摘要

A study of single-phase convection and flow condensation heat transfer in horizontal copper tubes (8.81 mm inside diameter) was conducted using three refrigerants (HCFC-22, HFC-134a and HFC-410A). A smooth tube and three micro-fin tubes (axial, helical and Crosshatch enhancement) were examined. Local-mean flow condensation data were experimentally obtained. Experimental conditions were selected to reflect typical operating conditions encountered in refrigeration and air-conditioning applications. All micro-fin tubes illustrated significant enhancement in single-phase convection and flow condensation. The cross-hatch enhancement performed particularly better in both single-phase convection and flow condensation. For the three refrigerants investigated, the refrigerant type seemed to have little influence on the enhancement mechanism of the micro-fin tubes examined. The experimental results are presented in Part I. Development of design equations is presented in Part II.