ELECTRIC MOTOR VEHICLE FEATURING AN AIR-WATER HYBRID BATTERY COOLING DEVICE

Abstract

The invention relates to an electric motor vehicle, comprising a battery tray (100) including a battery module (1) and a cooling device (10) allowing heat exchange between a heat exchanger (4) and a first heat transfer fluid, between the heat exchanger (4) and a cooling plate (2) including cooling channels (20) conveying a second heat transfer fluid, between the cooling plate (2) and the battery module (1), the heat exchanger (4) including cooling fins (40) parallel to a longitudinal direction of the vehicle, the cooling device (10) including a lower casing (7) transversely surrounding the heat exchanger (4), constituting a channel (70) for the circulation of the first fluid and open at front (71) and rear (72) ends, and including a movable flap (6) for closing the flow of the first heat transfer fluid, to partially or completely close the front (71) or rear (72) end,on vehicle control systems. Figure 2,

Description

Title of the invention: ELECTRIC MOTOR VEHICLE COMPRISING AN AIR-WATER HYBRID BATTERY COOLING DEVICE

[0001] The invention relates to an electric or hybrid motor vehicle, comprising a battery tray controlled by control means and comprising at least one battery module and a gas-liquid hybrid battery cooling device, comprising on the one hand a cooling plate comprising an upper surface arranged to bring each said battery module into contact therewith, said cooling plate being arranged for heat exchange between each said battery module and a liquid heat transfer fluid conveyed in a closed circuit and through cooling conduits which said cooling plate comprises or carries, and on the other hand an exchanger pressed against said cooling plate on the side opposite said upper surface or merged with said cooling plate,said exchanger being arranged for heat exchange between said liquid heat transfer fluid circulating in said cooling conduits and a gaseous heat transfer fluid circulating around cooling fins which said exchanger comprises.

[0002] The invention relates to the field of energy storage and distribution equipment for electric or hybrid motor vehicles, such as battery trays, cooling plates, in particular mixing liquid cooling and gaseous cooling, in particular by air.

[0003] The battery tray comprises a mechanical structure made up of side members and cross members on which the cooling plate and the battery modules are fixed. A protective screen is generally positioned under the cooling plate and separated from it by an air gap acting as a thermal insulator. This screen therefore plays two roles: mechanical protection and thermal barrier.

[0004] The battery modules are fixed to the structure of the battery tray, as well as the cooling plate. These components are brought into contact by a thermal paste which improves the thermal exchanges between the cooling plate and the Li-ion modules.

[0005] The cooling plate is traversed by a heat transfer fluid whose temperature is regulated by the heating, ventilation and air conditioning circuit known as the HVAC circuit (from the English "heating, ventilation and air-conditioning") or the vehicle's heat pump. A mechanical protection plate also provides thermal insulation. This thermal insulation is useful when external temperatures are very high (for example, radiation from bitumen in hot weather with a temperature that can exceed 50°C). It conditions the cooling to the efficiency of the cold plate, and the heat capacity offered by all the material that makes up the battery. Under these conditions and in certain life situations, the potential for absorption of calories by the ambient air is not exploited.

[0006] The present invention proposes to better exploit the cooling potential offered by the movement of air under the vehicle.

[0007] To achieve this objective, the invention proposes an electric or hybrid motor vehicle, comprising a battery tray controlled by control means and comprising at least one battery module and a gas-liquid hybrid battery cooling device, comprising on the one hand a cooling plate comprising an upper surface arranged to bring each said battery module into contact therewith, said cooling plate being arranged for heat exchange between each said battery module and a liquid heat transfer fluid conveyed in a closed circuit and through cooling conduits that said cooling plate comprises or carries, and on the other hand an exchanger pressed against said cooling plate on the side opposite said upper surface or merged with said cooling plate,said exchanger being arranged for heat exchange between said liquid heat transfer fluid circulating in said cooling conduits and a gaseous heat transfer fluid circulating around cooling fins which said exchanger comprises.

