Numerical simulation of conjugate heat transfer in a PTC with secondary reflector

Abstract

This paper presents a numerical simulation of the conjugate heat transfer and fluid flow in the tube absorber of a parabolic trough collector (PTC). The main objective is to analyze the system performance with and without a secondary reflector. The PTC is tested under climatic conditions present in Laghouat city (ALGERIA). PVSYST software is used to provide numerical temporal values of the solar heat flux in Laghouat region. Daily heat flux values for four days in different seasons have been taken. The non-uniform heat flux distribution on the absorber tube is calculated by using Monte Carlo ray tracing method in SolTrace software. The governing equations of fluid flow and heat transfer in the system are solved by using ANSYS-CFX CFD software. A comparison between two cases (with and without second reflector) with the same working fluid (Therminol VP-1) is carried out. The obtained results show that the maximum fluid temperatures are reached during the month of June while the minimum values are obtained on the month of December. However, the system performance is practically the same for the four seasons. Moreover, the performance of the system with a secondary collector is better than that without a secondary reflector with a ratio of about 3/2.