A Theoretical Analysis of Flow Through the Nucleating Stage in a Low Pressure Steam Turbine

Abstract

In order to improve steam efficiency and reliability, the phenomena associated with the formation and growth of water droplets must be understood. This paper describes a theoretical investigation into flow behavior in the nucleating stage, where the predictions of a one-dimensional theory are compared with measured turbine data. Results indicate that droplet sizes predicted by homogeneous condensation theory cannot be reconciled with measurements unless fluctuating shock waves arise. Heterogeneous effects and flow turbulence are also discussed along with their implications for the condensation process.