Numerical simulation of wet steam two-phase flow in the last-stage stationary blade of super-critical steam turbine

Abstract

For the last-stage blades of super-critical steam turbine, the problem of water erosion is serious. Using the design parameters of the last stage static and moving blade of a SC 600MW steam turbine, two-dimensional and three-dimensional numerical simulation of the flow field are carried out in this paper. And the distributing situation of the mach number, pressure, liquid density, nucleation rate and critical radius in the cascade channel are calculated. The pressure distribution of two-dimensional simulation is consistent with the experimental data in literature. The simulation results of three-dimensional indicate that, above 0.5 relative blade height, the wet steam flow characteristics change slightly along the radial direction. So the steam condensing flow in three-dimensional cascade under such condition can be simplified to two-dimensional flow.