FR3104825A1 - Packaging device, assembly comprising the device, battery and vehicle comprising such an assembly - Google Patents

Abstract

Conditioning device, assembly comprising the device, battery and vehicle comprising such an assembly The conditioning device (15) comprises at least one conditioning circuit (21) having in series exactly three rectilinear coolant liquid circulation channels (27), juxtaposed in a transverse direction (T) and parallel to each other; - the or each conditioning circuit (21) having a developed length less than or equal to three times the length of the conditioning device (15); - the circulation channels (27) having, in the transverse direction (T), each having a determined average width, two neighboring circulation channels (27) having, in the transverse direction (T), a spacing less than the average width divided by two. Figure for abstract: 2

Description

Conditioning device, assembly comprising the device, battery and vehicle comprising such an assembly

The present invention generally relates to electricity storage batteries for vehicles.

The batteries used on board electric propulsion vehicles are typically of the lithium-ion (Li-ion) type. The thermal conditioning of these batteries is critical to their performance. In operation, electricity storage cells release significant amounts of heat. In the absence of an effective cooling system, significant thermal gradients can develop in the battery. This creates differences in internal resistance from one electricity storage cell to another, so that these electricity storage cells have variable electrical voltages at their terminals.

Such a situation is unfavorable for the performance and for the life of the battery. Vehicle performance may also be affected.

In order to maintain a uniform temperature distribution in the battery, and constant electrical voltages from one electricity storage cell to another, it is imperative to equip the battery with an effective conditioning device.

In this context, the invention aims to propose a conditioning device allowing satisfactory operation of the battery.

To this end, the invention relates to a conditioning device for a vehicle battery, the battery comprising at least one module having electricity storage cells juxtaposed in a direction of juxtaposition and electrically connected to each other, the module having a heat exchange surface, the conditioning device comprising:

- a heat transfer liquid supply manifold;

- a coolant liquid evacuation manifold;

- at least one conditioning circuit configured to exchange heat with the heat exchange surface, the or each conditioning circuit having a liquid inlet connected to the supply manifold, a liquid outlet connected to the evacuation manifold, and exactly three rectilinear heat transfer liquid circulation channels, juxtaposed in a transverse direction and parallel to each other, the three circulation channels being placed in series and fluidly connecting the liquid inlet to the liquid outlet;

- the or each conditioning circuit having, between the liquid inlet and the liquid outlet, a developed length less than or equal to three times the length of the conditioning device;

- The circulation channels each having, in the transverse direction, a determined average width, two neighboring circulation channels having, in the transverse direction, a spacing less than the average width divided by two . .

The design criteria adopted for the conditioning device make it possible to obtain very good results for the pressure drops of the heat transfer fluid circulating in the device, for the maximum temperature reached by the electricity storage cells in each module, for the homogeneity of the temperature distribution in each module, and for the overall heat transfer coefficient of the conditioning device.

This contributes to obtaining a uniform temperature and electrical voltage from one electricity storage cell to another, and therefore to the proper functioning of the battery.

The circuit length criterion makes it possible to limit the pressure drop.

The criterion of number of channels per circuit contributes to obtaining homogeneous heat transfer coefficients and situated in satisfactory ranges.

The spacing criterion between the channels contributes to obtaining a uniform temperature, in particular when the direction of juxtaposition of the electricity storage cells is substantially parallel to the transverse direction. In this case, the electricity storage cells are indeed typically parallel to the channels.

The conditioning device may also have the characteristics below:

- the average width of each circulation channel is between 10 and 100 mm, each circulation channel having an average height between 1 and 20 mm;

- the or each conditioning circuit has, between the liquid inlet and the liquid outlet, a developed length less than or equal to 6 m, and preferably less than or equal to 5 m, even more preferably less than or equal to 4 m .

According to a second aspect, the invention relates to an assembly comprising at least one module having electricity storage cells juxtaposed in the direction of juxtaposition and electrically connected to each other, the module having a heat exchange surface and a conditioning device having the above characteristics.

