Electric vehicle battery heat dissipation method and system

Abstract

The present invention relates to the technical field of heat dissipation of electric vehicle batteries, and in particular to a method and system for heat dissipation of electric vehicle batteries. The present invention utilizes a battery simulation model to obtain a battery heat dissipation demand curve and a relationship curve between cockpit temperature and air conditioning power and integrates them, then determines the relationship curve between the outflow temperature, outflow velocity, time, and battery temperature of a liquid coolant, and finally calculates a control strategy for minimizing the energy consumption of cooling a battery liquid coolant by an air conditioner and ensuring that the battery temperature is within a specific range through a Markov decision model through reinforcement learning. The present invention can ensure that the energy consumption of cooling a battery by an air conditioner is reduced when the battery is in a normal temperature range.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle battery heat dissipation, and in particular to an electric vehicle battery heat dissipation method and system. Background Art

[0002] The rapid development of electric vehicles has put forward higher requirements for battery thermal management. In current technologies, battery thermal management systems mainly face the following challenges: the heat generated by the battery during charging and discharging is difficult to manage effectively; in addition, the energy distribution between battery thermal management and the cabin temperature control system is uneven, resulting in low energy utilization efficiency, affecting battery life and vehicle range.

[0003] In addition, the operating temperature range of the battery is also an important factor affecting battery performance and safety. When the battery operates at a high temperature for a long time, gas may be released inside, affecting the battery's service life. If the battery temperature exceeds 60°C, the chemical properties of lithium ions may become unstable, and accidents may occur in serious cases. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a method and system for heat dissipation of an electric vehicle battery, so as to achieve reasonable management of the temperature of the electric vehicle battery.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for dissipating heat from an electric vehicle battery, comprising:

[0007] Construct a battery simulation model based on the battery pack structure and battery parameters of electric vehicles;

[0008] Based on the constructed battery simulation model, the battery heat dissipation demand curve is calculated under different ambient temperatures and vehicle speeds according to the ambient temperature and electric vehicle related parameters;

[0009] Construct a cockpit heat load model, and obtain the relationship curve between cockpit temperature and air conditioning power based on the cockpit heat load model;

[0010] According to the air conditioning system cooling the battery liquid coolant, the air conditioning power of the air conditioning system cooling the battery liquid coolant is added to the relationship curve between the cockpit temperature and the air conditioning power, and the battery heat dissipation demand curve is adjusted based on the adjusted relationship curve between the cockpit temperature and the air conditioning power;

[0011] Based on the battery pack structure and the adjusted battery heat dissipation demand curve, a relationship curve among the outflow temperature, outflow velocity, time and battery temperature of the liquid coolant is obtained;

[0012] Collect actual driving data of electric vehicles, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the relationship curve between the outflow temperature of the liquid coolant, the outflow flow rate, time, and battery temperature, minimize the energy consumption of the air conditioner to cool the battery liquid coolant and ensure that the battery temperature is within a specific range, derive the control strategy of the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the inlet flow rate over time;

[0013] According to the obtained power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time, the relevant parameters of the electric vehicle battery heat dissipation are adjusted.

[0014] As an implementable method, the battery simulation model constructed based on the battery simulation model calculates the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds according to the ambient temperature and electric vehicle related parameters, including:

[0015] The load power of the power battery is calculated by the electric vehicle driving efficiency, electric vehicle mass, air resistance coefficient, windward area, rolling damping coefficient and vehicle speed;

[0016] Calculate the battery operating current by calculating the load power of the power battery, the battery discharge efficiency, the motor drive efficiency and the battery voltage;

[0017] The battery heat generation power is calculated by the obtained battery operating current, battery equivalent internal resistance and battery temperature;

[0018] The battery heat generation is calculated by the battery heat generation power, and the ambient heat dissipation is calculated by the battery specific heat capacity, the total mass of the battery, and the difference between the battery temperature and the ambient temperature;

[0019] The heat dissipation power is obtained according to the heat generated by the battery and the heat dissipation of the environment;

[0020] Different ambient temperatures and vehicle speeds are used to obtain different heat dissipation powers and the battery heat dissipation demand curve.

[0021] As an implementable method, the relationship curve between cockpit temperature and air conditioning power obtained according to the cockpit heat load model includes:

[0022] The cockpit heat load model is constructed by the energy loss caused by the thermal insulation performance of the cockpit, the heat load generated by the passengers in the cockpit and the heat transferred by the windows;

[0023] According to the cockpit heat load model, the required air conditioning power and the energy efficiency ratio of the air conditioning, the relationship curve between the cockpit temperature and the air conditioning power is obtained.

