Optimization of Hydropower Plants Regarding Hydro-abrasive Erosion

The hydro-abrasive erosion poses challenges for smooth and efficient operation of existing hydropower plants (HPPs) as well as planning for new HPPs. The loss in revenue is caused due to reduced generation on account of reduced efficiency, down time for repair and maintenance for restoring the machinery and other components. In this study, various optimization considerations required with respect to hydro-abrasive erosion at both the planning and the operation stage of a HPP are presented. The factors involved in each steps like unit sizing, selection and design of turbines, capacity of desanders, cut-off limits of sediment concentration for turbine switch-offs, preventive measures such as coatings etc. were discussed. Further, a case study of an operational HPP located in Indian Himalayas is presented where suspended sediments, hydro-abrasive erosion and reduction in efficiency were measured simultaneously. Available models were used with measured values to obtain various losses due to hydro-abrasive erosion. The cost of coating, a preventive measure, is compared with the losses in operating the uncoated turbine. A decision making criterion is also introduced.