Electric vehicle thermal management auxiliary system suitable for atrocious weather conditions and using method

Abstract

The invention provides an electric vehicle thermal management auxiliary system suitable for atrocious weather conditions. The electric vehicle thermal management auxiliary system comprises a parking space (1), a nozzle array, a refrigerating and heating unit (3), a liquid collecting tank (4), a pump (5) and a heat exchange chamber (6). If the temperature of the battery pack is smaller than or equal to a first temperature threshold value or larger than or equal to a second temperature threshold value, a refrigerating and heating unit (3) works in a heating mode or a refrigerating mode, a pump (5) is started, a valve (9) corresponding to a nozzle (2) is opened, liquid is sprayed to a corresponding area of a chassis, and the temperature of the battery pack is controlled to be lower than the first temperature threshold value or larger than or equal to the second temperature threshold value. The temperature of the battery pack is larger than the first temperature threshold value or smaller than the second temperature threshold value. In addition, the position of the wheel can be obtained through the pressure sensor (11), the position of the battery pack in the horizontal direction is recognized, the liquid spraying function of the nozzle (2) under the battery pack is selectively activated, and therefore the device has the advantages of being high in precision, energy efficiency and liquid recovery rate and free of adverse effects on the outside world.

Description

Technical Field

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

[0002] At present, electric vehicles are mainly powered by lithium-ion battery packs located on their chassis. The charging and discharging of lithium-ion battery packs need to be carried out in a suitable temperature environment. Although electric vehicles have certain thermal management functions during operation, when electric vehicles are charged or parked under high or low ambient temperatures, their own thermal management functions have great limitations due to limited cooling and heating capabilities, time-consuming and power-consuming factors. Therefore, it is necessary to develop additional electric vehicle battery thermal management auxiliary systems to overcome the limitations of electric vehicles' own thermal management functions under harsh climatic conditions such as low or high ambient temperatures. Summary of the invention

[0003] The main purpose of the present invention is to provide an electric vehicle thermal management auxiliary system and a method of use suitable for severe weather conditions, aiming to solve the technical problem of limited thermal management function of electric vehicles themselves in environments with high or low external temperatures, thereby providing auxiliary thermal management for the charging process of electric vehicles and the starting needs after parking.

[0004] To achieve the above object, the present invention provides an electric vehicle thermal management auxiliary system suitable for severe weather conditions, which is used to provide thermal management functions for a battery pack located above the chassis of the electric vehicle, and the thermal management auxiliary system includes a parking space, a nozzle array, a cooling and heating unit, a sump, a pump and a heat exchange chamber;

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

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

[0007] Each branch pipe corresponding to each nozzle is provided with a valve;

[0008] The liquid collecting tank is in communication with the heat exchange chamber and is used to collect the liquid that flows back to the parking space surface after being sprayed out by the nozzle array and return it to the heat exchange chamber;

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

[0010] Optionally, in the above-mentioned 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, in the above-mentioned electric vehicle thermal management auxiliary system suitable for severe weather conditions, a filter is provided at the portion where the liquid collecting tank is connected to the heat exchange chamber to filter solid debris that may be contained in the liquid sent from the liquid collecting tank.

[0012] Optionally, in the above-mentioned electric vehicle thermal management auxiliary system suitable for severe weather conditions, the parking space surface has a slope, and the liquid collecting tank is arranged at the lowest point of the parking space surface, so that the liquid on the parking space surface naturally flows into the liquid collecting tank under the action of gravity.

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

[0014] Furthermore, when the liquid sprayed from the nozzle array is an aqueous solution, the solute includes an inorganic salt and a corrosion inhibitor, wherein the inorganic salt is used to lower the freezing point of water, and the corrosion inhibitor is used to mitigate the corrosion effect of the inorganic salt on the chassis of the electric vehicle.

[0015] Optionally, the above-mentioned electric vehicle thermal management assistance system suitable for severe weather conditions further includes a surface pressure sensor array composed of a plurality of pressure sensors and evenly distributed in the parking space.

[0016] Optionally, the above-mentioned electric vehicle thermal management auxiliary system suitable for severe weather conditions also includes a controller, which is electrically connected to the pressure sensor array, the cooling and heating unit, the pump and the valves provided on all branch pipes, and can communicate with the electric vehicle.

