Electric vehicle thermal runaway and disaster hazard assessment method, system and test device

Abstract

The present invention relates to the technical field of thermal runaway assessment of electric vehicles, specifically to a method, system and electronic device for assessing thermal runaway and disaster-causing hazards of electric vehicles. The method comprises placing the vehicle under test and the target object in parallel and maintaining a distance below a gas collection hood; the vehicle triggers thermal runaway and collects key indicators on site; performs hazard dimension analysis, including heat flow assessment analysis, smoke hazard assessment analysis, explosion hazard assessment analysis and open fire hazard assessment analysis; performs weighted assessment according to the assessment results of each dimension, and obtains the results of thermal runaway disaster assessment of electric vehicles. The technical solution can comprehensively and accurately assess the hazard of thermal runaway of electric vehicles.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle thermal runaway assessment, and in particular to an electric vehicle thermal runaway and disaster hazard assessment method, system and electronic equipment. Background Art

[0002] At present, some progress has been made in the thermal runaway testing and evaluation of electric vehicle power batteries. However, there are relatively few evaluation studies on the harmful factors such as smoke, harmful gases, high temperature and radiation generated when the electric vehicle has thermal runaway. This not only affects people's comprehensive understanding of the hazards of thermal runaway of electric vehicles, but also restricts the development and application of related fire extinguishing technologies and countermeasures. Summary of the invention

[0003] The purpose of the present invention is to provide a method, system and electronic equipment for evaluating thermal runaway and disaster-causing hazards of electric vehicles. The technical solution can comprehensively and accurately evaluate the hazard of thermal runaway of electric vehicles.

[0004] To achieve the above objectives, in a first aspect, an embodiment of the present disclosure provides an electric vehicle thermal runaway and disaster hazard assessment method, comprising: placing a vehicle under test and a target object in parallel and maintaining a distance between them under a gas collection hood; triggering thermal runaway of the vehicle and collecting key indicators on site; performing hazard dimension analysis, including heat flow assessment analysis, smoke hazard assessment analysis, explosion hazard assessment analysis and open flame hazard assessment analysis; performing weighted calculations based on the analysis of each hazard dimension to obtain an electric vehicle thermal runaway disaster assessment result.

[0005] Beneficial effects of the basic scheme: By placing the tested vehicle and the target object in parallel and at a distance below the gas collection hood, a real thermal runaway scenario can be simulated, thereby accurately assessing the risk of electric vehicles in a thermal runaway state. The assessment process covers multiple key dimensions, including heat flow, smoke, explosion, and open flame, ensuring the comprehensiveness and accuracy of the assessment. In order to have a more comprehensive understanding of the various hazard factors in the thermal runaway process, it provides strong support for subsequent disaster prevention and control. Weighted assessment based on the assessment of each hazard dimension can more scientifically reflect the overall risk level of thermal runaway disasters in electric vehicles. It not only takes into account the relative importance of each hazard dimension, but also adjusts the weight according to the specific situation, so that the assessment results are more in line with the actual situation.

[0006] The results of thermal runaway disaster assessment of electric vehicles can provide important decision-making basis for automakers, policymakers and consumers. Manufacturers can improve vehicle design and safety based on the assessment results; policymakers can formulate more scientific and reasonable safety standards; consumers can choose safer electric vehicles based on the assessment results. By assessing the thermal runaway disaster of electric vehicles, the continuous development and innovation of related technologies can be promoted. For example, by improving the battery management system, improving thermal isolation performance and other measures, the risk of thermal runaway of electric vehicles can be effectively reduced, promoting the sustainable development of the electric vehicle industry.

[0007] As an implementable preferred solution, the vehicle triggers thermal runaway and collects key indicators on site, including the following:

[0008] Monitor the temperature inside and outside the vehicle in real time; collect smoke and mixed gases, and use flow meters, heat flow meters, hydrogen sensors and smoke sensors to collect and record key indicators in real time; use gas composition analyzers to analyze the composition of smoke and mixed gases.

[0009] As an implementable preferred solution, the heat flow evaluation analysis includes the following:

[0010] The formula for calculating the convective heat release rate is as follows:

[0011]

[0012] in, represents the convective heat release rate (kW), V e represents the exhaust velocity (m / s), A represents the exhaust pipe cross-sectional area (m2), T e Indicates the temperature at the location where the exhaust velocity is measured (K), 353.22 / T e represents the air density at the speed measurement position (kg / m3), T0 represents the test environment temperature (K); T represents the thermocouple measurement temperature (K), C p Represents the specific heat capacity of air (kJ / kg-K), A0=0.9950, A1= -5.29933E-5, A2= 3.21022E-7, A3= -1.22004E-10.

