Battery thermal management system modeling method, device, storage medium and computer program

Abstract

The invention relates to the technical field of fuel cells, in particular to a battery thermal management system modeling method and device, a storage medium and a computer program.The method comprises the steps that the performance of a target entity electric pile is fitted to obtain a heat production power calculation model of a simulation electric pile, and the performance of a target entity heat exchanger is fitted to obtain a heat production power calculation model of the simulation electric pile; a heat dissipating capacity calculation model of the simulated radiator is obtained, a mass flow calculation model of cooling liquid output by a simulated water pump, a heat absorption capacity calculation model of the cooling liquid flowing through the galvanic pile and a mass flow calculation model of the cooling liquid flowing through the simulated radiator are constructed, all the calculation models are comprehensively constructed, and a battery thermal management system model is obtained. According to the modeling method disclosed by the invention, model building can be completed on a single modeling platform, for example, a thermal management model which is more in line with physical performance is built by using Simulink software, and the problem that the real-time performance of joint simulation is difficult to meet due to the fact that the simulation speed is easily reduced when multiple pieces of software are operated at the same time is solved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of fuel cells, and in particular to a battery thermal management system modeling method, device, storage medium and computer program. Background Art

[0002] With the rapid development of technology, the application of proton exchange membrane fuel cells (PEMFC) is becoming more and more widespread. Usually, the heat generated by PEMFC is equivalent to the electrical energy it outputs. The balance between heat generation and heat removal determines the operating temperature of PEMFC, and its temperature seriously affects the performance and life of the fuel cell. In order to ensure the long-term stable and safe operation of the stack, its temperature needs to be controlled within a suitable range.

[0003] AMEsim software has a professional fuel cell system model library, a high degree of integration, and provides a wealth of analysis tools and practical application cases. It can realize the construction of a one-dimensional simulation model of the fuel cell thermal management system and perform system performance evaluation and optimization. However, AMEsim software lacks modeling capabilities in control model construction and switching between different states, and is somewhat weak when conducting dynamic characteristic research under complex working conditions. In order to overcome the limitations of a single simulation software, a joint simulation method is usually used. Specifically, AMEsim is used to build a one-dimensional simulation model of the fuel cell system to take advantage of its professional model library and integration advantages; at the same time, Simulink is used to build a control model to implement complex control strategies and logic. Through the interface between the two software (such as Simulink's S-Function or AMEsim's interface module), real-time data exchange and synchronous simulation can be achieved.

[0004] However, during the joint simulation process, running two software at the same time and exchanging data can easily lead to a decrease in simulation speed, especially in application scenarios that deal with complex models or require real-time simulation. Because of delays in data exchange and synchronous control, joint simulation is difficult to meet real-time requirements. Summary of the invention

[0005] The present disclosure provides a battery thermal management system modeling method, device, storage medium and computer program to solve the problem that in a joint simulation process, running two softwares simultaneously and exchanging data easily leads to a decrease in simulation speed and difficulty in meeting real-time requirements.

[0006] In a first aspect, the present disclosure provides a battery thermal management system modeling method, comprising:

[0007] Fitting the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage;

[0008] Constructing a heat generation power calculation model for simulating the battery stack according to the total output voltage, the preset current density, the preset activation area, and the preset number of battery stack cells;

[0009] Obtaining a heat transfer coefficient of a target physical radiator, and constructing a heat dissipation calculation model for simulating the radiator according to the heat transfer coefficient, a preset number of fans, a preset heat exchange area, and a preset ambient temperature;

[0010] According to the relationship between the rotation speed of the water pump and the mass flow rate of the coolant, a calculation model for the mass flow rate of the coolant output by the water pump is constructed;

[0011] According to the preset specific heat capacity of the coolant and the coolant mass flow rate output by the coolant mass flow rate calculation model output by the simulated water pump, a heat absorption calculation model after the coolant flows through the fuel cell stack is constructed;

[0012] Constructing a temperature calculation model for the simulated fuel cell stack according to the heat generation power calculation model of the simulated fuel cell stack, the heat absorption calculation model after the coolant flows through the fuel cell stack, the preset specific heat capacity of the fuel cell stack, and the preset fuel cell stack mass;

[0013] According to the flow diversion principle of the thermostat, a coolant mass flow calculation model flowing through the simulated radiator is constructed;

[0014] Constructing a structural model of a battery thermal management system, wherein the structural model includes a simulated battery stack structural model, a simulated thermostat structural model, a simulated coolant structural model, a simulated water pump structural model, and a simulated radiator structural model, wherein the output end of the simulated battery stack structural model is connected to the input end of the simulated thermostat structural model, the first output end of the simulated thermostat structural model is connected to the input end of the simulated water pump structural model, the second output end of the simulated thermostat structural model is connected to the input end of the simulated radiator structural model, the output end of the simulated radiator structural model is connected to the input end of the simulated water pump structural model, the output end of the simulated water pump structural model is connected to the input end of the simulated battery stack structural model, and the simulated coolant structural model is used to simulate the coolant flowing through the simulated battery stack structural model, the simulated thermostat structural model, the simulated water pump structural model, and the simulated radiator structural model;

[0015] A battery thermal management system model is constructed based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator and the structural model of the battery thermal management system.

