关于轰燃定义、机理和判据的讨论与分析

通过对常见的几种轰燃定义的对比分析，对轰燃进行了新的定义，认为轰燃是室内火灾发展到一定阶段引起非连续介质着火燃烧的现象；在此基础上，根据燃烧学原理提出了轰燃发生的机理，即可燃挥发份和高温烟气层接触发生的剧烈氧化还原反应；并提出了预测轰燃的通用判据，即火灾时室内其它可燃物热解产生的可燃挥发份迅速和空气混合，达到其着火浓度下限且接触到超过可燃物自燃点的高温烟气层。

Discussion and analysis on definition, mechanism and criterion of flashover

Several common definitions of flashover are compared and analyzed, and a new definition is giv- en. Flashover is defined as a phenomenon where discrete objects are ignited when enclosure fires develop to a certain degree. Based on combustion theory the mechanism of flashover is presented, i.e. a severe oxida- tion-reduction reaction happens when combustible volatiles meet hot smoke layer. Then a universal criterion for predicting flashover is proposed, i.e. the combustible volatiles generated from other combustibles under fire circumstance mix rapidly with air, reach the minimum concentration and contact with the hot smoke lay- er whose temperature is beyond its self-ignition point.