大空间建筑自然排烟烟流逆转现象理论分析

为了研究不同强度逆向自然风对建筑自然排烟系统排烟效果的影响,以某音乐厅为例,理论分析并数值模拟2.5 m/s、10.0 m/s逆向自然风对该建筑自然排烟效果的影响。结果表明:理论分析结果与数值模拟结果相吻合,当自然排烟受2.5 m/s的逆向自然风影响时,烟囱效应产生的热压(8.76 Pa)克服自然风产生的逆向风压(3.00 Pa),烟气可以通过排烟窗排至室外。但当自然排烟受10 m/s的逆向自然风影响时,烟囱效应产生的热压(8.76 Pa)不足以克服自然风产生的逆向风压(48.00 Pa),烟气在逆向风的作用下出现烟流逆转。因此,大空间建筑采用自然排烟方式时应考虑烟流逆转现象,排烟窗应尽量避免迎主导风向侧布置。

Theoretical Analysis of Smoke Reverse in Natural Smoke Ventilation System in Large Space Buildings

In order to investigate the effect of reverse air flow on the natural smoke exhaust system,the influence of 2.5 m/s and 10.0 m/s upwind on the natural ventilation in one odeum was theoretically analyzed and numerically simulated.The research shows that 2.5 m/s upwind would generate 3.00 Pa reverse wind pressure lower than the 8.76 Pa hot pressure,so the smoke could be exhausted from the large space building.But 10 m/s upwind air would generate 48.00 Pa reverse wind pressure higher than the hot pressure that would cause smoke reverse in the large space building.So in the engineering application,when the natural smoke ventilation system is applied in the large space building,the natural smoke exhaust windows should not be placed on the windward side.