排烟口设计对排烟效果影响的模拟研究

Simulated model on the effects of the smokeventilator design on the exhaust of the smoke

通过FDS模拟计算,考察烟气稳定性、烟气溢流厚度、烟气溢流量和机械排烟效率等参数研究排烟口高度的变化和排烟速率的变化对排烟效果的影响。研究结果表明:排烟效果随着排烟口位置的升高而逐渐变好,排烟口与蓄烟池下沿的垂直高度在0.8 m以上效果最好;排烟速率宜适中,过大容易导致烟气层紊乱,过小则控制烟气溢流效果不好并且排烟效率不高。

This article is aimed at presenting a simulated model on the smoke exhausting effect at different heights and different exhausting velocities of the vent. As a matter of fact, in practical engineering, smoke ventilator should be designed allowing for the smoke exhaust effect. In current design practice, it doesn＇ t seem very strict with the design parameters of smoke vent, which habit has made the design random in engineering routine. As a result, it fails to be conducive to smoke exhaust efficiency and the designing success. Therefore, it has become an important technical issue how to design the smoke vent rationally and effectively. To solve the problem, we have analyzed all the factors involving the smoke exhausting efficiency, such as the smoke layer stability, the flow of the smoke layer and the efficiency of the mechanical smoke exhaust by doing experiments with the artificial or mechanical smoke exhaust. The results of our experiments show that different configurations of smoke ventilators are likely to lead to different effects of smoke exhausting. All in all, the height of the smoke vent proves to play some meaningful role. That is to say, the efficiency of the smoke exhaust can be improved with the increase of the smoke vent. The vertical distance between the block wall and the smoke vent proves to be 0.8 m above. In addition, the mechanical smoke exhaust velocity should be kept moderate, for too great velocity is likely to lead to the disorder of the smoke layer. On the other hand, if the flow of the smoke layer is too small, the exhaust efficiency would be too low.