Abstract
The purpose of this study is to improve the critical power prediction accuracy of a film dry-out model at a high mass flux. The factor that overestimated the critical power in a high mass flux region was analyzed, and it was found from analysis results that entrainment due to boiling in the liquid film was the main factor. Both film dry-out models with and without the boiling effect was compared with a wide range of critical power data including BWR operating conditions. The average and standard deviations of prediction accuracy (prediction/measurement) without the boiling effect were 1.44 and 0.25, respectively. The prediction accuracies with the boiling effect were 0.98 and 0.097. Thus, the prediction accuracy was improved. It was clarified that the boiling in the thin liquid film was more likely to occur, using Chen’s forced convection correlation, Bergles-Rohsenow‘s onset boiling correlation and Tsukuda’s boiling curve.
