Study On Smoke Spread Time Of Subway Car Fire In Tunnel Base On FDS

Subway is an important traffic tool.The structure of the subway tunnel space is particularity.When the fire happens in subway tunnel,the smoke will gather quickly.It will break the rescue conditions,besides it will prolong the survival time,in other words,it could increase the difficulty of evacuation.It will cause significant economic losses and casualties.So the research of spread time that the subway tunnel fire smoke has a great significance for urban disaster prevention and mitigation.The model of shield tunnel,the subway B type,the evacuation passageway,and the source can be eatablish the Fire Dynamics simulation software.It sets up the test points in Beijing metro line B carriages of shield tunnel in the appropriate location.Then proceeding the fire scenario simulation.It obtains the simulation results of detection time for the smoke concentration and alarm time for the smoke visibility.Besides,it also gets the concentration of the flue gas diffusion stability of each case after maximum range,and the gas concentration changing with the time and location.Comparing the simulation results with experimental results,to obtain the time range that detector first detected smoke.It can be found that smoke visibility relative concentration of flue gas alarm lag at the same time.With the auxiliary calculation by fire model visualization software Smokeview,the dispersion of smoke in the escape route in the subway tunnel is simulated by 3D for each case.Comparing the simulation results with experimental results,to obtain the diffusion law of smoke with time.The display section of the visibility of the model in different height positions was established.It can be found that the difference of visibility is different in different height,to provide theoretical basis for the arrangement of the detectors in the tunnel in the future.Taking the shield tunnel in Beijing subway line seven as the experimental object.The data provided by the subway tunnel smoke detection and the hot smoke reduction experiment of the subway tunnel during the internship in Chinese Academy of Building Science.It obtains the relevant information of the support and simulation.Then it refer to the field experiment and provide reference for the final conclusion.