Effect of Fin Height on Film Condensation of Steam on Stainless Steel Integral-Fin Tubes

摘要

Condensation heat transfer performance on a series of horizontal stainless-steelintegral-fin tubes was experimentally studied at both atmospheric and vacuum pressure conditions to examine the effects of fin height on tubes of low thermal conductivity. Eight tubes with rectangular fin heights ranging from 0.16 to 1.42 mm and a smooth tube were tested. The fin thickness and spacing and tube inside and root diameters were kept constant at 1.0, 1.5, 13.1, and 14.2 mm respectively. The overall heat transfer coefficient was determined from experimentation and the outside heat transfer coefficient was then determined using the modified Wilson plot technique. A fin height of approximately 0.30 mm provided the maximum heat transfer at both vacuum and atmospheric conditions. Heat transfer performance declined steadily for further increases in fin height. The experimental results were compared to the predictions of the Beatty and Katz and Briggs and Rose models. Neither model satisfactorily predicted performance for the full range of fin heights tested. (AN).