EFFECT OF FIN EFFICIENCY ON A MODEL FOR CONDENSATION HEAT-TRANSFER ONA HORIZONTAL, INTEGRAL-FIN TUBE

A semi-empirical model for condensation on horizontal, integral-fin tu bes has been adapted to account for 'fin efficiency effects'. Specimen calculations have been made to investigate the effect of tube geometr y and material on the enhancement ratio for condensation of steam and CFC11. The best fin spacing was found to be only weakly dependent on t he other geometric variables and fin thermal conductivity. The best fi n thickness was more strongly dependent on fin thermal conductivity. F or the refrigerant the optimum fin thickness was smaller than presentl y used in practice. The model gave satisfactory agreement with experim ental data for CFC113 and steam for typical fin geometries. In the cas e of CFC113 the enhancement ratio was almost independent of fin therma l conductivity for conductivities exceeding around 50 W m-1 K-1.