BT-43 Liquid Film Breakdown in Tubeside Falling Film Evaporators

L. Huang

2021

This report provides an overview of several mechanisms for the breakdown of falling film. Available literature and HTRI data enable confirmation of the minimum wetting flow rate calculation used in Xist 8.2 and the development of two correlations for determining Reynolds numbers for the Marangoni breakdown, one for the subcooled zone and another for evaporation. The report also includes recommendations for checking potential dry-wall conditions due to a high heat flux or a high weight fraction vapor. Finally, it sets forth an upper limit for the inlet liquid flow rate to prevent tube flooding.