[0008] According to the invention, said cooling fins are arranged parallel to the direction of circulation of said motor vehicle, and said battery cooling device comprises a lower casing surrounding at least said exchanger with which it defines a longitudinal channel for circulation of said gaseous heat transfer fluid and open at a front end and at a rear end in said direction of circulation, and comprises at least one movable closing flap for the flow of said gaseous heat transfer fluid, said at least one flap being arranged to partially or completely close said front end or said rear end, said control means being arranged to control the position of said at least one flap on the basis of temperature information from sensors included in said battery tray.

[0009] Thanks to the invention, it is very simple to control, thanks to a movable flap in a flow of gaseous heat transfer fluid, in particular the ambient air of the vehicle, the heat exchanges are regulated with a cooling plate carrying a liquid heat transfer fluid, to optimally adjust the temperature at the level of each battery module carried by this cooling plate.

[0010] Advantageously, said cooling ducts are parallel to said cooling fins.

[0011] This ensures optimal exchange between the two flows of heat transfer fluids.

[0012] Advantageously, said gaseous heat transfer fluid is air, and said channel is arranged in an open area so that any displacement movement said vehicle causes the movement of an air flow in said channel.

[0013] This makes use of the air circulation under the moving vehicle to help cool the battery tray.

[0014] Advantageously, said lower casing is thermally insulating.

[0015] It is thus possible to stabilize the temperature in the channel, and in the contact zone between the exchanger and the cooling plate.

[0016] In a variant, said cooling ducts are integrated into said cooling plate or integral with said cooling plate.

[0017] This variant is suitable for the manufacture of a cooling plate by casting or injection, or of a prismatic cooling plate to which cooling pipes are attached.

[0018] In another variant, said cooling plate comprises, on a lower surface facing said exchanger, lower grooves, and said exchanger comprises, on an upper surface facing said cooling plate, upper grooves, and said cooling ducts are delimited by said lower grooves and said upper grooves.

[0019] This variant makes it possible to simplify the manufacture of the cooling plate.

[0020] Advantageously, said cooling plate comprises, on a first upper side opposite said exchanger, ribs which are arranged, on the one hand to position each said battery module, and on the other hand to stiffen said cooling plate and reinforce its mechanical strength.

[0021] This guarantees good mechanical strength of the battery modules, while limiting deformation of the assembly.

[0022] Advantageously, said ribs comprise notches, or lugs, arranged to cooperate in a complementary manner with lugs, respectively notches, which each said battery module comprises to ensure its positioning and its maintenance.

[0023] Thus the battery modules are very precisely positioned and maintained.

[0024] Advantageously, said battery cooling device comprises an upper casing, surrounding said cooling plate and each said battery module, and which forms a complementary closed bell with said cooling plate.

[0025] This avoids temperature variations in the area of ​​the battery modules.

[0026] Advantageously, said upper casing is thermally insulating.

[0027] This makes it possible to stabilize the temperature in the area of ​​the battery modules.

[0028] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates a motor vehicle according to the invention, comprising control means, and a battery tray comprising a battery module, and a battery cooling device, with double liquid-gas flow, and comprising a shutter controlled by the control means; - [Fig.2] illustrates schematically and in perspective this cooling device housing, which comprises a lower casing and an upper casing which surround the battery module placed on a cooling plate comprising cooling conduits conveying a liquid heat transfer fluid, and an exchanger placed under the latter and exchanging energy with a gaseous heat transfer fluid constituted by the ambient air, guided in a channel of the lower casing which can be closed by the controlled flap, here shown in the open position; - [Fig.3] schematically illustrates the cooling device of [Fig.2], with the shutter in the closed position, preventing the passage of ambient air into the channel; - [Fig.4] schematically illustrates a cross-section of this same device cooling, at the battery module level; - [Fig.5] illustrates the exchanger schematically and in perspective; - [Fig.6] illustrates schematically and in perspective the cooling plate dissement; - [Fig.7] illustrates schematically and in perspective the lower casing.

