公路隧道火灾烟气横向温度分布规律研究

Study on transverse temperature distribution of fire smoke in highway tunnel

为了研究公路隧道火灾烟气横向温度分布规律,通过小规模公路隧道模型模拟火灾试验,对不同面积火灾下横向和纵向烟气温度分布、不同火灾位置下横向烟气温度分布进行了分析,研究结果表明:当火灾距离侧壁0.65 m时,温度上升的横向衰减率大于纵向衰减率,烟气流纵向扩散时,部分烟气在侧壁向下移动形成回流,而横向扩展无阻拦;在火灾过程中,烟气在隧道顶部远离火灾时,其温升呈指数级下降,当火源与左侧壁距离为1.05 m,火源面积长×宽为24 cm×24 cm时,隧道在距左侧壁1.05 m位置横向烟气温度最大;在火灾过程中,将实验测量的横向烟气温升分布与计算结果对比,确认计算结果符合现场火灾测量情况,能极好地预测横向烟气温升分布。

In order to study the transverse temperature distribution law of fire smoke in highway tunnel,the paper analyzes the transverse and longitudinal delay temperature distribution under different fire areas and the transverse smoke temperature distribution under different fire locations through simulating fire test of small-scale highway tunnel model.The research results are clear:The results shows:when the fire is 0.65 m away from the side wall,the transverse attenuation rate of temperature rise is greater than the longitudinal attenuation rate.When the flue gas flows towards the side wall,part of the flue gas moves downward to form a backflow,and the lateral expansion is not hindered;in the process of fire,when the smoke is far away from the fire at the top of the tunnel,its temperature rise decreases exponentially.When the distance between the fire source and the left side wall is 1.05 m,and the area of the fire source is 24 cm×24 cm,the transverse smoke temperature reaches the maximum at 1.05 m from the left side wall;In the process of fire,the measured transverse flue gas temperature rise distribution is compared with the calculated results,and the calculated results are in line with the field fire measurement,which can predict the transverse flue gas temperature rise distribution very well.