摘要
通过试验测量燃烧区温度的变化过程,研究了超细微粒灭火剂在单室火灾模型下与4种不同类型火焰的相互作用、灭火时间和效果。结果表明,超细微粒灭火剂具有较好的全淹没灭火能力。当1 000g超细微粒灭火剂施放后,位于微粒灭火剂流动路径上的无遮挡火焰(中央火和角落火)能够被迅速扑灭,灭火时间分别为3.9 s和7.2 s;对于火源功率较小的顶棚火,由于火羽流及热泳力的作用,微粒灭火剂能迅速扩散到顶棚,从而能在短时间内将其扑灭,灭火时间约6.3 s;对于遮挡火,其灭火时间较长,约14.3 s。微粒灭火剂浓度对灭火时间有较大影响。当微粒灭火剂的喷射质量为500 g时,虽然中央火、角落火和遮挡火均能被扑灭,但灭火时间都较喷射1 000 g灭火剂时有较长的延长,灭火时间分别为8.1 s,13.9 s和22.2 s。对于需要灭火剂微粒扩散较远距离后灭火的顶棚火,虽然灭火剂在热羽流和热泳力作用下能扩散到顶棚,但因浓度太低,同时由于其他3处火焰熄灭后,灭火室内的氧气消耗速率降低,从而使顶棚火得到足够的氧气,燃烧反应进一步加强,温度反而逐渐升高,不足以将其熄灭。
Interactions of superfine fire extinguishing powder（SFFEP）,which was mainly composed of NH4H2PO3 dealt with silicon oil,with four different single-room fires as well as the fire extinguishing time and fire extinguishing effect were experimentally studied through measuring the temperature of combustion area.Center fire and comer fire have higher flame power while ceiling fire and shelter fire have lower flame power.Experimental results show that SFFEP could be used in total flooding fire extinguishing.When 1 000 g SFFEP was discharged,center fire and corner fire which were located on powder＇ flowing path could be quickly extinguished,and fire extinguishing time was about 3.9 s and 7.2 s,respectively.On the other hand,ceiling fire could be extinguished in a short time,i.e.about 6.3 s due to quick diffusion of powder resulted by fire plume risen from high temperature fire smoke as well as thermophoretic force,resulting from different temperature grads within air in the single room.Because of the diffusion retardation of SFFEP by the shelter,shelter fire could only be extinguished in a longer time,i.e.about 14.3 s.Fire extinguishing time was influenced by powder concentration.Though center fire,comer fire and shelter fire could be extinguished by 500 g SFFEP,the fire extinguishing time has all been prolonged,about 8.1 s,13.9 s and 22.2 s,respectively.For ceiling fire,it could not be extinguished even though SFFEP could diffuse and arrive at the ceiling at the action of fire plume and thermophoretic force.This is because fire extinguishing agent concentration has become low and oxygen concentration was high due to decreasing oxygen consumption speed following the extinguishment of other fire sources in the single room.In the contrast,the combustion reaction speed became higher due to the increase of temperature.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第2期209-212,共4页
Journal of Safety and Environment
关键词
安全工程
超细微粒灭火剂
单室火灾
灭火时间
safety engineering
superfine fire extinguishing powder
single room fire
fire extinguishing time
