Contribution à l’amélioration des performances thermique d’un convertisseur thermo solaire destiné pour le séchage

Abstract

This thesis presents a numerical and experimental study of a flat air solar collector intended for solar drying. The first part focuses on a numerical analysis of a laminar airflow with forced convection. Simulations were carried out to determine and analyze the dynamic and thermal fields of different configurations of collector. Two cases of solar collector geometry “with a narrowing at the exit and with a widening at the entrance” were studied and compared to a uniform solar collector, based on the variations of temperature and velocity at the exit. The study revealed that the improvement in heat transfer can be achieved by using a zigzag shape for the absorber and from the dynamic point of view, the exit velocity of the shrinkage pattern of the pass section at the exit of the collector can be increased by up to 250% over the input velocity, which ensures a strong flow at the drying chamber. The second part of this thesis aims at an experimental study on a solar collector intended for drying. A new model of collector comprising an absorber made by used aluminum can pipes and fitted with fins inside was producedand studied in the mechanical laboratory at the University of Ain Temouchent. The effect of the number of rows of cans was also treated and compared with a simple absorber collector, based on the variation of the outlet temperature and the thermal efficiency. The study showed that a 14-row collector has an outlet temperature difference of 24°C compared to the single collector and an efficiency of 54%.