Scaling of Horizontal Steam Generator Based on Three-Dimensional Thermal-Hydraulic Simulations

Abstract Thermal-hydraulics of horizontal steam generator (HSG) is numerically simulated and analyzed for the full-scale real HSG at the nominal 100% power built in the 1000 MWe nuclear power plant with the pressurized water reactor and for the scaled-down HSG design with all characteristic dimensions reduced to 50% of the full dimensions and operating at 12.5%, 15.7% and 18.7% of the 100% power of the real HSG. The scaled-down HSG designed is considered with the aim to investigate a design that suits the needs of a nuclear power plant with small modular reactor (SMR), which components should be manufactured in a factory and transported to and assembled at the power plant location. The several power levels of the scaled HSG are applied in the performed simulations in order to obtain steam void and water and steam velocities fields that should provide operating parameter values close to the proven safe and reliable values of the 100% full-scale HSG with mature operating experience. The simulations are performed with an in-house code based on the three-dimensional two-fluid model of two-phase flow and appropriate closure laws for the prediction of interface transport processes, such as vapour-liquid interface friction, vapour and liquid wall friction and liquid evaporation rate under thermal non-equilibrium conditions. The obtained results show a difference between geometry and power scaling. The 50% geometry reduction leads to about 80% of HSG power reduction.