device 54, and the two-fluid heat exchanger 14, the first branch B1 does not include any other device capable of significantly altering the amount of heat accumulated by the heat transfer fluid. In particular, the first branch B1 does not include any other heat exchanger. More specifically, the two-fluid heat exchanger 14 is arranged directly downstream of the heat transfer fluid heating device without any intervening device.

[0086] Similarly, the second branch B2 does not include any device capable of significantly altering the amount of heat accumulated by the heat transfer fluid. In particular, the second branch B2 does not include any heat exchanger. It should be noted that the second branch B2 includes, for example, according to an unshown variant, an expansion vessel-type device.

[0087] The circuit 12 of the first heat transfer fluid is configured such that, in a first mode of heating the internal airflow Fi, all of the heat transfer fluid passing through the heating device 54 then passes through the bifluid heat exchanger 14 before returning to the electric heating device 54 via the second branch B2, thus forming a first loop L1 of circulation of the first heat transfer fluid, which also includes the first 52. Note that the pump 52 can be located at another location in the loop L1, for example directly upstream or downstream of the bifluid heat exchanger 14.

[0088] In this first mode of heating the internal airflow Fi, the heating device 54 is active and the two-fluid heat exchanger 14 is active with a refrigerant evaporator function. This operating mode is illustrated in particular in [Fig. 3], in which the pipes through which the heat transfer fluid circulates are shown in bold, the heat transfer fluid remaining substantially still in the pipes not shown in bold. The direction of flow of the heat transfer fluid is indicated by the direction of the triangle in the pump 52.

[0089] The air conditioning circuit 10 operates simultaneously in internal heat pump mode. Thus, the heating device 54 supplies heat to the heat transfer fluid circulated by the first pump 52. Part of this heat is transferred to the refrigerant via the two-fluid heat exchanger 14, so as to then heat the internal airflow Fi via the condenser 20. All of the circulating heat transfer fluid then returns to the first pump 52 via the second branch B2 to be heated again by the heating device 54. Thus, the heat accumulated by the heat transfer fluid increases rapidly with each new cycle in a first loop formed by the first branch B1 and the second branch B2. This allows the temperature of the internal airflow Fi to rise rapidly via the circuit 10. air conditioning.

[0090] To allow for rapid heating, the first loop formed solely by the first branch B1 and the second branch B2 is advantageously very short. Advantageously, this loop comprises only the first pump 52, the heating device 54 and the two-fluid heat exchanger 14 and optionally an expansion vessel 60, as well as means for redirecting the heat transfer fluid solely within this first loop L1.

[0091] The circuit 12 of the first heat transfer fluid includes a third branch B3 which comprises a second pump 64 for circulating the first heat transfer fluid and a heat exchanger "electrical machines", which is configured to allow heat exchange between power electronics and / or an electric motor of the vehicle, on the one hand, and the heat transfer fluid, on the other. Alternatively, it is a heat exchanger dedicated to another function in the vehicle. Generally, it is a heat exchanger through which the heat transfer fluid circulates.

[0092] The term "power electronics" shall include electronic devices separate from the batteries and the electric motor.

[0093] In the embodiment shown in the figures, the heat exchanger "electric machines" exchanges heat with the electric motor.

[0094] The circuit 12 of the first heat transfer fluid also includes a fourth branch B4 which includes a battery heat exchanger 68, configured to allow heat exchange between the vehicle's batteries and the heat transfer fluid. The fourth branch B4 has an upstream end connected to a downstream end of the first branch B1 and a downstream end connected to the second branch (B2), an upstream end of the fourth branch (B4) also being connected to a downstream end of the third branch (B3), and a downstream end of the fourth branch (B4) being connected to an upstream end of the third branch (B3).

[0095] As illustrated in [Fig.3], the circuit 12 of the first heat transfer fluid is configured so that, in a second loop L2 of the first heat transfer fluid, the heat transfer fluid passing through the heat exchanger "batteries" 68, for example, all of the heat transfer fluid passing through the heat exchanger "batteries" 68 passes through the heat exchanger "electrical machines" 66 and into the second pump 64.

