Fluid-to-Fluid Modeling of Critical Heat Flux in a 4×4 Rod Bundle

摘要

The CHF experiments of 4×4 rod bundle are carried out in Freon-12 thermal hydraulicrntest facility of NPIC. 170 CHF data are collected in 4×4 rod bundle in Freon-12 in thernconditions of 1.59～2.73MPa, 488～2080 kg/m2.s and critical quality -0.20～0.30. A fewrnfluid-to-fluid modeling of CHF methods are assessed. It shows that the deviations ofrnS.Y.Ahmad Compensation Distortion Model, Zhangzhenjie Model and Groeneveld Model arernbeyond 20% except of the Stevens-Kirby Model. Based on empirical scaling factor approach,rnthe author proposes the empirical correlation of flow scaling factor k, which fits all data withinrn±15% with an rms error of 4.17 % and improve the CHF prediction in 4×4 rod bundle.rnFurthermore the author simply analyses the effect of spacer grid on the CHF modeling of 4×4rnrod bundle and underlines further study on this aspect is needed.