纵向风条件下竖井横截面积对排烟效果的影响

The Influence of Cross-sectional Area of Vertical Shaft on Smoke Emission under Longitudinal Wind Condition

用火灾模拟软件FDS考察了纵向风条件下竖井横截面积对排烟效果的影响。结果表明:烟气层吸穿和烟气边界层分离都影响竖井内烟气的运动,从而影响排烟效果。从分析结果看,随着纵向风速的增大,烟气层发生吸穿时的竖井尺寸增大。纵向风速较大(v≥1. 5 m/s),竖井尺寸较小(1 m×1 m),烟气边界层分离不突出;纵向风速小(v≤0. 5 m/s),竖井尺寸大(2. 5 m×2. 5 m,3 m×3 m),烟气边界层分离也不突出。

The software of fire dynamics simulator(FDS) is applied to examine the influence of cross-sectional area of vertical shaft on smoke emission under longitudinal wind condition.The results show that both smoke layering plugholing and smoke boundary layer separation affect the movement of smoke in the shaft,thus affecting the smoke extraction.According to the analysis results,with the increase of longitudinal wind speed,the size of the shaft increases when the smoke layering plugholing occurs.When the longitudinal wind speed is large ( v ≥1.5 m/s)and the vertical shaft size is small (1 m×1 m),the smoke boundary layer separation is not obvious.When the longitudinal wind speed is small ( v ≤0.5 m/s) and the vertical shaft size is large (2.5 m×2.5 m,3 m×3 m),the smoke boundary layer separation is not obvious either.