Pressure pulsation characteristics in a series-parallel centrifugal pump with unequal blade pitch
CHAI Liping1, YU Jiafeng2*, LI Yue1, YAN Hao1, CAO Linsong2
1. School of Mechanical Engineering, Hefei University of Technology, Hefei, Anhui 230009, China; 2. School of Automobile and Traffic Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
Abstract：Five kinds of impeller models with unequal blade pitch are established based on automatic balancing theory of rotor-bearing systems to explore the influence of unequal pitch on pressure fluctuation in a series-parallel centrifugal pump. Specially, the performance and pressure fluctuation characteristics of the pumps with these impellers are compared and analyzed to improve the operational stability of the pump. The results show that the head and efficiency of the pump decrease as θmin gets small regardless of running in parallel or in series. When θmin is equal to 56° or 58°, the efficiency is higher than that with equal blade pitch; particularly, the best efficiency appears at θmin=56°. An additional fluctuation energy amplitude peak occurs at 435 Hz, i.e. 1.5 times the blade passing frequency in unequal blade pitch cases, and the amplitude decreases gradually with increasing θmin. As a result, the concentrated distribution of pulsating energy has been mitigated. The distribution of pressure fluctuation amplitude is more uniform and stable but also the energy distribution is more reasonable at θmin=56° in terms of comparison of pressure pulsation characteristics and pulsation energy amplitudes in the dominant frequencies at the monitoring points positioned along the circumference of the volute.
柴立平,俞嘉枫*,李跃,燕浩,曹林松. 基于不等距叶片的串并联泵压力脉动[J]. 排灌机械工程学报, 2019, 37(9): 752-757.
CHAI Liping, YU Jiafeng*, LI Yue, YAN Hao, CAO Linsong. Pressure pulsation characteristics in a series-parallel centrifugal pump with unequal blade pitch. Journal of Drainage and Irrigation Machinery Engin, 2019, 37(9): 752-757.
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