Method and device for detecting performance of flame-retardant fireproof material applied to power battery pack

Abstract

This invention relates to the field of data processing technology, specifically to a method and equipment for testing the performance of flame-retardant and fire-resistant materials used in power battery packs. The method includes: analyzing the changes in gas concentration and temperature of the material under test during a combustion experiment to obtain pyrolysis characteristic information and flame propagation characteristic information; determining a target time to separate the pyrolysis stage and the flame propagation stage based on the pyrolysis characteristic information and the flame propagation characteristic information; analyzing the first cumulative heat generation corresponding to the pyrolysis stage and the second cumulative heat generation corresponding to the flame propagation stage to determine the pyrolysis heat generation contribution index corresponding to the pyrolysis stage and the combustion heat generation contribution index corresponding to the flame propagation stage; and determining the fire resistance performance of the material under test based on the pyrolysis heat generation contribution index, the combustion heat generation contribution index, and the temperature value corresponding to the target time. This invention can improve the accuracy of testing the flame-retardant and fire-resistant properties of power battery pack materials.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and more specifically to a method and equipment for testing the performance of flame-retardant and fire-resistant materials used in power battery packs. Background Technology

[0002] Flame-retardant and fire-resistant materials specifically designed for power battery packs are among the key materials used in electric vehicles (EVs) and other power battery systems to improve battery safety, extend battery life, and enhance performance. With the rapid growth of the electric vehicle market, power battery packs (especially lithium-ion battery packs) may generate heat during operation, potentially leading to thermal runaway or fires, particularly under extreme conditions such as high temperatures or short circuits. Therefore, the development and use of materials with excellent thermal insulation, flame-retardant, and fire-resistant properties are of paramount importance.

[0003] Currently, the flame retardant and fireproof properties of power battery pack materials are generally evaluated by obtaining the heat release rate (HRR) of the material through combustion experiments. However, since it is difficult to accurately distinguish between the pyrolysis stage and the flame propagation stage during the combustion experiment, the HRR test results cannot effectively distinguish the heat contribution of the pyrolysis stage and the flame propagation stage during the combustion process. This will lead to errors in the actual flame retardant and fireproof performance corresponding to the material's heat release rate results.

[0004] In other words, the accuracy of existing technologies in detecting the flame-retardant and fire-resistant properties of power battery pack materials is relatively low. Summary of the Invention

[0005] To address the technical problem of low accuracy in testing the flame-retardant and fire-resistant properties of power battery pack materials in existing technologies, the present invention aims to provide a method and equipment for testing the performance of flame-retardant and fire-resistant materials used in power battery packs. The specific technical solution adopted is as follows: In a first aspect, one embodiment of the present invention provides a method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs, the method comprising: By analyzing the changes in gas concentration and temperature of the material under test during the combustion experiment, pyrolysis characteristic information and flame propagation characteristic information can be obtained. Based on the pyrolysis characteristic information and the flame propagation characteristic information, a target time is determined, wherein the target time is used to separate the pyrolysis stage and the flame propagation stage of the material under test in the combustion experiment; Analyze the first cumulative heat production corresponding to the pyrolysis stage and the second cumulative heat production of the flame propagation stage to determine the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index of the flame propagation stage. The fire resistance of the material under test is determined based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time.

[0006] In one embodiment, the analysis of gas concentration changes and temperature changes corresponding to the test material during the combustion experiment to obtain pyrolysis characteristic information and flame propagation characteristic information includes: In the combustion experiment, the average concentration of combustible gas and the concentration of carbon dioxide detected at each time point are analyzed to obtain multiple pyrolysis significant features. The multiple time points correspond one-to-one with the multiple pyrolysis significant features, and the pyrolysis feature information includes the multiple pyrolysis significant features. At the multiple time points, the oxygen consumption rate and temperature increase detected at each time point are analyzed to obtain multiple significant combustion features. The multiple time points correspond one-to-one with the multiple significant combustion features, and the flame propagation feature information includes the multiple significant combustion features.

[0007] In one embodiment, determining the target time based on the pyrolysis characteristic information and the flame propagation characteristic information includes: At the multiple time points, the differences in significant pyrolysis characteristics between adjacent time points are analyzed to obtain the pyrolysis characteristic change value corresponding to each time point; In the multiple time periods, the differences in significant combustion characteristics between adjacent time periods are analyzed to obtain the combustion characteristic change value corresponding to each time period; Based on the changes in pyrolysis and combustion characteristics at each time point, determine the transition stage probability at each time point. Among the multiple moments, the moment with the highest probability of transitioning to the next phase is determined as the target moment.

