Research On Smoke Control Of Subway Station Fire Under Water Spray

As a world-recognized modern large-capacity urban public transport,the subway has effectively solved the problems of urban population congestion,vehicle congestion and other problems due to its advantages of fast,large capacity,energy saving,high efficiency,environmental protection and small occupied area.The promotion of the operation department,the construction of the subway is also used as an important indicator to show the national economy,technological achievements,and urban facilities.At the same time,the subway station,as a subway interchange hub,is an underground building with closed space,limited import and export,and concentrated personnel.In this special case,if a fire occurs,high temperature and smoke will cause extreme psychological panic,which is easy.Leading to mass casualties,and the subway station as the main traffic of the city,is closely related to people’s lives.The damage to the structure of the subway station caused by the fire will cause great economic losses and strong social impact.Therefore,it is of great significance to continuously explore the fire prevention research of subway stations to ensure the safety of urban personnel and maintain social stability.Based on the previous studies,this paper applies the water sprinkler system to the smoke control of subway station fires.Through a large number of data review,field investigation and numerical simulation,the subway fire model is established.The simulation has no water spray effect and different.Under the smoke exhaust mode,the fire smoke diffusion law under different fire source locations of the subway station and the temperature,CO concentration and smoke layer height of the subway station platform and the compartment.The research shows that under the condition of natural smoke exhausting,the temperature near the fire source rises rapidly to 800-1000 °C,which threatens the safety of personnel and the stability of the roof structure of the platform.The smoke in the compartment and the platform space cannot be discharged in time.With the passage of time,the smoke gradually accumulates,the height of the smoke layer drops rapidly to less than 1.8m,and the CO concentration reaches 2000 ppm,which threatens the safety of personnel;after the mechanical ventilation of the exhaust gas velocity of 3m/s is added,under the action of mechanical exhaust The fire smoke is quickly discharged,so that the CO concentration in the fire smoke is less than 2000 ppm,and the smoke layer is stably maintained at a height of 1.8m or more,all within the safety value range of ensuring personnel safety,but the protection of the roof structure of the platform and the fire source The effect of lowering the temperature in the upper position is not obvious;after setting the parameters of the automatic sprinkler system reasonably,the temperature above the fire source drops to a temperature field less than 400 °C under the action of mechanical exhaust,which belongs to the "low temperature effect"."The bearing capacity of the concrete structure of the platform roof will not change,and the temperature of other locations in the entire fire environment will not rise much by the high temperature effect of water vapor." Subject to certain disturbing the smoke layer,but under mechanical ventilation will not threaten the safety of personnel.It can be concluded that the subway station can effectively protect the main structure of the subway station while ensuring the safe evacuation of the subway through the reasonable setting of the automatic sprinkler system and the mechanical smoke evacuation,which is conducive to the construction after the disaster and the rapid recovery of the traffic after the disaster.The research structure of this paper has certain scientificity,and it has strong operability and practicability.It has certain reference function for fire protection design of subway stations.