Aperfeiçoamento e análise de coletores solares parabólicos com rastreamento manual

Abstract

A renewable source of energy that stands out from others for its disposition and quantity is Solar Energy, whose use is divided into two types of technology, Thermal and photovoltaic. Among the ways of capturing Solar Thermal Energy are the parabolic concentrators, which direct the solar rays to a small area. This technology allows the production of thermal energy through high temperatures and pressures. The Solar Thermal Energy captured in the concentrators can be used in showers, swimming pools or heaters, contributing to the saving of Electric Energy. It can also be converted into Electric Power through steam turbines. In this work, an experimental study was carried out with two parabolic trough solar collectors, 1.10m long and 0.60m wide. The objective was to analyze, through comparisons between collectors, the efficiency of each one using different materials in both the concentrator and the absorber, taking into account variables such as inlet and outlet temperature and flow rate of water in each collector for obtain the energy transfer rate in the form of heat. The whole experiment was carried out with manual tracking, in which a determined interval the time was sought to maintain the concentration focus of the solar rays in the absorber tube. At the end of the experiments, it was possible to determine which materials were among the best available resources for the collectors. In the case was using copper tube as absorber with a concentric glass tube around and in the parabolic concentrator the use of a plate of stainless steel of high brightness, increasing in this way the efficiency in the use of solar energy. It was possible to reach temperatures in the water around 75°C at the outlet of the collectors.