Battery pack thermal runaway simulation method, battery pack thermal runaway simulation system and storage medium

Abstract

The invention relates to the technical field of batteries, and discloses a battery pack thermal runaway simulation method, a battery pack thermal runaway simulation system and a storage medium, and the method comprises the steps: carrying out the heat exchange analysis of parts in a battery pack, and detecting and determining a self-heating target single battery; then, according to the established relationship between the calorific value and the gas mass flow of the target single battery and the temperature of the target single battery, rapid and accurate simulation of the thermal runaway of the battery pack can be realized, and the problem that equation parameters are difficult to solve in the prior art is avoided, so that the thermal runaway simulation time is shortened, and the simulation efficiency is improved. The experiment cost in the design and research and development stage is reduced, and the new energy automobile and the energy storage technology can be promoted to develop in the safer and more reliable direction.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery pack thermal runaway simulation method, a battery pack thermal runaway simulation system and a storage medium. Background Art

[0002] As a core component in the field of new energy vehicles and energy storage, the safety performance of power batteries is becoming increasingly important, especially in preventing battery thermal runaway, which has become a focus of attention both inside and outside the industry.

[0003] In the early stages of product development and design, it is often impractical to directly conduct thermal runaway experiments on battery packs due to the high cost of mold development and strict time constraints. Therefore, it is particularly important to simulate the thermal runaway process of battery packs with advanced simulation technology and conduct detailed evaluation and optimization in the product design stage. This not only helps to identify potential risks in advance, but also significantly reduces the cost of later testing and corrections, and accelerates the product launch process.

[0004] At present, the common method for simulating thermal runaway of battery packs is to build a thermal runaway model based on the Arrhenius equation by carefully analyzing the parameters of each chemical reaction stage inside the battery pack. However, this method faces significant challenges: in the actual thermal runaway process of the battery, the key reactions (such as the decomposition of the SEI film, the reaction between the negative electrode and the electrolyte, the reaction between the positive electrode and the electrolyte, and the decomposition of the electrolyte itself) do not strictly follow a certain sequence, but may occur simultaneously, which makes it extremely complex and difficult to accurately solve the parameters of each reaction equation.

[0005] Therefore, it is necessary to improve the existing technology. Summary of the invention

[0006] The present invention provides a battery pack thermal runaway simulation method, a battery pack thermal runaway simulation system and a storage medium to solve the problem of thermal runaway simulation difficulties in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a battery pack thermal runaway simulation method, comprising:

[0009] S101, performing heat exchange analysis on components in the battery pack;

[0010] S102, detecting the temperature of the single cells in the battery pack, and determining whether there is a target single cell, wherein the target single cell has a temperature reaching the self-heating starting temperature If not, then return to execute S101, if yes, then execute S103;

[0011] S103: Determine the heat value corresponding to the target single cell at the current temperature according to the first setting strategy. , to be loaded into the heat exchange analysis; the first setting strategy is based on a functional relationship or interpolation calculation;

[0012] S104: Determine whether the current temperature of the target single cell reaches the thermal runaway gas generation temperature. ; If not, return to execute S101, if yes, execute S105;

[0013] S105: Determine the gas mass flow rate corresponding to the target single cell at the current temperature according to the second setting strategy. , to be loaded into the heat exchange analysis; the second setting strategy is based on a functional relationship or interpolation calculation; then S106 is executed;

[0014] S106, checking whether the set cutoff condition is met; if not, returning to execute S101, if so, executing S107;

[0015] S107, simulation ends.

[0016] Furthermore, in the battery pack thermal runaway simulation method, before S101, the method further includes:

[0017] When performing ARC testing on a single cell, obtain the self-heating starting temperature of the single cell and thermal runaway gas production temperature .

[0018] Further, in the battery pack thermal runaway simulation method, S106 specifically includes:

[0019] The total calorific value of the target single cell at different temperatures is calculated and determined, and compared with the preset calorific value. If the total calorific value of the target single cell reaches the preset calorific value, the cutoff condition is met, wherein the preset calorific value is obtained by the total calorific value of the single cell through an ARC test.

