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

Abstract

The present disclosure relates to the technical field of fuel cells, and particularly relates to a battery thermal management system modeling method, device, storage medium and computer program, the method comprising: obtaining a heat generation power calculation model of a simulated electric pile by fitting the performance of a target entity electric pile, obtaining a heat dissipation amount calculation model of a simulated heat sink by fitting the performance of a target entity heat exchanger, constructing a cooling liquid mass flow rate calculation model of a simulated water pump output, a heat absorption amount calculation model of the cooling liquid after flowing through the electric pile, and a cooling liquid mass flow rate calculation model flowing through the simulated heat sink, and comprehensively constructing each calculation model to obtain a battery thermal management system model. The disclosed modeling method can complete the construction of the model on a single modeling platform, such as using Simulink software to construct a thermal management model that is more consistent with the performance of the physical object, solving the problem that simultaneously running multiple software easily leads to a decrease in simulation speed, making it difficult for joint simulation to meet real-time requirements.

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

[0002] With the rapid development of technology, the application of Proton Exchange Membrane Fuel Cell (PEMFC) is more and more widely used. Generally, the heat generated by PEMFC is equivalent to the electric energy output, and the balance between heat generation and heat removal determines the working temperature of PEMFC, which seriously affects the performance and service life of the fuel cell. In order to make the electric pile run stably and safely for a long time, it is necessary to control its temperature in a suitable range.

[0003] AMEsim software has a professional fuel cell system model library, high integration degree, and provides rich analysis tools and practical application cases, which can realize the one-dimensional simulation model building of fuel cell thermal management system, system performance evaluation and optimization. However, the modeling ability of AMEsim software in control model building, different state switching and other aspects is insufficient, and it is slightly weak in dynamic characteristic research of complex working conditions. In order to overcome the limitations of single simulation software, the method of joint simulation 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; at the same time, Simulink is used to build a control model to realize complex control strategy and logic. Through the interface between the two software (such as S-Function of Simulink or interface module of AMEsim), real-time data exchange and synchronous simulation can be realized.

[0004] However, in the process of joint simulation, running two software at the same time and exchanging data can easily lead to a decrease in simulation speed, especially in complex model processing or real-time simulation application scenarios, because there is a delay in data exchange and synchronous control, making it difficult for joint simulation to meet real-time requirements. SUMMARY

[0005] The present disclosure provides a battery thermal management system modeling method, device, storage medium and computer program to solve the problem that running two software at the same time and exchanging data in the process of joint simulation can easily lead 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 a relationship between total output voltage and current density of the target entity stack, to obtain a fitting calculation formula of the total output voltage;

[0008] constructing a heat production power calculation model of the simulation stack according to the total output voltage, a preset current density, a preset activation area and a preset number of stack single cells;

[0009] obtaining a heat exchange coefficient of the target entity radiator, and constructing a heat dissipation amount calculation model of the simulation radiator according to the heat exchange coefficient, a preset number of fans, a preset heat exchange area and a preset ambient temperature;

[0010] constructing a cooling liquid mass flow rate calculation model of the simulation water pump output according to the relationship between the rotation speed of the water pump and the cooling liquid mass flow rate;

[0011] constructing a heat absorption amount calculation model of the cooling liquid after flowing through the stack according to a preset specific heat capacity of the cooling liquid and the cooling liquid mass flow rate output by the simulation water pump output calculation model;

[0012] constructing a temperature calculation model of the simulation stack according to the simulation stack heat production power calculation model, the cooling liquid heat absorption amount calculation model after flowing through the stack, a preset specific heat capacity of the stack and a preset mass of the stack;

[0013] constructing a cooling liquid mass flow rate calculation model of the simulation radiator according to the shunt principle of the thermostat;

[0014] constructing a structure model of the battery thermal management system, wherein the structure model comprises a simulation stack structure model, a simulation thermostat structure model, a simulation cooling liquid structure model, a simulation water pump structure model and a simulation radiator structure model, an output end of the simulation stack structure model is connected with an input end of the simulation thermostat structure model, a first output end of the simulation thermostat structure model is connected with an input end of the simulation water pump structure model, a second output end of the simulation thermostat structure model is connected with an input end of the simulation radiator structure model, an output end of the simulation radiator structure model is connected with an input end of the simulation water pump structure model, an output end of the simulation water pump structure model is connected with an input end of the simulation stack structure model, and the simulation cooling liquid structure model is used to simulate the circulation of the cooling liquid in the simulation stack structure model, the simulation thermostat structure model, the simulation water pump structure model and the simulation radiator structure model;

[0015] According to the heat production power calculation model of the simulated electric pile, the temperature calculation model of the simulated electric pile, the heat dissipation calculation model of the simulated radiator, the cooling liquid mass flow output calculation model of the simulated water pump, the heat absorption calculation model of the cooling liquid after flowing through the electric pile, the cooling liquid mass flow calculation model flowing through the simulated radiator, and the structure model of the battery thermal management system, a battery thermal management system model is constructed.

