基于遗传算法的螺旋双轮排肥器优化设计与试验

Optimization design and experiments of double-spiral fertilizer discharge device based on genetic algorithm

【目的】对传统单螺旋排肥器排肥口物料流量随时间波动变化造成排肥均匀性低的问题进行改进。【方法】通过离散元法仿真分析单螺旋排肥器的排肥过程,针对单螺旋排肥器排肥均匀性低的问题设计一种螺旋双轮排肥器;通过理论分析确定该螺旋双轮排肥器理论排肥量,并建立以中心距、螺距、叶片高度、叶片厚度、螺旋叶片内径为设计变量,有效储肥体积为目标函数的数学模型,利用遗传算法对排肥器进行结构优化,并以史丹利复合肥颗粒为肥料对螺旋双轮排肥器进行台架试验验证。【结果】优化后结构参数分别为中心距49.8 mm,螺距32.5 mm,叶片高度15.2 mm,叶片厚度2.3 mm,螺旋叶片内径13.6 mm。对优化后的排肥器进行台架对比试验,在不同转速下螺旋双轮排肥器较单螺旋排肥器排肥均匀性波动系数平均减少26.62%,实际排肥量平均提升75.41%,并得到螺旋双轮排肥器转速与排肥量的线性函数方程。【结论】螺旋双轮排肥器解决了单螺旋排肥器的现存排肥流量波动问题,优化后的排肥器排肥均匀性更好,排肥量更大,且可实现转速变化控制精量施肥。

【Objective】The study was congducted to solve the problem of low uniformity of fertilizer discharge caused by the fluctuation of material flow at the discharge port with time in the process of ma-terial conveying by the traditional single-spiral fertilizer discharge device.【Method】Through EDEM simulation analysis of the single-spiral fertilizer discharger,a double-spiral fertilizer discharger was de-signed to solve the problem of low uniformity of single-spiral fertilizer discharger.Through theoretical analysis,the theoretical discharge quantity of the double-spiral fertilizer discharger was determined.A mathematical model with center distance,pitch,blade height,blade thickness and spiral blade inner diameter as design variables and effective fertilizer storage volume as objective function was estab-lished.The structure of the fertilizer discharger was optimized by genetic algorithm,and the double-spiral fertilizer discharger was verified by a bench comparison test with Stanley compound fertilizer par-ticles as fertilizer.【Result】The optimized structure parameters were 49.8 mm center distance,32.5 mm pitch,15.2 mm blade height,2.3 mm blade thickness and 13.6 mm inner diameter of the spiral blade,based on which the double-spiral fertilizer discharge device was bench tested with Stanley com-pound fertilizer pellets.The optimized fertilizer discharger was subjected to a bench comparison test.The fluctuation coefficient of fertilizer uniformity was reduced by 26.62%on average.The actual ferti-lizer discharging capacity was increased by 75.41%on average for the double-spiral fertilizer discharge device than the single-spiral fertilizer discharge device at different rotational speeds.Finally,the equa-tion of double-spiral fertilizer discharge device as a function of rotational speed and fertilizer dischar-ging capacity was derived.【Conclusion】The double-spiral fertilizer discharge device solves the existing problem of fluctuating fertilizer discharge flow of single-spiral fertilizer discharge device,and the opti-mized fertilizer discharger has better uniformity of fertilizer discharge,increased fertilizer discharge volume,and can realize the change of rotational speed to control the precise amount of fertilizer appli-cation.