Pressure management and energy recovery in water distribution networks: Development of design and selection methodologies using three pump-as-turbine case studies

Abstract

Energy consumption in water distribution networks is a widely publicised problem. Similarly the control of leakage through pressure management in water networks has also received significant attention in the literature. This paper outlines progress on the development of micro-hydropower systems for energy recovery and pressure management in water distribution networks.Design and selection methodologies are outlined for pump-as-turbines (PAT) to recover energy and control pressure at 3 case study pressure reducing valves (PRV) in the water distribution network (WDN) of Dublin, Ireland. This investigation comprised the use of experimental characterisation of a laboratory scale prototype PAT, extrapolation of these results to larger scales using Suter and Affinity laws, and the assessment of their performance against real-world flow and pressure data. An assessment of existing PAT selection methodologies was also conducted and compared against the experimental data.The results of this investigation highlight that up to 40% of the gross power potential of an existing PRV could be converted to electrical energy using a PAT while also controlling pressure. Existing PAT selection methodologies did not concur well with the experimental results. The use of 2 PATs in parallel to increase the efficiency of the overall system achieved marginal improvements in performance.