采用机械排烟是控制建筑火灾烟气扩散与蔓延的一种有效手段。利用大涡模拟方法,对建筑物室内火灾烟气运动及机械排烟进行了数值模拟。在室内后侧墙处有机械排烟口的条件下,模拟得到的烟气瞬时温度随时间的变化与实验相符合,计算出的烟气层高度也与实验相符合。通过数值模拟对室内机械排烟口的位置进行了优化选取,表明机械排烟口的不同位置对室内烟气运动有较大的影响。当火源位于房间地面中心时,在顶棚中心或左端中心实施机械排烟比在后侧墙处实施机械排烟可取得较好的排烟效果。这说明将排烟口布置在沿烟气运动趋势较强的路径且远离进风口处,可有效地控制室内烟气层的高度。 The use of mechanical exhaust smoke is an effective means of controlling the spread and spread of building fire smoke. The large-eddy simulation method was used to simulate the indoor smoke and smoke exhaust in buildings. Under the condition that there are mechanical exhaust vents in the back wall of the room, the simulated flue gas instantaneous temperature changes with time is consistent with the experiment, and the calculated flue gas layer height is also consistent with the experiment. Through the numerical simulation, the location of the mechanical exhaust port in the room is optimized and selected, which shows that different positions of the mechanical exhaust port have a greater impact on indoor smoke movement. When the fire source is located in the center of the floor of the room, it is better to exhaust the mechanical exhaust in the center of the roof or in the left center than to exhaust the mechanical exhaust in the back wall. This shows that the exhaust port is arranged along the path of strong movement along the flue gas and away from the inlet, which can effectively control the height of the indoor flue gas layer.