Effect of submergence on boiling incipience in a vertical thermosiphon reboiler

An analysis of the incipience of nucleate boiling has been developed as a modification and extension of the previous analyses for the wall superheat including the effect of submergence. The minimum degree of wall superheat required for the onset of fully developed boiling of liquid was related to the thermophysical properties of test liquids. The model prediction was made with the experimental data available in literature for nine organic liquids including water. The results predicted from the theoretical model were found to be consistent with the data. An effort was also made to obtain a unified correlation for nine different fluids, together covering wide ranges of heat flux, submergence and inlet liquid subcooling. It was observed that the majority of the data points lie within a maximum error of ±22% and mean absolute deviation of 16 percent.