BX-11 The Onset of Nucleate Boiling on the Shell Side of Plain Tube Bundles
HTRI recently studied the onset of nucleate boiling (ONB) on the shell side of two ideal plain tube bundles using pure hydrocarbons and hydrocarbon mixtures. The data indicate that the wall superheat required for ONB is higher at low pressures and about twice as high for mixtures as for pure components. Based on these data, we propose an improved ONB model with a mixture correction factor that accounts for increased required wall superheats for nucleate boiling incipience. Our model can assist heat exchanger designers to determine whether shellside nucleate boiling is sustainable with a given wall superheat.