Study On The Fire Emergency Evacuation Of The Large Gymnasium

As the rapid development of our society and economy,some form of novel and functional large space buildings like gymnasium emerge in endlessly.In case the event of fire in these places may cause the severe consequences of group death and injury because of the spread of the smoke out of control,easy to produce toxic or harmful gases,labor intensive,longer evacuation distance,difficult safe evacuation and out fire and rescue and so on.It has a certain theoretical and practical application value that study persons will be able to evacuate in the large space buildings.This paper aim at the fire of the gymnasium,use the method of numerical simulation and analyze the spread of smoke and the influence factors of evacuation.The main work and conclusion in this paper are as follows:(1)This paper establishes a gymnasium,3D model based on the fire dynamic simulation software FDS.The study found that when central floor occur a fire,because the fire is located in the center of the building,and high temperature flue gas by the buoyancy effect vertical building gas temperature gradient and density gradient generated by the generated ceiling jet phenomenon,because the barrier walls began to generate smoke movement of hot smoke layer formed in the sky along with the development of the fire,the smoke layer became thicker,finally filled the entire space;the fire is located in the stadium seats,due to the fire position asymmetry in buildings,causes that gas flow in large space distance is extended,the temperature and concentration are greatly reduced,so that the flue gas in the distant location over the aggregation layer,along with the development of the fire,the smoke layer became thicker,began to spread to the other side,and the formation of sports in the sky hot smoke layer,and finally filled the entire space(2)It is based on fire and smoke temporal and spatial distribution,it is on the basis of the outlet of smoke layer height and distance from the ground at the height of 2m,CO concentration and visibility risk value to determine the personnel evacuation time(ASET),the fire is located in the central stadium floor,three export ASET are basically the same;the fire is located in the grandstand seats,due to the asymmetry of fire location the distance from the nearest exit 1' s ASET is most,export 3 is more and export 2 is least;affect visibility to ASET is greater than the smoke layer height,temperature and CO concentration;enable mechanical exhaust,ASET is about 350 s.(3)ASET and RSET are the key factors to judge personnel safety evacuation in the fire.It discusses the influence factors of evacuation base on Pathfinder to determine the RSET.When the fire located in the central floor,all persons can evacuate to the safe area before 1068.11s;when the fire located in the grandstand,the person who near the fire evacuate priority.All persons can evacuate to the safe area before 1106.96 s.By comparing the ASET and RSET,while the mechanical smoke exhaust is closed,all sportsmen and the audiences in the gymnasium could not evacuate safely before smoke layer height,temperature,CO concentration and visibility reach the dangerous value;while the mechanical smoke exhaust is started,all sportsmen and the audiences in the gymnasium can evacuate safely before smoke layer height,temperature,CO concentration and visibility reach the dangerous value.