CFD coupled heat and mass transfer simulation of pineapple drying process using mixed-mode solar dryers integrated with flat plate and finned collector

Abstract

The present research deals with the analysis of 3-dimensional computational models to analyze the airflow, temperature profile of dryer coupled with heat transfer of pineapple slices during solar drying. A finite element approach performed the simulations of mixed-mode solar dryers integrated with flat plate and finned collectors consisting of baffles and semicircular loops under forced convection using COMSOL Multiphysics software. The mass transfer of pineapple slices was also simulated to compare the moisture distribution inside the samples dried in both solar dryers. The dryer integrated with flat plate collector (FPSC) presented 2.5 h longer drying period than the finned collector assisted dryer to attain the 10% (wb) moisture of pineapples slices. The airflow pattern indicated inadequate air distribution inside the FPSC and generated two vortices contributing to dead zones and localized heating inside the drying chamber. The finned collector provided a more effective air distribution in the dryer. The sample's temperature was greatly affected by their position because of non-homogenous temperature distribution in FPSC-Dryer and finned collector integrated dryer presented more uniform temperature profile. The results are beneficial for the analysis of uniformity of airflow and temperature in the dryer, which is a deciding factor for homogeneity of drying.