Numerička simulacija dvofaznog strujanja i razmene toplote u vertikalnom generatoru pare

In this paper is presented a two-dimensional, thermal-hydraulic, two-fluid model of two-phase flow around tubes in a bundle at the secondary shell side of the vertical steam generator. A model for the prediction of heat transfer from the primary to the secondary side is also included. The two-fluid model is applied for the two-phase flow simulation at the shell side of the steam generator and it is based on mass, momentum and energy balance equations for each phase. Interface processes are de-termined by closure laws. Furthermore, different ways of modelling interfacial friction force are pre-sented as used in commercial CFD software and nuclear reactor safety codes. Prediction of heat flux is performed by using a heat transfer model that includes mechanisms of single-phase convection and subcooled and saturated flow boiling. The obtained results are compared with measured data availa-ble in the literature. The developed model is a support for the design of steam generators. The ob-tained results represent a detailed insight into thermal-hydraulic process of the vertical steam genera-tor.