Diseño y construcción de un calentador solar cilíndrico parabólico con fines investigativos para la Escuela de Ingeniería Mecánica

Abstract

The high levels of world contamination produced mostly by the burning of fossil fuels, have motivated the development of energies; therefore the design and construction of a solar cylindrical parabolic heater were carried out with investigation purposes for the Mechanical Engineering School. The present work is intended to be a starting point for the future investigations within the area. For the design and construction, investigations by authors were analyzed mentioning that there are three main elements which are: the absorbing pipe, the solar reflector and the follow-up system. The method of analysis of alternatives was used to choose the most adequate materials for each element. The first one is formed by two concentric pipes, the internal absorbs heat and the external one allows the light pass and avoids the convection losses. This pipe was placed in the focal point of the parable where it receives the solar rays from the reflector, which must have a high reflectivity index. The follow-up system must maintain perpendicular the heater as to the sun. The solar heater heats up to approximately 70 °C, in seven minutes when there is the higher radiation index, the approximate capacity being 40 liters of hot water a day. The heating system mathematical modelling was carried out in which a temperature gradient was obtained in the longitudinal sense, without considering the thermal distribution in the effective area of the system because of calculus facilities. Finally, the water heating was analyzed at different speeds. It was obtained that at a lower speed there is an increase in the temperature. It is recommended to clean the reflector so as to not to lose the efficiency in the heater, and carry out the modelling in the radial sense, and analyze new materials with better properties.