Critical Heat Flux Modeling in Pool Boiling for Steady-State and Power Transients

Understanding and predicting critical heat flux. (CHF) behavior during steady-state and transient conditions is of fundamental interest in the design, operation, and safety of boiling and two-phase flow devices. The results of a comprehensive study specifically conducted to model transient CHF in pool boiling are presented in this paper. The model we developed includes the analysis of thermal energy conduction within the heater coupled with a macrolayer thinning model. Statistical variations in the vapor mass behavior also are incorporated into the model. The resultant model provides new insight into the basic physics of the CHF phenomenon and indicates favorable agreement with the experimental data from cylindrical heaters with small radii.