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

- the or each module has transversely a transverse width of between 80 and 1500 mm and has a length of between 80 and 2000 mm in a longitudinal direction perpendicular to the transverse direction ;

the conditioning device comprises, for the or each module, between one and five conditioning circuits, the circulation channels of the conditioning circuit(s) all being parallel to the same direction ;

- the electricity storage cells are prismatic, the direction of juxtaposition being substantially perpendicular to the transverse direction ;

- the electricity storage cells are pockets, the juxtaposition direction being substantially parallel to the transverse direction;

- the evacuation collector is in a heat exchange situation with the heat exchange surface, the conditioning device comprising a conditioning circuit whose circulation channels have an average width of between 10 and 100 mm, and a circuit additional conditioning whose circulation channels have an average width less than the average width of the circulation channels of the conditioning circuit.

According to a third aspect, the invention relates to a vehicle electricity storage battery, comprising an assembly having the above characteristics.

According to a fourth aspect, the invention relates to a vehicle comprising an electricity storage battery having the above characteristics.

Other characteristics and advantages 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:

- Figure 1 is a simplified schematic representation of a battery according to the invention;

- Figure 2 is a simplified schematic representation of the battery conditioning device of Figure 1;

- FIG. 3 is a graphic representation of the temperature distribution on the surface of the conditioning circuit in contact with the electricity storage cells of the modules obtained with the conditioning device of FIG. 2, for electricity storage cells prismatic perpendicular to the direction of fluid flow;

- FIG. 4 is a graphic representation of the temperature distribution on the surface of the conditioning circuit in contact with the electricity storage cells of the modules obtained with the conditioning device of FIG. 2, for electricity storage cells pocket-like parallel to the direction of fluid flow; And

- [Fig 6] [Fig 7] Figures 5, 6 and 7 show the heat exchange coefficients along the channels of the cooling circuits, for a module cooled respectively by a device according to the invention with two cooling circuits three channels each, by a device not in accordance with the invention with three conditioning circuits of two channels each, and by a device not in accordance with the invention with six conditioning circuits each having one circulation channel.

The battery 1 shown schematically in FIG. 1 is intended to equip a vehicle, typically a motor vehicle such as a car, a truck, a bus, a two-wheeler, etc.

This vehicle is typically a vehicle exclusively propelled by an electric motor, powered by the battery 1. Alternatively, the vehicle is of the hybrid type and is equipped with a thermal propulsion engine and an electric propulsion motor powered by the battery 1 .

As a variant, the vehicle comprises only one heat engine, the battery 1 supplying various equipment of the vehicle such as the lights, the interior lighting, the starter, etc.

As seen in Figures 1 to 3, the battery 1 comprises at least one module 3 having electricity storage cells 5 juxtaposed in a direction of juxtaposition and electrically connected to each other.

Battery 1 typically comprises several modules 3, only one being shown in Figure 1.

The module(s) 3 are placed in a sealed envelope, not shown.

The electricity storage cells 5 of the same module 3 are typically rigidly fixed to each other by any suitable means, for example by straps.

Each module 3 has a positive terminal and a negative terminal. The electricity storage cells 5 each have two electrical terminals, via which the electricity storage cells 5 of the same module 3 are electrically connected to each other, in series and/or in parallel. The electricity storage cells 5 of the same module 3 are also electrically connected to the negative and positive terminals of the module 3.

Each electricity storage cell 5 has two large faces 7, 9 opposite to each other, and a peripheral edge 11 connecting large faces 7, 9 opposite to each other.

The electricity storage cells 5 are typically pressed against each other by their respective large faces 7, 9.

The or each module 3 has a heat exchange surface 13.

Typically, this heat exchange surface 13 is defined by portions of slices 11 of electricity storage cells 5 of module 3, juxtaposed to each other in the direction of juxtaposition. The heat exchange surface 13 is preferably flat. It is typically turned towards the running surface of the vehicle.

Battery 1 further comprises a conditioning device 15.

The conditioning device 15 is provided to cool the electricity storage cells 5 of the or each module 3. Preferably, it is also provided to heat the electricity storage cells 5 of the or each module 3.

The conditioning device 15 comprises:

- a supply manifold 17 with a heat transfer liquid;

- an evacuation manifold 19 for the heat transfer liquid;

- at least one conditioning circuit 21 configured to exchange heat with the heat exchange surface 13.

The heat transfer liquid is of any suitable type. For example, it is the engine coolant, or another liquid coming from a circuit completely separate from the engine cooling circuit.

The supply manifold 17 is fluidically connected in any event to an external circuit comprising a circulation device, not shown, such as a pump. The supply manifold 17 is fluidically connected to the discharge of the circulation device.

The evacuation manifold 19 is fluidically connected to said external circuit, on the suction side of the circulation member.

