喷灌施肥系统水力耦合模型构建及压力分布影响因素研究OA

A hydraulic coupling model for light and small-scale sprinkler fertigation systems was developed to explore the impacts of fertilizer pump operation,sprinkler configuration,and working parameters on system hydraulic performance.The model integrates a water pump performance curve,a proportional fertilizer pump suction model,and a multi-outlet pipeline hydraulic calculation model.The fertilizer pump suction model,proposed based on experimental data,uses inlet pressure,inlet flow rate,and mother liquor concentration as independent variables.A comprehensive hydrodynamic calculation framework was established for the first time by coupling all components(water pumps,fertilizer pumps,pipelines,and sprinklers)based on the back-step method.Due to the strong nonlinearity of the model,a Genetic Algorithm(GA)was employed to solve it.A case study was conducted on a system with a 50ZB-30Q water pump,10PY2H sprinklers,and a D8R proportional fertilizer pump to analyze the impact of factors such as fertilizer pump operation,number of sprinklers,working pressure,nozzle diameter,and mother liquor concentration on pipeline pressure distribution.Results showed that compared with clear water irrigation,integrating the fertilizer pump increased the system's average specific energy consumption by 25%under different sprinkler number configurations.Interestingly,the fertigation process(even with dilute fertilizer)reduced the overall range of pipeline pressure fluctuations compared to clear water irrigation,which may be related to the periodic operation of the fertilizer pump.An excessive number of sprinklers(>11)tended to induce abrupt pressure changes,and a low sprinkler working pressure(0.22 MPa)increased system sensitivity to hydraulic disturbance.Conversely,increasing nozzle diameter(5.5 mm)effectively mitigated these pressure variations.Additionally,increased fertilizer concentration substantially elevated pipeline pressure,especially in systems with multiple sprinklers.The strong nonlinearity of these interactions underscores the necessity of prioritizing hydraulic stability in the optimization,evaluation,and precision control of sprinkler fertigation systems.