不同火源面积下隧道火灾温度场试验与数值模拟分析  

Experimental and Numerical Simulation Analysis of Temperature Field of Tunnel Fire with Different Fire Source Areas

作　　者：陈长坤[1] 王玮玉[1] 康恒[1] 史聪灵[2] 刘晅亚 CHEN Chang-kun;WANG Wei-yu;KANG Heng;SHI Cong-ling;LIU Xuan-ya(Institute of Disaster Prevention Science and Safety Technology, Central South University, Changsha 410075, Hunan, China;Beijing Key Laboratory of Metro Fire and Passenger Transportation Safety, China Academy of Safety Science and Technology, Beijing 100012, China;Key Laboratory of Building Fire Protection Engineering and Technology of MPS, Tianjin 300381, China)

机构地区：[1]中南大学防灾科学与安全技术研究所,湖南长沙410075 [2]中国安全生产科学研究院地铁火灾与客流疏运安全北京市重点实验室,北京100012 [3]建筑消防工程技术公安部重点实验室,天津300381

出　　处：《中国公路学报》2018年第6期235-243,共9页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51576212;51622403;51534008);建筑消防工程技术公安部重点实验室开放项目(KFKT2014ZD02)

摘　　要：为了探究隧道内不同火源面积下温度场的分布规律,给隧道火灾救援提供科学的理论支持,为隧道防火设计提供参考,建立1∶9的缩尺寸模型隧道,对3种不同火源面积下,隧道火灾的热释放速率、拱顶及纵断面温度场分布特征、隧道洞口火溢流分布特点进行试验研究。同时采用大涡模拟方法对以上3种火灾场景进行了数值模拟计算,并利用试验对模拟结果进行对比分析。研究结果表明:当火源面积较小时,空气充足,燃烧主要以燃料控制型为主,隧道内最高温度位于火源正上方,并沿隧道纵向向两端逐渐减小,温度分布稳定、分层明显,此时通过火灾模拟软件FDS得到的数值模拟结果与试验较为吻合;当火源面积较大时,空气较为不足,燃烧主要以通风控制型为主,在稳定燃烧阶段,火源中部的燃烧因通风受限而受到抑制,其温度明显降低,而火源两侧燃烧相对剧烈,温度较高;当燃烧进入衰减阶段,由于两侧可燃蒸气减少,火源中部因助燃物充足而再次剧烈燃烧,此时,FDS数值模拟结果能够较好反映出该场景下的燃烧情况,但相对于试验,模拟计算所获得的温升速率较快,在充分燃烧阶段火源中心的抑制作用较试验更为明显;隧道洞口火溢流的模拟结果与试验结果相一致,数值模拟能够更好地给出火羽流的结构细节。In this study,a 1/9 scaled tunnel was established,and experiments and numerical simulations were carried out using the LES method for three different fire source areas to investigate the distribution rules of temperature in a tunnel exposed to fire and provide a reference for tunnel fire protection design and rescue.The distribution characteristics of temperature along the tunnel ceiling and cross-section,as well as the heat release rate and the behaviors of fire overflow at the tunnel entrance were determined and analyzed.The experimental and numericalresults indicate that small area tunnel fire is mainly controlled by the fuel owing to the relatively abundant air,and the temperature at the center of the combustion region is significantly higher than the temperature at the two sides and it continues to decrease along the longitudinal direction.Furthermore,the temperature distribution is stable and obvious stratification occurs.It was found that the simulation results of FDS and the experimental results are in good agreement.For large area tunnel fire,the combustion is mainly controlled by the ventilation owing to the relatively abundant air supply,and the fire intensity at the middle of the combustion region decreased owing to limited ventilation and lack of oxygen;thus,the temperature decreased,while fire on both sides is relatively intense.As burning on both sides enters a weak phase,flammable vapors on both sides are reduced,and fuel in the middle of the combustion region burns intensely again owing to the abundant air supply.In this case,the simulation by FDS can also reflect the development of the fire.However,the simulation results indicate that the rate of increase of the temperature in the tunnel is higher and the combustion inhibition effect is more evident in the middle of the combustion region at the developing stage of the combustion.In addition,the growing trend of fire overflow of FDS is essentially consistent with the experimental results,and the simulation results can provide further details of f

关 键 词：隧道工程 隧道火灾 试验研究 数值模拟 温度场 火源面积 

分 类 号：U458.1[建筑科学—桥梁与隧道工程]