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A model was established to predict condensation heat transfer coefficient on horizontal rectangular-finned tube. Drop-Off zone at the tube bottom was considered and determined, the known Honda(and owen) expression of retention angle was also modified as a result of considering drop-off zone.Heat flux on fin tips in the unflooded region, fin fianks, fin spacings and fin tips in the flooded regionwere analyzed respectively. Condensation on fin tips is emphasized by considering the variation of filmthickness along circumference as well as horizootally. Fin efficiency was considered in calculation. Theprediction results were compared with several researchers’ experimental data for three kinds of workingfluids on seven different tube geometries and for various temperature differences. These data underabout 60 test conditions were predicted with discrepancy of ±10%. Prediction by the present modelfor steam and R-113 condensation were compared with previous models.
A model was established to predict condensation heat transfer coefficient on horizontal rectangular-finned tube. Drop-Off zone at the tube bottom was considered and determined, the known Honda (and owen) expression of retention angle was also modified as a result of considering drop -off zone.Heat flux on fin tips in the unflooded region, fin fianks, fin spacings and fin tips in the flooded regionwere analyzed respectively. Condensation on fin tips is emphasized by considering the variation of filmthickness along circumference as well as horizootally. Fin efficiency was considered in calculation. Theprediction results were compared with several researchers’ experimental data for three kinds of working fluids on seven different tube geometries and for various temperature differences. These data underabout 60 test conditions were predicted with discrepancy of ± 10%. Prediction by the present modelfor steam and R-113 condensation were compared with previous models.