Smoke distribution in naturally ventilated urban transportation tunnels with multiple shafts  

多竖井自然通风城市公路隧道火灾烟气分布(英文)

作　　者：童艳[1] 施明恒[2] 翟志强 

机构地区：[1]南京工业大学城市建设与安全工程学院,南京210009 [2]东南大学能源与环境学院,南京210096 [3]Department of Civil Environmental and Architectural Engineering,University of Colorado at Boulder

出　　处：《Journal of Southeast University(English Edition)》2013年第3期305-309,共5页东南大学学报（英文版）

基　　金：The National Natural Science Foundation of China(No.51178217);the Natural Science Foundation of Jiangsu Province(No.BK2011804)

摘　　要：The smoke spreading law of urban transportation tunnels with multiple shafts under natural ventilation is studied.A full-scale burning experiment is conducted in an actual tunnel.The study shows that smoke temperatures below the tunnel ceiling reduce rapidly along the longitudinal towards the tunnel exits. A noticeable temperature stratification is observed near the fire source.Most fire smoke is exhausted out of the shafts while the number of the smoke shafts in the downstream is more than that in the upstream.Large eddy simulation LES based on computational fluid dynamics CFD is carried out using the fire dynamics simulator FDS software with parallel processing in which the grid size of the fire-domain is set to be 0.083 m.The simulation results of temperatures under the ceiling the smoke fronts and the shafts＇smoke exhaust or air supply agree reasonably with the experimental data. Further simulations indicate that the decreasing ambient temperature or shaft spacing might reduce smoke temperatures under the tunnel ceiling and increase mass flow rates out of the shafts.This study provides technical scientific evidence and supports for the design and construction of such kinds of tunnels.研究了多竖井城市公路隧道自然通风条件下的火灾烟气扩散规律.在某真实隧道内实施了全尺寸燃烧试验,试验过程中顶棚下方烟气温度沿纵向朝出口快速衰减,火源附近存在明显的烟气分层现象,大量烟气从竖井排出,下游排烟竖井个数多于上游.使用FDS火灾软件开展基于计算流体动力学的大涡模拟,火源区网格尺寸为0.083 m.采用并行计算技术,模拟得到的顶棚下方烟气温度、烟气前锋、竖井进/排烟均与试验数据吻合较好.进一步的数值模拟结果表明:降低环境温度或竖井组间距有助于降低顶棚下方烟气温度,同时提高竖井出口的排烟质量流量.本研究为该类隧道的设计与修建提供了理论与技术支持.

关 键 词：TUNNEL natural ventilation multiple shafts largeeddy simulation smoke spreading 

分 类 号：TU834[建筑科学—供热、供燃气、通风及空调工程]