[0024] As an implementable method, cooling the battery liquid coolant according to the air conditioning system, adding the air conditioning power of the air conditioning system for cooling the battery liquid coolant to the relationship curve between the cockpit temperature and the air conditioning power, and adjusting the battery heat dissipation demand curve of the air conditioning system power includes:

[0025] The required air conditioning power and the heat dissipation power are summed up to obtain the total air conditioning power, and a curve of the relationship between the adjusted cockpit temperature and the air conditioning power is formed;

[0026] The total air-conditioning power of the adjusted cockpit temperature-air-conditioning power relationship curve is added to the load power, and then the battery cooling demand is recalculated to obtain the adjusted battery cooling demand curve.

[0027] As an implementable method, the actual driving data of the electric vehicle is collected, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the outflow temperature of the liquid coolant, the outflow flow rate, time, and the relationship curve of the battery temperature, the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time are obtained, while minimizing the energy consumption of the air conditioner to cool the battery liquid coolant. The control strategy includes:

[0028] Build a Markov decision model:

[0029] The battery temperature, cabin temperature, ambient temperature, vehicle speed, and acceleration are defined as the state set of the MDP;

[0030] Define a set of control actions, including power regulation of the air conditioner to cool the battery liquid coolant, liquid coolant outflow temperature control, and inlet flow rate adjustment;

[0031] Design a reward function to quantify the energy consumption of the air conditioner to cool the battery liquid coolant and ensure that the battery temperature is within a specific range after taking action in a specific state;

[0032] Using actual driving data, the optimal strategy is learned through a reinforcement learning algorithm, and iterative updates are performed to obtain the control strategy of the air conditioner's power to cool the battery liquid coolant, the liquid coolant's outflow temperature, and the inlet flow rate over time.

[0033] As an implementable embodiment, the liquid coolant is a nanofluid of γ-Al2O3 / deionized water with a mass concentration of 0.1%-2%.

[0034] As an implementable embodiment, the ensuring that the battery temperature is within a specific range is that the battery temperature is 20-45°C.

[0035] The present invention provides an electric vehicle battery heat dissipation system, including a battery simulation model module, a heat dissipation demand curve module, a cockpit temperature and air conditioning power relationship curve module, an adjustment module, a liquid coolant related parameter relationship curve module, a control strategy optimization module and a battery heat dissipation control module;

[0036] The battery simulation model module is used to construct a battery simulation model according to the battery pack structure and battery parameters of the electric vehicle;

[0037] The heat dissipation demand curve module is used to calculate the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds based on the constructed battery simulation model and according to the ambient temperature and electric vehicle related parameters;

[0038] The cockpit temperature and air conditioning power relationship curve module is used to construct a cockpit heat load model, and obtain a cockpit temperature and air conditioning power relationship curve according to the cockpit heat load model;

[0039] The adjustment module is used to cool the battery liquid coolant according to the air conditioning system, add the air conditioning power of the air conditioning system to cool the battery liquid coolant to the relationship curve between the cockpit temperature and the air conditioning power, and adjust the battery heat dissipation demand curve based on the adjusted relationship curve between the cockpit temperature and the air conditioning power;

[0040] The liquid coolant related parameter relationship curve module is used to obtain a relationship curve of the liquid coolant outflow temperature, outflow flow rate, time, and battery temperature based on the battery pack structure and the adjusted battery heat dissipation demand curve;

[0041] The control strategy optimization module is used to collect actual driving data of the electric vehicle, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the outflow temperature of the liquid coolant, the outflow flow rate, time, and the relationship curve of the battery temperature, the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time are obtained while minimizing the energy consumption of the air conditioner to cool the battery liquid coolant and ensuring that the battery temperature is within a specific range;

[0042] The battery heat dissipation control module is used to adjust the relevant parameters of the electric vehicle battery heat dissipation according to the obtained power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time.

[0043] The present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the electric vehicle battery heat dissipation method are implemented.

[0044] The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the electric vehicle battery heat dissipation method are implemented.

