| The objective of this research is to identify enhanced surfaces for horizontal steam condensers. Experimental and theoretical approaches were utilized to achieve a solution to the issue. Although the research was directed at electric utility steam condensers, the results are applicable to other industrial sectors that involve steam condensation. Three commercial tube manufacturers provided six specially made enhanced tubes for testing. The measured condensation heat transfer coefficient at 54 C saturation temperature was compared to that of a plain tube to determine the enhancement level. The tubes had different fin size, shape, spacing, and thermal conductivity. The fin height varied between 0.28 mm and 1.12 mm, and the fin distribution varied from 453 fins/meter to 748 fins/meter. The tube outside diameter varied from 18.29 mm to 22.23 mm. The experimental results show that the condensation heat transfer coefficient was enhanced by 34%, 75%, and 280% for titanium, copper nickel, and copper tubes, respectively. A theoretical model was developed to solve the conjugate heat transfer problem between the condensing fluid and the cooling water. The model was justified by predicting data of other investigators for steam and refrigerants. The condensing coefficient was predicted within ;One titanium tube and one copper-nickel tube were tested at a saturation temperature of 42 C to determine the overall heat transfer coefficient. At 2.0 m/sec (6.5 ft/sec) water velocity, the overall heat transfer coefficient was enhanced by 21% and 80% for the titanium and copper-nickel tubes, respectively. The estimated water side enhancement was 10% and 80% for the titanium and copper-nickel tubes, respectively. |
