Eficiência energética aplicada em sistema de abastecimento público de água com reservatórios elevados – estudo de caso para a cidade de Uruguaiana - RS

Abstract

This study deals with the supply in progress by a pressurizing system in a region with 9975 inhabitants in the city of Uruguaiana-RS and by means of this one to describe an alternative of supply for this region demanding less electrical energy. This study was developed in 03 stages. In the first stage the characterization and diagnosis of the current water distribution system was carried out. In the second stage, the design of the proposed supply system was carried out. Finally, in the third stage, the technical and economic feasibility study of this proposed alternative was carried out. The obtained results showed that it is feasible to supply this region by replacing the existing pressurizing station with a bottomed reservoir installed 8 meters above ground level and with 10 meters of maximum water depth. From the technical point of view it was observed that the proposed alternative allows to reduce the consumption of electric energy by 33.65%. Water losses in the region are reduced from 30% to 23.4% by promoting lower and more stable pressures. Economically, the project presents Net Present Value of R$ 306,213.26, Internal Return Rate of 16.76% and Simple Payback of 6 years, proving its economic viability. It is concluded that pressurizing stations' on-the-go delivery systems may have hydraulic transient regimes that contribute to increased physical losses in the supply system. It has been found that for high loss supply systems it is feasible to adopt the proposed design given the great waste of drinking water and electricity.