FR2962077A1 - COOLING A POWER BATTERY OF A DRIVE MOTOR OF A MOTOR VEHICLE. - Google Patents

Abstract

Battery charging device (2), characterized in that it comprises a battery tank (3) comprising a heat exchanger (4) for cooling the battery tank (3) delimited by at least one plate (10) delimiting a space (11) for circulating a first cooling fluid of the battery tray (3) and in that it comprises a water chamber (41) in which a second fluid circulates and in that it comprises a housing for the removable and sealed attachment of a battery tray (3) so that the second fluid cools the first fluid through the at least one plate (10).

Description

The present invention relates to a battery tray and a cooling device of a battery tray, particularly adapted for its positioning on a battery charger.

Some motor vehicles, such as electric or hybrid vehicles, include a battery for powering an electric drive motor. Such a battery heats up during use, both during the driving period of the motor vehicle and recharge period. This heating may induce premature aging of a battery. Thus, the solutions of the state of the art use cooling solutions of the battery.

The document US2008 / 0121380 for example describes the cooling of several battery packs arranged in a support by a circulation of air, this circulation being arranged with baffles to allow equivalent cooling of all the batteries, whatever their distance from the source of fresh air ventilation. The disadvantage of this solution stems from the fact that the cooling obtained remains generally mediocre.

On the other hand, it is interesting to exchange a battery when its energy level is low against a new charged battery. This can be done in a station similar to a service station in which one can fill a gas tank of a motor vehicle. Such a solution however makes more complex the cooling of the battery because the chosen solution must remain compatible with the removable nature of the battery, and allow a large number of battery mounting / dismounting operations.

The object of the invention is therefore to provide an improved solution for cooling a battery of a motor vehicle, which does not have all or some of the disadvantages mentioned above.

More specifically, the invention seeks to achieve the following objects:

A first object of the invention is to provide a battery cooling solution of a motor vehicle which involves a high-performance heat exchange, to obtain efficient cooling at lower cost.

A second object of the invention is to provide a battery cooling solution of a motor vehicle compatible with the removable nature of a battery. For this purpose, the invention is based on a battery charging device which comprises a water chamber in which a second fluid circulates and a housing for the removable attachment of a battery tray so that the second fluid cools a first fluid through the at least one plate. The battery container for a motor vehicle may comprise a heat exchanger for cooling the battery tray from a first fluid, characterized in that the heat exchanger is delimited by at least a first plate defining a circulation space. the first cooling fluid of the battery tray.

The space may be between a substantially flat wall of the surface of the battery tray and the at least one first plate which is flat or comprises at least one relief. The at least one first plate may form a succession of reliefs of trapezoidal or corrugated section.

The at least one first plate may comprise at least one relief of minimum height equal to 2 centimeters.

The at least one first plate may have a succession of reliefs forming elements independent of each other.

The at least one first plate may define independent channels in which the first fluid flows, these successive channels being connected by conduits connecting their ends.

The at least one first plate may be extended to a surface of the battery tray by one or more solid or perforated plates in its central portion.

The at least one first plate may comprise conductive fins extending towards the circulation space of the first fluid. The first fluid may be a coolant.

The at least one first plate may comprise at least one deformation zone to improve its interlocking with a corresponding plate.

The at least one first plate can be connected to the battery tray by at least one resilient means.

The invention also relates to a part of a cooling device for a motor vehicle battery container as described above, comprising a space for the circulation of a second fluid, characterized in that this space is delimited. by at least one second plate whose shape is adapted to fit the shape of the at least one first plate of the battery tray during their nesting. The space for the circulation of the second fluid may be between a substantially flat base and the at least one second plate which is flat or comprises at least one relief.

The at least one second plate may form a succession of reliefs of trapezoidal or corrugated section.

The at least one second plate may have a succession of reliefs forming elements independent of each other. The at least one second plate may delimit independent channels in which the second fluid flows, these channels being connected by conduits connecting their ends.

The at least one second plate may be extended to the substantially planar base by one or more solid or perforated plates in its central portion.

The at least one second plate may comprise conductive fins extending towards the circulation space of the second fluid.

The second fluid may be a coolant.

The at least one second plate may comprise at least one deformation zone to improve its interlocking with a corresponding plate. The at least one second plate can be connected to the substantially flat base by at least one resilient means.

The at least one second plate may delimit independent channels in which the second fluid flows, these channels being subjected to elastic means of independent springs type.

This part of a cooling device for a battery container for a motor vehicle may belong to a motor vehicle or to a battery charging device.

The invention also relates to a motor vehicle characterized in that it comprises a portion of a cooling device of a battery tray as described above.

