FR3054730A1 - THERMAL CONTROL DEVICE FOR A BATTERY OF A VEHICLE BY INDIRECT CONTACT - Google Patents

Abstract

The present invention relates to a thermal regulation device for at least one electrical energy storage element, comprising a heat exchanger comprising: at least one circulation duct for a heat transfer fluid; and a sealing wall disposed between said circulation duct and said storage elements, the sealing wall being thermally conductive.

Description

© Publication no .: 3,054,730 (use only for reproduction orders)

©) National registration number: 16 57153 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY

COURBEVOIE © Int Cl ⁸ : H 01 M 10/6554 (2017.01), H 01 M 10/6556, 10/6567

A1 PATENT APPLICATION

©) Date of filing: 07.26.16. © Applicant (s): VALEO THERMAL SYSTEMS (30) Priority: Simplified joint stock company - FR. @ Inventor (s): MULLER JEAN DAMIEN, ROBILLON LIONEL, BARRE BORIS and POURMARIN ALAIN. (43) Date of public availability of the request: 02.02.18 Bulletin 18/05. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): VALEO THERMAL SYSTEMS related: Joint stock company. ©) Extension request (s): © Agent (s): VALEO THERMAL SYSTEMS.

A VEHICLE CONTACT BATTERY

THERMAL REGULATION DEVICE FOR INDIRECT.

FR 3 054 730 - A1 (6 (2 The present invention relates to a thermal regulation device for at least one element for storing electrical energy, comprising a heat exchanger comprising:

at least one conduit for circulation of a heat transfer fluid; and a sealing wall disposed between said circulation duct and said storage elements, the sealing wall being thermally conductive.

i

Thermal regulation device for a vehicle battery by indirect contact

1. Field of the invention

The invention relates to the field of thermal regulation devices for an assembly of at least one battery, and more particularly of a thermal regulation device with heat transfer liquid for a set of at least one battery equipping a motor vehicle, propulsion is provided in whole or in part by an electric motor.

2. Prior art

The thermal regulation of the battery, especially in the field of electric and hybrid vehicles, is an important point. Indeed, the temperature of the battery must be regulated in order to ensure the reliability, the autonomy, and the performance of the vehicle, while optimizing the lifespan of the battery.

In electric or hybrid vehicles, the battery is generally produced in the form of electrical energy storage cells. These energy storage cells are positioned in a protective box and form, with this box, what is called a battery pack.

In order to regulate the temperature of the battery, it is known to use a thermal regulation device. In this connection, reference may be made to document EP 2 599 153 (BAYERISCHE MOTOREN WERKE AG) presenting such a thermal regulation device which uses a heat transfer fluid circulating, for example, by means of a pump in a circuit of conduits. This heat exchanger is positioned directly in contact with the battery, at the bottom of the protective housing, and the heat transfer fluid can thus absorb the heat emitted by the battery in order to cool the latter or, if necessary, provide it with heat if the temperature of the battery is insufficient for its proper functioning.

The heat transfer fluid generally used is ambient air or liquids, for example water, a mixture of water and glycol, or any other similar fluid. As liquids are better thermal conductors than gases, they are a preferred solution because they are more efficient. However, the use of a heat transfer liquid can cause problems, especially in the event of accidents or impacts to the vehicle. For example, leakage and leakage or degradation of the connection elements of the duct circuit can result.

Such a situation is problematic. Indeed, if the heat transfer liquid comes into contact with the electric energy storage cells of the battery pack, supplied with electricity, this can lead to short circuits and other dangerous problems for the driver and passengers (risk of thermal runaway and fire in particular).

Another drawback of the technique described in this document of the prior art lies in the maintenance difficulties encountered during replacement or intervention on the battery. Indeed, these operations require touching the battery, which is in direct contact with the heat exchanger, and there is therefore a risk of damaging the exchanger.

In addition, in the case of direct contact in the presence of a thermal interface material inserted between the exchanger and the battery, the maintenance operations are made laborious by the properties of the thermal interface material which make the removal of the battery relative to the exchanger cannot be done without damaging the latter, due to a suction cup phenomenon between the thermal interface material and the exchanger.

