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Hydro-abrasive erosion on coated Pelton runners: Partial calibration of the IEC model based on measurements in HPP Fieschertal
(2016)IOP Conference Series: Earth and Environmental ScienceAt medium- and high-head hydropower plants (HPPs) on sediment-laden rivers, hydro-abrasive erosion on hydraulic turbines is a major economic issue. For optimization of such HPPs, there is an interest in equations to predict erosion depths. Such a semi-empirical equation suitable for engineering practice is proposed in the relevant guideline of the International Electrotechnical Commission (IEC 62364). However, for Pelton turbines no ...Conference Paper -
Suspended sediment measurements and calculation of the particle load at HPP Fieschertal
(2016)IOP Conference Series: Earth and Environmental ScienceIn 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 ...Conference Paper -
Erosion of Pelton buckets and changes in turbine efficiency measured in the HPP Fieschertal
(2016)IOP Conference Series: Earth and Environmental ScienceGeometrical changes and material loss of Pelton turbine runners as well as changes in turbine efficiency were measured at HPP Fieschertal in Valais, Switzerland. The HPP is equipped with two horizontal axis Pelton units, with each 32 MW nominal power, 7.5 m3/s design discharge, 515 m head and two injectors. The injectors and the buckets are hard-coated. Hydro-abrasive erosion was quantified based on repeated measurements on two runner ...Conference Paper -
Optimization of hydropower plants with respect to fine sediment focusing on turbine switch-offs during floods
(2016)IOP Conference Series: Earth and Environmental ScienceAt 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 ...Conference Paper -
Acoustic measuring techniques for suspended sediment
(2016)IOP Conference Series: Earth and Environmental ScienceAcoustic signals can be used in various ways for suspended sediment monitoring. One possibility which lends itself particularly well in the context of hydropower plants (HPPs), is to use installations for acoustic discharge measurement (ADM). Such installations already exist at waterways of many HPPs. Similar to certain turbidimeters, the attenuation of the forward scattered signal travelling through the water-sediment mixture is correlated ...Conference Paper -
Real-time measurements of suspended sediment concentration and particle size using five techniques
(2016)IOP Conference Series: Earth and Environmental ScienceFine sediments are important in the design and operation of hydropower plants (HPPs), in particular with respect to sediment management and hydro-abrasive erosion in hydraulic machines. Therefore, there is a need for reliable real-time measurements of suspended sediment mass concentration (SSC) and particle size distribution (PSD). The following instruments for SSC measurements were investigated in a field study during several years at ...Conference Paper -
Hydro-abrasive erosion of hydraulic turbines caused by sediment – a century of research and development
(2016)IOP Conference Series: Earth and Environmental ScienceHydro-abrasive erosion of hydraulic turbines is an economically important issue due to maintenance costs and production losses, in particular at high- and medium-head run-of- river hydropower plants (HPPs) on sediment laden rivers. In this paper, research and development in this field over the last century are reviewed. Facilities for sediment exclusion, typically sand traps, as well as turbine design and materials have been improved ...Conference Paper