Numerical Study of a Longitudinal Solar Dryer in Semi-Arid Area; Case Study

Abstract

A numerical simulation to predict the thermal performance of a longitudinal solar dryer has been carried out. For this, a mathematical model, based on the finite element method, has been developed to evaluate the thermal behavior of the solar dryer using a control system. The main objective of the used control system is to maintain the drying temperature inside a suitable range for the product to dry, under varying weather conditions, over the time drying process. This is achieved through many different steps. As, an example, at the beginning of drying process when solar radiation is low, the air flow rate at the inlet varies between Re=25 and Re=85. In other hand, when solar radiation is higher, fresh air is injected. The outcomes of simulation work showed that the obtained results are generally satisfactory. Nonetheless, this model can be further refined to obtain better results, as a more stable gradient temperature, over the full drying period. Moreover, it is worthy mentioned that thermal storage system can be combined with the studied solar drier, in the way to compensate the heat insufficiency, during low solar radiation day