立磨腔内气相流场数值模拟与分析

摘要

Distribution characteristics of the air flow field in the cavity of a vertical mill was numerically simulated and analyzed by using the computational fluid dynamics software. The distribution laws of the air flow field in the mill cavity were found out and local structure of the mill cavity was optimized. The simulation results showed： the air flow field in the mill cavity consisted of circumferential vortex and longitudinal vortex, and came very complicated under the influence of the wind ring, ash hopper and rotary grinding roller; clock- wise forced vortex appeared in separation area, and local secondary vortex existed between some air blades, so it was concluded that the installation angle of the air blades should be changed as per their locations. The paper studied the influence of air cone of air loop on the flow field in the mill cavity, which offered methods and refer- ences for structural optimization and further study of the mill.%利用计算流体力学软件对立磨腔内气相流场的分布特性进行数值模拟分析，摸清腔内流场的分布规律，并对腔内局部结构进行优化设计。模拟结果表明：立磨腔内的流场主要由周向涡流和纵向涡流耦合而成，并在风环、灰斗和旋转磨辊的影响下变得十分复杂；在选粉区域呈现出沿顺时针旋转的强制涡流，且在部分导风叶片间产生局部二次涡流，认为导风叶片的安装角度应随位置的不同而有所改变。就风环结构中的导风锥对立磨腔内流场的影响做了深入研究，为立磨的结构优化设计和进一步研究提供了方法和依据。