Electric vehicle thermal management auxiliary system suitable for harsh weather conditions and method of use

Abstract

The application provides a kind of electric vehicle thermal management auxiliary system suitable for severe weather conditions, including parking space (1), nozzle array, refrigeration and heating unit (3), liquid collecting tank (4), pump (5) and heat exchange chamber (6). By communicating with electric vehicle online in real time to obtain the temperature of battery pack: if the temperature of battery pack is less than or equal to the first temperature threshold or greater than or equal to the second temperature threshold, make the refrigeration and heating unit (3) work in heating mode or cooling mode, start the pump (5) and open the valve (9) corresponding to the nozzle (2), spray liquid to the corresponding area of chassis, until the temperature of battery pack is greater than the first temperature threshold or less than the second temperature threshold. The application can also obtain the position of wheel through pressure sensor (11), identify the position of battery pack in horizontal direction, selectively activate the liquid spraying function of nozzle (2) directly below battery pack, so it has the advantages of high precision, high energy efficiency and liquid recovery rate, no adverse effects on the outside world.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric vehicle thermal management, in particular to an electric vehicle thermal management auxiliary system suitable for severe weather conditions and a use method thereof. BACKGROUND

[0002] Currently, electric vehicles mainly use lithium ion battery packs located on their chassis for power supply. The charging and discharging of lithium ion battery packs need to be carried out in a suitable temperature environment. Although the electric vehicle itself has certain thermal management functions during operation, when the electric vehicle is charging or parked in an environment with high or low temperature, the self-thermal management function of the electric vehicle has great limitations due to limited refrigeration and heating capacity, time and power consumption, etc. Therefore, it is necessary to develop an additional electric vehicle battery thermal management auxiliary system to overcome the limitations of the self-thermal management function of the electric vehicle under severe weather conditions of excessively high or low temperature. SUMMARY

[0003] The main purpose of the present application is to provide an electric vehicle thermal management auxiliary system suitable for severe weather conditions and a use method thereof, aiming to solve the technical problem of limited self-thermal management function of electric vehicles in an environment with high or low temperature, thereby providing auxiliary thermal management for the charging process and starting demand after parking of electric vehicles.

[0004] To achieve the above-mentioned purpose, the present application provides an electric vehicle thermal management auxiliary system suitable for severe weather conditions, which is used to provide thermal management function for the battery pack located above the chassis of the electric vehicle, and the thermal management auxiliary system comprises a parking space, a nozzle array, a refrigeration and heating unit, a liquid collecting tank, a pump and a heat exchange chamber.

[0005] The nozzle array is composed of a plurality of nozzles and is uniformly distributed on the surface of the parking space.

[0006] Each nozzle in the nozzle array is respectively connected through a branch pipe and a main pipe, and the main pipe takes liquid from the heat exchange chamber through the pump.

[0007] A valve is respectively arranged on the branch pipe corresponding to each nozzle.

[0008] The liquid collecting tank is in communication with the heat exchange chamber, and is used to collect the liquid flowing back to the surface of the parking space after being sprayed by the nozzle array and make it return to the heat exchange chamber.

[0009] The refrigeration and heating unit is provided with a heat exchange pipe, and the heat exchange pipe is immersed in the liquid in the heat exchange chamber to cool or heat the liquid.

[0010] Optionally, in the electric vehicle thermal management auxiliary system suitable for severe weather conditions, the heat exchange chamber is located below the liquid collecting tank, so that the liquid collected by the liquid collecting tank naturally flows into the heat exchange chamber under the action of gravity.

[0011] Optionally, the electric vehicle thermal management auxiliary system for severe weather conditions, the part where the sump communicates with the heat exchange chamber is provided with a filter screen to filter the solid impurities that may be carried by the liquid delivered by the sump.

[0012] Optionally, the electric vehicle thermal management auxiliary system for severe weather conditions, the surface of the parking space has a slope, and the sump is arranged at the lowest part of the surface of the parking space, so that the liquid on the surface of the parking space naturally flows into the sump under the action of gravity.

[0013] Optionally, the electric vehicle thermal management auxiliary system for severe weather conditions, the liquid sprayed by the nozzle array is water or an aqueous solution.

