地铁全封闭声屏障自然排烟仿真研究  

Numerical Simulation on the Natural Smoke Exhaust of Fully-enclosed Noise Barrier for Subway

作　　者：刘磊 康钟绪[2] 张良焊 吴瑞[2] 户文成[2] LIU Lei;KANG Zhongxu;ZHANG Lianghan;WU Rui;HU Wencheng(Beijing Urban Construction Design&Development Group Co.,Limited,Beijing 100037,China;Beijing Municipal Institute of Labour Protection,Beijing 100054,China)

机构地区：[1]北京城建设计发展集团股份有限公司,北京100037 [2]北京市劳动保护科学研究所,北京100054

出　　处：《铁道标准设计》2020年第11期168-175,共8页Railway Standard Design

摘　　要：基于流体动力学的三维数值仿真方法,研究地铁全封闭声屏障的自然排烟性能。以实际某地铁高架全封闭声屏障结构为基本研究对象,仿真研究顶部通长开口方案下不同火源强度时的烟气扩散性能,并研究声屏障内火灾排烟过程的时空特征以及平行和垂直声屏障方向环境风对排烟的影响,最后研究开口面积降低后,周期开口、无开口的全封闭声屏障方案的排烟性能。研究表明:在有顶部通长开孔的情况下,环境冷空气从两侧顶部开口进入声屏障并携带烟气通过顶部开口释放,烟气在声屏障内的扩散范围较小,6 min内的烟气扩散过程均不会影响火源两侧及另一侧轨道空间作为人员疏散通道;火源强度增大后对声屏障内烟气和温度影响范围的影响不大;不同方向环境风对烟气的扩散影响明显,平行环境风有利于烟气的扩散,垂直环境风对烟气的扩散有抑制作用;顶部改为周期开口方案,开口投影面积比5%,间距50 m,高温烟气主要通过附近的开口释放,声屏障顶部聚集的烟气厚度有所增厚,但仍不能对高1.5 m的平面产生明显影响,火源两侧和另一侧轨道空间仍可作为安全的人员疏散通道使用;无开口方案的排烟性能受声屏障长度影响,长度超过200 m部分区域的高温烟气已经达到地面,高度1.5 m处水平面温度大部分已超过65℃,无法满足安全要求。A three-dimensional numerical simulation method based on fluid dynamics is used to study the natural smoke extraction performance of fully-enclosed noise barrier for subway.The elevated fully-enclosed structure of actual noise barriers in a subway is taken as the basic research object.Simulation research on the performance of gas diffusion with different fire intensity under top long open scheme is conducted,and the characteristics of space and time in the process of fire smoke exhaust in the noise barrier and the effect of the environmental wind from the parallel and vertical direction of noise barrier on the smoke are studied.Finally,the smoke extraction performances of the full closed noise barrier with periodic opening and no opening are studied after the opening area is reduced.The research shows that,in the case of the top opening in the long axis,the cold air in the environment enters the noise barrier from the top opening on both sides and carries the smoke to release through the top opening.The diffusion range of smoke in the noise barrier is relatively small.The smoke diffusion process within 6min will not affect the track space on both sides of the fire source and the other side as personnel evacuation channel.The influence of the intensity of fire source on the influence range of smoke and temperature in the noise barrier is not significant.The influence of the ambient wind in different directions on the diffusion of flue gas is obvious.The parallel ambient wind is beneficial to the diffusion of smoke,while the vertical ambient wind inhibits the diffusion of smoke.The top is changed to the periodic opening scheme,with 5%projected area ratio of the opening and 50 m spacing.The high temperature smoke is mainly released through the nearby opening,the thickness of smoke concentrated on the top of the barrier is increased.However,it still cannot have a significant impact on the 1.5 m high plane,and the track space on both sides of the fire source and the other side can still be used as personnel evacuation

关 键 词：地铁 全封闭声屏障 自然排烟 数值计算 CFD 

分 类 号：U231.96[交通运输工程—道路与铁道工程] TU112.59[建筑科学—建筑理论]