This article provides data on enhanced tubes developed especially for application to steam condensers. Data are provided for different types of tube-side (cooling water) and shell-side (steam) enhancements. The first test series involved measuring the condensing coefficient at a 327 K saturation temperature. Average enhancement levels (defined as the ratio of the condensing coefficient of an enhanced tube to that of a plain tube at the same vapor-to-wall temperature difference) of 34%, 75%, and 180% were obtained for titanium, copper-nickel, and copper, respectively. The second test series determined the overall heat transfer coefficient of several tubes having both internal and external enhancement geometries. Maximum enhancement levels of the overall heat transfer coefficient were 16%, 37%, and 64% (at the same mass flow rate for both the plain and enhanced tube) for titanium, stainless steel, and copper-nickel, respectively. A third data set was obtained for the tube-side heat transfer and pressure drop characteristics of several internal enhancements. Using specific combinations of the identified internal and external geometries, other potential enhanced tubes were defined, and a comparison of the overall heat transfer coefficient was made.
Journal description