Optimization of rectification for forebay and suction chamber of parallel circulation pump station
WANG Weishu1*, ZHEN Juan1,GUO Jiawei1, ZHAI Yuxin1,HE Youcai2,HUANG Xing2
1. School of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou, Henan 450045, China;2. Datang International Fuzhou Power Generation Co., Ltd., Fuzhou, Jiangxi 344000, China
Abstract：For solving the stubborn vibration problem of circulation pumps in large thermal power plants, numerical simulation methods were used to study the vibration of pumps. Multiple rectification schemes had been proposed to improve the bad flow pattern of the forebay and suction chamber. The Reynolds time averaged Navier-Stokes equations and Realizable k-ε turbulence model were used to perform the numerical simulation. The 3D flow was simulated under the original working condition by Fluent. The flow pattern of different rectification schemes was also simulated by Flunet. Appropriate rectification engineering measures were analyzed and selected. The simulation results show that the irregular design of the arc-shape water inlet channel and the rectangular forebay are triggering the high-speed water flow areas and the adhering to the wall, which are the main reasons giving rise to vibrate in the circulation pump. To eliminate the stubborn vibration problem of the circulation pump, the rectification measures of the arc-shaped current sharing plate can nice improve the flow patterns around the entire forebay suction chamber and bell mouth. Meanwhile, the high-speed water flow area in the forebay is reduced by the rectification measures, the wall biased flow phenomenon basically disappears in the suction chamber, and the flow pattern is uniform in the bell mouth area. The inlet condition of the circulation pump is uniform. Field tests prove that the implement of rectification measures is efficacious, the vibration of pump units is obviously eliminated, the operating efficiency of the circulation pump has also been improved. The research results can provide reference for similar engineering examples.
