多级离心泵叶轮水力模型优化及性能分析

Optimization and performance analysis on hydraulic model of multistage centrifugal pump impeller

由于多级离心泵在原有的设计工况点下运行不稳定,并且在运行过程中发现满足要求的工况点偏离设计工况点较远。为使多级离心泵更好地满足运行要求,以某型号多级离心泵为样本,通过改造将其设计工况点由原有的Q=400m^3/h、H=152.4m变为Q=300m^3/h、H=174.2m,同时改造前后150～320m^3/h的性能曲线可以互换。原方案的叶轮采用的是3叶片,改造中考虑到与压水室的配合问题,叶片数取5。对改造前后的两个方案的内部流场解析,对两个方案的内外特性对比分析。通过分析发现在压水室为双蜗壳的结构中,5叶片方案的流场对称性要优于3叶片方案。流场对称性良好可以很好地平衡径向力,有利于改善运行中出现的不稳定现象。

For the multi-stage centrifugal pump running at the original design point is instability and the requirement operating point is far away from the design point in the operation process. In order to meet the operating requirements better changing its design point from Q= 400m^3/h, H=152.4m to Q=300m^3/h, H=174.2m. The original program use three blades impeller, the transformation taking into the impeller cooperate with the diffuser the number of blade select 5. Internal flow was analyzed on before and after the transformation, the internal and external characteristics of two schemes were compared. Through the flow field analysis of double volute structure, the symmetry of the 5 blade scheme is better than the 3 blade impeller. Flow field with good symmetry can be well balance the radial force and can improve the instability phenomenon in the.