23. A Technical Evaluation of Performance Characteristics for Pump as Turbine Application

It is very important to gain a better understanding of pump series of different specific speeds when running in reverse mode. The pump is running in reverse mode to serve as turbine for mechanical rotational energy generation in the hydropower and processing plants. This review chapter employs a technical analysis as a tool to evaluate pump when running in reverse mode by assessing the technological development gathered from the literature.

The operational parameters discussed include head, flow rate, power, efficiency, and specific speed. The number of modified pump components includes the blade angle, impeller size and tips, edges of shroud and hub plates, volute casing attached with guide vanes, and modified inlet casing rings and eye enlargement. The internal characteristics also occurred in the form of swirl flow between blades and discharge part, time dependent on flow circulation, radial and axial thrust, blade angle variation, pressure pulsation, cavitation effects, and energy losses between blades, volute casing, and discharge part. Furthermore, the conversion methods discussed were related to pump efficiency, specific speed and constant values to predict the head and flow rate. The conversion methods are mostly used to select the off-the-shelf pumps to run as turbine. Therefore, this paper provides the technological development of running the pump in reverse mode that would give insights for further studies in the four knowledge areas that include operational parameter characteristic, pump component modification, internal flow characteristics at the full- and part-load conditions, and also the development of conversion methods related to pump geometry, fluid properties, performance and system curves to improve the off-the-shelf pump selection.