[0014] Further, when the liquid sprayed by the nozzle array is an aqueous solution, the solute includes inorganic salts and corrosion inhibitors, wherein the inorganic salts are used to lower the freezing point of water, and the corrosion inhibitors are used to slow down the corrosion effect of inorganic salts on the chassis of the electric vehicle.

[0015] Optionally, the electric vehicle thermal management auxiliary system for severe weather conditions, the thermal management auxiliary system further comprises a surface pressure sensor array composed of a plurality of pressure sensors and uniformly distributed on the surface of the parking space.

[0016] Optionally, the electric vehicle thermal management auxiliary system for severe weather conditions, the thermal management auxiliary system further comprises a controller, which is electrically connected with the pressure sensor array, the refrigeration and heating unit, the pump and the valves arranged on all branch pipes, and can communicate with the electric vehicle.

[0017] In addition, to achieve the above-mentioned purpose, the application also provides a use method of the electric vehicle thermal management auxiliary system for severe weather conditions, when the electric vehicle is parked on the parking space and issues a thermal management auxiliary system use demand, the following steps are sequentially executed:

[0018] Step S1, collect the pressure values obtained by each pressure sensor in the pressure sensor array, and obtain the tire position distribution information of the electric vehicle from the pressure values;

[0019] Step S2, obtain the vehicle model information of the electric vehicle by communicating with the electric vehicle, and combine the tire position distribution information obtained in step S1 to calculate the projection area of the battery pack on the parking space, wherein the vehicle model information includes the relative position information of the battery pack and each tire in the horizontal direction;

[0020] Step S3, find all the nozzles within the orthographic projection area of the battery pack on the parking space;

[0021] Step S4, communicating with the electric vehicle online in real time to obtain the temperature of the battery pack: if the temperature of the battery pack is less than or equal to the first temperature threshold, the refrigeration and heating unit is operated in the heating mode, the pump is started, and the valves corresponding to all the nozzles in step S3 are opened to spray liquid to the corresponding areas of the chassis until the temperature of the battery pack is greater than the first temperature threshold; if the temperature of the battery pack is greater than or equal to the second temperature threshold, the refrigeration and heating unit is operated in the refrigeration mode, the pump is started, and the valves corresponding to all the nozzles in step S3 are opened to spray liquid to the corresponding areas of the chassis until the temperature of the battery pack is less than the second temperature threshold; the first temperature threshold is less than the second temperature threshold.

[0022] Optionally, the use method of the electric vehicle thermal management auxiliary system suitable for severe weather conditions described above, step S1 specifically includes the following sub-steps:

[0023] Sub-step S1.1, placing the pressure sensor with a pressure value greater than the pressure threshold Pc in the data set, each element in the data set corresponds to a pressure value and a position coordinate of a pressure sensor;

[0024] Sub-step S1.2, randomly selecting an element from the data set, respectively calculating the distance between the element and all the remaining elements, and counting the elements with a distance value less than the distance threshold Lc from the element into the same element group as the element, wherein the distance between any two elements is the distance between the corresponding position coordinates of the two elements;

[0025] Sub-step S1.3, deleting the elements in the data set that have been counted into the element group;

[0026] Sub-step S1.4, repeating sub-steps S1.2 to S1.3 until the number of elements in the data set is 0;

[0027] Sub-step S1.5, sequentially calculating the center coordinates of each element group, i.e., obtaining the position coordinates of each tire of the electric vehicle, wherein the center coordinates of any element group are the geometric center of the position coordinates corresponding to all the elements in the element group.

[0028] The beneficial effects of the technical scheme of the present application will be introduced below.

[0029] First, two use scenarios of electric vehicles are assumed.

[0030] Scenario one: the electric vehicle drives for a period of time in a high-temperature environment, and the battery pack is insufficient. The vehicle is parked outdoors to charge. At the beginning of charging, the temperature of the battery pack is high, and the temperature needs to be reduced to an appropriate temperature before normal charging can be carried out. At this time, if the cooling function of the electric vehicle itself is used to cool the battery pack, firstly, the refrigeration power is limited; secondly, the remaining power of the electric vehicle is already very small, and cannot bear the power required for refrigeration. The charging process is fast charging, and the battery pack generates a lot of heat. At this time, if the cooling function of the electric vehicle itself is used to cool the battery pack, firstly, the refrigeration power is limited; secondly, it will inevitably reduce the charging current that the battery pack can share, and reduce the charging rate of the battery pack itself.

