Thermal modeling of a parabolic trough collector in a quasi-steady state regime

Abstract

This manuscript deals with a quasi-steady regime thermal analysis of a solar parabolic trough collector in the climatic conditions of the city of N'Djamena located in a Sahelian region of the Chad Republic. The objective is to develop the solar electricity potential of N'Djamena and contribute to the development of renewable energies in the country. A one-dimensional numerical model was developed in a quasi-steady regime to simulate and analyze the thermal behavior of the system. The energy balance equations governing the thermal behavior of the collector are solved by the implicit finite difference method, while considering the variation of the solar radiation over time. Initially, the model was validated by experimental data existing in the literature. Excellent agreement is observed when comparing the numerical results to experimental data. The effect of various parameters, including the type of heat transfer fluids, wind speed, and mass flow rate of fluid, on the thermal performance of the parabolic trough solar collector in quasi-steady regime operation was observed. It is shown that the variation of wind speed has a very slight effect on the thermal performance of the collector. Four fluids (therminol 66, therminolV-P1, untreated water, and treated water) were simulated between 11:00 and 15:00 local time. Through the simulation of four fluids, it was shown that the energy efficiency of the collector when using oil is much better than with water.