A novel energy, exergy and sustainability analysis of a decentralized solar air heater integrated with V-shaped artificial roughness for solar thermal application

Alternative energy sources are in high demand at the present time because of the changing climate and rising energy usage. The decentralized solar air heater is an eco-friendly, cost-effective, and sustainable heat exchanger that may be used to generate heat for a variety of purposes, including decentralized building heating, industrial heating, and agricultural drying. This work used a combination of analytical and computational fluid dynamics (CFD) techniques to investigate the thermohydraulic performance (THPP) of a solar air heater integrated with Vshaped ribs. The analysis results were compared with those of a smooth absorber plate, with particular attention paid to exergy (eta ex), and thermal efficiency. The absorber including V-shaped ribs exhibited a notably greater thermal efficiency (eta th) in contrast to the smooth duct. Remarkably, the thermal efficiency (eta th) of the V-ribbed absorber was 40 % higher than that of the smooth duct, and its Nusselt number was five times higher. Additionally, a new sustainability rating for solar air heaters based on energy and potential improvement measures is suggested by our investigation. The optimum ratios for achieving the most effective thermal performance were found to be (W/w) = 6, P/e = 8, (e/D) = 0.043, and (alpha/90) = 0.66.