长大纵坡公路隧道火灾人员疏散的合理通风风速研究

Study on the Suitable Ventilation Velocity for Fire Personnel Evacuation of Highway Tunnel with Longitudinal Long Slope

为探明交通拥堵状态发生火灾情况下,纵向通风风速对长大纵坡公路隧道人员疏散环境的影响,从而明确满足火灾工况人员疏散的合理风速,采用数值模拟对不同通风风速、不同纵坡坡度条件下,隧道内拱顶位置和人眼特征高度位置的烟气分布特性及变化规律进行研究和分析。结果表明:1)随着通风风速的增加,在火源上游,不同坡度隧道内特征高度的最高温度均逐渐下降;在火源下游,上坡隧道内特征高度的最高温度先下降后升高,而下坡隧道内特征高度的最高温度先升高后下降;2)满足人员疏散的风速随隧道坡度的增大而有所减小,火灾规模为30 MW时,坡度为-2%、-1%的隧道人员疏散合理风速分别为2.5 m/s和2.0 m/s,坡度为1%的隧道人员疏散合理风速为1.0 m/s~1.5 m/s,坡度为2%的隧道人员疏散合理风速为0.5 m/s~1.5 m/s。

In order to find out the influence of longitudinal ventilation velocity on evacuation environment of highway tunnel with long longitudinal slope in the case of congestion caused by tunnel fire,and determine the suitable velocity for personnel evacuation under fire condition.Numerical calculation method was used to simulate the distribution and variation of smoke temperature under ceiling as well as at eye characteristic height under different ventilation velocity and longitudinal slope.The results show that:1)The maximum temperature of characteristic height at the upstream of the fire decreased gradually for tunnel with different slope with the increase of ventilation velocity,.As for the the maximum temperature of characteristic height at the downstream of the fire,it increased after an initial decline with the increase of ventilation wind speed for tunnel with uphill slope,and it increases rapidly but then decreases for tunnel with downhill slope;2)The suitable velocity for personnel evacuation declined as the tunnel slope increased.When the fire scale is 30 MW,the suitable velocity is 2.5 m/s for the tunnel with-2%slope,and 2.0 m/s for the tunnel with-1%slope.The suitable velocity is suggested to be 1.0~1.5 m/s for the tunnel with 1%slope,while it is 0.5~1.5 m/s for the tunnel with 2%slope.