滑刀开沟-气力引射式液肥雾化侧深施肥装置设计与试验

Design and experiments of the side-deep fertilization device with slidingknife furrow opener and pneumatic ejector for a liquid fertilizer atomizer

为提高肥料利用率,降低肥料对水田的污染,该研究结合侧深施肥技术与液肥优点,研制一种水田滑刀开沟-气力引射式液肥雾化侧深施肥装置。该装置采用滑刀式开沟器开沟,利用气力引射式雾化施肥器雾化和引射液肥,将液肥侧深施于水稻根区附近土壤。设计了气液同轴气力引射式雾化施肥器内腔结构,以喉嘴距、混合室(喉部)直径、气体压力为因素进行全因子土槽试验,分析各因素对排肥量(液肥质量流率)和耗气量(气体流量)的影响。结果表明,影响液肥质量流率的主次因素顺序为混合室(喉部)直径、气体压力、喉嘴距;影响气体流量的主次因素顺序为气体压力、喉嘴距、混合室(喉部)直径。采用EDEM离散元仿真软件进行仿真优化,利用加权评分法综合评判仿真试验结果,结果表明,在不同工作速度下,滑切角为32.5°、刃口角为45°时,滑刀式开沟器可获得较优的工作性能。开展土槽试验验证仿真结果,滑刀式开沟器入土深度为30 mm、前进速度为1.2 m/s时,牵引阻力实测值为8.5 N,仿真结果为6.9 N,相对误差为18%,土壤扰动面积仿真结果为1965.6 cm2;入土深度为50 mm、前进速度为0.6 m/s时,牵引阻力实测值为14.4 N,仿真结果为12.2 N,相对误差为15%,土壤扰动面积仿真结果为2137.2 cm^(2)。土槽性能试验结果表明,该装置在入土深度为30 mm,前进速度为1.2 m/s时,排肥量标准差为0.2427 g/s,与最大排肥量的相对误差为1.42%,施肥深度与入土深度的相对误差为4.4%;在入土深度为50 mm,前进速度为0.6 m/s时,排肥量标准差为0.4796 g/s,与最大排肥量的相对误差为2.13%,施肥深度与入土深度的相对误差为2.1%。研究结果可为水田液肥侧深施技术的应用提供参考。

This study aims to increase the fertilizer utilization rate for less fertilizer pollution in paddy fields.A side-deep fertilization device was developed to combine with the sliding-knife furrow opener and the pneumatic ejector for the liquid fertilizer atomizer using the side-deep fertilization and liquid fertilizer.The fertilizer was applied to the soil near the rice root zone.The structure of the inner cavity was designed for an air-liquid coaxial pneumatic ejector fertilizer atomizer.A full factorial soil bin test was conducted with the nozzle-throat distance,the mixer(throat)diameter,and air pressure.A systematic investigation was also made to explore the effects of each factor on the fertilizer discharge(liquid fertilizer mass flow rate)and air consumption(air flow).The findings indicate that the influencing factors of the liquid fertilizer mass flow rate were ranked in descending order of the mixer(throat)diameter,air pressure,and nozzle-throat distance.Similarly,the influencing factors of the air flow were ranked in descending order of the air pressure,nozzle-throat distance,and mixer(throat)diameter.The structural design was simulated and then optimized with the EDEM software.The Weighted Mark Method was used to comprehensively evaluate the simulation.The optimal performance was achieved in the sliding-knife furrow opener at various working rates when the sliding-cutting angle was 32.5˚and the cutting-edge angle was 45˚.A soil bin test was implemented to verify the simulation.The measured and simulated traction resistance were 8.5,and 6.9 N,respectively,with a relative error of 18%,where the simulated soil disturbance area was 1965.6 cm^(2),when the ditching depth of the sliding-knife furrow opener was 30 mm,and the forward speed was 1.2 m/s.Meanwhile,the measured and simulated traction resistance were 14.4 and 12.2 N,respectively,with a relative error of 15%,where the simulated soil disturbance area was 2137.2 cm2 when the ditching depth was 50 mm and the forward velocity was 0.6m/s.When the ditching depth was 30mm and the forward speed was 1.2 m/s,the standard deviation of fertilizer discharge was 0.2427 g/s,the relative error to the maximum fertilizer discharge was 1.42%,and the relative error between the ditching depth and the fertilization depth was 4.4%,according to the soil bin performance test.When the ditching depth was 50 mm and the forward speed was 0.6 m/s,the standard deviation of fertilizer discharge was 0.4796 g/s,the relative error to the maximum fertilizer discharge was 2.13%,and the relative error between the ditching depth and the fertilization depth was 2.1%.The finding can serve as promising guidance for the application of side-deep fertilization of liquid fertilizer in paddy fields.