Performance of various solar dryer types integrating latent heat storage for drying agricultural products: An up-to-date review

Solar dryers are used to dry various agricultural products cleanly and cost-effectively. Their performance can be improved by integrating phase change materials (PCM) for thermal energy storage. This review paper aims to present an up-to-date review of research advancements made on solar dryer technology integrating PCM-based thermal energy storage and highlight future research directions. Experimental and numerical studies are examined and discussed to highlight the potential of PCM for enhancing solar dryer performance, including thermal efficiency and exergy, as well as other performance indicators, including the drying time, extension of the operating drying period, and economic aspects such as payback time. Different dryer types are examined, including direct, indirect, mixed, and hybrid dryers. The survey shows a significant performance enhancement of solar dryers by incorporation of PCM. Further improvement is obtained by the inclusion of nanoparticles and fins into PCM. Finally, research gaps are highlighted at the end of the study for future research, along with concluding points.