侧向排烟城市道路隧道的水幕阻烟隔热性能研究

为探究侧向排烟城市道路隧道的水幕阻烟隔热作用，并为隧道的水幕设计和消防疏散提供参考，使用FDS软件对水幕模型进行数值模拟计算。在8 MW的火灾规模下，研究隧道顶部2个喷头和4个喷头2种布置方式，0.08、0.1、0.25、0.4 MPa 4种水喷头工作压力、侧向排烟量大小、排烟口间距和数量等主要因素对隧道水幕阻烟隔热性能的影响，分析比较烟气扩散范围、温度及能见度的变化规律，评估隧道疏散救援环境。结果表明： 水幕系统能抑制隧道内烟气的扩散，阻止隧道温度过快上涨，并能改善隧道内的能见度； 水幕系统在排烟量增加、排烟口间距减小、排烟口数量增加的情况下，阻烟隔热性能更明显； 水幕系统对隧道内能见度的改善作用只维持于火灾发生的前中期，后期效果将减弱，因此消防救援工作应在火灾发生的前中期开展。

Smoke and Heat Insulation Performance of Water Curtain  in Urban Road Tunnel with Lateral Exhaust

In order to explore the smoke and heat insulation performance of water curtain in unban road tunnel with lateral exhaust, and provide reference for water curtain design and fire evacuation, numerical simulation of water curtain model is conducted by FDS. Under the fire scale of 8 MW and considering the double/four nozzle layout on tunnel top, the influences of factors, i.e. the pressures of water sprayhead of 0.08 MPa, 0.1 MPa, 0.25 MPa and 0.4 MPa, the amount of smoke exhaust, distance between exhaust vents and number of exhaust vents, on smoke and heat insulation performance are studied; the variation laws of exhaust scope, temperature and visibility are analyzed and compared; and the evacuation environment of tunnel is evaluated. The results show that: (1) The water curtain system weakens the spread of smoke in the tunnel, prevents the tunnel temperature from rising too fast and improves the visibility of the tunnel. (2) The water curtain system is more effective in insulating smoke and heat as the amount of smoke exhaust increases, the distance between exhaust vents decreases and the number of exhaust vents increases. (3) However, the effect of water curtain on tunnel visibility improvement only keeps in the early and middle stages of the fire, and the effect will weaken in the later period. Therefore, it is necessary to carry out fire rescue work in the early and middle stages of the fire.