Exergy analysis of solar heat collector with air jet impingement on dimple-shape-roughened absorber surface

Abstract

Abstract The indented dimple-roughened jet impingement solar heat collector (CJISHC) performs better thermally and is more cost-effective than conventional single-pass solar heat collectors (SPSHCs) under the same operating conditions. However, due to the presence of jet impingement and dimple roughness, pumping power is required to obtain the appropriate airflow, resulting in a higher friction loss. The exergy analysis based on the second law of thermodynamics is appropriate for designing CJISHCs because the efficiency of useable energy production as well as pumping power are considered. The effects of the Reynolds number (Re), arc angle (αd), indented dimple height ratio (e/Dh), and indented dimple pitch ratio (p/Dh) with the ranges of 3000–21\u2009000, 30°–75°, 0.016–0.027, and 0.27–0.81, respectively, between the dimples on the exergetic efficiency of a CJISHC were studied considering examined flow and roughness parameters. In addition, a cost-effectiveness analysis was performed to examine the cost-benefit ratios of the CJISHC and conventional SPSHC. The results showed that the CJISHC is more cost-effective in the m ˙ a range of 0.01–0.07\xa0kg/s. Moreover, the exergy analysis revealed that at optimal dimple roughness values, viz. αd\xa0=\xa060°, e/Dh\xa0=\xa00.027, and p/Dh\xa0=\xa00.27, which depicts the maximum value of ηexe\xa0=\xa00.026\xa0at temperature rise parameter, TRP\xa0=\xa00.03\xa0Km2/W.