Experimental Study of Countercurrent Steam Condensation

An experimental study of steam condensation on subcooled liquid films in countercurrent flow has been conducted in a small inclined test apparatus having a rectangular cross-section. Condensation heat transfer coefficients were determined and the dependence on steam and water flow rates, the degree of subcooling, and test section inclination were all studied. The results were correlated in terms of local parameters for the complete penetration and bypass regions. It was found that the local Nusselt number increases with steam and liquid Reynolds numbers and liquid Prandtl number when no bypass occurs. In the bypass region the Nusselt number drops sharply due to the strong effects of the reduced liquid film flow rate. It is shown that the local heat transfer coefficient may be related to the turbulence intensity in the liquid film which suggests that a general turbulence-centered model can be constructed.