地铁多线换乘车站火灾模型实验研究—(2)十字换乘车站火灾

针对当前地铁十字换乘车站缺少火灾场景系统性分析和评估的问题，釆用1∶10的地铁多线换乘车站火灾实验模型，进行十字换乘车站的火灾场景设计和对应全尺寸火源热释放率0.91~2.60 MW的火灾实验，研究十字换乘车站内站厅及站台危险位置发生火灾时的优化排烟方案。结果表明:站厅一端火灾时，站厅排烟可确保中部换乘通道和站厅另一端楼梯及出口在起火6 min内不受烟气影响；站厅中部火灾时，采用站厅排烟能保障站厅两端楼梯及出口作为疏散通道的安全性。地下2层站台或地下3层站台一端楼梯口发生火灾时，采用站台排烟与站厅送风联动的模式可控制烟气在站台内的扩散范围，确保站台未起火楼梯和站厅层在起火6 min内能够作为安全疏散通道；仅采用站台排烟可以控制烟气在站台内水平方向的扩散，但在火源功率较大时烟气会通过换乘通道和楼梯进入站厅。通过模型实验验证十字换乘车站中采用站厅站台联合通风模式的有效性，并提出多种火源功率、通风模式下的烟气扩散范围和规律，为十字换乘车站的烟气控制模式优化提供了数据支撑。

Model experimental study on fire in metro multi line transfer station:(2) fire in cross transfer station

Aiming at providing a systematic analysis and evaluation of fire scennarios in subway cross interchange stations,with a 1∶10 fire experiment model of the metro multi line transfer station,the fire scenes of the cross transfer station were designed,then the corresponding full scale fire experiments with the heat release rates from 0.91 MW to 2.60 MW were conducted,and the optimized smoke exhaust schemes when the fire occurred in the dangerous positions of station hall and platform in the cross transfer station were studied.The results showed that when the fire occurred at one end of station hall,the smoke exhaust of station hall could ensure that the middle transfer channels and the stairs and exits at the other end of station hall were not affected by the smoke within 6 minutes after fire starts.When the fire occurred at the middle of station hall,the safety of the stairs and exits at both ends of station hall as the evacuation channels could be ensured by using the smoke exhaust of station hall.When the fire occurred in the stairway at one end of underground 2nd floor platform or underground 3rd floor platform,the diffusion range of smoke in the platform could be controlled by using the linkage mode of smoke exhaust in platform and air supply in station hall,which ensured that the stairs without fire in platform and the station hall could be taken as the safe evacuation channels within the first six minutes of fire.Only adopting the smoke exhaust in platform could control the smoke diffusion along the horizontal direction in the platform,but when the heat release rate was larger,the smoke would enter the station hall through the transfer channels and stairs.The effectiveness of the joint ventilation mode of station hall and platform in the cross transfer station was verified through the model experiments,and the ranges and laws of smoke diffusion under multiple heat release rates and ventilation modes were put forward,which provide data support for the optimization of smoke control mode in the cross transfer station.