地下商场内火灾烟气运动及控制的大涡模拟

采用湍流大涡模拟方法,对接近于方形的地下商场内的火灾烟气运动及机械排烟进行了数值模拟;研究了机械排烟口的布置和排烟量对火灾烟气排放有效性的影响.结果表明在商场具有防烟分区和挡烟垂壁的条件下,在右侧墙处实施机械排烟比在顶棚处实施机械排烟可取得较好的排烟效果.随着机械排烟量的增大,室内烟气层的高度有明显的上升,从疏散口和自然补风口处流出的烟气速度减小,流入的空气速度增大.

Large eddy simulations of fire smoke flow and control in an underground shopping mall

Large eddy simulation was applied to the simulation of the fire smoke flow and mechanical smoke exhaust in an underground shopping mall with almost equal length and width in the floor area.The present study explores the effects of location of the mechanical exhaust vents and mechanical exhaust rate on the effectiveness of smoke extraction.For the underground shopping mall with ceiling partitions restricting smoke flow,the results indicate that the smoke extraction can be better achieved if the mechanical exhaust vents are located at the right-side wall than at the ceiling.The height of smoke layer increases obviously with the mechanical exhaust rates.As a result,the velocity of smoke flowing from the evacuation doors and the natural air supply opening decreases and the velocity of air entrained into the room increases.