摘要
为确保非着火列车处于无烟区,长大隧道通常设置中间风井。然而随着城市空间规划日趋严格和跨江越海隧道越来越多,有时难以设置中间风井,点式排烟成为一种有效的替代方案。采用模型试验、数值计算和理论分析研究火源位置和风口尺寸对烟气控制的协同影响,结果表明:当风口长度小于等于0.10 m时,临界排烟量为靠近火源风口所需的排烟量;当风口长度大于0.10 m时,临界排烟量为远离火源风口所需的排烟量。火源逐渐偏离隧道中心时,风口长度的增加先有利于烟气控制,而后对烟气控制具有反作用,风口长度临界值为0.15 m,这是排烟惯性力与由热压引起的水平惯性力竞争的结果。此外,当风口长度小于0.15 m时,最不利火灾位置在C处;当风口长度大于0.15 m时,最不利火灾位置在D处。
This paper investigated the synergistic effect of longitudinal fire location and vent size on the smoke control in the tunnel fire with point extraction ventilation based on 1:10 reduced-scale experiments,numerical simulation,and force analysis of the smoke beneath the vent.Different Heat Release Rates(HRRs),longitudinal fire locations,and vent lengths were also considered.Results show that the critical exhaust rate is not equal to the fire moving away from the tunnel center.The critical exhaust rate is the required exhaust rate of the near-fire vent for a vent length of less than 0.10 m.This is because the horizontal inertia force induced by the heat pressure is strong when the vent length is small.On the contrary,the critical exhaust rate refers to the required exhaust rate of the far-fire vent when the vent length exceeds 0.10 m.This phenomenon results from the smoke in the smoke extraction channel flowing to the far-fire vent,which results in the decrease of the actual exhaust rate of the far-fire vent.Overall,the critical exhaust rate increases with a fire gradually deviating from the tunnel center and decreases with increasing vent length.However,excess vent length can bring an adverse effect on smoke control from the perspective of critical exhaust rate.This is attributed to a large amount of fresh air being exhausted through the large vent,resulting in a decrease in smoke extraction efficiency.Experimental results illustrate that the critical vent length is 0.15 m.Besides,from the view of smoke control,a worst longitudinal fire location related to the vent length is proposed in this paper.Experimental results suggest that the worst longitudinal fire location is C when the vent length is less than 0.15 m,while the worst longitudinal fire location is D when the vent length is more than 0.15 m.
作者
赵鹏
ZHAO Peng(School of Energy Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an 710043,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2024年第2期525-529,共5页
Journal of Safety and Environment
基金
陕西省重点研发计划项目(2023-YBGY-141)。
关键词
安全工程
隧道火灾
点式排烟
最不利火灾位置
风口临界长度
safety engineering
tunnel fire
point extraction ventilation
the worst fire location
critical vent length
