Energy Recovery in Pressurized Hydraulic Networks

Abstract

This paper aims to evaluate the possibility of using non-utilized hydraulic energy in urban water distribution systems. For this purpose, the viability and possible alternatives of installing conventional turbines or pumps working as turbines (PATs=Pumps as Turbines) at the head of pressure hydraulic networks in two towns in the province of Huelva have been studied: Cañaveral de León and Aracena (Andalucía, southwest Spain). Sensitivity analyses are carried out for: (a) To study the feasibility and efciency of installing turbines or PATs in the hydraulic networks; (b) To determine the required hydraulic capacity of the turbines or PATs; (c) To analyse the installation points in the pipeline network; and (d) To evaluate the possible generation of electrical energy. The evaluation of the recover able amount of hydraulic energy in both water distribution systems requires the applica tion of the energy conservation equation, taking into account the calculation of load losses, the Darcy-Weisbach equation. A diagram energy height-fow rate with diferent working ranges of commercial turbines/PATs was used for the selection of the appropriate hydraulic machine. The results obtained of the Aracena hydraulic network show that the best solu tion would be the installation of a 2 kW BANKI that could generate an approximate annual energy of 17,52 MWh/year. In the Cañaveral de León water supply system a 0,75 kW BANKI turbine with an approximate annual energy generation of 6,57 MWh/year is pro posed as the best solution.