[0029] The invention aims to improve the thermal regulation of an electric vehicle battery, by controlling the thermal exchanges with the ambient air.

[0030] For this purpose, it uses a new cooling plate, called a cold plate, which is arranged to allow both cooling by a heat transfer liquid, and regulation via a flap (as a function of the temperature of the ambient air under the cold plate) of an air flow on the base of the cooling plate, which locally includes fins promoting heat exchanges.

[0031] This cold plate structure also provides rigidity to the system, and thus makes it possible to lighten the reinforcements (spars, crosspieces) found in standard batteries or serving as a structural frame / structure.

[0032] The cooling device specific to the invention comprises a controllable air cooling system (via a flap) which supplements the liquid cooling circuit.

[0033] A self-supporting cold plate integrates mechanical strength (rigidity) and cooling functions. The cooling plate alone replaces an entire mechanically welded assembly, which makes it possible to eliminate a large number of fixing parts, which reduces the cost and mass of the assembly.

[0034] The invention relates more particularly to a 1000 electric motor vehicle or hybrid, comprising, as visible in [Fig.l], a battery tray 100, controlled by control means 200 that the motor vehicle 1000 comprises. This battery tray 100 comprises at least one battery module 1, and a battery cooling device 10. This battery cooling device 10 is a hybrid gas-liquid cooling device, more particularly air-water. An orthogonal trihedron XYZ is linked to the vehicle 1000: a longitudinal direction X parallel to the straight-line rolling direction, a vertical direction Z according to the local gravity field, and a transverse direction Y orthogonal to the X and Z directions.

[0035] [Fig-2] illustrates a battery tray 100 according to the invention. The cooling device battery module 10 comprises a cooling plate 2, which is arranged to support each battery module 1 on a first upper side 21, in the upward vertical direction Z, and which comprises or carries an exchanger 4, on a second lower side 22 facing the ground in the road position of the vehicle 1000, and opposite the first upper side 21. This exchanger 4 is arranged for a heat exchange with a first heat transfer fluid, in particular a first gaseous heat transfer fluid, in particular air.

[0036] The cooling plate 2 and the exchanger 4 can form a single-piece assembly, or, as shown non-limitingly in [Fig. 2], two separate components fixed to one another, a lower surface 22 of the cooling plate 2 cooperating by contact with an upper surface 42 of the exchanger 4.

[0037] More particularly, the cooling plate 2 comprises, on its first upper side 21, ribs 3, which are arranged, on the one hand to position each battery module 1, and on the other hand to stiffen the cooling plate 2 and reinforce its mechanical strength. Advantageously, these ribs 3 comprise notches 31, or lugs, arranged to cooperate in a complementary manner with lugs 11, respectively notches, which each battery module 1 comprises, thus perfectly positioned and locked in an XY plane parallel to the ground.

[0038] More particularly, the exchanger 4 comprises cooling fins 40 parallel to each other and extending in the longitudinal direction X of the vehicle 1000, that is to say parallel to the direction of circulation of the motor vehicle 1000. These cooling fins 40 also contribute to the mechanical strength of the cooling plate 2, when the cooling plate 2 and the exchanger 4 are fixed to each other. More particularly still, these cooling fins 40 are in one piece with the exchanger 4.

[0039] More particularly, the cooling plate 2 and the exchanger 4 are mechanically integral. More particularly still, these cooling fins 40 are in one piece with the single-piece assembly comprising the cooling plate 2 and the exchanger 4.

[0040] The hollow zones of the cooling fins 40 define channels 41 arranged for the circulation of the first heat transfer fluid, in particular air, in particular ambient air, during the movement of the vehicle 1000 in the longitudinal direction X.

[0041] The cooling plate 2 also comprises cooling conduits 20, arranged to convey in a closed circuit a second heat transfer fluid, different from the first heat transfer fluid, and in particular a heat transfer liquid, in particular and not limited to coolant.

