基于多目标模糊优化的低比转数多级自吸喷灌泵研究

Design of Low-specific-speed Multistage Self-priming Spray Irrigation Pump Based on Multi-objective Fuzzy Optimization

摘要:

在单级自吸离心泵基础上，提出了一种具有高自吸性能及优良外特性的多级自吸泵的自吸装置。基于多目标模糊优化设计，确定追求关死点扬程极大值、最大轴功率极小值的多目标优化模型，结合设计经验及工艺需求建立相关约束条件，并进行非线性极值求解，最后以最优解完成过流部件的水力优化设计。对多级自吸喷灌泵进行了外特性试验，发现原始模型泵的关死点扬程和最大轴功率分别为10.7m和250.4W，而新模型泵的关死点扬程和最大轴功率分别为13.3m和189.6W。

Abstract:

Based on the single-stage self-priming centrifugal pump, a kind of self-priming device of multistage self-priming pump with high self-priming performance and external characteristic was proposed. Based on the positive and inverse diffuser, the backflow device was creatively designed and composed of gas-liquid separation chamber, outer shell, self-priming cover plate and gas-liquid mixture chamber. The highpressure water of finalstage pump chamber was sent to the first-stage pump chamber through the backwater device, and the gaswater was mixed repeatedly in the self-priming process. When the self-priming was completed, backflow valve in the self-priming cover plate was automatically shut off under huge pressure difference, which effectively improved the efficiency of self-priming pump. Based on the multi-objective fuzzy optimization design, the multi-objective optimization model with the maximum head of off dead point and minimum value of maximum shaft power was determined. Combined with design experience and technological needs, relevant constraints were established and solved through nonlinear extremum. Finally, the hydraulic optimization design of flow components was completed with the optimum solution. By doing the external experiments of multistage self-priming spray irrigation pump, it was concluded that the head of off dead point and maximum shaft power met the demand, which provided a new reference for optimization design of pump.