正压送风和室外风综合作用对住宅建筑着火房间火灾发展的影响

Effect of Combined Positive Pressure Ventilation and Outdoor Wind on Fire Development in a Fire Room of Residential Building

利用火灾动力学模拟软件FDS,建立着火房间的物理模型,模拟研究不同正压送风风速对处于迎风风速2 m·s^(-1)的着火房间火灾发展的影响。结果表明:正压送风时,火灾热释放速率先增后降,最终稳定在30 MW左右;正压送风可以降低送风口处的温度,降低火灾蔓延至走廊的危险性,但风机风速过大会导致通过排烟口截面的热流量过大,可能导致火灾向窗外蔓延。综合考虑,当室外风速2 m·s^(-1)时,对迎风面着火房间正压送风,宜选择10 m·s^(-1)左右的风机风速。

FDS was used to establish a physical model of the fire room. And it was used to simulate the effect of diferent positive pressure ventilation wind speeds on the fire development in the fire room with outdoor wind speed 2 ？ s 1. The results showed that fire heat release rate increased first and then decreased unner the connition of postive pressure ventilation , eventually stabilized at about 30 MW. Positive pressure ventilation could reduce the temperature at the air outlet , and it could reduce the risk of fire spreading to the corridor. However , too large winspeed could cause excessive heat flow through the window （exhaust port） . And it could cause the fire spread out thwindow. In comprehensive consideration ： when the outdoor wind speed is 2 m s^-1 , it is fan speed of about 10 m s^-1 to use the positive pressure ventilation in the windward fire room.