火灾工况下公路隧道竖井通风模式试验研究

为了建立火灾工况下有效的竖井通风模式,通过大比例火灾模型试验,对不同通风模式下,主隧道、风道及竖井内温度场的传播分布、烟流蔓延扩散规律进行了研究。试验模型隧道长100 m,内径1.8 m,设有直径1 m的送风竖井、排风竖井各一座。火源采用燃烧床盛放油料模拟,试验中设定了A、B、C三个火灾规模用以模拟实际隧道火灾场景,考虑了三个火灾位置:火灾位置I、II和III。试验结果表明随着通风风速、火灾规模、火灾位置的不同,隧道、通风道及竖井内温度场分布及烟流流动差异很大,而且随着时间的推移,其分布发生显著变化。这表明当隧道中发生火灾时,应根据火灾点与竖井的相对位置分阶段,实施不同的通风模式。基于试验结果,建议了秦岭隧道火灾时的有效通风模式。

Experimental study of shaft ventilation modes for road tunnels in case of fire

To establish an effective ventilation mode for fire fighting in the Qinling road tunnel,an experiment is carried out to study the temperature distribution and smoke propagation in the ventilation duct and shaft of the tunnel in case of fire..The model tunnel is 100 m long,has a circular cross-section with an inner diameter of 1.8 m.Two ventilation shafts with a diameter of 1 m are constructed.An oil pool is employed as the source of fire.Three fire loads and three fire locations are employed to simulate different fire scenarios.The results indicate that the temperature distribution and smoke propagation vary significantly with different fire loads,fire locations,ventilation modes and fire stages in the tunnel,the ventilation duct and the shaft.These phenomena suggest that different ventilation modes,in case of fire,should be considered in order to show a consistent effect with the fire locations and fire stages.Based on the results of the experiments,an effective ventilation mode is established for fire fighting in the Qinling tunnel.