[0013] As an implementable preferred solution, smoke hazard assessment and analysis includes the following:

[0014] The smoke concentration sensor is used to monitor the concentration change of the smoke and obtain the concentration assessment result; the thermal hazard assessment result is obtained according to the temperature of the temperature distribution points in the vehicle body and the cab; and the toxicity assessment result is obtained through analysis by the gas composition analyzer.

[0015] As an implementable preferred solution, the explosion hazard assessment analysis includes evaluating the explosion power; determining the time of thermal runaway when the temperature sensor detects a temperature rise rate greater than 1°C / s and lasts for more than 3 seconds, determining the time of occurrence of thermal runaway through gas sensors or observation, and evaluating the combustion and explosion time; and evaluating the time when smoke enters the cab after thermal runaway occurs.

[0016] As a feasible and preferred solution, the explosion power is evaluated, including the following:

[0017] A pressure sensor is set to convert the shock wave pressure signal generated by the thermal runaway explosion of the battery into a charge signal; the shock wave overpressure peak at different distances is obtained through signal processing, and the proportional distance is defined as follows:

[0018]

[0019] Where r is the distance from the test point to the explosion center (m); W is the mass of TNT (kg);

[0020] By comparing the overpressure data of TNT explosion, we can obtain the TNT equivalent of battery explosion.

[0021] As an implementable preferred solution, an open fire hazard assessment analysis is conducted, including the following:

[0022] Evaluate the time from when thermal runaway occurs to when flames are emitted; arrange dimension lines on the test site, and record and determine the distance of flames through video; arrange multiple temperature sensors on the vehicle body to collect data and evaluate changes in vehicle body temperature.

[0023] In a second aspect, the disclosed embodiments further provide an electric vehicle thermal runaway and disaster hazard assessment system, which utilizes the electric vehicle thermal runaway and disaster hazard assessment method described above.

[0024] On the third aspect, the disclosed embodiment also provides an electric vehicle thermal runaway and disaster hazard assessment test device, including a test platform for placing a vehicle under test, the vehicle under test being connected to a temperature monitoring device; a gas collection hood is arranged above the test platform, for collecting smoke and mixed gas generated by thermal runaway of the vehicle under test, the cross-sectional area of ​​the gas collection hood should be at least 50% larger than the projection area of ​​the vehicle on the horizontal ground; the gas collection hood is connected to a pipeline, a fan, a flow meter, a heat flow meter, a hydrogen sensor and a smoke sensor are arranged in the pipeline; and a gas composition analyzer is also included, which is connected to the pipeline through a gas transport pipeline and is used to analyze the composition of smoke and mixed gas.

[0025] As an implementable preferred solution, the pipeline is L-shaped, the fan is arranged at a corner, and the flow meter is arranged between the fan and the gas collection hood. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the test device for evaluating thermal runaway and disaster hazards of electric vehicles;

[0027] Figure 2 It is a logical schematic diagram of the thermal runaway and disaster hazard assessment method for electric vehicles;

[0028] Figure 3 It is a schematic diagram of the positional relationship between the electric vehicle under test and the target object;

[0029] Figure 4 Schematic diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only partial embodiments of the present invention, which are only used to explain the present application, rather than to limit the present application. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be considered isolated, and they can be combined with each other to achieve better technical effects. The same reference numerals appearing in the drawings of the following embodiments represent the same features or components, which can be applied to different embodiments.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "setting" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection (including various mechanical connection forms, such as couplings or gear pairs, etc.), or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present invention should have the common meanings understood by those skilled in the art in the art to which the present invention belongs.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0034] Explanation of the reference numerals: test platform 100, vehicle under test 101, target object 102, temperature monitoring equipment 103, gas collection hood 200, pipeline 300, fan 301, flow meter 302, heat flow meter 303, hydrogen sensor 304, smoke sensor 305, gas composition analyzer 400, gas transport pipeline 401, electronic device 500, processor 501, communication interface 502, memory 503, bus 504.