In addition, the development of electric and hybrid vehicles gives rise to new constraints concerning the packaging of electric batteries. In fact, the space dedicated to the heat exchanger is becoming more and more limited and requires the development of new means of maintaining the heat exchanger against the battery to be cooled. For example, document EP 2 599 153 proposes to position a space-saving spring between the multiplicity of tubes of the heat exchanger and the bottom of the protective case of the battery pack, so as to ensure contact, and thus improve the 'heat exchange, between the battery and the exchanger.

One of the aims of the invention is, in at least one embodiment, to remedy the aforementioned drawbacks and to respond to the new constraints imposed in the field.

3. Summary of the invention

To this end, the invention provides a thermal regulation device for at least one electrical energy storage element, comprising a heat exchanger comprising:

• at least one circulation pipe for a heat transfer fluid; and • a sealing wall disposed between said circulation duct and said storage elements, the sealing wall being thermally conductive.

Thus, the device of the invention secures, by means of the sealing wall, the elements for storing electrical energy (for example a battery) relative to the exchanger, in order to protect them in the event of leakage from the exchanger fluid.

The sealing wall is, moreover, configured to have optimal thermal properties so as to facilitate heat exchanges between the electrical energy storage elements and the exchanger.

Thus, the sealing wall makes it possible to obtain an optimal compromise between safety and cooling of the battery.

According to one aspect of the invention, the sealing wall is formed from metallic material, for example aluminum or stainless steel.

According to another aspect of the invention, the sealing wall has a thermal conduction of between 15 W / m.K and 230 W / m.K.

Thus, the sealing wall, which is made of a thermally conductive material, is chosen so as to have a thermal conduction value situated in this interval and favoring the heat exchanges between the energy storage elements and the heat exchanger. heat, through it.

According to one aspect of the invention, the sealing wall is a plate.

According to another aspect of the invention, the surface of the sealing wall located on the side of the electrical energy storage elements follows the shape of these elements.

Thus, the contact between the electrical energy storage elements and the sealing wall is optimal in order to facilitate and improve the heat exchanges.

According to another aspect of the invention, the exchanger comprises two plates fixed together to delimit the duct, the plates comprising a plurality of channels.

Alternatively, the exchanger comprises a tube delimiting the conduit, the tube preferably delimiting a plurality of channels.

Thus, the exchanger conduits have a plurality of channels allowing the circulation of the heat transfer fluid intended to cool or, as necessary, to heat the electrical energy storage elements.

According to one aspect of the invention, the electrical energy storage element is an electrical cell, for example of the cylindrical, prismatic, or pocket type.

According to another aspect of the invention, the thermal regulation device comprises a housing with a housing compartment for the storage element and a housing compartment for the exchanger, the sealing wall separating the two compartments.

Alternatively, the thermal regulation device comprises a housing for housing the electrical energy storage element, the sealing wall being formed by a wall of the housing, the device further comprising a fixed exchanger support wall. on the housing.

Advantageously, the sealing wall acts as a barrier between the compartment of the housing in which the electrical energy storage elements are housed and the compartment in which the heat exchanger is housed. Thus, the compartment receiving the exchanger is therefore either included directly in the housing (the wall delimiting the two compartments of the housing), or it is attached or fixed to the housing, for example by the implementation of a support wall (the sealing wall forming a wall of the housing).

According to yet another aspect of the invention, the fluid is a cooling fluid or a cooling liquid.

4. Figures

Other characteristics and advantages will appear more clearly on reading the following detailed description of several particular embodiments of the invention, given by way of simple illustrative and nonlimiting examples, and of the appended drawings, among which:

Figure 1 shows schematically in cross section a first embodiment of a battery pack according to the present invention;

Figure 2 shows schematically a first embodiment of the means for holding an exchanger in a battery pack;

Figure 3 shows schematically a second embodiment of the means for holding an exchanger in a battery pack;

Figure 4 shows schematically in cross section a second embodiment of a battery pack according to the present invention;

Figure 5 shows schematically a variant of the embodiment of Figure 1;

Figure 6 shows schematically another variant of the embodiment of Figure 1;

FIG. 7A represents an exploded view of a first type of conduit for circulation of the heat-transfer fluid;

Figure 7B is a cross-sectional view of the circulation conduit of Figure 7A, after assembly; and FIG. 8 is a schematic view of a second type of pipe for circulation of the heat transfer fluid.