[0016] In one embodiment, the heat generation power calculation model of the simulated fuel cell stack is as follows:

[0017] P heat =(U-1.254·N cell )·i·A / 1000,

[0018] Among them, P heat To simulate the heat generation power of the battery stack, U is the total output voltage, N cell is the number of single cells in the battery stack, and A is the activation area.

[0019] In one embodiment, the heat dissipation calculation model of the simulated radiator is as follows:

[0020] Q rad =N fan ·h rad ·A(T rad -T env ),

[0021] Among them, Q rad is the heat dissipation of the simulated radiator, N fan is the number of fans, h rad is the heat transfer coefficient, A is the heat transfer area, T rad is the temperature of the simulated heat sink during operation, T env is the ambient temperature.

[0022] In one embodiment, the calculation model of the heat absorption calculation model after the coolant flows through the battery stack is expressed as follows:

[0023] Q cw =C cw ·M cw (T st_out -T st_in ),

[0024] Among them, Q cw is the heat absorbed by the coolant after flowing through the battery stack, C cw is the specific heat capacity of the coolant, M cw is the coolant mass flow rate, T st_in is the coolant inlet temperature of the stack, T st_out is the coolant outlet temperature of the fuel cell stack.

[0025] In one embodiment, the calculation model of the coolant mass flow rate flowing through the radiator is expressed as follows:

[0026]

[0027] Among them, M rad is the coolant mass flow rate flowing through the radiator, V opening is the opening of the thermostat, the value range of the opening is [0, 85], M cw is the coolant mass flow rate.

[0028] Coolant mass flow M that does not flow through the radiator and directly enters the circulating water pump module minor The calculation formula is as follows:

[0029] M minor =M cw -M rad .

[0030] In one embodiment, the method further comprises:

[0031] Constructing a temperature calculation model for the simulated fuel cell stack according to the heat generation power calculation model of the simulated fuel cell stack, the heat absorption calculation model after the coolant flows through the fuel cell stack, the preset specific heat capacity of the fuel cell stack, and the preset fuel cell stack mass;

[0032] The steps of constructing the battery thermal management system model include:

[0033] A battery thermal management system model is constructed based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator and the structural model of the battery thermal management system.

[0034] In one embodiment, the step of fitting the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage includes:

[0035] Within a preset current density range, adjusting the current density value of the target physical battery stack, and recording the total output voltage at the corresponding current density value;

[0036] The current density values ​​and the corresponding total output voltages are fitted to obtain a calculation formula for the total output voltage.

[0037] In a second aspect, the present disclosure provides a battery thermal management system modeling device, comprising:

[0038] A fitting module is used to fit the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage;

[0039] A first construction module is used to construct a heat generation power calculation model of the simulated battery stack according to the total output voltage, the preset current density, the preset activation area and the preset number of battery stack cells;

[0040] The second construction module is used to obtain the heat transfer coefficient of the target physical radiator, and construct a heat dissipation calculation model of the simulated radiator according to the heat transfer coefficient, a preset number of fans, a preset heat exchange area and a preset ambient temperature;

[0041] The third construction module is used to construct a coolant mass flow calculation model simulating the output of the water pump according to the relationship between the rotation speed of the water pump and the coolant mass flow;

[0042] A fourth construction module is used to construct a heat absorption calculation model after the coolant flows through the fuel cell stack according to a preset specific heat capacity of the coolant and the coolant mass flow rate output by the coolant mass flow rate calculation model output by the simulated water pump;

[0043] A fifth construction module is used to construct a temperature calculation model of the simulated fuel cell according to the heat generation power calculation model of the simulated fuel cell, the heat absorption calculation model after the coolant flows through the fuel cell, the preset specific heat capacity of the fuel cell, and the preset fuel cell mass;

[0044] a sixth construction module, configured to construct a coolant mass flow calculation model flowing through the simulated radiator according to a flow splitting principle of a thermostat;

[0045] A comprehensive construction module, used to construct a structural model of a battery thermal management system, wherein the structural model includes a simulated battery stack structural model, a simulated thermostat structural model, a simulated coolant structural model, a simulated water pump structural model and a simulated radiator structural model, the output end of the simulated battery stack structural model is connected to the input end of the simulated thermostat structural model, the first output end of the simulated thermostat structural model is connected to the input end of the simulated water pump structural model, the second output end of the simulated thermostat structural model is connected to the input end of the simulated radiator structural model, the output end of the simulated radiator structural model is connected to the input end of the simulated water pump structural model, the output end of the simulated water pump structural model is connected to the input end of the simulated battery stack structural model, and the simulated coolant structural model is used to simulate the coolant flowing through the simulated battery stack structural model, the simulated thermostat structural model, the simulated water pump structural model and the simulated radiator structural model;

[0046] A battery thermal management system model is constructed based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator and the structural model of the battery thermal management system.

[0047] In a third aspect, the present disclosure provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the above aspects.

[0048] In a fourth aspect, the present disclosure provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method described in the above aspects when executed by a processor.

[0049] In a fifth aspect, the present disclosure provides a computer program product, including a computer program / instructions, which implements the steps of the method described in the above aspects when the computer program is executed by a processor.