[0035] Reference Figure 1 , an electric vehicle thermal runaway and disaster hazard assessment test device, comprising a test platform, the test platform is used to place a vehicle 101 to be tested and a target 102 for detecting the impact of thermal runaway, the vehicle 101 to be tested is connected to a temperature monitoring device 103; a gas collection hood 200 is arranged above the test platform, which is used to collect smoke and mixed gas generated by thermal runaway of the vehicle 101 to be tested, and the cross-sectional area of ​​the gas collection hood 200 should be at least 50% larger than the projection area of ​​the vehicle on the horizontal ground to ensure that all generated smoke and mixed gas can be collected in the hood. The gas collection hood 200 is connected to a pipeline, the pipeline is L-shaped, and a fan 301 is arranged at the corner to suck smoke and mixed gas into the pipeline. A flow meter 302 is arranged between the fan 301 and the gas collection hood 200 to more accurately count the flow data of smoke and mixed gas generated by thermal runaway. A heat flow meter 303, a hydrogen sensor 304 and a smoke sensor 305 are also arranged in the pipeline. The smoke and mixed gas are discharged after exhaust treatment after passing through each sensor in the pipeline. It also includes a gas composition analyzer 400, which is connected to the pipeline through a gas transportation pipeline 401. The gas composition analyzer 400 extracts smoke and mixed gas through the gas transportation pipeline 401 and sends them to the gas composition analyzer 400 for detailed analysis.

[0036] Reference Figure 2 , Electric vehicle thermal runaway and disaster hazard assessment method, using electric vehicle thermal runaway and disaster hazard assessment test device, in order to detect the impact of thermal runaway of the tested vehicle on adjacent vehicles, set the following test method:

[0037] Step S100, the vehicle 101 and the target 102 are placed under the gas collection hood 200, referring to Figure 3 The target object 102 is arranged parallel to the vehicle 101 under test and keeps a distance therebetween. In this embodiment, the distance is not less than 20 cm. The temperature information of the target object 102 close to the vehicle 101 under test is monitored, and the ignition conditions of the tires and plastic parts are recorded. The state of the target object is determined by detecting the degree of damage to the tires and the number of damaged plastic parts after the test.

[0038] Step S200: The vehicle triggers thermal runaway and collects key indicators on site, including:

[0039] Step S201 , monitor the temperature inside and outside the vehicle in real time through the temperature monitoring device 103 .

[0040] In step S202, the generated smoke and mixed gas are collected through the gas collection hood 200. The pipeline 300 is provided with a flow meter 302, a heat flow meter 303, a hydrogen sensor 304 and a smoke sensor 305, etc., to collect and record key indicators of the smoke and mixed gas in real time. The smoke and mixed gas in the pipeline 300 are harmlessly treated and finally discharged to the outside.

[0041] Step S203, extracting smoke and mixed gas through the gas transport pipeline 401 into the gas composition analyzer 400 for detailed analysis. The gas composition analyzer 400 includes a Fourier infrared or gas chromatograph.

[0042] Step S300, perform heat flow assessment (A) analysis, and calculate the convective heat release rate using the following formula:

[0043]

[0044] in, represents the convective heat release rate (kW), V e represents the exhaust velocity (m / s), A represents the exhaust pipe cross-sectional area (m2), T e Indicates the temperature at the location where the exhaust velocity is measured (K), 353.22 / T e represents the air density at the speed measurement position (kg / m3), T0 represents the test environment temperature (K); T represents the thermocouple measurement temperature (K), C p It represents the specific heat capacity of air (kJ / kg-K). A0, A1, A2 and A3 are formula constants. The specific values ​​are A0=0.9950, A1= -5.29933E-5, A2= 3.21022E-7 and A3= -1.22004E-10.

[0045] Step S400, performing smoke hazard assessment (B) analysis, including concentration assessment, thermal hazard and toxicity assessment, specifically including:

[0046] Step S401: call up a smoke concentration sensor to monitor smoke concentration changes and obtain a concentration evaluation result.

[0047] Step S402, obtaining a thermal hazard assessment result according to the temperatures of the temperature distribution points in the vehicle body and the cab.

[0048] Step S403: Obtain toxicity assessment results through analysis by the gas component analyzer 400.

[0049] Step S500, performing explosion hazard assessment (C) analysis, specifically including:

[0050] Step S501, evaluating the explosion power. The degree of harm caused by the thermal runaway explosion of the battery to humans is measured by TNT equivalent, which is equivalent to the power caused by the explosion of TNT of the corresponding mass unit when the battery explodes, specifically including:

[0051] Step S501-1, pressure sensors are installed in the passenger compartment, tire accessories and battery pack to convert the shock wave pressure signal generated by the thermal runaway explosion of the battery into a charge signal.

