Study On Fire Smoke Spread In A Double-deck Island Subway Station

With the continuous development of urban transport industry,subway has become one of the most common means of transportation,undertaking more and more important passenger transport tasks.However,while subway brings convenience to people,there are also some potential safety hazards: the subway station has a special environment,a large passenger flow and a large number of combustibles.Once a fire occurs,it is easy to cause mass casualties and injuries.The most dangerous to people in fire is the high-temperature smoke produced by combustion,which will lead to anoxia,suffocation,poisoning and other phenomena in the process of evacuation.Therefore,it is of great significance to study the smoke spread law in subway stations and the smoke control and exhaust mode in subway stations.On the basis of on-the-spot data monitoring and data analysis,this paper takes Huangshan Road Station of Hefei Metro Station as the research object,establishes a fire model by using PyroSim software,setting relevant boundary conditions and parameters,and finally analyzing the smoke spread and the distribution of temperature,CO concentration and visibility under various scenarios.The influence of fire location,platform screen door and smoke barrier on smoke spread is studied,and relevant conclusions are drawn.(1)Under the natural smoke exhaust mode,the influence of different fire location on smoke spread was studied,and the most disadvantageous position of fire was determined.The middle waiting area of the central staircase and the right staircase are the most disadvantageous places for the fire.After the fire,the smoke spreads quickly and extensively.The hall floor will be filled with smoke in a very short period of time,and the visibility will rapidly drop below 10 m.The temperature of the central and right staircase portals will exceed 60 degrees Celsius.(2)Under the mechanical smoke exhaust mode,the influence of the screen door on the smoke spread was studied,and it was concluded that the smoke control effect was the best when the screen door on both sides of the platform was completely closed.The smoke control effect of the screen door on one side is the second,and the smoke control effect was the worst when the screen door on both sides of the platform was completely closed.At the same time,the smoke control effect of opening the screen door on the side away from the fire is better than that of opening the screen door on the side near the fire source.(3)In the mechanical smoke exhaust scenario with the shield doors on both sides of the platform completely closed,smoke barriers were added at the stairway entrance to study the influence of smoke barrier on smoke spread.The results show that smoke barrier can effectively inhibit smoke spread and help people to evacuate safely.Finally,according to the results of the study,reasonable suggestions are put forward for the smoke control of subway station fire,hoping to provide reference value for the actual design of subway project smoke control and exhaust.