Modelagem matemática e simulação computacional do receptor de um sistema dish stirling, com proposições de modificações geométricas visando diminuir as perdas por transferência de calor

Abstract

This paper presents an evaluation of the Dish Stirling Trinum system, which is installed in the Unifei Heliothermic Energy Laboratory. This evaluation is performed using experimental analysis, mathematical modeling and computational simulation. At first, an experimental analysis is performed to obtain important data for the other stages of the evaluation. Then a mathematical modeling is developed with reference to the works of Caballero, 2013 and Castellanos, 2012, to evaluate the heat transfer losses that occur in the receiver of this system. The thermal losses are evaluated in two ways, the dynamic losses that occur during the operation of the system, and later also the thermal losses are evaluated for the different inclinations and wind speeds that the system can attain during its operation. In another stage of this evaluation, the computational simulation is used to evaluate the wind speed in the region of the cavity and in the surroundings of the receiver of the Trinum system, considering different inclinations and wind speeds. The computational simulation also evaluates the losses by radiation and convection based on the rates obtained for the receiver cavity. Based on the evaluations of the previous steps, ten different modification models for receiver geometry are proposed and evaluated that decrease the air velocity in the receiver cavity. Still using the computational simulation, the optical losses (Spillage losses) are evaluated for the actual receiver of the system and for the proposed models.