Optimization of hydropower plants with respect to fine sediment focusing on turbine switch-offs during floods

28th IAHR symposium on Hydraulic Machinery and Systems

Felix, D.^1 ; Albayrak, I.^1 ; Abgottspon, A.^2 ; Boes, R.M.^1

Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zürich, Hönggerbergring 26, Zurich

CH-8093, Switzerland^1

Competence Center for Fluid Mechanics and Hydro Machines (CC FMHM), Hochschule Luzern (HSLU), Technikumstrasse 21, Horw

CH-8093, Switzerland^2

关键词: Abrasive erosion;    Coarse particles;    Economic issues;    Generate electricity;    Hydropower plants;    Monitoring techniques;    Reservoir sedimentation;    Suspended sediment concentrations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/49/12/122011/pdf
DOI  :  10.1088/1755-1315/49/12/122011

来源: IOP

【 摘 要 】

At medium- and high-head hydropower plants (HPPs) on sediment-laden rivers, hydro-abrasive erosion in turbines is an important economic issue. In HPPs with headwater storage, reservoir sedimentation is another problem related to fine sediment. On the one hand, turbine erosion is mitigated by reducing the sediment load in power waterways. On the other hand, reservoir sedimentation may be mitigated by conveying more fine sediment through power waterways to downstream river reaches. To optimize the operation of HPP schemes on the long-term, it is recommended to find a balance between these options based on real-time data using available monitoring techniques. An operational measure to mitigate turbine erosion is to close intakes and switch-off turbines in periods of high suspended sediment concentration (SSC) and coarse particles, typically during floods. Prerequisites for such operation are (i) there is no obligation to generate electricity, (ii) real-time SSC measurements are available, and (iii) the value of the 'switch-off SSC' is known. In a case study at the high-head HPP Fieschertal, a switch-off SSC of 10 g/l was estimated. The economic analysis showed that it would have been clearly profitable to practice such a switch-off during the major flood in 2012 which had an SSC peak of 50 g/l.