FR3118313A1 - Electricity storage battery and assembly comprising air conditioning and such a battery - Google Patents

Abstract

Electricity storage battery and assembly comprising air conditioning and such a battery The battery (1) comprises:- a battery casing (5) having a heat exchange wall (71) of a heat-conducting material ; - a dielectric fluid circuit (73) configured to circulate a dielectric fluid (69) in contact with the electricity storage cells (3) and in contact with an internal side of the heat exchange wall (71) ; - a heat removal circuit (75), configured to circulate a heat transfer fluid in contact with an external side of the heat exchange wall (71). Figure for abstract: 3

Description

Electricity storage battery and assembly comprising air conditioning and such a battery

The present invention generally relates to electricity storage batteries whose cells are cooled by immersion in a dielectric fluid.

It is necessary in such a battery to cool the dielectric fluid. One possibility for this is to circulate the dielectric fluid to a radiator arranged at the front of the vehicle.

This solution is expensive.

In this context, the invention aims to provide a battery which does not have the above defect.

To this end, the invention relates to a vehicle electricity storage battery, the battery comprising:

- electricity storage cells;

- a battery casing comprising an internal volume in which the electricity storage cells are housed, the battery casing having a heat exchange wall made of a heat-conducting material;

- a dielectric fluid;

- a dielectric fluid circuit configured to circulate the dielectric fluid in contact with the electricity storage cells and to circulate the dielectric fluid in contact with an internal side of the heat exchange wall;

- a heat removal circuit, configured to circulate a heat transfer fluid in contact with an external side of the heat exchange wall.

Thus, the heat exchange between the dielectric fluid and the heat transfer fluid is carried out at the level of a wall of the battery casing. The dielectric fluid circuit is drastically simplified, since the dielectric fluid only circulates inside the battery casing. The volume of dielectric fluid is also reduced, which contributes to limiting the cost.

The circulation of the heat transfer fluid in contact with the heat exchange wall can be arranged quite easily, which contributes to reducing the overall cost.

The battery may also have one or more of the characteristics below, considered individually or in all technically possible combinations:

- the heat exchange wall directly delimits the internal volume;

- the battery casing comprises a supporting structure on which the electricity storage cells rest, the heat exchange wall belonging to the supporting structure and delimiting the supporting structure towards the internal volume;

- the dielectric fluid circuit comprises lower channels in which the dielectric fluid is directly in contact with the electricity storage cells and directly in contact with the heat exchange wall;

- the battery comprises a spacer structure through which the electricity storage cells rest on the heat exchange wall, the spacer structure delimiting the lower channels;

- the spacer structure comprises a plurality of longitudinal profiles spaced transversely from each other and defining between them the lower channels, the longitudinal profiles being connected to each other by bars arranged in the lower channels;

- the supporting structure comprises a lower plate extending opposite the heat exchange plate, the heat removal circuit comprising heat transfer fluid circulation channels provided between the heat exchange plate and the lower plate of the support structure, along which the heat transfer fluid is in direct contact with the heat exchange plate;

- the support structure comprises fins rigidly fixed to the heat exchange plate and to the lower plate of the support structure, the fins defining between them the circulation channels of the heat transfer fluid;

- the heat transfer fluid is air.

According to a second aspect, the invention relates to an assembly comprising an air conditioning and an electricity storage battery having the above characteristics, the air conditioning comprising an outside air intake, a air connected to the outside air intake and a conditioning circuit in which a conditioning fluid circulates, the conditioning circuit comprising a conditioning fluid evaporator having a first side in which the conditioning fluid circulates and a second side interposed in the air duct, the air duct being, downstream of the second side, fluidly connected to an air outlet opening into a passenger compartment of the vehicle and to a coolant fluid inlet of the heat evacuation circuit.

The assembly may also have the characteristic below:

- the air conditioning comprises an interior air intake opening into the passenger compartment of the vehicle and an additional air duct connecting the interior air intake to the heat transfer fluid inlet of the heat evacuation circuit.

Other characteristics and advantages of the invention will emerge from the detailed description given below, by way of indication and in no way limiting, with reference to the appended figures, among which:

there is a partial sectional and perspective view of the battery of the invention, only part of the electricity storage cells being shown to reveal the dielectric fluid circuit;

there is a partial perspective view of the battery of the , showing the coolant outlets;

there is a sectional view of part of the battery of the , showing an alternative embodiment of the bars of the spacer;

there is a perspective view of the battery strut of the ;

there is a top view of the lower part of the battery, schematically illustrating the circulation of the dielectric fluid;

there is a schematic top view of the lower part of the battery support structure of the , showing the fins and the coolant circuit;

there is a simplified schematic representation of an assembly comprising an air conditioning unit and an electricity storage battery according to the invention; And

there is a simplified schematic representation of a variant of the entire .