5. Detailed description of several embodiments of the invention

5.1 General principle of the invention

The invention therefore proposes to optimize the thermal regulation devices of the battery of a hybrid or electric vehicle by the implementation of a sealing wall, within the battery pack, between the battery and the exchanger. heat. Thus, this thermally conductive wall allows heat exchanges between the battery and the exchanger while guaranteeing the sealing of the battery compartment against the risks of leakage of fluid from the exchanger in the event of an accident, for example. The contact, and the heat exchanges, between the battery and the exchanger are therefore made via the sealing wall. This contact is therefore indirect.

5.2 Description of a first embodiment of the invention

In the various figures, unless otherwise indicated, identical elements have the same reference numbers and have the same technical characteristics and operating modes.

Figure 1 illustrates the general principle of the invention, according to a first embodiment, in which a battery pack 1 is shown. This battery pack 1 comprises walls delimiting a housing 10 in which at least one battery 2 is housed. Conventionally, the battery 2 is composed of several cells / electrical storage elements or accumulators connected together.

In order to regulate the temperature of the battery 2, the battery pack 1 is equipped with a heat exchanger 4 having a plurality of conduits 41 for circulation of a heat transfer fluid.

The heat transfer fluid may be of the refrigerant type, that is to say a mixture of water and gas, or else a cooling liquid, that is to say a mixture of water and glycol.

The circulation conduits 41 are obtained, as illustrated in FIGS. 7A and 7B, by assembling two plates 412a, 412b. One of the plates 412a has at least one wall 413, which generally extends along a plane perpendicular to the plane of the plate 412a, and which, when the plates 412a and 412b are fixed together, delimits a plurality of channels 414 circulation of the heat transfer fluid.

In a variant, illustrated in FIG. 8, the circulation conduits 41 are in the form of tubes 415 flat, comprising a plurality of walls 416 delimiting a plurality of channels 417 for circulation of the heat transfer fluid.

In another variant (not shown), it is possible to use conduits 41 for circulation of hybrid fluid, that is to say conduits 41 which are obtained by a combination of plates 412 and tubes 415.

According to the invention, the heat exchanger 4 comprises a sealing wall 3, fixed in sealed manner to the housing 10 of the battery pack 1. According to a first embodiment, illustrated in FIG. 1, the sealing wall 3 is fixed in the housing 10 so as to delimit a battery compartment 11, in which the battery 2 is housed, and an exchanger compartment 12, in which the heat exchanger 4 is housed.

As illustrated in FIG. 1, the battery 2 rests on the upper face of the sealing wall 3, while the conduits 41 for circulation of the fluid extend under the sealing wall 3 and are in contact with the lower face of the wall 3 through the latter. The heat exchanges between the battery 2 and the exchanger 4 therefore take place at the level of the sealing wall 3. The heat transfer fluid circulating in the conduits 41 of the exchanger 4 can thus absorb the heat energy from the battery 2 at through the sealing wall 3.

The sealing wall 3 serves as a separator or barrier, and protects the battery 2 in the event of a leak in the heat transfer fluid contained in the exchanger 4, such a leak being able to be caused, for example, by an impact or an accident.

The sealed attachment of the wall 3 to the housing 10 can in particular be carried out by welding or by overmolding of the housing 10 on the sealing wall 3. Thus, in the event of a leak at the exchanger 4, the heat transfer fluid cannot spread that in the exchanger compartment 12, sealed by the sealing wall 3. There is therefore no risk for the heat transfer fluid to come into contact with the battery 2. The present invention therefore greatly reduces the risks of short- circuit or other electrical problems which may occur in the event of contact between the battery 2 and the heat transfer fluid.

In order to optimize the heat exchanges between the batteries 2 and the heat exchanger 4, the contact must be optimal between, on the one hand, the sealing wall 3 and the battery 2, and on the other hand, between the sealing wall 3 and the heat exchanger 4. To do this, the sealing wall 3 has a flat bottom surface, called the first surface, facing the heat exchanger 4, so that the conduits 41 for circulation are pressed against the wall 3 so as to provide optimal contact between the exchanger 4 and the wall 3.

Furthermore, the upper surface of the sealing wall 3 oriented towards the battery 2, called the second surface, opposite the first surface, has a shape corresponding to the shape of the electrical energy storage cells so as to also provide a optimal contact between the battery 2 and the sealing wall 3.