[0052] Step S501-2, obtain the shock wave overpressure peak values ​​at different distances through signal processing, and define the proportional distance, the formula is as follows:

[0053]

[0054] Where r is the distance from the test point to the explosion center (m); W is the mass of TNT (kg).

[0055] Referring to Table 1, the overpressure data of TNT explosion is compared to obtain the TNT equivalent of battery explosion.

[0056] Table 1

[0057]

[0058] Step S502, evaluate the time from thermal runaway to explosion. When the temperature sensor detects that the temperature rise rate is greater than 1°C / s and lasts for more than 3s, thermal runaway occurs. The occurrence time of the thermal runaway phenomenon is determined by gas sensors or observation, and the explosion time is the time from the occurrence of thermal runaway to the occurrence of the thermal runaway phenomenon, and the time when the explosion conditions are met, and the evaluation result of the time from thermal runaway to explosion is obtained.

[0059] Step S503, evaluating the time when smoke enters the cab, determining the time when thermal runaway occurs based on the data of the temperature sensor, and taking the time when the gas sensor in the cab detects the gas as the time when smoke or mixed gas is detected entering the cab.

[0060] Step S600, performing open fire hazard assessment (D) analysis, specifically including:

[0061] Step S601, evaluate the time from thermal runaway to open flame, and evaluate the time from the occurrence of thermal runaway phenomenon (abnormal chassis noise, smoke emission or rapid temperature increase) to the emission of open flame.

[0062] Step S602, evaluating the open flame spray distance, arranging dimension lines on the test site, and recording and judging the open flame spray distance through video.

[0063] Step S603, evaluating the temperature change of the vehicle body, arranging multiple temperature sensors on the vehicle body, and performing temperature monitoring through the collected data.

[0064] Step S700, weighted calculation is performed according to the analysis of each hazard dimension to obtain the electric vehicle thermal runaway disaster assessment result Z, the formula is as follows:

[0065]

[0066] in, represents the heat flow evaluation result, Heat flow evaluation result weight coefficient; represents the heat flow evaluation result, Weight coefficient of heat flow evaluation results; represents the heat flow evaluation result, Heat flow evaluation result weight coefficient; represents the heat flow evaluation result, Weight coefficient of heat flow evaluation results.

[0067] The disclosed embodiment also provides an electric vehicle thermal runaway and disaster hazard assessment system, which utilizes all steps of the electric vehicle thermal runaway and disaster hazard assessment method in the above embodiment.

[0068] The present disclosure also provides a storage medium in which a computer program is stored. When the computer program is executed by a processor, all steps of the method for assessing thermal runaway and disaster hazard of an electric vehicle in the above-mentioned embodiment can be implemented.

[0069] Those skilled in the art can understand that all or part of the processes in the method for evaluating thermal runaway and disaster-causing hazards of electric vehicles can be implemented by instructing related hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of various embodiments of the method for evaluating thermal runaway and disaster-causing hazards of electric vehicles. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0070] The embodiment of the present application also provides an electronic device for evaluating thermal runaway and disaster hazards of electric vehicles. The electronic device is equipped with a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the method for evaluating thermal runaway and disaster hazards of electric vehicles in any of the above embodiments are implemented. In the embodiment of the present application, the electronic device can be used to handle tests and evaluations related to thermal runaway of electric vehicles. The main operating mode is to use the processor as the control center of the computer system, which can be the processor of a physical machine or the processor of a virtual machine, and to implement different functions by compiling different computer programs.

[0071] Reference Figure 4 , the electronic device 500 includes: at least one processor 501, at least one communication interface 502, at least one memory 503 and at least one bus 504. Among them, the bus 504 is used to realize the connection and communication between these components, the communication interface 502 is used to communicate signaling or data with other node devices, and the memory 503 stores machine-readable instructions executable by the processor 501. When the electronic device 500 is running, the processor 501 communicates with the memory 503 through the bus 504, and when the machine-readable instructions are called by the processor 501, the steps of the electric vehicle thermal runaway and disaster hazard assessment method in any of the above embodiments are executed.

[0072] The above contents are only embodiments of the present invention. The common sense such as the known specific structures and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field to which the invention belongs before the application date or the priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for the ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.

