出砂油井潜油电泵叶轮结构优化

Optimization of Impeller Structure for Electric Submersible Pumps in Sanding Oil Wells

潜油电泵应用于出砂油井时,砂粒对离心泵叶轮磨损严重,导致增压性能降低,甚至机组失效。为了明确叶轮磨损规律,优化叶轮结构参数,开展了含砂条件叶轮磨损特性仿真分析。建立了全尺寸离心泵几何模型,利用六面体结构化网格进行网格划分,基于CFD数值模拟技术,优选RNG k-ε湍流模型和离散相模型模拟固-液两相流场,以冲蚀磨损率为评价指标,通过SIMPLEC算法进行求解。实验采用正交设计方法,解决多因素敏感分析的交互影响。结果表明:出口宽度对叶轮磨损影响最大,叶包角、入口宽度和叶片数次之,出口宽度越大,冲蚀磨损率越小。最优叶轮结构参数为出口宽度21.1 mm、叶包角90°、叶片数10、入口宽度13.6 mm,相比于原泵型叶轮结构,新叶轮几何形态更发散。研究成果对同类油井泵型选择提供了参考依据,也为潜油电泵制造商开展防砂优化设计提供了理论支撑。

The electric submersible pump(ESP)is used in oil well sanding,and the impeller of the centrifugal pump will be severely worn by sand particles,resulting in a decrease in suction performance and even pump failure.In order to clarify the wear pattern of the impeller and optimize the structural parameters of the impeller,a simulation analysis of the wear characteristics of the impeller under sand conditions was carried out.A full-scale geometric model of the centrifugal pump was established,in which a hexahedral structured mesh was used for the grid,CFD technology was used for the numerical simulation,RNG k-εturbulence model and discrete phase model were used for the simulation of the solid-liquid two-phase flow field,erosion wear rate was selected as the evaluation index,and SIMPLEC algorithm was used for the calculation.The orthogonal design method was adopted in the experiment to address the interactive effects of multi-factor sensitivity analysis.The experimental results show that the outlet width has the greatest effect on the wear of the impeller,while the effects of the blade inclusion angle,inlet width and number of blades are reduced accordingly.The larger the outlet width of the impeller,the lower the erosion wear rate.The optimum structural parameters for impeller outlet width,blade inclusion angle,number of blades and inlet width are 21.1 mm,90°,10 and 13.6 mm,respectively.Compared with the original impeller structure of the pump type,the geometry of the new impeller is more divergent.The research results provide a qualitative basis for the selection of pump types for similar oil wells,and also provide theoretical support for the optimization of sand resistance performance in the field of ESP manufacturing.