倾斜隧道内可燃液体连续泄漏漫流特征及其潜在火灾热释放速率试验研究

Experimental study on the spillage characteristics of continuously leaked liquid fuel and potential heat release rates in sloped tunnels

为研究倾斜隧道内可燃液体泄漏漫流引发的潜在火灾危险性,建立了双向坡度可调试验平台,对连续泄漏漫流形态、宽度、面积等特征随隧道坡度的变化规律进行了试验研究;同时开展火灾试验,研究燃料厚度对热释放速率的影响。结果表明:当隧道仅存在纵坡时,随着坡度的增加,液体漫流宽度及面积缩小;当同时存在横坡和纵坡时,液体流向隧道侧墙,漫流长度及面积缩小。液体漫流平均厚度为2 mm,该厚度下可燃液体热释放速率为经典模型计算值的30%~50%。结合上述试验研究,可对隧道内可燃液体连续泄漏漫流潜在火灾热释放速率进行估算。研究结果表明:隧道横坡由1%增加至2%,液体漫流面积可减少约50%,大幅降低潜在的热释放速率。

The paper focuses on the fire risk caused by the spilled liquid fuel in tunnels. The small-scale test platform with adjustable longitudinal and transverse slopes was established to study the spillage profile, spillage width and area. Meanwhile,the fire tests were carried out to investigate the impact of the fuel depth on the heat release rates. The results indicate that under the longitudinal slopes, the spillage width and area decreases as the slopes become great. When there are both longitudinal and transverse slopes, the liquid fuel spills towards the tunnel sidewall, and as a result, the spillage length and area decrease. In addition, the average depth spilled liquid investigated in this work is 2 mm, and the heat release rates of the fuel under this depth is30%~50% of the theoretical values which are obtained by using a deep fuel. Based on the above achievement, the potential heat release rates caused by the spilled liquid fuel fires can be evaluated. The finding is that when the transverse slopes increase from 1% to 2% under a given longitudinal slope of a tunnel, the potential heat release rates of the fires caused by the spilled liquid fuel may be decreased by 1/2.