[0008] In one embodiment, determining the transition stage probability at each moment based on the pyrolysis characteristic change value and the combustion characteristic change value at each moment includes: Calculate the product of the pyrolysis characteristic change value and the combustion characteristic change value at each time step to obtain the transition stage probability at each time step.

[0009] In one embodiment, the change value of the pyrolysis characteristics at each time moment is the ratio of the pyrolysis salient feature of the previous time moment to the pyrolysis salient feature of the current time moment. The change value of combustion characteristics at each moment is the ratio of the significant combustion characteristics at the next moment to the significant combustion characteristics at that moment.

[0010] In one embodiment, analyzing the first cumulative heat production corresponding to the pyrolysis stage and the second cumulative heat production corresponding to the flame propagation stage, and determining the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage, includes: Based on the aforementioned multiple pyrolysis characteristics, a first sub-heat generation corresponding to the pyrolysis stage is determined from the second cumulative heat generation. Based on the aforementioned multiple significant combustion characteristics, a second sub-heat generation corresponding to the flame propagation stage is determined from the first cumulative heat generation. The actual cumulative heat production corresponding to the pyrolysis stage is determined based on the first cumulative heat production, the first sub-heat production, and the second sub-heat production. The actual cumulative heat generation corresponding to the flame propagation stage is determined based on the second cumulative heat generation, the first sub-heat generation, and the second sub-heat generation. By analyzing the actual cumulative heat production corresponding to the pyrolysis stage and the actual cumulative heat production corresponding to the flame propagation stage, the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage are determined.

[0011] In one embodiment, determining the first sub-heat generation corresponding to the pyrolysis stage from the second cumulative heat generation based on the plurality of pyrolysis significant characteristics includes: Among the plurality of pyrolysis salient features, the pyrolysis salient features located in the pyrolysis stage are integrated to obtain a first pyrolysis integral value, and the pyrolysis salient features located in the flame propagation stage are integrated to obtain a second pyrolysis integral value; The first sub-heat generation is determined based on the first pyrolysis integral value, the second pyrolysis integral value, and the first cumulative heat generation. The step of determining the second sub-heat generation corresponding to the flame propagation stage from the first cumulative heat generation based on the multiple significant combustion characteristics includes: Among the plurality of significant combustion features, the significant combustion features located in the pyrolysis stage are integrated to obtain a first combustion integral value, and the significant combustion features located in the flame propagation stage are integrated to obtain a second combustion integral value; The first sub-heat generation is determined based on the first combustion integral value, the second combustion integral value, and the second cumulative heat generation.

[0012] In one embodiment, determining the actual cumulative heat production corresponding to the pyrolysis stage based on the first cumulative heat production, the first sub-heat production, and the second sub-heat production includes: Calculate the sum of the first cumulative heat generation and the first sub-heat generation to obtain the first intermediate sum; Calculate the difference between the first intermediate sum and the second sub-heat generation to obtain the actual cumulative heat generation corresponding to the pyrolysis stage; The determination of the actual cumulative heat generation corresponding to the flame propagation stage based on the second cumulative heat generation, the first sub-heat generation, and the second sub-heat generation includes: Calculate the sum of the second cumulative heat production and the second sub-heat production to obtain the second intermediate sum; The difference between the second intermediate sum and the first sub-heat generation is calculated to obtain the actual cumulative heat generation corresponding to the flame propagation stage.

[0013] In one embodiment, determining the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time includes: Calculate the ratio of the pyrolysis heat production contribution index to the combustion heat production contribution index to obtain the target ratio; The product of the target ratio and the temperature value corresponding to the target time is calculated to obtain a performance index used to indicate the fire resistance performance of the material under test.

[0014] Secondly, another embodiment of the present invention provides a flame-retardant and fire-resistant material performance testing device for power battery packs, the device comprising: The feature analysis module is used to analyze the gas concentration and temperature changes of the test material in the combustion experiment to obtain pyrolysis feature information and flame propagation feature information. The stage differentiation module is used to determine the target time based on the pyrolysis characteristic information and the flame propagation characteristic information, wherein the target time is used to separate the pyrolysis stage and the flame propagation stage of the material under test in the combustion experiment; The heat generation analysis module is used to analyze the first cumulative heat generation corresponding to the pyrolysis stage and the second cumulative heat generation of the flame propagation stage, and to determine the pyrolysis heat generation contribution index corresponding to the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage. The performance evaluation module is used to determine the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index and the temperature value corresponding to the target time.