[0017] In addition, to achieve the above-mentioned purpose, the present invention also provides a method for using the electric vehicle thermal management auxiliary system applicable to severe weather conditions as described in any of the above items. When the electric vehicle is parked in a parking space and a demand for using the thermal management auxiliary system is issued, the following steps are performed in sequence:

[0018] Step S1, collecting the pressure values ​​obtained by each pressure sensor in the pressure sensor array, and thereby obtaining tire position distribution information of the electric vehicle;

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

[0020] Step S3, finding all 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 cooling 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, and liquid is sprayed 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, the cooling and heating unit is operated in the cooling mode, the pump is started and the valves corresponding to all the nozzles in step S3 are opened, and liquid is sprayed to the corresponding area of ​​the chassis until the temperature of the battery pack is less than the second temperature threshold; the above first temperature threshold is less than the second temperature threshold.

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

[0023] Sub-step S1.1, placing pressure sensors whose pressure values ​​are greater than the pressure threshold Pc in a data set, wherein each element in the data set corresponds to a pressure value and position coordinates of a pressure sensor;

[0024] 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 whose distance values ​​to the element are less than the distance threshold 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;

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

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

[0027] Sub-step S1.5, calculating the center coordinates of each element group in turn, that is, obtaining the position coordinates of each tire of the electric vehicle, wherein the center coordinate of any element group is the geometric center of the position coordinates corresponding to all elements in the element group.

[0028] The beneficial effects of the technical solution of the present invention are introduced below in combination with the principle thereof.

[0029] First, imagine two major usage scenarios for electric vehicles.

[0030] Scenario 1: After driving in a high temperature environment for a period of time, the electric car is running low on power and is parked outdoors for charging. At the beginning of charging, the temperature of the battery pack is very high and needs to be lowered to a suitable temperature before normal charging can be performed. At this time, if the electric car's own cooling function is used to cool the battery pack, its cooling power is limited; secondly, the electric car itself has very little power left and cannot bear the power required for cooling. The charging process is fast charging, and the battery pack generates a lot of heat. At this time, if the electric car's own cooling function is used to cool the battery pack, its cooling power is limited; secondly, it will inevitably reduce the charging current that the battery pack can share, reducing its own charging rate.

[0031] Scenario 2: After an electric car has been parked for a long time in a cold outdoor environment, the owner needs to drive away. Since the battery pack is in a low temperature state, it cannot provide enough discharge power for the electric car in a short time to meet its driving needs.

[0032] Therefore, it is necessary to provide electric vehicles with thermal management auxiliary services with external functions in parking spaces to meet the needs of fast charging of vehicles under severe climatic conditions such as excessively high or low ambient temperatures and fast starting after long-term parking.

[0033] The technical means of the present invention for providing auxiliary thermal management for electric vehicles are as follows: liquid is stored in a heat exchange chamber, the liquid is pumped to a main pipe, and then the valve of the corresponding branch pipe is opened as needed to allow the liquid to be sprayed upward from the corresponding nozzle along the branch pipe, thereby spraying onto the chassis below the battery pack area of ​​the electric vehicle; the high-speed flowing liquid flushes the chassis, which can bring about a large convective heat transfer effect, so the corresponding area of ​​the chassis can be quickly cooled or heated, and the battery pack can be further cooled or heated by means of heat conduction between the chassis and the battery pack; after the liquid flushes the chassis, it is reflected back and falls onto the surface of the parking space with a slope, is collected by a liquid collecting tank at the lowest point of the parking space surface, and finally flows back to the heat exchange chamber, and is recycled after heat exchange with the heat exchange tube of the cooling and heating unit; and whether the cooling and heating unit works in cooling mode or heating mode is determined by means of real-time communication between the thermal management auxiliary system and the electric vehicle: if it is known that the temperature of the battery pack is less than or equal to the first temperature threshold, it works in heating mode; if it is known that the temperature of the battery pack is greater than or equal to the second temperature threshold, it works in cooling mode.

[0034] The liquid used as the heat exchange medium is water or aqueous solution. If there are a certain number of days with a temperature below 0°C in the local area, an aqueous solution is used. 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 electric vehicles.

[0035] In order to improve the operating accuracy and efficiency of the system, the liquid needs to be sprayed exactly to the chassis area directly below the battery pack. Otherwise, if the liquid is sprayed to other areas of the chassis, there will be waste; even if the liquid is sprayed to areas outside the chassis, it may eventually spray onto the vehicle body and surrounding pedestrians and objects, which will not only cause waste and make it difficult to recycle the liquid, but also bring adverse effects. To this end, it is necessary to obtain the actual parking position of the electric vehicle, and read the relative distance between the tire and the battery pack in two orthogonal directions on the horizontal plane from the vehicle model information, so as to accurately calculate the position of the battery pack.

