An analytical investigation on the role of non-condensable gases (NCG) during condensation of steam outside vertical tubes, in a seawater desalination multiple-effect plant was carried out. The heat and mass transfer process for a single tube was described, using a two-phase boundary layer model of Minkowycz together with an evaporation heat transfer model inside the tube. Heat transfer coefficients and condensate (product) flow rates were obtained as a function of the NCG concentration. Based on this, a picture of the NCG concentration distribution was computed for a tube-bundle of a single effect. The influence of this distribution on the heat transfer coefficient along system tubes was also examined. The model was implemented in an iterative algorithm and a computer code.

Publication:

Semiat R. and Galperin, Y., "Effect of Non-Condensable Gases on Heat Transfer In The MWD Sea Water Distillation Plant", Submitted to publication.