开式通风系统作用下深埋地铁区间隧道火灾的性能化分析

Analysis on the Performance of Interzone Tunnel Fire in Deeply-Buried Subway under the Effect of the Open Ventilation System

目的分析中部风井对深埋地铁区间隧道火灾烟气蔓延的影响,以及中部逃生井正压送风作用下逃生井的安全疏散性状,为深埋地铁工程的性能化防火设计提供理论支持.方法采用火灾动力学软件(FDS)进行数值模拟,采集烟气温度、浓度等参数,分析开式通风系统作用下火灾烟气蔓延的规律.结果当在深埋地铁区间隧道中部附近设置排烟风井时,烟囱效应作用加强了烟气通过风井的自由出流,降低了隧道内烟气浓度及温度,可以为人员疏散争取一定的时间.结论深埋地铁区间隧道中部逃生井采用正压送风措施,很好地抑制了隧道火灾烟气的蔓延态势,可以充分满足人员安全疏散的要求.

The project is to study the effect of intermediate shaft on the spread of fire smoke in the interzone tunnel in deeply-buried subways, safe evacuation performance with intermediate escape shaft associated with positive pressure air supply, and to provide valuable theoretical support for the subway engineering project design based on the performance of fire safety. Fire dynamics simulator （FDS）is applied to simulate mass concentration of fire smoke and smoke temperature, and smoke spread law is analyzed under the open venti- lation system in a tunnel of deeply-buried subway. The results indicate that the tunnel smoke concentration and temperature are reduced when the smoke exhaust shaft are established near the centre of interzone tun- nel, which can get more time for safety evacuation. Furthermore, when positive pressure air is supplied in the intermediate shaft, it can fully satisfy safe evacuation conditions for evacuees. The research result also indi- cate when positive pressure air is supplied in the intermediate escape shaft, it can fully control the spread of fire smoke in the tunnel and satisfy safe evacuation conditions for evacuees.