Analysis of two-phase flow characteristics in a natural circulation loop using the drift-flux model taking flow pattern change and subcooled boiling into consideration

This study investigated the steady-state characteristics of a two-phase natural circulation loop based on the driftflux model, takingflow pattern change and subcooled boiling into consideration. Transcendental equations of non-dimensional loop massflow rate under var- ious conditions were also derived. The model proposed herein was verified by comparing our results with experimental data found in literature. In addition, various steady-state char- acteristics of a natural circulation loop were analyzed and discussed; these characteristics include the one-third-power dependence of the single phase massflow rate on heating power, the incipient power of two-phaseflow, the maximum massflow rate, and the existence of multiple solutions under certain conditions. This study also examined the e€ects of changing important parameters