[0031] Scenario two: the electric vehicle is parked for a long time in a cold outdoor environment, and the owner needs to drive away. Because the battery pack is in a low-temperature state, it cannot provide enough discharge power to the electric vehicle to meet its driving needs in a short time.

[0032] Therefore, it is necessary to provide external functional heat management auxiliary services for electric vehicles in parking spaces to meet the needs of fast charging and fast starting after long parking in harsh weather conditions such as excessively high or low ambient temperature.

[0033] The technical means for providing auxiliary heat management for electric vehicles is to store liquid in the heat exchange chamber, pump the liquid to the main pipe, and open the valve of the corresponding branch pipe according to the needs, so that the liquid is sprayed from the corresponding nozzle along the branch pipe to the bottom plate below the battery pack area of the electric vehicle. The high-speed flowing liquid can bring a large convective heat transfer effect, so it can quickly cool or heat the corresponding area of the bottom plate, and further cool or heat the battery pack by means of heat conduction between the bottom plate and the battery pack. After the liquid washes the bottom plate, it is reflected back and falls on the parking space surface with a slope, is collected by the liquid collecting groove at the lowest part of the parking space surface, and finally flows back to the heat exchange chamber. After heat exchange with the heat exchange pipe of the refrigeration and heating unit, it is recycled. Whether the refrigeration and heating unit works in refrigeration mode or heating mode is determined by real-time communication between the heat management auxiliary system and the electric vehicle: if the temperature of the battery pack is less than or equal to the first temperature threshold, it works in heating mode; if the temperature of the battery pack is greater than or equal to the second temperature threshold, it works in refrigeration mode.

[0034] The liquid used as the heat exchange medium is water or aqueous solution. If there are days when the local temperature is below 0℃, aqueous solution is used, and the solutes include inorganic salts and corrosion inhibitors, wherein the inorganic salts are used to lower the freezing point of water, and the corrosion inhibitors are used to slow down the corrosion effect of inorganic salts on the bottom plate of the electric vehicle.

[0035] In order to improve the operation accuracy and efficiency of the system, the liquid needs to be sprayed just to the bottom plate area directly below the battery pack. Otherwise, if the liquid is sprayed to other areas of the bottom plate, there is a waste phenomenon; even if the liquid is sprayed to the area outside the bottom plate, it may eventually be sprayed to the vehicle body and surrounding pedestrians, objects, not only causing waste, leading to difficult recycling of the liquid, but also bringing adverse effects. Therefore, the real parking position of the electric vehicle needs to be obtained, and the relative distance of the tire and the battery pack in the two orthogonal directions of the horizontal plane is read from the vehicle model information, so as to accurately calculate the position of the battery pack.

[0036] In the current known technical means, the parking position information of the electric vehicle can be recognized by means such as laser or image recognition, but these means are easily disturbed by rain, fog, sunlight and other external disturbances, and the surface dirt of the vehicle itself and the environment will also bring certain disturbance to the recognition. In the technical scheme of the present application, the parking position information of the electric vehicle is obtained by knowing the tire position: if the pressure value measured by the pressure sensor at some position of the parking space surface is greater than the pressure threshold Pc, it indicates that there is pressure generated by the tire at these positions, so the pressure sensor with a pressure value greater than the pressure threshold Pc is placed in the data set; further, considering that there is a distance between each contact surface of the tire and the parking space surface, so any element is taken from the data set, the distance between the element and all the remaining elements is calculated respectively, and the elements with a distance value less than the distance threshold Lc and the element are counted into the same element group, considering that the pressure sensors in the same element group correspond to the same tire; then the elements in the data set that have been counted into the element group are deleted, and the element grouping and element deletion steps after grouping are repeated until the number of elements in the data set is 0; finally, the center coordinates of each element group are calculated in turn, that is, the tire position coordinates of the electric vehicle are obtained.