[0016] In an embodiment, the heat production power calculation model of the simulated electric pile is as follows:

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

[0018] wherein P heat is the heat production power of the simulated electric pile, U is the total output voltage, N cell is the number of electric pile single cells, and A is the activation area.

[0019] In an 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] wherein Q rad is the heat dissipation of the simulated radiator, N fan is the number of fans, h rad is the heat exchange coefficient, A is the heat exchange area, T rad is the temperature of the simulated radiator in operation, and T env is the ambient temperature.

[0022] In an embodiment, the expression of the calculation model of the heat absorption calculation model of the cooling liquid after flowing through the electric pile is as follows:

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

[0024] wherein Q cw is the heat absorption of the cooling liquid after flowing through the electric pile, C cw is the specific heat capacity of the cooling liquid, M cw is the cooling liquid mass flow, T st_in is the cooling liquid inlet temperature of the electric pile, and T st_out is the cooling liquid outlet temperature of the electric pile.

[0025] In an embodiment, the expression of the calculation model of the cooling liquid mass flow rate flowing through the radiator is as follows:

[0026]

[0027] wherein M rad is the cooling liquid mass flow rate flowing through the radiator, V opening is the opening degree of the thermostat, the opening degree ranging from 0 to 85, M cw is the cooling liquid mass flow rate.

[0028] The calculation formula of the cooling liquid mass flow rate M minor flowing through the radiator and directly into the circulating water pump module is as follows:

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

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

[0031] constructing a temperature calculation model of the simulated electric pile according to the calculation model of the heat generation power of the simulated electric pile, the calculation model of the heat absorption amount of the cooling liquid after flowing through the electric pile, a preset specific heat capacity of the electric pile, and a preset mass of the electric pile;

[0032] The step of constructing the battery thermal management system model comprises:

[0033] constructing a battery thermal management system model according to the calculation model of the heat generation power of the simulated electric pile, the temperature calculation model of the simulated electric pile, the calculation model of the heat dissipation amount of the simulated radiator, the calculation model of the cooling liquid mass flow rate output by the simulated water pump, the calculation model of the heat absorption amount of the cooling liquid after flowing through the electric pile, the calculation model of the cooling liquid mass flow rate flowing through the simulated radiator, and the structure model of the battery thermal management system.

[0034] In an embodiment, the step of fitting the relationship between the total output voltage and the current density of the target entity electric pile comprises:

[0035] adjusting the current density value of the target entity electric pile within a preset current density range, and recording the total output voltage corresponding to the current density value;

[0036] fitting each of the current density values and the corresponding total output voltages to obtain a calculation formula of 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 configured to fit a relationship between total output voltage and current density of a target entity stack to obtain a fitting calculation formula of the total output voltage;

[0039] a first construction module configured to construct a heat production power calculation model of a simulation stack according to the total output voltage, a preset current density, a preset activation area and a preset number of stack single cells;

[0040] a second construction module configured to obtain a heat exchange coefficient of a target entity radiator, and construct a heat dissipation calculation model of a simulation radiator according to the heat exchange coefficient, a preset number of fans, a preset heat exchange area and a preset ambient temperature;

[0041] a third construction module configured to construct a cooling liquid mass flow rate calculation model of a simulation water pump output according to a relationship between a rotation speed of the water pump and the cooling liquid mass flow rate;

[0042] a fourth construction module configured to construct a heat absorption calculation model of the cooling liquid after flowing through the stack according to a preset specific heat capacity of the cooling liquid and the cooling liquid mass flow rate output by the simulation water pump output calculation model;

[0043] a fifth construction module configured to construct a temperature calculation model of the simulation stack according to the heat production power calculation model of the simulation stack, the heat absorption calculation model of the cooling liquid after flowing through the stack, a preset specific heat capacity of the stack and a preset mass of the stack;

[0044] a sixth construction module configured to construct a cooling liquid mass flow rate calculation model of a simulation thermostat according to a shunt principle of the thermostat;

[0045] a comprehensive construction module configured to construct a structure model of a battery thermal management system, wherein the structure model comprises a simulation stack structure model, a simulation thermostat structure model, a simulation cooling liquid structure model, a simulation water pump structure model and a simulation radiator structure model, an output end of the simulation stack structure model is connected with an input end of the simulation thermostat structure model, a first output end of the simulation thermostat structure model is connected with an input end of the simulation water pump structure model, a second output end of the simulation thermostat structure model is connected with an input end of the simulation radiator structure model, an output end of the simulation radiator structure model is connected with an input end of the simulation water pump structure model, an output end of the simulation water pump structure model is connected with an input end of the simulation stack structure model, and the simulation cooling liquid structure model is configured to simulate the cooling liquid flowing through the simulation stack structure model, the simulation thermostat structure model, the simulation water pump structure model and the simulation radiator structure model;

[0046] According to the heat production power calculation model of the simulated electric pile, the temperature calculation model of the simulated electric pile, the heat dissipation calculation model of the simulated heat sink, the cooling liquid mass flow output calculation model of the simulated water pump, the heat absorption calculation model of the cooling liquid flowing through the electric pile, the cooling liquid mass flow calculation model flowing through the simulated heat sink, and the structure model of the battery thermal management system, a battery thermal management system model is constructed.

