Exploring the effects of operating time and sediment minerals on hydro abrasive erosion in Pelton turbine

Abstract Hydro-abrasive erosion in the Pelton turbines is attributed to high jet velocity generated by high head and abrasive sediment particles in sediment laden flow. This study presents a part of the research study that focuses on investigating the effect of sediment minerals on hydro abrasive erosion in Pelton buckets. Experiments were conducted on a Pelton jet test rig with a Pelton runner of 10 kW equipped with 20 buckets of different material using four sediment minerals (muscovite, feldspar, garnet, and quartz), operating time (3 h, 6 h, 9 h, 12 h), erosion velocity (46.58 m/s), suspended sediment concentration (1500 mg/l), and sediment size range (90-150 μm). It was found that erosion increases with an increase in the operating time; however, the rate of erosion varies with the material. Among all the materials tested, 13Cr4Ni with WC-Co-Cr coating performed best under the action of sediment and offered the best resistance to erosion. The correlations between normalized erosion and operating time were developed for each bucket material corresponding to muscovite, feldspar, garnet, and quartz sediments, and the obtained exponents of operating time vary from 0.95 to 1.22.