The electric battery represented in FIGS. 1 to 6 is intended to equip a vehicle, typically a motor vehicle such as a car, a bus or a truck.

The vehicle is for example a vehicle propelled by an electric motor, the motor being electrically powered by the electric battery. As a variant, the vehicle is of the hybrid type and thus comprises a heat engine and an electric motor powered electrically by the electric battery. According to yet another variant, the vehicle is propelled by a heat engine, the electric battery being provided to electrically supply other equipment of the vehicle, for example the starter, the lights, etc.

The electricity storage battery 1 comprises a plurality of electricity storage cells 3 (FIGS. 1, 3 and 5) and a battery casing 5 (FIGS. 1 and 3) comprising an internal volume 7 in which the cells are housed. electricity storage 3.

Typically, the electricity storage cells 3 are arranged so as to form one or more modules 9.

The number of modules 9 depends on the electricity storage capacity of battery 1. In the example of the , the battery comprises sixteen modules 9. However, the battery may comprise more than sixteen modules or less than sixteen modules.

The electricity storage cells 3 are of any suitable type: lithium cell of the Lithium-Ion Polymer (Li-Po), Lithium-Iron-Phosphate (LFP), Lithium Cobalt (LCO), Lithium Manganese (LMO) type, Nickel-Manganese-Cobalt (NMC), or NiMH type cell (Nickel-Metal-Hydride in English).

For example represented, each module 9 comprises twelve cells. However, the number of cells in the same module is in a variant different from twelve: it is either greater than twelve or less than twelve.

Typically, each electricity storage cell 3 is prismatic in shape.

It thus has two large faces 11,13 and four small faces 15, 17, 19, 21 connecting the two large faces 11, 13 to each other (Figures 1 and 3).

The two large faces 11, 13 are parallel and opposite to each other. The four small faces 15, 17, 19, 21 are perpendicular to each other and are perpendicular to the large faces 11, 13.

The small face 15 carries two electrical contacts 23 ( ).

In the same module 9, the electricity storage cells 3 are juxtaposed transversely. The transverse direction is represented by an arrow T in the figures.

The cells 3 are in contact with each other by their respective large faces 11,13.

The small faces 15 bearing the electrical contacts face the same side and are juxtaposed. The electrical contacts of the different cells of the same module 9 are connected to each other, so as to place the electricity storage cells 3 in series and/or in parallel. The connectors for connecting the electrical contacts of the cells are not shown in the figures.

Each module 9 therefore has the shape of a parallelepiped block having an elongated shape in the transverse direction T.

As seen on the , the casing 5 comprises a supporting structure 25 on which the cells 3 rest.

The envelope 5 also includes a lid 27.

The supporting structure 25 and the cover 27 delimit between them the internal volume 7.

Typically, the supporting structure 25 of the casing faces downwards, that is to say towards the running surface of the vehicle. Cover 27 faces upwards.

In the example shown, the support structure 25 has the shape of a substantially flat plate, constituting a rigid frame supporting the cells 3. As a variant, the support structure has the shape of a tray, or any other suitable shape.

Cover 27 is concave towards supporting structure 25.

The supporting structure 25 and the cover 27 are in sealed contact with each other along a peripheral line. In the example shown, the support structure 25 is rectangular, and the contact line is also rectangular.

In the example shown, the support structure 25 and the cover 27 are fixed to each other by means of clamps 29 and screws, not shown.

The clamps 29 are for example U-sections.

The clamps 29 are here arranged along each of the sides of the support structure 25. Each clamp 29 clamps the edge of the lower part 25 with the outgoing flange of the cover 27.

The internal volume 7 is divided into a plurality of compartments 37.

3 cells are received in 37 compartments.

Preferably, each compartment 37 receives a module 9.

The compartments 37 are elongated transversely.

The compartments 37 are for example arranged in two rows, as illustrated in the .

Advantageously, and as visible more clearly on the , the battery 1 comprises a plastic material 41.

The plastic material 41 is typically molded onto beams, not shown, integral with the supporting structure 25.

Each compartment 37 is delimited by an internal surface 43.

The inner surface 43 of the compartment 37 comprises a side surface 45 with a closed contour, a lower surface 47 and an upper surface 49 (FIGS. 1 and 3).

The side surface 45 of the internal surface 43 of the compartment 37 is substantially parallel to a main direction, materialized in the figures by arrows P. This main direction P is substantially perpendicular to the running surface when the battery is installed on board the vehicle .

