Performance of an integrated array of solar collector modules for different air flow rates and flow organizations

Abstract

A 20 m 2 integrated flat plate solar air heating module has been developed at IIT, Kharagpur, India to match with a grain dryer of capacity 0.5 t paddy/day. Based on some statistical, physical and operational parameters, an iterative procedure has been followed for designing this integrated array system. It consists of 10 small collectors (2 × 5) with a number of common partitions among themselves. Under identical conditions, any compartment of the integrated array of collectors shows higher thermal efficiency and temperature rise of air compared to that for any exactly similar small collector whose four side edges are directly exposed to the outside environment. The temperature rise and efficiency of the system vary nonlinearly with both air flow rate and collector area. A second degree multiple regression equation has been developed for the present system relating temperature rise to air flow rate and collector area. The performance of the integrated array system also varies with air flow organization. Combined flow organization gives the best performance followed by parallel and series flow organizations. The results of the iterative procedure have been compared with some observed parameters.