Numerical simulation of the influences of smoke extraction on evacuation

Due to the hazard of the smoke in a building fire,numerical simulations of the smoke movements in three different ventilation working conditions,which include no extraction,natural smoke extraction and mechanical smoke extraction,are achieved by using the commercial computational fluid software PHOENICS.In a fire,both natural smoke extraction system and mechanical smoke extraction system can expel lots of the smoke and the heat from the room,which reduces the concentration of the smoke,the temperature and the pressure.The mechanical smoke extraction system can produce trace negative pressure,which makes smoke diffusion outside difficult,which has good effect on smoke extraction obviously and adds nearly 30 s for evacuation.The results of the study prove the feasibility of field simulation based on the CFD technology during a fire,and confirm the mechanisms of the smoke movements of the fire process in a separate room.It has important theory value and reality significance to fire control and evacuation during a fire.