A Performance Prediction Method for Pumps as Turbines (PAT) Using a Computational Fluid Dynamics (CFD) Modeling Approach

Abstract

Small and micro hydropower systems represent an attractive solution for generatingelectricity at low cost and with low environmental impact. The pump-as-turbine (PAT) approachhas promise in this application due to its low purchase and maintenance costs. In this paper, a newmethod to predict the inverse characteristic of industrial centrifugal pumps is presented. This methodis based on results of simulations performed with commercial three-dimensional ComputationalFluid Dynamics (CFD) software. Model results have been first validated in pumping mode using datasupplied by pump manufacturers. Then, the results have been compared to experimental data for apump running in reverse. Experimentation has been performed on a dedicated test bench installed inthe Department of Civil Construction and Environmental Engineering of the University of NaplesFederico II. Three different pumps, with different specific speeds, have been analyzed. Using themodel results, the inverse characteristic and the best efficiency point have been evaluated. Finally,results have been compared to prediction methods available in the literature.