Numerical Study on High-speed Heterogeneous Condensation Flow of Wet Steam

Based on sphere-cap-shaped nucleation mechanism, a numerical model of two-phase heterogeneous condensation flow of wet steam was established, with which numerical simulations were conducted on the heterogeneous condensation flow in Laval nozzle, turbine cascade and turbine stage respectively. Results show that in comparison with spontaneous condensation, the impurity particles in heterogeneous condensation flow change the condensation process, reduce the intensity of condensation shock in the Laval nozzle, alter the pressure distribution in the turbine cascade, reduce the supercooling degree of steam, and lower the thermodynamic loss of non-equilibrium. In the turbine stage, the inlet and outlet angle of heterogeneous condensation flow around rotor and stator are close to those of superheated steam flow, and its pressure before rotor blade is higher than that of superheated steam, but its degree of reaction deviates from corresponding values in superheated steam flow.