[0015] Thirdly, in another embodiment of the present invention, an electronic device is provided, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method described in the first aspect.

[0016] Fourthly, in another embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the method described in the first aspect.

[0017] The present invention has the following beneficial effects: This invention analyzes the changes in gas concentration and temperature of the material under test during a combustion experiment to determine the characteristics of the corresponding pyrolysis stage and flame propagation stage. Based on this, it accurately separates the pyrolysis and flame propagation stages. Furthermore, it analyzes the first cumulative heat generation of the pyrolysis stage and the second cumulative heat generation of the flame propagation stage to determine the pyrolysis heat generation contribution index of the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage, respectively. Combined with the temperature values ​​corresponding to the separation point between the pyrolysis and flame propagation stages, it accurately evaluates the fire resistance performance of the material under test, thereby improving the accuracy of detecting the flame-retardant and fire-resistant properties of power battery pack materials. Attached Figure Description

[0018] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart of a method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs, provided by an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a flame-retardant and fireproof material performance testing device for power battery packs provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0020] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the flame-retardant and fire-resistant material performance testing method and equipment for power battery packs proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] The specific solution of the flame-retardant and fireproof material performance testing method and equipment for power battery packs provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0023] This invention proposes a method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs. Please refer to [link / reference]. Figure 1 The diagram illustrates a schematic flowchart of a method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs, according to an embodiment of the present invention. The method includes the following steps: Step S1: Analyze the changes in gas concentration and temperature of the material under test during the combustion experiment to obtain pyrolysis characteristic information and flame propagation characteristic information.

[0024] In this invention, the material to be tested should be understood as any kind of flame-retardant and fireproof material used to form a power battery pack, such as high-performance polypropylene material.

[0025] In one example, a combustion experiment can be a process in which the test material is placed in a combustion chamber and a cone heater is used as a heat source to continuously heat the test material until the test material is completely burned (or the oxygen in the combustion chamber is completely consumed).

[0026] The combustion environment of the combustion chamber can be configured in accordance with the ISO 5660-1 standard. During the combustion experiment, a thermogravimetric analyzer can be used to record data such as ambient temperature, oxygen consumption rate, and concentrations of various gases (such as combustible gases such as hydrocarbons, methane, and alcohols, as well as non-combustible gases such as carbon dioxide) in real time. At the same time, a calorimeter (such as an oxygen bomb calorimeter or a cone calorimeter) can be used to measure the heat data released in real time during the combustion process (the sampling start and end time is the entire combustion experiment, and the sampling interval can be 0.2 seconds).

[0027] It should be noted that in this invention, the pyrolysis stage is used to represent the process in which the material under test undergoes thermochemical decomposition when heated, generating combustible volatile components (gas), coke (solid residue), and liquid products. In this process, there is usually no open flame generated, the oxygen consumption is relatively small, and the gas and steam are mainly generated through the decomposition process of the material itself.

[0028] The flame propagation stage is used to describe the process in which pyrolysis products (such as combustible gases) on or inside the test material mix with oxygen, undergo a continuous exothermic oxidation reaction (combustion), and spread along the material surface or space. During this process, the heat release and oxygen consumption of the test material increase significantly, and the flame spreads rapidly.

[0029] It should be understood that the pyrolysis stage precedes the flame propagation stage.

[0030] Specifically, the analysis of the gas concentration and temperature changes of the test material during the combustion experiment yields pyrolysis characteristic information and flame propagation characteristic information, including: In the combustion experiment, the average concentration of combustible gas and the concentration of carbon dioxide detected at each time point are analyzed to obtain multiple pyrolysis significant features. The multiple time points correspond one-to-one with the multiple pyrolysis significant features, and the pyrolysis feature information includes the multiple pyrolysis significant features. At the multiple time points, the oxygen consumption rate and temperature increase detected at each time point are analyzed to obtain multiple significant combustion features. The multiple time points correspond one-to-one with the multiple significant combustion features, and the flame propagation feature information includes the multiple significant combustion features.

[0031] As mentioned earlier, during the pyrolysis stage, the material under test usually produces a large amount of combustible gas without producing obvious flame combustion, that is, very little carbon dioxide is produced by combustion. Therefore, the higher the concentration of combustible gas, the higher the probability that the material is in the pyrolysis stage at the corresponding moment. Similarly, the lower the concentration of carbon dioxide, the higher the probability that the material is in the pyrolysis stage at the corresponding moment.

