Análise do aproveitamento energético em redes de distribuição de água com a utilização de bombas como turbina (BFT)

Abstract

Water distribution networks (WDNs) need adequate pressure to deliver water to users. In some cases, the pressure is excessive and is usually dissipated by pressure reducing valves (PRVs), which end up wasting this energy contained in the network. Due to the worldwide need to seek renewable energy generation technologies, researchers have studied the possibility of replacing these PRVs with a pump running as turbines (PAT). It is a centrifugal pump operating inversely in substitution of PRVs. As WDNs operate under varying conditions of flow and pressure, the prediction of PATs still encounters difficulties, which impairs their effective control of pressure when replacing PRVs. This work analyzes a real network with pressure management problems. Different locations of PRVs to control network pressure were proposed in two hydraulic simulations. The PRVs were replaced by PATs and it was evaluated to see which was the best configuration for greater control of supply pressure. The prediction of these machines was performed by a joint method that analyzes the entire operating range. In addition, the amount of energy recovered and the environmental benefits were estimated. The results show the pressure control in the two simulations (S1 and S2), in S1, the pressure in the most critical node was reduced in 42.80% and the energy recovery was 52 kWh/day. In S2, the pressure was reduced in 45.21% and the energy recovery was 190.96 kWh/day; in addition to better controlling the pressure, the energy recovery results were 267% higher than S1. The joint method, proposed in the research, simplified the PAT selection and prediction process, and it was possible to conclude that these machines should be installed in parallel with the PRVs, considering that, when the PATs cannot adjust the pressure at some times of the day, the valves do.