The motor vehicle may comprise a removable battery tray as described above, so that the second fluid cools the first fluid through the at least two plates. The invention also relates to a battery charging device, characterized in that it comprises a part of a cooling device of a battery tray as described above.

These objects, features and advantages of the present invention will be set forth in detail in the following description of particular embodiments which are non-limiting in connection with the accompanying figures in which: Figure 1 is a schematic side view in section of a motor vehicle whose battery is removably connected to the vehicle and comprises a cooling device according to the invention.

2 shows a side view in section of a motor vehicle whose battery is removably connected to the vehicle and comprises a cooling device according to the invention.

Figure 3 shows an enlarged side sectional view of the battery cooling device according to the invention.

FIG. 4 represents a sectional side view of the battery cooling device according to the invention.

FIG. 5 represents a sectional side view of the battery cooling device according to the invention.

FIG. 6 schematically represents a view from above of the battery cooling device according to the invention. Figure 7 shows a side sectional view of the battery cooling device according to the invention.

Figure 8 shows a sectional side view of a cooling device according to the invention.

Fig. 9 is a sectional side view of a battery cooler on a battery charging station according to an embodiment of the invention. Fig. 10 is a sectional side view of a battery cooling device on a battery charging station according to a variant of the embodiment of the invention.

Figures 11a and 11b show two phases of an interlocking of a cooling device according to the invention.

Figure 12 shows the interlocking of a cooling device according to the invention. In the different figures, the same references will be used to designate the same components or equivalent components, in order to facilitate their understanding.

The concept of the invention is based on a cooling of the battery tray of a motor vehicle through at least one plate of a battery tray which cooperates with a cooling chamber, as will be detailed later.

Figures 1 and 2 show a motor vehicle 1 equipped with a battery tray 3, comprising a plurality of batteries 2, in a slightly dismantled configuration of the motor vehicle 1 to more easily view the battery cooling device which comprises a first part 4 belonging to the battery tray 3 and cooperating with a second part 5 fixed to the motor vehicle.

The first part 4 of the cooling device, visible in FIG. 3, comprises a first thin metal plate 10, which can extend over the entire upper surface of the battery tray 3 and of section 30 formed by a multitude of trapeziums, which delimits a closed and sealed single space 11 between the upper surface 6 of the battery tray 3 and the plate 10, forming a first channel for the circulation of a first direct cooling fluid of the battery tray 3. To improve the exchange between the plate 10 and the first fluid, the plate 10 has fins 14 extending towards the interior of the space 11 where the first fluid flows in order to improve the heat exchange between this fluid and the plate 10. This first part 4 of the cooling device is in fact a heat exchanger for cooling the battery tray 3 by circulating a fluid around at least one of its walls. Alternatively, this first fluid could travel around and / or inside the battery tray, to implement its cooling.

The second part 5 of the cooling device, fixed on the motor vehicle 1, comprises a second metal plate 20 of small thickness, trapezoidal section and dimensions intended to come in perfect theoretical interlock with the plate 10 of the battery tray, to ensure a optimal contact between the two plates, necessary for the optimization of the heat exchange through the two plates as will be detailed later. The two plates are thus movable relative to each other in a vertical direction V, to allow assembly and disassembly of the battery tray 3 of the motor vehicle 1, in a vertical direction. The plate 20 is connected to the motor vehicle in an elastic manner, by means of a flat base 22 fixed to the vehicle by one or more springs 23. This arrangement delimits a single closed and sealed space 21 between the flat base 22 and the plate 20 forming a second channel for the circulation of a second cooling fluid. In the configuration of fixing the battery pack 3 on the motor vehicle, the two plates 10, 20 are in contact and a heat exchange is established between the two cooling fluids. The second fluid of the space 21 cools the first fluid of the space 11 which directly cools the battery tray. As a remark, the plate 20 can be equipped with fins 24 extending towards the space 21 in a manner similar to the first plate 10.

According to an advantageous embodiment of the invention, the two plates 10, 20 have a corresponding non-planar shape, in relief, allowing their fitting as close as possible to form overall a large exchange surface, much greater than a solution similar which would use flat plates, as illustrated in Figure 8 when describing a third simplified embodiment of the invention.

The choice of trapezoid-shaped reliefs is advantageous in that this shape fulfills a self-centering function which facilitates the interlocking of the two exchangers and is well adapted to the uncertainty of positioning between the battery tray 3 and the vehicle. 1 during a phase of mounting the battery tray. FIGS. 11a and 11b illustrate for this purpose the respective approach of the two plates 10, 20. In a situation where the initial approach has a certain offset, represented by the distance d in FIG. 11a, the trapezoidal shape of the sections of the two plates will automatically bring them closer by removing this offset when their surfaces will come against each other, to arrive at the non-shifted diagram shown in Figure 11b.

