Study On Multi-Factor Effect Of Smoke Exhaust In Atrium Based On Taguchi Method

With the development of social economy,the requirements of atrium in structural style,fire safety and other aspects are getting higher and higher,which brings great challenges to architectural design,smoke control design,and also brings greater heat to the research topic of atrium fire protection.In this paper,the basic characteristics of atrium are analyzed,various smoke exhaust modes are introduced,and the research status of smoke exhaust in atrium is summarized.It is pointed out that there are many factors that affect the smoke exhaust performance of different smoke exhaust systems in atrium,and Taguchi method is a common and effective method to study the multi-factor influence test results.The multi factors are divided into controllable and uncontrollable types by Taguchi test method for orthogonal design,which is conducive to FDS numerical simulation and S/N was used to analyze the influence of multiple factors under different smoke exhaust modes of atrium.The influencing factors in this study include: Controllable factor the shape factor,the roof shape,the layout of the natural smoke vent,the mode and uncontrollable factor location of air supplement,the outdoor wind speed and direction,and the ambient temperature in the natural smoke exhaust system of the atrium;Controllable factor the shape factor,the air supply position,the air supply mode,the design smoke exhaust volume,uncontrollable factor the power of the fire source,the fire area and the position in the mechanical smoke exhaust system;Controllable factor The length-width ratio,air supplement mode,ratio of natural smoke outlet and mechanical smoke outlet,uncontrollable factor power of fire source,outdoor wind speed and direction in the mixed smoke exhaust system.This study mainly analyzes the smoke exhaust effect of the smoke exhaust system by analyzing the three indexes of smoke exhaust volume,ceiling temperature and smoke concentration,and judges the feasibility of the smoke exhaust method and the optimal smoke exhaust scheme by comprehensively considering the three indexes.The main findings are as follows:Natural smoke exhaust was set in the atrium,and each single factor had similar effects on smoke exhaust volume and smoke concentration,but slightly different effects on ceiling temperature.Considering the influence of multiple factors and the interaction among them,it is suggested that the height of the atrium should not be designed to be about 10 m too high,and the smoke vents should be distributed around the flat roof,and the air supply should be in the opposite direction.Mechanical smoke exhaust is set in the atrium,because the smoke exhaust quantity is not affected by the influence factors,the influence of each factor on the ceiling temperature and smoke concentration is quite different.The influences and interactions of each factor are summarized and analyzed.It is suggested that the high and middle school courts with a height of 18 m or above should adopt mechanical smoke exhaust and natural air supply in the same direction.The non-square atrium design has a larger smoke exhaust capacity,while the square design has a smaller smoke exhaust capacity.Mixed-smoke exhaust was set in the atrium,and all the influencing factors could affect both mechanical smoke exhaust and natural smoke exhaust,and the influence of each factor on the three indexes was almost the same.The comprehensive analysis shows that mixed smoke exhaust should be carefully used in atrium buildings.Proportion of natural smoke vent >1/2 of the mixed smoke exhaust can be set in non-square atrium,and it needs to cooperate with natural air supply,while the mixed smoke exhaust should not be set in square atrium.