| Summary: | The most promising collector must achieve the best thermal efficiency and fill out high requirements of low weight, low power consumption, ease of manufacturing, and low cost. In this study; a novel efficiently optimized flat plate solar air collector is modeled with a selective absorber and three rows of rectangular fins installed beneath the structure that provides 81% of thermal efficiency and 0.5 W of pumping power. A three dimensional CFD model of a flat plate solar air collector is developed and solved in steady-state conditions. We propose a suitable approach for assessing and optimizing a 1.28 m2 surface collector’s performance with forced convection flow. Results indicate that additional fin rows (from 35 rows to 142 rows) and fins relative height (0.5 to 0.8) with a nonselective absorber increase the thermal performance from 63% to 80%, and additional turbulent flow causes an increase of pump power from 1.8 W to 16 W. The adoption of a selective absorber contributes to efficiency 5% higher than that of a collector with 35 rows of fin for a volume flow of 85.33 m3/hm2. In contrast, the gain achieved by adding 142 rows of fin (l’/L=0.006) remains the most important, where it leads to an effective efficiency of 79.2% for a volume flow rate of 85.33 m3/hm2. Thus, it has been proposed to combine the selective absorber with the addition of rectangular fins in the new design.
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