Efficiency Deterioration in Small Pelton Turbines due to Sand Particles Led Bucket Erosion

Ph.D. Candidate: Mr. Tri Ratna Bajracharya

River conditions in Nepal are different from those in other countries. The influence of heavy rain during the monsoon period causes wide variation in river flow, land erosion and landslides. This produces high sediment land in the rivers. Even with sediment trapping systems, complete removal of fine sediment from water is impossible and uneconomical; hence most of the turbine components in Himalayan Rivers are exposed to sand laden water and subject to erosion of the turbine, causing reduction in efficiency and life components. The maintenance and repairing problems in the turbine components has often become a serious problem in the power production in Nepal. The parametric effects of these phenomena on the performance of turbine are not yet established. Therefore, present study is aimed at identifying the types and extent of the erosions caused by sand on the turbine components of Pelton turbines of small hydropower and recommending measures to prevent them with the view of improving the efficiencies of the turbines. The main objective of the study is to determine the sand erosions of splitter and surfaces of runner buckets and their effects on the efficiency of Small Pelton Turbines in operation to different parameters.