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Influence of balance hole diameter on flow state at the inlet of centrifugal pump impeller |
LIU Zailun1,2, YANG Kaiyue1*, LU Weiqiang3, SU Danfeng1 |
1. College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Engineering Institute of Wenzhou Pump & Value, Lanzhou University of Technology, Wenzhou, Zhejiang 325105, China; 3. College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404000, China |
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Abstract In order to research the influence of the balance hole diameter on flow state at the inlet of the centrifugal pump impeller, the IS80-50-315 type centrifugal pump with speed reduced was taken as the research object, and an identical impeller with a series of impeller balance hole diameters of 0, 4, 6, 8, and 10 millimeters was used to predict the pump head, efficiency and shaft power. The velo-city vector and pressure distribution of impeller inlet with different balance hole diameters under the design condition of pump were studied, and the pressure fluctuation characteristics at the inlet of impeller were monitored. The results show that with the increase of the balance hole diameter, the head and efficiency decrease, but the shaft power increases. The change of pump head is more obvious under the small flow condition than under the large flow condition. With the increase of the diameter of the balance hole, the liquid flow velocity in the balance hole decreases, and the impact on the liquid flow of the impeller inlet gradually decreases. The pressure at the impeller inlet becomes uniform, improving the anti-cavitation performance of the pump. The pressure fluctuation amplitude in the main flow area of the impeller inlet decreases with the increase of the balance hole diameter, and the change of the average static pressure at the impeller inlet is gradually stable. This study provides a reference for selecting the diameter of the impeller balance hole.
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Received: 11 August 2018
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