隧道内大巴车火灾热释放率及温度场研究

摘要

Bus fires are a common source of fires that occur in tunnels and are a huge threat to the safety of the tunnel structure and related personnel.An elaborate numerical simulation model of a bus is established considering the different combustion characteristics of the bus body,seats,decorations and baggage.For fires occuring at the bus head,middle part or back seat,the temperature field,heat release rate(HRR)and characteristics of the fire are ana-lyzed.The HRR calculation formula is obtained by superimposing a Boltzmann curve on a Gaussian curve.The re-sults show the peak and average values of a bus HRR are 48 MW and 8.1 MW,respectively,and the released energy due to combustion is 14.5 GJ; the maximum burning temperature reaches 1 040℃and the temperature near the door can reach 60℃after 120 sec.The temperature rises fastest at the bus door when the fire occurs at the rear of the bus and it has a high chance of detonating the fuel tank.%大巴车火灾是常见的一种隧道火灾,其对隧道结构稳定,尤其是人员安全构成了巨大威胁.文章考虑车身、座椅、内饰、行李等材料的不同燃烧特性,建立精细化大巴车燃烧数值模拟模型.通过对比车辆从前、中、后座位处引燃3种工况,对大巴车的火源热释放率(HRR)、温度场以及火灾规律进行了研究.采用玻尔兹曼曲线叠加高斯曲线拟合方法得到了大巴车HRR计算公式.研究结果表明:大巴车热释放率峰值可达48 MW,平均热释放率为8.1 MW,燃烧释放能量为14.5 GJ;燃烧最高温度达1 040℃,车门处120 s可达到60℃,从后部点燃车门处升温快,且最易引爆油箱.