Local heat transfer coefficient of steam condensation with high fractional noncondensable gas in the dewvaporation desalination process

Abstract

A tubular condenser column was designed and constructed to evaluate the performances of the condensation process with a high fractional noncondensable gas in the dewvaporation desalination process. An experimental investigation has been conducted to determine the local condensation heat transfer coefficient, which is related to steam-air mixed gas condensation in an annulus around a vertical copper tube. The results show that the local heat transfer coefficient decreases with increase of the distance from the mixed gas inlet, and varies from 200 to 1900 W/m(2).degrees C, which is high enough for steam condensation in the presence of a high fractional noncondensable gas. The correlation of steam condensing local heat transfer coefficient in the presence of a high fractional noncondensable gas was developed in terms of the local mixture Reynolds number, Jakob number, and ratio of noncondensable gas mass fraction. It is found that the correlation has a good agreement with the experimental data.