Research On Law Of Smoke Movement And Evacuation Of Subway Station Under Different Fire Positions

In the method to alleviate the traffic pressure in the city,subway has been developing rapidly in our country as the most effective method,but during the subway operation process,fire has become an important problem become more and more prominent in the prevention of subway fire and emergency treatment.The subway station’s inner space is relatively closed,exiting with fire smoke is not easy.Concentrated heat,cooling slowly,air temperature rises fast and other characteristics,once the sound of fire,the crew escape,personnel evacuation and fire control is very difficult,involving a large range,and will cause serious casualties and economic losses.The structure of metro station is complex,entrances,crowded,and the complex traffic relations affects people ’ s behavior,defines or guides the occurrence of behavior.This study takes a typical subway station as research object,summarizes the reasons,characteristics and research status of the subway fire based on a large number of literature review.After comprehensive comparison of various research methods,the numerical simulation technology is used to study the characteristics and control of smoke propagation in subway platform fires.Pyrosim software was used to simulate and control the spread and control of smoke in various locations such as the subway train body,subway platform,and station hall.Through the field investigation,data query,and theoretical calculation,the design of the fire scene of the subway and the fire source power and grid were determined.The grid division and other simulation parameters are arranged in different places of the subway station and suitable fire sources are numerically simulated to simulate fires at typical locations within the platform.The fire smoke plume characteristics of the platform fires are analyzed,and the role of smoke prevention devices within the station is analyzed.According to the field investigation and inquiry data,the evacuation exit and entrance arrangement and personnel load of the evacuation were determined,and a reasonable evacuation route was designed based on the investigation of the characteristics of smoke propagation.The building evacuation characteristics were simulated using Building EXODUS,and the fire safety of the subway station was qualitatively and quantitatively evaluated.Verify the optimization plan.Studies have shown that the main factor influencing ASET is visibility.The water spray system can effectively reduce the temperature of the fire field but has less impact on visibility.The mechanical exhaust can control the visibility reduction time,but it is easy to make the ceiling temperature too high and optimize the machinery at the same time.Ventilation and adding water spray system can increase the ASEAT to 600s;increasing the evacuation exit width has the most obvious effect on reducing the RSET and the optimization rate exceeds 10%.These data will guide the design of smoke control system and guide the evacuation of passengers in the event of an accident.The numerical simulation method of ventilation and fire in subway station and the temperature distribution,smoke distribution and smoke concentration distribution under fire conditions can be used to provide reference for China’s subway construction.