隧道集中排烟口间距的多目标决策分析  

Analysis of the multiple objective decision of the optimal interval of the exhaust extraction outlets in a centralized tunnel smoke-extraction system

作　　者：刘琪[1,2] 姜学鹏[1] 蔡崇庆[3] 

机构地区：[1]中南大学土木工程学院,长沙410075 [2]湖南中医药大学人文社科学院,长沙410208 [3]中铁第四勘察设计院集团有限公司城市轨道与地下工程设计研究院,武汉430063

出　　处：《安全与环境学报》2013年第2期214-218,共5页Journal of Safety and Environment

基　　金：湖南省科技计划项目(2012GK3169);浙江省交通运输厅科技计划项目(2010H01);灭火救援技术公安部重点实验室开放课题(KF2011003);中南大学中央高校基本科研业务费专项资金项目(2011QNZT109)

摘　　要：在确定具体隧道集中排烟量和排烟口面积后,排烟口间距是影响隧道集中排烟效果的关键因素。为达到最大安全性和最小设施设置成本,以2m高度处烟气温度不超过60℃、2m高度处能见度不小于10m、相对蔓延距离不大于1为安全性决策目标,以总成本最小为经济性决策目标,提出隧道集中排烟系统排烟口设置间距的多目标分析方法。用基于大涡模拟的FDS软件对不同排烟口间距下的隧道火灾烟气流动特性进行模拟计算。给定的排烟量为240m3/s,排烟口面积为6m2。疏散环境安全性分析表明,排烟口间距为30～100 m时,2m高度处烟气温度T2m、2m高度处烟气能见度V2m均能满足人员安全疏散的要求;但若间距为70m、80m和90 m,相对蔓延距离值大于1时,烟气无法限制在排烟口打开段范围内,表明这3种排烟口间距为非合理设计。进一步考虑设施设置成本,间距为100m时排烟口设置数量最少,且经济性最好,即该隧道最优排烟口设置间距为100m,火灾时开启4个排烟口。This paper is aimed at presenting three safety decision variables and one economic decision variable for the exhaust outlet interval in the tunnel smoke extraction system in hoping to pursue the maximum safety and minimum economic cost. As is known, the safety decision variables may include the temperature at 2 m height within the temperature range of 60℃, the visibility at 2 m height of the tunnel with the height limit of less than 10 m, and the relative smoke spreading distance over 1 m, with the total cost of exhaust outlets kept minimized. To make our model more practical, we have developed an exhaust outlet interval method based on the multiple objective decision analysis and prepared a simulated model known as FDS 5.0 for the tunnel smoke-extracting system in a cross-river tunnel. In our simulated model, we have laid out nine different exhaust outlets at a heat-releasing rate of 50 MW. The given exhaust rate is 240 m3/s, with the exhaust outlet area being 6 m2. The results of our simulation show that the exhaust outlet intervals between 30 m and 100 m can be expected to meet the demands of the temperature and visibility at 2 m height for the occupant evacuation. However, we have found that when the exhaust outlet interval is 70 m and 80 m and 90 m, the relative smoke spread distances should be over 1, which means that it is impossible to control the smoke emission in the scope of opening exhaust outlets and the three intervals. However, the number of the exhaust outlets in a specific tunnel would be made least and the lowest cost and best economy can be gained if the exhaust outlet intervals were laid out at 100 m. Thus, it can be concluded that 100 m turns to be the optimal exhaust outlet intervals, with four outlets being opened in case of a tunnel fire.

关 键 词：安全工程 公路隧道 排烟口间距 多目标决策 集中排烟系统 

分 类 号：U453.5[建筑科学—桥梁与隧道工程]