[0037] Therefore, the present application proposes a technical scheme of a thermal management auxiliary system and a method for using the same for the demand of rapid use of the electric vehicle after charging and long-time parking under harsh weather conditions such as high or low temperature. The thermal management auxiliary system uses external functions and does not depend on the functions of the electric vehicle itself, which overcomes the problem of insufficient charging and discharging capacity of the battery pack under harsh weather conditions; the refrigeration and heating unit of the thermal management auxiliary system can be made larger, and can provide larger refrigeration and heating capacity than the air conditioning system of the electric vehicle itself, so it works quickly; the thermal management auxiliary system uses the pressure signal generated by the pressure sensor arranged on the parking space surface by the tire, and obtains the vehicle model information through communication, identifies the position of the battery pack in the horizontal direction, and selectively activates the liquid spraying function of the nozzle directly below the battery pack, so it has the advantages of high precision, high energy efficiency and liquid recovery rate, and no adverse effects on the outside world. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1A schematic diagram of the constitution of the electric vehicle thermal management auxiliary system suitable for severe weather conditions in the embodiment of the present application.

[0039] Figure 2 A schematic diagram of the constitution of the liquid delivery pipe network of the electric vehicle thermal management auxiliary system suitable for severe weather conditions in the embodiment of the present application.

[0040] Figure 3 A flow chart of the method for using the electric vehicle thermal management auxiliary system suitable for severe weather conditions in the embodiment of the present application.

[0041] Figure 4 A schematic diagram of the constitution of the electric vehicle thermal management auxiliary system suitable for severe weather conditions in the embodiment of the present application. Figure 3 A flow chart of step S1 in the embodiment of the present application.

[0042] In the figure: 1 - parking space, 2 - nozzle, 3 - refrigeration and heating unit, 4 - liquid collecting tank, 5 - pump, 6 - heat exchange chamber, 7 - main pipe, 8 - branch pipe, 9 - valve, 10 - filter screen, 11 - pressure sensor, 31 - heat exchange pipe. DETAILED DESCRIPTION

[0043] The present application will be further described below in conjunction with the accompanying drawings and embodiments.

[0044] As shown in Figure 1 and Figure 2 , the present application provides an electric vehicle thermal management auxiliary system suitable for severe weather conditions, which is used to provide thermal management function for the battery pack located above the chassis of the electric vehicle, characterized in that the thermal management auxiliary system comprises a parking space 1, a nozzle array, a refrigeration and heating unit 3, a liquid collecting tank 4, a pump 5 and a heat exchange chamber 6.

[0045] The nozzle array is composed of a plurality of nozzles 2 and is uniformly distributed on the surface of the parking space 1.

[0046] Each nozzle 2 in the nozzle array is respectively connected through a branch pipe 8 and a main pipe 7, and the main pipe 7 takes liquid from the heat exchange chamber 6 through the pump 5.

[0047] Each nozzle 2 is respectively provided with a valve 9 on the corresponding branch pipe 8.

[0048] The liquid collecting tank 4 is in communication with the heat exchange chamber 6, and is used to collect the liquid flowing back to the surface of the parking space 1 after being sprayed by the nozzle array and make it return to the heat exchange chamber 6.

[0049] The refrigeration and heating unit 3 is provided with a heat exchange pipe 31, which is immersed in the liquid in the heat exchange chamber 6 to cool or heat the liquid.

[0050] Preferably, the heat exchange chamber 6 is located below the sump 4 so that the sump 4 collects the obtained liquid to flow into the heat exchange chamber 6 naturally under the action of gravity. Further, the sump 4 has a certain slope, wherein the end of the sump 4 communicating with the heat exchange chamber 6 is the lowest position of the sump 4, thereby making it more convenient for the sump 4 to collect the obtained liquid to flow into the heat exchange chamber 6 naturally under the action of gravity.

[0051] Preferably, the part of the sump 4 communicating with the heat exchange chamber 6 is provided with a filter screen 10 to filter solid impurities possibly contained in the liquid delivered by the sump 4.

[0052] Preferably, the surface of the parking space 1 has a slope, and the sump 4 is located at the lowest position of the surface of the parking space 1 so that the liquid on the surface of the parking space 1 flows into the sump 4 naturally under the action of gravity.

[0053] In one embodiment, the surface of the parking space 1 has a shape of being low in the center and high on both sides, and the sump 4 is located in the center of the surface of the parking space 1; in another embodiment, the surface of the parking space 1 has a shape of being high in the center and low on both sides, and two sumps 4 are located at the two side edges of the surface of the parking space 1 and communicate with the heat exchange chamber 6 after being merged together.

