FR3052300A1 - COOLING DEVICE FOR A BATTERY OF A VEHICLE - Google Patents

Abstract

The present invention relates to a cooling device 1 of at least one battery of a vehicle comprising a first water cooling circuit for cooling the battery, a second water cooling circuit for cooling at least one other element of the vehicle, a radiator, and a refrigeration device. In a first mode of operation the first cooling circuit for cooling the battery comprises the radiator. In a second mode of operation the refrigeration device cools the water of the first cooling circuit to cool the battery, and the second cooling circuit for cooling at least one other element of the vehicle comprises the radiator.

Description

FIELD OF THE INVENTION The invention relates to the cooling by water of one or more batteries of a vehicle, in particular an electric or hybrid vehicle, using a battery fuel. 2. Prior Art

The electric motors of all-electric or hybrid vehicles are powered by batteries to be effectively cooled. It is indeed important to maintain such a battery below a certain threshold, as this makes it possible to protect it and prolong its life, and / or to guarantee satisfactory performance.

In the remainder of the disclosure, the word "battery" will be used indifferently to designate a battery of an electric or hybrid vehicle

Different technologies are used to cool the batteries: air cooling, according to which fresh air, possibly freshened or extracted from the cabin of the vehicle is projected on the battery to cool it; direct cooling cooling, wherein the vehicle air conditioning system is used to directly cool the battery disposed on a tray within which the coolant circulates; water cooling, wherein a cooling loop comprising a pump and a radiator is used to cool the battery. This system is limited by the ambient temperature. The invention relates to a cooling device by water, and more generally by heat transfer liquid.

In the remainder of the disclosure, any heat-carrying liquid, usually a mixture of water and antifreeze, is called water; and system or device for cooling with or by water respectively any device or cooling system using such a heat transfer liquid.

When the ambient temperature becomes too high, it is no longer possible to have enough cold water to cool the battery (s) to an acceptable temperature. An existing solution is then to use a refrigerant system, for example that used for the air conditioning of the vehicle, to cool the water of the cooling device, as proposed in WO2011083976.

When the refrigerant system is used, it often becomes more efficient to isolate the radiator from the water cooling circuit. This is particularly the case when the ambient temperature is higher than the temperature of the water in the cooling system. The radiator is no longer used. The invention aims to provide an optimized cooling device. 3. Summary of the invention

In order to achieve all or part of the objectives the invention proposes a device for cooling at least one battery of a vehicle, comprising means for selecting between at least two cooling modes of said battery.

In a first cooling mode, the battery is connected to a first cooling circuit (Cl), comprising at least a first radiator for cooling the battery; and in a second cooling mode the battery is connected to a second cooling circuit (C2) comprising a refrigeration device.

The selection means ensure, in said second cooling mode, a connection of the first radiator to at least one other element of the vehicle requiring cooling.

Thus, the selection means not only ensure that the cooling mode of the battery is the most suitable for the conditions, but also that the first radiator is always used to cool at least one element of the vehicle: the battery in the first operating mode and in the second mode of operation at least one other element requiring cooling. The cooling capacities of the first radiator are therefore used in all modes of operation.

In a particular embodiment according to the invention, the first radiator cools in addition to the battery also at least one other element of the vehicle in the first cooling mode; this other element being always cooled by the first radiator in the second mode of operation.

Thus, in the various operating modes, the number of elements to be cooled is adapted to the cooling capacity of the first radiator, which makes it possible to use this cooling capacity used optimally.

Optionally, the device according to this embodiment may comprise a pump dedicated to the circulation of a coolant cooled by said first radiator in the second cooling mode.

Thus a good circulation of the coolant is ensured in the various modes, allowing to use effectively the cooling capacity of the first radiator.

According to one embodiment of the invention, in the second cooling mode the first radiator is connected to a third cooling circuit (C3) comprising at least a second radiator. The first radiator and the second radiator can be connected in series, or in parallel.

Thus, the cooling capabilities of the first radiator are always used where they are most effective, being associated with the capabilities of another radiator.

In one embodiment of the invention, the first radiator is mounted in a vehicle front face module in front of at least a second radiator, so as to facilitate heat exchange.