[0032] Based on this, the present invention analyzes the average concentration of combustible gas and the concentration of carbon dioxide to accurately extract the characteristics indicating the pyrolysis stage at each time point.

[0033] In one example, the ratio of the average concentration of combustible gas detected at each time point to the concentration of carbon dioxide can be determined as the pyrolysis significance characteristic at each time point.

[0034] In this example, the pyrolysis salient features corresponding to the i-th time point among multiple time points It can be represented as: in, Let be the average concentration of combustible gas detected at time i. Let be the carbon dioxide concentration detected at time i, where i is a positive integer less than or equal to the total number of times.

[0035] It should be noted that, in this invention, the various combustible gases detected for the test material should be understood as several combustible gases produced by the test material during the pyrolysis stage, so as to avoid the concentration detection of combustible gases unrelated to the test material interfering with the accuracy of the calculation of significant pyrolysis characteristics.

[0036] As mentioned earlier, during the flame propagation stage, the temperature of the material under test will increase significantly and the oxygen consumption will be more intense. Therefore, the faster the oxygen consumption rate, the higher the probability that the material is in the flame propagation stage at the corresponding moment. Similarly, the higher the temperature increase, the higher the probability that the material is in the flame propagation stage at the corresponding moment.

[0037] Based on this, the present invention analyzes the oxygen consumption rate and temperature increase to accurately extract the characteristics indicating the flame propagation stage at each moment.

[0038] Specifically, the oxygen consumption rate is the ratio of the absolute difference between the oxygen concentration detected at the corresponding moment and the oxygen concentration detected at the previous moment to the time difference between adjacent moments.

[0039] The temperature increase is specifically defined as the absolute difference between the temperature value detected at the corresponding moment and the temperature value detected at the previous moment.

[0040] In one example, the product of the oxygen consumption rate detected at each time point and the temperature increase can be determined as the salient combustion feature at each time point.

[0041] In this example, the combustion salient features corresponding to the i-th time point among multiple time points It can be represented as: in, Let be the oxygen consumption rate detected at time i. Let i be the temperature increase detected at time i. Let i be the temperature value detected at time i. The temperature value detected at time i-1.

[0042] In applications, multiple pyrolysis salient features and multiple combustion salient features can be normalized separately (e.g., using the max-min normalization algorithm) before being used in subsequent processes to eliminate differences between numerical units and further improve the accuracy of subsequent processing.

[0043] Step S2: Determine the target time based on the pyrolysis characteristic information and the flame propagation characteristic information.

[0044] The target time is used to separate the pyrolysis stage and the flame propagation stage of the material under test in the combustion experiment.

[0045] Specifically, determining the target time based on the pyrolysis characteristic information and the flame propagation characteristic information includes: At the multiple time points, the differences in significant pyrolysis characteristics between adjacent time points are analyzed to obtain the pyrolysis characteristic change value corresponding to each time point; In the multiple time periods, the differences in significant combustion characteristics between adjacent time periods are analyzed to obtain the combustion characteristic change value corresponding to each time period; Based on the changes in pyrolysis and combustion characteristics at each time point, determine the transition stage probability at each time point. Among the multiple moments, the moment with the highest probability of transitioning to the next phase is determined as the target moment.

[0046] The change value of the pyrolysis characteristics at each time point is the ratio of the pyrolysis saliency of the previous time point to the pyrolysis saliency of the current time point. The change value of combustion characteristics at each moment is the ratio of the significant combustion characteristics at the next moment to the significant combustion characteristics at that moment.

[0047] It should be understood that during the transition between the pyrolysis stage and the flame propagation stage, there will be a sharp decrease in the pyrolysis characteristics and a sharp increase in the combustion characteristics. Based on this, the present invention analyzes the differences in the pyrolysis characteristics and the differences in the combustion characteristics between adjacent moments to comprehensively assess the probability of the transition moment corresponding to each moment, and selects the moment with the highest probability as the target moment for separating the pyrolysis stage and the flame propagation stage, thereby achieving accurate differentiation between the pyrolysis stage and the flame propagation stage.

[0048] In some implementations, determining the transition stage probability at each time step based on the pyrolysis characteristic change value and the combustion characteristic change value at each time step includes: Calculate the product of the pyrolysis characteristic change value and the combustion characteristic change value at each time step to obtain the transition stage probability at each time step.

