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 nat ural circulation loop based on the drift flux model, taking flow pattern ch ange and subcooled boiling into consideration. Transcendental equations of non-dimensional loop mass flow rate under various conditions were also deri ved. The model proposed herein was verified by comparing our results with e xperimental data found in literature. In addition, various steady-state cha racteristics of a natural circulation loop were analyzed and discussed; the se characteristics include the one-third-power dependence of the single pha se mass flow rate on heating power, the incipient power of two-phase flow, the maximum mass flow rate, and the existence of multiple solutions under c ertain conditions. This study also examined the effects of changing importa nt parameters. (C) 1999 Elsevier Science Ltd. All rights reserved.