[0045] The beneficial effects of the present invention are as follows: the present invention constructs a method and system for cooling the battery of an electric vehicle, uses a battery simulation model to derive a battery cooling demand curve and a relationship curve between the cabin temperature and the air conditioning power and integrates them, then determines the relationship curve between the outflow temperature, outflow velocity, time, and battery temperature of the liquid coolant, and finally calculates a control strategy for minimizing the energy consumption of the air conditioner for cooling the battery liquid coolant and ensuring that the battery temperature is within a specific range through a Markov decision model through reinforcement learning. Through the present invention, it can be ensured that when the battery is in a normal temperature range, the energy consumption of the air conditioner for cooling the battery is reduced, the battery energy consumption is improved, and the vehicle mileage is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The present invention is a flow chart of a method for heat dissipation of an electric vehicle battery.

[0047] Figure 2 The present invention is a schematic diagram of an electric vehicle battery heat dissipation system. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below in conjunction with specific embodiments.

[0049] It should be noted that these embodiments are only used to illustrate the present invention rather than to limit the present invention. Simple improvements to the method based on the concept of the present invention all fall within the scope of protection claimed by the present invention.

[0050] See also Figure 1 , which is a method for cooling the battery of an electric vehicle, comprising:

[0051] S100: construct a battery simulation model according to the battery pack structure and battery parameters of the electric vehicle.

[0052] Analyze the structural design of the battery pack in detail, including the arrangement of battery cells, the layout of battery modules, and the overall size of the battery pack, etc. This step aims to determine the characteristics of heat distribution in the battery pack and provide basic data for subsequent thermal management.

[0053] Battery parameter measurement: Collect static parameters of individual battery cells, such as rated voltage, rated capacity, internal resistance, mass, thermal capacity, etc.

[0054] S200, based on the constructed battery simulation model, calculates the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds according to the ambient temperature and electric vehicle related parameters.

[0055] This embodiment provides a specific implementation process of the above steps:

[0056] The load power of the power battery is calculated by the electric vehicle driving efficiency, electric vehicle mass, air resistance coefficient, windward area, rolling damping coefficient and vehicle speed:

[0057]

[0058] Among them, is the driving efficiency of electric vehicles, m is the mass of electric vehicles, is the air resistance coefficient, A is the frontal area, f is the rolling damping coefficient, and u is the vehicle speed.

[0059] The battery operating current is calculated by calculating the load power of the power battery, battery discharge efficiency, motor drive efficiency and battery voltage:

[0060] in, is the battery discharge efficiency, is the motor driving efficiency, and U is the battery voltage.

[0061] The battery heat generation power is calculated by the obtained battery operating current, battery equivalent internal resistance and battery temperature:

[0062]

[0063] Where R is the equivalent internal resistance of the battery, T is the battery temperature, is the entropy thermal coefficient.

[0064] The battery heat generation Q is calculated by the battery heat generation power, and the ambient heat dissipation is calculated by the battery specific heat capacity, the total mass of the battery, and the difference between the battery temperature and the ambient temperature:

[0065]

[0066] Where c is the specific heat capacity of the battery, M is the total mass of the battery, is the difference between the battery temperature and the ambient temperature.

[0067] According to the battery heat Q and environmental heat Q m Get the heat dissipation power:

[0068]

[0069] Wherein, t is the heat dissipation time.

[0070] Different ambient temperatures and vehicle speeds can be used to obtain different heat dissipation powers and the battery heat dissipation demand curve. By simulating the battery operating state under different ambient temperatures and vehicle speeds, a series of heat dissipation power values ​​can be calculated to form a heat dissipation demand curve. This curve can be used to guide the design of the electric vehicle's heat dissipation system to ensure that the battery temperature is within the appropriate range.

[0071] S300: construct a cockpit heat load model, and obtain a relationship curve between cockpit temperature and air conditioning power according to the cockpit heat load model.

[0072] This embodiment provides a specific implementation process of the above steps:

[0073] The cockpit heat load model is constructed by the energy loss caused by the cockpit insulation performance, the heat load generated by the passengers in the cockpit, and the heat transfer heat of the windows:

[0074]

[0075] in, Energy loss due to cockpit insulation performance, is the number of passengers in the cockpit, is the sunlight intensity, is the temperature inside the cockpit, is the ambient temperature, The heat load generated for a single passenger, is the cockpit window area, is the heat transfer coefficient of the window; the heat load generated by a single passenger can be classified according to gender, adult and child to obtain the heat load generated by each category of passengers, and the car can determine the corresponding number and type of passengers through video recognition; the sunlight intensity can be obtained according to weather information, or by installing corresponding sensors on the outside of the car; the heat transfer coefficient of the window is determined according to the heat transfer coefficient of the window glass.