[0049] For example, the transition probability corresponding to the i-th time among multiple time points It can be represented as: in, This represents the significant pyrolysis characteristics corresponding to the (i-1)th time step. This represents the significant pyrolysis characteristics at time i. This represents the significant combustion feature corresponding to the (i+1)th time step. This represents the significant combustion characteristics corresponding to the i-th time point. This represents the change in pyrolysis characteristics at time i. This represents the change in combustion characteristics at the i-th time point.

[0050] Step S3: Analyze the first cumulative heat generation corresponding to the pyrolysis stage and the second cumulative heat generation of the flame propagation stage to determine the pyrolysis heat generation contribution index corresponding to the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage.

[0051] Wherein, the first cumulative heat generation can be understood as the total calorific value measured by the calorimeter during the pyrolysis stage, and the second cumulative heat generation can be understood as the total calorific value measured by the calorimeter during the entire combustion experiment minus the first cumulative heat generation.

[0052] It should be noted that during the above combustion experiment, flame propagation may have already occurred before the target time, and material pyrolysis may still occur after the target time. Therefore, after accurately distinguishing between the pyrolysis stage and the flame propagation stage by the target time, it is still necessary to analyze the first cumulative heat generation corresponding to the pyrolysis stage and the second cumulative heat generation of the flame propagation stage to accurately evaluate the pyrolysis heat generation contribution index corresponding to the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage.

[0053] Specifically, the analysis of the first cumulative heat production corresponding to the pyrolysis stage and the second cumulative heat production corresponding to the flame propagation stage, and the determination of the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage, includes: Based on the aforementioned multiple pyrolysis characteristics, a first sub-heat generation corresponding to the pyrolysis stage is determined from the second cumulative heat generation. Based on the aforementioned multiple significant combustion characteristics, a second sub-heat generation corresponding to the flame propagation stage is determined from the first cumulative heat generation. The actual cumulative heat production corresponding to the pyrolysis stage is determined based on the first cumulative heat production, the first sub-heat production, and the second sub-heat production. The actual cumulative heat generation corresponding to the flame propagation stage is determined based on the second cumulative heat generation, the first sub-heat generation, and the second sub-heat generation. By analyzing the actual cumulative heat production corresponding to the pyrolysis stage and the actual cumulative heat production corresponding to the flame propagation stage, the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage are determined.

[0054] Since pyrolysis saliency and combustion saliency respectively reflect the material pyrolysis characteristics and flame propagation characteristics at the corresponding time points, by analyzing multiple pyrolysis saliency and combustion saliency, the heat generation (i.e., the second sub-heat generation) in the pyrolysis stage but corresponding to the flame propagation situation and the heat generation (i.e., the first sub-heat generation) in the flame propagation stage but corresponding to the material pyrolysis situation can be evaluated accordingly. Based on this, the actual cumulative heat generation corresponding to the pyrolysis stage and the actual cumulative heat generation corresponding to the flame propagation stage can be accurately defined, thereby achieving an accurate assessment of the heat generation contribution of the pyrolysis stage and the flame propagation stage, making the subsequently determined pyrolysis heat generation contribution index and combustion heat generation contribution index more accurate and reliable.

[0055] Further, determining the first sub-heat generation corresponding to the pyrolysis stage from the second cumulative heat generation based on the multiple pyrolysis significant characteristics includes: Among the plurality of pyrolysis salient features, the pyrolysis salient features located in the pyrolysis stage are integrated to obtain a first pyrolysis integral value, and the pyrolysis salient features located in the flame propagation stage are integrated to obtain a second pyrolysis integral value; The first sub-heat generation is determined based on the first pyrolysis integral value, the second pyrolysis integral value, and the first cumulative heat generation. The step of determining the second sub-heat generation corresponding to the flame propagation stage from the first cumulative heat generation based on the multiple significant combustion characteristics includes: Among the plurality of significant combustion features, the significant combustion features located in the pyrolysis stage are integrated to obtain a first combustion integral value, and the significant combustion features located in the flame propagation stage are integrated to obtain a second combustion integral value; The first sub-heat generation is determined based on the first combustion integral value, the second combustion integral value, and the second cumulative heat generation.

[0056] In the above setup, the cumulative characteristic values ​​of the material pyrolysis process in the pyrolysis stage and the flame propagation stage are calculated by means of integration, and the cumulative characteristic values ​​of the flame propagation process in the pyrolysis stage and the flame propagation stage are calculated. The cumulative characteristic values ​​are used to characterize the heat generation of the corresponding process (such as the material pyrolysis process or the flame propagation process), thereby accurately guiding the calculation of the first sub-heat generation and the second sub-heat generation.