The lower surface 47 constitutes the bottom of the compartment 37. It is defined by the supporting structure 25 of the casing 5. It is substantially perpendicular to the main direction P.

The lateral surface 45 comprises two large surfaces 51 facing each other, falling within planes containing the transverse direction T and the main direction P (FIGS. 1 and 5). It also comprises two small surfaces 53 facing each other, falling within respective planes containing the longitudinal L and main P directions ( ).

Side surface 45 is typically defined by plastic material 41.

Top surface 49 is defined by cover 27.

According to a variant not shown, a block made of said plastic material is integral with cover 27 of casing 5 and defines upper surface 49.

As seen in particular on the , the lid 27 has an upper bottom 59, an edge 61 erected over the entire periphery of the upper front 59, extended by an outgoing flange 63 resting against the supporting structure 25.

The plastic material 41 forms a block 65 in one piece, projecting towards the cover 27 from the supporting structure 25.

This block 65 defines a frame 65C and a plurality of internal partitions 65I inside the frame 65C (FIGS. 1 and 5).

The frame 65C and the internal partitions 65I delimit between them the compartments 37.

An outer side surface 65S1 of the frame 65C is pressed against the raised edge 61 of the cover 27 of the casing 5 ( ). The upper edge 65S2 of the frame 65C and the upper edges 65S3 of the internal partitions 65I ( and 5) are pressed against the upper bottom 59 of the lid 27 of the casing 5, possibly with the interposition of the block of plastic material in contact with the upper bottom 59 of the lid 27.

The plastic material 41 is for example foamed. The foam typically has a density between 0.050 and 1.000 kilograms per liter, and preferably between 0.1 and 0.900 kilograms per liter.

Typically the foam is polyurethane foam. As a variant, the foam is a polyurethane/polyurea foam, poly(EVA) (ethylene-vinyl acetate in French), polyethylene, polypropylene, or even a silicone foam obtained either by the reactive route or by the gaseous expansion route. using for example steam.

Preferably the foam is a closed cell foam.

In all cases, the plastic material 41 is advantageously covered with a skin 67 of a material that is impervious to the dielectric fluid cooling the cells of the battery 1 (FIGS. 1 and 3).

This skin 67 covers at least the surfaces of the plastic material 41 likely to be in contact with the dielectric fluid. Preferably, it covers all the free surfaces of the plastic material 41.

It covers at least the side surface 45 of each compartment 37.

The skin 67 is a layer of epoxy resin (RTM or Resin Transfer Molding in French) or other, or a layer of acrylic, or polyurea, or polyurethane.

Alternatively, the plastic material 41 is not foamed.

In this case, it may not be covered with a skin.

The plastic block is typically foamed. The foam then typically has a density between 0.050 and 1.000 kilograms per liter, and preferably between 0.1 and 0.900 kilograms per liter.

The block of foamed plastic material, integral with the lid, is then advantageously also covered with a skin of a material that is impervious to the dielectric fluid.

Typically, the block of plastic material integral with the cover is made of the same material as the plastic material 41.

As seen in particular on the , the cells are arranged in such a way that the small face 15 bearing the electrical contacts of each cell 9 faces the upper bottom 59 of the cover 27. The small face 17, opposite the small face 15, faces the supporting structure 25.

The small faces 19 and 21 are pressed against the side surface 45 of the internal surface 43 of the compartment 37, and more precisely against the two large surfaces 51 of the side surface 45.

The large faces 11 and 13 of the two cells 9 located at the transverse ends of the module 3 bear against the small surfaces 53 of the side surface 45.

Battery 1 includes dielectric fluid 69.

The dielectric fluid 69 is in thermal contact with the electricity storage cells 3. It circulates in direct contact with the electricity storage cells 3.

The dielectric fluid 69 makes it possible to cool the electricity storage cells 3. It can optionally also heat the electricity storage cells 3.

The dielectric fluid is for example a refrigerant liquid, fluorinated or not, or a mineral oil, or a modified vegetable oil.

To allow heat exchanges with the outside of battery 1, battery casing 5 comprises a heat exchange wall 71 made of a material that conducts heat.

This material is for example aluminum or an aluminum alloy, steel or stainless steel.

The heat exchange wall 71 directly delimits the internal volume 5.

Typically, the heat exchange wall 71 belongs to the load-bearing structure 25 and delimits the load-bearing structure 25 towards the internal volume 5.

The heat exchange wall 71 thus constitutes the upper wall of the supporting structure 25.

It defines the lower surface 47 of the or each compartment 37.

Plate 71 is flat.