[0050] The present disclosure provides a battery thermal management system modeling method, device, storage medium and computer program, which can fit the performance of the target entity battery stack and heat exchanger so that the fitting calculation formula can more accurately reflect the actual working state of the battery stack and heat exchanger, thereby improving the accuracy of the simulation model. At the same time, the present disclosure takes into account multiple key components of the battery thermal management system, including the battery stack, radiator, water pump, coolant and thermostat, and builds corresponding simulation models for each component. This comprehensive modeling method can more comprehensively reflect the complexity and dynamics of the battery thermal management system and improve the reliability of the simulation. By simulating the operation process of the battery thermal management system, key parameters such as heat generation power, heat dissipation, coolant mass flow rate and heat absorption of the system under different working conditions can be predicted, which helps to discover and solve potential thermal management problems in advance, optimize system design and operation strategies, and improve the safety and efficiency of the system. The modeling method disclosed in the present disclosure can complete the construction of the model on a single modeling platform, such as using Simulink software to build a thermal management model that is more in line with the actual performance, solving the problem that running two softwares at the same time and exchanging data in the prior art easily leads to a decrease in simulation speed, making it difficult for joint simulation to meet real-time requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:

[0052] Figure 1 A schematic diagram of a flow chart of a battery thermal management system modeling method provided in an embodiment of the present disclosure;

[0053] Figure 2 A battery thermal management system model block diagram provided in an embodiment of the present disclosure;

[0054] Figure 3 A battery thermal management system modeling device is provided in an embodiment of the present disclosure.

[0055] In the drawings, the same reference numerals are used for the same components, and the drawings are not drawn to scale. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, and to fully understand and implement how the present disclosure applies technical means to solve technical problems and achieve the corresponding technical effects, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only embodiments of a part of the present disclosure, not all of the embodiments. The embodiments of the present disclosure and the various features in the embodiments can be combined with each other without conflict, and the technical solutions formed are all within the scope of protection of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present disclosure.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0058] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0059] Embodiment 1

[0060] Figure 1 A flow chart of a battery thermal management system modeling method provided by an embodiment of the present disclosure. Figure 1 As shown, a battery thermal management system modeling method includes:

[0061] Step 110, fitting the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage;

[0062] In this embodiment, after setting up the equipment and experimental environment required for the fitting experiment, the current density value is gradually changed within the selected current density range, and the total output voltage of the battery stack under the corresponding conditions is recorded. Each current density point can be measured multiple times and the average value is taken to improve the accuracy and reliability of the data. Afterwards, the data obtained from the experimental measurement are sorted to form a corresponding relationship table or graph between the current density and the total output voltage. According to the characteristics and distribution law of the experimental data, a suitable mathematical model is selected for fitting. The fitting model can be selected from polynomial fitting, exponential fitting, logarithmic fitting, etc., and is selected according to actual needs, and is not specifically limited here.

[0063] For example, by analyzing the characteristics of the target physical battery stack, the following relationship between the total output voltage and current density of the battery stack is obtained:

[0064]

[0065] Wherein, i is the current density, U is the total output voltage, a, b, c, and d are all constants. For different physical battery stacks, the values ​​of a, b, c, and d obtained after characteristic fitting are different.

[0066] Step 120, constructing a heat generation power calculation model for simulating the battery stack according to the total output voltage, the preset current density, the preset activation area, and the preset number of battery stack cells;

[0067] In this embodiment, according to the total output voltage, the output power of the battery stack can be expressed as:

[0068] P elec =U·i·A / 1000,

[0069] Among them, P elec is the output power of the battery stack, and A is the activation area.

[0070] According to the heat generation characteristics of the battery stack, the heat generation power of the battery stack can be obtained as:

[0071] P heat =(U-1.254·N cell )·i·A / 1000,

[0072] Among them, P heat To simulate the heat generation power of the battery stack, N cell is the number of single cells in the battery stack.

[0073] It is understandable that the battery stack will generate a lot of heat during operation, and the generation of this heat is related to many factors such as the output power, working efficiency and internal chemical reaction of the battery stack. By fitting the heat generation power calculation model, the heat generation characteristics of the battery stack under different working conditions can be more accurately described, thereby improving the accuracy of the battery stack model.

[0074] Step 130, obtaining a heat transfer coefficient of the target physical radiator, and constructing a heat dissipation calculation model for simulating the radiator according to the heat transfer coefficient, a preset number of fans, a preset heat transfer area, and a preset ambient temperature;

[0075] In a fuel cell thermal management system, as the radiator fan rotates, air and radiator fins undergo convective heat exchange. The heat transfer coefficient is an important parameter of radiator performance, reflecting the efficiency of heat exchange between the radiator surface and the surrounding fluid (such as air). The heat transfer coefficient is affected by many factors such as the radiator material, shape, surface condition, and fluid properties (such as wind speed and temperature). In this embodiment, the heat transfer coefficient can be obtained by experimental measurement or by referring to relevant technical documents.

[0076] Number of fans: Fans are used to increase air flow, thereby improving the cooling effect. The more fans there are, the greater the air volume and the more efficient the cooling. Heat exchange area: The larger the effective cooling area of ​​the radiator, the more heat can be exchanged. Ambient temperature: Ambient temperature is an important external factor in the cooling effect of the radiator. The higher the ambient temperature, the more heat the radiator needs to discharge, and the difficulty of cooling increases accordingly.