[0076] According to the cockpit heat load model, the required air conditioning power and the air conditioning energy efficiency ratio, the relationship curve between cockpit temperature and air conditioning power is obtained:

[0077]

[0078] in, is the required air conditioning power, is the energy efficiency ratio of the air conditioner.

[0079] S400. Cooling the battery liquid coolant by the air conditioning system, adding the air conditioning power of the air conditioning system for cooling the battery liquid coolant to a curve showing a relationship between the cockpit temperature and the air conditioning power, and adjusting the battery heat dissipation demand curve based on the adjusted curve showing a relationship between the cockpit temperature and the air conditioning power.

[0080] The battery liquid coolant is cooled by air conditioning, and the cooled liquid coolant is then sent to the battery heat dissipation channel to cool the battery. As we have already known, the cockpit temperature is related to the air conditioning power. The relationship curve of the heat dissipation power under different ambient temperatures and vehicle speeds , the heat dissipation power After dividing by the heat exchange efficiency of the liquid coolant, we can get the power of the air conditioner used for cooling the liquid coolant. The power of the air conditioner used for cooling the liquid coolant and the power of the air conditioner The total air conditioning power is added together to obtain the adjusted relationship curve between cockpit temperature and air conditioning power. The total air conditioning power is added to the load power, and then the battery cooling demand is recalculated through the calculation process of the battery cooling demand curve to obtain the adjusted battery cooling demand curve.

[0081] S500: Based on the battery pack structure and the adjusted battery heat dissipation demand curve, a relationship curve among the outflow temperature, outflow velocity, time, and battery temperature of the liquid coolant is obtained.

[0082] The liquid coolant circulates and exchanges heat according to the structure of the battery pack. The heat dissipation power under certain conditions can be obtained through the adjusted battery heat dissipation demand curve. , according to the heat dissipation power Through the test, we can know the relationship between the liquid coolant's outflow temperature, outflow velocity, battery temperature and time, and construct a relationship curve after fitting.

[0083] The liquid coolant is a nanofluid of γ-Al2O3 / deionized water with a mass concentration of 0.1%-2%. The use of nanofluid can more efficiently exchange heat for the battery.

[0084] S600, collects actual driving data of electric vehicles, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the relationship curve between the outflow temperature and outflow velocity of the liquid coolant, time, and battery temperature, the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow velocity over time are obtained while minimizing the energy consumption of the air conditioner to cool the battery liquid coolant and ensuring that the battery temperature is within a specific range (20-40°C).

[0085] This embodiment provides a specific implementation process of the above steps:

[0086] Build a Markov decision model:

[0087] The battery temperature, cabin temperature, ambient temperature, vehicle speed, and acceleration are defined as the state set S of the MDP;

[0088] Define a control action set A, including power regulation of the air conditioner to cool the battery liquid coolant, liquid coolant outflow temperature control, and inlet flow rate adjustment;

[0089] Designing the reward function , to quantify the Take Action The rear air conditioner minimizes the energy consumption of cooling the battery liquid coolant and ensures that the battery temperature is within a specific range;

[0090] Using actual driving data, the optimal strategy is learned through reinforcement learning algorithms , iteratively updated by the following formula:

[0091]

[0092] in, is the state-action value function, is the learning rate, is the discount factor, Take action The next state after.

[0093] S700: Adjust relevant parameters of heat dissipation of the electric vehicle battery according to the obtained power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time.

[0094] See also Figure 2 , which is an electric vehicle battery cooling system, including a battery simulation model module 100, a cooling demand curve module 200, a cockpit temperature and air conditioning power relationship curve module 300, an adjustment module 400, a liquid coolant related parameter relationship curve module 500, a control strategy optimization module 600 and a battery cooling control module 700.

[0095] The battery simulation model module 100 is used to construct a battery simulation model according to the battery pack structure and battery parameters of the electric vehicle.

[0096] The heat dissipation demand curve module 200 is used to calculate the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds based on the constructed battery simulation model and according to the ambient temperature and electric vehicle related parameters.

[0097] The load power of the power battery is calculated by the electric vehicle driving efficiency, electric vehicle mass, air resistance coefficient, windward area, rolling damping coefficient and vehicle speed:

[0098]

[0099] in, is the driving efficiency of electric vehicles, m is the mass of electric vehicles, is the air resistance coefficient, A is the frontal area, f is the rolling damping coefficient, and u is the vehicle speed.

