The Characteristics Study Of Two-phase Flow In Vapor Separation Space Of Steam Generator

The high quality steam is important to the safety and economical work of nuclear-powered equipments. As a crucial component of steam generator, the performance of separator device plays a very important role in steam generator performance. Only reasonable separator device could satisfy saturated steam wetness in the export of steam generator. Separator device performance would directly determine the quality of steam. As a component of steam generator, evaluating indicators of vapor separation space performance are pressure drop and separation rates.At present, the experimentation is main way to research separator device, especially the research of vapor separation space is relatively blank. The distribution of complex turbulent two-phase flow in vapor separation space is three-flow-field. In this article, according to the complex vapor-liquid multiphase flow, the separating mechanism of steam-water separator is researched, mathematical model is established. The flow field and the droplet trajectory are numerical analyzed using software for computing fluid dynamics. Results of this paper contribute to understanding the characteristics of separation device, especially the vapor separation space characteristics. Also it could lay the foundation for seeking more compact separator device.The main content of the research in the paper are as follows:a) According to the operating principle of separator device, droplet motion state and forces conditions in PWR vertical natural circulation steam generator are analyzed, separation mechanism in vapor separation space is also discussed.b) Numerical simulation is researched; appropriate turbulence model and two-phase model are selected to simulate flow law in vapor separation space.c) Geometric model of vapor separation space is established on the basis of reasonable simplification and assumptions. And the physical process is calculated and analyzed.d) Two-phase flow model of vapor separation space is researched through Lagrange particle tracking technology, reasonable droplet entry distribution is set, and the influence of separation rate affected by changes of operating parameters and spatial structure is analyzed.