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

[0048] In a fourth aspect, the present disclosure provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the method of the above aspect.

[0049] In a fifth aspect, the present disclosure provides a computer program product comprising a computer program / instruction, wherein the computer program is executed by a processor to implement the steps of the method of the above aspect.

[0050] The battery thermal management system modeling method, device, storage medium, and computer program provided by the present disclosure can more accurately reflect the actual working state of the electric pile and the heat exchanger by fitting the performance of the target electric pile and the heat exchanger, thereby improving the accuracy of the simulation model. At the same time, the present disclosure considers multiple key components of the battery thermal management system, including the electric pile, the heat sink, the water pump, the cooling liquid, and the thermostat, and constructs a corresponding simulation model for each component. This comprehensive modeling approach can more comprehensively reflect the complexity and dynamics of the battery thermal management system, improving the reliability of the simulation. By simulating the operation process of the battery thermal management system, key parameters such as heat production power, heat dissipation, cooling liquid mass flow, and heat absorption under different working conditions can be predicted, which helps to identify and solve potential thermal management problems in advance, optimize system design and operation strategies, and improve system safety and efficiency. The modeling method of 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 better matches the performance of the actual object, solving the problem of simultaneous operation of two software and data exchange in the prior art, which easily leads to a decrease in simulation speed, making it difficult for joint simulation to meet real-time requirements. BRIEF DESCRIPTION OF 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 flowchart of a battery thermal management system modeling method according to an embodiment of the present disclosure is shown in the figure;

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

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

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

[0056] In order to make the person skilled in the art better understand the technical solutions of the present disclosure, and to fully understand and implement the implementation process of the present disclosure how to apply technical means to solve technical problems and achieve corresponding technical effects, the technical solutions in the embodiments of the present disclosure will be described clearly and completely in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, not all. The embodiments of the present disclosure and various features in the embodiments can be combined with each other without conflict, and the technical solutions formed thereby are all within the protection scope of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor shall be within the scope of protection of the present disclosure.

[0057] It should be noted that the terms "first", "second" and the like in the specification and claims of the present disclosure and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

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

[0059] Embodiment one

[0060] Figure 1 A flowchart of a battery thermal management system modeling method provided for an embodiment of the present disclosure. As shown in the figure, Figure 1 A battery thermal management system modeling method, comprising:

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

[0062] In this embodiment, after the equipment and experimental environment required for fitting experiments are set up, the current density value is gradually changed in the selected current density range, and the total output voltage under the corresponding conditions is recorded. Each current density point can be measured multiple times and averaged to improve the accuracy and reliability of the data. Then, the experimental data obtained by measurement are sorted to form a corresponding relationship table or graph of current density and 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. according to actual needs, and the specific place is not limited.

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

[0064]

[0065] Where i is the current density, U is the total output voltage, a, b, c, and d are constants, and the values of a, b, c, and d obtained by fitting the characteristics of different entity stacks are different.

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

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

[0068] P elec = U·i·A / 1000,

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

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

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

[0072] Where P heat is the heat production power of the simulated stack, and N cell is the number of stack single cells.

[0073] It can be understood that a large amount of heat is generated during the operation of the stack, which is related to the output power, working efficiency and internal chemical reaction of the stack and many other factors. By fitting the heat generation power calculation model, the heat generation characteristics of the stack under different working conditions can be more accurately described, thereby improving the accuracy of the stack model.

[0074] In step 130, the heat exchange coefficient of the target entity radiator is obtained, and a heat dissipation amount calculation model of the simulated radiator is constructed according to the heat exchange coefficient, a preset number of fans, a preset heat exchange area and a preset environment temperature.

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

[0076] Number of fans: Fans are used to increase air flow, thereby improving the heat dissipation effect. The more the number of fans, the greater the air volume and the higher the heat dissipation efficiency; Heat exchange area: The larger the effective heat dissipation area of the radiator, the more heat can be exchanged; Environment temperature: The environment temperature is an important external factor affecting the heat dissipation effect of the radiator. The higher the environment temperature, the more heat the radiator needs to dissipate, and the difficulty of heat dissipation also increases accordingly.

