Enhancing Solar Drying Efficiency Through Indirect Solar Dryers Integrated with Phase Change Materials

Since time immemorial, solar radiation has been harnessed for drying a myriad of products such as vegetables, fruits, fish, and meat, primarily through direct exposure to sunlight for moisture removal and desiccation.In recent years, the incorporation of Thermal Energy Storage (TES) systems, capable of storing thermal energy in various states, has emerged as a pivotal innovation for enhancing energy efficiency and utilization.This study elucidates the development and performance evaluation of an indirect-mode solar dryer, augmented with Phase Change Materials (PCMs) for food dehydration.The solar dryer, operating in an indirect mode, channels solar radiation as the heat source from the collector's inlet, directly linked to the drying chamber.Within this setup, potato slices were subjected to dehydration under controlled conditions.The peak temperature recorded in the dryer was 63℃, with the relative humidity plummeting to 40%.Initial moisture content of the potato slices was determined to be 78.58%(w.t).The experimentation, involving a 1kg sample, revealed a marked improvement in drying efficiency with the integration of PCMs.The sample attained the target moisture content of 10% (w.t) in a span of 24 hours with PCM, compared to 33 hours in its absence.Conventional sun drying methods, without any enhancements, necessitated 38 hours for reducing the moisture content to the same level.Notably, the application of a single container of PCM resulted in a 3.26% reduction in heat flux, while the utilization of two different types of wax as PCMs yielded a 2.24% reduction.These findings underscore the significant role of PCMs in optimizing the thermal performance of solar dryers, promising substantial advancements in the field of solar drying technologies.