变风量排烟系统对地下汽车库火灾疏散安全性的影响

摘要

FDS is used to simulate and analyze the development of vehicle fires and the human evacuation safety in underground garage based on the analysis of the following parameters in fire scenario, such as the changes of the heat release rate, the average temperature, and concentrations of carbon dioxide on the Z = 1.8 m plane in central corridor under different conditions of mechanical exhaust ways. The results show that, the Variable Air Volume (VAV)exhaust system has better control effectiveness to the fire temperature and smoke than the Scheduled Air Volume ( SAV ) exhaust system has, and the heat release rate with VAV is sharply decreased between 250 s and 350 s, and the safety evacuation performance of exit is also increased.For the garage, when air circulation ratio is changed from 30 times/h to 40 times/h at 300 s, the effect of smoke evacuation is the best.%目的 研究变风量排烟系统对地下汽车库火灾的控制效果.方法 采用火灾动力学软件FDS(Fire Dynamic Simulator)对某地下汽车库火灾进行数值模拟研究,对不同工况下的火灾释热速率和中央通道1.8 m高度处的平均温度、二氧化碳体积浓度以及人员疏散安全性进行了对比分析.结果 与定风量排烟系统相比,变风量排烟系统对火场温度和火灾烟气有很好的控制效果,250 s～350 s时火灾释热速率有大幅下降,疏散出口安全性有所提高.结论 对于该车库,300s时将排烟量从30h换气次数增加到40次时,排烟效果最佳.