Investigations on the Condensation Heat Transfer Performance of Stainless Steel Edge Shaped Finned Tubes

Abstract

The thirdgeneration enhanced heat transfer technologies, such as threedimensional fin and dimple, are still important means of improving energy efficiency. This paper analyzes the condensation heat transfer performances of three edgeshaped finned tubes that were fabricated using the plowing–extruding process. Experimental results show that the shellside heat transfer coefficient decreases with increases of heat flux and temperature difference between wall and vapor. The edgeshaped finned tubes exhibit better heat transfer performance than smooth tubes. At the identical temperature difference between the wall and the vapor, the shellside heat transfer coefficient of the edgeshaped finned tubes is approximately 1.7–2.6 times larger than that of the smooth tubes. At the identical temperature difference between the wall and the vapor, the shellside heat transfer coefficient of edgeshaped finned tubes is also higher than the reported value in the literature. The excellent performance of the edgeshaped finned tubes comes from the coordination of enhancement from the threedimensional fins, dimples, and grooves. Finned tubes with grooves fabricated along the left direction have higher and thinner fins and therefore show better heat transfer performance. The shellside heat transfer coefficients of edgeshaped finned tubes increase with plowing–extruding depth and feed increasing.