Numerical simulation of wet steam transonic condensation flow in the last stage of a steam turbine

摘要

Purpose - The purpose of this paper is to study the condensation flow of wet steam in the last stage of a steam turbine and to obtain the distribution of condensation parameters such as nucleation rate, Mach number and wetness. Design/methodology/approach - Because of the sensitivity of the condensation parameter distribution, a double fluid numerical model and a realizable κ-ε-κ_d turbulence model were applied in this study, and the numerical solution for the non-equilibrium condensation flow is provided Findings - The simulation results are consistent with the experimental results of the Bakhtar test. The calculation results indicate that the degree of departure from saturation has a significant impact on the wet steam transonic condensation flow. When the inlet steam deviates from the saturation state, shock wave interference and vortex mixing also have a great influence on the distribution of water droplets. Originality/value - The research results can provide reference for steam turbine wetness losses evaluation and flow passage structure optimization design.