Modeling and Design of a Flat Plate Solar Collector with Closed Air Circulation for Drying Spices

The current work is confined to design and modeling of a flat plate solar collector for drying of spices. This paper highlights the collector design for drying of cardamom. Based on the cardamom moisture content, the collector dimensions are estimated. A single cover flat plate solar collector with selective coating and forced convection is designed with closed loop circulation of air. Using energy balance equations, the theoretical model of the collector is developed. The collector dimensions are found to be 2.1m2 from simulation for 10 kg of cardamom. The maximum temperature obtained at the absorber surface is 68 °C and the temperature of air at the collector output is 55 °C which is safe for cardamom drying. The analysis of variation of collector outlet temperature and efficiency with respect to solar irradiance are done and presented.