Research On Fire Simulation And Personnel Evacuation Time In Subway Station

Fire accidents are the most frequent and most catastrophic in subway safety accidents.And because the subway station is mostly underground,it has the characteristics of closed space,complicated structure,dense personnel and few exports.Once a fire breaks out,the smoke rapidly spreads and accumulates in the subway station,forming thick smoke and hot steam waves,and generating a lot of poison.Gas,personnel evacuation is difficult,and it is easy to cause group death and group injury.Therefore,it is of great practical significance to study the fire characteristics of subway stations and the evacuation of personnel.This paper takes a subway station as the research object,and combines the PyroSim fire simulation with the Pathfinder evacuation simulation to study the fire and personnel evacuation time of the subway station.The main work and achievements are as follows:(1)Through the analysis of the characteristics,dangers and safety factors of subway station fires,the main risk factors and danger thresholds in subway station fires are determined,which lays a foundation for the study of fire characteristics and personnel evacuation of subway stations.(2)The pyroSim subway station fire model was established by combining the thermodynamic properties of polyurethane and PVC materials,and the available safe evacuation time(ASET)of each dangerous location in each working condition was analyzed.When the fire source is located in the middle of the platform,the flue gas spreads to both sides of the stairway and spreads vertically upwards to the station floor.The speed is faster,and the dangerous positions reach the dangerous threshold earlier.The safe evacuation time can be used is less.(3)The PVC fire compared with the polyurethane fire in the subway station,the smoke temperature,CO concentration and visibility at the dangerous locations reach the dangerous threshold earlier,and the safe evacuation time available is less.For CO concentration < Visibility < Flue gas temperature,the available safe evacuation time is determined by the CO concentration,while CO is poisonous and the fire hazard is high.(4)The PyroSim fire simulation is fully integrated with the safe evacuation of Pathfinder personnel through the available safe evacuation time settings.Based on the questionnaire and the basic parameters and behavioral characteristics data obtained from field observations,the Pathfinder evacuation model was established for personnel safety evacuation analysis.When the fire source burning material is PVC,the safe evacuation time is less,the fire is harmful,and the personnel fail to complete the evacuation.The location of the fire source is located on the left side of the platform and compared with the middle of the platform.Although there are more safe evacuation times,based on the personnel's panic and behavioral characteristics of the smoke reaction,after a certain period of fire,the personnel will not The passage of the stairway group I from the fire source side is selected,resulting in low utilization of the stair group I and prolonging the evacuation time.Therefore,when the combustible material is PVC,there are many people staying in the working condition on the left side of the platform layer.