支路隧道坡度对地下立交分岔隧道烟气扩散特性影响的模拟  

Numerical simulation of the smoke spreading in the urban road tunnels with the grade dividing junctions

作　　者：李俊梅[1] 刘闪闪[1] 李炎锋[1] 常军[2] 李雁[2] 陈超[1] 

机构地区：[1]北京工业大学建筑工程学院,北京100124 [2]北京市市政工程设计研究总院,北京100082

出　　处：《安全与环境学报》2016年第3期55-61,共7页Journal of Safety and Environment

基　　金：国家自然科学基金面上项目(51278018);北京市自然科学基金面上项目(8132011);"十二五"国家科技支撑计划项目(2012BAJ01B03)

摘　　要：通过数值模拟对地下互通立交隧道的典型结构-分岔隧道处烟气的扩散特性进行了研究。分析了火源位于分岔路段上游时,下游支路隧道坡度及火源功率对主、支路隧道烟气质量流量分配及烟气温度分布的影响。结果表明:火源功率一定时,随下游支路隧道坡度增大,火灾中产生的烟气会更多地流向火源下游,并流入支路隧道,上游主隧道内的烟气温度降低;火源功率除影响产烟量及隧道内的温度分布外,对主、支路隧道的烟气质量分配影响较小。The paper is inclined to present a numerical simulation of the smoke propagation in the urban road tunnels with the gradedividing functions.As compared with the smoke spreading in the tunnels with a single entrance and exit,things tend to be more complicated with the smoke spreading in the underground road tunnels with the grade-dividing junctions,for there may exist more heat to be released,that is,the heating releasing rate（HRR） of the fire,the slope of the branch tunnels,the angle formulated between the main tunnel and the branch tunnels,the ratio of the cross-section between the main tunnel and the branch tunnels constitute all the likely factors that may impact the smoke releasing.Seeing the above said influential factors,we have made great efforts in exploring the problems of smoke mass flow distributions between the downstream main tunnel and branch tunnels at the junction sections.The fire is supposed to be located at the upstream of the junction section,where there may exist four kinds of the fire-heat releasing rates,that is,those of 5 MW,10 MW,20 MW and 30 MW to be analyzed respectively,with four corresponding grades of the downstream branch tunnels,that is,those of 0,3%,6% and 9%.The results show that with the increase of the branch tunnel slopes,more smoke tends to be entering into the downstream tunnels,especially into the downward branch ones.Statistically speaking,almost about 75% of the smoke tends to enter and move towards the downstream tunnels whereas about 9% is motivating in the slope of the branch tunnels.However,about 60% of them is likely to pass through the branch tunnels.In such a situation,the temperature under the ceiling in the upstream main tunnel may turn to be decreasing,with little change of the temperature in the downstream tunnel being observed.With more smoke flowing into the downstream branch tunnels,the temperature in the branch tunnel goes to increase.At this,the smoke layers are likely to get blurred,which can be dangerous for the passengers or workers to move out from

关 键 词：安全工程 地下道路 烟气扩散 数值模拟 立交分岔 

分 类 号：X928.7[环境科学与工程—安全科学]