Guide vanes erosion and corrosion assessment: A comparative study of existing and manufactured guide vanes for improving energy generation

Abstract

Hydropower remains a vital renewable energy source, yet turbine performance (consequently energy generation) which is an underwater component, is severely affected by erosion-corrosion of guide vanes. This study investigates alternative materials to improve the longevity and efficiency of hydro turbines. The guide vanes at Waya Dam suffer from severe erosion-corrosion due to high sediment loads and water chemistry, leading to reduced efficiency and high maintenance costs. Identifying durable materials is essential to extend service life and optimize hydropower output. This study develops an improve guide vane and compares its erosion-corrosion resistance with that of the existing guide vane. The study also involved determining the hardness. The corrosion rate was measured using sediment-laden water. Two materials (stainless steel and cast zinc alloy) were tested for suitability. Stainless steel exhibited the highest hardness (214.58 HV) and the lowest corrosion rate (0.0004 mm/year), making it the most resistant to degradation. The existing guide vanes had significant wear and the highest corrosion rate (0.010966 mm/year). Casted zinc alloy showed moderate performance, being more resistant than the existing material but less durable than stainless steel. Stainless steel is the most suitable replacement for guide vanes in reaction turbines due to its superior resistance to erosion-corrosion. The findings support improved material selection for hydropower turbines, leading to increased efficiency, lower maintenance costs, and sustainable energy generation.