The Influence Of Different Train Speeds On The Spread Of Fire Smoke On The Platform Floor Of Side-island Mixed Subway

With the development of subway,the platform forms tend to be diversified and complicated,among which the side Island mixed platform has complex structure and huge passenger flow.Once a fire occurs on this platform,it will pose a major threat to the safety of passing trains and platform passengers.It is one of the measures to ensure the safety of train passengers that the train oversteps the station,but it may increase the uncertainty of fire smoke spread and the difficulty of evacuation.Therefore,it is of great significance to study the influence of train Cross Station on the fire smoke spread of side island platform.In order to explore the influence of the stoppage air produced by the train passing through the station on the smoke spread of the platform fire,fluent and pyrosim are used to simulate the smoke spread of the piston air produced by the train passing through the station on the side Island mixed platform fire.Through the analysis of CO volume fraction,visibility and temperature,the paper analyzes the length of time that the fire smoke spread makes the platform evacuation stairs lose the ability of safe evacuation,which can reflect the impact of the train crossing the station on the fire smoke spread.The results show that the low visibility first leads to the dangerous situation of all evacuation stairs in a single platform;when the train crosses the station,the impact of two-way train crossing the station is greater than that of up train and down train crossing the station on the platform fire smoke.When there is no train crossing the station,the stairs of the island platform fire will lose the safety evacuation ability 5 minutes and 8 seconds later,and the stairs of the side platform fire will lose the safety evacuation ability 4 minutes and 48.5 seconds later;when the two-way crossing speed is 18.5m/s,the stairs of the island platform fire will lose the safety evacuation ability 4 minutes and 33 seconds later,compared with the island platform fire without train crossing the station,evacuation will lose the safety evacuation ability The time available for safe evacuation is shortened by 8.8%.After the side platform fire happens 4 minutes and 10 seconds,all the stairs lose the ability of safe evacuation.Compared with the island platform fire without train crossing the station,the time that the evacuation stairs can provide for safe evacuation is shortened by 13.3%.Adjusting the vehicle speed and adding smoke damper wall can effectively reduce the fire smoke spread speed.Compared with the case that the vehicle speed is 18.5m/s and smoke damper wall is not added,the safe evacuation time of island platform and side platform can be extended by 8.4%and 9.2%respectively in case of fire.