[0020] Further, in the battery pack thermal runaway simulation method, when the first setting strategy is based on a functional relationship, S103 specifically includes:

[0021] Get the temperature and heat of a single battery The functional relationship between the temperature and heat generation of the single cell The functional relationship between them is expressed by the following formula:

[0022] ,

[0023] in, is the heat generated by the target single cell, and T is the current temperature of the target single cell;

[0024] The temperature and heat generation of the single battery The functional relationship between them is determined by the ARC test according to the following formula to determine the heating power of the single battery. get:

[0025] ;

[0026] in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

[0027] Further, in the battery pack thermal runaway simulation method, when the first setting strategy is based on interpolation calculation, S103 specifically includes:

[0028] Obtain known data points of the single cell, including the temperature of the single cell and the corresponding calorific value ;

[0029] Based on the known data points, the calorific value corresponding to the target single battery at the current temperature is calculated by interpolation method. ;

[0030] The known data points of the single cell are tested by ARC to determine the heating power of the single cell according to the following formula: get:

[0031] ;

[0032] in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

[0033] Further, in the battery pack thermal runaway simulation method, when the second setting strategy is based on a functional relationship, S105 specifically includes:

[0034] Obtain the temperature and gas mass flow rate of the single cell The functional relationship between the temperature of the single cell and the gas mass flow rate The functional relationship between them is expressed by the following formula:

[0035] ,

[0036] in, is the gas mass flow rate of the target single cell, T is the current temperature of the target single cell;

[0037] Wherein, the temperature of the single cell and the gas mass flow rate The functional relationship between them is obtained through ARC test according to the following formula:

[0038] ;

[0039] in, is the weighing mass of the gas, Testing time for ARC.

[0040] Further, in the battery pack thermal runaway simulation method, when the second setting strategy is based on interpolation calculation, S105 specifically includes:

[0041] Acquire known data points of the single cell, the known data points including the temperature of the single cell and the corresponding gas mass flow rate ;

[0042] Based on the known data points, the gas mass flow rate corresponding to the target single cell at the current temperature is calculated by interpolation method. ;

[0043] The known data points of the single cell are calculated by the ARC test according to the following formula:

[0044] ;

[0045] in, is the weighing mass of the gas, For ARC test time, each Corresponding to the temperature of one of the target single cells.

[0046] Furthermore, in the battery pack thermal runaway simulation method, the preset heating value is obtained by the following formula:

[0047] ;

[0048] in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

[0049] In a second aspect, the present invention provides a battery pack thermal runaway simulation system, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the battery pack thermal runaway simulation method provided in the first aspect is implemented.

[0050] In a third aspect, the present invention provides a storage medium comprising computer executable instructions, wherein the computer executable instructions are executed by a computer processor to implement the battery pack thermal runaway simulation method provided in the first aspect above.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention provides a battery pack thermal runaway simulation method, a battery pack thermal runaway simulation system and a storage medium. By performing heat exchange analysis on the components in the battery pack and detecting and determining the target single cell that generates self-heat, a rapid and accurate simulation of the thermal runaway of the battery pack can be achieved based on the established relationship between the calorific value and gas mass flow rate of the target single cell and the temperature of the target single cell. The problem of difficulty in solving equation parameters in the prior art is avoided, which is beneficial to shortening the time of thermal runaway simulation, reducing the experimental cost in the design and development stage, and helping to promote the development of new energy vehicles and energy storage technologies in a safer and more reliable direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It is a flow chart of a battery pack thermal runaway simulation method provided in the first embodiment of the present invention;

[0055] Figure 2 It is a schematic diagram of the schematic diagram of the change of the temperature of the single cell ARC test over time mentioned in the first embodiment of the present invention;

[0056] Figure 3 The heat generated by thermal runaway of the single cell mentioned in the first embodiment of the present invention Schematic diagram of temperature change;

[0057] Figure 4 is a schematic diagram of the relationship between the gas mass flow rate and the temperature of the single cell mentioned in the first embodiment of the present invention;

[0058] Figure 5It is a structural schematic diagram of a battery pack thermal runaway simulation system provided in Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0059] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0060] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0061] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0062] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0063] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0064] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0065] In this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0066] Embodiment 1

[0067] Please refer to Figure 1 , is a flow chart of a battery pack thermal runaway simulation method provided in Embodiment 1 of the present invention, which is applicable to the scenario of thermal runaway simulation of a battery pack during the product design stage. The method specifically comprises the following steps:

[0068] S101. Perform heat exchange analysis on components in the battery pack.

