地铁上盖车辆基地运用库机械排烟效果试验研究

Experimental study on the mechanical smoke exhaust effect of the operation depot of the vehicle base above subway

通过实体热烟试验,研究地铁上盖车辆基地运用库内的烟气蔓延规律,对比分析不同排烟工况下烟气的扩散速度、烟气温度和烟气层高度,并对机械排烟系统的实际排烟和控烟效果进行现场验证。试验结果表明,运用库内发生火灾后,即使在机械排烟系统的有效作用下,烟气也不能完全被限制在着火区域所在防烟分区内,而是不断向周围扩散蔓延,并在远离火源的区域冷却沉降;提高排烟量,虽可减缓烟气扩散蔓延的速度,但仍无法将烟气全部限制在着火防烟分区内,同时增加排烟系统排烟量对降低烟气温度的效果并不明显。从各工况中烟气层的高度变化情况可知,在设有机械排烟系统的情况下,单位面积排烟量分别为44.8、29.1、16.7 m^(3)/(h.m^(2))时,烟气层均能被控制在较高的高度(约7 m),可为初期人员疏散和灭火救援提供有利条件。

Realscale hot smoke experiments were conducted to study the smoke spread characteristics in an operation depot of subway vehicle base.The smoke propagation velocity,smoke temperature,and height of the smoke layer in the depot under different smoke exhaustion conditions were compared and analyzed.The smoke control and exhaustion effects of the mechanical smoke exhaust system has also been verified on site.The test results show that,in case of fire occurred in the depot,even if the mechanical smoke exhaust system activated and performed effectively,the smoke could not be completely confined within the smoke prevention zone where the fire started.The smoke would spread out from the original zone,cool down and descend in the area away from the fire source.Increasing the exhaust volume could decrease the propagation rate of smoke,but the smoke could not be confined completely within the fire smoke protection zone.Besides,increasing the exhaust volume has little effect on reducing the temperature of smoke layers.As shown in the tests,the smoke layer could be maintained at a relatively ideal height(about 7 m),when the mechanical smoke exhaust system was properly activated(the smoke exhaust volume was 44.8,29.1 or 16.7 m³/(h.m²),respectively).The smoke exhaust system could provide favorable conditions for occupant evacuation and fire rescue operation in the initial stage once a fire occurs in the subway operation depot.