MECANISMOS DE MEJORA DE LA EFICIENCIA EN COLECTORES SOLARES TÉRMICOS MEDIANTE TÉCNICAS DE RUGOSIDAD ARTIFICIAL

Abstract

The improvement of thermal efficiency in solar thermal collectors can be reached by the use of materials able to reduce heat losses by conduction, convection and radiation into the environment. Another methodology consists of diminishing the thermal resistance between the environment and the heat transfer fluid. This can be achieved through the increase of convective heat transfer in the tube side using artificial roughness techniques. In this work, the potential of using twisted tapes in the parallel tubes of a solar thermal collector is explored in order to promote the enhancement of thermal efficiency, considering the increased demand of pumping power. A standard solar collector installation in a building is analysed and contrasted with an equivalent one with enhanced collectors. A discussion of the advantages about installed surface reduction is made as well as pumping power demanded by the system, economics and lower carbon dioxide emissions.