Thus, the sealing wall 3 is configured to improve the contact on the one hand with the exchanger 4 and on the other hand with the battery 2 in order to promote / maximize the heat exchanges.

In this first embodiment, the battery 2 rests on the sealing wall 3, by gravity. The heat exchanger 4 being located under the sealing wall 3, it is therefore necessary to implement means for holding the conduits 41 for circulation of the fluid against the sealing wall 3 in order to achieve optimal contact between these two elements.

FIGS. 2 and 3 illustrate two embodiments of the means for holding the conduits 41 against the sealing wall 3.

Figure 2 is a partial view of the battery pack 1 of Figure 1 in which the housing 10 has not been shown for clarity. In this example, the means for holding the conduits 41 for circulation of the fluid against the sealing wall 3 are in the form of a thermal adhesive 6. This thermal adhesive 6, of the thermal adhesive type based on Epoxy, or silicone without limitation of the type of load, for example, allows a solid fixing of the conduits 41 on the sealing wall 3 while promoting heat exchanges between the conduits 41 and the wall 3. In a variant (not illustrated), it is possible to braze or weld, rather than glue, the ducts 41 for circulation to the wall 3.

Figure 3 is a partial view of the battery pack 1 of Figure 1 in which the housing 10 has also not been shown for clarity. In this example, the means for holding the conduits 41 for circulating the fluid against the sealing wall 3 are in the form of an elastic element 7. Thus, each of the conduits 41 for circulating the fluid is held against the wall d sealing 3 by means of an elastic element 7 which provides a pushing force F thus making it possible to press / hold the conduits 41 against the wall 3. Preferably, the elastic element 7 is in the form of a spring.

In order to further improve the contact and the heat exchanges between the conduits 41 and the sealing wall 3, an interlayer 8 made of a material having a high thermal conductance is here inserted / interposed between the conduits 41 and the wall 3. More in particular, the interlayer 8 can be in the form of a grease, a pad or carpet (“pad” in English), or a bonding paste (“gap filler” in English), in particular.

In another variant (not shown), it is possible to combine the use of a thermal adhesive 6 and an elastic element 7 when the mechanical stresses are too great and cannot be supported by thermal adhesive 6 alone , or the elastic element 7 alone.

5.3 Description of a second embodiment of the invention

FIG. 4 illustrates a second embodiment of the invention in which a battery pack 1 is shown. The battery pack 1 is, similarly to the first embodiment, capable of receiving at least one battery 2 and a heat exchanger

4.

In this second embodiment, the housing 10 is formed by a plurality of walls and is capable of receiving the battery 2. The exchanger 4 comprises a sealing wall 3 which is an integral part of the housing 10. In other words , the sealing wall 3 here forms the bottom wall of the housing 10, thus delimiting the battery compartment 11 in which the battery 2 is housed. The exchanger compartment 12, receiving the heat exchanger 4, is delimited by setting work of a support wall 5 which is fixed to the sealing wall 3 and to the housing 10.

In this example, the seal between the two compartments 11 and 12 of the battery pack 1 can in particular be obtained by bringing the support wall 5 and the sealing wall 3 onto the housing 10 into contact and tightening in the presence of a or more seals (not shown). To do this, a clamping element (not shown), for example in the form of a frame or a set of legs, is arranged around the periphery of the support wall 5 and is fixed to the housing 10. using screws, for example.

It is also possible to fix the housing 10, the sealing wall 3 and the support wall 5 by welding, for example. Any other fixing technique making it possible to guarantee the tightness of the battery compartment 11 relative to the exchanger compartment 12 can, of course, be implemented here without departing from the principle of the invention.

In this example, it is possible to dispense with the implementation of the means for holding the conduits 41 for circulation of the fluid against the sealing wall 3. In fact, as illustrated in FIG. 4, the support wall 5 is configured to allow the insertion of the conduits 41 between the support wall 5 and the sealing wall 3, while allowing optimal maintenance of the conduits 41 against the sealing wall 3. An insert 8, as described above, can also be implemented.

However, this embodiment leaves the possibility of providing for the implementation of the holding means described above and illustrated in FIGS. 2 and 3, when the support wall 5 delimits an exchanger compartment 12 of a dimension greater than the dimension of the conduits 41.

