Wicket gate trailing-edge blowing: A method for improving off-design hydroturbine performance by adjusting the runner inlet swirl angle

27th IAHR Symposium on Hydraulic Machinery and Systems

Lewis, B.J.^1 ; Cimbala, J.M.^1 ; Wouden, A.M.^1

Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park

PA, United States^1

关键词: Best efficiency point;    Electric power grids;    Electricity generation;    High-efficiency;    Off design condition;    Trailing edge blowing;    Trailing edges;    Turbine efficiency;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/22/1/012021/pdf
DOI  :  10.1088/1755-1315/22/1/012021

来源: IOP

【 摘 要 】

At their best efficiency point (BEP), hydroturbines operate at very high efficiency. However, with the ever-increasing penetration of alternative electricity generation, it has become common to operate hydroturbines at off-design conditions in order to maintain stability in the electric power grid. This paper demonstrates a method for improving hydroturbine performance during off-design operation by injecting water through slots at the trailing edges of the wicket gates. The injected water causes a change in bulk flow direction at the inlet of the runner. This change in flow angle from the wicket gate trailing-edge jets provides the capability of independently varying the flow rate and swirl angle through the runner, which in current designs are both determined by the wicket gate opening angle. When properly tuned, altering the flow angle results in a significant improvement in turbine efficiency during off-design operation.