Abstract
The drying of agricultural products constitutes a particularly voracious field in energy, which encourages us to reflect on the more rational use of the resources available and especially the use of renewable energies like solar energy. The objective of this work, based on a theoretical and experimental study, is to investigate, the performance of two designed components of a drying solar unit (collector and storage system) without drying energy supplement. So, to satisfy a dimensioning already carried out on a macroscopic scale for an energy request well defined: to dry a quantity of a given agricultural products during one day of harvest season, so between September and May, with a heat storage which relays at night. The mathematical formulation of the physical process of each element, based on conventional heat equations, show a certain agreement with the experimental results under fixed conditions of drying. Experimental results show that the efficiency of the solar collector at flow rate of 0.014 kg s(-1) is 30.52% and the difference in temperature created by the storage system is about 10 degrees C with an efficiency more than 60% and 90% respectively during charging and discharging phase. (C) 2014 Elsevier Ltd. All rights reserved.