[0077] In this embodiment, the heat dissipation amount calculation model of the simulated radiator is constructed by considering the heat exchange coefficient, the number of fans, the heat exchange area and the environment temperature, which can help to more accurately represent the heat dissipation performance of the radiator.

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

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

[0080] wherein Q rad is the heat dissipation amount of the simulated radiator, N fan is the number of fans, h rad is the heat exchange coefficient, A is the heat exchange area, T rad is the temperature of the simulated radiator in operation, and T env is the environment temperature.

[0081] Step 140, according to the relationship between the rotation speed of the water pump and the mass flow of the cooling liquid, a calculation model of the mass flow of the cooling liquid output by the water pump is constructed;

[0082] The rotation speed of the water pump determines the speed of the impeller rotation, and further affects the speed of the cooling liquid being sucked in and discharged. Generally, the higher the rotation speed of the water pump, the greater the amount of cooling liquid (or the mass flow of the cooling liquid) passing through the water pump per unit time.

[0083] Based on the relationship between the rotation speed of the water pump and the mass flow, a calculation model of the mass flow of the cooling liquid output by the water pump is constructed, so that different mass flows of the cooling liquid can be output by inputting different rotation speed values.

[0084] Step 150, according to the preset specific heat capacity of the cooling liquid and the mass flow of the cooling liquid output by the calculation model of the mass flow of the cooling liquid output by the water pump, a calculation model of the heat absorption of the cooling liquid after flowing through the stack is constructed;

[0085] For the fuel cell system, hydrogen and oxygen undergo oxidation-reduction reaction in the stack through catalyst, and then generate electric energy, about half of which is generated in the form of heat, and the efficient operation temperature range of the stack is generally 60℃-80℃. In order to avoid the influence of over-temperature on the stability and durability of the stack, the circulating water pump must be used to take away the heat generated by the stack through the cooling liquid, and then the cooling liquid and air are exchanged through the radiator, so as to take away the heat in the cooling liquid. The cooling liquid after being cooled by the radiator reenters the stack for circulation.

[0086] According to the principle of thermodynamics, the heat absorbed by the cooling liquid can be calculated by the following formula:

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

[0088] Wherein, Q cw is the heat absorption of the cooling liquid after flowing through the stack, C cw is the specific heat capacity of the cooling liquid, M cw is the mass flow of the cooling liquid, T st_in is the inlet temperature of the cooling liquid of the stack, and T st_out is the outlet temperature of the cooling liquid of the stack.

[0089] Step 160, according to the calculation model of the heat generation power of the stack, the calculation model of the heat absorption of the cooling liquid after flowing through the stack, the preset specific heat capacity of the stack and the preset mass of the stack, a temperature calculation model of the stack is constructed;

[0090] In this embodiment, based on 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 based on four main parameters: simulation radiator heat dissipation calculation model, cooling liquid heat absorption calculation model after flowing through the stack, preset stack specific heat capacity, and preset stack mass.

[0091] The temperature change of the stack depends on its heat generation, heat dissipation, and its own heat capacity. The heat generation is given by the simulation stack heat generation power calculation model, and the heat dissipation is estimated by the process of cooling liquid flowing through the stack and then being dissipated by the radiator (using the simulation radiator heat dissipation calculation model and the cooling liquid heat absorption calculation model after flowing through the stack). The specific heat capacity and mass of the stack determine the magnitude of the temperature change under a given heat change.

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

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

[0094]

[0095] where C st is the specific heat capacity of the stack, M st is the mass of the stack, P heat is the heat generation power of the simulation stack, Q cw is the heat absorption of the cooling liquid after flowing through the stack.

[0096] Step 170, according to the flow splitting principle of the thermostat, a cooling liquid mass flow calculation model flowing through the simulation radiator is constructed;

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

[0098] In one embodiment, the expression of the cooling liquid mass flow calculation model flowing through the radiator is as follows:

[0099]

[0100] where M radV is the mass flow rate of the cooling liquid flowing through the radiator, opening M is the opening degree of the thermostat, the opening degree ranging from [0, 85], cw V is the mass flow rate of the cooling liquid.

[0101] M is the mass flow rate of the cooling liquid flowing through the radiator and directly into the circulating water pump module minor The calculation formula of M 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 immediately cooled. At this time, the opening degree of the thermostat is 0, the cooling liquid does not flow through the radiator, and the temperature of the cooling liquid will continue to rise during this process. As the output power of the stack continues to rise, the cooling liquid temperature continues to rise, and in order to avoid overheating, the thermostat needs to be turned on to maintain the cooling liquid temperature within a suitable range through the radiator. Therefore, during this stage of change in the opening degree of the thermostat, the temperature of the cooling liquid that does not flow through the radiator is different from the temperature of the cooling liquid that flows through the radiator, and the two are mixed and then enter the stack. When the opening degree of the thermostat reaches 85, it indicates that the cooling liquid is flowing through the radiator at this time, and the cooling liquid is rapidly cooled through the radiator.

