通风对泡沫-水喷雾系统灭火有效性影响分析

Experimental studies on the effect of longitudinal ventilation on suppression effectiveness of the water-foam spray system in tunnel fire

为了探究隧道发生火灾后,其内部通风排烟系统的开启是否会对自动喷水系统的灭火效果产生影响,本文通过全尺寸试验的方法,针对20 MW的木垛火和油池火,对隧道内以临界风速送风时的火灾场景进行了研究,同时研究了火源上方存在遮挡以及通风和灭火开启时序的影响。研究结果表明:通风可以降低隧道内的顶棚温度,提高隧道内的能见度,在一定程度上可以提高自动灭火系统的灭火效率。当固态火源上方存在遮挡时,通风系统后启动会局部加大火势,使灭火时间增长。对于运输碳氢类固态货物的车辆火灾,通风系统先于灭火系统开启或通风和灭火系统同时开启的灭火效果较好。

The question of whether the opening of a tunnel’s internal ventilation and smoke exhaust system will affect the fire extinguishing abilities of the automatic water spraying system after a fire occurs was investigated.The fire scene in a well-ventilated tunnel,with a critical wind speed for a 20 MW wood pile fire and oil pool fire by the full-scale burning test method,was examined.The influence of shelter above the fire source,and the opening time sequence of ventilation and fire extinguishing,was also investigated.Results showed that ventilation reduced the ceiling temperature in the tunnel,improved visibility,and improved the fire extinguishing efficiency of the automatic fire extinguishing system,to a certain extent.For the solid fire with top shield,the ventilation system started later than for the water-foam spray system.This increased the fire locally and prolonged extinguishing time.For fires in vehicles transporting hydrocarbon-based solid goods,the ventilation system is started earlier,or simultaneously with the fire extinguishing system,to get better fire suppression efficiency.