| Atrium space of public buildings is tall and wide,connected with other spaces in buildings,which can be used as a distribution center for crowds,create landscapes,gather people and increase attraction of buildings.It is a space structure often selected in architectural design.However,because of its interconnectedness with other spaces,atrium is easy to become a smoke gathering place,and once a fire occurs,it will inevitably cause serious consequences.In the past,atrium smoke research was mostly based on atrium with equal cross section.Atrium with stepped cross-section is widely used in public buildings because it can form a good spatial intention on account of its certain sight guidance and space guidance.However,the particularity of its structure also directly affects the radial diffusion of fire smoke,which makes it difficult to evacuate people.Therefore,it is of great significance to study spread characteristics and control methods of fire smoke in stepped atriumBased on stepped atrium,Pyrosim fire simulation software was used to build a model and carry out numerical simulation to monitor the smoke concentration distribution and filling process of fire.The influence of different types,step length,smoke outlet position and fire source position of stepped atrium on the smoke concentration distribution and smoke exhaust effect was analyzed.The results show that stepped atrium is helpful to delay the decline of smoke layer,and the V-type atrium can maintain good smoke exhaust performance before,during and after the fire development;When the ratio of step length to floor height reaches 0.75,the smoke exhaust volume of atrium is the smallest,and smoke temperature of atrium reaches the highest value,which should be avoided in the early stage of architectural design;Different fire source locations have different effects on the spread characteristics of fire smoke in stepped atrium.When the fire source is located in atrium,the smoke develops rapidly,which is the focus of fire prevention and control,especially near the cloister;Different configurations of smoke exhaust outlets have different effects on smoke exhaust effect.The top opening is better than the side wall opening.The closer the top opening is to the fire corridor in the horizontal direction,the better the smoke exhaust effect is.The higher the side wall opening position is,the better the smoke exhaust effect is.When the two are combined for smoke exhaust,the top opening of the combined side wall can enhance the smoke exhaust effect,but the smoke exhaust effect is not obviously improved when the side wall is not open at the top.The research in this paper has good engineering application value,research results can provide a theoretical reference for architectural design and smoke control design of stepped atrium,and lay a theoretical foundation for fire prevention and control of public buildings.The research in this paper has good engineering application value.Research results can provide reference for the architectural design and smoke control design of stepped atrium,and contribute a part of strength to the fire safety research of atrium buildings. |
