Experiment on instantaneous characteristics in centrifugal pump during startup period
Li Zhifeng1,2, Wu Dazhuan1,2, Wang Leqin1,2, Dai Weiping1,2, Chen Fengqiu3
(1.Institute of Chemical Machinery Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China; 2.Engineering Research Center of High Pressure Process Equipment and Safety, Ministry of Education, Hangzhou, Zhejiang 310027, China; 3.Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China)
Abstract： To further research instantaneous characteristics in centrifugal pump during startup period, a centrifugal pump instantaneous performance test system was established. Experiments on the startup process of a centrifugal pump with ball valve fully opened, semi-opened and fully closed were carried out, respectively. At the same time of testing the instantaneous explicit performances, 2D instantaneous flow field on the pump test section were captured with particle image velocimetry(PIV) technique. The reasons causing test error and relationships between external characteristics and internal flow evolutions were discussed. The results show that the internal flow of the centrifugal pump appears intense instantaneous characteristics during startup period. For startup with valve fully opened, both the instantaneous head and power increase rapidly with rotational speed increasing, and the instantaneous flow rate shows cubic trait characteristic. For startup with valve fully closed, the maximum power shock reaches 1.5 times of the steady state. The internal instantaneous flow indicates the shock is caused by fluid mixing and mutually transfer of vortex energy. The bubble and low shooting frequency are the main reasons for the PIV test errors.
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