地热井用两级潜水泵内流熵产诊断及水力性能优化

Entropy generation diagnosis and hydraulic performance optimization of internal flow of two-stage submersible pumps for geothermal wells

为了提升地热井用潜水泵的运行效率,根据地热井用潜水泵的流动参数和实际运行工况,完成了两级潜水泵过流部件水力设计,并进行了全流道流动数值模拟和试验验证;采用熵产分析法定位了潜水泵内流场的高能耗区域,主要集中在级间交汇和动静部件干涉处;采用正交设计和结构参数敏感性分析方法,确定了结构参数对潜水泵性能的影响规律,以叶轮叶片出口角、出口宽度、叶片包角和导叶轴向长度为优化变量,以扬程和效率为优化目标,通过遗传算法、最优拉丁超立方采样和熵权TOPSIS法对两级潜水泵进行水力优化。结果表明,额定工况下,优化泵的扬程增加了24.9%,效率增加了5.7%,总水力损失减小了1024.9 W,高能耗区域明显降低,水力性能显著提升,分离流、二次回流和冲击流动等不良流动得到显著抑制;大流量工况处理能力大幅度提升,高效区间范围扩大了70%,运行稳定性得到显著提高。研究内容为潜水泵的设计及内流场研究提供理论指导。

In order to improve the operational efficiency of the submersible pump for geothermal wells,hydraulic design of the flow components of the two-stage submersible pump was completed based on the flow parameters and actual operating conditions of the submersible pump.The designed two-stage submersible pump was subjected to full channel flow numerical simulation and experimental verification;The high energy consumption area of the flow field in the submersible pump is mainly concentrated in the intersection of the stages and the interference of dynamic and dynamic components by using the entropy production analysis method.Orthogonal design and sensitivity analysis of structural parameters were used to determine the influence rules of structural parameters on the performance of the submersion pump.With exit blade angle of impeller,exit blade width of impeller,wrap angle of blade of impeller and guide vane axial length as optimization variables,and with head and efficiency as optimization objectives,the hydraulic optimization of the two-stage submersible pump structure was carried out by using genetic algorithm,optimal Latin hypercube sampling and entropy weight TOPSIS method.The results show that under rated working conditions,the optimized pump head increases by 24.9%,the efficiency increases by 5.7%,the total hydraulic loss is reduced by 1024.9 W,the high energy consumption area is significantly reduced,and the hydraulic performance is significantly improved.The adverse flow phenomena such as separation flow,secondary flow,and impact flow are significantly suppressed.The handling capacity under high flow conditions is greatly improved,with the efficient operating range expanded by 70%.The operation stability is significantly enhanced.The research can provide theoretical guidance for the design of submersible pumps and the study of internal flow fields.