[0069] It should be noted that this step aims to analyze in detail the heat exchange process between the various components inside the battery pack, and to lay a solid foundation for subsequent temperature monitoring and thermal runaway simulation by accurately depicting the heat transfer path and efficiency inside the battery pack.

[0070] Furthermore, in other implementations of this embodiment, step S101 may be further refined to include the following contents:

[0071] (1) Conduct heat exchange analysis on components in the battery pack; heat exchange modes include heat conduction, heat convection and heat radiation;

[0072] (2) Heat conduction refers to the process of heat transfer through molecular vibration and collision inside a substance. In a battery pack, heat conduction mainly occurs between single cells and cooling plates, single cells and thermally conductive silicone and other solid components. Heat conduction is expressed by the following formula:

[0073] ;

[0074] in, For time, is the thermal conductivity, is the density, is the specific heat capacity, is the heat of the single battery, , , is the grid discrete unit coordinate, is the temperature of the component;

[0075] (3) Thermal convection refers to the heat exchange process that occurs when a fluid (such as air or liquid) flows over a solid surface. Thermal convection analysis of a battery pack needs to consider the flow rate, temperature and physical properties of the fluid, as well as the geometry and material properties of the solid surface. Thermal convection is represented by the following formula:

[0076] ;

[0077] in, is the heat of thermal convection, is the surface convection heat transfer coefficient of the component, is the convective heat transfer area of ​​the component surface, is the surface temperature of the convection heat transfer surface of the component, The fluid temperature on the convection heat transfer surface of the component

[0078] (4) Thermal radiation is a method by which an object transfers energy through electromagnetic waves, and it does not require a medium. In a battery pack, thermal radiation may not be the main method of heat transfer, but in a high temperature or closed environment, radiation heat transfer may become important. Thermal radiation is represented by the following formula:

[0079] ;

[0080] in, is the surface emissivity of the component, is the heat radiation surface area of ​​the component, is the surface temperature of the heat radiation component, is the surface temperature of the heat radiated component, For blackness, The heat of thermal radiation.

[0081] Furthermore, in other implementations of this embodiment, before step S101, the method further includes:

[0082] When performing ARC testing on a single cell, obtain the self-heating starting temperature of the single cell , Thermal runaway trigger temperature , Maximum temperature of thermal runaway and thermal runaway gas production temperature In order to accurately obtain the temperature parameters of the single cell to be simulated through testing, the parameters of the single cell tested by ARC and the single cell to be simulated must be kept consistent to improve the simulation accuracy and avoid errors.

[0083] It should be noted that the purpose of ARC testing on single cells is also to obtain the heat generation data, gas production data, etc. of the single cells in the process of triggering thermal runaway, which can be used as standards in the thermal runaway simulation process, thereby simplifying the method and avoiding fitting complex parameters.

[0084] It is understandable that the ARC test needs to be conducted in an adiabatic environment, which is generally achieved through an adiabatic calorimeter. The temperature of the cylinder wall inside the adiabatic calorimeter follows the battery temperature in real time to ensure that there is no heat exchange between the battery and the external environment. After the single cell is triggered to generate heat, the temperature of the single cell is monitored over time and the gas production of the battery after the thermal runaway is triggered is collected.