In one embodiment of the invention, the selection means control valves (VI, V2, V3, V4) for changing the circulation of the cooling liquid according to the cooling modes. Alternatively, the selection means are part of thermostats (VI, V2, V3, V4) for changing the circulation of the cooling liquid according to the cooling modes.

Thus, in the various cooling modes, the coolant circulates in the different cooling circuits, so as to best use the cooling capacity of the first radiator.

According to the invention, the other elements of the vehicle cooled by the first radiator in the second cooling mode belong to the group comprising: electric motors; condensers; electronic modules; transmission oil; the air of supercharging.

In one embodiment of the invention, the cooling device comprises a main condenser and an additional condenser, the additional condenser being cooled by the first radiator at least in the second cooling mode. Thus the cooling capacities of the first radiator are used where they are most effective. The invention also relates to a method of cooling at least one battery of a vehicle, comprising a step of selecting between at least two cooling modes of said battery: a first cooling mode in which said battery is connected to a first cooling circuit, comprising at least a first radiator for cooling said battery; and a second cooling mode in which said battery is connected to a second cooling circuit comprising a refrigeration device,

According to the invention, the selection step ensures, in the second cooling mode, a connection of the first radiator to at least one other element of the vehicle requiring cooling.

Thus the method according to the invention ensures that the cooling capacity of the first radiator is used efficiently in all modes of operation, to adapt to the operating conditions and the cooling needs of the battery and the various elements of the vehicle. 4. Figures Other features and advantages will appear more clearly on reading the following description of a particular embodiment of the disclosure, given as a simple illustrative and nonlimiting example, and the accompanying drawings, among which:

Fig. 1 and FIG. 2 schematically show a cooling device according to the invention;

Fig. 3 and FIG. 4 schematically show a second embodiment of the invention;

Fig. 5 and 6 schematically show a variant of the second embodiment of the invention. 5. Particular embodiments The invention therefore proposes to optimize the use of the cooling means, according to the different cooling modes used for the battery or batteries. In particular, there are at least two cooling modes of the battery: a first cooling mode in which a first cooling circuit implementing a first radiator is implemented; a second cooling mode, selected when the temperature is too high and the first cooling circuit with radiator is no longer effective, and implementing refrigeration means.

Thus, if it is necessary to maintain the temperature of the liquid at the battery for example at 25 °, it is possible to cool with a radiator for example as long as the ambient air is at a temperature below 20 °. Then another means must be implemented.

According to the invention, the first circuit, and therefore the first radiator, which has been disconnected from the battery, is connected to a third cooling circuit associated with one or more other elements that also need to be cooled. Thus, instead of being completely disconnected, and therefore unnecessary, the first radiator is reused for another function. This is all the more important as the second cooling mode is activated when the temperatures are high. It is therefore useful, especially in this situation, to exploit the cooling capabilities of the first radiator.

This other function can for example be the cooling, or the additional cooling, of at least one of the following elements: electric motors; condensers; electronic modules; transmission oil; the air of supercharging

Thus, the selection means that ensure the passage of the first cooling mode to the second cooling mode, for example as a function of a temperature threshold in the first cooling circuit or in the battery (and respectively for the passage of the second to first mode), simultaneously provide connection (and respectively disconnection) to this third circuit.

The third circuit may in particular be a cooling circuit associated with a second radiator, conventionally placed behind the first radiator in a front vehicle module. This approach is illustrated by the embodiment of Figs. 1 and FIG. 2, which schematically show a cooling device of at least one battery of a vehicle according to the invention, comprising a first water cooling circuit for cooling the battery, a second water cooling circuit for cooling at minus another vehicle element, a radiator, and a refrigeration device.

In the first cooling mode illustrated in FIG. 1 corresponding to a low ambient temperature, the first water cooling circuit Cl comprises the first radiator 11 which is sufficient to maintain the battery 12 at an acceptable temperature, less than a predetermined threshold.

In this first mode of operation, the third cooling circuit C3, connected to a second radiator 13, conventionally makes it possible to cool at least one other element of the vehicle, for example an electric motor 14 and water main and additional condensers 15 In this embodiment, these three elements are connected in parallel.

A first pump 17 circulates the water cooled by the radiator 11 in the first circuit C1, and a second pump 19 circulates the water cooled by the radiator 13 in the third circuit C3.

The refrigeration device 18 ("chiller" in English), mounted on a second circuit C2, is not connected to the battery 12, in this first cooling mode.