[0104] Step 180, constructing a structure model of the battery thermal management system, wherein the structure model includes a simulated stack structure model, a simulated thermostat structure model, a simulated cooling liquid structure model, a simulated water pump structure model, and a simulated radiator structure model, an output end of the simulated stack structure model is connected with an input end of the simulated thermostat structure model, a first output end of the simulated thermostat structure model is connected with an input end of the simulated water pump structure model, a second output end of the simulated thermostat structure model is connected with an input end of the simulated radiator structure model, an output end of the simulated radiator structure model is connected with an input end of the simulated water pump structure model, an output end of the simulated water pump structure model is connected with an input end of the simulated stack structure model, and the simulated cooling liquid structure model is used to simulate the circulation of the cooling liquid among the simulated stack structure model, the simulated thermostat structure model, the simulated water pump structure model, and the simulated radiator structure model.

[0105] According to the heat generation power calculation model of the simulated stack, the temperature calculation model of the simulated stack, the heat dissipation calculation model of the simulated radiator, the cooling liquid mass flow rate calculation model of the simulated water pump output, the heat absorption calculation model of the cooling liquid after flowing through the stack, the cooling liquid mass flow rate calculation model of flowing through the simulated radiator, and the structure model of the battery thermal management system, a battery thermal management system model is constructed.

[0106] In this example, as shown in Figure 2 In the normal load process of the fuel cell system, the initial temperature of the cooling liquid is not high. In order to quickly heat the stack, the cooling liquid flow path is controlled by the thermostat, so that the cooling liquid does not flow through the radiator. At this time, the thermostat is in the closed stage, and the flow path of the cooling liquid is circulating water pump→stack→thermostat→circulating water pump, which is called small circulation. As the power of the stack increases, the temperature of the cooling liquid gradually rises. When the temperature reaches a certain temperature, the thermostat opens, and as the opening degree increases, the small circulation flow gradually decreases, and the flow through the radiator gradually increases. At this time, the cooling liquid flows through the small circulation and the radiator at the same time. When the thermostat is fully opened, the flow path of the cooling liquid is circulating water pump→stack→thermostat→radiator→circulating water pump, which is called large circulation. At this time, the temperature of the cooling liquid will also tend to be stable, and the mutual cooperation of the components of the thermal management system ensures the efficient operation of the stack.

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

[0108] In summary, the battery thermal management system modeling method provided by the present disclosure can more accurately reflect the actual working state of the stack and the heat exchanger by fitting the performance of the target entities, thereby improving the accuracy of the simulation model. At the same time, the present disclosure considers multiple key components of the battery thermal management system, including the stack, the radiator, the water pump, the cooling liquid and the thermostat, and constructs a corresponding simulation model 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, the key parameters such as heat generation power, heat dissipation, cooling liquid mass flow 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 strategy, and improve the safety and efficiency of the system. The modeling method of the present disclosure can complete the model building on a single modeling platform, such as using Simulink software to build a thermal management model that is more consistent with the performance of the actual object, solving the problem that the existing technology simultaneously runs two software and exchanges data, which easily leads to a decrease in simulation speed, making it difficult for joint simulation to meet real-time requirements.

[0109] In an embodiment, the method further comprises: constructing a temperature calculation model of the simulated stack according to a heat production power calculation model of the simulated stack, a heat absorption calculation model of the cooling liquid after flowing through the stack, a preset specific heat capacity of the stack, and a preset mass of the stack; and the step of constructing the battery thermal management system model comprises: constructing the battery thermal management system model according to the heat production power calculation model of the simulated stack, the temperature calculation model of the simulated stack, a heat dissipation calculation model of the simulated radiator, a cooling liquid mass flow calculation model of the simulated water pump output, the heat absorption calculation model of the cooling liquid after flowing through the stack, a cooling liquid mass flow calculation model of the simulated radiator, and a structure model of the battery thermal management system.

[0110] Embodiment Two

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

[0112] In this embodiment, a stack model, a circulating water pump model, a cooling liquid 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 steps are included.

[0113] 2.1. Construction of the stack model

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

[0115]

[0116] wherein 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 stack can be expressed as:

[0118] P elec = U·i·A / 1000

[0119] wherein P elec is the output power of the stack, and A is the active area.

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

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

[0122] wherein P heat is the heat production power of the simulated stack, and N cell is the number of single cells of the stack.

