Flow condensation in smooth and micro-fin tubes with HCFC-22, HFC-134a andHFC-410A refrigerants part I: Experimental results

A study of single-phase convection and flow condensation heat transfer in h orizontal copper tubes (8.81 mm inside diameter) was conducted using three refrigerants (HCFC-22, HFC-134a and HFC-410A). A smooth tube and three micr o-fin tubes (axial, helical and crosshatch enhancement) were examined. Loca l-mean flow condensation data were experimentally obtained. Experimental co nditions were selected to reflect typical operating conditions encountered in refrigeration and air-conditioning applications. All micro-fin tubes ill ustrated significant enhancement in single-phase convection and how condens ation. The cross-hatch enhancement performed particularly better in both si ngle-phase convection and flow condensation. For the three refrigerants inv estigated, the refrigerant type seemed to have little influence on the enha ncement mechanism of the micro-fin tubes examined. The experimental results are presented in Part I. Development of design equations is presented in P art II.