[0036] Among the currently known technical means, the parking location information of electric vehicles can be identified by means such as laser or image recognition, but these means are easily affected by external interference such as rain, fog, and sunlight, and surface dirt such as dust on the vehicle itself and in the environment will also cause certain interference to the identification. In the technical solution of the present invention, the parking position information of the electric vehicle is obtained by knowing the tire position of the electric vehicle: if the pressure value measured by the pressure sensor at certain positions on the parking space surface is greater than the pressure threshold Pc, it means that there is pressure generated by the tire at these positions, so the pressure sensors with pressure values ​​greater than the pressure threshold Pc are placed in the data set; further, considering that there is a gap between the tire and each contact surface of the parking space surface, an element is randomly selected in the data set, and the distance between the element and all remaining elements is calculated respectively, and the elements with a distance value less than the distance threshold Lc from the element are counted together with the element in the same element group, and it is considered that the pressure sensors in the same element group correspond to the same tire; then the elements that have been counted in the element group are deleted from the data set, and the steps of grouping and deleting the elements 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 position coordinates of each tire of the electric vehicle are obtained.

[0037] Therefore, the present invention proposes a technical solution for a thermal management auxiliary system and its use method to meet the needs of rapid activation of electric vehicles after charging and long-term parking under harsh weather conditions such as high or low temperatures. The thermal management auxiliary system uses external functions and does not rely on the electric vehicle's own functions, thus overcoming the problem of insufficient charging and discharging capacity of the battery pack under harsh weather conditions; the cooling and heating unit of the thermal management auxiliary system can be made larger and can provide a higher-power cooling and heating capacity than the electric vehicle's own air-conditioning system, so it takes effect quickly; the thermal management auxiliary system uses the pressure signal generated by the pressure sensor arranged on the surface of the parking space by the tire, and obtains the vehicle model information through communication, and identifies the horizontal position of the battery pack, thereby selectively activating the spray 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 THE DRAWINGS

[0038] Figure 1Schematic diagram of the structure of the electric vehicle thermal management auxiliary system suitable for severe weather conditions in an embodiment of the present invention.

[0039] Figure 2 The figure is a schematic diagram of the structure of the liquid delivery network in the electric vehicle thermal management auxiliary system suitable for severe weather conditions in an embodiment of the present invention.

[0040] Figure 3 The present invention is a flowchart of a method for using a thermal management auxiliary system for an electric vehicle suitable for severe weather conditions according to an embodiment of the present invention.

[0041] Figure 4 for Figure 3 Flow chart of step S1 in FIG.

[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, 11-pressure sensor, 31-heat exchange tube. DETAILED DESCRIPTION

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

[0044] like Figure 1 and Figure 2 As shown, the present invention provides an electric vehicle thermal management auxiliary system suitable for severe weather conditions, which is used to provide thermal management functions for a battery pack located above the chassis of an electric vehicle, and is characterized in that the thermal management auxiliary system includes a parking space 1, a nozzle array, a cooling 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 evenly distributed on the surface of the parking space 1;

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

[0047] Each branch pipe 8 corresponding to each nozzle 2 is provided with a valve 9;

[0048] The liquid collecting tank 4 is connected to the heat exchange chamber 6 and is used to collect the liquid that flows back to the surface of the parking space 1 after being sprayed out by the nozzle array and return it to the heat exchange chamber 6;

[0049] The cooling and heating unit 3 is provided with a heat exchange tube 31 , and the heat exchange tube 31 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 liquid collecting tank 4, so that the liquid collected by the liquid collecting tank 4 flows naturally into the heat exchange chamber 6 under the action of gravity. Furthermore, the liquid collecting tank 4 has a certain slope, wherein the end of the liquid collecting tank 4 connected to the heat exchange chamber 6 is the lowest position of the liquid collecting tank 4, thereby making it more convenient for the liquid collected by the liquid collecting tank 4 to flow naturally into the heat exchange chamber 6 under the action of gravity.

[0051] Preferably, a filter screen 10 is provided at the portion where the liquid collecting tank 4 communicates with the heat exchange chamber 6 to filter out solid impurities that may be contained in the liquid sent from the liquid collecting tank 4 .

[0052] Preferably, the surface of the parking space 1 has a slope, and the liquid collecting tank 4 is arranged at the lowest point 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.

