ELECTRIC OR HYBRID MOTOR VEHICLE COMPRISING A TWO-PART BATTERY AND ASSOCIATED METHOD

Abstract

The invention relates to an electric or hybrid motor vehicle comprising a battery tray (1) including a battery (2), said vehicle comprising a heating, ventilation, and air conditioning (HVAC) system (3) and a duct (4) connecting said HVAC system (3) and said battery tray (1), characterized in that said battery (2) comprises an upper part (2a) and a lower part (2b), the battery tray (1) comprising a first air passage above the upper part (2a), a second air passage between the upper part (2a) and the lower part (2b), and a third air passage below the lower part (2b), said duct (4) comprising a hatch (5) and a fan (6). Figure 1

Description

Title of the invention: ELECTRIC OR HYBRID MOTOR VEHICLE COMPRISING A TWO-PART BATTERY AND ASSOCIATED METHOD

[0001] The invention relates to the cooling, or heating, of batteries of electric or hybrid motor vehicles.

[0002] Various means of maintaining the temperature of automotive traction batteries are known in the prior art. Plate cooling involves using a plate bonded above or below the battery tray, through which a heat transfer fluid, such as glycol water, flows to regulate the temperature. This method, while cost-effective, requires considerable thickness. Immersion cooling involves immersing the battery in a moving dielectric liquid, cooled or heated outside the battery tray, offering good thermal management at the cost of increased mass and system complexity. Finally, air cooling uses air, conditioned or unconditioned, to cool the battery, either in direct contact with the cells or by circulating around the battery tray.Although this method is less expensive, its performance is limited and may depend on the airflow generated by the vehicle's speed.

[0003] The objective of the present invention is to remedy these drawbacks and to allow the maintenance of an optimal battery temperature at a lower cost without increasing the weight, or even by reducing the weight, of the motor vehicle.

[0004] To achieve this objective, the invention proposes an electric or hybrid motor vehicle comprising a battery tray including a battery, said vehicle comprising a front running gear and a rear running gear whose points of contact with the ground define a base plane defined by a first longitudinal direction corresponding to straight-line driving, by a second transverse direction orthogonal to the first longitudinal direction and a third vertical direction orthogonal to the first and second directions and oriented away from the ground, said vehicle comprising a heating-ventilation-air conditioning system and a duct connecting said heating-ventilation-air conditioning system and said battery tray, notable in that said battery comprises an upper part and a lower part,the upper part being positioned above the lower part along the third direction, the upper part being positioned at a predetermined non-zero distance from the lower part, the battery tray having a first air passage above the upper part, a , a second air passage between the upper and lower parts and a third air passage below the lower part, said duct having a hatch and a fan, said fan being positioned opposite said battery tray, said hatch being positioned between the heating-ventilation-air conditioning unit and said fan, said hatch being able to open to let in outside air or to close.

[0005] Thanks to the invention, the cooling of the battery can be ensured both by the intake of outside air via the hatch or by the heating-ventilation-air conditioning device.

[0006] Advantageously, the upper part and the lower part each comprise electrochemical cells, said upper part comprising an upper cover positioned above said electrochemical cells of the upper part, said lower part comprising a lower cover positioned below said electrochemical cells of the lower part.

[0007] This configuration allows air to circulate above and below each part of the battery. Thus, each end of the electrochemical cells is exposed to the air. The cooling or heating of said battery is therefore improved.

[0008] Advantageously, the upper cover and the lower cover are made of aluminum.

[0009] Aluminium is a good thermal conductor. In addition, aluminium exhibits high resistance to extreme temperatures.

[0010] Preferably, the upper cover and the lower cover each have four fastening means configured to secure said battery tray in said vehicle.

[0011] Advantageously, the first air passage, the second air passage and the third air passage each have a height of 10 mm along the third direction.

[0012] This is a sufficient height to allow air to circulate in the air passages, without significantly increasing the height of said battery.

[0013] Preferably, said battery includes fins.

[0014] The presence of fins increases the surface area of ​​exchange with the air of said battery tray, and therefore the efficiency of cooling or heating the battery.

[0015] Preferably, said conduit comprises a first parallelepiped part and a second infundibuliform part, the second part having a first section and a second section, the first section being positioned between said fan and said battery tray, the second section being positioned between the first section and said battery tray, the second section having dimensions greater than the dimensions of the first section.

[0016] This configuration allows for better air distribution in said battery tray, through the air passages.

