地铁出入段线防排烟系统设计方案优化研究

Optimization of the Smoke Control Strategy for the Access Tunnels of the Metro

对于地铁出入段线防排烟系统设计方案,常采用在靠近洞口处设置射流风机辅助排烟的方式,这种方案中射流风机的配电成本远高于射流风机本身成本。采用FDS数值模拟方法,研究郑州地铁10号线出入段线隧道5种防排烟系统设计方案的隧道风速和排烟效果,并对各方案进行经济性分析。研究结果表明:作为非载客区间的出入段线,其排烟风速低于2m/s时仍可满足有组织排烟的要求;取消洞口处射流风机,仅采用出入段线所接车站的4台60 m^(3)/s事故风机,仍可较好地控制该出入段线隧道火灾烟气,防止火灾烟气威胁车站的运营安全,不影响地铁列车司机的安全撤离;条件允许时可以在出入段线靠近车站侧设置一组射流风机,用于加强排烟效果、提高运营安全水平;同时,火源靠近车站时,靠近出入段线侧两台事故风机比其余事故风机晚启动30 s,可以有效改善车站隧道内烟气滞留的问题。

Jet fans are often used to increase longitudinal ventilation velocity in the smoke control system of subway access tunnels.The cost of the power distribution system of the jet fan is much higher than that of the jet fan in the smoke control system of subway access tunnels.The tunnel ventilation velocity and smoke exhaust effect for five smoke control strategies for the subway access tunnel of the Zhengzhou metro line 10 were investigated using the fire dynamics simulator(FDS)numerical simulation method.The economic analysis of the five smoke control strategies was also conducted.Numerical simulation results showed that tunnel ventilation velocities<2 m/s can meet the requirements of smoke control in the access(no-passenger section)tunnel.Four 60 m^(3)/s emergency fans can meet the tunnel smoke exhaust needs of the subway access tunnels in the smoke control system without jet fans at access tunnel portals.The smoke control system without jet fans at access tunnel portals can prevent smoke and threaten the safety of station operation.The short smoke back-layering length will not affect the safe evacuation of metro train drivers.If the installation conditions permit,a group of jet fans is recommended to be installed at the station side of the subway access tunnels,which can improve the tunnel ventilation velocity and smoke exhaust effect.To solve the problem of smoke retention in station tunnels,it is proposed that the two emergency fans at the subway station sides of the access tunnels are activated 30 s after the activation of the other fans.