中比转数离心泵多工况设计

为了实现TS65-40-125型中比转数离心泵在实际运行中的水力性能需同时满足多个工况点的要求,借鉴在低比转数离心泵多工况设计中广泛应用的加大流量设计法,对其叶轮进行3次改进.采用Ansys Workbench 12对整个计算域进行结构化网格划分,并对网格无关性进行了分析,利用商业软件CFX进行数值模拟,进口边界设定为均匀来流,出口边界设定为压力出口,采用SST k-ω模型,分析了不同设计方案下叶轮内的压力、湍动能、速度分布,并对泵的外特性进行了预测,最后选取一个最优方案进行试验.结果表明：采用加大流量设计法,恰当的选取叶轮几何参数,可以有效地增加中比转数离心泵的扬程、提高水泵效率,拓宽水泵高效区.TS65-40-125型中比转数离心泵叶轮采用加大流量设计法改型后,设计点水泵扬程比原型对应工况点最多提高了5 m,在5个工况点效率基本满足国家标准要求.研究结果可为中比转数离心泵的多工况设计提供一定的参考.

Multi-operating-condition design of centrifugal pump with medium specific speed

In order to allow the hydraulic performance of type TS65-40-125 centrifugal pump with a medium specific speed to satisfy multi-operating-condition simultaneously,its impeller was redesigned three times by means of the enlarged design flow rate method.A structure grid was generated in Ansys Workbench 12 and the grid size-independence was analyzed.The pressure,turbulence kinetic energy,velocity distributions in those impellers and the overall performance curves were obtained with the commercial software CFX.Finally,one optimal impeller was identified and experiments were made against it.It can be concluded that the properly selected geometry parameters of the impeller can effectively improve head and efficiency of the centrifugal pump with medium specific speed and expand the high efficiency zone by using the enlarge design flow rate method.The head of the redesigned pump was improved as high as 5 m compared with the original one at the design point and the efficiency at five ope-rating points basically met the specifications in the related national pump standard of China.Some refe-rences are provided for the multi-operating-condition design of centrifugal pump with medium specific speed.