基于大涡模拟的地铁区间火灾横向温度分布研究

Study on lateral thermal distribution of subway section based on LES

对不同纵向通风速率、火源功率以及截面形状下地铁隧道内横向温度分布特性进行模拟研究。结果表明:火源功率越大,升温速度越快,但烟气层以下的壁面温度分布大致不变;纵向通风对衬砌表面温度分布有明显影响,纵向风速较小时,衬砌顶部温度最高,中部次之,地面最低,而纵向风速达到3m/s时,由于火源被吹倾斜,导致火源下游附近衬砌顶部温度最高,地面次之,中部最低的分布特性。同时,研究了隧道截面形状与温度分布的关系。

The lateral thermal distribution of subway section was simulated under different longitudinal ventilation velocities, fire powers and cross-section shapes. The results showed that the temperature rise rate is faster as fire power gets bigger, but the temperature below smoke layer is stable; the longitudinal ventilation has significant effect on fining surface temperature, when the longitudinal ventilation velocity is small, the temperature presents a decreasing tendency from lining top to the middle to the ground, while the velocity gets to 3 m/s, as to fire goes sideway with the wind, the temperature presents a decreasing tendency from lining top to the ground to the middle. Meanwhile, the relationship between cross-section shape and temperature distribution was discussed.