Study On Smoke Migration Regularity And Personnel Evacuation In Side Platform Subway Station

In recent years,in the rapid development and construction of the city,subway has gradually become the main means of transportation of the city with its advantages of high speed,low energy consumption and large carrying capacity.The subway station is a large underground closed space,and once a fire occurs in the subway station,the smoke quickly spreads in the station,affecting the evacuation of personnel and posing a threat to personal safety.In the case of a fire on the platform floor of a subway station,people need to be evacuated from the platform floor to the hall floor,and smoke from the chimney effect will spread to the hall floor through the stairwell,thus affecting the safety of people.When the platform floor is on fire,it is very important to ensure the relative safety of the stairway.At the same time,the smoke should be discharged as soon as possible to prevent the smoke from accumulating too much in the station and affecting personal safety.Therefore,it is of great significance to study the law of smoke spreading in subway stations and the evacuation of people.This paper takes jinxiudadao station of Hefei metro line 5 as the research object,which is a typical side platform subway station.The pyrosim software is used to simulate the subway station fire,the temperature,visibility and CO concentration distribution of smoke under the conditions of different falling height of draft curtain,opening and closing simulation of PSD and mechanical smoke exhaust are studied respectively,sum up the influence of these factors on the law of smoke spread,and determine the dangerous time of the stairwell in the subway station.According to the structure and personnel characteristics of the subway station,the safe evacuation time based on fire is calculated by using Pathfinder software.The evacuation time is compared with the personnel are threatened time to determine whether the subway station meets the evacuation requirements.The conclusions are as follows:(1)When considering the falling height of draft curtain,under the condition of natural ventilation,the PSD is closed.The higher the height of the vertical wall,the greater the resistance to horizontal diffusion and the better the smoke control effect.However,the smoke is mainly controlled in the platform layer,which increases the temperature and CO concentration of the platform layer and reduces the visibility.However,the draft curtain of H=1.0m can extend the danger arrival time of the right stairway 42 s.Adding mechanical smoke exhaust on the draft curtain of H=1.0m can not only effectively reduce the temperature and CO concentration of the platform floor,improve the visibility of the platform floor,but also increase the dangerous arrival time of the 12 s right stairway.(2)When considering the opening mode of the PSD,under the condition of natural ventilation,there is no draft curtain.Opening the PSD is conducive to reducing the temperature and CO concentration of the platform floor,and can improve the visibility of the platform floor,the more the number of PSD open,the better the effect.When the PSD is fully open,it can increase the danger of the right staircase arrival time 58 s.Opening the mechanical smoke exhaust on the basis of opening all PSD,that can not only control the temperature and CO concentration of platform layer more effectively,improve the visibility of platform layer,and also extend the dangerous come time of 6s right stairs.(3)When the draft curtain,the mechanical smoke exhaust and the PSD act together,the control effect on the temperature and CO concentration of the platform layer and the visibility of the platform layer are the best,while the risk of the right stairwell is the latest.(4)All people in the station can be evacuated to a safe area at 211.5s.The evacuation time of people on the platform floor is 187 s,which is less than 214 s,indicating that the station can be evacuated safely.The focus of this paper is the simulation of subway station fire and safe evacuation of personnel.The research of this paper is of great significance for the control of subway station fire,the reduction of loss,the guarantee of life safety of personnel and the safe operation of subway.It is hoped that it can provide some ideas for the fire protection design and management of subway side stations in the future.Figure [45]table [9] reference [63]...