[0077] In this embodiment, by considering parameters such as heat transfer coefficient, number of fans, heat exchange area, ambient temperature, etc. to construct a radiator heat dissipation calculation model, it can help to more accurately characterize the heat dissipation performance of the radiator.

[0078] In one embodiment, the heat dissipation calculation model of the simulated radiator is as follows:

[0079] Q rad =N fan ·h rad ·A(T rad -T env ),

[0080] Among them, Q rad To simulate the heat dissipation of the radiator, N fan is the number of fans, h rad is the heat transfer coefficient, A is the heat transfer area, T rad To simulate the temperature of the radiator during operation, T env is the ambient temperature.

[0081] Step 140, constructing a coolant mass flow calculation model simulating the output of the water pump according to the relationship between the rotation speed of the water pump and the coolant mass flow;

[0082] The speed of the water pump determines the speed of the impeller rotation, which in turn affects the speed at which the coolant is sucked in and discharged. Generally, the higher the speed of the water pump, the greater the amount of coolant (or coolant mass flow rate) passing through the water pump per unit time.

[0083] Based on the relationship between the speed and mass flow of the water pump, a coolant mass flow calculation model simulating the output of the water pump is constructed, so that different coolant mass flow rates can be output correspondingly by inputting different speed values.

[0084] Step 150, constructing a heat absorption calculation model after the coolant flows through the fuel cell stack according to a preset specific heat capacity of the coolant and a coolant mass flow rate output by the coolant mass flow rate calculation model output by the simulated water pump;

[0085] For fuel cell systems, hydrogen and oxygen undergo a redox reaction inside the stack through the catalysis of a catalyst, thereby generating electrical energy. About half of the energy is generated in the form of heat, and the efficient operating temperature range of the stack is generally 60°C to 80°C. In order to avoid overheating that affects the stability and durability of the stack, a circulating water pump must be used to remove the heat generated by the stack through the coolant. At the same time, the coolant and air are subjected to convection heat exchange through the radiator to remove the heat in the coolant. The coolant, which has been cooled by the radiator, re-enters the stack for circulation.

[0086] According to the principles of thermodynamics, the heat absorbed by the coolant can be calculated by the following formula:

[0087] Q cw =C cw ·M cw (T st_out -T st_in ),

[0088] Among them, Q cw is the heat absorbed by the coolant after flowing through the battery stack, C cw is the specific heat capacity of the coolant, M cw is the coolant mass flow rate, T st_in is the coolant inlet temperature of the stack, T st_out is the coolant outlet temperature of the fuel cell stack.

[0089] Step 160, constructing a temperature calculation model for the simulated fuel cell stack according to the heat generation power calculation model of the simulated fuel cell stack, the heat absorption calculation model after the coolant flows through the fuel cell stack, the preset specific heat capacity of the fuel cell stack, and the preset fuel cell stack mass;

[0090] In this embodiment, on the basis of the battery thermal management system model described above, a simulation stack temperature calculation model is added and integrated into the simulation stack model. The simulation stack temperature calculation model is constructed based on four main parameters: a simulation radiator heat dissipation calculation model, a coolant absorption heat calculation model after flowing through the stack, a preset stack specific heat capacity, and a preset stack mass.

[0091] The temperature change of the battery stack depends on its heat generation, heat dissipation and its own heat capacity. The heat generation is given by the heat generation power calculation model that simulates the battery stack, and the heat dissipation is estimated by the process of coolant flowing in the battery stack and absorbing heat and then dissipating it through the radiator (using the heat dissipation calculation model that simulates the radiator and the heat absorption calculation model after the coolant flows through the battery stack). The specific heat capacity and mass of the battery stack determine the magnitude of its temperature change under a given heat change.

[0092] By constructing a temperature calculation model that simulates the battery stack, the temperature of the battery stack can be calculated in real time, so that the battery thermal management system model can more accurately predict the temperature changes of the battery stack and adjust the thermal management strategy accordingly, such as adjusting the circulation speed of the coolant, changing the heat dissipation capacity of the radiator, etc., to ensure the stable and safe operation of the battery stack.

[0093] In one embodiment, the temperature calculation model of the simulated stack is as follows:

[0094]

[0095] Among them, C st is the specific heat capacity of the battery stack, M st is the mass of the battery stack, P heat To simulate the heat generation power of the battery stack, Q cw It is the amount of heat absorbed by the coolant after flowing through the battery stack.

[0096] Step 170, constructing a coolant mass flow calculation model flowing through the simulated radiator according to the flow splitting principle of the thermostat;

[0097] The thermostat in the fuel cell system plays a vital role in the heating and cooling process of the fuel cell stack. In this embodiment, the thermostat can be a three-way valve, which is structurally manifested as one inlet and two outlets. The rotation of the internal valve core determines the flow area of ​​the two outlets, so that the coolant is diverted after flowing through the thermostat and enters different circulation paths.

[0098] In one embodiment, the calculation model of the coolant mass flow rate flowing through the radiator is expressed as follows:

[0099]

[0100] Among them, M radis the coolant mass flow rate flowing through the radiator, V opening is the opening of the thermostat, the value range of the opening is [0, 85], M cw is the coolant mass flow rate.