[0096] The second loop L2 illustrated in [Fig.3] allows the heat transfer fluid passing through the "batteries" heat exchanger 68 to be heated by the heat recovered by the "electrical machines" heat exchanger 66.

[0097] Apart from the second pump 64 and the "electrical machines" heat exchanger 66, the third branch B3 does not include any other device capable of modifying sen likely the amount of heat accumulated by the heat transfer fluid. The third branch, B3, notably does not include any heat exchangers.

[0098] As shown in [Fig.4], the circuit 12 of the first heat transfer fluid is configured to be able to circulate all of the refrigerant fluid passing through the heating device 54 and the bi-fluid heat exchanger 14 through the "battery" heat exchanger 68 in a third loop L3 of the first heat transfer fluid.

[0099] The circulation of the first heat transfer fluid in the loop L3 allows for example a mode of cooling the batteries in which the air conditioning circuit 10 evaporates the refrigerant in the bifluid heat exchanger 14 to cool the heat transfer fluid circulating in the bifluid heat exchanger 14. The bifluid heat exchanger 14 is then active.

[0100] The circulation of the first heat transfer fluid in the loop L3 also allows for a heating mode of the vehicle's batteries when the electric heating device 54 is active. The two-fluid heat exchanger 14 is then inactive, i.e., it is open to the heat transfer fluid, without significant heat exchange with the refrigerant of the air conditioning circuit 10, for example by completely closing the first expansion device 22.

[0101] The circulation of the first heat transfer fluid in the loop L3 allows a second mode of heating the internal airflow Fi in which the air conditioning circuit 10 operates in internal heat pump mode and in which the heat transfer fluid of the first heat transfer fluid circuit 12 is heated in the battery heat exchanger 68, i.e. a mode of recovering heat from the batteries to heat the passenger compartment.

[0102] The circuit of the first heat transfer fluid includes a first three-way valve 70 connecting the first branch B1 downstream of the two-fluid heat exchanger 14, the fourth branch B4 upstream of the "battery" heat exchanger 68, and the upstream end of the second branch B2. The first three-way valve 70 allows the circulation of the first heat transfer fluid to the second branch B2, and thus the circulation of the first heat transfer fluid in the second loop B2, or to the fourth branch B4, and thus the circulation of the first heat transfer fluid in the third loop B3.

[0103] As illustrated in [Fig. 2], the circuit 12 of the first heat transfer fluid includes a fifth branch B5 equipped with an expansion vessel 60 and a radiator 72 arranged in an external airflow (Fe). A downstream end of the fifth branch B5 is connected to an upstream end of the third branch B3, and an upstream end of the fifth branch B5 is connected to a downstream end of the third branch B3.

[0104] The expansion vessel 60 is located in a different branch of the circuit.

[0105] As illustrated in [Fig.4], the circuit of the first heat transfer fluid is thus configured to be able to circulate, in a fourth loop of the first heat transfer fluid L4, the entire heat transfer fluid passing through the heat exchanger "electrical machines" 66 through the external radiator 72 and the second pump 64, in particular so as to allow passive cooling of the heat transfer fluid passing through the heat exchanger "electrical machines" 66 by cooling in the external radiator 72.

[0106] The circulation of the first heat transfer fluid in the fourth loop L4 allows passive cooling of the electric motor by evacuating heat from the electric motor into the heat transfer fluid 12 through the heat exchanger electric machines 66, then evacuating heat into the outside airflow Fe through the external radiator 72.

[0107] The circuit 12 of the first heat transfer fluid includes a second three-way valve 80 connecting the third branch B3 downstream of the heat exchanger "electrical machines" 66, the fourth branch B4 upstream of the heat exchanger "batteries" 68 and the fifth branch B5 upstream of the external radiator 72.

