A Study on Limiting Exit Quality of CHF of Forced Convection Boiling in Uniformly Heated Vertical Channels

This paper presents the results from a phenomenological analysis of limited exit quality X°_ex, that is, the occurrence of critical heat flux at a nearly constant exit quality X°_ex independent of the change of inlet quality under mixed inlet condition. The author’s generalized correlation equations of CHF in uniformly heated channels with subcooled inlet condition are employed for this purpose, and the prediction of X°_ex is compared with the existing data of X°_ex satisfactorily. As a basis of the above-mentioned analysis, the applicability of the author’s correlation equations to the state near the critical length-to-diameter ratio corresponding to the limiting quality condition is also examined.