[0053] In one embodiment, the surface of the parking space 1 is low in the middle and high on both sides, and the liquid collecting tank 4 is located in the center of the surface of the parking space 1; in another embodiment, the surface of the parking space 1 is high in the middle and low on both sides, and the two liquid collecting tanks 4 are respectively located at the two side edges of the surface of the parking space 1, and are connected to the heat exchange chamber 6 after merging 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 an inorganic salt and a corrosion inhibitor, wherein the inorganic salt is used to lower the freezing point of water, and the corrosion inhibitor is used to slow down the corrosion effect of the inorganic salt on the chassis of the electric vehicle. Among them, the inorganic salt can be selected from sodium chloride, and the main component of the corrosion inhibitor can include any one of molybdate, tungstate and azole substances.

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

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

[0057] Figure 1 The nozzles 2 and pressure sensors 11 in the figure are for illustration only and their numbers do not represent the actual number.

[0058] Figure 2 The figure only shows the liquid delivery network. Due to the limited space, it is impossible to draw all the nozzles 2 and their corresponding branches 8 and valves 9, so they are replaced by ellipsis “…”.

[0059] like Figure 3As shown, the method for using the thermal management auxiliary system of the electric vehicle applicable to the above-mentioned severe weather conditions is that when the electric vehicle is parked in the parking space 1 and a demand for using the thermal management auxiliary system is issued, the following steps are performed in sequence:

[0060] Step S1, collecting the pressure values ​​obtained by each pressure sensor 11 in the pressure sensor array, and thereby obtaining tire position distribution information of the electric vehicle;

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

[0062] Step S3, finding 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, the cooling and heating unit 3 is operated in the heating mode, the pump 5 is started and the valves 9 corresponding to all the nozzles 2 in step S3 are opened, and liquid is sprayed 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, the cooling and heating unit 3 is operated in the cooling mode, the pump 5 is started and the valves 9 corresponding to all the nozzles 2 in step S3 are opened, and liquid is sprayed to the corresponding area of ​​the chassis until the temperature of the battery pack is less than the second temperature threshold; the above first temperature threshold is less than the second temperature threshold.

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

[0065] Sub-step S1.1, placing the pressure sensor 11 whose pressure value is greater than the pressure threshold Pc in a data set, wherein 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 whose distance values ​​to the element are less than the distance threshold 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;

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

[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, calculating the center coordinates of each element group in turn, that is, obtaining the position coordinates of each tire of the electric vehicle, wherein the center coordinate of any element group is 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 data structure in the form of a dictionary: {No:(x,y)}, where 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. 1 ,y 1 ) and (x 2 ,y 2 ), then the distance between the two is:

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

[0072] The abscissa of the center coordinate of an element group is the arithmetic mean of the abscissas corresponding to all elements in the element group; the ordinate of the center coordinate of an element group is the arithmetic mean of the ordinates corresponding to all elements in the element group.

[0073] On the basis of obtaining the coordinates of the positions of the tires of the electric vehicle, the coordinate information of the edge of the battery pack is calculated in combination with the design size information of the model to which the electric vehicle belongs. It should be pointed out that the technical solution of the present invention assumes that the electric vehicle is parked in parking space 1 according to the specified front direction of the vehicle. Usually, parking space 1 has a sign or clear information to allow the owner to park in accordance with the regulations. If the direction of the electric vehicle is opposite to the specified direction, it is necessary to communicate with the thermal management auxiliary system with the help of the vehicle computer to inform it that the direction is opposite to the specified direction, so that the thermal management auxiliary system can accurately determine the coordinate information of the edge of the battery pack.

[0074] For example, in one embodiment, the coordinates of the four tires of an electric vehicle parked in accordance with the specification are obtained as follows: 1 ,b 1 )、(a 2 ,b 2 )、(a 3 ,b 3 )、(a 4 ,b 4 ), where b 1 and b 2 Approximately equal, b 3 and b 4Approximately equal. According to the coordinate setting rules on parking space 1, the coordinates of the two front wheels are (a 1 ,b 1 ) and (a 2 ,b 2 ), the coordinates of the two rear wheels are (a 3 ,b 3 ) and (a 4 ,b 4 ). By consulting the model information of the electric vehicle, it is known that the orthographic projection of the battery pack is a rectangle, and there is spacing information between its four vertices and the four tire coordinates on two orthogonal coordinate axes in the horizontal direction, based on which the coordinate information of the edge of the battery pack can be obtained. Since the controller (not shown in the attached figure) also stores the nozzle 2 number and coordinate information on the surface of the parking space 1 in advance, all nozzles 2 within the orthographic projection area of ​​the battery pack on the parking space 1 are found on this basis and the valves 9 corresponding to the relevant nozzles 2 are activated to make these nozzles 2 spray liquid.

