柱塞式注肥泵的设计试验及精准施肥应用

为解决水肥一体化应用中施肥流量随着灌溉管道工作压力变化而波动导致施肥浓度不均匀的问题,设计了一种额定流量为300 L/h、最大工作压力为1.0 MPa的柱塞式注肥泵,对柱塞泵进行不同行程比例和电源频率下的工作流量试验,建立了工作流量与电源频率、行程比例及灌溉管道压力的拟合公式.结果表明:研发的柱塞泵工作流量与电源频率、...

Design and test of piston injection pump and its application in precise fertigation

In order to solve the problems of uneven fertilization concentration caused by the flow rate fluctuation with the changed irrigation pressure of irrigation pipeline in the integrated application of water and fertilizer. A piston injection pump with rated flow rate of 300 L/h and maximum working pressure of 1.0 MPa was designed. Then characteristic performances of the piston injection pump were carried out under different stroke ratio and power supply frequency. The fitting formulas of flow rate with power supply frequency, stroke ratio and irrigation pressure were established. The results showed that the working flow rate of the piston injection pump was very significantly positively correlated with the power frequency and stroke ratio, but significantly negatively correlated with the irrigation pressure. The flow rate measurement accuracy expressed by relative standard deviation(RSD)ranged from 0.09% to 1.43%. When the stroke ratio was 100% and the power frequency was 50 Hz, as the irrigation pressure increased from 0.1 to 0.5 MPa, the drop of the flow rate was 14.22 L/h, accounting for 4.58% of the average flow, and the maximum RSD was only 0.38%. It is indicated that the flow rate of the piston pump is very stable and can meet the needs of different working irrigation pressure of sprinkler irrigation and micro-irrigation water and fertilizer integrated system. In addition, taking the piston injection pump as the core component, the control strategy of only changing the power frequency of the piston injection pump was proposed this paper. It has the advantages of simple control algorithm, accurate flow regulation and low investment cost. It is suitable for precision fertilization of water and fertili-zer integration.