The battery 1 further comprises a dielectric fluid circuit 73 configured to cause the dielectric fluid 69 to circulate in contact with the electricity storage cells 3 and to cause the dielectric fluid 69 to circulate in contact with an internal side of the heat exchange wall. heat 71.

Battery 1 also includes a heat removal circuit 75, configured to circulate a heat transfer fluid in contact with an external side of the heat exchange wall 71.

The dielectric fluid 69 is in thermal contact with the heat transfer fluid through the heat exchange wall 71.

The heat generated by the electricity storage cells 3 is transferred by the dielectric fluid 69 to the heat exchange wall 71, crosses the heat exchange wall by conduction, and then is evacuated out of the battery 1 by the heat transfer fluid.

As visible in FIGS. 1 and 3, the dielectric fluid circuit 73 comprises lower channels 77 in which the dielectric fluid 69 is directly in contact with the electricity storage cells 3 and directly in contact with the heat exchange wall. heat 71.

The lower channels 77 extend between the small undersides 17 of the cells and the heat exchange wall 71.

To this end, the battery 1 comprises a spacer structure 79 through which the electricity storage cells 3 rest on the heat exchange wall 71.

Thus, the weight of the electricity storage cells 3 is taken up by the spacer structure 79, which transmits it to the heat exchange wall 71.

The spacer structure 79 rests on the heat exchange wall 71.

It is for example glued to the heat exchange wall, or simply placed without fixing.

The spacer structure 79 delimits the lower channels 77.

To do this, the spacer structure 79 comprises a plurality of longitudinal profiles 81 spaced transversely from each other and defining between them the lower channels 77.

The longitudinal profiles 81 are connected to each other by bars 83 arranged in the lower channels 77.

The longitudinal profiles 81 are all identical.

They have a section a constant cross section over their entire length, except at their two opposite ends.

For example, this section is trapezoidal ( ). The large base of the trapezium rests on the heat exchange wall 71. The electricity storage cells 3 rest on the small base. The two inclined sides are symmetrical to each other and delimit the lower channels 77.

Each longitudinal profile 81 extends over substantially the entire width of the compartment 37.

The opposite longitudinal ends 85 of the profile each have a shape chosen to fit into the angle between the large surface 51 and the heat exchange wall 71. Thus, each longitudinal end 85 fills this angle, with no gap between the profile longitudinal 81 and the heat exchange wall 71 or the large surface 51. Leaks of dielectric liquid from one lower channel 77 to another are thus limited in the corners.

In the example shown (see for example), the plastic material 41 constituting the large surface 51 is connected to the lower surface 47 of the compartment in a curved manner. It forms a fillet 87. The skin 67 extends slightly beyond the fillet on the bottom of the housing. Its extreme edge 89 forms a low step on the heat exchange wall 71.

The longitudinal ends 85 of each section 81 are each spatula, to fit into the hollow of the fillet 87. They have towards the heat exchange wall 71 each a hollow shape 91, in which is housed the extreme edge 89 of the skin.

The strips 83 are of transverse orientation.

Each longitudinal profile 81 is rigidly fixed to the neighboring profile(s) by a plurality of strips 83 regularly distributed longitudinally along the profile.

In the example shown in the , these strips 83 are placed in the same plane parallel to the heat exchange wall 71.

Considered in section in a plane perpendicular to the transverse direction, each bar 83 has an oval or bi-convex shape, with a major longitudinal axis. Such a shape makes it possible not to generate excessive counter-pressure for the flow of the dielectric fluid.

According to a variant represented on the , the major axis is tilted, so as to generate more turbulence in the flow of dielectric fluid. This makes it possible to increase the heat exchanges by convection between the dielectric fluid and the electricity storage cell on the one hand, and between the dielectric fluid and the heat exchange wall on the other hand.

According to a variant not shown, the strips 83 are placed at different heights relative to the heat exchange wall 71. This also makes it possible to increase the heat exchanges by convection between the dielectric fluid and the electricity storage cell of on the one hand, and between the dielectric fluid and the heat exchange wall on the other hand.

These two variants can be combined with each other.

The strips 83 are integral with the longitudinal sections 81.

For example, the spacer structure 79 is obtained by injection or by molding.

It is for example made of a plastic material, advantageously of polyamide, polypropylene or any other suitable plastic material.

Alternatively, it is made of aluminum or an aluminum alloy.

The dielectric fluid circuit 73 comprises, for each electricity storage cell 3, a circulation channel 91 which extends along the three small faces 17, 19, 21 of the cell 3 which do not carry the electrical contacts 23 .

The circulation channel 91 therefore has a U-shape, with a first lateral section 93 along the small face 19, a second lateral section 95 along the small face 21, the lower channel 77 being the central section and connecting the side sections 93, 95 to each other.

