Improving reliability and efficiency of hydraulic turbines

Abstract

Abstract The article deals with new design solutions to improve the operating process based on new design solutions and effectively use hydraulic turbines for heads up to 800-1000 m, expand the operating range relative to flow rates and heads with high energy and cavitation indicators and reliability of operation on varying modes that differ from the optimum operating mode. On the basis of complex experimental studies of the flow pattern in a water passage and, first of all, in the hydraulic turbine inlet for heads of 400-500 m, this article reveals the causes of increased energy losses. The energy losses are caused by large vortexes occurring in the spiral casing; they distort the flow directed to the runner of the hydraulic turbine. Several ways for improving the operating process are proposed, including new design solutions. The issues of improving the operating process of various types of hydraulic turbines are discussed. This is done by creating an angular momentum upstream the runner blades, which is necessary for optimum operation of the hydraulic turbine due to flow inlet using nozzle vanes located around of the runner inlet. The advantages of new types of hydraulic turbines and a more advanced operating process are illustrated by the hill diagram of this turbine.