Study On Numerical Simulation Of Workshop Fire And Safe Evacuation Of Occupant

With the development of national industrialization and the improvement of economic level,tens of thousands of manufacturing enterprises have been formed,resulting in more and more occupant-intensive industries.While these industries bring people material and living convenience,they also produce many potential safety hazards.If a fire accident occurs,it will threaten the life safety of occupant and pollute the environment.By analyzing the current situation of fire and evacuation research at home and abroad,the research purpose,research method and technical route of this paper are put forward.Firstly,this paper analyzes the building characteristics and development trend of the workshop,theoretically analyzes the building development trend and layout characteristics of the workshop,lists the fire accidents in recent years,analyzes the causes of the fire accidents,and summarizes the problems faced by the safe evacuation of occupant.The Pyrosim simulation software was used to model the fire scene,and the changes of outlet temperature,visibility and CO concentration under different working conditions were obtained.the temperature of each outlet under the four working conditions did not reach the dangerous value,and the highest temperature of each outlet under mechanical smoke exhaust was relatively low.The visibility and CO concentration at the outlet 3 under the first-floor natural smoke exhaust reach the limit earlier,while the parameters at the outlet 2 reach the limit earlier under the mechanical smoke exhaust.The visibility at the outlet under the two-floor smoke exhaust modes is earlier than 10 m.The comparison shows that visibility has the greatest impact on occupant evacuation,and the available safe evacuation time under various working conditions is obtained.Through the use of Pathfinder software to simulate the evacuation of occupant,the evacuation situations under two scenarios are simulated,and the necessary safe evacuation time(REST)of occupant is obtained.From the simulation results,it can be seen that most of the staff are concentrated in the middle of the workshop.In scenario 1,when the occupant begin to evacuate,the occupant of each layer will choose the exit closest to themselves.Since exit 2 is in the middle position,most of the occupant choose to escape from this exit.However,there are fewer evacuees at other exits.After the evacuation at other exits is completed,there are still people in the vicinity of the exit,which takes a long time to evacuate as a whole.As a result,people cannot be evacuated safely.In scenario 2,because exit 2 could not be used normally,the central staff of the workshop chose exit 1 close to themselves,which led to a large number of occupant at exit 1 and the occupant could not be evacuated safely.by dividing the staff of each floor into areas for evacuation,the number of occupant passing through a single exit was reduced,and the number of evacuees at other exits with low utilization rate was increased,thus improving the overall evacuation efficiency and reducing the evacuation time.at the same time,some suggestions were put forward on occupant safety training and evacuation plans.