Identification of the performance characteristics of a propeller pump as a propeller turbine in response to variations in rotational speed

Abstract

Innovations continue to be developed in the field of new and renewable energy, particularly in hydropower, namely the use of pumps as turbines to replace conventional turbines in decentralized energy systems for areas not yet connected to the central power grid, in order to meet basic needs. The object of this study is a 3-blade propeller pump model designed based on references from previous study, which includes a blade angle of 30°, three blades, and a blade thickness of 2 mm each. The model was fabricated using 3D printing technology with ABS (acrylonitrile butadiene styrene) material. This study addresses issues related to the use of pumps in reverse mode (turbine), particularly regarding the relationship between rotational speed and power, efficiency, and performance characteristics, by combining two approaches: computational fluid dynamics (CFD) simulation and experimental testing applied to a 3-inch water pipeline prototype installation. The results of the study show the performance curves of the propeller pump at various rotational speeds, namely 225–325 rpm, with efficiency values ranging from 30% to 75%, and for the pump operated as a turbine, ranging from 8% to 52%, with a generated power range of approximately 0.24 watts to 1.77 watts, as well as a range of power coefficients and tip speed ratios, namely 0.09–0.52 and 0.95–1.23. Based on these results, the propeller model design can assist and serve as a reference in the planning of pico-scale hydroelectric power plants to provide sustainable energy for the community