Pelton turbine is an example of:

Explanation:

Pelton Turbine

Definition: A Pelton turbine is a type of hydraulic turbine that operates on the principle of converting the kinetic energy of a high-speed water jet into mechanical energy. It is specifically designed for high-head, low-flow rate applications where water is available at a high elevation and must be utilized for generating power efficiently. The Pelton turbine is a tangential flow impulse turbine, meaning the water jet strikes the buckets tangentially to the wheel's circumference.

Working Principle: The working of the Pelton turbine is based on the impulse principle, where the momentum of the water jet is transferred to the turbine buckets:

• Water from a high elevation is directed through a nozzle to form a high-velocity jet.
• The jet strikes the curved buckets (or blades) mounted on the periphery of the turbine wheel. These buckets are designed in the shape of double cups with a central ridge, which splits the jet into two halves, allowing smooth flow and efficient energy transfer.
• The force of the water jet causes the turbine wheel to rotate, converting the kinetic energy of the water into mechanical energy.
• The used water is then discharged at atmospheric pressure without creating any suction effect.

Key Characteristics of Pelton Turbine:

• It is an impulse turbine where the entire pressure energy of water is first converted into kinetic energy before striking the buckets.
• The flow of water is tangential to the wheel, classifying it as a tangential flow turbine.
• It is suitable for high-head (typically above 300 meters) and low-flow rate conditions.
• The specific speed of a Pelton turbine is relatively low, making it ideal for high-head applications.
• It is highly efficient for its design conditions and can achieve efficiencies up to 90% or higher.