[0108] The second three-way valve 80 allows the heat transfer fluid to be selected alternatively to the fourth branch B4 to form the second loop L2 of circulation of the first heat transfer fluid or to the fifth branch B5 to form the fourth loop L4 of circulation of the first heat transfer fluid.

[0109] Furthermore, as illustrated in [Fig.5], the circuit described above allows the circulation of the first heat transfer fluid simultaneously in the second loop L2 of the first heat transfer fluid and in the third loop L3 of circulation of the first heat transfer fluid.

[0110] The flow rate in each of the loops L2 and L3 is adjusted by the flow rate of their respective pump 52, 64.

[0111] The two loops L2 and L3 have in common the heat exchanger batteries 68, in which the flow rate of the first heat transfer fluid is the sum of the flow rate of the first heat transfer fluid in each of the two loops L2 and L3.

[0112] The circulation of the first heat transfer fluid simultaneously in loops L2 and L3 allows a third mode of heating the internal airflow in which the bi-fluid heat exchanger is active to recover heat from the batteries and / or the electric motor 66 and / or the electric heating device 54 if the latter is active.

[0113] The [Fig.6] is a schematic view which represents a circuit of the first heat transfer fluid which equips the thermal management system made according to another aspect of the invention, and which is intended to operate in cooperation with the air conditioning circuit of the [Fig.1].

[0114] The circuit 12 of the first heat transfer fluid includes a sixth branch B 6 connecting the fifth branch B5 upstream of the external radiator 72 and the fourth branch B4 downstream of the heat exchanger "batteries" 68.

[0115] The circuit of the first heat transfer fluid includes a third three-way valve 82 connecting the fourth branch B4 downstream of the "batteries" heat exchanger 68, the second branch B2 and the sixth branch B6, in particular so as to connect or not the batteries heat exchanger to the external radiator 72.

[0116] The circuit 12 of the first heat transfer fluid also includes a fourth valve 84 connecting the fourth branch B4 downstream of the "batteries" heat exchanger (68), the third valve (82) and the third branch (B3) upstream of the "electrical machines" heat exchanger (66).

[0117] The third and fourth valves 82, 84 make it possible in particular to prevent the circulation of the first heat transfer fluid from the third loop L3 of the first heat transfer fluid to the fourth loop of the first heat transfer fluid L4 by preventing the first heat transfer fluid from one loop L3 to the other L4 by the sixth branch B6 and by the third branch B3.

[0118] The circuit 12 of the first heat transfer fluid also includes a seventh branch B7 connecting the first branch B1 upstream of the heating device 54 and the fifth branch B5 downstream of the external radiator 72.

[0119] The circuit 12 of the first heat transfer fluid is thus configured, as illustrated in [Fig.7], to allow, in addition to the circulation modes previously illustrated which remain possible, the circulation of the first heat transfer fluid in a fifth outlet L5 of the first heat transfer fluid in which the entire fluid passing through the heat exchanger "batteries" 68 passes through the external radiator 72, in particular by passing through the seventh branch B7 and the sixth branch B6, in particular so as to allow the passive cooling of the first heat transfer fluid passing through the heat exchanger "batteries" 68 by cooling in the external radiator 72. In this configuration, the fourth valve 84 prevents the circulation of the first heat transfer fluid towards the third branch B3 and the third valve 82 prevents the circulation of the first heat transfer fluid towards the second branch B2.Furthermore, the third valve 83 and the third valve 84 connect the sixth branch B6 with the fourth branch B4.

[0120] As illustrated in [Fig.7], the circulation in the fifth loop is for example carried out jointly with the circulation of the first heat transfer fluid in the fourth loop B4. The flow rate of the first heat transfer fluid in the external radiator then corresponds to the sum of the flow rates in the first pump 52 (or in the heat exchanger for the batteries 68) and in the second pump 64 (or in the heat exchanger for the electrical machines 66).

[0121] It is thus possible to passively cool batteries and machines electrical (or power electronics).

