超大流量轴流潜水泵叶轮设计与优化

Design and optimization of super-large capacity submersible axial-flow pump impeller

基于升力法对超大流量轴流潜水电泵叶轮进行水力设计,采用计算流体动力学方法对超大流量轴流潜水电泵装置进行全流道数值模拟和性能预测,并对该水力模型进行优化,同时通过试验对计算结果进行验证.分析结果表明：原设计模型在叶轮压力面进口处存在较明显的局部高压区,吸力面进口附近存在明显低压带和局部高涡量区域,消耗较大的能量,是导致叶轮效率低的主要原因之一;通过调整叶片进口角度和叶轮转速2个参数进行模型优化设计,优化后模型叶片压力面的静压分布较均匀,吸力面低压区域相对较小且涡量分布均匀;优化设计明显改善了叶片表面的压力分布和空化性能,同时提高了机组的水力效率;优化后的水力模型性能预测结果与实验结果吻合较好,数值预测结果能够较为准确地反映轴流泵系统的水力性能.研究结果为该类泵水力模型优化和性能改进提供了参考.

The impeller blade of a super-large capacity submersibIe axial-flow pump was designed based on the airfoil theory, the flow in the pump system was simulated by using computational fluid dynamics （CFD） method and the pump performance was predicted. The pump hydraulic model was optimized based on the numerical simulations of three different hydraulic models, and verified experimentally. It was shown that there is a noticed high-pressure region near the blade pressure side and the leading edge in the original impeller, additionally near the blade suction side and leading edge there exists a low-pressure region and an intensive vorticity, which consumes considerable energy resulting in a poorer hydraulic efficiency. The original impeller was optimized by increasing the inlet blade angle and reducing the rotational speed, consequently the optimized impeller is subject to a more uniform static pressure distribution in the blade pressure side and a shrunk vortex zone in the suction side with even vorticity. Clearly. the Dump cavitation performance and hydraulic efficiency have been improved.The performance of optimized hydraulic model exhibits good agreement with the experimental data, in- dicating the numerical results can reveal the actual performance of a hydraulic model exactly. The methods adopted in this study may provide a reference for hydraulic model optimization and performance improvement of submersible axial-flow pumps.