Kaplan Turbine

Kaplan turbines are reaction turbines. They operate in water heads ranging from 10 to 70 meters, unlike Pelton and Francis Turbines, which require higher heads. The reason they are manufactured is to provide higher efficiencies in low-head, high-flow applications, where Francis turbines are less effective.

The feature that makes Kaplan turbines superior is their adjustable blades, which change for different flow conditions. In addition, automatically adjusted wicket gates control water direction and flow.

Because Kaplan turbines operate in harsh environments where the flow velocity is pretty high, the material used must be durable and resistant to tear and wear. Runner blades and wicket gates are mostly made of stainless steel, on the other hand, the spiral casing is constructed with cast or reinforced steel.

Working Principle

Water enters the spiral casing, and hits stay vanes smoothly one by one. Stay vanes direct the flow toward the wicket gates, which control the velocity of the water before it reaches the runner. Blade size and angles are determined by the desired output, and the angle changes depending on the seasonal flow conditions.

Energy Conversion

The runner with adjustable blades then receives the water. Both the reaction and lift forces cause the runner to rotate.

The adjustable blades’ angle changes in different flow conditions. By doing that engineers ensure the highest efficiency is provided.

The rotating shaft connected to the runner transfers the mechanical energy to the generator, which then converts it into electricity.

Additionally, Kaplan turbine’s output ranges between 5 – 200 MW with runner diameters of 2 – 11 m.

In conclusion, Kaplan turbine is a preferable choice in conditions of low-head and high flows. Their adjustable blades and automated wicket gates ensure it work with maximum efficiency. Kaplan turbines play a crucial role in hydroelectric power generation as a result of their adaptability and efficiency.

Body of blades

Blades

Wicket gates

Eren Erden