[0101] Coolant mass flow M that does not flow through the radiator and directly enters the circulating water pump module minor The calculation formula is as follows:

[0102] M minor =M cw -M rad .

[0103] When the stack is just started, in order to stabilize the energy supply effect, the stack is usually not cooled immediately. At this time, the opening of the thermostat is 0, the coolant does not flow through the radiator, and the temperature of the coolant will continue to rise during this process. As the output power of the stack continues to increase, the coolant temperature continues to rise. In order to avoid overheating, the thermostat needs to be turned on to maintain the coolant temperature within a suitable range through the radiator. Therefore, at this stage when the thermostat opening changes, the temperature of the coolant that does not flow through the radiator is different from the temperature of the coolant that flows through the radiator, and the two are mixed and enter the stack. When the thermostat opening reaches 85, it means that all the coolant flows through the radiator at this time, and the coolant is quickly cooled through the radiator.

[0104] Step 180, constructing a structural model of a battery thermal management system, wherein the structural model includes a simulated battery stack structural model, a simulated thermostat structural model, a simulated coolant structural model, a simulated water pump structural model, and a simulated radiator structural model, the output end of the simulated battery stack structural model is connected to the input end of the simulated thermostat structural model, the first output end of the simulated thermostat structural model is connected to the input end of the simulated water pump structural model, the second output end of the simulated thermostat structural model is connected to the input end of the simulated radiator structural model, the output end of the simulated radiator structural model is connected to the input end of the simulated water pump structural model, the output end of the simulated water pump structural model is connected to the input end of the simulated battery stack structural model, and the simulated coolant structural model is used to simulate the coolant flowing through the simulated battery stack structural model, the simulated thermostat structural model, the simulated water pump structural model, and the simulated radiator structural model;

[0105] A battery thermal management system model is constructed based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator and the structural model of the battery thermal management system.

[0106] In this example, Figure 2 As shown, it is a block diagram of the battery thermal management system model constructed in this embodiment. During the normal loading process of the fuel cell system, the initial temperature of the coolant is not high. In order to quickly heat up the stack, the flow path of the coolant is generally controlled by the thermostat so that the coolant does not flow through the radiator. At this time, the thermostat is in the closed stage, and the flow path of the coolant is circulating water pump → stack → thermostat → circulating water pump, which is called a small cycle. As the power of the stack increases, the coolant temperature gradually increases. After reaching a certain temperature, the thermostat opens. As the opening increases, the small circulation flow gradually decreases, while the flow through the radiator gradually increases. This is the transition stage, and the coolant flows through the small circulation and the radiator at the same time. When the thermostat is fully opened, the flow path of the coolant is circulating water pump → stack → thermostat → radiator → circulating water pump, which is called a large cycle. At this time, the temperature of the coolant will also tend to be stable. The mutual cooperation of the various components of the thermal management system ensures the efficient operation of the stack.

[0107] The battery thermal management system model integrates all the above sub-models to form a complete battery thermal management system simulation environment. In this system, the simulated water pump drives the coolant to circulate between the battery stack, thermostat, radiator and water pump under the regulation of the thermostat to achieve effective heat transfer and dissipation.

[0108] In summary, the present disclosure provides a battery thermal management system modeling method, which fits the performance of the target entity battery stack and heat exchanger so that the fitting calculation formula can more accurately reflect the actual working state of the battery stack and heat exchanger, thereby improving the accuracy of the simulation model. At the same time, the present disclosure takes into account multiple key components of the battery thermal management system, including the battery stack, radiator, water pump, coolant and thermostat, and builds corresponding simulation models for each component. This comprehensive modeling method can more comprehensively reflect the complexity and dynamics of the battery thermal management system and improve the reliability of the simulation. By simulating the operation process of the battery thermal management system, key parameters such as heat generation power, heat dissipation, coolant mass flow rate and heat absorption of the system under different working conditions can be predicted, which helps to discover and solve potential thermal management problems in advance, optimize system design and operation strategies, and improve the safety and efficiency of the system. The modeling method disclosed in the present disclosure can complete the construction of the model on a single modeling platform, such as using Simulink software to build a thermal management model that is more in line with the actual performance, which solves the problem that running two software at the same time and exchanging data in the prior art easily leads to a decrease in simulation speed, making it difficult for joint simulation to meet real-time requirements.

[0109] In one embodiment, the method also includes: constructing a temperature calculation model of a simulated battery stack based on a heat generation power calculation model of the simulated battery stack, a heat absorption calculation model after the coolant flows through the battery stack, a preset specific heat capacity of the battery stack, and a preset battery stack mass; the step of constructing a battery thermal management system model includes: constructing a battery thermal management system model based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator, and the structural model of the battery thermal management system.

[0110] Embodiment 2

[0111] Based on the above embodiments, this embodiment provides an application example.

[0112] In this embodiment, a fuel cell stack model, a circulating water pump model, a coolant model, a radiator model and a thermostat model are built in Simulink software to construct a fuel cell thermal management system model. Specifically, the following are included:

[0113] 2.1. Construction of battery stack model

[0114] By fitting the characteristics of the battery stack, the following relationship between the total output voltage and current density of the battery stack is obtained:

[0115]

[0116] Where i is the current density, U is the total output voltage, and a, b, c, and d are all constants.

