Publicado 8 números por año
ISSN Imprimir: 1065-5131
ISSN En Línea: 1563-5074
Indexed in
CONDENSATION HEAT TRANSFER AND PRESSURE DROP OF R-410A IN INTERNALLY ENHANCED FLAT ALUMINUM MULTI-PORT TUBES
SINOPSIS
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.