[0085] It should be noted that during the ARC test, the starting temperature of the self-heating of the single cell must be correctly identified. , Thermal runaway trigger temperature and thermal runaway maximum temperature . This is the point where the temperature of the single cell starts to rise autonomously after heating is stopped during the test. The thermal runaway trigger temperature of the single battery (i.e. The temperature of the single battery rises sharply). Corresponding to the highest temperature reached during thermal runaway, the temperature directly affects the severity and possible consequences of thermal runaway. A typical ARC test temperature data of a single cell is as follows: Figure 2 shown.

[0086] S102, detecting the temperature of the single battery in the battery pack, and determining whether there is a target single battery, wherein the target single battery has a temperature reaching the self-heating starting temperature If not, the process returns to step S101; if so, the process proceeds to step S103.

[0087] It should be noted that this step is to monitor the temperature of all single cells in the battery pack in real time through simulation, and set up a logical judgment mechanism to identify whether the temperature has reached the starting temperature of self-heating. The specific single cell is called the "target single cell". If there is no such battery, the process returns to step S101 to continue monitoring; once found, the process immediately proceeds to the next step.

[0088] S103: Determine the heat value corresponding to the target single cell at the current temperature according to the first setting strategy. , to be loaded into the heat transfer analysis; the first setting strategy is based on functional relationship or interpolation calculation.

[0089] It should be noted that this step can accurately determine the heat generation of the target single cell at the current temperature based on a pre-set first setting strategy (which is a simple functional relationship or an efficient interpolation algorithm) to quantify the energy release during the entire thermal runaway process, providing key data support for subsequent simulation of the thermal runaway process. At the same time, it can simplify the method and avoid fitting and identifying complex electrochemical parameters.

[0090] Further, in other implementations of this embodiment, when the first setting strategy is based on a functional relationship, the step S103 may be refined to include the following contents:

[0091] (1) Obtaining the temperature and heat value of a single battery The functional relationship between ,in, is the heat generated by the target single cell, and T is the current temperature of the target single cell;

[0092] (2) Determine the heat value corresponding to the target single cell at the current temperature according to the functional relationship ;

[0093] (3) The heat generated by the target single cell is loaded into the heat exchange analysis so that the heating amount of each thermal runaway single cell can be loaded during the simulation process in the battery pack. Different heating amounts can be loaded according to the different temperatures of each single cell, which can more realistically reflect the heat source distribution inside the battery pack and accurately predict the battery temperature field.

[0094] It should be noted that when a single cell undergoes thermal runaway, the exothermic reaction of the single cell during thermal runaway follows the Arrhenius equation, and the temperature and heat generation of the single cell are related to each other. The functional relationship between them is expressed by the following formula: ;

[0095] in, is the heat generation power of the single cell, is the volume of the single cell, is the degree of thermal runaway reaction;

[0096] ;

[0097] in, , , , , is the model constant, is the temperature of the single cell, is the degree of thermal runaway reaction, is the universal gas constant.

[0098] According to the above principle, the heat generated by a single battery It can be expressed as being only related to temperature, but since it involves the aforementioned reaction parameters, it is difficult to identify and ensure accuracy. Therefore, in this application, the heating power of a single cell is determined by ARC testing. To directly determine the heat generated by a single cell , avoid complicated fitting process, simplify the method and improve the accuracy.

[0099] Specifically, the heating power of a single battery is obtained by the following formula: :

[0100] ;

[0101] in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC;

[0102] After obtaining the heating power corresponding to each temperature, multiply it by each simulation time step to determine the heating power at that temperature, that is, The temperature and heat generation of the single battery are generated by integrating the simulation time step The functional relationship between For example, please refer to Figure 3 shown.

[0103] It should be noted that the temperature and heat generation of the single cell carefully constructed above The functional relationship between them can greatly simplify the analysis process and avoid the tedious steps of fitting a large number of complex parameters for simulation in traditional methods. This method not only improves the accuracy of the analysis, but also significantly improves work efficiency.

[0104] By determining the heat generated by the target single cell at the current temperature based on the precise functional relationship, this method effectively avoids the challenges and difficulties faced in identifying various complex reaction parameters when a thermal runaway event occurs. By directly using the established functional model for calculation, key information can be quickly and accurately obtained, thereby greatly simplifying the thermal runaway analysis process and improving the accuracy and efficiency of the analysis.

