Calculation method and experimental verification for axial thrust on centrifugal pump
LIU Zailun1,2, ZENG Jilai1, SHAO Ancan3, WU Xinrui3
1.College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Engineering Institute of Wenzhou Pump & Valve, Lanzhou University of Technology, Wenzhou, Zhejiang 325105, China; 3.PRE(Fujian)Pump Industry Co. Ltd, Songxi, Fujian 353500, China
Abstract:The accurate calculation of liquid pressure in the balance chamber is the key technology for axial thrust calculation of the impeller which has balance holes and double wear-rings on the centrifugal pump. The correction coefficient was cited, which is liquid pressure loss in the pump side chamber. The calculation of liquid pressure difference between the inlet of pump side chamber and rear wear-ring was resolved when there was liquid leaking in the side chamber. The IS80-50-315 type centrifugal pump whose speed had been reduced was taken as the research object. Specific area was changed by altering both the balance holes diameter and the rear wear-ring clearance. Then the characteristics of the mathematic model of liquid pressure in the balance chamber and axial thrust were researched under design conditions. The results show that the characteristic curves of the mathematic model for liquid pressure of the balance chamber can solve the key problem of the calculation of liquid pressure difference in the balance chamber under design conditions. The joint regulation by the two sluice valves, balance holes and rear wear-ring affects the axial thrust caused by liquid pressure difference in the area of ba-lance chamber. From the point of view of controlling axial thrust, the optimum matching relationship between the balance holes diameter and rear wear-ring clearance could be obtained according to the characteristic curve of axial thrust. The reliability of the mathematic model was verified by two test cases.
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