隧道内横向偏置火源火灾烟气温度特性全尺寸试验研究  

Full-scale Experimental Study on Smoke Temperature and Fire Characteristics Occurred at Deflected Positions in Tunnels

作　　者：胡嘉伟[1] 毛军[1] 刘斌[1] 林振瑶 郗艳红[1] 李桂强 郭汝杰 HU Jia-wei;MAO Jun;LIU Bin;LIN Zhen-yao;XI Yan-hong;LI Gui-qiang;GUO Ru-jie(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Shenzhen Transportation and Public Facilities Construction Center,Shenzhen 518040,Guangdong,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]深圳市交通公用设施建设中心,广东深圳518040

出　　处：《中国公路学报》2020年第11期205-214,共10页China Journal of Highway and Transport

基　　金：国家重点基础研究项目(2016YFC0802206);国家自然科学基金项目(51578061);深圳市建设工程科研课题(BYTD-KT-002);中央高校基本科研业务费专项资金项目(2019JBM087)。

摘　　要：为了研究隧道内火灾温度分布规律和烟气运动状态,使交通隧道火灾灾害降到最低,通过全尺寸隧道火灾试验研究了热释放速率为30MW火源位于偏离横向中心位置一个车道宽度条件下的顶棚射流的烟气温度特征,分析了烟气在各阶段的温度分布以及沿横向和纵向扩散的规律。结果表明:在火源下游一定区域内,偏置火源火灾产生的烟气在沿隧道横向和纵向扩散温度分布均呈非对称形态;烟气继续沿纵向扩散一段距离后,逐渐出现和形成温度分层;偏置火源顶棚射流的温升趋势随时间呈二次多项式关系增长,远壁面烟气沉降高度和温度衰减幅值大于相应中心火源的试验值;与中心火源的相似,火源在下游30m内的顶棚射流温升随纵向距离的增加符合指数衰减规律,但同时还受到偏置距离的影响;可使用量纲一的偏距与量纲一的纵向距离的函数关系式描述其分布规律。The aim of this study was to analyze fire temperature and smoke movement in a tunnel to minimize a fire disaster.Previous researches mainly focused on the fire source located in the central section of the tunnel.However,in this study,full-scale tunnel fire tests with a heat release rate of 30 MW were conducted in a city road tunnel.The characteristics of ceiling jet temperature were studied with the fire source located one lane width away from the center line.The temperature distribution of smoke in each stage was analyzed along with the law of transverse and longitudinal diffusion.The results show that for the deflected fire source in the tunnel,smoke diffusion,and temperature distribution are asymmetrical in a certain area downstream from the fire source.After the smoke continue to diffuse longitudinally along the tunnel,it gradually forms a temperature stratification state.The rise in ceiling jet temperature of the deflected fire source increases with the quadratic polynomial relationship.Compared to the central fire source test,the smoke settlement height and temperature attenuation amplitude near the far sidewall are greater.Within 30 m downstream from the fire,the ceiling temperature follows an exponential decay,affected by the deflected distance and longitudinal distance,a uniform stratification occurring along the vertical direction.The isothermal layer is asymmetrical on the side away from the sidewall.The dimensionless transverse deflected distance and longitudinal distance can be used to describe the distribution law.

关 键 词：隧道工程 温度分布 全尺寸火灾试验 烟气扩散 偏置火源 

分 类 号：U458.1[建筑科学—桥梁与隧道工程]