[0100] The battery operating current is calculated by calculating the load power of the power battery, battery discharge efficiency, motor drive efficiency and battery voltage:

[0101]

[0102] in, is the battery discharge efficiency, is the motor driving efficiency, and U is the battery voltage.

[0103] The battery heat generation power is calculated by the obtained battery operating current, battery equivalent internal resistance and battery temperature:

[0104]

[0105] Where R is the equivalent internal resistance of the battery, T is the battery temperature, is the entropy thermal coefficient.

[0106] The battery heat generation Q is calculated by the battery heat generation power, and the ambient heat dissipation is calculated by the battery specific heat capacity, the total mass of the battery, and the difference between the battery temperature and the ambient temperature:

[0107]

[0108] Where c is the specific heat capacity of the battery, M is the total mass of the battery, is the difference between the battery temperature and the ambient temperature.

[0109] According to the battery heat Q and environmental heat Q m Get the heat dissipation power:

[0110]

[0111] Wherein, t is the heat dissipation time.

[0112] Different ambient temperatures and vehicle speeds can be used to obtain different heat dissipation powers and the battery heat dissipation demand curve. By simulating the battery operating state under different ambient temperatures and vehicle speeds, a series of heat dissipation power values ​​can be calculated to form a heat dissipation demand curve. This curve can be used to guide the design of the electric vehicle's heat dissipation system to ensure that the battery temperature is within the appropriate range.

[0113] The cockpit temperature and air conditioning power relationship curve module 300 is used to construct a cockpit heat load model, and obtain a cockpit temperature and air conditioning power relationship curve according to the cockpit heat load model.

[0114] The cockpit heat load model is constructed by the energy loss caused by the cockpit insulation performance, the heat load generated by the passengers in the cockpit, and the heat transfer heat of the windows:

[0115]

[0116] in, Energy loss due to cockpit insulation performance, is the number of passengers in the cockpit, is the sunlight intensity, is the temperature inside the cockpit, is the ambient temperature, The heat load generated for a single passenger, is the cockpit window area, is the heat transfer coefficient of the window; the heat load generated by a single passenger can be classified according to gender, adult and child to obtain the heat load generated by each category of passengers, and the car can determine the corresponding number and type of passengers through video recognition; the sunlight intensity can be obtained according to weather information, or by installing corresponding sensors on the outside of the car; the heat transfer coefficient of the window is determined according to the heat transfer coefficient of the window glass.

[0117] The adjustment module 400 is used to cool the battery liquid coolant according to the air-conditioning system, add the air-conditioning power of the air-conditioning system to the relationship curve between the cockpit temperature and the air-conditioning power, and adjust the battery heat dissipation demand curve based on the adjusted relationship curve between the cockpit temperature and the air-conditioning power.

[0118] The battery liquid coolant is cooled by air conditioning, and the cooled liquid coolant is then sent to the battery heat dissipation channel to cool the battery. As we have already known, the cockpit temperature is related to the air conditioning power. The relationship curve of the heat dissipation power under different ambient temperatures and vehicle speeds , the heat dissipation power After dividing by the heat exchange efficiency of the liquid coolant, we can get the power of the air conditioner used for cooling the liquid coolant. The power of the air conditioner used for cooling the liquid coolant and the power of the air conditioner The total air conditioning power is added together to obtain the adjusted relationship curve between cockpit temperature and air conditioning power. The total air conditioning power is added to the load power, and then the battery cooling demand is recalculated through the calculation process of the battery cooling demand curve to obtain the adjusted battery cooling demand curve.

[0119] The liquid coolant related parameter relationship curve module 500 is used to obtain a relationship curve of the liquid coolant outflow temperature, outflow flow rate, time, and battery temperature based on the battery pack structure and the adjusted battery heat dissipation demand curve.

[0120] The liquid coolant circulates and exchanges heat according to the structure of the battery pack. The heat dissipation power under certain conditions can be obtained through the adjusted battery heat dissipation demand curve. , according to the heat dissipation power Through the test, we can know the relationship between the liquid coolant's outflow temperature, outflow velocity, battery temperature and time, and construct a relationship curve after fitting.

[0121] The liquid coolant is a nanofluid of γ-Al2O3 / deionized water with a mass concentration of 0.1%-2%. The use of nanofluid can more efficiently exchange heat for the battery.

