Investigation of a fast transition from pump mode to generating mode in a model scale reversible pump turbine

28th IAHR symposium on Hydraulic Machinery and Systems

Stens, C.^1 ; Riedelbauch, S.^1

University of Stuttgart, Institute of Fluid Mechanics and Hydraulic Machinery, Pfaffenwaldring 10, Stuttgart

70550, Germany^1

关键词: Dynamic pressures;    Linear variation;    Open-source code;    Reversible pump-turbine;    Rotational speed;    Simulations and measurements;    Steady-state simulations;    Time-dependent flow;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/49/11/112001/pdf
DOI  :  10.1088/1755-1315/49/11/112001

来源: IOP

【 摘 要 】

Pumped storage power plants are an efficient way to store energy at a large scale. In the last years, the changes between pump and turbine mode have become more and more frequent and the necessity of fast changes has increased. This paper analyses the flow in a model scale pump turbine during a fast transition from pump mode to generating mode by means of CFD. Results will be compared between two different mesh sizes and between simulation and measurement. A linear variation of rotational speed over time is chosen. A time-dependent flow rate through the machine is prescribed at the inlet. Due to the varying conditions, a fully transient analysis is carried out using the open-source code OpenFOAM®. The state of the machine at certain points of time during the transient is compared to the results for steady state simulations with identical boundary conditions. To characterize the phenomena in the guide vane channels, torque on selected guide vanes is evaluated as well as pressure at predefined locations. In the runner, pressure sensors are evaluated near the leading edge on pressure and suction side. In the draft tube, four dynamic pressure sensors in a plane below the runner are analysed. Frequencies and amplitudes are compared to simulation.