Valve sets VI, V2 and V3 configure these circuits C1 and C2, under the control of selection means (not shown), depending on the temperature at the battery 12 (and / or ambient temperature and the case other data). When this temperature reaches a predetermined threshold, from which the cooling via the first radiator 11 is no longer sufficient, these selection means act on the valve sets VI to V3, to pass in the second cooling mode shown in FIG. 2.

Since the ambient temperature is too high for the radiator alone to be sufficient to maintain the battery at an acceptable temperature, the refrigeration device 18 is thus used to cool the water of the first cooling circuit, which makes it possible to maintain the battery at a temperature acceptable. Thus, via the valve V3 and the pump 17, a second circuit C2 is created for cooling the battery 12, implementing the cooling device 18. The first radiator 11 is thus no longer connected to the battery 12.

In this second mode of operation, the first radiator 11 is then connected to the third cooling circuit C3 via the valves VI and V2, and participates in the cooling of the other elements 14, 15 and / or 16.

Thus, the first radiator 11 is no longer part of the first cooling circuit Cl, but it is not unused so far. It is mounted in series with the second radiator 13. It represents a significant refrigerant power that helps cool at least one other element of the vehicle whose operating temperature remains above ambient temperature.

The valve VI connects the inlet of the first radiator 11 to the outlet of the second radiator 13, downstream of the pump 19. The valve V2 connects the inlet of the additional condenser 16 to the outlet of the first radiator 11.

The second radiator 13 lowers the temperature of a first level, for example to about 50 °, then the first radiator 11 further cools the liquid.

Thus the cooling device according to the invention is more effective than the devices according to the prior art, through a better use of all the resources for cooling the various elements of the vehicle.

In an alternative embodiment VI, V2 and V3 are thermostats integrating the selection means, thus allowing the device to change operating mode without requiring a specific temperature measurement.

A second embodiment is shown in FIG. 3 and FIG. 4. In the first operating mode shown in FIG. 3, the first cooling circuit Cl for cooling the battery 12 also allows to cool another element 16 of the vehicle, in this case an additional condenser 16 connected in series with the battery. Thus, in the first mode of operation, when the ambient temperature is sufficiently low, the first radiator 11 is used in the first cooling circuit to cool several elements of the vehicle including the battery.

The third circuit C3 ensures, by means of the second radiator 13, the cooling of the electric motor 14 and the main condenser 15.

In the second mode of operation shown in FIG. 4, when the ambient temperature is too high for the first mode of operation to maintain the battery 12 at an acceptable temperature, the cooling of the battery 12 is provided by the refrigeration device 18, the valve V3 defining a new cooling circuit C2 for this battery.

The first cooling circuit C1 is disconnected from the battery 11, via the valve V2, but remains connected to the additional condenser 16, an additional pump 20 ensuring the circulation of the coolant. The second circuit C2 remains unchanged.

In an alternative embodiment V2 and V3 are thermostats integrating the selection means, thus allowing the device to change operating mode without requiring a specific temperature measurement.

Fig. 5 and 6 show a slightly different version of this second embodiment, operating in a similar manner but without the need for additional pump 20, thanks to the presence of additional valves V4 for changing the cooling circuit configurations when the device changes cooling mode , the two radiators 11 and 13 being in series in the second cooling mode.

In an alternative embodiment VI, V3 and V4 are thermostats integrating the selection means, thus allowing the device to change operating mode without requiring a specific temperature measurement.

According to other arrangements, the two radiators 11 and 13 can be assembled in parallel, in this second cooling mode.

In view of these three examples of implementation of the invention, it is obvious to the person skilled in the art that many configurations can be imagined for the different cooling loops, making best use of the resources available to cool the elements. of the vehicle, of which of course the battery or batteries.

Also, in another embodiment, the device may operate in a third combined mode, in which the refrigeration device and the first radiator are combined, in series or in parallel.

Thus for a device according to this embodiment, the radiator 11 will be sufficient to maintain the battery 12 at an acceptable temperature when the ambient temperature will be sufficiently low, in a first mode of operation. In a second mode of operation, the radiator 11 will be included in the second cooling circuit, in particular when the ambient temperature will be higher than the temperature of the desired water in the first cooling circuit.