[0123] 2.2. Construction of the cooling liquid model

[0124] Generally, the heat dissipated by the stack to the environment in the form of convective heat transfer and radiative heat transfer is no more than 5% of the total heat generation, and this part of heat can be ignored in the process of heat balance analysis and modeling, only considering the heat taken away by the cooling liquid from the stack, and the difference between the total heat generation and the heat absorbed by the cooling liquid is manifested as the rise of the stack temperature.

[0125] The heat absorbed by the cooling liquid flowing through the stack can be expressed as:

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

[0127] Wherein, Q cw is the heat absorbed by the cooling liquid after flowing through the stack, C cw is the specific heat capacity of the cooling liquid, M cw is the mass flow rate of the cooling liquid, T st_in is the inlet temperature of the cooling liquid of the stack, and T st_out is the outlet temperature of the cooling liquid of the stack.

[0128] According to the heat balance relationship of the stack, while not considering the temperature uniformity inside the stack, the following heat balance equation can be obtained:

[0129]

[0130] Wherein, C st is the specific heat capacity of the stack, M st is the mass of the stack, and T st is the temperature of the stack.

[0131] Further, the temperature calculation model of the 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 the speed have the following corresponding relationship:

[0135]

[0136] Wherein, n0, M0 are the speed of the water pump and the corresponding mass flow rate of the cooling liquid under a certain working condition, and correspondingly, n1, M1 are the speed of the water pump and the mass flow rate of the cooling liquid under another working condition.

[0137] 2.4, radiator model

[0138] In the fuel cell thermal management system, with the rotation of the radiator fan, the air and the radiator fins are in convective heat transfer, the specific equation is as follows:

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

[0140] Wherein, 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 in operation, T env is the ambient temperature.

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

[0142] According to the heat balance relationship, the heat absorbed by the air is equal to the heat dissipated by the cooling liquid through the radiator, so the outlet temperature of the cooling liquid of the radiator can be derived as:

[0143]

[0144] Wherein, T rad_out is the outlet temperature of the cooling liquid of the radiator, T rad_in is the inlet temperature of the cooling liquid of the radiator, M rad is the mass flow rate of the cooling liquid flowing through the radiator.

[0145] In the system modeling process of this embodiment, the heat loss of the cooling liquid flowing through the system pipeline is ignored, therefore, the outlet cooling liquid temperature of the stack is equal to the inlet cooling liquid 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, 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] Wherein, M rad is the mass flow rate of the cooling liquid 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's easy to see that as the thermostat opening increases, the total flow rate of the circulating water pump equals the sum of the flow rates of the small and large circulation loops. When the thermostat is fully open, all the coolant flows through the radiator, that is:

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

[0153] Among them, M minor This refers to the mass flow rate of coolant that enters the circulating water pump module directly without passing through the radiator.

[0154] As the fuel cell stack's output power increases, the coolant temperature rises continuously. To prevent overheating, the thermostat needs to be opened to maintain the coolant temperature within a suitable range through the radiator. Therefore, during the phase of thermostat opening change, the coolant temperature in the small circulation loop differs from the coolant temperature flowing through the radiator. The two mix before entering the fuel cell stack, and at this point, the coolant temperature reflects the fuel cell stack inlet temperature, i.e., T. st_in Based on the principles of heat transfer, the following equation can be obtained by analyzing the above process:

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

[0156] Expanding and deriving the above formula, we can obtain the following formula for calculating the coolant inlet temperature of the fuel cell stack:

[0157]

[0158] 2.6 Run the model and observe the temperature changes.

[0159] After setting up the above models and setting the initial operating parameters, such as water pump speed, thermostat opening, and ambient temperature, run the models. As the running time increases, the temperature of the fuel cell stack, the inlet / outlet temperature of the fuel cell stack, and the inlet / outlet temperature of the radiator will change.

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

[0161] Embodiment three

[0162] On the basis of the above embodiment, as Figure 3 indicated, the embodiment provides a battery thermal management system modeling device, including:

[0163] The fitting module 310 is configured to fit the relationship between the total output voltage and the current density of the target entity stack to obtain a calculation formula of the fitted total output voltage.

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

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

[0166] The third construction module 340 is configured to construct a cooling liquid mass flow rate calculation model of the simulated water pump output according to the relationship between the rotating speed of the water pump and the cooling liquid mass flow rate.

[0167] The fourth construction module 350 is configured to construct a heat absorption calculation model of the cooling liquid after flowing through the stack according to a preset specific heat capacity of the cooling liquid and the cooling liquid mass flow rate output by the simulated water pump output cooling liquid mass flow rate calculation model.

[0168] The fifth construction module 360 is configured to construct a temperature calculation model of the simulated stack according to the simulated stack heat generation power calculation model, the heat absorption calculation model of the cooling liquid after flowing through the stack, a preset specific heat capacity of the stack, and a preset mass of the stack.

[0169] The sixth construction module 370 is configured to construct a cooling liquid mass flow rate calculation model flowing through the simulated radiator according to the shunt principle of the thermostat.

