Coating technology in hydro-turbines for sediment affected power plants: A review

Abstract

The sediment loads originated from Run-off-river reaches to the turbines as suspended particles, causing wear and tear of the mechanical components. In the case of power plants under Himalayan Rivers, the turbines need to undergo repair and maintenance in a regular basis, due to a substantial loss of material from the turbine components. Past research works have focused on minimizing the erosion in turbines by changing the design of runner and guide vanes, strategically operation of the power plant during the monsoon season, as well as application of the coating materials over the susceptible regions. This paper studies the suitable coating technologies that could be implemented for hydro turbines, in the context of hydro power plants exposed to sediment particles. The review has shown numerous materials and approaches of applying the coating, their performance evaluation using experiments and important findings. This paper also discusses on different methods of characterizing the coating, mechanical integrity as well as the tribological behavior of the coated material.