[0057] The step of determining the actual cumulative heat production corresponding to the pyrolysis stage based on the first cumulative heat production, the first sub-heat production, and the second sub-heat production includes: Calculate the sum of the first cumulative heat generation and the first sub-heat generation to obtain the first intermediate sum; Calculate the difference between the first intermediate sum and the second sub-heat generation to obtain the actual cumulative heat generation corresponding to the pyrolysis stage; The determination of the actual cumulative heat generation corresponding to the flame propagation stage based on the second cumulative heat generation, the first sub-heat generation, and the second sub-heat generation includes: Calculate the sum of the second cumulative heat production and the second sub-heat production to obtain the second intermediate sum; The difference between the second intermediate sum and the first sub-heat generation is calculated to obtain the actual cumulative heat generation corresponding to the flame propagation stage.

[0058] The process of analyzing the actual cumulative heat production corresponding to the pyrolysis stage and the actual cumulative heat production corresponding to the flame propagation stage to determine the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage is as follows: The ratio of the actual cumulative heat production to the total heat production corresponding to the pyrolysis stage is calculated to obtain the pyrolysis heat production contribution index corresponding to the pyrolysis stage; and the ratio of the actual cumulative heat production to the total heat production corresponding to the flame propagation stage is calculated to obtain the combustion heat production contribution index corresponding to the pyrolysis stage, wherein the total heat production is the sum of the actual cumulative heat production corresponding to the pyrolysis stage and the actual cumulative heat production corresponding to the flame propagation stage.

[0059] Step S4: Determine the fire resistance of the material to be tested based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time.

[0060] Specifically, determining the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time includes: Calculate the ratio of the pyrolysis heat production contribution index to the combustion heat production contribution index to obtain the target ratio; The product of the target ratio and the temperature value corresponding to the target time is calculated to obtain a performance index used to indicate the fire resistance performance of the material under test.

[0061] In this invention, the higher the ratio of the pyrolysis heat generation contribution index to the combustion heat generation contribution index, the stronger the ability of the test material to delay the generation of flame (i.e., the less heat the test material releases through combustion), which also indicates that the test material has better fire resistance. Similarly, the higher the temperature value corresponding to the target time, the more heat the test material needs to accumulate to generate an open flame, which also indicates that the test material has better fire resistance.

[0062] For example, the performance index of the material under test It can be represented as: in, This represents the pyrolysis heat production contribution index. This represents the combustion heat production contribution index. This represents the temperature value corresponding to the target time.

[0063] In summary, this invention analyzes the changes in gas concentration and temperature of the test material during a combustion experiment to determine the characteristics of the corresponding pyrolysis stage and flame propagation stage. Based on this, it accurately separates the pyrolysis and flame propagation stages. Furthermore, it analyzes the first cumulative heat generation of the pyrolysis stage and the second cumulative heat generation of the flame propagation stage to determine the pyrolysis heat generation contribution index of the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage, respectively. Combined with the temperature values ​​corresponding to the separation point between the pyrolysis and flame propagation stages, it accurately evaluates the fire resistance performance of the test material, thereby improving the accuracy of detecting the flame-retardant and fire-resistant properties of power battery pack materials.

[0064] In applications, in addition to testing the fire resistance of the material under test based on the above measures, long-term stability and aging tests can also be conducted to assess the degree of decay of the fire resistance of the material under test over time, and to make a more accurate fire resistance performance assessment of the material under test accordingly.

[0065] In one example, based on the above measures, combustion experiments can be conducted on multiple samples of the same mass but with progressively increasing placement times to obtain multiple performance indices. The ratio of the maximum value of the multiple performance indices to the variance of the index decrease can be calculated to determine the fire resistance performance evaluation value of the material under test.

[0066] In this example, the variance of the index decrease is: the variance of the differences between multiple performance indices obtained based on multiple performance indices, where the performance index difference is the absolute difference between two different performance indices at adjacent placement times.

[0067] This invention proposes a performance testing device for flame-retardant and fire-resistant materials used in power battery packs. Please refer to [link / reference]. Figure 2 The diagram illustrates a structural schematic of a flame-retardant and fire-resistant material performance testing device 200 for power battery packs, according to an embodiment of the present invention. The device includes: The feature analysis module 201 is used to analyze the gas concentration changes and temperature changes of the test material in the combustion experiment to obtain pyrolysis feature information and flame propagation feature information. The stage differentiation module 202 is used to determine the target time based on the pyrolysis characteristic information and the flame propagation characteristic information, wherein the target time is used to separate the pyrolysis stage and the flame propagation stage of the material under test in the combustion experiment; The heat generation analysis module 203 is used to analyze the first cumulative heat generation corresponding to the pyrolysis stage and the second cumulative heat generation of the flame propagation stage, and to determine the pyrolysis heat generation contribution index corresponding to the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage. The performance evaluation module 204 is used to determine the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index and the temperature value corresponding to the target time.

