Parametric study of a solar air heater with and without thermal storage for solar drying applications

摘要

A transient analytical model is presented for a falt-plate solar air heater with and without thermal storage. The flowing air temperature is assumed to vary with time and space coordinates. Analytical experessions are obtained for various temperatures of the air heater elements as well as for the temperatrue of the storage material. Teh performance of the air heater is investigated by computer simulation using the climateic conditions of Tanta (Lat. 30 deg 47'N, Egypt). Effects of design parameters of the air hater such as length (L), width (b), gap spacign between teh absorber plate and glass cover (d_f), mass flow rate (m) and thickness and tupe of the storage material (sand, granite and water) on the outlet and average temperatures of the flowing air are studied.