Assessment of horizontal in-tube condensation models using MARS code. Part II: Annular flow condensation

Abstract

Assessments on the predictive capability of various horizontal in-tube condensation models are performed using the multi-dimensional analysis of reactor safety (MARS) code. In Part I of this two-part paper, the assessments of the stratified flow condensation models were presented while, in Part II, the assessments of the annular flow condensation models are presented. In order to assess the annular flow condensation models, total 19 condensation models were collected from the published literature and incorporated in MARS code, and the heat transfer data was collected from three condensation experiments: JAEA-PCCS, PASCAL, and NOKO experiments. From the assessments, it was found that the present MARS code with combination of the Shah and Chato models under-predicted the condensation heat transfer generally, and the models by Cavallini and Zecchin, Dobson and Chato, Kosky and Staub, Traviss et al., Moser et al., etc., had good predictive capabilities on the condensation heat transfer for the steam-water annular flow. Furthermore, it was found that the stratified flow condensation model by Cavallini et al. (2006), which showed good predictive capability for the Purdue-PCCS experiment (in Part I), was good to use for the prediction of the condensation heat transfer for various steam-water stratified flow conditions. It is expected that the results of this study can be used to significantly improve the condensation models in thermal hydraulic code such as RELAP5 or MARS code.