Optimization of screw turbine design parameters to improve the power output and efficiency of micro-hydropower generation

Abstract

Micro-hydropower is one of the renewable energy sources that can be used to electrify the off-grid rural areas. Archimedes screw is a potential machine element that can be used as the micro-hydropower screw turbine for efficient generation of electricity at low head run-rivers, and surface irrigation sites. It is crucial to consider an optimization design approach to determine the optimum parameters of the Archimedes screw to increase the power output and efficiency. Different researches are ongoing to use Archimedes screw as a micro-hydropower turbine, however, the optimization of the Archimedes screw parameters are untouched yet. The aim of this research is to design and optimize the Archimedes screw to increase the power output and efficiency of screw turbine by using theoretical analysis, ANSYS CFD, and ANSYS Workbench response surface optimization methodology. In this research, the performance of Archimedes screw is investigated for a range of flow rates (0.01 m3/s, 0.015 m3/s, and 0.02 m3/s) and heads (0.5 m to 1 m) with various additional parameters such as pitch of screw, inner diameter of screw, and number of screw blades. The optimum design was obtained at a flow rate of 0.015 m3/s, water head of 0.7 m, and inclination angle of 35° that increased the efficiency of the screw turbine from 55.4% to 92.9% compared to the reference geometry. And also, at the optimum design parameters, the maximum power output is increased from 57.07 Watt to 95.69 Watt.