隧道集中排烟速率对排烟口下方烟气层吸穿现象的影响  

On the effect of the under-side plugholing on the extraction rate in the central extraction system in the tunnels

作　　者：姜学鹏[1,2,3] 袁月明[4] 李旭[4] 

机构地区：[1]武汉科技大学资源与环境工程学院,武汉430081 [2]中国科学技术大学火灾科学国家重点实验室,合肥230026 [3]北京工业大学建筑工程学院,北京100022 [4]中南大学土木工程学院,长沙410075

出　　处：《安全与环境学报》2014年第2期36-40,共5页Journal of Safety and Environment

基　　金：中国博士后科学基金项目(2013M540830);中国科学技术大学火灾科学国家重点实验室开放课题(HZ2013-KF01);北京市博士后科研活动经费资助项目(2013ZZ-02)

摘　　要：以水平公路隧道为研究对象,运用FDS进行数值模拟,分析了集中排烟模式下对称开启的6个排烟口下方的烟气蔓延规律、烟气层温度和厚度分布规律。结果表明,当排烟速率增大到一定程度时,隧道集中排烟系统存在多个排烟口下方烟气层吸穿的现象,且离火源越远的排烟口越容易发生吸穿,而吸穿会降低整个排烟系统的排烟效率,可能导致排烟口烟气拥堵,易对疏散救援造成消极影响。通过定量描述烟气层厚度和温度与排烟速率之间的关系,获得排烟口下方吸穿的排烟速率范围。The given paper is aimed at studying the effects of the plugholing of multi-exhausts on the different extraction rates under the central extraction system in the road tunnels. It is known that in current studies, little attention has been paid by the scholars to the plugholing of the multiple exhausts. However, for the underground tunnels, it is difficult to make the upper smoke layer as stable as the indoor smoke-fire, for the smoke temperature in the process of horizontal spreading is diminishing. In addition, due to the variety of the exhaust holes in the central extraction system, the smoke exhausting rate of theirs is various too, which has made it indefinite and unexpected for the mechanism and the influential factors of the plugholing under the central extraction system. To confirm the scope of plugholing of the critical smoke extraction rates, we have applied a computer model with FDS to analyze the temperature and the depth of the smoke layer, with the smoke spreading rules acting respectively in a horizontal highway tunnel with the central smoke extraction mode with six exhaust openings isolated-separated symmetrically. The computer model we have used is based on a physical model in a ratio of 1：20 spaced along with in a road tunnel. At the same time, we have also simulated the 15 working conditions in the range of 0-0.179 m 3 /s with different extraction rates. The results of our simulation show that the plugholing could occur in the multiple openings when the smoke exhaust rate is increased to a certain extent. The results of our numerical simulation also indicate the openings that are separately located farther away from the fire source may have had the plugholing effects in advance. Additionally, we have also traced the plugholing effect that may lead to the decrease of the smoke efficiency of the whole exhaustion system and the congestion of the exhausts, which is likely to lead to negative impacts on the evacuation. What is more, in the paper, we have also introduced our work in quantitatively d

关 键 词：安全工程 集中排烟 吸穿 烟气层厚度 数值模拟 

分 类 号：U453.5[建筑科学—桥梁与隧道工程]