[0042] These cooling ducts 20 can be arranged in different ways: integrated into the thickness of the cooling plate 2, attached to one face of the cooling plate 2 for example in the form of tubes or the like, or even arranged at least partially in the form of lower grooves 23 on the lower surface 22 of the cooling plate 2 as visible in [Fig.2] and in [Fig.4] in a non-limiting variant; the exchanger 4 can also comprise, on the surface of its upper part 42 in contact with the lower surface 22 of the cooling plate 2, upper grooves 43 cooperating with the lower grooves 23 to form the cooling ducts 20.

[0043] Advantageously, a lower casing 7 surrounds, on the second lower side 22 of the cooling plate 2, the exchanger 4 with its cooling fins 40, so as to form, with these cooling fins 40, a channel 70 for circulation of the first heat transfer fluid, in particular an air circulation channel, between an inlet at a front end 71 located on the front side of the vehicle 1000, and an outlet at a rear end 72 located on the rear side of the vehicle 1000, in the longitudinal direction X. More particularly, this lower casing 7 is a thermally insulating casing.

[0044] The cooling conduits 20 are advantageously arranged to convey the second heat transfer fluid parallel to the flow of first heat transfer fluid circulating in the channel 70 for circulation of the first heat transfer fluid, so as to allow optimal heat exchange.

[0045] According to the invention, the cooling fins 40 are arranged parallel to the direction of circulation of the motor vehicle 1000, and the battery cooling device 10 comprises such a lower casing 7 surrounding at least the exchanger 4 with which it defines this longitudinal channel 70 for circulation of the gaseous heat transfer fluid and open at a front end 71 and at a rear end 72 according to the direction of circulation, and comprises at least one flap 6 for movable closure of the flow of the gaseous heat transfer fluid, this at least one flap 6 being arranged to partially or completely close the front end 71 or the rear end 72, the control means 200 being arranged to control the position of this at least one flap 6 on the base temperature information from sensors included in the battery tray 100.

[0046] Thus, for regulating the cooling by the gaseous heat transfer fluid, in particular air, when the vehicle 1000 is running, the battery cooling device 10 comprises a flap 6 arranged for the total or partial blocking of the channel of the first heat transfer fluid, in particular the air circulation channel, at its inlet as visible in [Fig.2], or at its outlet in another variant not illustrated. Advantageously, the temperature sensors located at the battery modules 1 and / or the cooling plate 2, and / or in the channel 70 for circulation of the gaseous heat transfer fluid, in particular the air circulation channel, and / or in at least one cooling duct 20. In a variant not illustrated, the battery cooling device 10 comprises a first flap 6 at the inlet at the front end 71 of the channel 70 as visible in [Fig.2], and a second flap 6 at its exit at the rear end 72 of the channel 70. .

[0047] In a variant not illustrated, the control means 200 are arranged to regulate the circulation of the second heat transfer fluid in the cooling conduits 20, in particular and not limited to by using a pump modifying the circulation flow rate of the heat transfer fluid.

[0048] Advantageously, at least the cooling plate 2 and the battery modules 1 are covered by an upper casing 5, in particular a thermally insulating casing. More particularly, this upper casing 5 comprises lower bearing surfaces 50 for vertically holding the battery modules 1, more particularly still, these lower bearing surfaces 50 are surfaces of resilient elements, such as elastomer pads or the like, fixed to the upper casing 5.

[0049] Advantageously, the upper casing 5 and the lower casing 7 are joined, so as to together form an envelope laterally surrounding the battery modules 1, the cooling plate 2, and the exchanger 4.

[0050] Thus, the cooling plate 2 includes cooling conduits 20 for the second heat transfer fluid, in particular and not limited to liquid, more particularly water, and cooling fins 40, in particular air cooling, which make it possible to ensure optimal regulation of the temperature of the battery.

