Recent progress on solar cabinet dryers for agricultural products equipped with energy storage using phase change materials

Abstract

Solar energy can be used directly and indirectly in thermal processes such as solar dryers. Solar dryers have a high potential to dry wet samples, especially agricultural products with advanced technologies. The thermal energy storage system is used in thermal systems to enhance performance and may reduce the amount of time or level of uncertainty among supply and demand processes. In this paper, several drying systems, especially cabinet types assisted with phase change material (PCM), were reviewed. Different technologies for thermal energy storage in materials such as sensible and latent heat which were used in solar drying systems were investigated. Reviewing the literature indicated that PCMs have been more focused on high latent and sensible heat. Thus, using them in cabinet dryers leads to significant improvement in the quality of the dried products. Overall, the thermal efficiency of the dryers and collectors with PCM will respectively increase about 2.98–39% and 15.6–62% compared to the system without PCM. Computational fluid dynamics (CFD) modeling of solar cabinet dryers with PCM was investigated in the present review. CFD method was applied to the solar drying system to predict the variations of temperature in the collector and dryer and achieved the optimized conditions for the system assisted with PCM. Employing other new technologies such as desiccant systems, recycling mechanisms, usage of nano-fluids and nanoparticles in the dryer, and PCM can improve the thermal performance of solar dryers.