Análise energética e desempenho de um coletor solar cilíndrico parabólico auxiliado por sistema de rastreamento solar aplicado no processo de dessalinização térmica

Abstract

In Brazil and in countries that are developing economies, there is a tendency for them to invest heavily in the application of renewable energy sources. This has happened due to the growth in demand for energy, mainly due to the increase in population and the evolution of industrial activities. In addition, another serious problem related to this theme is access to drinking water by the population, especially in states in the Brazilian semi arid region (AL, BA, CE, PB, PE, PI, RN, SE, MA and MG). In this context, and considering the energy potential of these states, solar energy represents one of the viable renewable sources for use in these regions. It can be used with the use of solar concentrators that are commonly used in solar thermal systems in which the working fluid reaches high temperatures (60ºC to 400ºC). This research analyzed the energetic influence of the Parabolic Solar Concentrator technology aided by a solar tracking system in a water desalination process. In this work, the data collected through temperature sensors fixed on the external surface along the absorber located in the focus of the parabolic trough of a parabolic solar concentrator developed to supply energy to a thermal desalinator, and also by the solar radiation sensor ( pyranometer), placed on the structure of the concentrator. In addition to these sensors, the solar concentration system was assisted by a solar tracking mechanism that was responsible for always keeping the solar radiation collector in a position of maximum use of the sun's rays. The concentrator had an optical efficiency of approximately 81%, reaching average thermal efficiency values between 21.8% and 24.7% under conditions of m aximum solar radiation of 990 W/ m². The rate of production of desalinated water was estim ated to reach average values of 68.67 ml/min and 82.10 ml/ min, being able to provide an average production of 24.63 liters of desalinated water per day.