[0122] Horn illustrated on [Fig.8], the circuit 12 of the first heat transfer fluid is configured to allow the circulation of the first heat transfer fluid in the third loop L4 of the first heat transfer fluid in which all of the fluid passing through the heat exchanger "electric machines" 66 passes through the external radiator 72 and in the fourth loop L4 of the first heat transfer fluid in which all of the refrigerant passing through the heat exchanger "batteries" 68 passes through the heating device 54 and the bi-fluid heat exchanger 14.

[0123] In this circulation mode, the third valve 82 and the fourth valve 84 prevent the circulation of the first heat transfer fluid between the third and fourth loops of the first heat transfer fluid L3, L4 by preventing the fluid from passing through the sixth branch B6 towards the external radiator 72 and through the third branch B3

[0124] Note that if no valve prevents the circulation of the first heat transfer fluid through the seventh branch B7, such a valve is in fact useless because the conservation of flow in each loop implies a natural non-circulation in the seventh branch B7.

[0125] As illustrated in [Fig. 9], the circuit 12 of the first heat transfer fluid is configured so that the fluid circulating through the "batteries" heat exchanger 68 passes upstream, on the one hand, through the heating device 54, the two-fluid heat exchanger 14 and the first pump 54, thus forming the third loop L3 of the first heat transfer fluid, and on the other hand, through a sixth loop L6 of the first heat transfer fluid, passing through the "electrical machines" heat exchanger 66 and the second pump 64, so as to allow, in particular, a heat recovery mode by the refrigerant circuit, the heat being supplied by the "electrical machines" heat exchanger 66, the electric heating device 54 and / or the "batteries" heat exchanger (68). This mode of operation is analogous to the mode of operation of [Fig. 5], but using, in the mode of operation of [Fig. 68], the circuit 12 of the first heat transfer fluid is configured so that the fluid circulating through the "batteries" heat exchanger 68 passes upstream, on the one hand, through the heating device 54, the two-fluid heat exchanger 14 and the first pump 54, thus forming the third loop L3 of the first heat transfer fluid, and on the other hand, through a sixth loop L6 of the first heat transfer fluid, passing through the "electrical machines" heat exchanger 66 and the second pump 64, so as to allow, in particular, a mode of heat recovery by the refrigerant circuit, the heat being supplied by the "electrical machines" heat exchanger 66, the electric heating device 54 and / or the "batteries" heat exchanger (68). This mode of operation is analogous to the mode of operation of [Fig. 5], but using, in the mode of operation of [Fig. 5], the fluid circulating through the first heat transfer fluid 68 passes upstream, on the one hand, through the heating device 54, the two-fluid heat exchanger 14 and the first pump 54, thus forming the third loop L3 of the first heat transfer fluid.7], the return of the first heat transfer fluid to the sixth loop via the second branch B2 and then via the seventh branch B7, which can minimize heat losses compared to the operating mode of [Fig.5].

