Authors

Abstract

In order to improve the seed supply performance of seed-supplying link of high-speed dense planting seeder of maize, an air-assisted spiral seed-supply device was designed and optimized. The kinetic model of maize seeds in the migration zone was established. Based on computational fluid dynamics (CFD) simulation, the pressure and velocity distribution in the axial plane were explored when the blower pressure was 4.0, 4.5, 5.0, 5.5, 6.0 kPa, respectively. A two-factor, five-level central composite design (CCD) experiment was conducted using blower pressure and rotational speed of spiral shaft as test factors and seed supply rate, coefficient of variation of seed supply rate stability and seed breakage rate as seed supply performance indicators. Explored the impact trend of interaction terms of factors on seed supply performance indicators. Based on the multi-objective variable optimization method, the optimal working parameter combination of the air-assisted spiral seed-supply device was determined and verified by bench experiments. The results showed that the optimal combination of working parameters was the blower pressure of 6.0 kPa and the rotational speed of spiral shaft of 80 r/min. Under the verification test, the seed supply rate, the coefficient of variation of seed supply rate stability and the seed breakage rate were 2933.21 g/min, 1.87% and 1.69%, respectively, and the relative error was within 5.5% compared with the optimized results. This study can provide a reference for the optimal design of the seed-supply device of the high-speed dense planting seeder.

Abstract in Chinese

为提高玉米高速密植播种机供种环节的供种性能，设计并优化了一种气送式螺旋供种装置。建立了玉米种子在迁移区的动力学模型。基于CFD仿真探究了气流送种区在风机压力分别为4.0、4.5、5.0、5.5、6kPa时中轴面的压强与流速分布。以风机压力、螺旋轴转速为试验因素，以供种速率、供种速率稳定性变异系数、种子破损率为供种性能指标进行了二因素五水平的中心组合设计试验，探究了因素的交互项对供种速率、供种速率稳定性变异系数、种子破损率的影响趋势。基于多目标变量优化的方法确定了气送式螺旋供种装置的最佳工作参数组合并进行了试验验证。结果表明:装置的最佳工作参数组合为风机压力6kPa、螺旋轴转速80r/min，验证试验下该参数组合的供种速率、供种速率稳定性变异系数、种子破损率分别为2933.21g/min、1.87%、1.69%，与参数优化结果相对误差在5.5%以内。本研究可为高速密植播种机供种装置的优化设计提供参考。