[0068] It should be noted that the devices provided in the above embodiments are only illustrative examples of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer device can be divided into different functional modules to complete all or part of the functions described above. Furthermore, the flame-retardant and fire-resistant material performance testing device for power battery packs and the flame-retardant and fire-resistant material performance testing method for power battery packs provided in the above embodiments belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0069] This invention also provides an electronic device. Please refer to [link to relevant documentation]. Figure 3 The electronic device may include a processor 301, a memory 302, and a program 3021 stored in the memory 302 and capable of running on the processor 301.

[0070] When program 3021 is executed by processor 301, it can achieve the following: Figure 1 Any steps in the corresponding method embodiments and the achievement of the same beneficial effects will not be repeated here.

[0071] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by hardware related to program instructions, and the program can be stored in a readable medium.

[0072] This invention also provides a readable storage medium storing a computer program, which, when executed by a processor, can perform the above-described functions. Figure 1 Any step in the corresponding method embodiment can achieve the same technical effect, and will not be repeated here to avoid repetition.

[0073] The computer-readable storage medium of this invention can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0074] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0075] The program code contained on the storage medium can be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0076] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or terminal. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0077] This invention also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to achieve the flame-retardant and fireproof material performance testing method for power battery packs provided in the above embodiments.

[0078] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0079] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for detecting the performance of a fire-retardant fireproof material applied to a power battery pack, characterized in that, The method includes: By analyzing the changes in gas concentration and temperature of the material under test during the combustion experiment, pyrolysis characteristic information and flame propagation characteristic information can be obtained. Based on the pyrolysis characteristic information and the flame propagation characteristic information, a target time is determined, wherein the target time is used to separate the pyrolysis stage and the flame propagation stage of the material under test in the combustion experiment; Analyze the first cumulative heat production corresponding to the pyrolysis stage and the second cumulative heat production of the flame propagation stage to determine the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index of the flame propagation stage. The fire resistance of the material under test is determined based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time. The step of determining the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time includes: Calculate the ratio of the pyrolysis heat production contribution index to the combustion heat production contribution index to obtain the target ratio; Calculate the product of the target ratio and the temperature value corresponding to the target time to obtain a performance index used to indicate the fire resistance performance of the material under test.

2. The method for detecting the performance of a fire-retardant and fireproof material applied to a power battery pack according to claim 1, characterized in that, The analysis of the gas concentration and temperature changes of the test material during the combustion experiment yields pyrolysis characteristic information and flame propagation characteristic information, including: In the combustion experiment, the average concentration of combustible gas and the concentration of carbon dioxide detected at each time point are analyzed to obtain multiple pyrolysis significant features. The multiple time points correspond one-to-one with the multiple pyrolysis significant features, and the pyrolysis feature information includes the multiple pyrolysis significant features. At the multiple time points, the oxygen consumption rate and temperature increase detected at each time point are analyzed to obtain multiple significant combustion features. The multiple time points correspond one-to-one with the multiple significant combustion features, and the flame propagation feature information includes the multiple significant combustion features.

3. The method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs according to claim 2, characterized in that, Determining the target time based on the pyrolysis characteristic information and the flame propagation characteristic information includes: At the multiple time points, the differences in significant pyrolysis characteristics between adjacent time points are analyzed to obtain the pyrolysis characteristic change value corresponding to each time point; In the multiple time periods, the differences in significant combustion characteristics between adjacent time periods are analyzed to obtain the combustion characteristic change value corresponding to each time period; Based on the changes in pyrolysis and combustion characteristics at each time point, determine the transition stage probability at each time point. Among the multiple times, the time with the highest probability of transitioning to the next phase is determined as the target time.

4. The method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs according to claim 3, characterized in that, The step of determining the transition stage probability at each moment based on the pyrolysis characteristic change value and the combustion characteristic change value at each moment includes: Calculate the product of the pyrolysis characteristic change value and the combustion characteristic change value at each time step to obtain the transition stage probability at each time step.