[0054] Preferably, the liquid sprayed by the nozzle array is water or an aqueous solution. Further, when the liquid sprayed by the nozzle array is an aqueous solution, the solute includes inorganic salts and corrosion inhibitors, wherein the inorganic salts are used to lower the freezing point of water, and the corrosion inhibitors are used to slow down the corrosion effect of the inorganic salts on the chassis of the electric vehicle. The inorganic salts can be sodium chloride, and the main components of the corrosion inhibitors can include any one of molybdate, tungstate and azole substances.

[0055] Preferably, the thermal management auxiliary system further includes a surface pressure sensor array composed of a plurality of pressure sensors 11 and uniformly distributed on the surface of the parking space 1.

[0056] Further, the thermal management auxiliary system further includes a controller (not shown in the figure), which is electrically connected with the pressure sensor array, the refrigeration and heating unit 3, the pump 5 and the valves 9 provided on all the branch pipes 8, and can communicate with the electric vehicle.

[0057] Figure 1 The nozzles 2 and the pressure sensors 11 in the figure are only schematic, and the number thereof does not represent the actual number.

[0058] Figure 2 In the figure, only the liquid delivery pipe network is schematic, and all the nozzles 2, the corresponding branch pipes 8 and the valves 9 cannot be drawn due to the length of the article, and are replaced by ellipses “…”.

[0059] As shown in FIG. 1, the thermal management auxiliary system for electric vehicles includes a parking space 1, a refrigeration and heating unit 3, a pump 5, a sump 4, a heat exchange chamber 6, a plurality of nozzles 2 and a plurality of pressure sensors 11. Figure 3As shown, the method for using the above-mentioned electric vehicle thermal management auxiliary system suitable for harsh weather conditions is as follows: when the electric vehicle is parked on the parking space 1 and the use demand of the thermal management auxiliary system is issued, the following steps are sequentially executed:

[0060] Step S1, collect the pressure values obtained by each pressure sensor 11 in the pressure sensor array, and obtain the tire position distribution information of the electric vehicle from the pressure values;

[0061] Step S2, obtain the vehicle model information of the electric vehicle by communicating with the electric vehicle, and combine the tire position distribution information obtained in step S1 to calculate the projection area of the battery pack of the electric vehicle on the parking space 1, wherein the vehicle model information includes the relative position information of the battery pack and each tire in the horizontal direction;

[0062] Step S3, find all nozzles 2 within the orthographic projection area of the battery pack on the parking space 1;

[0063] Step S4, communicate with the electric vehicle online in real time to obtain the temperature of the battery pack: if the temperature of the battery pack is less than or equal to the first temperature threshold, make the refrigeration and heating unit 3 work in the heating mode, start the pump 5 and open the valves 9 corresponding to all nozzles 2 in step S3 to spray liquid to the corresponding area of the chassis until the temperature of the battery pack is greater than the first temperature threshold; if the temperature of the battery pack is greater than or equal to the second temperature threshold, make the refrigeration and heating unit 3 work in the refrigeration mode, start the pump 5 and open the valves 9 corresponding to all nozzles 2 in step S3 to spray liquid to the corresponding area of the chassis until the temperature of the battery pack is less than the second temperature threshold; the first temperature threshold is less than the second temperature threshold.

[0064] As shown, further, step S1 specifically includes the following sub-steps: Figure 4

[0065] Sub-step S1.1, place the pressure sensors 11 with pressure values greater than the pressure threshold Pc in the data set, and each element in the data set corresponds to a pressure value and position coordinates of a pressure sensor 11;

[0066] Sub-step S1.2, randomly select an element in the data set, calculate the distance between the element and all remaining elements respectively, and count the elements with distance values less than the distance threshold Lc and the element into the same element group, wherein the distance between any two elements is the distance between the corresponding position coordinates of the two elements;

[0067] Sub-step S1.3, delete the elements in the data set that have been counted into the element group;

[0068] Sub-step S1.4, repeat sub-steps S1.2 to S1.3 until the number of elements in the data set is 0; ​

[0069] Sub-step S1.5, the center coordinates of each element group are calculated in turn, i.e. the tire position coordinates of the electric vehicle are obtained, wherein the center coordinates of any element group are the geometric center of the position coordinates corresponding to all elements in the element group.