[0105] Further, in other implementations of this embodiment, when the first setting strategy is based on interpolation calculation, the step S103 may be refined to include the following contents:

[0106] (1) Obtaining known data points of a single cell, including the temperature of the single cell and the corresponding calorific value ;

[0107] (2) Based on the known data points, the calorific value corresponding to the target single cell at the current temperature is calculated by interpolation method. .

[0108] Known data points of a single cell are used to determine the heating power of the single cell through ARC testing Get. The method of determining the calorific value by the heating power is mentioned above and will not be repeated here. The calorific value corresponding to different temperatures can be determined by the heating power at different temperatures. Furthermore, through multiple known data points, linear interpolation, polynomial interpolation and the like can be used to calculate the unknown data points, that is, the calorific value at an unknown temperature is calculated by the calorific value at a known temperature. The calorific value of a single cell during thermal runaway can be characterized and calculated by interpolating the corresponding temperature, thus avoiding the problem of difficulty in identifying various reaction parameters when simulating thermal runaway using existing technologies.

[0109] It should be noted that each single cell has a corresponding temperature at each simulation time step. Therefore, the corresponding calorific value is determined according to the temperature of the single cell at each simulation time step and loaded into the heat exchange analysis to ensure the simulation accuracy.

[0110] Furthermore, in order to improve the simulation accuracy, thermal runaway gas generation is also considered in this application, specifically, the following steps are included:

[0111] S104: Determine whether the current temperature of the target single cell reaches the thermal runaway gas generation temperature. ; If not, return to execute S101, if so, execute S105.

[0112] It should be noted that this step is to further determine whether the target single cell has reached the temperature threshold of thermal runaway gas production, which is an important indicator for evaluating whether the battery thermal runaway has entered a serious stage. If it has not been reached, the cycle is repeated; once it is reached, the next step is performed. Figure 2 It can be seen that thermal runaway of a single battery is a process of temperature change. During the thermal runaway process, it will undergo multiple chemical reaction processes. The self-heating starting temperature refers to the temperature at which the chemical reaction inside the battery begins to proceed spontaneously and generate heat, while the gas generation temperature refers to the temperature at which the chemical reaction inside the battery is more intense at a higher temperature and a large amount of gas is generated. > . By setting two different temperatures to simulate the thermal runaway process of a single cell, while loading the heat generated, the temperature caused by the thermal runaway gas is loaded, which can simulate the thermal runaway process more realistically.

[0113] S105: Determine the gas mass flow rate corresponding to the target single cell at the current temperature according to the second setting strategy. , to be loaded into the heat exchange analysis; the second setting strategy is based on a functional relationship or interpolation calculation. Then S106 is executed.

[0114] It should be noted that according to the second strategy (also based on an accurate functional relationship or interpolation method), the gas mass flow rate of the target single cell in the current thermal runaway stage is accurately calculated. This data is crucial for evaluating the internal pressure changes, gas emissions, temperature of the battery pack and its impact on the surrounding environment.

[0115] Further, in other implementations of this embodiment, when the second setting strategy is based on a functional relationship, the step S105 may be refined to include the following contents:

[0116] (1) Obtaining the temperature and gas mass flow rate of the single cell The functional relationship between the temperature of the single cell and the gas mass flow rate The functional relationship between them is expressed by the following formula:

[0117] ,in, is the gas mass flow rate of the target single cell, T is the current temperature of the target single cell, and the gas mass flow rate Temperature of single cell The relationship can be processed into Figure 3 The form shown is substituted into the Table for calculation;

[0118] (2) According to the functional relationship, determine the gas mass flow rate corresponding to the target single cell at the current temperature ;

[0119] (3) The gas mass flow rate Load it into the heat exchange analysis. Specifically, set the gas mass flow rate at the explosion-proof valve position of the target single cell and temperature.