On the other hand, to further improve the interlocking between the two plates, an elastic means acts on at least one of them. In the embodiment shown, an elastic means is disposed on the second part 5 fixed to the motor vehicle. Alternatively, an elastic means may be arranged on the first portion attached to the battery tray 2. This elastic means exerts a force that promotes the mutual approximation of the two plates and promotes their positioning to the nearest and then maintaining them in this position, thereby reducing the presence of insulating air between the two plates and thus increasing the performance of the heat exchange between the two fluids.

On the other hand, at least one of the plates may have a lower rigidity so that it can be deformed under the contact force with the second plate. Such a characteristic thus makes it possible, by deformation of at least one plate, to obtain improved contact between the two plates, to compensate for any play, and thus to avoid the presence of air between the two plates. Alternatively, any other solution allowing the deformation of at least one of the two plates achieves this advantageous effect. This deformation can be very slight, be in the form of a simple microdeformation to be sufficient to significantly increase the heat exchange through the two plates. FIG. 12 illustrates such a solution in which the two plates 10, 20 have imperfections, caused by the errors and dispersions of their manufacturing processes, which result in the presence of play zones 31 when they are brought together. In these play zones, the initial geometry of the plates 10, 20 does not allow their contact over their entire surface. However, deformation zones 30 are provided on these plates 10, 20, which will automatically deform under the pressure force during the approach of the plates so that the surfaces of the two plates 10, 20 will tend to take corresponding forms. allowing their contact over their entire surface.

FIG. 2 represents a second embodiment in which the two parts 4 ', 5' of the cooling device comprise two plates 10 ', 20' of undulating section, for example sinusoidal.

Alternatively, these two plates may have reliefs of any non-planar shape, which may be a succession of identical or different patterns, to obtain a satisfactory result. These different reliefs can belong to the same plate or to separate plates. As a remark, a relief can be obtained by the combination of several flat plates forming a set equivalent to a non-flat plate. Each relief is defined by a non-planar assembly, not parallel to the surface 6 of the battery tray which is generally flat. The shape of the two plates is naturally complementary to allow their interlocking when fixing the battery tray 2 in its housing. In addition, the plate or plates can form several reliefs: for example, one can choose between 6 to 12 reliefs whose dimensions are inscribed in a rectangle of 30 X 20 centimeters. Preferably, a relief has dimensions sufficient to significantly increase the exchange surface without, however, greatly increasing the size. A good compromise is to choose reliefs whose maximum distance from the battery tray is between 2 and 20 centimeters. In fact, the plate thus preferably comprises at least one relief of minimum height equal to 2 centimeters.

However, FIG. 8 illustrates a simplified third embodiment, in which the two plates 10 ", 20" are planar. This embodiment makes it possible to reduce the cost since it is much simpler: however, this simplification is done to the detriment of the performance of the heat exchange, which is less important than in the previous modes of execution since the surface exchange is reduced. It will be noted that the first fluid circulates within the space 11 "in a direction opposite to that of the second fluid in the space 21", as in the other embodiments. In all cases, the concept of juxtaposing two separate plates to obtain a heat exchange through these two plates makes it possible to implement a double flow heat exchange, by two fluids, which is particularly suitable for a disassembly situation. battery tray, while achieving a satisfactory heat exchange and therefore cooling. The plates will preferably be in a metal of good thermal conductivity such as a metal and of a thin thickness, for example less than 2 mm. In addition, these plates are positioned outside the battery tray and the motor vehicle, or in a peripheral part, or charger to make their assembly possible.

FIG. 4 illustrates a first embodiment variant of the first embodiment in which the bases of the various raised parts of the plates 10, 20, that is to say of the different trapezes, are respectively connected to the upper surface 6 of the battery tray and flat base 22 by pads 15, 25 to increase the rigidity of the plates 10, 20, especially in their central area. Such wafers 15, 25 separate the fluid circulation spaces 11, 21 into several zones 11a, 11b, 11c; 21a, 21b, 21c. These different areas can be completely independent using solid wafers or communicate using perforated wafers. In the variant illustrated in Figure 4, all the reliefs are separated by platelets. Naturally, another solution would be to use platelets to separate only part of the reliefs.

FIG. 5 illustrates a second variant embodiment in which the various channels 11a, 11b, 11c, 21a, 21b, 21c are obtained by six independent trapezoidal plates 10a, 10b, 10c, 20a, 20b, 20c, directly mounted on their respective bases. The fluids flow separately and at higher velocity in these channels, which increases the heat exchange coefficient across the plates.

