基于离散单元法的螺旋输送装置工作过程数值模拟  

Numerical simulation of working process of screw conveyer based on discrete element method

作　　者：张克平[1,2] 王国华[2] 柴强[1] 

机构地区：[1]甘肃农业大学农学院,甘肃兰州730070 [2]甘肃农业大学工学院,甘肃兰州730070

出　　处：《干旱地区农业研究》2016年第6期285-291,共7页Agricultural Research in the Arid Areas

基　　金：国家科技支撑计划(2012BAD14B10);国家公益性行业计划课题(20110301);国家自然科学基金项目(51265001);甘肃省自然科学基金(1506RJZA021);甘肃农业大学伏羲青年英才培养计划项目(FXYC20130103);甘肃农业大学青年导师基金(GAUQNDS-201405)

摘　　要：为了验证组合螺旋输送装置应用于小型收获机的可行性和研究籽粒在其中的流动规律,本文以散体力学为基础,依据离散单元法(DEM)分析螺旋输送器的输送机理。通过建立输送器三维模型,以豌豆为例分析其在螺旋内的运动,应用可视化离散元模拟软件EDEM分析等螺距、变螺距输送过程中豌豆颗粒接触数目、豌豆速度、豌豆受力及输送能耗等变化情况,初步探讨了颗粒破碎原因,并对输送速度及破碎率进行了试验验证。研究结果显示:相对于等螺距输送,变螺距输送在提高输送速度的同时降低了能耗,且籽粒受力、接触数目较大处主要集中在输送初期,变螺距输送不仅可以通过提高豌豆颗粒输送速度提高输送效率,而且能降低颗粒间及颗粒与叶片间挤压与摩擦,进而改善输送过程中颗粒破碎现象;颗粒受力最大处主要集中在螺旋叶片外径和箱体内壁之间及两输送器的结合处。In order to verify the feasibility of applying combined conveyor device into small harvester and research the flow rule of grain,this paper based on the granular mechanics,according to the discrete element method（DEM） analyzed the conveying mechanism of screw conveyor.Through established the three-dimensional model of conveyor,analyzed its movement in conveyor taken pea as an example,applying the visual discrete element simulated software EDEM analyzed the change situation of pea grain contact numbers,pea velocity,pea pressure and total energy consumption during conveying process by equal and variable pitch of screw,preliminarily discussed the cause of grain broken,and experimental verification has been conducted for the convey speed and broken rate.The results showed that：Relative to the equal pitch transportation,by variable pitch transportation the conveying velocity can be increased,while the energy consumption can be reduced,also the grain pressure and large contact numbers were mainly concentrated in the early conveying period.So the variable pitch transportation was not only increased the conveying efficiency by raising the conveying grain speed,but also reduced the squeeze and friction between particles and grain with blades,and then improved the grains broken phenomenon in conveying process.The maximal grain pressure force position was mainly concentrated between the external diameter of screw blade and case inner wall and the junction of two conveyers.

关 键 词：收获机 螺旋输送器 离散元法 EDEM 破碎率 

分 类 号：S225.6[农业科学—农业机械化工程]