DEVICE FOR THE THERMOREGULATION OF BATTERIES IN ELECTRIC OR HYBRID VEHICLES AND METHOD IMPLEMENTING SUCH A DEVICE

Abstract

The invention relates to a device for the thermoregulation of a battery (1) of an electric or hybrid vehicle and a method implementing the device. The device comprises: - a battery cell (10); - a sprayer (20) configured to spray a fluid onto the battery cell (10), the sprayer (20) being connected to a fluid circuit (10) comprising a first fitting and a second fitting, the fluid circuit (10) comprising a pressure sensor configured to measure the fluid pressure in the fluid circuit (10), the first fitting comprising a filter, the second fitting comprising a valve configured to be in a closed state and to be in an open state, the valve being in the closed state by default. Figure 1

Description

Title of the invention: DEVICE FOR THE THERMOREGULATION OF A BATTERY ELECTRIC OR HYBRID VEHICLE AND METHOD IMPLEMENTING SUCH A DEVICE

[0001] The invention relates to motor vehicles with partial or full electric propulsion, and more particularly to the battery trays of these vehicles and their cooling.

[0002] Patent application CN117048283 describes a device comprising a sprayer and a battery including a nozzle configured to spray a fluid onto the battery. The sprayer is connected to a fluid circuit including a filter and a solenoid valve.

[0003] That said, in the event of an obstruction in the fluid circuit, particularly by fine particles, such a filter limits the fluid flow in the fluid circuit. Consequently, for example in the event of thermal runaway, an uncontrolled increase in the temperature of a battery cell propagating to adjacent battery cells is more difficult to regulate, potentially causing serious damage to the battery and compromising the safety of the vehicle and its occupants.

[0004] The objective of the invention is to overcome this drawback and ensure thermal regulation of the vehicle battery.

[0005] To achieve this objective, the invention proposes a device for the thermoregulation of an electric or hybrid vehicle battery, the device comprising: - a battery cell; - a sprayer configured to spray a fluid onto the battery cell, the device being characterized in that the sprayer is connected to a fluid circuit comprising: - a first connection including a filter; - a second fitting including a valve configured to be in a closed state or to be in an open state, the valve being in the closed state by default; - the fluid circuit including a pressure sensor configured to measure fluid pressure in the fluid circuit.

[0006] Such a device makes it possible to control the temperature of the battery of an electric or hybrid vehicle, the temperature of the battery cell being maintained in such a way as to prolong its lifespan and improve its performance. The sprayer diffuses a fluid onto the battery cell in such a way as to prevent any thermal runaway of the battery cell, in particular by increasing the thermal dissipation of the battery cell.

[0007] Advantageously, the second fitting includes an auxiliary filter.

[0008] This auxiliary filter provides protection against impurities and unwanted particles of a size that could clog the device, for example the sprayer.

[0009] Advantageously, the fluid circuit includes a non-return valve.

[0010] Advantageously, the valve is a solenoid valve configured to be in the state closed to a first command and to be in the open state to a second command.

[0011] Advantageously, the valve includes a spring and a flapper configured to be in an open state and in a closed state, the flapper being configured to be in the closed state by action of the spring when the pressure value of the fluid in the heat transfer circuit is less than a predetermined actuation pressure value, the valve being in the closed state, and to be in the open state by action of the spring when the pressure value of the fluid in the heat transfer circuit is greater than a predetermined actuation pressure value, the valve being in the open state.

[0012] The invention also proposes a method for the thermoregulation of an electric or hybrid vehicle battery, implementing a device defined as above, the method comprising the following steps: - a step of measuring a fluid pressure value in the fluid circuit by the pressure sensor; - a step of switching the valve from the closed state to the open state after a predetermined time when the measured pressure value is greater than a predetermined pressure value.

[0013] Such control of the fluid pressure in the fluid circuit provides protection against damage to the device due to overpressures and ensures reliable and durable operation of the device, particularly in the event of obstruction of the fluid circuit.

[0014] Advantageously, the predetermined duration is less than or equal to 3 min.

[0015] The predetermined duration is chosen so as to allow time for the particles in the fluid to accumulate in the filter of the first fitting while ensuring that this accumulation does not cause an overpressure which would harm the fluid circuit, the fluid free of these particles relieving the pressure of the fluid circuit by supplying the second fitting when the valve switches from the closed state to the open state.

[0016] The invention also relates to a computer program comprising program code instructions for executing the steps of the process defined as above, when the program is running on a computer.

[0017] The invention further relates to a vehicle comprising: - a device defined as above; - a control unit electronically connected to the device for battery thermoregulation, the control unit comprising means for acquisition, processing by software instructions stored in memory as well as control means required for the implementation of the computer program defined as above.

[0018] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig. 1] schematically illustrates a front view of a sprayer and a battery cell of a device according to an embodiment of the invention; - [Fig.2] schematically illustrates a fluid circuit of a device according to an embodiment of the invention; - [Fig.3] illustrates a flowchart representing the steps of a process for the thermoregulation of an electric or hybrid vehicle battery, according to an embodiment of the invention.

[0019] According to the invention, a device for the thermoregulation of a battery 1 of an electric or hybrid vehicle comprises a battery cell 10 and a sprayer 20.

[0020] Fig. 1 illustrates a cross-sectional view of a battery 1 according to one embodiment. With reference to [Fig.1], battery 1 comprises a plurality of battery cells 10 extending along a vertical axis Z and arranged along a horizontal axis Y. Battery 1 also comprises a collection surface.

