油麦兼用高速播种机气送式排肥系统设计与试验

Design and Experiment of Pneumatic Fertilizer Discharging System for High Speed Seeder for Rapeseed and Wheat

摘要:

针对外槽轮排肥器在高速作业中存在肥料供应不足、脉动断条，造成肥料连续性、均匀性不足等问题，设计了一种叶轮供肥、离心分肥、辅以气流输送的气送式高速排肥系统。对叶轮供肥装置结构、离心分肥装置导流头和凹面圆盘进行设计；通过EDEM仿真试验，验证了所设计的叶轮供肥装置供肥变异系数小于3.2%，明确了导流头曲线为带摩擦最速降线时肥料颗粒流速最快，确定了直线型、二次多项式曲线型、三次多项式曲线型3种凹面圆盘曲线的最优结构参数；开展3种曲线结构的凹面圆盘台架试验，确定直线型凹面圆盘作业效果最优。以仿真确定的供肥装置、带摩擦最速降线导流头和直线型凹面圆盘开展叶轮转速与离心圆盘转速工作参数匹配试验，结果表明，在各行排肥量一致性变异系数低于7%条件下，当叶轮转速为14.00~21.23r/min即前进速度为9.00~10.24km/h时，离心圆盘转速应大于168.2r/min；当叶轮转速为21.23~25.00r/min即前进速度为10.24~12.00km/h时，离心圆盘转速应小于150r/min。田间性能验证试验结果表明，在较优匹配工作参数下排肥系统总排肥量稳定性变异系数均不大于4.11%，各行排肥量稳定性变异系数均不大于6.94%。该研究为油麦兼用高速播种机高速施肥装置设计提供了参考。

Abstract:

In response to the issues of insufficient fertilizer supply and pulsating strip breakage during high-speed operation of the existing external trough-wheel fertilizer spreaders, which result in poor continuity and uniformity of fertilizer application, a high-speed air-assisted fertilizer distribution system was designed. This system featured an impeller for fertilizer supply, centrifugal fertilizer distribution, and air-flow assistance for transportation. The structural designs of the impeller feeding device, centrifugal distribution device flow deflector, and concave disk were completed. EDEM simulation experiments were conducted to verify the performance of the impeller feeding device, achieving a coefficient of variation of fertilizer supply stability below 3.2%. It was determined that the fertilizer particle velocity was the fastest when the flow deflector curve followed a friction-based brachistochrone line. The optimal structural parameters of three concave disk designs—linear, quadratic polynomial, and cubic polynomial—were determined. A bench test compared the performance of these three designs, and the linear concave disk had the most significant impact on operational effectiveness. Using the simulation-determined fertilizer feeding device, brachistochrone flow deflector, and linear concave disk, a matching experiment was conducted to determine the working parameters of the impeller speed and centrifugal disk speed. Results showed that under the condition that the variation coefficient of the consistency of fertilizer discharge volume was below 7%, when the impeller speed was 14.00~21.23r/min (corresponding to a forward speed of 9.00~10.24km/h), the centrifugal disk speed should exceed 168.2r/min;when the impeller speed was 21.23~25.00r/min (corresponding to a forward speed of 10.24~12.00km/h), the centrifugal disk speed should be below 150r/min. Field performance validation tests demonstrated that under optimal parameter matching, the variation coefficient of the stability of fertilizer discharge volume was not more than 4.11%, and the variation coefficient of the consistency of fertilizer discharge volume was not more than 6.94%. The research result can provide a reference for the design of high-speed fertilization devices for dual-purpose seeding machines used for crops such as rapeseed and wheat.