David Felix


Last Name

Felix

First Name

David

ORCID

0000-0001-7624-910X

Organisational unit

01109 - Lehre Bau, Umwelt und Geomatik

Filters

2010 - 2019392020 - 202617
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Publications1 - 10 of 56
  • Research projects on reservoir sedimentation and sediment routing at VAW, ETH Zurich, Switzerland
    Item type: Journal Article
    Albayrak, Ismail; Felix, David; Schmocker, Lukas; et al. (2018)
    Hydrolink
  • Suspended sediment and Pelton turbine wear monitoring
    Item type: Conference Paper
    Felix, David; Albayrak, Ismail; Abgottspon, André; et al. (2012)
    Proceedings of the 17th International Seminar on Hydropower Plants (Viennahydro) & Pumped storage in the context of renewable energy supply
  • Schwebstoffmonitoring zum verschleissoptimierten Betrieb von Hochdruck-Wasserkraftanlagen
    Item type: Journal Article
    Boes, Robert; Felix, David; Albayrak, Ismail (2013)
    Wasser Energie Luft
  • Variation des Feinsedimentgehalts im Triebwasser infolge Speicherstollenbewirtschaftung
    Item type: Conference Paper
    Felix, David; Albayrak, Ismail; Boes, Robert (2014)
    VAW-Mitteilungen ~ Internationales Symposium, Wasser- und Flussbau im Alpenraum: 25.–27. Juni 2014 in Zürich: Band 1: Wasserkraft und Gewässerrenaturierung
  • Suspended sediment measurements and calculation of the particle load at HPP Fieschertal
    Item type: Conference Paper
    Felix, David; Albayrak, Ismail; Abgottspon, André; et al. (2016)
    IOP Conference Series: Earth and Environmental Science
    In the scope of a research project on hydro-abrasive erosion of Pelton turbines, a field study was conducted at the high-head HPP Fieschertal in Valais, Switzerland. The suspended sediment mass concentration (SSC) and particle size distribution (PSD) in the penstock have been continuously measured since 2012 using a combination of six measuring techniques. The SSC was on average 0.52 g/l and rose to 50 g/l in a major flood event in July 2012. The median particle size d50 was usually 15 pm, rising up to 100 μm when particles previously having settled in the headwater storage tunnel were re-suspended at low water levels. The annual suspended sediment loads (SSL) varied considerably depending on flood events. Moreover, so-called particle loads (PLs) according to the relevant guideline of the International Electrotechnical Commission (IEC 62364) were calculated using four relations between particle size and the relative abrasion potential. For the investigated HPP, the time series of the SSL and the PLs had generally similar shapes over the three years. The largest differences among the PLs were observed during re-suspension events when the particles were considerably coarser than usual. Further investigations on the effects of particle sizes on hydroabrasive erosion of splitters and cut-outs of coated Pelton turbines are recommended.
  • Hydro-abrasive erosion of Pelton buckets and suspended sediment monitoring
    Item type: Other Conference Item
    Abgottspon, André; Staubli, Thomas; Felix, David; et al. (2013)
  • Quantifizierung der Abnutzung von Peltonlaufrädern mittels Bildanalyse
    Item type: Conference Paper
    Marschall, Yannick; Felix, David; Boes, Robert (2019)
    Tagungsband: 21. Treffen junger WissenschaftlerInnen deutschsprachiger Wasserbauinstitute - JuWi 2019
  • Turbinenabrasion durch Feinsedimente im Triebwasser
    Item type: Other Publication
    Felix, David; Boes, Robert (2011)
    ESC Newsletter
  • Hydro-abrasive erosion on coated Pelton turbines: Nine years of measurements and temporary shutdowns of HPP Fieschertal
    Item type: Conference Paper
    Felix, David; Abgottspon, André; von Burg, Martin; et al. (2022)
    Hydro-abrasive erosion in turbines of hydropower plants (HPPs) at sediment-laden rivers is still a concern despite the application of hard-coatings. To further investigate the problem and support HPP operators to better cope with the fine sediment load and its consequences, a long-term research study was conducted at the high-head run-of-river HPP Fieschertal in the Swiss Alps. From 2012 to 2020, the sediment load, erosion and efficiency differences of the two 32 MW-Pelton turbines of the HPP were measured. To do so, a real-time sediment monitoring system was installed and procedures to monitor the efficiency of the turbines were implemented. In parallel, the costs of the refurbishment and replacement of the main turbine parts were tracked. The nine years of detailed data were used to optimize the HPP operation and the turbine maintenance. A key element of this optimization is to shut down the HPP in periods of exceptionally high suspended sediment concentrations (SSC). The threshold value above which the operation of this HPP becomes unprofitable, the so-called shutdown-SSC, was determined as 15 g/l (15 000 ppm). For reliable real-time measurements up to such high SSC, a Coriolis Flow and Density Meter (CFDM) has been installed at the intake in addition to a turbidimeter whose measuring range is limited to 6 g/l. The findings of this project, such as a combination of instruments for real-time SSC measurements and the procedure to determine the shutdown-SSC, can be applied to other medium- and high-head run-of-river HPPs at sediment laden waters to improve their economic and energetic efficiency.
  • Temporary shutdowns of the high-head run-of-river HPP Fieschertal to prevent excessive turbine erosion during floods
    Item type: Conference Paper
    Felix, David; Abgottspon, André; Albayrak, Ismail; et al. (2021)
    IOP Conference Series: Earth and Environmental Science
    Hydro-abrasive erosion on hydraulic turbines is economically and energetically important. To better understand the causes and consequences of turbine erosion and to further develop mitigation measures, the suspended sediment concentration (SSC) and size distribution of mineral particles in the turbine water of the 64 MW high-head run-of-river hydropower plant (HPP) Fieschertal, Switzerland, have been continuously measured since 2012. An innovative combination of measuring techniques is used: turbidimeters, single-frequency acoustics, densimetry, laser diffraction and gravimetric analysis of water samples. Automatic warnings have been defined in the HPP's control system to allow for systematic HPP shutdowns when the SSC in the valve chamber exceeds the threshold value of 10 g/l for at least 15 minutes. During the flood of July 29 and 30, 2017 with an SSC peak of 110 g/l, the intake was closed and the HPP was shut down for half a day. This prevented about 8000 tons of fine sediment from entering the HPP, which corresponds to 9 % of the turbines' annual suspended sediment load (SSL) in 2017, or 12 % of the SSL in an average year without a significant flood. If the intake had been closed one hour earlier, the SSL could have been further reduced by about 3000 tons. For an earlier closing of the intake in case of floods, the turbidimeter at the intake shall be complemented by an additional instrument capable of measuring also medium to high SSC. Apart from the described flood event, SSC peaks in the range of 5 to 20 g/l occurring typically in late summer were attributed to re-suspension events in the storage tunnel due to HPP operation.
Publications1 - 10 of 56