Claims

1. Claims Thermal management system for a hybrid or electric vehicle, the thermal management system comprising a reversible air conditioning circuit (10) in which a refrigerant circulates and comprising a two-fluid heat exchanger (14) arranged jointly on a circuit (12) of a first heat transfer fluid, the air conditioning circuit (10) successively comprising, in a main loop, a compressor, a first heat exchanger (20) arranged to exchange calories with a heat transfer fluid, directly or indirectly, the heat transfer fluid being for example an internal air flow (Fi) blown into the passenger compartment of the vehicle, an expansion member (33) for the refrigerant and a second heat exchanger (34) arranged to exchange calories with a heat transfer fluid, directly or indirectly, the heat transfer fluid being for example an internal air flow (Fi) blown into the passenger compartment of the vehicle,the circuit (12) of the first heat transfer fluid comprising:, - a first branch (Bl) comprising a first pump (52), a device (54) for heating the first heat transfer fluid and the two-fluid heat exchanger (14), - a second branch (B2) of which an upstream end is connected directly to the first branch (Bl) downstream of the two-fluid heat exchanger (14) and of which a downstream end is connected directly to an upstream end of the first branch (Bl), in which the circuit of the first heat transfer fluid (12) comprises: - a third branch (B3) which comprises a second pump (64) and a third heat exchanger (66), for example an "electrical machines" heat exchanger (66) which allows the exchange of heat between power electronics and / or an electric motor of the vehicle, on the one hand, and the first heat transfer fluid, on the other hand, - a fourth branch (B4) which comprises a fourth heat exchanger (68), for example a "battery" heat exchanger (68) which is configured to allow the exchange of heat between batteries of the vehicle and the first heat transfer fluid, the fourth branch (B4) comprising an upstream end which is connected to a downstream end of the first branch (B1) and a downstream end which is connected to the second branch (B2), an upstream end of the fourth branch (B4) being connected to a downstream end of the third branch (B3), and a downstream end of the fourth branch (B4) being connected to an upstream end of the third branch (B3), -a fifth branch (B5) equipped with a radiator (72) arranged in an external air flow (Fe), a downstream end of the fifth branch (B5) being connected to an upstream end of the third branch (B3) and an upstream end of the fifth branch (B5) being connected to a downstream end of the third branch (B3), the circuit being configured to be able to circulate, in a fourth loop of the first heat transfer fluid (L4), all of the first heat transfer fluid passing through the "electrical machines" heat exchanger (66) through the external radiator (72) and the second pump (64), in particular so as to allow passive cooling of the first heat transfer fluid passing through the "electrical machines" heat exchanger (66) by cooling in the external radiator (72), - a sixth branch (B6) connecting the fifth branch (B5) upstream of the external radiator (72) and the fourth branch (B4) downstream of the “battery” heat exchanger (68), and a seventh branch (B7) connecting the first branch (B1) upstream of the heating device (54) and the fifth branch (B5) downstream of the external radiator (72), - the circuit (12) of the first heat transfer fluid being configured so that, in a first mode of heating the internal air flow (Fi): - in a first loop (L1) of the first heat transfer fluid, the first heat transfer fluid passing through the heating device (54), for example the entirety of the fluid passing through the heating device (54), passes through the two-fluid heat exchanger (14) and into the first pump (52), the heating device (54) and the two-fluid heat exchanger (14) being active, in particular so as to heat the refrigerant passing through the two-fluid heat exchanger (14), and,simultaneously or independently of the circulation of the first heat transfer fluid in the first loop (L1) of the first heat transfer fluid, the circuit is configured so that, in a second loop (L2) of the first heat transfer fluid, the first heat transfer fluid passing through the "batteries" heat exchanger (68), for example the entirety of the first heat transfer fluid passing through the "batteries" heat exchanger (68) passes through the "electrical machines" heat exchanger (66) and into the second pump (64), in particular so as to heat the first heat transfer fluid passing through the "batteries" heat exchanger (68) using the heat recovered by, the heat exchanger "electric machines" (66).

2. System according to the preceding claim, in which, in the first branch (B1), the two-fluid heat exchanger (14) is arranged downstream of the device (54) for heating the first heat transfer fluid (14), preferably directly downstream.

3. System according to the preceding claim, in which, in addition to the first pump (52), the device (54) for heating the first heat transfer fluid and the two-fluid heat exchanger (14), the first branch (B1) does not include any other device capable of significantly modifying the quantity of heat accumulated by the first heat transfer fluid.

4. System according to the preceding claim, in which the second branch (B2) does not include any device capable of significantly modifying the quantity of heat accumulated by the first heat transfer fluid.

5. System according to the preceding claim, in which the circuit (12) of the first heat transfer fluid is configured to be able to circulate all of the refrigerant fluid passing through the heating device (54) and the dual-fluid heat exchanger through the “battery” heat exchanger (68) in a third loop (L3) of the first heat transfer fluid, in particular so as to heat the first heat transfer fluid passing through the “battery” heat exchanger (68) when the heating device (54) is active or alternatively so as to cool the first heat transfer fluid passing through the “battery” heat exchanger (68) when the dual-fluid heat exchanger (14) is active.