[0070] Specifically, each element in the data set can be represented as a dictionary-form data structure: {No:(x,y)}, wherein No is the number of the pressure sensor 11, and x and y represent the horizontal and vertical coordinates of the corresponding pressure sensor number, respectively. If the coordinates of two pressure sensors 11 are (x1, y1) and (x2, y2), respectively, the distance between them is:

[0071] The principle of sub-step S1.2 is that the different tires of the electric vehicle have a certain distance, and the elements in the data set whose distance values are less than the distance threshold Lc also correspond to the relevant pressure sensors 11 under the same tire as the selected element.

[0072] The horizontal coordinate of the center coordinates of a certain element group is the arithmetic mean of the horizontal coordinates corresponding to all elements in the element group; and the vertical coordinate of the center coordinates of a certain element group is the arithmetic mean of the vertical coordinates corresponding to all elements in the element group.

[0073] On the basis of obtaining the tire position coordinates of the electric vehicle, the coordinate information of the battery pack edge is calculated in combination with the design size information of the model to which the electric vehicle belongs. It should be pointed out that in the technical solution of the present application, the electric vehicle is parked on the parking space 1 according to the specified head direction, and the parking space 1 usually has a mark or clear information for the car owner to park according to the specification. If the direction of the electric vehicle is opposite to the specified direction, the communication between the car machine and the thermal management auxiliary system is needed to inform that the direction is opposite to the specified direction, so that the thermal management auxiliary system can accurately determine the coordinate information of the battery pack edge.

[0074] For example, in one embodiment, the coordinates of four tires of an electric vehicle parked according to the standard are (a1, b1), (a2, b2), (a3, b3), and (a4, b4), wherein b1 and b2 are approximately equal, and b3 and b4 are approximately equal. According to the coordinate setting rule on parking space 1, the coordinates of the two front wheels are (a1, b1) and (a2, b2), and the coordinates of the two rear wheels are (a3, b3) and (a4, b4). By consulting the information of the electric vehicle model, it is known that the positive projection of the battery pack is a rectangle, and there is a distance information between the four vertices of the rectangle and the four tire coordinates on the two orthogonal coordinate axes in the horizontal direction, and accordingly the coordinate information of the edge of the battery pack can be obtained. Since the controller (not shown in the figure) also stores the nozzle 2 number and its coordinate information on the surface of the parking space 1 in advance, the positive projection area of the battery pack on the parking space 1 is found on this basis to activate the valves 9 corresponding to all the nozzles 2 within the positive projection area of the battery pack on the parking space 1, and the nozzles 2 spray liquid.

[0075] On the contrary, in another embodiment, the head of the electric vehicle on the parking space 1 is opposite to the default standard direction, and the electric vehicle tells the thermal management auxiliary system through the car machine, in which case the front and rear wheel judgment rules need to be exchanged based on the default rules.

[0076] Preferably, considering the liquid evaporation phenomenon, the electric vehicle thermal management auxiliary system further comprises a liquid storage tank in communication with the heat exchange chamber 6 and above the position of the heat exchange chamber 6, a liquid level sensor is arranged in the heat exchange chamber 6, a valve 9 is arranged at the communication position of the liquid storage tank and the heat exchange chamber 6, and the liquid level sensor and the valve 9 are electrically connected with the controller. When the liquid level sensor detects that the liquid level in the heat exchange chamber 6 is lower than the liquid level threshold, the valve 9 is opened to put the stored liquid in the liquid storage tank into the heat exchange chamber 6, and the valve 9 is closed only when the liquid level in the heat exchange chamber 6 is greater than or equal to the liquid level threshold.

[0077] Embodiment

[0078] Please refer to Figures 1 to 4 A more specific embodiment will be understood.

[0079] In this embodiment, the liquid sprayed by the nozzle array is water, the first temperature threshold is 10℃, the second temperature threshold is 40℃, the pressure threshold Pc is 50kPa, and the distance threshold Lc is 0.3m. The electric vehicle thermal management auxiliary system relies on power grid power supply, so its work is not affected by the external environment.

