Abstract
On the general heat exchanger of a vertical circular tube, cooling water is run from the bottom to the top in the tube. However, according to the last research of the dropwise condensation of authors, it is anticipated that the good heat transfer characteristic is obtained when the cooling water is run from the top to the bottom. Heat transfer characteristic on a vertical condensing circular tube was obtained by using a copper tube (o.d.40mm, i.d. 30mm and length 700mm). When the cooling water in the tube flew down and up, the heat transfer had a good characteristic in the case of water flowing down. And we evaluated the relation between the behavior of condensate drops and the heat transfer, and then, the sweeping action had a significant effect in this experimental conditions.
