Author(s): Zhiyan Yang; Yongguang Cheng; Fang Cai

Linked Author(s): Yongguang Cheng

Keywords: Three-dimensional CFD; Load rejection; Transient process; Regulating system; Hydraulic turbine

Abstract: Both the flow patterns in hydraulic turbine and the governor regulating system of turbine-generator unit have great influence on the operation stability of units, but they were treated separately in previous studies. In this paper, the equation for regulating system is cooperated into the three-dimensional (3D) computational fluid dynamics (CFD) model of a hydraulic turbine, for attempting the simulation of the small disturbance transient processes in hydropower plants. The 15% load rejection transient process for a model pumped-storage system with a low specific-speed pump turbine is successfully simulated; reasonable torque, speed and other macro parameters are provided; the flow patterns inside the runner are analysed. The results show that the regulation characteristics of the small fluctuation are acceptable and accordant with practical experience, with the stability guaranteed and the attenuation of fluctuating parameters obvious. These verify the feasibility of using 3D CFD to simulate the load rejection transient process, and lay a foundation for further studying the starting stability of units.

DOI: https://doi.org/10.1088/1755-1315/163/1/012079

Year: 2017