[0170] The comprehensive construction module 380 is configured to construct a structural model of the battery thermal management system, wherein the structural model comprises a simulated 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, an output end of the simulated stack structural model is connected to an input end of the simulated thermostat structural model, a first output end of the simulated thermostat structural model is connected to an input end of the simulated water pump structural model, a second output end of the simulated thermostat structural model is connected to an input end of the simulated radiator structural model, an output end of the simulated radiator structural model is connected to an input end of the simulated water pump structural model, an output end of the simulated water pump structural model is connected to an input end of the simulated stack structural model, and the simulated coolant structural model is configured to simulate the flow of coolant through the simulated stack structural model, the simulated thermostat structural model, the simulated water pump structural model, and the simulated radiator structural model.

[0171] According to the heat generation power calculation model of the simulated stack, the temperature calculation model of the simulated stack, the heat dissipation calculation model of the simulated radiator, the coolant mass flow rate calculation model of the simulated water pump output, the heat absorption calculation model of the coolant flowing through the stack, the coolant mass flow rate calculation model of the simulated radiator, and the structural model of the battery thermal management system, a battery thermal management system model is constructed.

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

[0173] An adjusting unit is configured to adjust the current density value of the target physical stack within a preset current density range, and record the total output voltage corresponding to the current density value.

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

[0175] The specific limitations of the battery thermal management system modeling device can be referred to the limitations of the battery thermal management system modeling method described above, which will not be repeated here. Each unit in the above battery thermal management system modeling device can be realized by software, hardware, and combinations thereof, in whole or in part. The above units can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to each unit.

[0176] Embodiment four

[0177] On the basis of the above embodiments, an electronic device is provided, 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 embodiments.

[0178] In some embodiments of the present embodiment, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the method in the above-mentioned embodiments.

[0179] In some embodiments of the present embodiment, a computer program product is provided, and the computer program product includes a computer program / instruction, and the computer program is executed by a processor to implement the steps of the method in the above-mentioned embodiments.

[0180] The processor can include, but is not limited to, for example, one or more processors or microprocessors, etc. Each processor can 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 elements for executing the methods in the above-mentioned embodiments.

[0181] The computer readable storage medium can be implemented by any type of volatile or non-volatile storage devices or a combination thereof, and the computer readable storage medium can include, but is not limited to, for example, a Random Access Memory (RAM), a Read Only Memory (ROM), a flash memory, an EPROM memory, an EEPROM memory, a register, a computer storage medium (such as a hard disk, a floppy disk, a solid state disk, a removable disk, a Blu-ray disk, etc.).

[0182] The computer readable storage medium can also store at least one computer executable program / instruction, such as computer readable instructions. 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 can include, for example, a Random Access Memory (RAM) and / or a cache memory, etc. The computer readable storage medium can include, for example, a Read Only Memory (ROM), a hard disk, a flash memory, etc. For example, the non-transitory computer readable storage medium can be connected to a computing device, such as a computer, and then, in the case that the computing device runs the computer readable instructions stored on the computer readable storage medium, the various methods as described above can be performed.

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

[0184] The processor can communicate with an external device via a wired or wireless network through the I / O bus.

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

[0186] In the embodiments provided in the present disclosure, it should be understood that the disclosed apparatus and method can also be implemented in other ways. The apparatus embodiments described above are only illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible implementation architectures, functions and operations of the apparatus, method and computer program product according to the embodiments of the present disclosure. In this regard, each block in the flowcharts or block diagrams can represent a module, a program segment or a part of code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur in different orders from those noted in the accompanying drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and the combination of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0187] It should be noted that in the present disclosure, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element limited by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0188] Although the disclosed embodiments have been fully described above with reference to the attachments, it is to be understood that various changes can be made and equivalents can be substituted for elements thereof with out departing from the scope of the disclosure as set forth in the claims. Further, many modifications can be made to adapt a particular situation to the teachings of the disclosure without departing from the central inventive concept described herein. Therefore, it is intended that the disclosure not be limited to the particular embodiment disclosed as the best or only means for carrying out the disclosure.

