Experimental and numerical study of tomato dryer using a phase change material assisted solar dryer in Al-Baha (Kingdom of Saudi Arabia)

Production of fruits and vegetables serves a crucial role in human nutrition, and provides essential nutrients such as fiber, vitamins, proteins, and minerals. However, their seasonal nature necessitates effective preservation methods, with drying being among the most efficient techniques. Solar drying, known for its affordability and eco-friendliness, faces limitations like inconsistent solar radiation and slow drying processes. This study investigates the drying process of tomatoes under the arid conditions of Al-Baha, Saudi Arabia, utilizing a solar dryer enhanced using paraffin wax as a thermal energy storage phase change material (PCM). Two configurations were evaluated: an indirect solar drying system (Mode 1) and a mixed solar dryer incorporating PCM (Mode 2). The results indicated that the inclusion of PCM reduced drying time from 10 h in Mode 1 to just 7 h in Mode 2, while also improving thermal stability and system efficiency. In addition numerical analysis was done to compare the results with the actual experimental outcomes for verification. The numerical and experimental results comparison shows that the incorporation of PCM has enhanced and stabilized the temperature in the dryer, especially during low solar radiation hours. Both methods show a similar trend overall, confirming the heat retention property of PCM and indicating that the numerical model is reliable in predicting the thermal behavior of the solar dryer. Beyond agricultural preservation, this research highlights the broader potential of PCM-integrated solar drying systems as a solution for thermal energy storage, particularly in energy-scarce and arid regions. These results provide valuable insights into promoting sustainable agricultural practices and advancing global energy storage technologies.