高倍泡沫对LNG池火抑制效能研究

STUDY ON THE INHIBITION EFFICIENCY OF HIGH-EXPANSION FOAM TO LNG POOL FIRE

液化天然气(LNG)储罐和槽车发生泄漏后在低洼处形成液池,LNG快速气化并与空气混合形成爆炸性气云,爆炸性气云和LNG液池均易引发火灾、爆炸事故,酿成灾难性后果,亟需开展LNG泄漏扩散过程、燃烧过程及火灾扑救方面的研究。搭建了大尺度LNG池火测试与火灾扑救实验平台,应用高速摄像、红外热像仪、热电偶树和热流密度计等测试手段开展了LNG泄漏扩散过程、LNG池火燃烧机理及高倍泡沫对LNG池火抑制的实验研究。结果表明:LNG泄漏扩散过程分为快速气化、沿地面蔓延和扩散消散三个阶段。高倍泡沫对LNG池火有较好的抑制作用,能显著降低LNG池火对周边构建筑物的热辐射危害,但高倍泡沫在7.2~7.5 L/m^2·min供给强度下,无法彻底扑救LNG池火,需结合其他方法才能有效地扑救LNG池火。

Liquefied natural gas( LNG) tank and tanker leak occurred after the formation of liquid pool in the lowlying place. LNG gasified quickly and mixed with air to form explosive gas cloud which is easy to cause fire and explosion accidents just like liquid pool LNG and result in disastrous consequences. Therefore,it is urgent to carry out researches on LNG leakage diffusion process,combustion process and firefighting. A large scale LNG pool fire test and fire extinguishing test platform is built. High speed camera,infrared thermal imager,thermocouple tree and heat flux meter are used to carry out the LNG leakage diffusion process,LNG pool fire combustion mechanism and experimental study on the suppression of LNG pool fire by the high temperature foam. The results show that the LNG leakage diffusion process can be divided into three stages:rapid gasification,surface spreading and diffusion dissipation. High-expansion foam has a good inhibitory effect on LNG pool fire,and can significantly reduce the thermal radiation hazard of LNG pool fire to the surrounding buildings. But high-expansion foam can 't completely put out the LNG pool fire with the supply intensity of 7. 2 ~7. 5 L/m^2·min. Such foam needs to be combined with other methods to fight LNG pool fire effectively.