[0117] According to the total output voltage, the output power of the battery stack can be expressed as:

[0118] P elec =U·i·A / 1000

[0119] Among them, P elec is the output power of the battery stack, and A is the activation area.

[0120] According to the heat generation characteristics of the battery stack, the heat generation power of the battery stack can be obtained as:

[0121] P heat =(U-1.254·N cell )·i·A / 1000,

[0122] Among them, P heat To simulate the heat generation power of the battery stack, N cell is the number of single cells in the battery stack.

[0123] 2.2 Coolant Model

[0124] Generally speaking, the heat lost between the battery stack and the environment through convection and radiation does not exceed 5% of the total heat. In the thermal balance analysis and modeling process, this part of the heat can be ignored, and only the heat taken away from the battery stack by the coolant is considered. The difference between the total heat generation and the heat absorbed by the coolant is manifested as an increase in the temperature of the battery stack.

[0125] The coolant flows through the stack to absorb heat, which can be expressed as:

[0126] Q cw =C cw ·M cw (T st_out -T st_in ),

[0127] Among them, Q cw is the heat absorbed by the coolant after flowing through the battery stack, C cw is the specific heat capacity of the coolant, M cw is the coolant mass flow rate, T st_in is the coolant inlet temperature of the stack, T st_out is the coolant outlet temperature of the fuel cell stack.

[0128] According to the thermal balance relationship of the battery stack, without considering the temperature uniformity inside the battery stack, the following thermal balance equation can be obtained:

[0129]

[0130] Among them, C st is the specific heat capacity of the battery stack, M st is the mass of the battery stack, T st is the stack temperature.

[0131] Then the temperature calculation model of the battery stack is obtained as follows:

[0132]

[0133] 2.3 Circulating water pump model

[0134] According to the similarity law, for the same type of circulating water pump, the flow rate and speed have the following corresponding relationship:

[0135]

[0136] Among them, n0 and M0 are the water pump speed and the corresponding coolant mass flow rate under a certain working condition, respectively, and correspondingly, n1 and M1 are the water pump speed and coolant flow rate under another working condition.

[0137] 2.4 Radiator Model

[0138] In the fuel cell thermal management system, as the radiator fan rotates, the air and the radiator fins undergo convective heat exchange. The specific equation is as follows:

[0139] Q rad =N fan ·h rad ·A(T rad -T env ),

[0140] Among them, Q rad is the heat dissipation of the radiator, N fan is the number of fans, h rad is the heat transfer coefficient, A is the heat transfer area, T rad is the temperature of the radiator during operation, T env is the ambient temperature.

[0141] In this embodiment, T rad =(T rad_out +T rad_in ) / 2.

[0142] According to the heat balance relationship, the heat absorbed by the air is equal to the heat lost by the coolant through the radiator, so the coolant outlet temperature of the radiator can be deduced as:

[0143]

[0144] Among them, T rad_out is the coolant outlet temperature of the radiator, T rad_in is the coolant inlet temperature of the radiator, M rad is the coolant mass flow rate flowing through the radiator.

[0145] In the system modeling process of this embodiment, the heat loss of the coolant flowing through the system pipeline is ignored. Therefore, the outlet coolant temperature of the stack is equal to the inlet coolant temperature of the radiator, that is:

[0146] T rad_in =T st_out

[0147] 2.5 Thermostat Model

[0148] In this embodiment, a three-way valve is used, and the rotation of the internal valve core determines the flow area of ​​the two outlets. According to the working principle of the thermal management system and the working characteristics of the thermostat, the following relationship is obtained:

[0149]

[0150] Among them, M rad is the coolant mass flow rate flowing through the radiator, V opening is the opening of the thermostat. In this embodiment, Vopening The value can be 0 to 85.

[0151] It is not difficult to see that as the thermostat opening increases, the total flow of the circulating water pump is equal to the sum of the flow of the small circulation and the large circulation. When the thermostat is fully opened, all the coolant flows through the radiator, that is:

[0152] M cw =M rad +M minor ,

[0153] Among them, M minor It is the coolant mass flow that does not flow through the radiator but directly enters the circulating water pump module.

[0154] As the output power of the fuel cell stack increases, the coolant temperature continues to rise. To avoid overheating, the thermostat needs to be opened, so that the coolant temperature can be maintained within a suitable range through the radiator. Therefore, during the stage when the thermostat opening changes, the coolant temperature of the small cycle is different from the coolant temperature flowing through the radiator. The two mix and enter the fuel cell stack. At this time, the coolant temperature is expressed as the fuel cell inlet temperature, that is, T st_in . By analyzing the above process based on the principles of heat transfer, we can obtain the following equation:

[0155] C cw ·M minor (T st_out -T st_in )=C cw ·M rad (T st_in -T rad_out )

[0156] Expanding the above formula and deriving the calculation formula for the coolant inlet temperature of the stack is as follows:

[0157]

[0158] 2.6. Run the model and observe the temperature change of the model

[0159] After building the above models, set the initial operating parameters, such as water pump speed, thermostat opening, ambient temperature, etc., and run the model. As the running time increases, the temperature of the battery stack, the inlet / outlet temperature of the coolant of the battery stack, and the inlet / outlet temperature of the coolant of the radiator will change.

