Experimental and numerical investigations of high-head pumped-storage power plant at speed no-load

Decaix, Jean (School of Engineering, HES-SO Valais-Wallis, HEI, HES-SO // University of Applied Sciences Western Switzerland) ; Hasmatuchi, Vlad (School of Engineering, HES-SO Valais-Wallis, HEI, HES-SO // University of Applied Sciences Western Switzerland) ; Titzschkau, Maximilian (Kraftwerke Oberhasli AG (KWO), Grimsel Hydro, Innertkirchen, Switzerland) ; Rapillard, Laurent (School of Engineering, HES-SO Valais-Wallis, HEI, HES-SO // University of Applied Sciences Western Switzerland) ; Manso, Pedro (Plateforme de constructions hydrauliques (PL-LCH), Lausanne, Switzerland) ; Avellan, François (Laboratoire de machines hydrauliques (LMH), EPFL, Lausanne, Switzerland) ; Münch-Alligné, Cécile (School of Engineering, HES-SO Valais-Wallis, HEI, HES-SO // University of Applied Sciences Western Switzerland)

Due to the increasing integration of new renewable energies, the electrical grid undergoes more frequent instabilities. Hydroelectric power plants, particularly pumped storage plants, are well suited for grid control. However, this objective requires extending the operating range of the machines and increasing the number of start-up, stand-by and shut-down procedures, which reduces the lifespan of the machines due to high mechanical stresses. The current study focuses on a pumped-storage power plant equipped with ternary groups. Recently, cracks on the runner blades of the Francis turbine have been observed without finding a clear explanation for their onset. During this period, the number of starts and stops per day has strongly increased. In order to better understand the origin of the fatigue of the turbine runner, external and on-board measurements along with CFD and FEM investigations have been performed. The on-board measurements provide evidence high mechanical stresses on the runner blades during the synchronization of the machine at speed no-load (SNL) operating condition. The frequency spectrum observed on the various signals suggests that the high stresses are linked to the excitation of one of the runner modes by some flow instabilities, which is supported by the CFD and FEM analyses.


Conference Type:
full paper
Faculty:
Ingénierie et Architecture
School:
HEI-VS
Institute:
Institut Systèmes industriels
Subject(s):
Ingénierie
Publisher:
Kyoto, Japan, 16-21 September 2018
Date:
2018-09
Kyoto, Japan
16-21 September 2018
Pagination:
10 p.
Published in:
Proceedings of 29th IAHR Symposium on Hydraulic Machinery and Systems, 16-21 September 2018, Kyoto, Japan
Appears in Collection:

Note: The status of this file is: restricted


 Record created 2019-01-15, last modified 2019-01-15

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