阻塞比对地铁区间隧道火灾半横向排烟方式排烟效果的影响研究

Study on Influence of Blockage Ratio on Smoke Exhaust Effect of Semi-horizontal Smoke Exhuast Mode in Subway Tunnel Fire

列车在不同高度的地铁区间隧道中行驶时,会形成不同的阻塞比(列车的横断面积与隧道横断面积的比值)。论文利用FDS(Fire Dynamics Simulator)数值模拟软件建立了同一列车在3种不同高度隧道中形成不同阻塞比的模型。在隧道内发生火灾时,在每种阻塞比下改变排烟风速,对能够反映半横向排烟方式排烟效果的隧道内烟气蔓延情况、人眼特征高度处的温度和CO浓度、顶棚温度等各项指标变化规律进行模拟和分析,并总结不同阻塞比下排烟风速的改变对半横向排烟方式排烟效果的影响,以及时对排烟条件作出调整,达到更好的排烟效果,为地铁区间隧道的排烟系统设计提供了参考。

When a train runs in a subway tunnel with different heights,There are different blockage ratios （the ratio ofthe cross sectional area oft.he train to the cross section of the turmel）.In this paper, FDS numerical simulation software was used to establish three models with different blockage ratios for the same train in the tunnel with three different heights. When the fire occurred in the tunnel, under each blockage ratio, changing the speed of smoke exhaust, the smoke spreading speed in the tunnel,the temperature and the CO concentration at eye characteristic height which reflecting semi-transverse smoke exhaust effect were simulated and analysed.ln addition, the influence of the change of smoke exhaust speed under different blockage ratios on the smoke exhaust effect of the semi-horizontal smoke exhaust mode was summarized, so as to adjust to the smoke exhaust condition and achieve better smoke exhaust effect .The paper is beneficial to design of smoke exhaust system in subway tunnels.