超高海拔隧道火灾燃烧与烟气温度现场模型试验研究

Field model experimental study on fire combustion and smoke temperature in very-high-altitude tunnels

随着我国川藏铁路和高原公路的不断修建,超高海拔地区"三低"环境特征将对高原隧道火灾燃烧和烟气扩散特性产生严重影响。文章采用移动模型隧道火灾试验平台对成都平原、海拔3544m、4103m超高海拔山区在相同油盘尺寸和燃料体积条件下,火灾燃烧和烟气温度分布进行现场试验研究。研究结果表明:随着海拔高度的增加,火灾热释放率和火源区拱顶温度不断下降,燃烧时间明显增长;与平原地区相同火灾规模相比,超高海拔隧道火源区拱顶温度略有下降;超高海拔地区拱顶纵向温度衰减速率显著低于平原地区,火灾高温烟气热浮升力效应在超高海拔隧道内更突出。

With the development of Sichuan-Tibet railway and highway at high altitudes, it is believed that "three low" environmental characteristics of very high altitudes may greatly affect the fire combustion and smoke spread in tunnels.A moveable model tunnel is transported to different altitudes, such as Chengdu Plain, mountains with altitudes of 3544 m and 4103 m, to study the fire combustion and smoke temperature distribution with the same pool size and volume.The results show that HRR(heat release rate) and smoke temperature on the top decrease significantly with the increase of altitude, but the combustion duration tends to be longer.The smoke temperature on the top at very high altitudes is slightly lower than that in plain with the same HRR.The longitudinal smoke temperature on the top decays more slowly at very high altitudes.The effect of buoyancy appears to be much more prominent in very high altitude tunnels.