Prediction of Critical Heat Flux in Non-Uniformly Heated Tubes Based on Two-Phase CFD

Abstract

In order to establish the critical heat flux (CHF) prediction method with non-uniform heat flux, as an additional approach for the safety analysis in the heat transfer systems, Eulerian two-fluid model coupled with wall boiling model are used to predict the critical heat flux in non-uniformly heated tubes. The calculated wall temperature and near-wall void fraction distributions under different heat fluxes are obtained and compared. The second peak of wall temperature and near wall void fraction are used as the criteria for CHF and the location of the highest near wall void fraction is regarded as the location of CHF. Two different power distributions are researched. The prediction has good agreement with the experiment, including both the CHF and their locations. Thus, the prediction method used in this paper can be used in the CHF prediction in non-uniformly heated tubes.