[0051] In a case of low temperature, the cooling fins 40 swept by fresh air (flap 6 open) may be sufficient on their own to maintain an optimal temperature at the level of the cells of the battery modules 1. In this case, the circulation of the heat transfer liquid is not activated, which limits the energy consumption of the vehicle 1000. If in cold weather, the temperature of the battery is not sufficient, the flap 6 is closed, and the battery is heated by the heat transfer liquid for example or by Joule losses when it is used.

[0052] If the battery has a temperature that is too high and the ambient air is able to lower the temperature of the cells, then the flap 6 is open. Conversely, if the ambient air is too hot, it then becomes preferable to close the flap 6, and to ensure cooling only with the heat transfer fluid whose temperature is controlled by a heating, ventilation and air conditioning circuit called an HVAC circuit, or by a heat pump, which the vehicle 1000 includes. The lower casing 7 of the air circuit duct ensures in this configuration a thermal insulation role in addition to the air that has become stagnant and is located between the cooling fins 40 and the lower casing 7.

[0053] The movable flap 6, located at the front or rear of the battery, is actuated by the control means 200, in particular a computer, of the vehicle 1000 which ensure the thermal management of the battery (HVAC control or heat pump). This flap 6 can be more or less open / closed depending on the need. In a particular and non-limiting variant, the movement of the flap 6 is ensured by an electric actuator.

[0054] On the first upper side of the cooling plate 2, the ribs 3 can be limited to positioning points of the battery modules 1, and do not necessarily need to pass right through the battery if the rigidity offered by the rest of the cooling plate 2 provides sufficient rigidity and mechanical strength to the system to prevent it from deforming when driving or during an impact at low speed.

[0055] The upper surface of the cooling plate 2, on the first upper side, is arranged so as to guarantee optimal contact with the battery modules 1, with the inverse reproduction of the lower surface of these battery modules 1; for an economical execution, the lower surface of the battery modules 1 is flat, and the complementary support surface of the cooling plate 2 is also flat.

[0056] The advantages provided by the invention are numerous.

[0057] The invention improves the temperature regulation of the battery. It facilitates operation at an optimal temperature of the cells (~25°C / +30°C) minimizing their internal resistance, and favorable to their longevity.

[0058] Cooling is provided by the second heat transfer fluid, in particular a heat transfer liquid, more particularly water, and supplemented by cooling by a first heat transfer fluid, in particular a heat transfer gas, more particularly air, the two cooling circuits, arranged for heat exchange with each other, being controlled by the vehicle control means for better efficiency of the heat exchanges depending on the living situations (in particular hot / cold ambient temperature, battery stress level).

[0059] The invention contributes to improving the energy efficiency of the vehicle, with an improvement in the efficiency of battery cooling at reduced cost.

[0060] The invention provides gains in energy consumption of the vehicle by reducing the consumption of the HVAC or the heat pump which are less in demand.

[0061] Improved durability of the battery cells is achieved by this improvement of the cooling system.

[0062] A more rigid cold plate guarantees homogeneous contact with the modules, which improves thermal exchanges with the cells.

[0063] The simplification of the battery structure is achieved by limiting the number of components to be assembled. The shapes can be largely optimized for optimal material savings, particularly through the use of foundry processes. The cold plate can thus be obtained in aluminum foundry, for example.

[0064] The integration and fixing of the modules are facilitated. The modules can be screwed into the cold plate, or simply placed and blocked in Z by the battery cover.

[0065] It is possible to remove the screws fixing the cooling plate to the structure, the cold plate being structural.

[0066] The replacement of a composite assembly by a single piece (advantageously a molded piece) allows the elimination of numerous profiles (crossmembers and side members), which leads to an overall simplification of the battery tray.

[0067] The battery modules can be positioned in the battery tray by being guided by preforms obtained in a foundry and then machined.

[0068] In short, the invention improves the efficiency of the cold plate in all life situations. It makes it possible to minimize the sizing of the cooling circuit (HVAC, heat pump) by reducing its stress, and therefore to reduce the mass of the vehicle with equal energy capacity.