The lateral sections 93, 95 are delimited between the electricity storage cells 9 and the plastic material 41.

The side sections 93, 95 are typically recessed reliefs defined in the plastic material 41. They are open towards the cells 3.

The first lateral section 93 is dug in one of the large surfaces 51 of the lateral surface 45, and the second lateral section 95 is dug in the other large surface 51 of the lateral surface 45 of the internal surface 43 of the compartment 37.

The first lateral sections 93 serving two neighboring cells 3 are separated from each other by flat fields 97 which rest against the small faces 19 of the cells. Similarly, the second lateral sections 95 serving two neighboring cells 3 are separated from each other by flat fields 97 which bear against the small faces 21 of the cells.

The dielectric fluid circuit 73 comprises a dielectric fluid distribution manifold 99 and a dielectric fluid discharge manifold 101 (FIGS. 1 and 5).

The collectors 99, 101 are for example delimited between the plastic material 41 and the cover 27.

In the example represented, the collectors 99 and 101 are formed along the upper edge 65S3 of the frame 65C.

The dielectric fluid circuit 73 further comprises a dielectric fluid distribution sub-manifold 103 for each module 9, and a dielectric fluid evacuation sub-manifold 105 for each module 9 ( ).

The distribution sub-manifold 103 fluidically connects the distribution manifold 99 to the circulation channels 91 serving the cells 3 of the corresponding module.

The distribution sub-collectors 103 are represented schematically on the . We see that they are all parallel to each other, and extend transversely from the distribution manifold 99.

Each distribution sub-manifold 103 is for example a recessed relief made in the cover 27.

The first lateral section 93 of each circulation channel 91 opens into the corresponding distribution sub-manifold 103.

The evacuation sub-collector 105 fluidically connects the evacuation collector 101 to the circulation channels 91 serving the cells 3 of the corresponding module.

The evacuation sub-collectors 105 are shown schematically in the . We see that they are all parallel to each other, and extend transversely from the exhaust manifold 101.

Each evacuation sub-collector 105 is for example a recessed relief made in the lid.

The second lateral section 95 of each circulation channel 91 opens into the corresponding evacuation sub-collector 105.

The dielectric fluid circuit 73 further comprises a circulation device 107 such as a pump (FIGS. 7 and 8), arranged to recirculate the dielectric fluid from the evacuation manifold 101 into the distribution manifold 99.

The circulation member 107 is advantageously housed in the battery casing 5.

The support structure 25 comprises a lower plate 109 extending opposite the heat exchange plate 71.

The lower plate 109 is for example substantially flat, and of the same size as the heat exchange plate 71.

The lower plate 109 faces the running surface of the vehicle. It delimits the supporting structure 25 towards the running surface.

An empty space 111 separates the heat exchange plate 71 from the lower plate 109, substantially over the entire surface of these plates.

The clamps 29 extend over the entire periphery of the support structure 25 and close the empty space 111 over its entire periphery.

The carrier structure 25 further comprises peripheral fins 113 ( ) securing a peripheral edge of the heat exchange plate 71 to the peripheral edge of the lower plate 109. These edges face each other.

The peripheral fins 113 are placed in the empty space 111 and form a ring 114 around it.

The peripheral fins 113 are configured to define in the support structure 25 very resistant zones in the event of a side impact. This strength is achieved by properly choosing the orientation of the fins, the material, the thickness, the spacing of the fins from each other, the shape of the fins, etc.

The load-bearing structure 25 further comprises fins 115 rigidly fixed to the heat exchange plate 71 and to the lower plate 109.

The fins 115 are placed in the empty space 111.

More precisely, the fins 115 are placed inside the crown 114.

The fins 115 are arranged in two zones 117, separated from each other by a region 119 without fins.

The finless region 119 is rectilinear and entirely crosses the volume inside the crown 114. It is elongated in a first direction D1.

Zones 117 are symmetrical to each other.

Each zone 117 is delimited by the region 119 and by the crown 114. Fins 115 are arranged throughout the zone 117.

The fins 115 are parallel to each other and extend along a second direction D2, perpendicular to the first direction D1.

The heat removal circuit 75 comprises heat transfer fluid circulation channels 121 formed between the heat exchange plate 71 and the lower plate 109, along which the heat transfer fluid is in direct contact with the heat exchange plate. heat 71.

The fins 115 delimit between them the circulation channels 121.

Each circulation channel 121 extends from region 119 to crown 114.

More precisely, as seen in the , the heat removal circuit 75 includes a coolant inlet 122 opening into the empty space 111.

