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为揭示挡烟垂壁对狭长通道火灾烟气特征及温度分布的影响,运用火灾动力学软件FDS,研究了狭长通道内不同高度挡烟垂壁下火灾烟流运动行为,重点探讨了密度跳跃过程及近火源区烟气特征参数变化。结果表明:挡烟垂壁增加了密度跳跃中翻滚区的长度,缩小了卷吸空气范围,造成烟气质量流率相应减少;挡烟垂壁对烟气垂直速度分布的影响主要作用在挡烟区,且与垂壁高度有关;垂高大于0.3 m,受挡烟垂壁高度影响,在垂直高度1.5~2 m位置出现一定速度的烟气逆流,速度分布曲线呈现与无挡烟垂壁不同的凹陷区,非挡烟区烟气垂直速度服从高斯分布;与无挡烟垂壁相比,挡烟垂壁上游顶棚附近温度普遍增高,下游温度衰减速率随挡烟垂壁高度的增加而加快。
In order to reveal the influence of the smoke blocking vertical wall on the smoke characteristics and temperature distribution of the narrow channel fire, the fire dynamics software FDS was used to study the smoke movement behavior under the smoke curtain wall with different height in the narrow channel. The density jumping process And the characteristics of flue gas near the source zone. The results show that the wall of the smoke block increases the length of the rollover zone in the density hopping and narrows the entrainment air range, resulting in a corresponding decrease in the mass flow rate of the flue gas. The influence of the smoke drop wall on the vertical velocity distribution of flue gas mainly affects the smoke blockage And the height of the vertical wall. The vertical height is more than 0.3 m. Due to the height of the vertical wall of the smoke retaining wall, a certain velocity flue gas countercurrent occurs at a vertical height of 1.5-2 m. The velocity distribution curve is different from that of the vertical wall. The vertical velocity of flue gas in non-retaining area obeys Gaussian distribution. Compared with the vertical wall without blocking smoke, the temperature near the ceiling of smoke retaining wall generally increases, and the rate of temperature decay in the downstream accelerates with the height of retaining wall .