[0120] In this embodiment, the temperature of the single cell and the gas mass flow rate The functional relationship between them is obtained through ARC test according to the following formula:

[0121] ;

[0122] in, is the weighing mass of the gas, For ARC test time, each Corresponding to the temperature of one of the target single cells.

[0123] Specifically, for each temperature T, the corresponding gas mass flow rate is calculated by integration at the simulation time step, so that the temperature and gas mass flow rate of the single cell can be determined. Functional relationship between It should be noted that in the prior art, gas simulation is performed by calculating the explosion-proof valve outlet velocity, outlet cross-sectional area and other methods. Since the gas flow velocity at the explosion-proof valve outlet is not uniform, the flow velocity at the center of the outlet cross-sectional area is the largest, and the velocity decreases and approaches zero as it approaches the edge of the outlet cross-sectional area, and the outlet flow velocity cannot be accurately obtained.

[0124] The temperature and gas mass flow rate of the single cell are carefully constructed as described above. The functional relationship between them can greatly simplify the analysis process and avoid the tedious steps of fitting a large number of complex parameters for simulation in traditional methods. This method not only improves the accuracy of the analysis, but also significantly improves work efficiency.

[0125] The gas mass flow rate corresponding to the target single cell at the current temperature is determined based on the precise functional relationship. This method effectively avoids the challenges and difficulties faced in identifying various complex reaction parameters when thermal runaway events occur. By directly using the established function model for calculation, key information can be obtained quickly and accurately, which greatly simplifies the thermal runaway analysis process and improves the accuracy and efficiency of the analysis.

[0126] Further, in other implementations of this embodiment, when the second setting strategy is based on interpolation calculation, the step S105 can be refined to include the following contents:

[0127] (1) Obtaining known data points of a single cell, wherein the known data points include the temperature of the single cell and the corresponding gas mass flow rate ;

[0128] (2) Based on the known data points, the gas mass flow rate corresponding to the target single cell at the current temperature is calculated by interpolation method. .

[0129] In this embodiment, the known data points of the single battery are obtained through ARC testing according to the following formula:

[0130] ;

[0131] in, is the weighing mass of the gas, For ARC test time, each Corresponding to the temperature of one of the target single cells.

[0132] It should be noted that the gas mass flow rate of a single cell can be seen from the above formula can be described as being only related to time, since each test time There is a corresponding target single cell temperature T, so the gas mass flow rate of the single cell can be established The functional relationship with temperature, or the gas mass flow rate when the single cell thermal runaway occurs can be characterized and calculated by interpolating the corresponding test time. This avoids the difficulty in identifying the various reaction parameters when using existing technologies for thermal runaway simulation. Gas mass flow rate of a single cell The temperature of the single cell The relationship can be processed into Figure 4 The form shown is substituted into the Table for calculation.

[0133] S106, checking whether the set cut-off condition is met; if not, returning to execute the step S101, and if so, executing step S107.

[0134] It should be noted that this step is to detect whether the simulation process has reached the point where the preset simulation end condition is met. If not, the cycle monitoring continues; once it is met, the final step is entered.

[0135] S107, simulation ends.

[0136] It should be noted that this step marks the end of the thermal runaway simulation of the entire battery pack. At this time, all key data, charts and analysis results will be output, providing a scientific basis for the design and optimization of the battery pack, and also laying a data foundation for subsequent safety performance evaluation and improvement work.

[0137] Further, in other implementations of this embodiment, step S106 specifically includes:

[0138] The total calorific value of the target single cell at different temperatures is calculated and determined, and compared with the preset calorific value. If the total calorific value of the target single cell reaches the preset calorific value, the cutoff condition is met, wherein the preset calorific value is obtained by the total calorific value of the ARC test cell.

[0139] If the detection does not meet the cut-off condition, the process returns to step S101 ; if the cut-off condition is met, the process proceeds to step S107 .

[0140] It should be noted that this step continuously monitors the thermal runaway process of the target single cell to confirm whether it has completed all stages of thermal runaway. If not, the cycle monitoring continues; once it is confirmed to be completed, the cut-off stage is entered to output the analysis results.

