基于离散元/有限元耦合的高压辊磨粉碎仿真方法与实验研究

High pressure grinding rolls (HPGRs) have the advantages of high adaptability, high efficiency and low energy consumption. So, HPGRs are getting increasing application in the field of mine and metallurgy. However, engineers have been facing the challenges of the design of HPGRs and the selection of the working parameters. The project is proposed based on our long-term research of the fracture characteristics of brittle materials and the combined discrete/finite method. In this project, the ore will be simulated by discrete element method (DEM), while the dynamic and static rollers will be analyzed by finite element method (FEM). In order to analyze the fracture of the ore, a fracture model of DEM for ore material and a contact combining model between granular DEM and FEM will be presented. Furthermore, we will also put forward methods to deal with the difference of the time steps between DEM domain and FEM domain. Afterward, we will validate these models and methods by conducting the fracture experiments respectively. Based on these achievements, we will develop a combined DEM/FEM high-performance parallel program for manycore GPUs and further validate the models and the program by the experiments of particle bed comminution. The comminution process of HPGR will be simulated by applying the program. By analyzing the process, we can study the comminution mechanism of the ore and the effect of the working parameters on comminution characteristics of the ore. This will provide scientific foundations for the design of HPGRs and the selection of the working parameters.

高压辊磨机适应能力强、能耗低、粉碎效率高, 在矿山、冶金等工业领域的应用越来越广。然而，高压辊磨的设计及粉碎作业时工作参数的选取一直是困扰工程界的难题。本项目基于我们长期对脆性材料破坏特性、离散元/有限元耦合方法的研究成果，拟采用离散元法模拟矿石材料，建立描述矿石材料粉碎的离散元模型，采用有限元法分析动、静辊轮的工作状况，发展散体材料破碎的离散元/有限元接触耦合模型，实现离散元/有限元模拟的时间多尺度耦合，并通过破碎实验验证各模型的正确性。基于以上成果，研发基于多核GPU并行算法的高性能离散元/有限元耦合分析软件，并通过料层粉碎实验进一步验证模型和软件的正确性。采用该软件仿真分析矿石高压辊磨粉碎过程，研究矿石粉碎机理及工作参数对粉碎特性的影响，为解决高压辊磨机设计和工作参数选取问题提供科学依据。

本项目旨在研究矿石破碎特性及高压辊磨工作参数对粉碎特性的影响。为实现该目的，提出了适用于处理矿石-高压辊磨机辊轮相互作用的高效率、高精度的离散元/有限元接触耦合算法，并采用面向对象思想，利用FORTRAN2003最新特性，在自主开发的程序CDFP的基础上编程实现了该离散元/有限元接触耦合算法，并通过经典算例验证了其有效性与正确性。并采用正方体规则排列离散元模型研究了矿石材料的破坏特性；模拟了矿石高压辊磨的破碎过程，采用正交实验的方法研究了辊轮转速、辊轮间隙及辊轮与矿石-辊轮间的静摩擦因数等对矿石粉碎效果及生产效率影响的显著性，发现矿石-辊轮间的静摩擦因数对破碎效果和生产效率影响较小。随后研究了辊轮转速、辊轮间隙等对矿石破碎效果和生产效率的影响规律，发现生产效率先随转速增大而增大，当转速达到一定值时，生产效率趋于稳定；破碎百分比随辊轮间隙增大而减小，生产效率随辊轮间隙增大而增大。此外，采用固有型内聚力方法模拟脆性材料动态破坏特性，并研究了矿石材料的流动性及混合均匀性。..到目前为止，共公开发表论文14篇，其中TOP期刊论文1篇，中科院2区期刊论文2篇（不含TOP期刊论文），EI检索期刊论文2篇（不含SCI检索论文），EI检索会议论文2篇，投稿中SCI期刊检索论文1篇，拟投稿SCI期刊检索论文1篇。此外，申请发明专利1项，目前处于待公告状态。