地下车库连通道非平直上坡段防排烟设计

Smoke control design of non-flat uphill sections in channel connect underground garage

某地下车库主通道为单向2车道,采用横向通风系统,换气次数按10次/h设计,补风量为排烟量的85%。排烟口尺寸0.8m×0.5m,距离地面3.5m,每25m设置一个。设置5MW的火灾,分两种排烟方案,使用CFX与FDS对烟气流动模拟计算。起火272s后主通道内人员疏散完毕,比较此时两种排烟方案下各防烟分区的温度分布、CO2浓度、风速矢量可知,方案二排烟效果优于方案一。在较大火灾情况下两种排烟方案控烟效果均不理想,建议限制通道内火灾荷载。

The main channel of an underground garage, two-way two-lane, has transverse ventilation system, the air changes 10 times per hour, and the make-up air is 85% of smoke ventilation. The exhaust port is 0.8 m×0.5 m of the size, 3.5 m from ground, set every 25 m. The smoke movement was simulated by CFX and FDS with 2 smoke exhaustion plans under 5 MW fire. The people in main channel can finish evacuation 272 s after the ignition, so the temperature distribution, concentration of CO2 and vector of wind velocity were compared under 2 smoke exhaust plans. The results showed that the plan 2 is better than plan 1. Restrict the fire load in channel was suggested since both of the plans were not good enough when the fire is bigger.