室内步行街三级排烟效果试验研究

Experimental study on effect of three-tier smoke exhaust in indoor pedestrian street

为研究三级排烟模式且顶部设有自然排烟窗的室内商业步行街火灾烟气蔓延特性,在步行街首层环廊位置进行热态发烟试验。结果表明:相比于两级排烟,三级排烟模式下环廊排烟可有效阻止烟气蔓延至步行街高大空间;一旦发生小规模火灾或产生低热量烟气时,步行街顶部采用机械排烟方式比自然排烟方式具有明显的排烟效果,但排烟风机的延迟开启易造成烟气蔓延范围扩大。为了营造安全的疏散条件,避免烟气从环廊蔓延至步行街,应增大环廊排烟设备的能力。

Aiming at smoke spread in an indoor commercial pedestri an street with three-tier smoke exhaust and natural smoke exhaust window on the ceiling, the hot smoke test was conducted at the corridor of the first floor. The results showed that compared to twotier smoke exhaust mode, corridor smoke exhaust could effectively prevent smoke spreading to the large space of pedestrian street un- der three-tier smoke exhaust mode;in case of a small fire or iow heat smoke, smoke exhaust effect was better under mechanical smoke exhaust than under natural smoke exhaust on the ceiling, however, delayed open of smoke exhaust fans could expand the range of smoke spread. Meanwhile, in order to create a safe evacu ate condition and avoid smoke spreading from corridor to pedestrian street, the capacity of smoke exhaust equipment in corridor should be increased.