基于多目标约束的地铁长区间隧道排烟方案优化

Optimization of smoke extraction model based on the multi-objective constraint in metro long tunnels

为探究地铁长区间隧道设置侧边局部排烟道工程中保证人员安全疏散的排烟方案的判据,结合济南黄河隧道的结构特点,通过理论分析探讨了分段排烟道不同开启方式、列车追踪情况下的烟气控制有效性判定准则。选取最不利工况,利用FDS数值模拟软件构建1∶1等比例的侧边局部排烟道长区间隧道模型,研究了隧道火灾温度场、流速场及疏散平台能见度等分布特性,多方位地判断各种通风排烟方案的烟气控制效果。结果表明:烟气控制有效性的四准则适用于侧边局部排烟道地铁长区间隧道;根据烟气控制四准则定量得到了侧边局部排烟+纵向通风排烟模式下的人员安全疏散评估模型;使用优化评估模型验证了最不利工况下排烟方案设置的合理性。

Currently,there is no safety evaluation standard for personnel evacuation in the mode of side concentrated smoke exhaust and longitudinal ventilation smoke exhaust of subway long-interval tunnel.Therefore,according to the structural features of subway long-interval tunnel and fire characteristics and in combination with the mode of lateral smoke exhaust and longitudinal ventilation smoke exhaust,this paper gave a set of evaluation models.According to the setting of flues section by section,the train running in a tunnel and the ventilation control principle of only one train running in each section and combination with the actual engineering,this paper put forward ten smoke exhaust schemes of different fire scenes for different fire locations.According to the personnel evacuation requirements of metro interval in case of fire,this paper provided four smoke control rules of lateral concentrated smoke exhaust and longitudinal ventilation smoke exhaust mode.In accordance with the long and narrow confined structure space of subway long-interval tunnel and the characteristics of a large amount of smoke,rapid spreading,high temperature,light reduction,etc in case of fire and based on the four smoke control rules,this paper put forward the ventilation and smoke exhaust system of long-interval rail traffic tunnel for the first time and provided several evaluation indexes for smoke exhaust wind speed,smoke spread range,visibility,and temperature at the clear height of evacuation platform 2.0 m.This study analyzed the distribution rule of fire temperature field,flow field,visibility,etc of rail traffic using software numerical simulation FDS.Besides,an optimized evaluation model of ventilation and smoke exhaust strategy based on multi-index constraints of safe evacuation and effective smoke exhaust was developed.The evaluation model was applied to 10 fire scenarios for verification.The result shows that the smoke exhaust schemes under different fire scenarios can guarantee the evacuation safety of personnel in the upwind environment.