Estimation of Reducing Unit Abrasion by Sediment Regulation Measures of Pumped Storage Power Stations on Sediment-Laden Rivers

Pumped storage power stations (PSPSs) are crucial regulators for accelerating the global energy structure transformation and developing a renewable energy-dominated power system. The sediment entering the reservoirs leads to capacity loss, while the fine-grained sediment carried by water during pumping and power generation can cause cavitation in penstocks and abrasion of turbine blades, which may lead to frequent shutdowns for overhaul. Taking a pumped storage power station as an example, whose lower reservoir is on a sediment-laden river, this study simulates the sediment concentration and its particle size through turbines under different sediment regulation measures. The unit abrasion rate and overhaul cycle are further predicted. The results indicate that the sediment concentration through turbines (SCT) and the suspended sediment transport rate entering the lower reservoir are positively correlated. The higher the SCT, the coarser the sediment particle size through turbines. For the lower reservoir with delta or conical sedimentation patterns, lowering the water level and shutting down pumping during sediment peak processes can free up the effective storage capacity, reduce the SCT by approximately 26%, and extend the overhaul cycle to 1.5 times. The study also systematically introduces a practical and feasible method for predicting SCT and turbine blade abrasion, servicing for the sustainability of PSPSs.