RT Journal Article ID 524e5f482cc3850d A1 Kim, Nae-Hyun T1 CONDENSATION HEAT TRANSFER AND PRESSURE DROP OF R-410A IN INTERNALLY ENHANCED FLAT ALUMINUM MULTI-PORT TUBES JF Journal of Enhanced Heat Transfer JO JEH(T) YR 2015 FD 2016-11-30 VO 22 IS 6 SP 503 OP 526 K1 extended surface K1 two-phase flow K1 small hydraulic diameter K1 micro- fins K1 grooved surface AB Brazed heat exchangers with aluminum multi-port tubes are being used as condensers of residential air conditioners. In this study, R-410A condensation tests were conducted in internally enhanced multi-port tubes. The enhancement consisted of grooves or micro-fins. The present grooved tube had two high micro-fins on the top and bottom of the channel, whereas the micro-finned tube had eight low micro-fins along the channel periphery. Smooth multi-port tubes of approximately the same hydraulic diameter were also tested for comparison purpose. The test range covered the mass flux from 100 to 400 kg/m2 s and the heat flux was fixed at 3 kW/m2, which are typical operating conditions of a residential air conditioner. The saturation temperature was 45° C. Heat transfer was enhanced by grooves or micro-fins, with significant amount in a micro-finned tube. The enhancement increased as mass flux decreased. The pressure drop also increased in grooved or micro-finned tubes. The pressure drop penalty decreased as mass flux decreased. The micro-fin effect on condensation heat transfer increased as vapor quality increased by exposing more fin area into vapor. The effect was more significant for micro-finned tube due to more fins. Data are compared with existing correlations. PB Begell House LK https://www.dl.begellhouse.com/journals/4c8f5faa331b09ea,31ae76120c8e1edd,524e5f482cc3850d.html