地铁隧道列车火灾的火焰顶棚射流温度特性研究  

Analysis of the characteristics of the flame ceiling jet temperature due to train fire in subway tunnels

作　　者：毛军[1] 郗艳红[1] 樊洪明[2] 

机构地区：[1]北京交通大学,北京100044 [2]北京工业大学,北京100022

出　　处：《土木工程学报》2010年第2期119-126,共8页China Civil Engineering Journal

基　　金：国家科技部重大基础研究前期专项研究项目(2005CA04700);北京交通大学科技项目(2006XM026)

摘　　要：以地铁隧道火灾为研究对象,通过1∶8缩尺模型试验和数值模拟分析夹带火焰的烟气顶棚射流的温度特性,为地铁隧道火灾的防灾减灾提供参考。假定火源位于列车中部,燃烧强度是经过相似变换的等量荷载。火焰直接撞击顶棚并向上、下游扩展。考虑隧道内热辐射效应,得到在不同燃料用量下火焰顶棚射流温度的时变规律与空间分布特征。结果表明:燃料的多少对火焰顶棚射流在燃烧时间内的温度时变曲线的变化趋势影响不大,燃烧达到稳定的时间非常接近,但稳定状态的温度明显不同;火焰区上方顶棚射流烟气的最高温度与燃料液面的高度有关,试验中出现在距隧道顶0.18H处,而不是纯烟气顶棚射流给出的0.01H的区域内;列车上方及列车首尾附近的火焰顶棚射流温度沿隧道纵向呈线性衰减,且衰减速率不随时间变化,而不是纯烟气顶棚射流的指数衰减形式。在一定的高度以下,火焰顶棚射流的温度迅速降低,存在温度较低的安全区域适合于人员疏散。The characteristics of the flame ceiling jet temperature due to fire in subway tunnels was analyzed by using a 1：8 scale model experiment and numerical simulation to provide references for disaster prevention and mitigation. It was assumed that the fire source was at the center section of the train. Fire heat release rate was the equivalent load after similitude transformation. Flame hit directly on the ceiling and expanded upstream and downstream along the ceiling. With heat radiation effects considered,temperature variation with time and space were obtained for different levels of fuel consumption. It was found that fuel consumption had little effect on the trend of the time-varying temperature during the combustion with similar stability time but different stability temperature. The maximum temperature above the flame was related to the height of the fire source,at 0.18H under the tunnel ceiling rather than 0.01H as for the pure gas ceiling jet. Different from the exponential attenuation for the pure gas ceiling jet,the temperature of the flame ceiling jet near the train was linearly attenuated along the tunnel,but the attenuation rate was almost identical. Only in regions where the flame could not reach,the gas temperature was exponentially attenuated with a large gradient. At certain height below the ceiling,the temperature descended quickly and there was a low temperature region existed for security evacuation.

关 键 词：地铁隧道 列车火灾 火焰 顶棚射流 数值模拟 模型试验 

分 类 号：U458[建筑科学—桥梁与隧道工程]