气力斜盘式小麦宽苗带匀播排种器设计与试验

Design and Experiment of Pneumatic Swash Plate Wheat Wide-seedling-belt Uniform Sowing Device

摘要:

小麦宽苗带匀播是提高小麦单产的有效途径，针对现有小麦排种器用于宽苗带播种存在种子均匀性差、苗带宽度不够等问题，设计了一种气力斜盘式小麦宽苗带匀播排种器。建立了充种、携种和投种过程中小麦种子动力学模型，明确了影响排种性能的主要因素。借助仿真试验和台架试验，确定了排种器的最优结构和工作参数。仿真试验结果表明，当型孔直径为1.91mm、型孔类型为柱型孔、负压抽气口直径为32.18mm和排种盘倾斜角为20°时，型孔内流速和型孔两侧压强差处于利于排种状态，种群扰动效果较好；通过台架试验确定了最佳工作参数组合为工作转速30r/min、吸种负压4500Pa，其各行排量一致性变异系数（RCV）、总排量一致性变异系数（TCV）、排种均匀性变异系数（SUV）分别为2.04%、1.45%、9.87%，满足小麦宽苗带精量播种要求。研究结果可为小麦宽苗带匀播排种器的设计与应用提供技术支撑。

Abstract:

Wide-seedling-belt uniform sowing is an effective approach to improve wheat yield per unit area. To addresses the issues of poor uniformity and insufficient seedling belt width in existing wheat seeders for wide-seedling-belt, a pneumatic swash plate wheat wide-seedling-belt uniform sowing device was designed. Through theoretical analysis, a mechanical model of the seeding plate during the filling, carrying, and throwing processes was developed, which helped to identify and resolve the key factors influencing the performance of the seed metering device. Simulation tests and bench tests were conducted to determine the optimal structural and working parameters of the seed metering device. The results of the CFD simulation tests indicated that under the optimal structural parameters, specifically a hole diameter of 1.91mm, a cylindrical hole type, and a negative-pressure suction port diameter of 32.18mm, the flow velocity within the holes and the pressure difference across the holes were in an optimal state for seeding. The CFD-DEM coupling simulation tests further revealed that when the tilt angle of the seeding plate was set at 20°, the device exhibited an excellent population disturbance effect and minimal seed migration resistance. Furthermore, the bench tests determined that the optimal combination of working parameters was a rotational speed of 30r/min and a suction negative pressure of 4500Pa. Under these conditions, the row consistency variation coefficient (RCV), total consistency variation coefficient (TCV), and sowing uniformity variation coefficient (SUV) of each row were 2.04%, 1.45%, and 9.87%, respectively. These values met the requirements for wheat wide-seedling-belt uniform sowing. The findings can provide technical support for the design and application of wheat wide-seedling-belt uniform seeders.