低压环境下新型清洁灭火剂抑灭锂离子电池火试验

Experimental test for fire suppression of the lithium-ion battery with a novelty clean fire extinguishing agent at the low pressure

为研究可替代哈龙的新型气体灭火剂2-溴-3,3,3三氟丙烯(2-BTP)抑制和扑灭航空货运锂离子电池火的有效性,基于动压变温试验舱和灭火系统开展试验。在80kPa、60kPa和40kPa低压环境下对100%电量的21700锂离子电池用加热棒进行加热并引发其热失控,同时启动灭火系统释放灭火剂。在试验过程中实时采集记录锂离子电池的温度、热失控现象,以及舱内环境空气中CO体积分数的变化。结果表明,2-BTP灭火剂在低压环境下能有效扑灭锂离子电池火且无复燃,减少CO的生成量,同时能够抑制相邻锂离子电池间的热传播,从而阻止连锁热失控。

In this paper,we would like to conduct experiments to test and check the effectiveness of 2-BTP in suppressing and extinguishing the fire caused in the lithium-ion batteries in the civil aircraft transport 2-bromo-3,3,3 trifluoropropene(2-BTP).As is well known,2-BTP is a novelty clean gas extinguishing agent that can be expected to replace Halon agents.In fact,the experimental platform consists of the dynamic-pressure and variable-temperature test cabin in the fire extinguishing system.The testing cabin should be able to change the pressure in the cabin from the ordinary one to 10 k Pa just through pumping for 10 minutes to simulate the environmental pressure when the aircraft is flying up to the high altitude.In the test,the refillable fire extinguisher we have prepared ourselves may enclose 600 m L2-BTP filled with nitrogen to reach 2.5 MPa,in which the batteries are to be arranged vertically one by two.At the same time,the pressure conditions of the experiment should be equipped with 80 k Pa,60 k Pa and 40 k Pa.In the experiment,the first21700 lithium-ion battery has to be heated with a heating rod up to full power of 100%.And,then,the fire extinguishing system has to be started to release its fire extinguishing agent in case the first battery were to be being thermal runaway and exploded.Moreover,we have also analyzed the fire extinguishing performance of 2-BTP from the following 3 perspectives:the experimental phenomena,the cooling effect and the content change of the carbon monoxide in the ambient air of the cabin pre-&-pro the release.Hence,in so doing,the experimental situation and phenomena concerned have to be recorded with a camera device.Besides,a paperless recorder can be used to register the K-type thermocouples whereas the surface temperature can be measured and recorded by the side of every battery.A flue gas analyzer can also help to measure precisely the concentrations of the carbon monoxide with all the data transferred to and processed by the computer.And,last of all,the testing results can indicate that just during a short time period of 10 seconds,it would be possible for 600 m L 2-BTP to get released to extinguish fire effectively with no need for re-ignition.It is also possible to reduce the amount of the carbon monoxide generated so as to inhibit the heat propagation between the adjacent lithium-ion batteries and prevent the chain thermal runaway.