Study on head characteristics of low-charge conditions of vertical centrifugal pump with medium-low specific speed

The head of the centrifugal pump at the zero-charge and low-charge conditions has direct influence on the pump startup. In this paper, a large-size single-suction and single-stage vertical centrifugal pump with medium-low specific speed, which used in the Ganhe pump-station of water transferring project from Niulan River to Dianchi Lake, was taken as the research target. The optimization on the basic design of impeller and guide vanes, was to study the pump´s head characteristics of the low flow conditions, especially focused on improving the head on the low-flow conditions by using the hydraulic design with CFD method and finally to get the optimal matching between impeller and guide vanes. The study was verified by both the model pump tests and prototype pump test at zero-charge condition. The results show that, the head of the low-charge conditions converted according as the results of the model pump tests is higher than the head analyzed by CFD method, the head of the prototype pump at the zero-charge condition has sufficient margin and meets hydraulic design requirements.