[0160] The fuel cell thermal management system model of this embodiment can realize dynamic monitoring of parameters such as system power, heat, temperature, flow and water pump speed, provide guidance for the architecture design and performance optimization of the thermal management system, and facilitate the analysis of influencing factors of the thermal management system and dynamic characteristics of typical working conditions; in addition, in the later stage, the control model can be directly built in the Simulink environment, combined with the one-dimensional simulation model to further realize the development and application of the system control algorithm, which can more simply and conveniently realize the dynamic characteristics analysis of complex working conditions, and facilitate the sorting out and improvement of the thermal management system control strategy.

[0161] Embodiment 3

[0162] Based on the above embodiments, Figure 3 As shown, this embodiment provides a battery thermal management system modeling device, including:

[0163] A fitting module 310 is used to fit the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage;

[0164] A first construction module 320 is used to construct a heat generation power calculation model of the simulated battery stack according to the total output voltage, the preset current density, the preset activation area and the preset number of battery stack cells;

[0165] The second construction module 330 is used to obtain the heat transfer coefficient of the target entity radiator, and construct a heat dissipation calculation model of the simulated radiator according to the heat transfer coefficient, the preset number of fans, the preset heat transfer area and the preset ambient temperature;

[0166] The third construction module 340 is used to construct a coolant mass flow calculation model simulating the coolant mass flow output by the water pump according to the relationship between the rotation speed of the water pump and the coolant mass flow;

[0167] The fourth construction module 350 is used to construct a heat absorption calculation model after the coolant flows through the fuel cell stack according to a preset specific heat capacity of the coolant and the coolant mass flow rate output by the coolant mass flow rate calculation model output by the simulated water pump;

[0168] The fifth construction module 360 ​​is used to construct a temperature calculation model of the simulated fuel cell according to the heat generation power calculation model of the simulated fuel cell, the heat absorption calculation model after the coolant flows through the fuel cell, the preset fuel cell specific heat capacity and the preset fuel cell mass.

[0169] A sixth construction module 370 is used to construct a coolant mass flow calculation model flowing through the simulated radiator according to the flow diversion principle of the thermostat;

[0170] A comprehensive construction module 380, for constructing a structural model of a battery thermal management system, wherein the structural model includes a simulated battery stack structural model, a simulated thermostat structural model, a simulated coolant structural model, a simulated water pump structural model and a simulated radiator structural model, the output end of the simulated battery stack structural model is connected to the input end of the simulated thermostat structural model, the first output end of the simulated thermostat structural model is connected to the input end of the simulated water pump structural model, the second output end of the simulated thermostat structural model is connected to the input end of the simulated radiator structural model, the output end of the simulated radiator structural model is connected to the input end of the simulated water pump structural model, the output end of the simulated water pump structural model is connected to the input end of the simulated battery stack structural model, and the simulated coolant structural model is used to simulate the coolant flowing through the simulated battery stack structural model, the simulated thermostat structural model, the simulated water pump structural model and the simulated radiator structural model;

[0171] A battery thermal management system model is constructed based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator and the structural model of the battery thermal management system.

[0172] In one embodiment, the fitting module comprises:

[0173] An adjustment unit, used to adjust the current density value of the target physical battery stack within a preset current density range, and record the total output voltage at the corresponding current density value;

[0174] The fitting unit is used to fit each of the current density values ​​and the corresponding total output voltages to obtain a calculation formula for the total output voltage.

[0175] For the specific limitations of the battery thermal management system modeling device, please refer to the limitations of the battery thermal management system modeling method above, which will not be repeated here. Each unit in the above-mentioned battery thermal management system modeling device can be implemented in whole or in part through software, hardware and a combination thereof. The above-mentioned units can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned units.

[0176] Embodiment 4

[0177] On the basis of the above embodiments, this embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the above embodiments.

[0178] In some implementations of this embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the above embodiment are implemented.

[0179] In some implementations of this embodiment, a computer program product is provided, including a computer program / instructions, and when the computer program is executed by a processor, the steps of the method described in the above embodiment are implemented.

[0180] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor or other electronic components to execute the method in the above embodiments.

[0181] Computer-readable storage media can be implemented by any type of volatile or non-volatile storage device or a combination thereof. Computer-readable storage media may include, but are not limited to, for example, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, computer storage media (such as hard disks, floppy disks, solid-state drives, removable disks, Blu-ray disks, etc.).

[0182] The computer-readable storage medium may also store at least one computer executable program / instruction, which may be, for example, a computer-readable instruction. The computer-readable storage medium includes, but is not limited to, for example, a volatile memory and / or a non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The computer-readable storage medium may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device runs the computer-readable instructions stored on the computer-readable storage medium, the various methods described above may be performed.

[0183] In addition, the electronic device may also include (but not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (eg, keyboard, mouse, speaker, etc.), etc.

[0184] The processor may communicate with external devices via an I / O bus via a wired or wireless network.

[0185] In one embodiment, the at least one computer executable instruction may also be compiled into or constitute a software product / computer program product, wherein one or more computer executable instructions are executed by a processor to perform the various functions and / or method steps in the embodiments described in the present technology.

