Index Method for Pumping Operation of Reversible Pump-Turbine

Abstract

The adaptability of the Winter-Kennedy index method [1] was examined, and consequently “Draft Tube Index Method” for Francis and diagonal flow pump-turbines under pumping operation were newly investigated experimentally. It is clarified that the Winter-Kennedy method is applicable to Francis pump-turbines, but not suitable to apply on diagonal flow pump-turbines with adjustable guidevanes, and that the draft tube index method, depending upon differential pressure between two pressure taps provided on the draft tube or on the air-pipe, indicates sufficient accuracy to apply on Francis and diagonal flow pump-turbines.