Enhancement of Condensation on a Vertical Plate (1st Report, Heat Transfer Characteristic on a Dispersed Finned Surface)

Abstract

In this study, a condensation heat transfer experiment on vertical continued and dispersed finned surfaces using FC 5312 was carried out. Experimental parameters were the pitch and height of the fin, and the dispersed fin length. As the results, the phenomena of condensate retention were observed in the bottom of each row of the dispersed fin. The condensate flow from the upper row was concentrated into the valley of the fin and then flew down into the valley of next fin. Moreover, it was found from the experiment that the heat transfer coefficient on the dispersed finned surface was lower than the one on the continued finned surface as the fin pitch was smaller, but was larger than the one on the continued finned surface for the larger fin pitch. Further, the heat transfer enhancing effect become more significant for the higher fin with the larger fin pitch, and the heat transfer reducing effect become more significant for the lower fin with the smaller fin pitch. These special characteristics of condensation mentioned above were caused by the phenomena of condensate retention in each row of the fin and the flow pattern of the condensate between two adjacent fins on the dispersed finned surface based on experimental observations.