Design, Construction and CFD Modeling of a Banana-Solar Dryer With Double Pass Solar Air Collector

A work on the design, construction and computational fluid dynamics modelling of a solar dryer with a double pass solar air collector is presented. Using fundamental relationships, an indirect solar dying system for drying banana was designed and constructed. The system consists of a drying chamber and a double pass solar collector (DPSC), connected together with a flexible aluminum pipe. The system features a unique arrangement, as the drying chamber is underneath the double pass solar collector, and the solar collector itself can be adjusted to an angle of 0° up to 35° the maintenance or research purpose. The DPSC has five longitudinal fins, lying parallel with air flow. The solar dryer is incorporated with a convective DC fan that sucks hot air from the solar collector on to the drying chamber. The DPSC achieved an optimal peak outlet temperature of 345K with a maximum operational efficiency of 72.5%. A computational fluid dynamic (CFD) model is achieved for prediction of the dryer temperature and 3D airflow distribution within the dryer unit using ANSYS 18.2. The CFD model was validated using experimental data. The developed dryer demonstrated improved efficiency over similar dryers, and this is attributable to the unique arrangement of component parts.