Pumps as Turbines (PATs) by Analysis with CFD Models

Abstract

Pumps as turbines (PATs) are the typical solution for electrification using micro hydropower plants (MHP) in the rural sector. Other engineering applications where lately the use of PATs have increased are irrigation, water supply, and energy recovery systems due to their availability, short delivery time, long service life, economic feasibility, construction, and maintenance advantages. However, selecting the suitable pump(s) is difficult because manufacturers only provide performance curves when operating in pump mode; therefore, there is no universal method to predict that issue. For this reason, theoretical, analytical, experimental, and numerical simulation research have been made to predict these curves and the PATs' performance. The present paper analyzes PATs with Computational Fluid Dynamics (CFD) based on advanced research. For this aim, information from a wide range of types of pumps with different rotation speeds was classified to examine case approaches, computational domains, mesh generation, boundary conditions, optimization of elements, and CFD package used to establish the effectiveness of this tool and to find characteristics which have not been enough investigated at present. Most studies used CFD simulations with ANSYS code and K-ε turbulence closure model, which presented adequate results. Finally, this paper shows that numerical simulations with CFD analysis were successfully carried out to determine pump performance and predict curves in direct and reverse mode, improving certain components and conducting more profound research on certain specific issues.