Claims

1. A method for assessing thermal runaway and disaster hazards of electric vehicles, characterized by: include: Place the vehicle to be tested and the target object under the gas collection hood in parallel and keep a distance between them; The vehicle triggers thermal runaway and collects key indicators on site; conducts hazard dimension analysis, including heat flow assessment analysis, smoke hazard assessment analysis, explosion hazard assessment analysis, and open fire hazard assessment analysis; Thermal flow assessment analysis, including the following: The formula for calculating the convective heat release rate is as follows: in, represents the convective heat release rate (kW), V e represents the exhaust velocity (m / s), A represents the exhaust pipe cross-sectional area (m2), T e Indicates the temperature at the location where the exhaust velocity is measured (K), 353.22 / T e represents the air density at the speed measurement position (kg / m3), T0 represents the test environment temperature (K); T represents the thermocouple measurement temperature (K), C p Indicates the specific heat capacity of air (kJ / kg-K), A0=0.9950, A1= -5.29933E-5, A2= 3.21022E-7, A3= -1.22004E-10; Smoke hazard assessment and analysis, including the following: The smoke concentration sensor is used to monitor the concentration change of the smoke and obtain the concentration evaluation result; the thermal hazard evaluation result is obtained according to the temperature of the temperature distribution points in the vehicle body and the cab; the toxicity evaluation result is obtained through the analysis of the gas composition analyzer; Explosion hazard assessment and analysis, including assessment of explosion power; when the temperature sensor detects a temperature rise rate greater than 1°C / s and lasts for more than 3s, it is determined that thermal runaway has occurred; the occurrence time of thermal runaway is determined by gas sensors or observation, and the combustion and explosion time is assessed; the time when smoke enters the cab after thermal runaway occurs is assessed; Fire hazard assessment analysis, including the following: Evaluate the time from when the flames are ejected due to thermal runaway; arrange dimension lines on the test site, and record and judge the distance of the flames ejected through video; arrange multiple temperature sensors on the vehicle body, collect data and evaluate the temperature changes of the vehicle body; A weighted calculation is performed based on the analysis of each hazard dimension to obtain the electric vehicle thermal runaway disaster assessment result.

2. The electric vehicle thermal runaway and disaster hazard assessment method according to claim 1, characterized in that: The vehicle triggers thermal runaway and collects key indicators on site, including the following: Real-time monitoring of vehicle internal and external temperatures; Collect smoke and mixed gases, and collect and record key indicators in real time through flow meters, heat flow meters, hydrogen sensors and smoke sensors; Use a gas composition analyzer to analyze the composition of smoke and mixed gases.

3. The electric vehicle thermal runaway and disaster hazard assessment method according to claim 1, characterized in that: Assess the power of the explosion, including the following: A pressure sensor is set to convert the shock wave pressure signal generated by the thermal runaway explosion of the battery into a charge signal; the shock wave overpressure peak at different distances is obtained through signal processing, and the proportional distance is defined as follows: Where r is the distance from the test point to the explosion center (m); W is the mass of TNT (kg); By comparing the overpressure data of TNT explosion, we can obtain the TNT equivalent of battery explosion.

4. An electric vehicle thermal runaway and disaster hazard assessment system, characterized in that: The electric vehicle thermal runaway and disaster hazard assessment method as described in any one of claims 1 to 3 is used.

5. An electric vehicle thermal runaway and disaster hazard assessment test device, characterized in that: The electric vehicle thermal runaway and disaster hazard assessment method as described in any one of claims 1 to 3 is used; It includes a test platform for placing the vehicle under test, which is connected to a temperature monitoring device; a gas collection hood is arranged above the test platform to collect smoke and mixed gas generated by thermal runaway of the vehicle under test, and the cross-sectional area of ​​the gas collection hood should be at least 50% larger than the projection area of ​​the vehicle on the horizontal ground; the gas collection hood is connected to a pipeline, in which a fan, a flow meter, a heat flow meter, a hydrogen sensor and a smoke sensor are arranged; it also includes a gas composition analyzer, which is connected to the pipeline through a gas transport pipeline and is used to analyze the composition of smoke and mixed gas.

6. The electric vehicle thermal runaway and disaster hazard assessment test device according to claim 5, characterized in that: The pipeline is L-shaped, the fan is arranged at a corner, and the flow meter is arranged between the fan and the gas collection cover.

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