Claims

1. A battery thermal management system modeling method, characterized by, The method comprises the following steps: fitting a relationship between total output voltage and current density of a target entity stack to obtain a calculation formula of the fitted total output voltage; constructing a heat generation power calculation model of a simulated stack according to the total output voltage, a preset current density, a preset activation area, and a preset number of stack single cells; obtaining a heat exchange coefficient of a target entity radiator, and constructing a heat dissipation amount calculation model of a simulated radiator according to the heat exchange coefficient, a preset number of fans, a preset heat exchange area, and a preset ambient temperature; constructing a cooling liquid mass flow rate calculation model of a simulated water pump output according to a relationship between a rotational speed of the water pump and the cooling liquid mass flow rate; constructing a heat absorption amount calculation model of the cooling liquid after flowing through the stack according to a preset specific heat capacity of the cooling liquid and the cooling liquid mass flow rate output by the cooling liquid mass flow rate calculation model of the simulated water pump output; constructing a temperature calculation model of the simulated stack according to the heat generation power calculation model of the simulated stack, the heat absorption amount calculation model of the cooling liquid after flowing through the stack, a preset specific heat capacity of the stack, and a preset mass of the stack; constructing a cooling liquid mass flow rate calculation model of the simulated radiator according to a shunt principle of a thermostat; constructing a structure model of the battery thermal management system, wherein the structure model comprises a simulated stack structure model, a simulated thermostat structure model, a simulated cooling liquid structure model, a simulated water pump structure model, and a simulated radiator structure model, an output end of the simulated stack structure model is connected with an input end of the simulated thermostat structure model, a first output end of the simulated thermostat structure model is connected with an input end of the simulated water pump structure model, a second output end of the simulated thermostat structure model is connected with an input end of the simulated radiator structure model, an output end of the simulated radiator structure model is connected with an input end of the simulated water pump structure model, an output end of the simulated water pump structure model is connected with an input end of the simulated stack structure model, and the simulated cooling liquid structure model is used for simulating the cooling liquid flowing through the simulated stack structure model, the simulated thermostat structure model, the simulated water pump structure model, and the simulated radiator structure model; constructing a battery thermal management system model according to the heat generation power calculation model of the simulated stack, the temperature calculation model of the simulated stack, the heat dissipation amount calculation model of the simulated radiator, the cooling liquid mass flow rate calculation model of the simulated water pump output, the heat absorption amount calculation model of the cooling liquid after flowing through the stack, the cooling liquid mass flow rate calculation model of the simulated radiator, and the structure model of the battery thermal management system.

2. The method of claim 1, wherein, The heat generation power calculation model of the simulated stack is as follows: P heat = (U - 1.254 · N cell ) · i · A / 1000, where P is the power output of the simulated stack, U is the total output voltage, N is the number of cells in the stack, and A is the active area. heat where P is the power output of the simulated stack, U is the total output voltage, N is the number of cells in the stack, and A is the active area. cell where P is the power output of the simulated stack, U is the total output voltage, N is the number of cells in the stack, and A 3. The method of claim 1, wherein, The heat dissipation amount calculation model of the simulated radiator is as follows: Q rad = N fan · h rad · A(T rad - T env ), Wherein, Q rad is the heat dissipation of the simulated radiator, N fan is the number of fans, h rad is the heat exchange coefficient, A is the heat exchange area, T rad is the temperature of the simulated radiator in operation, T env is the ambient temperature.

4. The method of claim 1, wherein, The heat absorption amount calculation model of the cooling liquid after flowing through the stack is as follows: Q cw = C cw · M cw (T st_out -T st_in ), where Q cw is the heat absorbed by the coolant after flowing through the stack, C cw is the specific heat capacity of the coolant, M cw is the mass flow rate of the coolant, T st_in is the coolant inlet temperature of the stack, T st_out is the coolant outlet temperature of the stack.

5. The method of claim 1, wherein, The cooling liquid mass flow rate calculation model of the simulated radiator is as follows: wherein M rad is the mass flow rate of the coolant flowing through the radiator, V opening is the opening of the thermostat, the opening taking values in the range [0, 85], N cw is the mass flow rate of the coolant; Mass flow rate M of coolant that does not pass through the radiator and goes directly into the circulating water pump module minor The calculation formula is as follows: M minor＝ M cw -M rad .

6. The method of claim 1, wherein, The temperature calculation model of the simulated stack is as follows: where C st is the specific heat capacity of the stack, M st is the mass of the stack, P heat is the heat generation power of the simulated stack, Q cw is the heat absorption of the cooling liquid after flowing through the stack.

7. The method of claim 1, wherein, The step of fitting a relationship between total output voltage and current density of a target entity stack to obtain a calculation formula of the fitted total output voltage comprises the following steps: adjusting a current density value of the target entity stack in a preset current density range, and recording a total output voltage corresponding to the current density value; fitting each of the current density values and each of the corresponding total output voltages to obtain a calculation formula of the total output voltage.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program, when executed by the processor, is arranged to perform the method of any one of claims 1 to 7. The processor executes the computer program to implement the steps of the method of any one of claims 1 to 7.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by the processor, implements the steps of the method of any one of claims 1 to 7.

10. A computer program product comprising computer programs / instructions, characterized in that, The computer program, when executed by the processor, implements the steps of the method of any one of claims 1 to 7. The computer program, when executed by the processor, implements the steps of the method of any one of claims 1 to 7.

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