小麦宽幅匀播机多级分流匀种装置设计与试验

Design and Test of Multistage Diversion and Homogenization Device for Wheat Wide Soaking Machine

摘要:

小麦宽幅匀播技术有利于优化小麦群体结构,对于提高水肥利用效率及产量具有重要作用。增加播幅、提高匀播是宽幅匀播技术的核心,针对小麦幅宽300 mm、行距300 mm、滴灌带铺设在苗带中间位置的小麦宽幅匀播种植农艺要求,本文提出了一种基于多级分流原理的宽幅匀种装置,阐述其结构和工作原理,分析了种子流在输种管内运动情况,研究了分种圆柱、分种板运动模型,得到影响匀种性能的关键因素;利用EDEM建立了匀种装置动态模型,以排量一致性变异系数和播种均匀性变异系数为目标,分种圆柱半径、分种圆柱竖向距离和分种板倾斜角度为因素,进行不同播种量条件下单因素试验,获得各因素对排量、匀种性能的影响规律;以排量一致性变异系数和播种均匀性变异系数为评价指标,以分种圆柱半径、分种圆柱竖向距离和分种板倾斜角度为试验因素,进行二次正交旋转组合试验,获得最优结构参数为分种圆柱半径9 mm、分种圆柱竖向距离35 mm、分种板倾斜角度45°,在最优结构参数下排量一致性变异系数不大于3.72%,播种均匀性变异系数不大于21.6%。最优参数下进行匀种性能台架验证试验和田间验证试验,结果表明台架验证试验2项指标分别不大于3.16%和22.36%,田间验证试验2项指标分别不大于3.68%和20.69%。台架和田间验证试验结果与仿真试验相对误差小于5%,证明应用离散元法对宽幅匀种装置结构参数进行优化的结果可信。研究结果可为宽幅匀种装置结构参数优化以及提升播种效果提供理论参考。

Abstract:

Wide-row,uniform seeding technology for wheat helps optimize plant population structure and plays a crucial role in improving water and fertilizer use efficiency as well as yield. Increasing the seeding width and improving uniformity are at the core of this technology. In response to the agronomic requirements for wide-row,uniform seeding of wheat,specifically a row width of 300 mm,a row spacing of 300 mm,and drip irrigation tape laid in the center of the seedbed,a wide-row uniform seeding device was proposed based on the principle of multi-stage seed distribution,its structure and operating principles were described,the movement of the seed flow within the seed delivery tube was analyzed,and the motion models of the seed-distributing cylinder and seed-distributing plate were investigated to identify the key factors affecting seeding uniformity. Using EDEM,a dynamic model of the uniform seeding device was established. With the coefficient of variation for discharge consistency and the coefficient of variation for seeding uniformity as objectives,and the radius of the seed-distributing cylinder,the vertical distance of the seed-distributing cylinder,and the inclination angle of the seed-distributing plate as factors,single-factor experiments were conducted under different seeding rate conditions to determine the influence patterns of each factor on discharge and seeding uniformity. Using the coefficient of variation for discharge consistency and the coefficient of variation for seeding uniformity as evaluation metrics,and the radius of the seed-distributing cylinder,the vertical distance between seed-distributing cylinders,and the inclination angle of the seed-distributing plate as experimental factors,a two-factor orthogonal rotational combination experiment was conducted. The optimal structural parameters were determined to be a seed-distributing cylinder radius of 9 mm,a vertical distance between seed-distributing cylinders of 35 mm,and a seed-distributing plate inclination angle of 45°. Under these optimal structural parameters,the coefficient of variation for discharge consistency was no greater than 3.72%,and the coefficient of variation for seeding uniformity was no greater than 21.6%. Bench and field validation tests for seeding uniformity were conducted by using the optimal parameters. The results showed that in the bench tests,the two indicators were no greater than 3.16% and 22.36%,respectively,while in the field tests,they were no greater than 3.68% and 20.69%,respectively. The relative error between the bench and field validation test results and the simulation results was less than 5%,proving that the results of optimizing the structural parameters of the wide-row uniform seeding device by using the discrete element method were reliable. The findings can provide a theoretical reference for optimizing the structural parameters of wide-row uniform seeding devices and improving their seeding performance.