[0122] The control strategy optimization module 600 is used to collect actual driving data of the electric vehicle, including acceleration, speed, ambient temperature, battery temperature, and temperature in the cockpit. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the liquid coolant outflow temperature, outflow flow rate, time, and battery temperature relationship curve, the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time are obtained while minimizing the energy consumption of the air conditioner to cool the battery liquid coolant and ensuring that the battery temperature is within a specific range.

[0123] The battery heat dissipation control module 700 is used to adjust the relevant parameters of the electric vehicle battery heat dissipation according to the obtained power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described with reference to the preferred embodiments of the present invention, it should be understood by those skilled in the art that various changes may be made in form and details without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A method for dissipating heat from an electric vehicle battery, characterized in that: include: Construct a battery simulation model based on the battery pack structure and battery parameters of electric vehicles; Based on the constructed battery simulation model, the battery heat dissipation demand curve is calculated under different ambient temperatures and vehicle speeds according to the ambient temperature and electric vehicle related parameters; Construct a cockpit heat load model, and obtain the relationship curve between cockpit temperature and air conditioning power based on the cockpit heat load model; According to the air conditioning system cooling the battery liquid coolant, the air conditioning power of the air conditioning system cooling the battery liquid coolant is added to the relationship curve between the cockpit temperature and the air conditioning power, and the battery heat dissipation demand curve is adjusted based on the adjusted relationship curve between the cockpit temperature and the air conditioning power; Based on the battery pack structure and the adjusted battery heat dissipation demand curve, a relationship curve among the outflow temperature, outflow velocity, time and battery temperature of the liquid coolant is obtained; Collect actual driving data of electric vehicles, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the relationship curve between the outflow temperature of the liquid coolant, the outflow flow rate, time, and battery temperature, minimize the energy consumption of the air conditioner to cool the battery liquid coolant and ensure that the battery temperature is within a specific range, derive the control strategy of the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the inlet flow rate over time; Adjust the relevant parameters of electric vehicle battery heat dissipation based on the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time; The battery simulation model constructed based on the battery simulation model calculates the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds according to the ambient temperature and electric vehicle related parameters, including: The load power of the power battery is calculated by the electric vehicle driving efficiency, electric vehicle mass, air resistance coefficient, windward area, rolling damping coefficient and vehicle speed; Calculate the battery operating current by calculating the load power of the power battery, the battery discharge efficiency, the motor drive efficiency and the battery voltage; The battery heat generation power is calculated by the obtained battery operating current, battery equivalent internal resistance and battery temperature; The battery heat generation is calculated by the battery heat generation power, and the ambient heat dissipation is calculated by the battery specific heat capacity, the total mass of the battery, and the difference between the battery temperature and the ambient temperature; The heat dissipation power is obtained according to the heat generated by the battery and the heat dissipation of the environment; Different ambient temperatures and vehicle speeds are used to obtain different heat dissipation powers and the battery heat dissipation demand curve.

2. The electric vehicle battery heat dissipation method according to claim 1, characterized in that: The relationship curve between cockpit temperature and air conditioning power obtained according to the cockpit heat load model includes: The cockpit heat load model is constructed by the energy loss caused by the thermal insulation performance of the cockpit, the heat load generated by the passengers in the cockpit and the heat transferred by the windows; According to the cockpit heat load model, the required air conditioning power and the energy efficiency ratio of the air conditioning, the relationship curve between the cockpit temperature and the air conditioning power is obtained.

3. The electric vehicle battery heat dissipation method according to claim 1, characterized in that: The cooling of the battery liquid coolant by the air conditioning system, adding the air conditioning power of the air conditioning system for cooling the battery liquid coolant to the relationship curve between the cockpit temperature and the air conditioning power, and adjusting the battery heat dissipation demand curve of the air conditioning system power includes: The required air conditioning power and the heat dissipation power are summed up to obtain the total air conditioning power, and a curve of the relationship between the adjusted cockpit temperature and the air conditioning power is formed; The total air-conditioning power of the adjusted cockpit temperature-air-conditioning power relationship curve is added to the load power, and then the battery cooling demand is recalculated to obtain the adjusted battery cooling demand curve.