[0080] In a certain summer noon, the ambient temperature is 42℃, a four-wheel electric vehicle driven by ternary lithium-ion battery pack is out of power and enters parking space 1 for charging. A fast charging pile independent of the electric vehicle thermal management auxiliary system is arranged near parking space 1. When the electric vehicle communicates with the electric vehicle thermal management auxiliary system through the vehicle machine and requests auxiliary thermal management service, the electric vehicle thermal management auxiliary system detects the tire position and, combined with the vehicle model design information, infers the normal projection area of the battery pack on parking space 1. When the auxiliary thermal management service is started, it is found through online real-time communication with the electric vehicle that the temperature of the battery pack is 45℃, so the refrigeration and heating unit 3 works in the refrigeration mode, the pump 5 is started, and the valves 9 corresponding to all the nozzles 2 in the normal projection area of the battery pack on parking space 1 are opened, low-temperature liquid is sprayed to the corresponding area of the chassis, and the spraying is stopped until the temperature of the battery pack is less than 40℃. In this way, the temperature of the battery pack is quickly reduced to a reasonable range and maintained, ensuring that the battery quickly meets the temperature conditions required for fast charging, so that the battery pack can safely, stably and efficiently perform fast charging.

[0081] In a certain winter morning, the ambient temperature is 1℃, a four-wheel electric vehicle driven by lithium iron lithium-ion battery pack is parked on parking space 1 for one night. The owner wants to start the vehicle as soon as possible and drive away, so the auxiliary thermal management service is used. When the auxiliary thermal management service is started, it is found through online real-time communication with the electric vehicle that the temperature of the battery pack is 1℃, so the refrigeration and heating unit 3 works in the heating mode, the pump 5 is started, and the valves 9 corresponding to all the nozzles 2 in the normal projection area of the battery pack on parking space 1 are opened, high-temperature liquid is sprayed to the corresponding area of the chassis, and the spraying is stopped until the temperature of the battery pack is greater than 10℃. In this way, the temperature of the battery pack is quickly raised, the internal resistance of the battery is reduced, the discharge capacity of the battery is improved, and the need for the vehicle to drive as soon as possible is met.

[0082] The technical scheme of the thermal management auxiliary system and the use method thereof is proposed in the embodiment of the present application to meet the rapid use demand of the electric vehicle charging and long-time parking after the electric vehicle charging and long-time parking under the harsh weather conditions. The thermal management auxiliary system uses external functions and does not depend on the functions of the electric vehicle itself, overcoming the problem of insufficient charging and discharging capacity of the battery pack under harsh weather conditions; the refrigeration and heating unit 3 of the thermal management auxiliary system can be larger and can provide larger refrigeration and heating capacity than the air conditioning system of the electric vehicle itself, so it works quickly; the thermal management auxiliary system uses the pressure signal generated by the pressure sensor 11 arranged on the surface of the parking space 1 through the tire and obtains the vehicle model information through communication to identify the position of the battery pack in the horizontal direction, so as to selectively activate the liquid spraying function of the nozzles 2 directly below the battery pack, so it has the advantages of high precision, high energy efficiency and liquid recovery rate, and no adverse effects on the outside world.