5.4 Other aspects and variants

The sealing wall 3 is in the form of a plate made of metallic material, preferably aluminum or stainless steel.

The thermal conduction of the sealing wall 3 is between 15 W / m.K and 230 W / m.K. More particularly, the thermal conduction of the sealing wall 3 is between 15 W / m.K and 50 W / m.K for a stainless steel plate, and between 120 W / m.K and 230 W / m.K for an aluminum plate.

Generally, the batteries 2 rest on the sealing wall 3 which forms the bottom wall of the battery compartment 11 (as illustrated in FIGS. 1 to 3), or else of the housing 10 (as illustrated in FIG. 4).

However, in a third embodiment of the invention, illustrated in FIG. 5, it is possible to implement the sealing wall 3 above the battery while maintaining direct contact between the battery 2 and the sealing wall 3. In this variant, the sealing wall 3 then forms the upper wall of the housing

10.

In a fourth embodiment, illustrated in FIG. 6, the sealing wall 3 forms one of the side walls of the housing 10, the battery 2 always being in direct contact with the sealing wall 3.

The battery 2 is formed by a plurality of electrical cells of the cylindrical, prismatic or pocket type (pouch cell in English), for example.

The two embodiments of the means for holding the conduits 41 to the sealing wall 3 (illustrated in FIGS. 2 and 3) can obviously be modified / adapted to suit each of the four embodiments of the invention (illustrated in Figures 1 and 4 to 6).

The use of a sealing wall 3 in order to delimit a battery compartment 11 and an exchanger compartment 12 makes it possible to facilitate the maintenance operations of the battery 2 and / or of the exchanger 4. In fact, when a intervention must be carried out on the battery 2, this does not require any operation / intervention on the exchanger 4, and vice versa.

Thus, there is no risk of deterioration of the exchanger 4 during an intervention on the battery 2, and vice versa. Since the battery 2 and the exchanger 4 are housed in different compartments 11, 12 separated by the sealing wall 3, they can be handled independently.

In addition, in the event of a maintenance operation on the exchanger 4, the battery 2 is protected from the risks of fluid leakage linked to this operation by the presence of the sealing wall 3.

Claims (11)

1. A thermal regulation device for at least one electrical energy storage element (2), comprising a heat exchanger (4) comprising: 5 · at least one conduit (41) for circulation of a heat transfer fluid; and • a sealing wall (3) disposed between said circulation duct (41) and said storage elements (2), the sealing wall (3) being thermally conductive. 2. A thermal regulation device according to claim 1, characterized in that 10 said sealing wall (3) is formed of metallic material, for example aluminum or stainless steel. 3. A thermal regulation device according to claims 1 and 2, characterized in that said sealing wall (3) has a thermal conduction between 15 W / m.K and 230 W / m.K. 15 4. A thermal regulation device according to one of claims 1 to 3, characterized in that said sealing wall (3) is a plate. 5. A thermal regulation device according to one of claims 1 to 4, characterized in that the surface of said sealing wall (3) located on the side of said electrical energy storage elements (2) follows the shape of these 20 items. 6. A thermal regulation device according to one of claims 1 to 5, characterized in that said exchanger (4) comprises two plates (412a, 412b) fixed together to delimit said conduit (41), the plates (412a, 412b) comprising a plurality of channels (414). 25 7. A thermal regulation device according to one of claims 1 to 5, characterized in that said exchanger (4) comprises a tube (415) delimiting the conduit (41), the tube (415) preferably delimiting a plurality of channels (417). 8. A thermal regulation device according to one of claims 1 to 7, characterized in that said electrical energy storage element (2) is a 30 electrical cell, for example of cylindrical, prismatic, or pocket type. 9. A thermal regulation device according to one of claims 1 to 8, characterized in that it comprises a housing (10) with a compartment (11) for housing the storage element (2) and a compartment (12 ) housing the exchanger (14), said sealing wall (3) separating the two compartments. 5 10. A thermal regulation device according to one of claims 1 to 9, characterized in that it comprises a housing (10) for housing the electric energy storage element (2), the sealing wall (3) being formed by a wall of the housing (10), the device further comprising a support wall (5) of the exchanger (4) fixed on the housing (10). 10 11. A thermal regulation device according to one of claims 1 to 10, characterized in that the fluid is a cooling fluid or a cooling liquid. 3054; 1/5