Critical flow leakage of a vapour-liquid mixture from sub-cooled water: Nucleation boiling study

摘要

Two-phase critical flow has been studied extensively by many researchers over the past seven decades, due to its importance in the fields of nuclear engineering and other industries that deal with high energy storage. The paper aims to develop a mathematical model for the critical flow of a two-phase mixture in a narrow channel, considering the irreversible non-equilibrium interphase mass transfer of metastable liquids. Calculations are based on the model to describe the boiling delay and the non-equilibrium vapor generation process during a rapid depressurization. Moreover, the paper provides an explicit algorithm, using the computational pressure step, to seek efficiency and precision as well as the stability of the computation. The possibility of this model to predict the critical mass flux, pressure profiles, as well as the mass transfer between phases, has been validated, by comparison with three mathematical models with respect to experimental results of different authors. The developed non-equilibrium model gives an excellent approach to experimental measures and explains the complex behavior shown by critical blow-downs of pressurized vessels. (C) 2019 Elsevier Ltd. All rights reserved.