摘要
为探究隧道内对称双火源燃烧行为特征及温度分布情况,搭建1∶6的缩尺寸隧道模型实验台,开展隧道双火源燃烧实验,研究火源间距、横向偏距及火源尺寸等对燃料的质量损失速率、热释放速率、火焰形态、火焰高度及烟气最高温度分布情况的综合影响。结果表明:燃料的质量损失速率、热释放速率及火焰高度与横向偏距、火源间距均呈负相关关系。当无量纲火源间距S/D≤1时,双火羽流融合,顶棚下方最高温度曲线图仅有1个温度峰值;随着火源间距的增大,烟气最高温度分布由“单峰”变缓,向“双峰”过渡,当S/D≥4时,双火源基本独立燃烧,最高温度曲线图呈现2个温度峰值;近火源区域无量纲最大温升与无量纲横向偏距呈指数衰减关系。建立近火源区域最大温升预测模型,并与实验数据对比验证了其可靠性。该研究可为隧道内多火源火灾防排烟系统设计和应急救援提供参考。
[Objective]Multisource fire accidents frequently occur in tunnels,and their combustion characteristics are complex,influenced by both the parameters of the source itself and air entrainment and thermal feedback of adjacent fire sources.The combustion characteristics of multisource fires are related to the size,fuel type,and spacing of neighboring sources.In a dual-source fire in a tunnel,adjacent dual sources may compete for air,leading to flame merging.During flame merging,special flame phenomena occur,such as flying fire and fire whirlwinds,increasing the probability of fire spread and the degree of danger.Thus,building a reduced-size tunnel model to systematically analyze the evolution mechanism of multisource fire behavior is necessary.[Methods]Herein,we built a 1:6-scaled tunnel model and conducted scaled experiments to investigate the dynamic evolution characteristics of restricted symmetric dual-source fire in natural ventilation tunnels under different fire source spacings.We studied the combustion rate,flame morphology,flame fusion,and ceiling temperature distribution.In particular,the ceiling temperature was further divided into near-and far-fire-source regions.We aimed to reveal the evolution of an asymmetric entrainment mechanism involving flame tilting and the fusion of a restricted symmetric dual-source fire in a tunnel.In addition,we constructed a quantitative model for the highest temperature rise of symmetrical dual-source fires under different fire source spacings and lateral offset distances.Thus,the dynamic characteristics of the tilting or even fusion of a restricted symmetric dual-source fire were elucidated.[Results]This study found that the mass loss rate,heat release rate,and flame height were negatively correlated with the lateral offset distance and fire source spacing.When the dimensionless distance between the fire sources(S/D)was less than or equal to l,flame fusion occurred,and a peak temperature occurred below the ceiling.As the distance between fire sources increased,the maximum t
作者
陈荣芳
郭志国
刘祖文
周令剑
杨雨润
谭清岚
CHEN Rongfang;GUO Zhiguo;LIU Zuwen;ZHOU Lingjian;YANG Yurun;TAN Qinglan(School of Emergency Management and Safety Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,China;National-Local Joint Engineering Laboratory of Water Engineering Safety and Efficient Utilization of Resources in Poyang Lake Watershed,Nanchang Institute of Technology,Nanchang 330099,China)
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第9期1608-1616,共9页
Journal of Tsinghua University(Science and Technology)
基金
国家自然科学基金项目(52264018)
江西省教育厅科学技术项目(GJJ210825)。
关键词
隧道火灾
双火源
横向偏距
燃烧行为
温度分布
tunnel fire
dual-source fire
lateral offset
combustion behavior
temperature distribution
