Author(s): Carolin Friz; Frederic M. Evers; David Felix; Robert M. Boes
Linked Author(s): Robert Boes
Keywords: Reservoir sedimentation fine sediment venting hydroabrasion hydropower Francis turbines
Abstract: Large volumes of sediment are transported annually into hydropower reservoirs, resulting in a reduction of energy storage capacity and impairing the functionality and safety of intake and outlet structures. Given increasing global energy demands, effective sediment management strategies are essential. Current strategies address sedimentation via reduction, removal, or adaptive methods, yet systematic venting of fine sediments through power waterways of hydropower plants remains underexplored. This study develops a monitoring concept for assessing sediment venting. The concept combines a methodology for quantifying hydroabrasion at partly coated Francis turbines with real-time sediment monitoring during venting operations. It includes measurements of the Francis runner coating thickness and referenced laser scans of the installed runner to enable future assessments of local and overall reductions in coating and steel thickness. The concept also incorporates monitoring suspended sediment concentrations over time to find a relation between the sediment load and hydroabrasion. This work aims at fine sediment venting as a countermeasure to reservoir sedimentation and at providing a method to quantify its effects on hydroabrasion in partially coated Francis turbines. Longer-term data collection will allow further insights into how sediment load affects turbine hydroabrasion, supporting sustainable hydropower operation.
Year: 2025