Abstract :
A mathematical model for drying agricultural products in a mixed-mode natural convection solar crop dryer (MNCSCD) using a
single-pass double-duct solar air-heater (SPDDSAH) is presented. The model was developed in parallel with experimental work. The
model comprises the air-heating process model, the drying model and the technical performance criteria model. The governing equations
of the drying air temperature and humidity ratio; the material temperature and its moisture content; and performance criteria indicators
are derived. The model requires the solution of a number of interrelated non-linear equations and a set of simultaneous differential equations.
Results from experimental studies used for generating the required experimental data for validating the model are presented.
Results of simulation runs using the model are presented and compared with the experimental data. It is shown that the model can predict
the performance of the MNCSCD fairly accurately and therefore can be used as a design tool for prototype development.
2006 Elsevier Ltd. All rights reserved
