Performance evaluation of an eroded Pelton turbine and components

The evaluation of the condition of a Pelton turbine is very important for maintenance in hydropower plants and largely depends on the erosion stage and economic risks related to structural integrity and maintenance costs. This study evaluates how combined erosion in the different turbine components affects the general efficiency. The replicability of erosion pattern on curved surfaces, the use of 3D printing with controlled environment of a test rig, made it possible to evaluates the loss of efficiency for each component of the Pelton turbine. The analysis shows the losses for the eroded needles are similar and important like the losses from the bucket. The loss of efficiency for eroded surface has a relationship with the velocities creating a different affectation curve for each component. The losses found for all the components together started in 2.5% in high load until 9% in part load.