Preliminary Design and Construction of a Small Hydro turbine for Off-Grid Power Generation

Abstract

This study looked into the preliminary design and construction of a small-scale hydro turbine which could be deployed into riverine, remote and off-grid communities for power supply. The candidate hydro turbine that offers an attractive solution for power generation of the scale envisaged for small rural communities is the axial-flow turbine of the propeller-type. This turbine offers several key advantages, including ease of construction, reliability, ease of operation and maintenance, efficiency, and adaptability to various environmental conditions. This paper detailed a comprehensive design methodology that began with the geometric optimization of the turbine components of a 1kW axial-flow turbine operating with 1.5 m head and flow rate of 0.07 m3/s. CFTurbo, a hydro-turbine design software package, was used together with SOLIDWORKS to design and perform numerical simulations of the flow within the proximity of the turbine components using Computational Fluid Dynamics (CFD). This process involved detailed analysis and iterative steps leading to modifications that ensured the turbine performed optimally across a spectrum of operational conditions. Both analytical approach and physical tests were used to accurately appraise the turbine’s operation characteristics. The maximum turbine output power during an off-design point testing was 54W at 189 rpm, flow rate of 0.0205 m3/s and a head of 0.55 m, giving an efficiency of 61%.  The study concluded that there is sufficient local capacity to produce, using simple technology, axial-flow propeller type turbine that can be deployed as a viable option for small-scale hydro power supply to riverine and off-grid locations in Nigeria.