散状物料转载系统设计DEM仿真方法的研究

The research on DEM method to design bulk material transfer system

颗粒仿真技术可以对散状物料的运动进行观察、机理分析、受力分析、磨损(寿命)估计和系统优化.比较了散状物料转载计算方法,给出了采用DEM方法的建模与模型检验的基本步骤.针对DEM计算方法存在所需计算时间过长的问题,实验比较了降低剪切模量和增大颗粒粒度等方法对DEM计算时间和实验结果的影响,结果表明,在不影响计算结果的前提下可通过降低剪切模量和增大颗粒粒度来缩短DEM仿真计算时间.利用EDEM软件实现了散料转载过程的可视化,比较分析了直线型溜槽、折线型溜槽和曲线型溜槽中物料转载效果.仿真表明:采用变曲率半径效果更好;U型溜槽截面能够减少物料不对中情况的发生.

Particulate material simulation technology can observe the motion condition of the bulk material, analyze the material＇s motion mechanism and the forces which act on the materials, it also can estimate the wear condition which means the remaining useful life. Besides, it can opti- mize the transfer system. Different calculation methods of bulk material transfer were compared~ the steps of modeling and model checking using Discrete Element Method （DEM） method were built. Due to the problem of excessive computation time required by DEM calculations, the dis- crete element simulation was carried on in the condition of reducing shear modulus and increasing particle size. After comparing the experimental results and computing time of DEM with normal condition, it shows that the methods of reducing shear modulus and increasing particle size can reduce the time of DEM simulation on the premise of having no affection on the result. A simula- tion model established in EDEM software realized the visualization of material flow in transfer process. The effects of the material transfer in the straight line chute, polyline chute and the curved line chute are compared. Simulation results show that variable radius is better for material transfer and ＂U＂ type chute cross-section can reduce the misalignments in transferring the bulk material.