The coolant inlet 122 emerges at one end of the region 119, which acts as a fluid distribution manifold in the circulation channels 121.

Fluid discharge orifices 123 are made in the clamps 59.

Thus, the heat transfer fluid leaving the circulation channels 121 passes through the crown 112 and leaves the supporting structure through the discharge orifices 123.

The number and size of the holes is chosen according to the flow of fluid to be evacuated.

The fins 115 are for example formed, in each zone 117, of a metal sheet folded into slots.

They are of any suitable type: straight and smooth, straight and corrugated, “offset” type, or wave-shaped.

The fins 115 are thin, the thickness being between 0.1 and 0.3 mm. The fins 115 are for example made of aluminum or an aluminum alloy, or of carbon steel or stainless steel.

As a variant, for reasons of mechanical strength, these fins 115 can reach thicknesses of 1 mm.

The fins 115 are brazed or glued to the heat exchange plate 71 and/or to the lower plate 109.

They are arranged according to a pitch varying from 3 mm to 14 mm. In other words, they are regularly spaced and separated from each other by a distance of between 3 and 14 mm. The pitch is chosen according to the quantity of heat to be evacuated.

Advantageously, the compartments 37 are all located on the region 119 or on the zones 117.

As a variant, the circulation channels 121 cover only part of the heat exchange plate 71. Certain compartments are not located on a surface of the plate 71 directly cooled by the heat transfer fluid. In this case, the circulation channels 121 cover at least 50% of the surface of the heat exchange plate 71, preferably at least 75%.

Typically, the heat transfer fluid is air.

This air comes from outside the vehicle and is released outside the vehicle after passing through the supporting structure.

The circulation of the dielectric fluid and of the heat transfer fluid in the battery above will now be described.

The dielectric fluid is set in motion by the circulation member 107. It flows into the distribution manifold 99, then into the distribution sub-manifolds 103, and from each sub-manifold 103, into the distribution channels. circulation 91.

In each channel 91, the dielectric fluid first follows the first lateral section 93, then the lower channel 77, then the second lateral section 95.

The dielectric fluid is then collected in the evacuation sub-manifold 105, then circulates to the evacuation collector 101 and returns to the circulation member 107.

The dielectric fluid circulates in direct contact with the three small faces 17, 19, 21 of each cell 3, and evacuates the heat given off by the cell 3. Passing through the lower channel 77, it transfers this heat to the heat transfer fluid through the wall of heat exchange 71.

The heat transfer fluid is set in motion by a device external to battery 1.

It enters the supporting structure through the coolant inlet 122, and flows along the region 119. It is distributed from the region 119 into the circulation channels 121 and flows in contact with the wall of heat exchange 71.

Leaving the circulation channels 121, the heat transfer fluid passes through the crown 114 and is discharged into the environment through the discharge orifices 123.

It should be noted that the overall coefficient of heat transfer from cell 3 to the dielectric fluid is lower than the overall coefficient of heat transfer from the dielectric fluid to the heat exchange wall 71. This results from the constitution of cell 3 itself. Thus, it is advantageous to have a heat exchange surface between the dielectric fluid and the cell – the three small faces of the cell – which is greater than the heat exchange surface between the dielectric fluid and the wall of the cell. heat exchange.

The battery 1 described above is advantageously integrated into an assembly further comprising an air conditioning 127, as shown in the .

The air conditioning 127 is typically provided to treat the air blown inside the passenger compartment 128 of the vehicle.

The air conditioning 127 comprises an outside air intake 129, an air duct 131 fluidly connected to the outside air intake 129 and a conditioning circuit 132 in which a conditioning fluid circulates.

The conditioning circuit 132 is of known structure.

It comprises in series a compressor 133, a condenser 135 and an expander 137.

The condenser is typically a radiator placed on the front of the vehicle, the conditioning fluid giving up its heat to the outside air.

The conditioning circuit 132 comprises a conditioning fluid evaporator 139 having a first side in which the conditioning fluid circulates and a second side interposed in the air duct 131.

The first side is interposed in series between the expander 137 and the compressor 133.

The evaporator 139 is arranged so that the liquid conditioning fluid leaving the expansion valve is vaporized in the evaporator, transferring cold temperatures to the outside air circulating in the air duct 131.

The air duct 131, downstream of the second side of the evaporator 139, is divided into two branches, a first branch 140 fluidly connected to at least one air outlet 141 opening into the passenger compartment 128 of the vehicle and a second branch 143 fluidly connected to the heat transfer fluid inlet 122 of the heat removal circuit 75.

