Numerical Simulation Of Plume Flame In Concave Tall Buildings Under Fire Environment

Tall buildings are one of the most widely used forms of architecture in cities at home and abroad,and concave tall buildings are a typical architectural form.The concave tall building has side walls on both sides.When a fire occurs,due to the chimney effect,the flame spreads extremely fast,causing great harm to life and property.Therefore,it is especially important to study the fusion height and variation law of multi-window plume flame in concave tall buildings in fire environment.In this paper,PyroSim software is used to numerically simulate the fire building model under the influence of different side wall length,fire load density,position and number of fire source windows,and draw window temperature time history curve and longitudinal temperature distribution isotherm according to the simulation results.And introduce the dangerous temperature T(the judgment temperature of the plume flame height),T1(the ignition temperature of the polystyrene foam of the building exterior insulation material)and T2(the fire endurance temperature of the glass fracture),and analyze the height of the flame fusion at the dangerous temperature.The law of change with various influencing factors.According to the simulation calculation,the fusion phenomenon occurs in the horizontal and vertical adjacent multi-window plume flames.When the fire source window is located in the inner wall of the groove,considering the dangerous temperature T1 and T2 where the external fire spread of the tall building plays a leading role,the height of the flame fusion of the longitudinally adjacent two windows is 2.25m-5.9m higher than that of the single window,and the longitudinal phase The height of the adjacent three-window flame fusion is 0.65m?2.80m higher than that of the longitudinally adjacent two windows,and the height of the longitudinal adjacent four-window flame fusion is 0.01m?0.13m higher than that of the longitudinally adjacent three windows,and the longitudinally adjacent five-window flame is fused.The height is increased by 0.06m-0.20m than the longitudinally adjacent four windows,and the height of the longitudinally adjacent six-window flame fusion is increased by 0.11m?0.39m compared with the longitudinal adjacent five-window.When the fire source window is located on the side wall of the groove,the plume flame fusion height of the single window,the laterally opposite two windows and the longitudinally adjacent two windows is increased by 0.4m?1.0m,the horizontal and vertical four windows,the longitudinally adjacent three windows and the horizontal and vertical The flame fusion height corresponding to the six window dangerous temperature is increased by 2.5?7.7m.The results show that when the fire source window is located in the inner wall of the groove,the height of the flame adjacent to the four adjacent windows,five windows,six windows and the longitudinally adjacent three windows is basically the same at different fire load densities,the highest is 12.96m.Therefore,when considering the prevention and control of the fire spread outside the concave tall building,the height of the fire-resistant barrier zone should be set to 13m,which can effectively prevent the external fire from spreading upward.When the fire source window is located on the side wall of the groove,the plume flames of the single window,the laterally opposite two windows and the longitudinally adjacent two windows are not affected by the corresponding chimney,resulting in the plume flame not fully fused,the number of these kinds of windows The height of the dangerous temperature does not substantially change significantly.The horizontal and vertical four windows,the longitudinally adjacent three windows,and the plume flames of the horizontal and vertical six windows are fused together,so that the flame fusion height corresponding to the dangerous temperature is greatly increased.Fire doors and windows should be installed in the same type of tall building to delay the internal spread of the fire and control the generation of horizontal and vertical multi-window plume flames.