Effect of concentration and size of sediments on hydro-abrasive erosion of Pelton turbine

Abstract

Hydro-abrasive erosion caused by suspended sediments is a severe issue leading to frequent generation losses and failure of hydropower components especially in geologically young mountains like the Himalayas. To study the erosion behaviour of different materials under the same erosive and hydraulic conditions, experiments were performed simultaneously with different range of velocity, duration of exposure, sediment size, and concentration on a 1:8 down scaled Pelton buckets from an Indian hydropower plant (HPP) located in Himalayas. This work extends the research of Padhy and Saini (2009) for application in Pelton turbines fabricated from 6 materials such as 3 kinds of steel, 2 kinds of coatings and bronze for head up to 200 m. The values of sediment concentration for the tests were 500, 1500 and 3000 ppm, values mostly found in the HPPs. The developed erosion models were used to predict the erosion of the Pelton buckets from the study plant and are useful for proper planning of preventive measures and operation of the HPPs.