The air conditioning 127 further comprises an air circulation device 145, for example a fan, interposed in the air duct 131. For example, it is arranged immediately downstream of the outside air intake 129.

The air conditioning 127 further comprises a first controlled valve 147 interposed on the first branch 140 and a second controlled valve 149 interposed on the second branch 143.

The assembly further includes a controller 151, for example a computer, configured to control the first and second valves 147 and 149, the circulation device 149 and the conditioning circuit 132.

The controller 151 is programmed to, in current use of the vehicle, keep the second valve 149 closed.

Current use means a life situation in which the heating of the battery 1 is low. This is typically the case when battery 1 generates moderate electrical power, and/or when the outside temperature is not excessively hot. Moderate electrical power is understood here to mean, for a battery having a capacity of C kWh, a power for example less than 0.5 C kW. This corresponds to a situation where the vehicle is traveling at normal speed.

In this case, the controller 151 is programmed to control the first valve 147, the circulation device 149 and the conditioning circuit 132 according to the air conditioning needs of the passengers traveling in the passenger compartment.

The controller 151 is programmed to keep the second valve 149 open when the heating of coil 1 is strong.

This is typically the case in the case of rapid recharging of battery 1, or when the outside temperature is high. A rapid recharge corresponds for example to a recharge at 2 C.

In this case, the controller 151 is programmed to put the circulation device 149 and the conditioning circuit 132 into operation. The first valve 147 is kept closed, or is opened according to the air conditioning needs of the passengers occupying the passenger compartment. .

According to a variant embodiment illustrated in the , the air conditioning 127 comprises an interior air intake 153 opening into the passenger compartment 128 of the vehicle and an additional air duct 155 fluidly connecting the interior air intake 153 to the heat transfer fluid inlet 122 of the circuit heat dissipation 75.

Typically, the air outlet or outlets 141 are placed towards the front of the passenger compartment, and the interior air intake 153 towards the rear of the passenger compartment.

Thus, when the first valve 147 is open and air is blown into the passenger compartment, at least part of this air leaves the passenger compartment through the interior air intake and is used to cool the battery 1. This makes it possible to recover part of the energy of the conditioning circuit 132 for cooling the battery 1.

The battery described above has multiple advantages.

As indicated above, the dielectric fluid circuit is particularly simple and short, since the dielectric fluid only circulates inside the battery casing.

The fact that the heat exchange wall directly delimits the internal volume contributes to this simplicity.

Integrating the heat exchange wall into the supporting structure is particularly convenient and economical, since the energy storage cells rest on this structure and are therefore conveniently positioned to create a heat exchange through the exchange wall heat.

When the dielectric fluid circuit comprises lower channels in which the dielectric fluid is directly in contact with the storage cells and directly in contact with the heat exchange wall, the battery is particularly compact and the heat transfers between the cells and the heat exchange wall are particularly effective.

The spacer structure allows these lower channels to be made very conveniently. In particular, the bars placed in the lower channels make it possible to increase the turbulence in the dielectric fluid circulating in the lower channels, and therefore make it possible to improve heat transfer.

When the support structure comprises a lower plate extending opposite the heat exchange plate, the heat removal circuit can be very conveniently arranged inside the support structure. This makes the battery even more compact. The heat transfer fluid can circulate in direct contact with the heat exchange plate, which facilitates heat transfer.

When the supporting structure comprises fins, these can be advantageously used to create the circulation channels for the heat transfer fluid. These fins also increase the rigidity of the supporting structure.

Because the heat transfer efficiency in the coil is very high, it is possible to use air as the heat transfer fluid. This simplifies the heat transfer fluid circuit and makes the battery more economical.

Integrating the battery into an assembly including an air conditioning circuit allows the conditioning circuit to be used to cool the electricity storage cells when needed. This is particularly interesting during fast battery charges.

This integration can be done very economically, as it only requires the addition of a pipe and a valve.

During fast charging, the vehicle is stationary and connected to the electrical network. Using the conditioning circuit to cool the battery does not penalize battery life.

Adding an interior air intake to capture stale air from the cabin and use it for battery cooling helps to optimize fuel efficiency.

The battery can have multiple variations, which can be implemented individually or in combination.

Electric cells are not necessarily prismatic cells. They can be cylindrical, or of any other type.

The battery casing is not necessarily filled with a material delimiting the cell reception compartments and the dielectric fluid circuit. The compartments can be delimited by walls made of a plastic material, or in any other way. These walls can be shaped to create dielectric fluid circulation channels in contact with the electricity storage cells.

The collectors and sub-collectors can be ducts or can be made in any other suitable way.

The heat exchange wall does not necessarily belong to the supporting structure. It can be provided on the cover or on another structure.