[0021] The sprayer 20 is configured to spray a fluid onto the battery cell 10. In this case, the sprayer 20 includes a nozzle configured to spray the battery cell 10, particularly its top, so that the fluid flows along the vertical axis Z until it reaches the collection surface. Thus, the battery cell 10 is partially immersed to a depth of approximately 5% to 30% of its height.

[0022] Preferably, the nozzle forms an angle between -20 and +5 degrees with respect to the horizontal axis Y. This allows spraying ensuring homogeneous coverage on the surface of the battery cell 10 and a low fluid film thickness, thus promoting efficient heat dissipation without requiring a large amount of fluid.

[0023] In practice the fluid used is a dielectric fluid comprising for example polyalphaolefins or ester-based compounds so as to avoid a short circuit in the battery 1 when the fluid is in direct contact with the battery cell 10 while having sufficient thermal dissipation to remove the heat generated by the battery cell 10.

[0024] The sprayer 20 is connected to a fluid circuit 10 comprising a first fitting 10A and a second fitting 10B. The first fitting 10A includes a first fluid inlet and a first fluid outlet. Similarly, the second fitting 10B includes a second fluid inlet and a second fluid outlet.

[0025] Figure 2 illustrates the fluid circuit 10 according to an embodiment of the invention. The first fluid inlet and the second fluid inlet are connected to the pump, which is itself connected to the collection surface.

[0026] The first fitting 10A includes a filter 11A. The filter 11A is made from temperature- and corrosion-resistant materials, such as stainless steel or polymers. The structure of the filter 11A includes a finely woven screen or a synthetic fiber filter medium configured to capture fine particles without restricting fluid flow.

[0027] Preferably, the fluid circuit 10 includes a non-return valve 13. With reference to [Fig.2], the first fitting 10A includes a non-return valve 13 between the first fluid inlet and the filter 11A in the fluid circuit 10.

[0028] The fluid circuit 10 includes a pressure sensor configured to measure the pressure of the fluid in the fluid circuit 10. The pressure sensor is advantageously placed between the first fluid inlet and the filter 11A in the fluid circuit 10. Alternatively, the pressure sensor is placed between the filter 11A and the first fluid outlet in the fluid circuit 10.

[0029] The second fitting 10B includes a valve 12 configured to be in a closed state and to be in an open state, the valve 12 being by default in the closed state.

[0030] Preferably, the second fitting 10B includes an auxiliary filter 1 IB. With reference to [Fig.2], the auxiliary filter 11B is advantageously located between the valve 12 and the second fluid outlet.

[0031] Preferably, the valve 12 is a solenoid valve configured to be in the closed state on a first command and to be in the open state on a second command.

[0032] According to another embodiment, the fluid circuit 10 includes a valve 12 comprising a spring and a flapper.

[0033] The valve is configured to be in the closed state by spring action when the fluid pressure in the heat transfer circuit is less than a predetermined actuation pressure. Thus, valve 12 is in the closed state.

[0034] The valve is also configured to be in the open state by spring action when the fluid pressure is greater than the predetermined pressure. Thus, valve 12 is in the open state.

[0035] Figure [1] illustrates a flowchart of a method for the thermoregulation of battery 1 of an electric or hybrid vehicle, the steps of the method being described below according to an embodiment of the invention.

[0036] In a measurement step El, a fluid pressure value in the fluid circuit 10 is measured by the pressure sensor.

[0037] In a switching step E2, the valve 12 switches from the closed state to the open state after a predetermined time when the measured pressure value is greater than a predetermined pressure value.

[0038] Preferably, the predetermined duration is less than or equal to 3 min.

Claims

Demands

1. Device for thermoregulating an electric or hybrid vehicle battery, the device comprising: - a battery cell (10); - a sprayer (20) configured to spray a fluid onto the battery cell (10), the device being characterized in that the sprayer (20) is connected to a fluid circuit (10) comprising: - a first fitting (10A) comprising a filter (1 IA); - a second fitting (10B) comprising a valve (12) configured to be in a closed state or to be in an open state, the valve (12) being by default in the closed state; - the fluid circuit (10) comprising a pressure sensor configured to measure a fluid pressure in the fluid circuit (10).

2. Device according to claim 1, characterized in that the second fitting (10B) includes an auxiliary filter (11B).

3. Device according to claim 1 or 2, characterized in that the fluid circuit (10) includes a non-return valve (13).

4. Device according to any one of claims 1 to 3, characterized in that the valve (12) is a solenoid valve configured to be in the closed state on a first command and to be in the open state on a second command.

5. Device according to any one of claims 1 to 3, characterized in that the valve (12) comprises a spring and a flapper configured to be in an open state and in a closed state, the flapper being configured to be in the closed state by action of the spring when the fluid pressure value in the heat transfer circuit is less than a predetermined actuation pressure value, the valve (12) being in the closed state, and to be in the open state by action of the spring when the fluid pressure is greater than the predetermined pressure, the valve (12) being in the open state.

6. Method for thermoregulation of electric or hybrid vehicle battery, implementing a device according to any one of claims 1 to 4, the method comprising the following steps: - a measurement step (El) of a fluid pressure value in the fluid circuit (10) by the pressure sensor;

7.

8.

9. - a switching step (E2) of the valve (12) from the closed state to the open state after a predetermined time when the measured pressure value is greater than a predetermined pressure value. The method according to claim 7, characterized in that the predetermined time is less than or equal to 3 minutes. Computer program comprising program code instructions for executing the steps of the process according to claim 6 or 7, when the program runs on a computer. Vehicle includes: - a device according to any one of claims 1 to 4; - a control unit electronically connected to the device for battery thermoregulation, the control unit comprising means for acquisition, processing by software instructions stored in memory and control means required for the implementation of the computer program according to claim 8.

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