[0017] Furthermore, the invention relates to a method for cooling the battery of an electric or hybrid motor vehicle previously described, said battery comprising a first temperature measurement sensor, said vehicle comprising a second sensor for measuring the outside temperature, remarkable in that said method comprises the following steps: - a step of measuring the temperature of said battery by said at least one first temperature measurement sensor, the hatch being closed; - a step of measuring the outside temperature by said second temperature measuring sensor; - a step of calculating the temperature difference between the outside temperature and the temperature of said battery when the temperature of said battery is greater than a first predetermined threshold value, the temperature difference being determined in absolute value; - a step of opening the hatch when the temperature difference is greater than a second predetermined threshold value or a step of activating said heating-ventilation-air conditioning device when the temperature difference is less than the second predetermined threshold value.

[0018] The method allows appropriate management of the state, open or closed, of the hatch and of the activation or not of the heating-ventilation-air conditioning device.

[0019] 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 battery tray when battery cooling is provided by a heating-ventilation-air conditioning system; - [Fig.2] schematically illustrates the battery tray shown in [Fig.1] when battery cooling is provided by a hatch.

[0020] Figure 1 schematically illustrates a battery tray 1 of an electric or hybrid motor vehicle. The battery tray 1 includes a traction battery 2. The vehicle comprises a front axle and a rear axle whose points of contact with the ground define a basic plane XY defined by a first longitudinal direction X corresponding to straight-line driving, a second transverse direction Y orthogonal to the first longitudinal direction X, and a third vertical direction Z orthogonal to the first direction X and the second direction Y and oriented away from the ground. The battery 2 comprises an upper part 2a and a lower part 2b. The part The upper part is positioned above the lower part 2b along the third direction Z. Thus, the battery tray 1 has a first air passage above the upper part 2a, a second air passage between the upper part 2a and the lower part 2b, and a third air passage below the lower part 2b. Preferably, the first, second, and third air passages each have a height of 10 mm. Optionally, the upper part 2a and the lower part 2b each have electrochemical cells for storing electrical energy in chemical form. The upper part 2a may optionally have an upper cover positioned above the electrochemical cells of the upper part 2a. Furthermore, the lower part 2b may have a lower cover positioned below the electrochemical cells of the lower part 2b.Preferably, the upper and lower covers are made of aluminum and each has four fastening means for securing the battery tray 1 in the vehicle. This facilitates the installation of the battery tray 1 in the vehicle. The vehicle has a heating, ventilation, and air conditioning (HVAC) unit 3 and a duct 4 connecting the HVAC unit 3 to the battery tray 1. The duct 4 has a flap 5 that can be opened and closed. In [Fig. 1], the flap 5 is closed. Therefore, air enters the duct 4 through the HVAC unit 3. This air may or may not be conditioned. The arrows in [Fig. 1] show the airflow path. When the heating, ventilation, and air conditioning unit 3 is providing cooling or heating of the battery 2, the vehicle may be in operation or stationary.Furthermore, said duct 4 includes a fan 6. Thus, when air enters said duct 4, the fan directs the air towards said battery tray 1 in order to cool or heat said battery 2 depending on the air temperature. After entering the battery tray, the air passes through the first air passage, the second air passage, and the third air passage. Thus, the electrochemical cells, positioned vertically along the third direction Z in said battery 2, are cooled or heated from their upper and lower ends, which improves the efficiency of the cooling or heating. Optionally, said battery 2 includes fins to increase the exchange surface area between said battery 2 and the air present in said battery tray 1.Thus, the cooling or heating of battery 2 is improved due to the rush of air into said fins. Preferably, the duct 4 comprises a first parallelepiped-shaped part 4a and a second funnel-shaped part 4b. The second part 4b comprises a first section and a second section. The first section is positioned opposite said fan 6. while the second section is positioned between said first section and said battery tray 1. The second section, closer to battery tray 1 compared to the first section, has larger dimensions than the first section, which is closer to the first part 4a of conduit 4.

[0021] In [Fig. 2], the flap 5 is open so that outside air enters said duct 4 and is directed towards the battery tray 1, via said fan 6. Using outside air to cool said battery 2 saves electrical current because the heating-ventilation-air conditioning unit 3 is switched off. To allow air to enter said flap 5, it is preferable that said vehicle be in running condition. Cooling said battery 1 by outside air is particularly effective when the vehicle is traveling at high speed, for example on a highway. Indeed, due to the vehicle's speed, a greater quantity of air enters the duct 4 via said flap 5.

