Exergetic optimization of simple and finned solar air collectors for humid subtropical regions.

Abstract

In this paper, an exergetic optimization of simple and finned flat plate solar air collectors is established to determine the optimal design and operational parameters for humid subtropical climatic conditions. Solar air collectors are commonly used for space heating, irrigation, greenhouses, grain drying, hot air generation, etc. A detailed solar energy radiation model is developed for solar energy conversion. A comprehensive optical, energy, and exergy analysis is carried out for evaluating the performance, energy and exergetic efficiency for simple and finned flat plate solar air collectors under humid subtropical climatic conditions. A simulation program is developed for solar energy model, energy and exergetic calculations. The following geometric and operating parameters are considered as decision variables: absorber plate area, dimensions of simple and finned solar collectors, fluid inlet and outlet temperatures, average velocity, overall loss coefficient, glass cover temperatures, plate temperature, and useful heat gain. The proposed model is optimized using computational intelligence technique (single phase multi-group teaching learning optimization) for maximum mean exergy efficiency in simple and finned solar air collectors for humid subtropical regions. The maximum exergy efficiency is achieved in the case of finned solar air collectors with a yearly optimal average exergy efficiency of 6.10% for a collector area of 5 m2 and a yearly average heat flux of 601W/m2. Thus, beneficial applications of exergetic optimization in design and operation of solar collectors for humid subtropical climatic conditions based on maximum exergy efficiency according to the optimized parameters and benefits of this approach for such systems have been highlighted.