Performance of Double-Pass Storage Solar Air Heater Using Two Types of Porous Media and Fin Plate

Abstract

As a result of the climate changes occurring on the planet and the carbon emissions they cause, solar energy systems must be developed in order to achieve greater efficiency. This study examines the performance of double-pass solar air heaters (DPSAH) with and without porous media under forced convection. Two types of porous media, glass balls and river gravel, were tested. The results showed that double-pass solar air heater model DPSAHM-1, with porous media, achieved up to 91.5% thermal efficiency in summer, outperforming double-pass solar air heater model DPSAHM-2 by 5%–10%. These findings highlight the potential of porous media to improve heat transfer and efficiency in solar air heaters. Fins were added to both sides of the absorber in both models to increase the heat transfer area and enhance the coefficient. Experiments were conducted on both models during summer and winter, and the results were compared under the same conditions. Consequently, DPSAHM-1 proves more effective than DPSAHM-2 in forced airflow applications and is suitable for high-temperature applications, while DPSAHM-2 is more appropriate for other conditions.