[0141] Furthermore, in this embodiment, the total heat value of the target single cell is obtained by adding the heat value of each time step in the total duration in the simulation, and the preset heat value is obtained by integrating the heat value in the same total duration in the ARC test. It is obtained by the following formula:

[0142] ;

[0143] in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

[0144] If the total heat value of the target single battery under the total time is equal to the preset heat value under the total time If the temperature is the same, the target single cell heating power is changed to 0, and the simulation is terminated. Compared with the prior art, the stop time is used as the cutoff condition, the temperature change is ignored, and the actual thermal runaway state of the battery cannot be accurately reflected. The battery temperature near the thermal runaway triggering single cell is used as the cutoff condition. Since the temperature change of the nearby battery lags behind the occurrence of thermal runaway, there is a reaction hysteresis and it is impossible to capture the rapid change of thermal runaway. In this application, the total heat output of the target single cell is used as the cutoff condition, which can directly reflect the essence of thermal runaway, timely capture the early signs of thermal runaway, and improve the accuracy and sensitivity of early warning. The total heat output is calculated by the above formula, which changes with the simulation time and the temperature of the single cell, and can adapt to different simulation conditions, which helps to optimize the design of the thermal management system and improve the overall applicability.

[0145] The present invention provides a battery pack thermal runaway simulation method, which performs heat exchange analysis on components in the battery pack, detects and determines the target single cell that generates self-heat, and then establishes the relationship between the calorific value and gas mass flow rate of the target single cell and the temperature of the target single cell. This can achieve fast and accurate simulation of the thermal runaway of the battery pack, avoiding the problem of difficulty in solving equation parameters in the prior art, thereby facilitating shortening the time of thermal runaway simulation, reducing experimental costs in the design and development stage, and helping to promote the development of new energy vehicles and energy storage technologies in a safer and more reliable direction.

[0146] Embodiment 2

[0147] Figure 5 A schematic diagram of the structure of a battery pack thermal runaway simulation system provided in Embodiment 2 of the present invention. Figure 5 A block diagram of an exemplary computer device 12 suitable for use in implementing embodiments of the present invention is shown. Figure 5 The computer device 12 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0148] like Figure 5As shown, the computer device 12 is in the form of a general-purpose computing device. The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0149] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures. By way of example, these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0150] The computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0151] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 5 not shown, usually called a "hard drive"). Although Figure 5 Not shown in the figure, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, a DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present invention.

[0152] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described herein.

[0153] The computer device 12 may also communicate with one or more external devices 14 (e.g., keyboards, pointing devices, displays 24, etc.), one or more devices that enable a user to interact with the computer device 12, and / or any device that enables the computer device 12 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Such communication may be performed via an input / output (I / O) interface 22. In addition, the computer device 12 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 20. As shown, the network adapter 20 communicates with the other modules of the computer device 12 via a bus 18. It should be understood that although Figure 5 Not shown, other hardware and / or software modules may be used in conjunction with computer device 12, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0154] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing the battery pack thermal runaway simulation method provided in the embodiment of the present invention.

[0155] Embodiment 3

[0156] Embodiment 3 of the present invention provides a computer-readable storage medium having computer-executable instructions stored thereon. When the instructions are executed by a processor, the battery pack thermal runaway simulation method provided in all the embodiments of the present application is implemented.

[0157] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, device, or device.

[0158] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0159] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0160] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0161] Finally, it should be noted that although the above embodiments have been described in the specification and drawings of this application, this does not limit the scope of patent protection of this application. All technical solutions generated by replacing or modifying equivalent structures or equivalent processes based on the essential concept of this application using the contents recorded in the specification and drawings of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, are included in the scope of patent protection of this application.

