Numerical Simulation Study Of Mechanical Smoke Exhaust In Atrium Of Commercial Buildings

Building fire is the most common disaster threatening public safety.It has the characteristics of strong sudden,rapid spread and difficult to put out.It is easy to cause economic losses and even casualties.Atrium buildings form a form of integration and isolation with the external space,which has been widely recognized by people.However,atrium buildings are easy to pose a more serious threat in case of fire compared with ordinary buildings because of their special spatial structure.Therefore,this paper is of great significance for the research of mechanical smoke exhaust system in atrium of commercial buildings.Based on the smoke exhaust requirements of the current domestic specifications for the smoke control system and the research status of smoke exhaust control of atrium buildings at home and abroad,this paper makes a series of analysis and Research on the smoke exhaust effect of the horizontal smoke exhaust outlet on the atrium roof and the lateral smoke exhaust outlet on the side wall of the atrium of commercial buildings from the influencing factors such as different fire source power,different length width ratio of the smoke exhaust outlet and smoke exhaust speed of the smoke exhaust outlet through the fire numerical simulation software FDS,The main research contents and results of this paper are as follows:(1)The width of the smoke exhaust outlet of the atrium is always lower than the critical smoke exhaust level of the fire source,and the smoke exhaust outlet of the side of the atrium is always lower than that of the fire source.(2)Under different fire source power and different length width ratio of smoke exhaust outlet,the smoke exhaust efficiency of horizontal smoke exhaust outlet on atrium roof and lateral smoke exhaust outlet on atrium side wall gradually decreases and tends to be flat with the increase of smoke exhaust speed.When the ambient wind is not considered,the smoke exhaust efficiency of lateral smoke exhaust outlet is always higher than that of horizontal smoke exhaust outlet.(3)It is found that the critical smoke exhaust speed of the horizontal smoke exhaust outlet on the atrium roof and the lateral smoke exhaust outlet on the side wall of the atrium is the highest when the length width ratio of the smoke exhaust outlet is 1:1.The power of fire source is 1MW,and the size of smoke outlet is 1m × At 1m,the critical smoke exhaust speed of the horizontal smoke exhaust outlet on the roof of the atrium is 10 m / s,and the critical smoke exhaust speed of the lateral smoke exhaust outlet on the side wall of the atrium is 12 m / S;The power of fire source is 4MW,and the size of smoke exhaust outlet is 1m × At 1m,the critical smoke exhaust speed of the horizontal smoke exhaust outlet on the roof of the atrium is 12 m /s,and the critical smoke exhaust speed of the lateral smoke exhaust outlet on the side wall of the atrium is 14 m / s.Compared with other smoke outlets with length width ratio,1:1 smoke outlet is less prone to plug holes,which is more conducive to smoke exhaust.