大型地铁换乘站多点火灾情况下的烟气扩散研究

Study on smoke propagation in a large subway transfer station with a multi-point fire scenario

分析研究地铁换乘站火灾烟气扩散的技术难点。以东直门换乘站车站为例,利用数值模拟手段研究站台和换乘大厅同时发生火灾的极端情况,得出该工况下的换乘站内重要出入口以及换乘通道内的烟气扩散速度以及温度分布。通过现场冷烟试验测得的换乘站典型断面风速数据以验证相应试验工况的数值模拟结果,从而验证数值模拟方法的合理性。研究表明:数值模拟研究大型地铁换乘站火灾扩散规律具有较高的可靠性;多点火灾时在换乘站部分出入口区域形成烟气互串现象,会严重影响人员的安全疏散。

The difficulties in numerical simulation of fire scenarios in a large subway transfer station are analyzed.An extreme dangerous situation where fires happen in both station and transfer hall in a typical subway transfer station,Dong Zhimen transfer station,in Beijing is studied.The smoke temperature and velocity fields in transfer channel and exits are computed.The numerical simulation is validated by comparison between the results of spot tests without hot smoke and those of a comprehensive numerical simulation condition.It can be found that numerical simulation is a reasonable method for studying smoke propagation in a large subway transfer station.Under a multi-point fire scenario,smoke intervolve can happen in certain exits.This would do harm to safety evacuation in subway station.