The supporting structure is not necessarily a flat plate. It can have the shape of a tray, a cradle or any other shape.

Typically, the battery is rigidly attached to the vehicle structure by the support structure. In other words, the weight of the battery and the forces applied to the battery are taken up by the supporting structure and transmitted to the structure of the vehicle by the supporting structure.

The circulation of the heat transfer fluid in contact with the heat exchange wall may not be channeled by fins. For example, a stamped plate is placed in the empty space between the heat exchange plate and the bottom plate. This stamped plate has partitions creating a circulation path in baffles from a heat transfer fluid inlet to one or more heat transfer fluid outlets.

The load-bearing structure, in addition to the heat exchange wall and the lower wall, may include other elements: protective shield against external attacks, stiffening elements, etc.

The heat transfer fluid is not necessarily air. Alternatively, the heat transfer fluid is a liquid such as glycol water. In this case, the heat evacuation circuit is connected to an existing cooling system on board the vehicle, for example the engine cooling circuit.

In the case where the heat transfer fluid is air, the heat evacuation circuit is not necessarily integrated with the air conditioning of the vehicle. As a variant, an exterior air intake and a dedicated circulation device are provided, independent of the air conditioning for the passenger compartment. The circulation device circulates the air from the air intake to the heat transfer fluid inlet.

Claims (11)

Vehicle electricity storage battery, the battery (1) comprising:
- electricity storage cells (3);
- a battery casing (5) comprising an internal volume (7) in which the electricity storage cells (3) are housed, the battery casing (5) having a heat exchange wall (71) made of a heat conducting material;
- a dielectric fluid (69);
- a dielectric fluid circuit (73) configured to circulate the dielectric fluid (69) in contact with the electricity storage cells (3) and to circulate the dielectric fluid (69) in contact with an internal side of the heat exchange wall (71);
- a heat removal circuit (75), configured to circulate a heat transfer fluid in contact with an outer side of the heat exchange wall (71). Electricity storage battery according to claim 1, in which the heat exchange wall (71) directly delimits the internal volume (5). Electricity storage battery according to Claim 1 or 2, in which the battery casing (5) comprises a support structure (25) on which the electricity storage cells (3) rest, the heat (71) belonging to the supporting structure (25) and delimiting the supporting structure (25) towards the internal volume (5). Electricity storage battery according to claim 3, in which the dielectric fluid circuit (73) comprises lower channels (77) in which the dielectric fluid (69) is in direct contact with the electricity storage cells (3 ) and directly in contact with the heat exchange wall (71). Electricity storage battery according to claim 4, wherein the battery (1) comprises a spacer structure (79) through which the electricity storage cells (3) rest on the heat exchange wall (71), the spacer structure (79) delimiting the lower channels (77). Electricity storage battery according to claim 5, in which the spacer structure (79) comprises a plurality of longitudinal profiles (81) spaced transversely from one another and defining between them the lower channels (77), the longitudinal profiles (81 ) being connected to each other by bars (83) arranged in the lower channels (77). Electricity storage battery according to any one of Claims 3 to 6, in which the supporting structure (25) comprises a lower plate (109) extending opposite the heat exchange plate ( 71), the heat removal circuit (75) comprising channels (121) for the circulation of the coolant fluid provided between the heat exchange plate (71) and the lower plate (109) of the supporting structure (25) , along which the coolant is in direct contact with the heat exchange plate (71). Electricity storage battery according to claim 7, in which the supporting structure (25) comprises fins (115) rigidly fixed to the heat exchange plate (71) and to the lower plate (109) of the supporting structure (25), the fins (115) defining between them the circulation channels (121) of the heat transfer fluid. An electricity storage battery according to any preceding claim, wherein the heat transfer fluid is air. Assembly comprising an air conditioner (127) and an electricity storage battery (1) according to any one of the preceding claims, the air conditioner (127) comprising an outside air intake (129), a air duct (131) connected to the outside air intake (129) and a conditioning circuit (132) in which a conditioning fluid circulates, the conditioning circuit (132) comprising an evaporator (139) of conditioning having a first side in which the conditioning fluid circulates and a second side interposed in the air duct (131), the air duct (131) being, downstream of the second side, fluidly connected to an outlet of air (141) opening into a passenger compartment (128) of the vehicle and to a coolant fluid inlet (122) of the heat evacuation circuit (75). Assembly according to Claim 10, in which the air conditioning (127) comprises an interior air intake (153) opening into the passenger compartment (128) of the vehicle and an additional air duct (155) connecting the interior air intake. indoor air (153) to the coolant inlet (122) of the heat removal circuit (75).