Performance analysis of a forced indirect cabinet solar dryer for drying figs

In the solar drying process, a lower air velocity is unable to rapidly extract moisture from the products to the outside, while a higher air velocity has a negative effect. To improve the final quality of the dried products, the effect of air inlet velocity (0.1, 0.3, and 0.5 m/s), air outlet position, and inlet size of an indirect solar dryer operating in forced convection was studied. The Computational Fluid Dynamics (CFD) method, validated by experimental results, was used for this investigation while the meteorological data used to define the boundary conditions are exported from the meteorological station. The obtained results show that the average temperature of tray 1 reaches 314, 311.75, and 311 K for the right, middle, and left outlet positions, respectively, with an inlet velocity of 0.1 m/s. In addition, the average collector outlet temperature is higher (329 K) for the 0.05 m inlet size. The trays temperature peaks at 2 pm on the selected day, with an average temperature of 326 and 324 for trays 1 and 2, respectively. Based on the current results, the farmers will have a good insight into the parameters for the realisation of a solar dryer. © 2023 Informa UK Limited, trading as Taylor & Francis Group.