坡度对隧道火灾烟气温度分布的影响  

Impact of slope on smoke temperature distribution in tunnel fires

作　　者：赵红莉[1] 徐志胜[1] 李洪[1] 姜学鹏[1] 李冬[1] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2013年第10期4257-4263,共7页Journal of Central South University:Science and Technology

基　　金：铁道部科技研究开发计划项目(2006G007-A-1;2006G007-C-1)

摘　　要：从能量守恒的角度出发,建立预测隧道火灾烟气沿程温度变化的理论模型,研究坡度对隧道烟气温度的纵向衰减和最高温度的影响。并通过缩尺寸火灾模型试验进一步研究隧道坡度对火灾烟气温度分布的影响规律,共考虑0%,1%,2%和3%4种坡度。并将试验数据与烟气温度的理论模型预测值进行对比,验证其可靠性。试验结果表明:烟气自由蔓延时,无论沿隧道下坡方向还是隧道上坡方向,与火源相同距离处的烟气温度变化与坡度近似呈线性关系;随着坡度的增加,隧道下坡方向的烟气温度降低,隧道上坡方向的烟气温度则逐渐升高,但温度变化幅度不大;当纵向通风风速较大时,不同坡度间的温度差异性逐渐降低;隧道坡度的存在,既有可能加速燃烧,也有可能降低热量。Based on conversation of energy, a theoretical model was derived to predict the longitudinal distribution of the smoke temperature in tunnel fires, the effect of the tunnel gradient on the smoke temperature distribution was studied. The variations of the smoke temperature in tunnel fires with the tunnel gradient were studied through reduced-scale fire tests, and four slopes of 0%, 1%, 2% and 3% were taken into account. Moreover, the experimental results of smoke temperature were compared with the predictions of theoretical model. The results show that the variations of the smoke temperature at the same distance from the fire source with the tunnel slope can be approximately approached by a linear line under on ventilation, both in downhill and uphill directions of tunnel. The smoke temperatures below the ceiling in downhill direction decrease with larger tunnel slopes, but the smoke temperatures in uphill direction of tunnel increase at a low rate. When the longitudinal ventilation velocity is rather large, the smoke temperature differences among tunnels with different slopes are reduced. The presence of tunnel slope can lead to the possibilities of accelerating the fuel burning as well as reducing the heat in tunnel.

关 键 词：坡度 隧道火灾 烟气温度 缩尺寸试验 

分 类 号：U459.2[建筑科学—桥梁与隧道工程]