[0069] The invention improves the energy efficiency of the vehicle by placing less strain on the vehicle's cooling system (in particular compressor and pumps).

[0070] The cold plate is structural, which limits and simplifies assembly operations. Its structure limits the complexity of the generally mechanically welded system (spar-crossmember) which leads to significant dispersions in functional dimensions.

Claims

Claims

1. Electric or hybrid motor vehicle (1000), comprising a battery tray (100) controlled by control means (200) and comprising at least one battery module (1) and a gas-liquid hybrid battery cooling device (10), comprising on the one hand a cooling plate (2) comprising an upper surface (21) arranged to bring each said battery module (1) into contact therewith, said cooling plate (2) being arranged for heat exchange between each said battery module (1) and a liquid heat transfer fluid conveyed in a closed circuit and through cooling conduits (20) which said cooling plate (2) comprises or carries, and on the other hand an exchanger (4) pressed against said cooling plate (2) on the side opposite said upper surface (21) or merged with said cooling plate (2),said exchanger (4) being arranged for heat exchange between said liquid heat transfer fluid circulating in said cooling ducts (20) and a gaseous heat transfer fluid circulating around cooling fins (40) which said exchanger (4) comprises, characterized in that said cooling fins (40) are arranged parallel to the direction of circulation of said motor vehicle (1000), and in that said battery cooling device (10) comprises a lower casing (7) surrounding at least said exchanger (4) with which it defines a longitudinal channel (70) for circulation of said gaseous heat transfer fluid and open at a front end (71) and at a rear end (72) in said direction of circulation, and comprises at least one flap (6) for movable closure of the flow of said gaseous heat transfer fluid, said at least one flap (6) being arranged to partially or completely close,said front end (71) or said rear end (72), said control means (200) being arranged to control the position of said at least one flap (6) on the basis of temperature information from sensors included in said battery tray (100).,

2. Motor vehicle (1000) according to claim 1 characterized in that said cooling ducts (20) are parallel to said cooling fins (40)

3. Motor vehicle (1000) according to claim 1 or 2 characterized in that said gaseous heat transfer fluid is air, and in that said channel (70) is arranged in an open area so that any movement of said vehicle (1000) causes the movement of an air flow in said channel (70).

4. Motor vehicle (1000) according to any one of claims 1 to 3 characterized in that said lower casing (7) is thermally insulating.

5. Motor vehicle (1000) according to any one of claims 1 to 4 characterized in that said cooling ducts (20) are integrated into said cooling plate (2) or integral with said cooling plate (2).

6. Motor vehicle (1000) according to any one of claims 1 to 4 characterized in that said cooling plate (2) comprises, on a lower surface (22) facing said exchanger (4), lower grooves (23), and in that said exchanger (4) comprises, on an upper surface (42) facing said cooling plate (2), upper grooves (43), and in that said cooling ducts (20) are delimited by said lower grooves (23) and said upper grooves (43).

7. Motor vehicle (1000) according to any one of claims 1 to 6 characterized in that said cooling plate (2) comprises, on a first upper side (21) opposite said exchanger (4), ribs (3) which are arranged, on the one hand to position each said battery module (1), and on the other hand to stiffen said cooling plate (2) and reinforce its mechanical strength.

8. Motor vehicle (1000) according to claim 7 characterized in that said ribs (3) comprise notches (31), or lugs, arranged to cooperate in a complementary manner with lugs (11), respectively notches, which each said battery module (1) comprises to ensure its positioning and its maintenance.

9. Motor vehicle (1000) according to any one of claims 1 to 8 characterized in that said battery cooling device (10) comprises an upper casing (5), surrounding said cooling plate (2) and each said battery module (1), and which forms a complementary closed bell with said cooling plate (2).

10. Motor vehicle (1000) according to claim 9 characterized in that said upper casing (5) is thermally insulating.

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