Session: 03-10: Fluid Power

Paper Number: 130493

130493 - Rotor-Stator Interaction and Vortex Rope in the Reversible Pump-Turbine at Off-Design Conditions in Turbine Mode 

In recent years, an increase in pumped storage plants has been observed in response to rising demands for more flexible and reliable operation of backbone systems for electrical grid stability. The reversible pump-turbine needs to operate at off-design operating conditions in turbine mode to balance the electricity grid due to the variable and intermittent behaviour of solar and wind energy production. During these operating conditions, hydraulic instabilities such as rotor-stator interaction and vortex rope in the draft tube led to pressure fluctuations in the vaneless space between the guide vanes and runner, and the draft tube, respectively. Therefore, the reversible pump-turbine may experience fatigue and vibration, further causing the vibration in the local components of the powerhouse. Therefore, there is a need to study the pressure fluctuations in the vaneless space and the draft tube of reversible pump-turbine at off-design operating conditions in turbine mode. The present study used a reduced-scale high-head reversible pump-turbine model, and the shear stress transport (SST) k-ω turbulence model was used to carry out numerical calculations. The analysis was performed at the guide vane angle of 10°, 14°, 18.06° (best efficiency point), 24° and 33°, and at the best efficiency point head of 30 m.

Presenting Author: Bhushan Rode Indian Institute of Technology Roorkee