Operational Impact of Suspended Sediment on the Run-of-river Small Hydro Power Plants

Abstract

Silt erosion is a result of mechanical wear of components on account of dynamic action of silt flowing in the water coming in contact with wearing surface. Therefore, silt flowing with water passing through the turbine is the root cause of silt erosion of turbine components. While passing through the generating units, suspended silt in water is subjected to the force of gravity, viscosity, inertia, turbulence and cavitation. Combination of these forces makes silt movement highly complex under varying velocity profiles and pressure gradient. Estimating the operational impact of suspended sediment on the run-of-river small hydro power plants is inherently depends on the long-term background or baseline sampling of the sediment in intake streams. The purpose of this study is to investigate the suspended sediment distribution profile of run-of-river small hydro power plants. Major undertakings were carried out on particle size distribution (PSD) and suspended sediment concentration (SSC) for estimating the operational impact of suspended sediment on the run-of-river small hydro power plants. The study encompassed programs for suspended sediment and streamflow profiling at different river geological profiles as well as their potential impact on the operation of small hydro power plants.