阻塞效应下地铁隧道烟气蔓延特性研究  

Numerical simulation for the smoke spreading features in subway tunnels under the condition of blocking effect

作　　者：翟利华 农兴中 何冠鸿 谢宝超[3] 徐志胜[3] 王婭芳 赵家明 ZHAI Li-hua;NONG Xing-zhong;HE Guan-hong;XIE Bao-chao;XU Zhi-sheng;WANG Ya-fang;ZHAO Jia-ming(Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510000,China;Key Laboratory of Road and Traffic Engineering of Ministry of Education,Tongji University,Shanghai 201804,China;Institute of Disaster Prevention Science and Safety Technology,Central South University,Changsha 410075,China)

机构地区：[1]广州地铁设计研究院股份有限公司,广州510000 [2]同济大学道路与交通工程教育部重点实验室,上海201804 [3]中南大学防灾科学与安全技术研究所,长沙410075

出　　处：《安全与环境学报》2020年第3期930-937,共8页Journal of Safety and Environment

基　　金：国家重点研发计划项目(2017YFB1201204);广州市轨道交通十八号线及二十二号线超长大区间防灾救援专题研究项目;广州市轨道交通十八号线及二十二号线带上盖开发段场盖下防灾救援专题研究项目。

摘　　要：阻塞效应下地铁隧道烟气蔓延特性研究对隧道火灾烟气控制方案的制定有重要影响。采用火灾动力学软件FDS6. 4,对阻塞效应下地铁区间隧道内的拱顶下方最高温度、纵向温度衰减和烟气回流规律进行了数值模拟研究。结果表明,已有隧道拱顶最高温度预测模型并不适用于高阻塞比条件下隧道拱顶最高温度的预测,提出了隧道拱顶最高温度依赖于火源热释放速率、纵向通风条件及阻塞比时的最高温度预测模型。在火源下游温度衰减系数范围为[0. 197 1,0. 223 2];在火源上游,纵向通风速度越大温度衰减越快,且温度衰减系数与无量纲纵向通风速度呈线性增长关系。The given paper aims to provide a reference pattern to the smoke control system design as well as a theoretical basis for the service of the emergency rescue. To achieve the goal,we have done a full-scale model of circular shield tunnel through the software known as FDS 6. 4 for numerical simulation with a discussion on the smoke propagation features in the subway tunnel in case takes place the blocking effect. In proceeding with our study,the variation trend of the 3 parameters,i. e. the maximum temperature,the longitudinal temperature distribution and the smoke back-layering length under the tunnel ceiling may all have a significant influence on the given topic. On the other hand,we have also set different dynamic pressure values at the entrance of the tunnel to simulate the different longitudinal velocities. The results of our simulated test indicate that the maximum temperature in the tunnel tends to be 805. 09 ℃ . What is more,the currently existing model for testing the maximum temperature under the tunnel ceiling is not suitable for the subway tunnels with high blocking ratios. The reason for the case is that,under the ratio of 42%-57% of high blocking,there may exist another novel prediction model of the maximum temperature under the subway tunnel ceiling in case of the fire situation,which is related to the heat release rate,the longitudinal ventilation velocity and the blocking ratio,which has been proposed in correspondence well with the numerical simulation results. That is,at the downstream of the fire source,the temperature attenuation coefficient range should be equal to [0. 197 1,0. 223 2],whereas on the upstream of the fire source,the temperature attenuation coefficient should be equal to [0. 624 3,0. 860 7]. Thus,there may exist an exponential decay and an attenuation coefficient upstream of the fire with the dimensionless velocity between the upstream and the downstream of the fire temperature distribution ratios. And,in turn,it has also been found that the smoke backlayer length tends to dec

关 键 词：安全工程 地铁隧道 阻塞效应 温度衰减 数值模拟 FDS 

分 类 号：X932[环境科学与工程—安全科学]