地铁轨道区火灾场景特性研究

Study on fire scenarios characteristic for subway fire in railway section

在考虑人为恐怖袭击行为情况下,采用地铁轨道区模型实体火灾试验研究了地铁轨道区的火灾场景。得出了模拟地铁轨道区在火灾中的热释放速率,烟气浓度,温度,烟密度的变化规律。通电模拟短路以致引燃方式着火的最大热释放速率为9.66kW。浇洒煤油方式点火,轨道区最大热释放速率达到了204kW。随着电缆的点燃,燃烧进行的较为缓慢,烟气上升至隧道顶,沿着顶部向开口外扩散。CO2的浓度变化较为缓慢。至10’41"达到CO2释放峰值5027.7ppm;至10’41"时CO浓度达到最大354.0ppm。在轨道区间燃烧过程中,高温烟气始终沿着隧道顶部扩散,低于1.5m的空间是相对安全的;高于1.7m的空间是相对危险区域。火灾中烟气是首先弥漫整个房顶,然后再往下漫延的。

Taking into account the arson terrorism, the fire scenarios characteristic of subway fire had been studied by substantiality model of subway railway section. The change rule of heat release rate, smoke concentration, temperature and smoke density had been educed. We can get the conclusion that the most heat release quantity under the short circuit condition achieved at 9.66kW and that of coal oil ignition was 204kW. With burn processing, the concentration of both CO2 and CO was slowly raised. Until 10＇ 41″, the concentration of CO2 achieved the highest value 5027.7ppm, and at the same time the concentration of CO achieved the highest value 354.0ppm. During fire, smoke and gas suffused all of booth roof firstly, then pervaded to floor.