[0022] The invention also relates to a method for cooling said electric or hybrid motor vehicle described above. The battery 2 includes a first temperature sensor, which is configured to measure the temperature inside said battery 2 in order to detect any excessive heating or cooling. In addition, said vehicle includes a second sensor for measuring the ambient temperature. This is the temperature of the environment surrounding said vehicle. The second temperature sensor can be located, for example, on the body of said vehicle. The method includes a step of measuring the battery temperature by said first temperature sensor and a step of measuring the ambient temperature by said second temperature sensor.During the step of measuring the temperature of said battery 2 and during the step of measuring the outside temperature, the hatch 5 is closed. By default, said hatch 5 is always closed to prevent a loss of vehicle aerodynamics. During a step of calculating the temperature difference, the difference between the outside temperature and the battery temperature is calculated in absolute value when the temperature of said battery is greater than a first predetermined threshold value. The method includes a step of opening said hatch 5 when the temperature difference is greater than a second predetermined threshold value. Alternatively, the method includes a step of activating the heating-ventilation-air conditioning device 3 when the temperature difference is less than the second predetermined threshold value.The process allows management of the state, open or closed, of said hatch 5 and of the operation of the heating-ventilation-air conditioning device 3.

Claims

Demands

1. Electric or hybrid motor vehicle comprising a battery tray (1) including a battery (2), said vehicle comprising a front running gear and a rear running gear whose points of contact with the ground define a base plane (XY) defined by a first longitudinal direction (X) corresponding to straight-line driving, by a second transverse direction (Y) orthogonal to the first longitudinal direction (X) and a third vertical direction (Z) orthogonal to the first direction (X) and to the second direction (Y) and is oriented away from the ground, said vehicle comprising a heating-ventilation-air conditioning device (3) and a duct (4) connecting said heating-ventilation-air conditioning device (3) and said battery tray (1), characterized in that said battery (2) comprises an upper part (2a) and a lower part (2b),the upper part (2a) being positioned above the lower part (2b) along the third direction (Z), the upper part (2a) being positioned at a predetermined non-zero distance from the lower part (2b), the battery tray (1) having a first air passage above the upper part (2a), a second air passage between the upper part (2a) and the lower part (2b) and a third air passage below the lower part (2b), said duct (4) having a flap (5) and a fan (6), said fan (6) being positioned opposite said battery tray (1), said flap (5) being positioned between the heating-ventilation-air conditioning unit (3) and said fan (6), said flap (5) being capable of opening to allow outside air in or closing.

2. Vehicle according to claim 1 characterized in that the upper part (2a) and the lower part (2b) each comprise electrochemical cells, said upper part (2a) comprising an upper cover positioned above said electrochemical cells of the upper part (2a), said lower part (2b) comprising a lower cover positioned below said electrochemical cells of the lower part (2b).

3. Vehicle according to claim 2 characterized in that the upper cover and the lower cover comprise aluminum.

4. Vehicle according to claim 2 or 3 characterized in that the upper cover and the lower cover each have four fastening means (7) configured to fix said battery tray (1) in said vehicle.

5. Vehicle according to any one of claims 1 to 4 characterized in that the first air passage, the second air passage and the third air passage each have a height of 10 mm along the third direction (Z).

6. Vehicle according to any one of claims 1 to 5 characterized in that said battery (2) comprises fins.

7. Vehicle according to any one of claims 1 to 6 characterized in that said conduit (4) comprises a first parallelepiped part (4a) and a second funnel-shaped part (4b), the second part (4b) having a first section and a second section, the first section being positioned between said fan (6) and said battery tray (1), the second section being positioned between the first section and said battery tray (1), the second section having dimensions greater than the dimensions of the first section.

8. A method for cooling the battery (2) of an electric or hybrid motor vehicle according to any one of claims 1 to 7, said battery (2) comprising a first temperature measuring sensor, said vehicle comprising a second sensor for measuring the outside temperature, characterized in that said method comprises the following steps: - a step of measuring the temperature of said battery (2) by said at least one first temperature measuring sensor, the hatch (5) being closed; - a step of measuring the outside temperature by said second temperature measuring sensor; - a step of calculating the temperature difference between the outside temperature and the temperature of said battery when the temperature of said battery is greater than a first predetermined threshold value, the temperature difference being determined in absolute value;- a step of opening the hatch (5) when the temperature difference is greater than a second predetermined threshold value or a step of actuation of said device; heating-ventilation-air conditioning (3) when the temperature difference is less than the second predetermined threshold value.

Images