5. The method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs according to claim 3, characterized in that, The change value of the pyrolysis characteristics at each time step is the ratio of the significant pyrolysis characteristics at the previous time step to the significant pyrolysis characteristics at the current time step. The change value of combustion characteristics at each moment is the ratio of the significant combustion characteristics at the next moment to the significant combustion characteristics at that moment.

6. The method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs according to claim 2, characterized in that, The analysis of the first cumulative heat production corresponding to the pyrolysis stage and the second cumulative heat production corresponding to the flame propagation stage, and the determination of the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage, includes: Based on the aforementioned multiple pyrolysis characteristics, a first sub-heat generation corresponding to the pyrolysis stage is determined from the second cumulative heat generation. Based on the aforementioned multiple significant combustion characteristics, a second sub-heat generation corresponding to the flame propagation stage is determined from the first cumulative heat generation. The actual cumulative heat production corresponding to the pyrolysis stage is determined based on the first cumulative heat production, the first sub-heat production, and the second sub-heat production. The actual cumulative heat generation corresponding to the flame propagation stage is determined based on the second cumulative heat generation, the first sub-heat generation, and the second sub-heat generation. By analyzing the actual cumulative heat production corresponding to the pyrolysis stage and the actual cumulative heat production corresponding to the flame propagation stage, the pyrolysis heat production contribution index corresponding to the pyrolysis stage and the combustion heat production contribution index corresponding to the flame propagation stage are determined.

7. The method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs according to claim 6, characterized in that, The step of determining the first sub-heat generation corresponding to the pyrolysis stage from the second cumulative heat generation based on the multiple pyrolysis significant characteristics includes: Among the plurality of pyrolysis salient features, the pyrolysis salient features located in the pyrolysis stage are integrated to obtain a first pyrolysis integral value, and the pyrolysis salient features located in the flame propagation stage are integrated to obtain a second pyrolysis integral value; The first sub-heat generation is determined based on the first pyrolysis integral value, the second pyrolysis integral value, and the first cumulative heat generation. The step of determining the second sub-heat generation corresponding to the flame propagation stage from the first cumulative heat generation based on the multiple significant combustion characteristics includes: Among the plurality of significant combustion features, the significant combustion features located in the pyrolysis stage are integrated to obtain a first combustion integral value, and the significant combustion features located in the flame propagation stage are integrated to obtain a second combustion integral value; The first sub-heat generation is determined based on the first combustion integral value, the second combustion integral value, and the second cumulative heat generation.

8. The method for testing the performance of flame-retardant and fire-resistant materials applied to power battery packs according to claim 6, characterized in that, The determination of the actual cumulative heat production corresponding to the pyrolysis stage based on the first cumulative heat production, the first sub-heat production, and the second sub-heat production includes: Calculate the sum of the first cumulative heat generation and the first sub-heat generation to obtain the first intermediate sum; Calculate the difference between the first intermediate sum and the second sub-heat generation to obtain the actual cumulative heat generation corresponding to the pyrolysis stage; The determination of the actual cumulative heat generation corresponding to the flame propagation stage based on the second cumulative heat generation, the first sub-heat generation, and the second sub-heat generation includes: Calculate the sum of the second cumulative heat production and the second sub-heat production to obtain the second intermediate sum; The difference between the second intermediate sum and the first sub-heat generation is calculated to obtain the actual cumulative heat generation corresponding to the flame propagation stage.

9. A performance testing device for flame-retardant and fire-resistant materials used in power battery packs, characterized in that, The device includes: The feature analysis module is used to analyze the gas concentration and temperature changes of the test material in the combustion experiment to obtain pyrolysis feature information and flame propagation feature information. The stage differentiation module is used to determine the target time based on the pyrolysis characteristic information and the flame propagation characteristic information, wherein the target time is used to separate the pyrolysis stage and the flame propagation stage of the material under test in the combustion experiment; The heat generation analysis module is used to analyze the first cumulative heat generation corresponding to the pyrolysis stage and the second cumulative heat generation of the flame propagation stage, and to determine the pyrolysis heat generation contribution index corresponding to the pyrolysis stage and the combustion heat generation contribution index of the flame propagation stage. The performance evaluation module is used to determine the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index and the temperature value corresponding to the target time. The step of determining the fire resistance of the material under test based on the pyrolysis heat contribution index, the combustion heat contribution index, and the temperature value corresponding to the target time includes: Calculate the ratio of the pyrolysis heat production contribution index to the combustion heat production contribution index to obtain the target ratio; Calculate the product of the target ratio and the temperature value corresponding to the target time to obtain a performance index used to indicate the fire resistance performance of the material under test.

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