Influencing Factors and Prediction of Turbine Sediment Concentration in Pure Pumped-Storage Power Stations on Sediment-Laden Rivers

This study investigates the sediment transport characteristics in the lower reservoir area of a pure pumped-storage power station (Pure-PSPS) to address the sediment abrasion issue under high sediment-laden conditions. By establishing a physical model and employing multivariate statistical analysis methods, we systematically reveal the multifactorial coupled influence mechanism of key parameters in the lower reservoir area on turbine sediment concentration (TSC), while developing a predictive TSC formula applicable to high-sediment Pure-PSPS based on sediment-carrying capacity theory and sediment mass conservation principles. The study indicates the following: (1) Under consistent basic parameters such as reservoir length, the decay rate of sediment concentration along the path from the reservoir inlet to the power station’s intake and outlet decreases to 30~80% under high inflow conditions, while under medium and low inflow conditions, the decay rate exceeds 80%. (2) The lower boundary of the median particle size adjustment range for suspended sediment gradually increases from 0.006 mm for 30- and 40-year flood recurrence intervals to 0.009 mm for an 80-year recurrence interval, and under the 80-year recurrence interval, the particle size fluctuation range converges to a high and narrow distribution of 0.009~0.011 mm. (3) The constructed linear regression model has an R2 value of 0.8. The inflow sediment concentration (standardized coefficient β = 0.36) exhibits the strongest explanatory power for the dependent variable, followed by inflow discharge (β = 0.345) and the height difference between the intake/outlet and the silted bed surface (β = 0.319). (4) By optimizing the Adomian decomposition method, dimensional analysis, and multiple regression techniques, and based on sediment-carrying capacity theory and sediment mass conservation principles, this study derived and fitted a predictive formula for TSC in high-sediment-laden Pure-PSPS environments with favorable validation results. The research not only clarifies the interactive relationship between high-sediment-laden flow and turbine sediment concentration in Pure-PSPS but also fills the methodological gap in predicting operational conditions for pure pumped-storage power stations under extreme sediment scenarios. The established regular patterns provide a scientific foundation for the design and feasibility assessment of similar Pure-PSPS projects in sediment-rich rivers.