Experimental investigation and exergy analysis of an air heater with a solar concentrator used for drying processes

Abstract

In this paper, a solar air heater collector is developed and investigated. A concentrating feature of Linear Fresnel Reflector and the characteristics of flat plate air heaters (LFRAH) collectors are used. In this experimental study, three configurations of the absorber used to improve the thermal performance of LFRAH for the drying and the space heating processes, where two configurations of the absorber plate have different types of artificial roughness and the third configuration has a smooth absorber. The measured parameters are the ambient temperature, inlet and outlet temperatures of the air heater, the temperatures of the absorber, and the solar radiation intensity. The measurements performed at the same values of mass flow rate, 0.018 (kg.s -1 ). The introduction of the artificial roughness at the absorber plate allows having average air temperatures greater than 100° C. The comparison of the thermal efficiency shows that the roughened absorbers improve the thermal efficiency by 62% compared to the smooth absorber.