Research On Fire Prevention And Control Of New Energy Vehicle Battery Based On Hot Aerosol Fire Extinguishing Agent

In this paper,by understanding the risk of thermal runaway of new energy vehicle battery and relevant preventive measures,analyzing the inducement of thermal runaway in new energy vehicle battery with short circuit as the core,the experimental research on the use of hot aerosol fire extinguishing agent to prevent the spread of fire was carried out,and the key technical parameters were numerically simulated,and the best prevention and control scheme was proposed.The simulation of the thermal runaway lumped chemical reaction kinetics of lithium-ion batteries and the combustion experiment analysis of lithium-ion batteries show that the inflection temperature of the simulated simulation is around 312℃,and the inflection temperature of the lithium-ion combustion experiment is near 296℃.Prevention and control of thermal runaway of lithium batteries before 296℃can effectively prevent the battery from burning.Build an experimental platform for vehicle battery packs,and configure hot aerosol fire extinguishing agent equipment to conduct experimental research to prevent the spread of fire.Set up video and temperature monitoring network,distributed in each module.The experimental results show that when the battery is heated to about 602 seconds,the battery begins to emit smoke;when it is heated to about 658 seconds,the battery begins to open fire;to about 669 seconds,the hot aerosol fire extinguishing agent module starts the spray mode to extinguish the battery pack;to 678 In about seconds,the open flame was extinguished.The temperature of each battery measurement point was monitored for 24 hours.The highest temperature recorded at each monitoring point in the experiment was:487.4℃,287.8℃,87.4℃,43.1℃,26.1℃,26.7℃,25.6℃,indicating that the battery in the experiment The group experienced only one burn.The experimental results of battery packs that do not use hot aerosols for prevention and control show that after one of the batteries is fired,the heat diffusion causes other battery packs to continue to fire,indicating that the hot aerosol module is effective.Based on the analysis of internal short circuit caused by mechanical abuse,electrical abuse,and thermal abuse,eight basic events leading to thermal runaway of new energy vehicle batteries were obtained using the accident tree analysis.Through the analysis of structural importance,it is concluded that preventing heat accumulation（X₈）in lithium-ion batteries is one of the most effective ways to prevent spontaneous ignition of lithium-ion batteries.The hot aerosol fire extinguishing agent can prevent the thermal runaway temperature of other lithium batteries from reaching the critical temperature T₀ in the event of a fire in one of the batteries.