高层建筑火灾中烟气组合控制设置参数的研究

利用FDS模拟研究走廊中排烟口数量、位置以及挡烟垂壁与缓冲区的结合对高层建筑烟气控制效果的影响,寻找最佳组合烟气控制模式。结果表明,在走廊中部设置1个以排除火灾产生烟气为主的排烟口,在空气幕前方2m处设置1个以排除新鲜空气为主的排气口,并且在排气口后方0.5m处设置1个挡烟垂壁的组合烟气控制模式具有最佳的烟气控制效果。挡烟垂壁离机械排烟口0.5m时,可以有效降低缓冲区及前室的温度和烟气浓度,前室内CO2体积分数下降21.4%,温度下降9℃。当挡烟垂壁离空气幕较近时,走廊内的温度和烟气浓度反而上升。

Study of high-rise building fire composite parameters fire-smoke control models

The purpose of this article is to find and work out an optimal integrated smoke control model for highrise fire.For this purpose,we have developed in this paper a FDS simulation model highly efficient for analyzing the smoke control effect with different mechanical smoke exhaust parameters,location and smoke-hindering-wall and buffer combined control model.Comparing several models of smoke temperature and the concentration of CO2 distribution in the corridor,we can find that the model can set the smoke exhaust in the middle of the corridor mainly purposed to eliminate the smoke from the fire and in front of vertical air jet 2 meters mainly setting the air exhaust for eliminating the air from the vertical air jet and a hang wall 0.5 meters backside the air exhaust has the best smoke control effect.The smoke-preventing-wall of 0.5 m from the air exhaust can make the concentration of CO2 21.4% and the temperature 9 ℃ lower in the buffer,but if the smoke-preventing-wall near the vertical air jet,the concentration of CO2 and the temperature in corridor would go up.The smoke-reducing effect with two mechanical smoke exhausts prove to be better than the mere one.However,the mechanical smoke exhaust is used mainly to eliminate the hot smoke in the middle of the corridor while the mechanical air exhaust is preferably made near the vertical air jet.The smoke-preventing-wall between the mechanical air exhaust and the vertical air jet can help to prevent the smoke diffusion well when it is closer to the mechanical air exhaust. But when the wall is closer to the air jet,there would accumulate a huge mass of smoke near the air jet.Since the hot smoke mixed with the cold air may lead to the acceleration of the smoke sedimentation,it is likely that the temperature and the concentration of CO2 in the end of the corridor would go up,with the mechanical exhaust efficiency reduced and therefore helpless for the safety evacuation.