4. The electric vehicle battery heat dissipation method according to claim 1, characterized in that: The actual driving data of the electric vehicle is collected, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the outflow temperature of the liquid coolant, the outflow flow rate, time, and the relationship curve of the battery temperature, the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time are obtained, while minimizing the energy consumption of the air conditioner to cool the battery liquid coolant. The control strategy includes: Build a Markov decision model: The battery temperature, cabin temperature, ambient temperature, vehicle speed, and acceleration are defined as the state set of the MDP; Define a set of control actions, including power regulation of the air conditioner to cool the battery liquid coolant, liquid coolant outflow temperature control, and inlet flow rate adjustment; Design a reward function to quantify the energy consumption of the air conditioner to cool the battery liquid coolant and ensure that the battery temperature is within a specific range after taking action in a specific state; Using actual driving data, the optimal strategy is learned through a reinforcement learning algorithm, and iterative updates are performed to obtain the control strategy of the air conditioner's power to cool the battery liquid coolant, the liquid coolant's outflow temperature, and the inlet flow rate over time.

5. The electric vehicle battery heat dissipation method according to claim 4, characterized in that: The liquid coolant is a nanofluid of γ-Al2O3 / deionized water with a mass concentration of 0.1%-2%.

6. The electric vehicle battery heat dissipation method according to claim 4, characterized in that: The ensuring that the battery temperature is within a specific range is that the battery temperature is 20-45°C.

7. An electric vehicle battery cooling system, characterized in that: It includes a battery simulation model module, a heat dissipation demand curve module, a cockpit temperature and air conditioning power relationship curve module, an adjustment module, a liquid coolant related parameter relationship curve module, a control strategy optimization module and a battery heat dissipation control module; The battery simulation model module is used to construct a battery simulation model according to the battery pack structure and battery parameters of the electric vehicle; The heat dissipation demand curve module is used to calculate the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds based on the constructed battery simulation model and according to the ambient temperature and electric vehicle related parameters; The cockpit temperature and air conditioning power relationship curve module is used to construct a cockpit heat load model, and obtain a cockpit temperature and air conditioning power relationship curve according to the cockpit heat load model; The adjustment module is used to cool the battery liquid coolant according to the air conditioning system, add the air conditioning power of the air conditioning system to cool the battery liquid coolant to the relationship curve between the cockpit temperature and the air conditioning power, and adjust the battery heat dissipation demand curve based on the adjusted relationship curve between the cockpit temperature and the air conditioning power; The liquid coolant related parameter relationship curve module is used to obtain a relationship curve of the liquid coolant outflow temperature, outflow flow rate, time, and battery temperature based on the battery pack structure and the adjusted battery heat dissipation demand curve; The control strategy optimization module is used to collect actual driving data of the electric vehicle, including acceleration, speed, ambient temperature, battery temperature, and cabin temperature. Based on the Markov decision model and the adjusted battery heat dissipation demand curve, the outflow temperature of the liquid coolant, the outflow flow rate, time, and the relationship curve of the battery temperature, the power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time are obtained while minimizing the energy consumption of the air conditioner to cool the battery liquid coolant and ensuring that the battery temperature is within a specific range; The battery heat dissipation control module is used to adjust the relevant parameters of the electric vehicle battery heat dissipation according to the obtained power of the air conditioner to cool the battery liquid coolant, the outflow temperature of the liquid coolant, and the control strategy of the inlet flow rate over time; The battery simulation model constructed based on the battery simulation model calculates the battery heat dissipation demand curve under different ambient temperatures and vehicle speeds according to the ambient temperature and electric vehicle related parameters, including: The load power of the power battery is calculated by the electric vehicle driving efficiency, electric vehicle mass, air resistance coefficient, windward area, rolling damping coefficient and vehicle speed; Calculate the battery operating current by calculating the load power of the power battery, the battery discharge efficiency, the motor drive efficiency and the battery voltage; The battery heat generation power is calculated by the obtained battery operating current, battery equivalent internal resistance and battery temperature; The battery heat generation is calculated by the battery heat generation power, and the ambient heat dissipation is calculated by the battery specific heat capacity, the total mass of the battery, and the difference between the battery temperature and the ambient temperature; The heat dissipation power is obtained according to the heat generated by the battery and the heat dissipation of the environment; Different ambient temperatures and vehicle speeds are used to obtain different heat dissipation powers and the battery heat dissipation demand curve.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the electric vehicle battery heat dissipation method as claimed in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the electric vehicle battery heat dissipation method as claimed in any one of claims 1 to 6 are implemented.

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