Claims

1. A battery pack thermal runaway simulation method, characterized in that: include: S101, performing heat exchange analysis on components in the battery pack; S102, detecting the temperature of the single battery in the battery pack, and determining whether there is a target single battery, wherein the target single battery has a temperature reaching the self-heating starting temperature Single battery; If not, then return to execute S101, if so, then execute S103; S103: Determine the heat value corresponding to the target single cell at the current temperature according to the first setting strategy. , to be loaded into the heat exchange analysis; the first setting strategy is based on a functional relationship or interpolation calculation; S104: Determine whether the current temperature of the target single cell reaches the thermal runaway gas generation temperature. ; If not, return to execute S101, if yes, execute S105; S105: Determine the gas mass flow rate corresponding to the target single cell at the current temperature according to the second setting strategy. , to be loaded into the heat exchange analysis; the second setting strategy is based on a functional relationship or interpolation calculation; then S106 is executed; S106, checking whether the set cutoff condition is met; if not, returning to execute S101, if so, executing S107; S107, simulation ends.

2. The battery pack thermal runaway simulation method according to claim 1, characterized in that: Before S101, the method further includes: When performing ARC testing on a single cell, obtain the self-heating starting temperature of the single cell and thermal runaway gas production temperature .

3. The battery pack thermal runaway simulation method according to claim 1, characterized in that: The S106 specifically includes: The total calorific value of the target single cell at different temperatures is calculated and determined, and compared with the preset calorific value. If the total calorific value of the target single cell reaches the preset calorific value, the cutoff condition is met, wherein the preset calorific value is obtained by the total calorific value of the single cell through an ARC test.

4. The battery pack thermal runaway simulation method according to claim 1, characterized in that: When the first setting strategy is based on a functional relationship, S103 specifically includes: Get the temperature and heat of a single battery The functional relationship between the temperature and heat generation of the single cell The functional relationship between them is expressed by the following formula: ， in, is the heat generated by the target single cell, and T is the current temperature of the target single cell; The temperature and heat generation of the single cell The functional relationship between them is determined by the ARC test according to the following formula to determine the heating power of the single battery. get: ； in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

5. The battery pack thermal runaway simulation method according to claim 1, characterized in that: When the first setting strategy is based on interpolation calculation, S103 specifically includes: Obtain known data points of the single cell, including the temperature of the single cell and the corresponding calorific value ; Based on the known data points, the calorific value corresponding to the target single battery at the current temperature is calculated by interpolation method. ; The known data points of the single cell are tested by ARC to determine the heating power of the single cell according to the following formula: get: ； in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

6. The battery pack thermal runaway simulation method according to claim 1, characterized in that: When the second setting strategy is based on a functional relationship, S105 specifically includes: Obtain the temperature and gas mass flow rate of the single cell The functional relationship between the temperature of the single cell and the gas mass flow rate The functional relationship between them is expressed by the following formula: ， in, is the gas mass flow rate of the target single cell, T is the current temperature of the target single cell; Wherein, the temperature of the single cell and the gas mass flow rate The functional relationship between them is obtained through ARC test according to the following formula: ； in, is the weighing mass of the gas, Testing time for ARC.

7. The battery pack thermal runaway simulation method according to claim 1, characterized in that: When the second setting strategy is based on interpolation calculation, S105 specifically includes: Acquire known data points of the single cell, the known data points including the temperature of the single cell and the corresponding gas mass flow rate ; Based on the known data points, the gas mass flow rate corresponding to the target single cell at the current temperature is calculated by interpolation method. ; The known data points of the single cell are calculated by the ARC test according to the following formula: ； in, is the weighing mass of the gas, For ARC test time, each Corresponding to the temperature of one of the target single cells.

8. The battery pack thermal runaway simulation method according to claim 3, characterized in that: The preset heating value is obtained by the following formula: ； in, is the specific heat capacity of the single cell, is the mass of the single battery, is the temperature of the single cell during the ARC test, Testing time for ARC.

9. A battery pack thermal runaway simulation system, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the battery pack thermal runaway simulation method according to any one of claims 1 to 8 is implemented.

10. A storage medium containing computer executable instructions, characterized in that: The computer executable instructions are executed by a computer processor to implement the battery pack thermal runaway simulation method as described in any one of claims 1 to 8.

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