[0075] On the contrary, in another embodiment, the front direction of the electric vehicle in parking space 1 is opposite to the default standard direction, and the electric vehicle informs the thermal management auxiliary system through the vehicle computer. In this case, it is necessary to replace the judgment rules of the front and rear wheels based on the default rules.

[0076] Preferably, considering the phenomenon of liquid evaporation, the electric vehicle thermal management auxiliary system further includes a liquid storage tank connected to the heat exchange chamber 6 and located above the heat exchange chamber 6, a liquid level sensor is provided in the heat exchange chamber 6, a valve 9 is provided at the connection between the liquid storage tank and the heat exchange chamber 6, and both the liquid level sensor and the valve 9 are electrically connected to 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 liquid in the liquid storage tank into the heat exchange chamber 6, and the valve 9 is closed only after the liquid level in the heat exchange chamber 6 is greater than or equal to the liquid level threshold.

[0077] Example

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

[0079] In this embodiment, the liquid sprayed by the nozzle array is water, the first temperature threshold is 10°C, the second temperature threshold is 40°C, 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 operation is not affected by the external environment.

[0080] At noon in midsummer, the ambient temperature was 42°C. A four-wheeled electric vehicle driven by a ternary lithium-ion battery pack ran out of power and drove into parking space 1 to charge. A fast charging pile independent of the electric vehicle thermal management auxiliary system is provided near parking space 1. When the electric vehicle communicates with the electric vehicle thermal management auxiliary system through the vehicle computer and requests auxiliary thermal management service, the electric vehicle thermal management auxiliary system detects its tire position and infers the positive projection area of ​​the battery pack on parking space 1 in combination with its vehicle model design information. When the auxiliary thermal management service is just started, it is found through online real-time communication with the electric vehicle that the temperature of the battery pack is 45°C, so the cooling and heating unit 3 is operated in the cooling mode, the pump 5 is started and the valves 9 corresponding to all nozzles 2 in the positive projection area of ​​the battery pack on parking space 1 are opened, and the low-temperature liquid is sprayed to the corresponding area of ​​the chassis until the temperature of the battery pack is less than 40°C before the spraying is stopped. 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 the fast charging process, so that the battery pack can be quickly charged safely, stably and efficiently.

[0081] On a cold winter morning, the ambient temperature was 1°C, and a four-wheel electric vehicle driven by a lithium iron phosphate lithium-ion battery pack had been parked in parking space 1 for a night. The owner wanted to start the vehicle and leave as soon as possible, so he used the auxiliary thermal management service. When the auxiliary thermal management service was just started, it was found through online real-time communication with the electric vehicle that the temperature of the battery pack was 1°C, so the cooling and heating unit 3 was operated in heating mode, the pump 5 was started and the valves 9 corresponding to all nozzles 2 in the orthographic projection area of ​​the battery pack on the parking space 1 were opened, and the high-temperature liquid was sprayed to the corresponding area of ​​the chassis until the temperature of the battery pack was greater than 10°C. The spraying was stopped. In this way, the temperature of the battery pack was rapidly increased, the internal resistance of the battery was reduced, and the battery discharge capacity was improved to meet the vehicle's need to drive as quickly as possible.

[0082] In the embodiment of the present invention, a technical solution of a thermal management auxiliary system and its use method is proposed to meet the demand for rapid activation of electric vehicles after charging and long-term parking under adverse weather conditions such as high or low temperatures. The thermal management auxiliary system uses external functions and does not rely on the functions of the electric vehicle itself, thus overcoming the problem of insufficient charging and discharging capacity of the battery pack under adverse weather conditions; the cooling and heating unit 3 of the thermal management auxiliary system can be made larger and can provide a higher power cooling and heating capacity than the air conditioning system of the electric vehicle itself, so it takes effect 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 by the tire, and obtains the vehicle model information through communication, identifies the horizontal position of the battery pack, and selectively activates the liquid spraying function of the nozzle 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. An electric vehicle thermal management auxiliary system suitable for severe weather conditions, used to provide thermal management functions for a battery pack located above the chassis of an 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); The nozzle array is composed of a plurality of nozzles (2) and is evenly distributed on the surface of the parking space (1); Each nozzle (2) in the nozzle array is connected to a main pipe (7) through a branch pipe (8), and the main pipe (7) draws liquid from the heat exchange chamber (6) through a pump (5); Each branch pipe (8) corresponding to each nozzle (2) is provided with a valve (9); The liquid collecting tank (4) is in communication with the heat exchange chamber (6) and is used to collect the liquid that flows back to the surface of the parking space (1) after being sprayed out by the nozzle array and return it to the heat exchange chamber (6); The refrigeration and heating unit (3) is provided with a heat exchange tube (31), and the heat exchange tube (31) is immersed in the liquid in the heat exchange chamber (6) to cool or heat the liquid.