A cold source is interposed on the external circuit, to evacuate the thermal energy released by the battery 1. If necessary, a hot source is interposed on the external circuit.

The or each conditioning circuit 21 has a liquid inlet 23 connected to the supply manifold 17, a liquid outlet 25 connected to the discharge manifold 19, and exactly three channels 27 for the circulation of the coolant liquid (FIG. 2).

The circulation channels 27 are straight, juxtaposed in a transverse direction T and parallel to each other. They extend substantially in a longitudinal direction L perpendicular to the transverse direction T.

The three circulation channels 27 are placed in series and fluidically connect the liquid inlet 23 to the liquid outlet 25.

The three circulation channels 27 have substantially the same length. Their respective longitudinal ends are connected to each other by two elbows 29. The elbows 29 are U-shaped, and are placed at the two opposite longitudinal ends of the central circulation channel. They are curved in opposite directions to each other.

Each conditioning circuit 21 therefore draws the shape of an S.

Each conditioning circuit 21 is substantially inscribed in a longitudinal and transverse plane, parallel to the heat exchange surface 13. It is placed in contact with or close to the heat exchange surface 13.

The conditioning circuit 21 is in thermal contact with the heat exchange surface 13, directly or through a plate. The plate is then made of a material guaranteeing good heat exchange between the conditioning circuit 21 and the heat exchange surface 13.

Advantageously, the or each conditioning circuit 21 has between the liquid inlet 23 and the liquid outlet 25 a developed length less than three times the length of the conditioning device 15.

The length of the conditioning device is typically taken along the longitudinal direction L. It corresponds to the total longitudinal size of the device 15, including the collectors 17 and 19 and the conditioning circuit 21. In the example represented in FIG. , this longitudinal length runs from the upper edge of the supply manifold 17 to the lower edge of the exhaust manifold 19.

Alternatively, the developed length of the or each conditioning circuit 21 is less than or equal to the width of the device 15.

Typically, the developed length of the or each conditioning circuit 21 is less than or equal to 6 m, and preferably less than or equal to 5 m, even more preferably less than or equal to 4 m.

The circulation channels 27 each have, in the transverse direction T, a determined average width, two neighboring circulation channels 27 having, in the transverse direction T, a spacing less than the average width divided by two.

The average width corresponds to the width of the circulation channel 27 averaged over the entire longitudinal length of the circulation channel 27.

The circulation channels 27 of the same conditioning circuit 21 typically have the same average width.

Spacing is taken in the transverse direction. It corresponds to the distance between the external surfaces of the two circulation channels. Here we consider the spacing between the external surfaces, averaged over the entire longitudinal length of the rectilinear portions facing the two circulation channels 27.

The average width of each circulation channel 27 is between 10 and 100 mm, preferably between 15 and 60 mm, and even more preferably between 20 and 45 mm.

Furthermore, each circulation channel 27 has an average height of between 1 and 20 mm, preferably between 1.5 and 10 mm, and even more preferably between 2 and 4 mm. The height is taken in a direction perpendicular to the longitudinal and transverse directions. The average height corresponds to the height of the circulation channel 27 averaged over the entire longitudinal length of the circulation channel 27.

The invention is particularly well suited when the or each module 3 has, in the longitudinal direction L, a length of between 80 and 2000 mm, preferably between 120 and 1000 mm and even more preferably between 150 and 800 mm and has a transverse width between 80 and 1500 mm, preferably between 120 and 800 mm, and even more preferably between 150-600 mm.

Typically, the module 3 has substantially the same longitudinal length and the same transverse width as the heat exchange surface 13.

The conditioning device 15 preferably comprises, for the or each module 3, between 1 and 5 conditioning circuits 21, the circulation channels 27 of the conditioning circuit(s) 21 all being parallel to the same direction.

This direction is the longitudinal direction L.

The conditioning circuits 21 are juxtaposed transversely.

Each circulation channel 27 extends longitudinally over at least 75% of the length of the corresponding heat exchange surface 13.

Two circulation channels 27 neighboring transversely and belonging to two different conditioning circuits 21 have transversely a spacing less than the average width of the circulation channels 27 divided by two.

The two neighboring circulation channels 27 typically have the same average width.

When the battery 1 comprises several modules 3, as illustrated in FIG. 2, the modules 3 are advantageously juxtaposed transversely. They are arranged in the same orientation, the directions of juxtaposition of the electricity storage cells being parallel to each other.

