Author(s): F Khan; A Kumar; T Staubli

Linked Author(s):

Keywords: Pelton turbine; Needle force; Injector regulation; Servomotor design

Abstract: In hydropower plants, the Pelton turbine is a commonly used hydraulic turbine where flow is regulated with a dual mechanism of needle and deflector. The needle is controlled by a servomotor and governor system, where the flow rate varies by adjusting the needle strokes. The needle is operated under the hydraulic force caused by the high-water pressure inside the injector acting on the needle surface. The objective of computing the force balance in a Pelton injector is to determine the force to be supplied by the servomotor. The closing trend is crucial to design the injector for safe operation during an emergency. In this study, the function of the needle and nozzle curve generalizes the variable needle surface area, allowing the geometric properties of the nozzle and needle to be suitable for the needle force evaluation. The single-axis force transducer, which is mounted on the needle rod, has been used in the experimental method for determining the needle forces. The experimental findings are compared to analytical calculations and serve as validation for the accuracy and reliability of the computed results obtained through the analytical approach.

DOI: https://doi.org/10.1088/1742-6596/2752/1/012027

Year: 2023