Heat transfer analysis of Dielectric Totally Internally Reflecting Concentrators transmitting concentrated solar energy

摘要

In this work the analysis of radiative heat transfer in steady state for a DTIRC as secondary concentrator of a linear Fresnel Reflector is carried out. The Radiative Transfer Equation (RTE) is simplified by neglecting the black body intensity term inside the medium. This way, the Radiative Transfer Equation and the energy equation are decoupled. The numerical solution of the heat transfer problem is based on Thompson's technique in order to facilitate computations. The model predicts the thermal behaviour and the flux distributions for two case studies corresponding to two different DTIRCs. Our results show that higher temperature spots are located at the center of concentrators for both case studies. In one case a temperature range from 75 to 108.2 degrees C was obtained whereas for the other case a range from 39 to 54.1 degrees C was observed. In addition, high efficiencies for concentrators, 82.2% and 93.5%, were found in the study. Depending on the dielectric material and the geometry of the DTIRC, photovoltaic or photothermal applications can be recommended. (C) 2018 Elsevier Ltd. All rights reserved.