CFD在曝气沉砂池集气罩通风设计中的应用

Application of CFD in Ventilation Design of Gas-collecting Hood of Aerated Grit Chamber

在现代大型封闭构筑物中,为获得理想和有效的内部空气环境,解决好由机械通风产生的气流形态与构筑物几何边界参数之间的关系十分重要。计算流体动力学(CFD)是解决该问题的一种有效手段。采用标准k-ε双方程湍流模型对曝气沉砂池集气罩内的三维湍气流进行了数值模拟,研究了进风口形式、位置、尺寸以及排风口位置等几何边界参数对速度场的影响。结果表明,排风口位置对罩内速度场的影响不明显,当采用条缝式全周长进风口形式时,罩内工作区的气流形态和均匀性最佳。此外,增加排风量可明显提高集气罩内的流速。

In the interest of designing an efficient and acceptable indoor air environment in big enveloped structures, it is important to resolve the relationship between the geometric boundary parameters and the air flow patterns produced by mechanical ventilation. Computational fluid dynamics （CFD） is an effective tool to settle this problem. Therefore, a numerical simulation on 3-D air turbulent flow in a gascollecting hood of an aerated grit chamber was carried out using standard k - e two-equation turbulence model. The effects of several factors, including shape, location and sizes of intakes, location of vent etc. , on the velocity fields were investigated. The results show that the location of vent has little effect on the velocity field, and desirable air flow pattern is achieved in the case of air inflowing through full fourside slot intake. Furthermore, strengthening ventilation can improve velocity in gas-collecting hood.