Condensation Heat Transfer Coefficient at Vapour-Liquid Interface of Subcooled Flow Boiling in Vertical Narrow Rectangular Channel

High speed camera visualized subcooled flow boiling bubble condensation experiments at 5 000 fps were conducted. Combined with the theoretic analysis, and considering the effect of convective heat transfer and the thickness of thermal boundary layer on condensation heat transfer, the relationship between dimensionless bubble diameter β and interface condensation heat transfer Nusselt number Nu Compared with experimental results, the error of the prediction is ranged within ± 25%.