基于CFD-DPM的大规模颗粒-流体系统数值仿真与分析

大规模复杂颗粒-流体系统主要运行参数与多物理场形态的关联机制不清晰,试验研究方法难以对这些运行参数和质量特性之间的耦合关系进行精准描述。为了探究大型立磨运行过程中多物理场耦合工作机理,通过构建粗粒非解析CFD-DPM耦合模型进行数值模拟,分析主要运行参数对立磨流场、颗粒分级、粒度分布以及成品质量的影响,模拟结果与实际工况运行结果吻合度较好,验证了所建数值计算模型能够有效地模拟出大规模颗粒-流体系统的动态选粉过程。结果表明,系统风量与选粉机转速直接影响着立磨离心分级的切割粒径与成品细度,当其它参数不变,随着系统风量增大切割粒径值变大、成品比表面积越小;当只改变选粉装置转速,切割粒径随着转速增大而减小、成品比表面积越大。

Numerical Simulation and Analysis of Large-scale Particle Fluid System Based on CFD-DPM Method

The correlation mechanism between the main operating parameters of large-scale complex particle fluid system and the morphology of multiple physical fields is not clear, and the experimental research methods are difficult to accurately describe the coupling relationship between these parameters and mass characteristics. In order to explore the working mechanism of multi-physics coupling during the operation of vertical mills, numerical calculation is carried out by establishing a coarse-grained non-analytical CFD-DPM coupling model, and the effects of operating parameters on the vertical mill flow field, particle classification, particle size distribution and the finished product is analyzed. The simulation results are in good agreement with the actual operating results. It is verified that the numerical calculation model can effectively simulate the dynamic powder separation process of large-scale particle-fluid system. The results show that the air volume of the system and the rotating speed of the powder separator directly affect the cutoff diameter of the vertical mill centrifugal classification and the fineness of the finished product. When other parameters remain unchanged, the cutoff diameter increases and the specific surface area of the finished product decreases with the increase of the system air volume. When only changing the rotating speed, the cutting particle size decreases and the specific surface area increases with the increase of rotating speed.