2. The electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 1, characterized in that: The heat exchange chamber (6) is located below the liquid collecting tank (4) so ​​that the liquid collected by the liquid collecting tank (4) can flow naturally into the heat exchange chamber (6) under the action of gravity.

3. The electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 1, characterized in that: A filter screen (10) is provided at the portion where the liquid collecting tank (4) communicates with the heat exchange chamber (6) to filter solid impurities that may be contained in the liquid sent from the liquid collecting tank (4).

4. The electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 1, characterized in that: The surface of the parking space (1) has a slope, and the liquid collecting tank (4) is arranged at the lowest point 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 electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 1, characterized in that: The liquid sprayed by the nozzle array is water or an aqueous solution.

6. The electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 5, characterized in that: When the liquid sprayed from the nozzle array is an aqueous solution, the solute includes an inorganic salt and a corrosion inhibitor, wherein the inorganic salt is used to lower the freezing point of water, and the corrosion inhibitor is used to mitigate the corrosion effect of the inorganic salt on the chassis of the electric vehicle.

7. The electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 1, characterized in that: The thermal management auxiliary system further comprises a surface pressure sensor array consisting of a plurality of pressure sensors (11) and evenly distributed on the parking space (1).

8. The electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 1 or 7, characterized in that: The thermal management auxiliary system also includes a controller, which is electrically connected to the pressure sensor array, the cooling and heating unit (3), the pump (5) and the valves (9) provided on all branch pipes (8), and is capable of communicating with the electric vehicle.

9. A method for using the electric vehicle thermal management auxiliary system for severe weather conditions as claimed in any one of claims 1 to 8, characterized in that: When the electric vehicle is parked in the parking space (1) and a request is made to use the thermal management auxiliary system, the following steps are performed in sequence: Step S1, collecting the pressure values ​​obtained by each pressure sensor (11) in the pressure sensor array, and thereby obtaining tire position distribution information of the electric vehicle; Step S2, obtaining the vehicle model information of the electric vehicle by communicating with the electric vehicle, and calculating the projection area of ​​the battery pack of the electric vehicle on the parking space (1) in combination with the tire position distribution information obtained in step S1, wherein the vehicle model information includes the relative position information of the battery pack and each tire in the horizontal direction; Step S3, finding all nozzles (2) within the orthographic projection area of ​​the battery pack on the parking space (1); 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 cooling and heating unit (3) is operated in the heating mode, the pump (5) is started and the valves (9) corresponding to all the nozzles (2) in step S3 are opened, and liquid is sprayed 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, the cooling and heating unit (3) is operated in the cooling mode, the pump (5) is started and the valves (9) corresponding to all the nozzles (2) in step S3 are opened, and liquid is sprayed to the corresponding area of ​​the chassis until the temperature of the battery pack is less than the second temperature threshold; the above first temperature threshold is less than the second temperature threshold.

10. The method for using the electric vehicle thermal management auxiliary system suitable for severe weather conditions according to claim 9, characterized in that: Step S1 specifically includes the following sub-steps: Sub-step S1.1, placing a pressure sensor (11) having a pressure value greater than a pressure threshold value Pc in a data set, wherein each element in the data set corresponds to a pressure value and position coordinates of a pressure sensor (11); 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 whose distance values ​​to the element are less than the distance threshold 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 in the element group from the data set; Sub-step S1.4, repeat sub-steps S1.2 to S1.3 until the number of elements in the data set is 0; Sub-step S1.5, calculating the center coordinates of each element group in turn, that is, obtaining the position coordinates of each tire of the electric vehicle, wherein the center coordinate of any element group is the geometric center of the position coordinates corresponding to all elements in the element group.

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