An Influence of the Numerical Modeling of the Transition Between the Stator and Rotor on the Thermodynamic Condensation Loss in the Low-Pressure Part of a Steam Turbine

Abstract

Accuracy of numerical simulation of non-equilibrium steam condensation is strongly influenced by a condensation model, i.e. a nucleation rate model and a droplet growth model. Numerical studies of steam condensation in Laval nozzles show that the choice of the condensation model has a significant influence on nucleation rate, position of nucleation zone and consequently steam wetness and the droplet size in the nozzle outlet. It is necessary to model the transition area between rotating-rotor and stationary part-stator in numerical simulations of steam flow in steam turbines. For this purpose, “Stage” and “Frozen rotor” rotor-stator interface models are widely used. The aim of the present work has been to analyze how the numerical modeling of the rotor-stator transition area together with the condensation model influences the result of numerical simulation of flow with non-equilibrium steam condensation in the low pressure part of steam turbine of large power output.