中文摘要：

地铁站台发生火灾时,屏蔽门的开关模式对站台火灾烟气流动的影响至关重要。运用FDS软件对某地铁站台进行数值仿真计算,分析了不同端门开闭模式下火灾烟气的温度、扩散区域、沉降高度、在楼扶梯开口处的流速及可用安全疏散时间等特征参数,并对屏蔽门火灾模式进行了验证。结果表明：端门开启模式下,在站台两端区域及楼扶梯开口处火灾烟气均沉降至危险高度,不利于人员安全疏散;端门开启模式使烟气加速向站台两端纵向流动,但不能及时排出,导致烟气在站台两端区域加速混合与沉降,地铁工程不宜采用此种模式。

英文摘要：

The given paper intends to take a by-floor metro station with an island platform as the case study sample in hoping to disclose the secret of the platform fires via the numerical simulation model with the FDS software platform screen doors（PSD）.For the said purpose,we have to choose a subway station fire by tracing the critical effect of the smoke plume flow pattern in case of the fire.For instance,we have chosen the power of 2.4 MW luggage fire load for the numerical analysis below,when the source of such fires is set up with the medium speed growth at the most unfavorable positions of the platform.In so doing,we have arranged the testing points close to the PSD on the both sides of the platform and the stairs passage as its middle.At the same time,we have also taken the four entrances as the natural ventilation openings in the structured grids,with the grid of the station platform being of much more significance.Using the large eddy simulation（LES） algorithm,we have chosen to take the simulation time for six minutes and the manually-controlled secondary door（MSD） model as the target to be controlled.And,then,we have analyzed the characteristic indexes,such as the smoke temperature,the diffusion area,the setting-down height,the speed of the floor escalator openings and ASET in different MSD models so as to verify the availability of the PSD fire mode.The results of our simulated tests and experiments show that there does exist the dangerous smoke sedimentation height at the ends of the platform and the floor escalator openings in the said MSD model,which fails to meet the demands of the safety evacuation.What is more,the MSD model tends to accelerate the smoke move in the longitudinal derection to the ends of the platform,failing to lead the exhaust smoke to get out in time.In so doing,it may lead to accelerate the mixing and setting-down of the smoke in the areas near the ends of the platform,which is clearly signifying that the aforementioned MSD model fails to satisfy the need of the metro project