Thermal and environmental analysis of Cucumis sativus drying in a mixed mode solar dryer with combined sensible and latent heat energy storage

Abstract

Abstract This study presents a thermodynamic analysis of a mixed-mode solar dryer incorporating both sensible and latent heat energy storage materials. Black pebbles were utilized for sensible heat storage, while Lauric acid was selected for latent heat storage. The integration of these energy storage materials significantly enhanced the thermodynamic performance of the dryer, achieving a peak energy efficiency of 14.2% and a 53% increase in average energy efficiency. Additionally, the inclusion of latent heat storage in the collector resulted in the highest recorded collector energy efficiency of 84.6%. Exergy analysis indicated a maximum exergy efficiency of 51.3%, with an average exergy efficiency of 34.3% for the dryer. The implementation of combined thermal energy storage led to a 50% reduction in drying time. Sustainability assessments demonstrated that integrating both sensible and latent heat storage improved energy utilization while minimizing losses, thereby enhancing the overall sustainability and productivity of the solar dryer.The environmental analysis estimated a CO₂ mitigation potential of 83.97 tonnes per year, with a corresponding carbon credit value of $419.85. The system exhibited a remarkably low energy payback period of 1.82 years when operated with both thermal energy storage materials. This research underscores the potential benefits of combining latent and sensible heat storage in solar drying applications, highlighting its contribution to sustainability and the environmental advantages of solar thermal systems.