Numerical Simulation in Turbine Mode of Counter-Rotating Type Axial Flow Pump (Preparation of Pump-Turbine Unit in Cooperation With Wind Power Unit)

Abstract

Pumped storage system contributes to adjust the electric power unbalance between day and night, in general. The pumping operation, however, may be unstable in the rising portion of the head characteristics, and/or bring the cavitation at the low suction head. To simultaneously overcome both weak points, the authors have proposed a superior pumping unit that is composed of counter-rotating type impellers and a peculiar motor with double rotational armatures. This paper discusses the operation at the turbine mode of the above unit. It is concluded with the numerical simulations that this type unit can be also operated acceptably at the turbine mode, because the unit works so as to coincide the angular momentum change through the front runners/impellers with that thorough the rear runners/impellers, namely to take the axial flow at not only the inlet but also the outlet without the guide vanes.

Multidisciplinary system design optimisation of oscillating water column power plants: a nonlinear stochastic approach

“…A contra-rotating electric generator has been introduced so that the gearbox can be eliminated. This unit could be used in small, mini, or micro hydropower, tidal or even pump storage units (Murakami et al, 2012). Two different runners were designed, validated by CFD, and then rig tested.…”

“…Kanemoto and Galal (2006) proposed a contra-rotating wind turbine driving a double-armature generator. The large front rotor and the smaller rear rotor drive the inner and the outer armature (Murakami et al, 2013) of the electric generator respectively. Such a configuration enables to generate more power than a conventional single-rotor wind turbine.…”