BT-42 Improved heat transfer methods for tubeside falling film evaporators

L. Huang

HTRI collected falling film evaporation data for two pure components and three mixtures in a vertical tube. Current falling film methods in Xist® 8.2 underpredict most of the measured heat transfer coefficients. Based on the latest data, we have improved our heat transfer methods, including a vapor-shear enhancement factor, a new mixture correction factor for our convective boiling method, a correlation for predicting the required wall superheat for the onset of nucleate boiling, a method for applying a nucleate boiling contribution, and a correlation for liquid sensible heating for a subcooled liquid film.