And the device may optionally use the third mode of operation when the ambient temperature is too high for the radiator 11 is sufficient to maintain the battery 12 alone at an acceptable temperature, while remaining below the temperature of the desired water in the first circuit cooling. The invention also relates to a method of cooling at least one battery of a vehicle comprising a radiator, a refrigeration device, and other elements to be cooled.

Such a method comprises a measurement step, direct or indirect, of at least one temperature (ambient temperature, battery temperature, temperature in the circuit C1 and / or C2), and a selection step, depending on the or measured temperatures, a first or a second cooling step, respectively corresponding to the first and second cooling mode. The second cooling step includes connecting the first radiator to at least one other element than the battery.

The battery is cooled by means of a first water circuit including the radiator when the radiator is sufficient to maintain the battery at an acceptable temperature; otherwise the battery is cooled by means of a first circuit whose water is refrigerated and at least one other element of the vehicle is cooled by a second water circuit comprising the radiator.

The temperature measurement is direct when it is done by sensors and used by means of external selections controlling externally actuated valves (electrical or hydraulic), and indirect when thermostats are used. The invention also relates to a vehicle, in particular an electric or hybrid vehicle using a fuel cell, comprising a cooling device according to the invention, and / or of which at least one battery is cooled according to the method of the invention.

Claims (12)

A device for cooling at least one battery (12) of a vehicle, comprising means for selecting between at least two cooling modes of said battery: a first cooling mode in which said battery (12) is connected to a first cooling circuit (C1) comprising at least a first radiator (11) for cooling said battery (12); and a second cooling mode in which said battery (12) is connected to a second cooling circuit (C2) comprising a refrigeration device (18), characterized in that said selection means ensure, in said second cooling mode, a connection of said first radiator (11) to at least one other element (16) of said vehicle requiring cooling. Cooling device for at least one battery of a vehicle according to claim 1, characterized in that in the first cooling mode the first radiator (11) also cools at least one other element (16) of the vehicle, said at least one other element (16) being always cooled by the first radiator (11) in the second mode of operation. 3. Device for cooling at least one battery (12) of a vehicle according to claim 2, characterized in that it comprises a pump (20) dedicated to the circulation of a coolant cooled by said first radiator (11), in the second cooling mode. Cooling device for at least one battery (12) of a vehicle according to claim 1, characterized in that in the second cooling mode said first radiator (11) is connected to a third cooling circuit (C3). comprising at least a second radiator (13). 5. Device for cooling at least one battery (12) of a vehicle according to claim 4, characterized in that in the second cooling mode said first radiator (11) and said second radiator (13) are connected in series. . 6. Device for cooling at least one battery (12) of a vehicle according to claim 4, characterized in that in the second cooling mode said first radiator (11) and said second radiator are connected in parallel (13). . 7. Device for cooling at least one battery (12) of a vehicle according to any one of claims 1 to 6, characterized in that said first radiator (11) is mounted in a vehicle front face module, in front of at least a second radiator (13). 8. Device for cooling at least one battery (12) of a vehicle according to any one of claims 1 to 7, characterized in that said selection means drive valves (VI, V2, V3, V4) allowing to modify the circulation of the coolant according to the modes of cooling. 9. Device for cooling at least one battery (12) of a vehicle according to any one of claims 1 to 7, characterized in that said selection means are part of thermostats (VI, V2, V3, V4). to modify the circulation of the coolant according to the cooling modes. 10. Cooling device for at least one battery of a vehicle according to any one of claims 1 to 9, characterized in that the one or more other elements of the vehicle belong to the group comprising: electric motors; condensers; electronic modules; transmission oil; the air of supercharging. 11. Cooling device for at least one battery of a vehicle according to claim 10, characterized in that it comprises a main condenser (15) and an additional condenser (16), and in that said additional condenser (16). ) is cooled by the first radiator (11), at least in the second cooling mode. A method of cooling at least one battery of a vehicle, comprising a step of selecting between at least two cooling modes of said battery: a first cooling mode in which said battery is connected to a first cooling circuit, comprising at least a first radiator for cooling said battery; and a second cooling mode in which said battery is connected to a second cooling circuit comprising a refrigeration device, characterized in that said selecting step ensures, in said second cooling mode, a connection of said first radiator to at least one another element of said vehicle requiring cooling.