半封闭公交枢纽火灾安全研究

Study on fire safety of a semi-closed public transportation hub

针对综合交通枢纽中的半封闭公交枢纽部分出入口少、车辆与人员混杂产生火灾风险问题,以某实际半地下公交枢纽为研究对象,研究极端火灾场景即枢纽中心处公交发生火灾时烟气扩散情况。采用现场出入口实测数据作为边界条件,选择快速t2火且最大功率为30 MW模拟公交车辆火灾场景。采用大涡模拟软件FDS分析开启排烟风机和不开启风机工况下枢纽内烟气扩散情况。研究表明:枢纽的中心处发生公交车辆火灾时,开启枢纽内的防排烟系统能够在6 min中内保证人员的安全疏散。考虑枢纽高度对烟气层沉降的影响,半封闭高大空间公交枢纽防排烟系统设计可以参考国内地下车库的防排烟系统相关设计规范。

Fire safety of a semi-enclosed public transportation hub in a comprehensive transportation center was analyzed. Smoke propagation under an extreme fire scenario where fire occurred at the center of the hub was studied.On-site measured data at portals were set to the boundary conditions in a numerical simulation. A quick t2 fire model with a maximum heat release rate of 30 MW was used to simulate a bus fire. Large eddy simulation technology was used to predict smoke propagation under two fire scenarios,where smoke exhaust fans operated or not. Results show that operation of a smoke control system could provide safe evacuation within six minutes when a fire occurred in the center of the hub. Given such results,domestic underground garage smoke control system design specifications should be considered for semi-enclosed spaces such as transit hubs.