Airside Performance of Fin-and-Tube Heat Exchangers Having Nonrepeating Nonsymmetrical Slit Fins under Wet Condition

Abstract

In this study, heat-transfer and friction characteristics of newly developed nonsymmetric slit-finned-tube heat exchangers are experimentally investigated. The newly developed slit fin had more slits in the second row than the first row. As a result, different row effect on [Formula: see text] factor than that of conventional enhanced finned-tube heat exchangers was observed. In other words, two-row configuration yielded larger [Formula: see text] factor than the one-row configuration. Comparison with conventional louver fin or slit fin heat exchangers revealed that the present slit fin heat exchangers show superior heat-transfer characteristics, especially at the second row. The reason was attributed to the many narrow slits that formed at the second row, which maintain thin water film along the slits and smooth the condensate flow.