[0186] In the embodiments provided in the present disclosure, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0187] It should be noted that in the present disclosure, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element limited by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0188] Although the embodiments disclosed in the present disclosure are as above, the above contents are only embodiments adopted for facilitating the understanding of the present disclosure and are not intended to limit the present disclosure. Any technician in the technical field to which the present disclosure belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present disclosure, but the scope of patent protection of the present disclosure shall still be subject to the scope defined in the attached claims.

Claims

1. A battery thermal management system modeling method, It is characterized in that include: Fitting the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage; Constructing a heat generation power calculation model for simulating the battery stack according to the total output voltage, the preset current density, the preset activation area, and the preset number of battery stack cells; Obtaining a heat transfer coefficient of a target physical radiator, and constructing a heat dissipation calculation model for simulating the radiator according to the heat transfer coefficient, a preset number of fans, a preset heat exchange area, and a preset ambient temperature; According to the relationship between the rotation speed of the water pump and the mass flow rate of the coolant, a calculation model for the mass flow rate of the coolant output by the water pump is constructed; According to the preset specific heat capacity of the coolant and the coolant mass flow rate output by the coolant mass flow rate calculation model output by the simulated water pump, a heat absorption calculation model after the coolant flows through the fuel cell stack is constructed; Constructing a temperature calculation model for the simulated fuel cell stack according to the heat generation power calculation model of the simulated fuel cell stack, the heat absorption calculation model after the coolant flows through the fuel cell stack, the preset specific heat capacity of the fuel cell stack, and the preset fuel cell stack mass; According to the flow diversion principle of the thermostat, a coolant mass flow calculation model flowing through the simulated radiator is constructed; Constructing a structural model of a battery thermal management system, wherein the structural model includes a simulated battery stack structural model, a simulated thermostat structural model, a simulated coolant structural model, a simulated water pump structural model, and a simulated radiator structural model, wherein the output end of the simulated battery stack structural model is connected to the input end of the simulated thermostat structural model, the first output end of the simulated thermostat structural model is connected to the input end of the simulated water pump structural model, the second output end of the simulated thermostat structural model is connected to the input end of the simulated radiator structural model, the output end of the simulated radiator structural model is connected to the input end of the simulated water pump structural model, the output end of the simulated water pump structural model is connected to the input end of the simulated battery stack structural model, and the simulated coolant structural model is used to simulate the coolant flowing through the simulated battery stack structural model, the simulated thermostat structural model, the simulated water pump structural model, and the simulated radiator structural model; A battery thermal management system model is constructed based on the heat generation power calculation model of the simulated battery stack, the temperature calculation model of the simulated battery stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow calculation model output by the simulated water pump, the heat absorption calculation model after the coolant flows through the battery stack, the coolant mass flow calculation model flowing through the simulated radiator and the structural model of the battery thermal management system.

2. The method according to claim 1, It is characterized in that The heat generation power calculation model of the simulated fuel cell stack is as follows: P heat =(U-1.254·N cell )·i·A / 1000, Among them, P heat is to simulate the heat generation power of the battery stack, U is the total output voltage, N cell is the number of single cells in the battery stack, and A is the activation area.

3. The method according to claim 1, It is characterized in that The heat dissipation calculation model of the simulated radiator is as follows: Q rad =N fan ·h rad ·A(T rad -T env ), Among them, Q rad is the heat dissipation of the simulated radiator, N fan is the number of fans, h rad is the heat transfer coefficient, A is the heat transfer area, T rad is the temperature of the simulated heat sink during operation, T env is the ambient temperature.

4. The method according to claim 1, It is characterized in that The calculation model of the heat absorption calculation model after the coolant flows through the battery stack is as follows: Q cw =C cw ·M cw (T st_out -T st_in ), Among them, Q cw is the heat absorbed by the coolant after flowing through the battery stack, C cw is the specific heat capacity of the coolant, M cw is the coolant mass flow rate, T st_in is the coolant inlet temperature of the stack, T st_out is the coolant outlet temperature of the fuel cell stack.

5. The method according to claim 1, It is characterized in that The calculation model of the coolant mass flow rate flowing through the radiator is as follows: Among them, M rad is the coolant mass flow rate flowing through the radiator, V opening is the opening of the thermostat, the value range of the opening is [0,85], N cw is the mass flow rate of the coolant; Coolant mass flow M that does not flow through the radiator and directly enters the circulating water pump module minor The calculation formula is as follows: M minor＝ M cw -M rad 。 6. The method according to claim 1, It is characterized in that The temperature calculation model of the simulated stack is as follows: Among them, C st is the specific heat capacity of the battery stack, M st is the mass of the battery stack, P heat To simulate the heat generation power of the battery stack, Q cw It is the amount of heat absorbed by the coolant after flowing through the battery stack.

7. The method according to claim 1, It is characterized in that The step of fitting the relationship between the total output voltage and current density of the target physical battery stack to obtain a calculation formula for the fitted total output voltage includes: Within a preset current density range, adjusting the current density value of the target physical battery stack, and recording the total output voltage at the corresponding current density value; The current density values ​​and the corresponding total output voltages are fitted to obtain a calculation formula for the total output voltage.

8. An electronic device comprising a memory, a processor and a computer program stored in the memory, It is characterized in that The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product comprising a computer program / instructions, It is characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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