BT-29 Thermal Non-Equilibrium: The Effect of Noncondensable Gas on Boiling Fluids

L. Huang

The boiling point of a fluid decreases as the concentration of noncondensable gas increases. Accurately predicting the bulk temperature of two-phase flow with a noncondensable gas is crucial to the thermal design of evaporators or reboilers with sparge gas. Our experimental data for intube flow boiling with a noncondensable gas indicate that the true two-phase bulk temperature can be much higher than the equilibrium temperature assuming an ideal mixture if the concentration of noncondensable gas is high. Based on our recent n-pentane/nitrogen mixture data, we propose a simplified correlation for determining the two-phase bulk temperature and the current intube flow boiling model predictions of HTRI Xchanger Suite® 2.0.