6. System according to any one of the preceding claims, in which the circuit (12) of the first heat transfer fluid comprises a first three-way valve (70) connecting the first branch (B1) downstream of the two-fluid heat exchanger (14), the fourth branch (B4) upstream of the “battery” heat exchanger (68) and the upstream end of the second branch (B2).

7. System according to any one of the preceding claims, in which the circuit (12) of the first heat transfer fluid comprises a second three-way valve (80) connecting the third branch (B3) downstream of the “electrical machines” heat exchanger (66), the fourth branch (B4) upstream of the “batteries” heat exchanger (68) and the fifth branch (B5) upstream of the external radiator (72).

8. System according to any one of the preceding claims, in which the circuit (12) of the first heat transfer fluid is configured to allow the circulation of the first heat transfer fluid in a fifth loop (L5) of the first heat transfer fluid in which all of the fluid passing through the “battery” heat exchanger (68) passes through the external radiator (72), in particular by passing through the seventh branch (B7) and the sixth branch (B6), in particular so as to allow the passive cooling of the first heat transfer fluid passing through the “battery” heat exchanger (68) by cooling in the external radiator (72).

9. System according to the preceding claim, in which the circuit (12) of the first heat transfer fluid is configured to allow, in parallel with the fifth loop (L5) of the first heat transfer fluid, the circulation of the first heat transfer fluid in the fourth loop (L4) of the first heat transfer fluid in which all of the fluid passing through the “electrical machines” heat exchanger (66) passes through the external radiator (72), the fluid circulating in the fifth branch (B5) being divided between the seventh branch (B7) towards the battery heat exchanger (68) and the third branch (B3) towards the “electrical machines” heat exchanger (66), in particular so as to simultaneously allow the passive cooling of the first heat transfer fluid passing through the “battery” heat exchanger (68) and of the first heat transfer fluid passing through the “electrical machines” heat exchanger (66) by cooling in the external radiator (72).

10. System according to the preceding claim, in which the circuit (12) of the first heat transfer fluid comprises a third three-way valve (82) connecting the fourth branch (B4) downstream of the “battery” heat exchanger (68), the second branch (B2) and the sixth branch (B6), in particular so as to connect or not the battery heat exchanger (68) to the external radiator (72).

11. System according to any one of claims 8 to 10 taken together with claim 5, in which the circuit (12) of the first heat transfer fluid is configured to allow the circulation of the heat transfer fluid in the third loop (L4) of the first heat transfer fluid in which the entirety of the fluid passing through the “electrical machines” heat exchanger (66) passes through the external radiator (72) and in the fourth loop of the first heat transfer fluid in which the entirety of the refrigerant fluid passing through the heat exchanger "batteries" (68), passes through the heating device (54) and the two-fluid heat exchanger (14.

12. System according to the preceding claim, in which the circuit (12) of the first heat transfer fluid comprises a fourth valve (84) connecting the fourth branch (B4) downstream of the “batteries” heat exchanger (68), the third valve (82) and the third branch (B3) upstream of the “electrical machines” heat exchanger (66), in particular so as to be able to prevent with the third and fourth valves (82, 84) the circulation of the first heat transfer fluid from the third loop (L3) of the first heat transfer fluid to the fourth loop of the first heat transfer fluid (L4) via the sixth branch (B6) and via the third branch (B3).

13. System according to the preceding claim, in which the circuit (12) of the first heat transfer fluid is configured to allow the fluid circulating through the “battery” heat exchanger (68) to pass upstream on the one hand into the heating device (54), the two-fluid heat exchanger (14) and the first pump (54) thereby forming the third loop (L3) of the first heat transfer fluid and on the other hand into a sixth loop (L6) of the first heat transfer fluid passing through the “electrical machines” heat exchanger (66) and the second pump (64), so as to allow in particular a heat recovery mode by the refrigerant fluid circuit, the calories being supplied by the “electrical machines” heat exchanger (66), the heating device (54) and / or the “battery” heat exchanger (68).

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