In the example of Figure 2, the battery 1 comprises four modules 3 juxtaposed transversely.

The heat exchange surfaces 13 are also juxtaposed transversely, substantially in the same plane. They typically all have substantially the same length and the same width.

The circulation channels 27 of the conditioning circuit(s) 21 of the various modules 3 are all parallel to the same direction. This direction is the longitudinal direction L.

The circulation channels 27 are all juxtaposed transversely.

Two circulation channels 27, adjacent transversely and belonging to two conditioning circuits 21 serving different modules 3, have a transverse spacing less than the average width of the circulation channels 27 divided by two.

The two neighboring circulation channels 27 typically have the same average width.

Alternatively, a conditioning circuit 21 may straddle the heat exchange surfaces 13 of two neighboring modules 3.

In the embodiment of Figure 3, the electricity storage cells 5 are prismatic. Their two large opposite faces 7, 9 are then substantially perpendicular to the longitudinal direction L. The direction of juxtaposition is substantially perpendicular to the transverse direction T.

Each electricity storage cell 5 extends over substantially the entire transverse width of the module 3.

Figure 3 shows the temperature distribution on the surface of the conditioning circuit in contact with the modules' electricity storage cells obtained with the conditioning device of Figure 2, for prismatic electricity storage cells. Seven zones have been delimited in this figure and referenced from a to g, a corresponding to the minimum temperature and g to the maximum temperature. Zone a has a lower temperature limit of 49.8°C. Zone g has an upper temperature limit of 54.5°C. The maximum temperature difference is therefore contained below 5°C, which is a common requirement of car manufacturers.

In the embodiment of Figure 4, the electricity storage cells 5 are pockets. Their two large opposite faces 7, 9 are then substantially perpendicular to the transverse direction T. The direction of juxtaposition is substantially parallel to the transverse direction T.

Each electricity storage cell 5 extends over substantially the entire longitudinal length of the module 3.

Figure 4 shows the temperature distribution on the surface of the conditioning circuit in contact with the electricity storage cells of the modules obtained with the conditioning device of Figure 2, for pocket electricity storage cells. Seven zones have been delimited in this figure and referenced from a to g, a corresponding to the minimum temperature and g to the maximum temperature. Zone a has a lower temperature limit of 50.4°C. Zone g has an upper temperature limit of 55.0°C. Again, the maximum temperature difference is kept below 5°C.

Figures 5, 6 and 7 graphically represent the heat exchange coefficients along the circulation channels of the cooling circuits, for a module cooled respectively by a device according to the invention with two conditioning circuits of three circulation channels each , by a device not in accordance with the invention with three conditioning circuits of two circulation channels each, and by a device not in accordance with the invention with six conditioning circuits each having one circulation channel.

These exchange coefficients are expressed in W/m².K.

Each figure comprises seven curves, referenced from 1 to 7. Curves 1 to 6 correspond to the evolution of the exchange coefficient along the six circulation channels 27 of the conditioning circuits 21. Curve 7 corresponds to the average of the curves 1 to 6.

Each circulation channel 27 is divided longitudinally into ten sections. Each point of the corresponding curve represents the average heat exchange coefficient on one of the sections of said circulation channel.

Figures 5, 6 and 7 have been established by calculation, considering the same assumptions (size of the heat exchange surface, characteristics of the module including heat release, section of the circulation channels, transverse spacing of the circulation channels, total heat transfer fluid flow, etc.).

It is apparent from these three figures that the conditioning device of the invention makes it possible to obtain the best performance (figure 5).

The exchange coefficients of the different circulation channels are very close to each other over most of the longitudinal length of the circulation channels. These coefficients diverge slightly at the ends of the circulation channels, but not excessively. Moreover, for the same circulation channel, the exchange coefficient remains relatively constant along the circulation channel, at a high value (between 1300 and 1500 W/m².K over the greater part of the length of the circulation channel). traffic). These different aspects make it possible to guarantee efficient heat removal over the entire heat exchange surface 13, and therefore a uniform and moderate temperature for all the electricity storage cells 5.

This is not at all the case for the three-circuit conditioning device of two circulation channels (Figure 6). The heat exchange coefficients are very different from one circulation channel to another. The differences are very significant at the ends of the circulation channels. For some circulation channels, the exchange coefficient varies significantly along the circulation channel.

