Experimental and computational validation of thermal performance of an active greenhouse solar dryer in no-load conditions

This study focused on developing a finite element (FE) model using COMSOL Multiphysics to simulate the active mode of a greenhouse dryer under no-load conditions in Ranchi humid subtropical climate. The model visualized the temperature and humidity distribution within the dryer and was validated against real-world experimental results. Under unloaded conditions, the performance assessment revealed a 29.14% efficiency for the proposed dryer and a maximum overall convective heat transfer coefficient of 5.0 W/m^{2 ◦}C. The internal temperature ranged from 50^◦C to 70^◦C, while the relative humidity hovered between 30% and 45%. The COMSOL Multiphysics-based FE model demonstrated close agreement between experimental and predicted results, with minimal statistical error. Overall, the findings suggest that the active mode of the greenhouse dryer could be a valuable tool for crop drying in humid subtropical climates. Additionally, the FE model presents a promising approach for future research and development.