Experimental study of air circulation in solar drying cabinets: optimization with phase change materials

Abstract

The purpose of this master's thesis is to present an experimental investigation into the optimization of air circulation within a solar drying cabinet, with a particular focus on enhancing drying performance through the integration of turbulence generators and Phase Change Materials (PCMs). Experimental trials were conducted on a specially developed mixed-mode solar dryer at the Renewable Energy Research Center (CDER-URAER) in Ghardaïa, Algeria. Various configurations were tested, including a baseline, PCM-enhanced, and designs incorporating internal turbulence promoters. Compared to the baseline, the enhanced configurations reduced the drying time. The integration of hydrated calcium chloride as a PCM maintained a higher temperature compared to ambient during night hours. Analysis of drying kinetics revealed a substantial increase in effective moisture diffusivity. Economically, the optimized mixed-mode solar dryer demonstrated a remarkably short payback period and projected an acceptable annual savings, with the potential to nearly double over its 15-year lifespan.