Numerical simulation of flow characteristics of pump turbine with small guide vanes opening

Pumped-storage power plant is an essential part of a stable, safe and efficient grid to compensate the random nature of custom energy consumptions by storing extra energy during the off-peak time and delivering energy during the peak time. Reversible pump turbine is the key component of the pumped-storage power plant. As the frequent transition between different working conditions during normal operations of the pump turbines, stability is of major interest to the manufacturers and researchers. Among all the working conditions of pump turbine, flow characteristics of pump turbine with small guide vane openings together with the associated pressure fluctuations are still not fully understood according to the literature survey. In present paper, our efforts mainly focused on understanding the dynamic behavior of pump turbine in this region based on numerical simulations. During the data analysis, special attention has been paid to the pressure fluctuation within pump turbine especially in the region between stationary guide vanes and vaneless spaces.