Thermal energy storage systems applied to solar dryers: Classification, performance, and numerical modeling: An updated review

Drying is a complex process involving simultaneous heat and mass exchanges, and it is considered one of the oldest unit operations performed for preserving agricultural products. This process requires a significant amount of energy, and researchers have conducted different studies to improve energy efficiency, reduce drying time and preserve product quality. Dryers based on solar energy have gained more space, as this energy source is free and abundant. Thermal energy storage techniques can increase the reliability of solar energy for drying. These techniques allow the stored energy to be used in periods of no solar incidence. The complex processes involving each element of the solar drying process have made experiments quite expensive. Several studies have bet on the use of advanced techniques of computer simulation to minimize this problem. Studies have shown the effectiveness of using these techniques for different solar dryers, achieving satisfactory results. Therefore, this study aims to provide parameters, address different types of dryers, and emphasize the importance and methods of thermal energy storage. In addition, this study also addresses the use of computational numerical modeling to verify the phenomena of heat and mass transfer in drying systems and thermal energy storage.