Claims

1. A method for using an electric vehicle thermal management auxiliary system suitable for harsh weather conditions, for providing thermal management functions for a battery pack located above the chassis of an electric vehicle, characterized in that, the method is based on a thermal management auxiliary system for providing auxiliary thermal management for the charging process and post-parking start-up requirements of an electric vehicle; the thermal management auxiliary system comprises a parking space (1), a nozzle array, a refrigeration and heating unit (3), a liquid collecting tank (4), a pump (5) and a heat exchange chamber (6), and a surface pressure sensor array composed of a plurality of pressure sensors (11) and uniformly distributed on the surface of the parking space (1); the nozzle array is composed of a plurality of nozzles (2) and is uniformly distributed on the surface of the parking space (1); each nozzle (2) in the nozzle array is respectively communicated through a branch pipe (8) and a main pipe (7), and the main pipe (7) takes liquid from the heat exchange chamber (6) through the pump (5); a valve (9) is respectively arranged on the corresponding branch pipe (8) of each nozzle (2); the liquid collecting tank (4) is communicated with the heat exchange chamber (6) and is used to collect the liquid sprayed by the nozzle array and returned to the surface of the parking space (1) and make it return to the heat exchange chamber (6); the refrigeration and heating unit (3) is provided with a heat exchange pipe (31) immersed in the liquid in the heat exchange chamber (6) to cool or heat the liquid; the method is: when the electric vehicle is parked on the parking space (1) and issues a thermal management auxiliary system use requirement, the following steps are sequentially executed: Step S1, collect the pressure values obtained by each pressure sensor (11) in the pressure sensor array, and obtain the tire position distribution information of the electric vehicle from the pressure values; Step S2, obtain the vehicle model information of the electric vehicle by communicating with the electric vehicle, and combine the tire position distribution information obtained in step S1 to calculate the projection area of the battery pack on the parking space (1), wherein the vehicle model information includes the relative position information of the battery pack and each tire in the horizontal direction; Step S3, find all nozzles (2) within the orthographic projection area of the battery pack on the parking space (1); Step S4, communicate with the electric vehicle online in real time to obtain the temperature of the battery pack: if the temperature of the battery pack is less than or equal to a first temperature threshold, make the refrigeration and heating unit (3) work in a heating mode, start the pump (5) and open the valves (9) corresponding to all nozzles (2) in step S3, spray liquid to the corresponding area of the chassis until the temperature of the battery pack is greater than the first temperature threshold; if the temperature of the battery pack is greater than or equal to a second temperature threshold, make the refrigeration and heating unit (3) work in a refrigeration mode, start the pump (5) and open the valves (9) corresponding to all nozzles (2) in step S3, spray liquid to the corresponding area of the chassis until the temperature of the battery pack is less than the second temperature threshold; the first temperature threshold is less than the second temperature threshold; In step S2, the electric vehicle is parked on the parking space in the specified vehicle head direction, otherwise the vehicle tells the thermal management auxiliary system that its orientation is opposite to the specified direction to determine the coordinate information of the edge of the battery pack; Step S1 specifically includes the following sub-steps: Sub-step S1.1, placing the pressure sensors (11) with pressure values greater than the pressure threshold value Pc into a data set, each element in the data set corresponding to a pressure value of a pressure sensor (11) and its position coordinates; Sub-step S1.2, randomly selecting an element from the data set, respectively calculating the distance between the element and all the remaining elements, and counting the elements with distance values less than the distance threshold value Lc together with the element into the same element group, wherein the distance between any two elements is the distance between the corresponding position coordinates of the two elements; Sub-step S1.3, deleting the elements that have been counted into the element groups from the data set; Sub-step S1.4, repeating sub-steps S1.2 to S1.3 until the number of elements in the data set is 0; Sub-step S1.5, sequentially calculating the center coordinates of each element group, i.e. obtaining the position coordinates of each tire of the electric vehicle, wherein the center coordinates of any element group are the geometric center of the position coordinates corresponding to all elements in the element group.

2. The method of using a severe weather capable electric vehicle thermal management assist system of claim 1, wherein, The heat exchange chamber (6) is located below the liquid collecting tank (4) so that the liquid collected by the liquid collecting tank (4) naturally flows into the heat exchange chamber (6) under the action of gravity.

3. The method of using a severe weather capable electric vehicle thermal management assist system of claim 1, wherein, The part where the liquid collecting tank (4) communicates with the heat exchange chamber (6) is provided with a filter screen (10) to filter the solid impurities that may be contained in the liquid delivered by the liquid collecting tank (4).

4. The method of using a severe weather capable electric vehicle thermal management assist system of claim 1, wherein, The surface of the parking space (1) has a slope, and the liquid collecting tank (4) is arranged at the lowest part of the surface of the parking space (1) so that the liquid on the surface of the parking space (1) naturally flows into the liquid collecting tank (4) under the action of gravity.

5. The method of using a severe weather capable electric vehicle thermal management assist system of claim 1, wherein, The liquid sprayed by the nozzle array is water or an aqueous solution.

6. The method of using a severe weather capable electric vehicle thermal management assist system of claim 5, wherein, When the liquid sprayed by the nozzle array is an aqueous solution, the solute includes inorganic salts and corrosion inhibitors, wherein the inorganic salts are used to lower the freezing point of water, and the corrosion inhibitors are used to slow down the corrosion effect of inorganic salts on the chassis of the electric vehicle.

7. The method of using a severe weather capable electric vehicle thermal management assist system of claim 1, wherein, The thermal management auxiliary system further comprises a controller, which is electrically connected with the pressure sensor array, the refrigeration and heating unit (3), the pump (5) and the valves (9) arranged on all branch pipes (8), and can communicate with the electric vehicle.

Images