建筑火灾中回燃现象的临界条件实验研究

回燃是在通风受限的建筑火灾进入缺氧燃烧甚至闷烧后，由于新鲜空气的突然大量补充引起热烟气急剧燃烧的现象。回燃现象由于其突然性和强大的破坏性威胁着人类的安全，特别是消防人员的安全。为了研究建筑火灾中回燃现象的临界条件，建立了一套小尺寸回燃实验装置，并进行一系列的实验；实验结果表明：腔体内的燃料质量分数是回燃的决定性参数，当它达到某个临界值时，回燃必然产生。

Experimental study of critical condition of backdraft phenomenon in building fires

Backdraft phenomenon is the fire phenomenon in vitiated buildings where the hot gas rapidly combusts due to abruptly supply of abundant fresh air after combustion with lack of oxygen or even smoldering. Backdraft phenomenon is apparently a hazard to the safety of people, especially firefighters for its abruptness and its destructive power. A scaled backdraft experimental apparatus was introduced and a series of experiments results were discussed in order to study the critical condition of backdraft phenomenon in building fires. The experimental results show that the key parameter determining the occurrence of backdraft is fuel/air in compartment. When fuel/air ratio exceeds a critical value, backdraft will take place.