基于离散元法的种子玉米剥皮过程籽粒损失分析与试验

Analysis and Experiment on Kernel Loss of Seed Corn during Peeling Based on DEM

种子玉米在剥皮过程中存在大量的籽粒破碎、脱落等损失问题,严重影响种子玉米的单产与经济效益。因此,本研究采用理论分析、离散元仿真与正交试验相结合的方法,探究种子玉米果穗与剥皮机构的互作机理,确定剥皮机构的最优工作参数组合以优化种子玉米剥皮过程。首先,对种子玉米果穗在剥皮机构中的受力及运动进行了理论分析,探究了在剥皮过程中剥皮机构-种子玉米的相互作用关系,并确定了影响剥皮性能的主要因素。其次,基于DEM建立种子玉米果穗-剥皮机构相互作用仿真模型,通过对玉米果穗籽粒损伤及脱落分析,确定了剥皮辊转速、剥皮辊倾角和摆杆摆幅的较优工作范围。最后,根据Box-Behnken设计方法,设计了三因素三水平的正交试验,通过方差分析和响应面分析,筛选出种子玉米剥皮机构的最佳工作参数组合:剥皮辊转速为300 r/min,剥皮辊倾角为10°,摆杆摆动幅度为5°,此时苞叶剥离率为94.13%,籽粒脱落率为1.564%,籽粒破碎率为1.292%。试验获得的剥皮装置的最优工作参数组合,明显提高了种子玉米的剥皮效果。

Seed corn has much seed crushing and shedding losses during the peeling process,which seriously affects seed corn’s yield and economic efficiency.Therefore,a combination of theoretical analysis,discrete element simulation,and orthogonal tests was used to investigate the interaction between the seed corn ears and the peeling mechanism.The optimal combination of peeling parameters was determined to optimize the peeling process of seed corn.Firstly,a theoretical analysis of the force and motion of the seed corn ear in the peeling mechanism was conducted to investigate the peeling mechanism-seed corn interaction during the peeling process and identify the main factors affecting the peeling performance.Secondly,a simulation model of seed corn ear-peeling mechanism interaction was established based on DEM.The better working range of peeling roller speed,peeling roller inclination angle,and pendulum swing were determined by analyzing the seed damage and shedding.Finally,according to the Box-Behnken design method,a three-factor,three-level orthogonal test was designed.The best combination of operating parameters for the seed corn peeling mechanism was screened by ANOVA and response surface analysis as follows:peeling roller speed of 300 r/min,peeling roller inclination angle of 10°,and pendulum swing amplitude of 5°,at which the bract stripping rate was 94.13%,the grain falling rate was 1.564%,and the grain crushing rate was 1.292%.The optimal combination of operating parameters of the peeling mechanism obtained from the experiment significantly improved the peeling effect of seed corn.The research results can provide a reference for the optimal design of the seed corn peeling mechanism to enhance the peeling efficiency of seed corn and reduce the grain crushing rate and the grain falling rate during the peeling operation.