For the conditioning device with six circuits of one circulation channel each (figure 7), the exchange coefficients vary in a strictly identical manner along the different circulation channels. On the other hand, they are much lower than for the device of the invention (between 900 and 1000 W/m².K over most of the length of the circulation channels).

According to another aspect of the invention, visible in Figure 2, the exhaust manifold 19 is in a heat exchange situation with the heat exchange surface 13. This is the case in particular for the module 3 located the more to the left of figure 2.

More precisely, the exhaust manifold 19 is in a heat exchange situation with the heat exchange surface 13 over a relatively greater length for the module 3 located furthest to the left in FIG. heat exchange with the heat exchange surface 13 over a relatively shorter length for the other modules 3.

The conditioning device 15 associated with the module 3 on the left then advantageously comprises a conditioning circuit 21 whose circulation channels 27 have an average width of between 10 and 100 mm, and an additional conditioning circuit 31 whose circulation channels 27 have an average width comprised less than the average width of the circulation channels 27 of the conditioning circuit 21.

The additional conditioning circuit 31 is for the rest identical to the other conditioning circuits 21.

Such an arrangement makes it possible to thermally balance the evacuation of heat between the different modules 3.

Claims (11)

Conditioning device (15) for a vehicle battery, the battery (1) comprising at least one module (3) having electricity storage cells (5) juxtaposed in a direction of juxtaposition and electrically connected to each other, the module (3) having a heat exchange surface (13), the conditioning device (15) comprising:
- a manifold (17) for supplying a heat transfer liquid;
- a manifold (19) for discharging the heat transfer liquid;
- at least one conditioning circuit (21) configured to exchange heat with the heat exchange surface (13), the or each conditioning circuit (21) having a liquid inlet (23) connected to the supply manifold ( 17), a liquid outlet (25) connected to the evacuation manifold (19), and exactly three rectilinear heat transfer liquid circulation channels (27), juxtaposed in a transverse direction (T) and parallel to each other, the three channels circulation (27) being placed in series and fluidly connecting the liquid inlet (23) to the liquid outlet (25);
- the or each conditioning circuit (21) having, between the liquid inlet (23) and the liquid outlet (25), a developed length less than or equal to three times the length of the conditioning device (15);
- the circulation channels (27) having, in the transverse direction (T), each having a determined average width, two neighboring circulation channels (27) having, in the transverse direction (T), a spacing less than the average width divided by two. Packaging device according to Claim 1, in which the average width of each circulation channel (27) is between 10 and 100 mm, each circulation channel (27) having an average height between 1 and 20 mm. Conditioning device according to Claim 1 or 2, in which the or each conditioning circuit (21) having, between the liquid inlet (23) and the liquid outlet (25), a developed length less than or equal to 6 m , and preferably less than or equal to 5 m, even more preferably less than or equal to 4 m. Assembly comprising at least one module (3) having juxtaposed electricity storage cells (5) in the direction of juxtaposition and electrically connected to each other, the module (3) having a heat exchange surface (13) and a conditioning device (15) according to any one of claims 1 to 3. Assembly according to claim 4, in which the or each module (3) presents transversely a transverse width of between 80 and 1500 mm and presents a length of between 80 and 2000 mm in a longitudinal direction (L) perpendicular to the transverse direction (T ). Assembly according to Claim 4 or 5, in which the conditioning device (15) comprises, for the or each module (3), between one and five conditioning circuits (21), the circulation channels (27) of the circuit or circuits packaging (21) all being parallel to the same direction. Assembly according to any one of Claims 4 to 6, in which the electricity storage cells (5) are prismatic, the direction of juxtaposition being substantially perpendicular to the transverse direction (T). Assembly according to any one of Claims 4 to 6, in which the electricity storage cells (5) are pockets, the direction of juxtaposition being substantially parallel to the transverse direction (T). Assembly according to any one of Claims 4 to 8, in which the evacuation collector (19) is in a heat exchange situation with the heat exchange surface (13), the conditioning device (15) comprising a conditioning circuit (21) whose circulation channels (27) have an average width of between 10 and 100 mm, and an additional conditioning circuit (31) whose circulation channels (27) have an average width less than the average width circulation channels (27) of the conditioning circuit (21). Vehicle electricity storage battery (1), comprising an assembly according to any one of claims 4 to 9. Vehicle comprising an electricity storage battery (1) according to claim 10.