基于EDEM的离心甩盘撒肥器性能分析与试验

Performance analysis and experiment on fertilizer spreader with centrifugal swing disk based on EDEM

为提高颗粒肥料撒施均匀性,该文对离心甩盘式撒肥器进行甩盘转速、喂入量、喂入角和喂入位置角对抛撒均匀性单因素离散元仿真分析,完成多元回归正交旋转仿真试验和目标参数优化并进行台架试验,分析结果表明,喂入位置角与转速及喂入位置角与喂入角间交互作用对撒肥均匀性影响均高度显著;各因素影响主次顺序为甩盘转速、喂入角、喂入量、喂入位置角;当甩盘转速900 r/min、喂入量4 275颗/s、喂入角110°、喂入位置角64°时均匀性变异系数为12.48%,仿真验证和实际试验验证结果与优化结果相吻合。机器前进速度为5.4 km/h时实际工况动态仿真得到工作幅宽内均匀性变异系数为11.43%,满足田间撒肥作业要求。研究结果可为颗粒肥撒施机设计提供参考。

Fertilizing operation is an important link in grain seeding, which plays an important role in ensuring the high yield. Fertilizer spreaders often are used in the operating process. At present, the spreading uniformity of most of the machines needs be improved. In order to improve the spreading performance, in this study, a centrifugal fertilizer spreader with a rotating swing disk with 16 involute spiral guide rails was studied and dynamic characteristic analysis of fertilizer particle was performed. A single factor simulation analysis on rotational speed of disk, feeding angle, feeding quantity and angle of feeding position was conducted using a disk rete element model based on theoretical analysis results. Influence of various factors on the spreading uniformity of the centrifugal swing disk was discussed. The working range of the parameters was derived. The rotational speed of disk ranged from 700 r/min to 1 100 r/min, feeding angle was from 70° to 110°, feeding quantity was from 2 000 particles to 6 000 particles per sencond, and angle of feeding position was from 50° to 90°. The urea with larger size was taken as the research material. The orthogonal regression rotation simulation experiment with four influencing factors was designed and the test indexes were coefficient of variation of fertilizer distribution on the lateral width direction. The simulation experiments on fertilizer spreading performance and target parameter optimization was done, and the static verification test was carried out. Multivariate nonlinear regression model was established and the affecting importance of factors on the uniformity and response surface analysis was finished. The experimental data were processed and optimized by Design-expert 8.0.6. The results showed that the interaction between angle of feeding position and rotational speed of disk, angle of feeding position and feeding angle had important influence on spreading uniformity. The order of importance was followed by rotational speed of disk, feeding angle, feeding quantity and angle of feeding position. The minimum uniformity coefficient of variation were 12.48% when rotational speed of disk, feeding quantity, feeding angle and angle of feeding position was 900 r/min, 4 275 per second, 110° and 64°, respectively. With the optimal parameters, the results of simulation and bench testing were mostly in agreement. The simulation research on fertilizer spreading performance of fertilizer spreader by EDEM was proved to be feasible. In order to verify operating effect under actual working conditions, the dynamic simulation research of multi-track fitting and superposition was carded out. The results showed that uniformity coefficient of variation were 9.92% and 11.43%, respectively when the forward speed of a machine was 0.5 m/s and 1.5 m/s. The fertilizer spreader can meet the technical requirements of field operations. The centrifugal fertilizer spreader with a rotating swing disk provides better working performance. The research results provide a theoretical reference for design and optimization of the granular fertilizer spreader with a spinning swing disk.