Figure 6 illustrates from above the path of the first fluid in a case where the first part of the device 4 has seven channels 11a to 11g. Each channel is connected to the next channel on one of its ends by a conduit 17, which allows a continuous path of the fluid that travels back and forth in these channels between an inlet 16 and an outlet 18. A similar diagram in the opposite direction is organized for the second fluid.

FIG. 7 illustrates a third embodiment in which each channel 21a, 21b, 21c connected to the vehicle 1 is subjected to its own independent elastic effect by its own elastic means, such as springs 23a, 23b, 23c, respectively. For this, the channels 21a, 21b, 21c are independently formed by separate plates 20a, 20b, 20c, as in the previous variant, further mounted on separate flat bases 22a, 22b, 22c, connected to the vehicle. 1 by their springs 23a, 23b, 23c own. Such an embodiment allows a better adjustment and catching of the games between the different upper and lower channels and therefore increased contact between the different plates, and a reduction of the thermal resistance formed by their association.

The embodiments described above make it possible to form a battery cooling device by a double flow, a first flow being at the level of the battery tray and subject to heat exchange with a second flow arranged on the motor vehicle. Similarly, a second flow can be arranged at the housing receiving the battery tray in a charging station. Thus, in all the examples illustrated above, it is possible to obtain a battery charger solution by replacing the motor vehicle 1 with a charger.

In addition, the invention advantageously makes it possible to use liquids for the two fluids, which makes it possible to achieve a higher heat exchange performance than the use of gas. Naturally, it remains compatible with a use of gas, such as air, if desired.

The solution of the invention finally has the following advantages: it has a very good heat exchange due to the possibility of using coolants, which have a better performance than air; - It has a very good heat exchange due to the possibility of choosing a large heat exchange surface; - It is perfectly suited to vehicles with removable battery, including a vertical translation movement, since it is formed by two separate plates just in contact.

As a note, the battery tends to heat up more significantly during a charging phase, including a fast charge, than when driving a motor vehicle. For this reason, a battery charging station can be equipped with a battery cooling part which differs from the previous embodiments illustrated in the context of a motor vehicle, in order to obtain greater cooling. For this, a water chamber principle is implemented.

FIG. 9 represents a battery charging station with a water chamber according to a first embodiment. A battery tray 3 as described previously has been removed from a motor vehicle and is positioned in a housing provided in a charging station 40, which comprises a water chamber 41 in which is positioned the first part 4 of the device. cooling connected to the battery tray 3, and in particular its plate 10 or its plates 10a, 10b, 10c. A flow of water is organized transversely to the plates 10i, in the direction D, to cool the first fluid directly in contact with the battery tray 3. Seals 42 are arranged on each side of the battery tray to close the In such an embodiment, the heat exchange between the two fluids present respectively in spaces Ili and 41 is improved since the thermal resistance separating them no longer comprises a single plate 10i and is therefore Figure 10 illustrates a second embodiment in which the water chamber 41 is no longer above the battery tray but laterally. This embodiment avoids positioning the water above the battery tray 3 and represents a secure solution since the water does not come into direct contact with the surface of the battery tray, contrary to the previous embodiment: if the tank battery 3 has a leak, so water does not flow into the tank.

The solution shown in Figures 9 and 10 based on a water chamber can naturally work with any other fluid. In addition, it could also be implemented in a similar way on a motor vehicle, particularly in a case that would cause significant heating of the batteries.

The invention has been described from a battery tray 3 comprising several separate complementary batteries 2. Naturally, it applies regardless of the number of batteries, even for a single battery.

On the other hand, the invention is particularly suitable for a removable battery tray, allowing its disassembly of a motor vehicle for loading into a specific charging station. Naturally, it remains effective in the case of a non removable battery tray.

Claims (3)

CLAIMS: 1. Battery charging device (2), characterized in that it comprises a water chamber (41) in which a fluid circulates and in that it comprises a housing adapted for removable and leakproof attachment of a tank of batteries (3) so that the fluid cools a first fluid of the battery tray through at least one exchange plate (10). 2. Battery charging system (2), characterized in that it comprises a charging device according to the preceding claim and a battery tray (3) comprising a heat exchanger (4) for cooling the battery tray (3). ) delimited by at least one plate (10) delimiting a space (11) for circulating a first cooling fluid of the battery tray (3), the fluid of the water chamber being able to cool the first fluid through the at least one plate. 3. Battery charging system according to the preceding claim, characterized in that the water chamber is above the battery tray or on the side of the battery tray. 25