Three-dimensional numerical simulation of the interaction between high-pressure sub-cooled water jet impacting high-temperature liquid lead-bismuth metal

Abstract

The rupture accident of the steam generator heat transfer tube of the lead-bismuth cooled fast reactor causes a high-pressure sub-cooled water jet impacting high-temperature liquid lead-bismuth, and the interaction mechanism between water and liquid lead-bismuth needs to be studied clearly. In this paper, based on the volume of fluid method, the LES turbulence model and the Lee phase transition model, a three-dimensional numerical model is developed to study the multiphase flow and heat transfer mechanism of water and lead-bismuth interaction. The effects of sub-cooled water temperature, inlet pressure, and nozzle diameter on the distribution of phase state, pressure, temperature, and generated steam volume are studied in detail. The results indicate that the water jet can be divided into the jet water zone, the water-steam mixed zone, and the multiphase flow zone, respectively. Among them, the appearance of water-steam mixed zone depends on the internal boiling of the jet, and this zone tends to appear under the condition of low inlet pressure, small nozzle diameter and high sub-cooled water temperature. For multiphase flow zone, the temperature increases with sub-cooled water temperature, decreases with nozzle diameter and is almost not influenced by inlet pressure; The pressure increases with sub-cooled water temperature, inlet pressure and nozzle diameter. When nozzle diameter is large enough, however, it no longer has any effect on the temperature and pressure distribution within the jet. The volume of steam generated by water boiling is positively correlated with all three factors. Overall, the steam migrates upward through the outer side of the jet, absorbing heat and expanding during the migration process, and forming a high-temperature area at the top of the jet.