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| Characteristics and application of saddle-shaped zone in performance curve of axial-flow pump system |
| JI Dongtao1, LU Weigang1*, LU Linguang1, XU Lei1, LIU Jun2, SHI Wei2 |
| 1. School of Hydraulic Science & Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China; 2. The Eastern Route of South-to-North Water Diversion Project Jiangsu Water Source Co. Ltd., Nanjing, Jiangsu 210019, China |
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Abstract Based on the test data of the pump model for the SouthtoNorth Water Diversion Project and the model test data of pump system completed in the test rig of BeiFang Investigation, Design & Research CO, the characteristics of the saddleshaped zone of the head-flow performance curve of four typical axialflow pump systems and the corresponding axialflow pumps were analyzed and compared. It is found that there is only one saddleshaped in the saddleshaped zone of the head-flow performance curve of the axialflow pump system, while there are two saddleshaped head flow performance curve of the corresponding axialflow pump. The bottom head of the first saddle is close to the saddle bottom head of the pump system, while the bottom head of the second saddle is significantly lower than that of the saddle bottom head of the pump system. The experimental results of the flow pattern in the model test of the transparent pump system show that the second saddle bottom in the saddleshaped zone of the head-flow performance curve of the axialflow pump is a false appearance caused by the influence of the secondary backflow during the test measurement for the performance of pump model. The first saddle bottom head of the headflow performance curve of the axial-flow pump should be referred to the control head of the highest operating head of a pumping station with low lift for pump selection. If there is a model test data of the relevant pump system, the saddle bottom head of head-flow performance curve of similar pump system model test might be referred as the control head.
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Received: 09 February 2020
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