Análise do sistema predial de água fria visando o aproveitamento da energia dissipada na VRP

Abstract

The present article aims to bring an analysis of the water building system of a residential building with multiple floors in order to take advantage of the energy dissipated in the pressure reducing valves (PRVs). These valves are hydraulic devices that downstream pressure control applied in systems that have a pressure higher than 40 mca, limit established by ABNT NBR 5626 (ABNT, 2020). The process of residential verticalization has led to the construction of increasingly taller buildings, in this way, to preserve the integrity of the piping system and generate comfort to the users at the consumption points, it is necessary to install these valves along the distribution columns of water. However, from an energy point of view, PRVs dissipate pressure energy by adding a localized loss to the system. This loss of energy contradicts the pertinent precepts of rational use of natural resources. In this way, this energy that is currently dissipated can be used to turn on the equipment of energy transformation, which when is attached to a generator, can transform it into electrical energy, causing the reduction of generation costs and contributing to the minimization of the environmental impacts generated by this waste of resources. The production of energy in water transport systems are economically viable solutions since it takes advantage of a system already executed and in full operation, with guaranteed flow due to the constant distribution of water at the points of consumption of the building, and a source of renewable energy, clean and without environmental impacts. The analysis of the water building system aims to understand, estimate and propose a form to generate complementary energy to the already exist system, making the enterprise more efficient by having recovered and used an energy that was previously being lost in the building pipelines, that is, no longer being used. In this work, a 32-story residential building with 79.55 meters high was analyzed. To this enterprise were considered two Pressure Reducing Stations (PRSs), one on the 15th floor and the other on the 6th floor. Base on the evaluation carried out, considering the pressure and flow upstream of the PRS, it was estimated that the amount of energy that can be used in the condominium is 488.27 kWh/month, which represents the supply of electrical energy for 62 fluorescent lamps of 32 W that are in the common areas of the condominium. Despite the difficulty in becoming economically viable, the study shows that the system is technically possible to be implemented and have relevance from a social, environmental and scientific point of view.