市域铁路隧道火灾温度特性及耐火极限面积研究

Research on fire temperature characteristics and fire resistance limit area of urban railway tunnels

依托上海市域铁路隧道,采用数值模拟方法对不同通风条件下隧道火灾温度特性及耐火极限面积进行研究,研究结果表明:不同通风条件下,隧道各排测点温度整体以最高温度所在位置呈对称分布;随着纵向通风风速的增加,隧道顶板最高温度逐渐减小;高温区域主要集中在隧道顶板及侧壁处,纵向通风时高温烟气被吹向火源下游,火源下游温度分层紊乱;隧道超耐火极限区域纵向长度随着与中隔墙距离的增大整体呈减小趋势;随着纵向通风风速的增大,隧道纵向超耐火极限范围逐渐减小,隧道超耐火极限区域总覆盖面积也逐渐减小;隧道自然通风0 m/s、纵向通风风速2 m/s和3 m/s时,隧道超耐火极限区域总覆盖面积分别约为544.51、421.41、357.08 m^(2)。

Relying on the Shanghai urban railway tunnel,the numerical simulation method was used to study the fire temperature characteristics and fire resistance limit area of the tunnel under different ventilation conditions.The research results show that:under different ventilation conditions,the temperature of each row of measurement points in the tunnel is distributed symmetrically with the location of the highest temperature;with the increase of the longitudinal ventilation wind speed,the maximum temperature of the tunnel roof gradually decreases;the high temperature area is mainly concentrated on the roof and side walls of the tunnel,during longitudinal ventilation,the high temperature flue gas is blown to the downstream of the fire source,and the temperature stratification downstream of the fire source is disordered;the longitudinal length of the tunnel ultra-refractory limit area generally decreases with the increase of the distance from the middle partition wall;with the increase of the longitudinal ventilation wind speed,the longitudinal super-refractory limit range of the tunnel gradually decreases,and the total coverage area of the tunnel super-refractory limit area also gradually decreases;when the natural ventilation of the tunnel is 0 m/s,and the longitudinal ventilation wind speed is 2 m/s and 3 m/s,the total coverage area of the tunnel beyond the fire resistance limit is about544.51 m^(2),421.41 m^(2)and 357.08 m^(2),respectively.