Authors

Abstract

This paper proposes a fertilizer mixing device that combines pressure relief return and mechanical agitation to address the issues in the current water-fertilizer integration equipment related to limited fertilizer mixing methods and inconvenient irrigation pressure regulation. The device employs different mixing modes for various fertilizer forms and uses pressure relief return to adjust irrigation pressure, thereby enhancing the efficiency of water-fertilizer mixing and optimizing energy consumption. The experimental results indicate that the reflux mode is suitable for liquid-type fertilizers which are fast dissolving and easy to diffuse, and its EC value is stable at about 6.60 mS/cm, which is close to the calibrated value of 6.80 mS/cm. The stirring paddle mode compensates for the reflux mode's weak mixing effect, making it suitable for solid powder-type fertilizers' mixing operation. The EC value remains stable at approximately 8.60 mS/cm when calibrated at 8.70 mS/cm. The “stirring paddle + two-way reflux” mode demonstrates the most robust mixing effect and is suitable for mixing solid granular fertilizers. When calibrated at 8.20 mS/cm, it stabilizes at approximately the calibration value after 105 s. This research provides technical support and a theoretical basis to accomplish efficient, energy-saving, and rational application of water-fertilizer integration across diverse fertilizer forms.

Abstract in Chinese

针对中国水肥一体化设备混肥方式单一、灌溉调压不便的问题，设计了一种混肥设备，在满足不同形态肥料高效混合的同时，可通过泄压回流的方式调节灌溉压力，降低系统能耗并提高水肥混合效率。为得到不同形态肥料水肥混合的效果，模拟分析了混肥过程中流体的流动行为及其力学特点，得出“搅拌桨+同向回流”模式促进流体域内整体对流，对轴向混肥有增强作用；“搅拌桨+反向回流”模式增强流体域底层液体剪切作用，对径向混肥有明显增强作用。为验证数值分析结果，进行了相应的混肥试验。结果表明：液态型肥料在回流混肥模式下，EC值稳定在6.60ms/cm左右，与标定值6.8ms/cm接近，能满足混肥要求；固态粉末型肥料分别在回流与搅拌桨混肥模式下，当标定值为8.70ms/cm时，EC值稳定在5.50ms/cm、8.60ms/cm左右，因此适合应用搅拌桨模式进行混肥作业；固态颗粒型肥料在搅拌桨与“搅拌桨+双向回流”混肥模式下，当EC标定值为8.20ms/cm时，分别经150s、105s稳定在标定值左右，因此从混肥效率看“搅拌桨+双向回流”模式适合对固态颗粒型肥料进行混肥作业。试验结果与数值模拟分析结论基本一致，为不同形态的肥料实现水肥一体化合理、高效、节能应用提供了理论依据和技术支撑。