Reduction of Thermodynamic Losses in a Supersonic Nucleating Steam Nozzle by Spraying Water Droplets

During the course of expansion of steam in turbines, the vapour rst supercools and then nucleates to become a two-phase mixture. Formation of the liquid phase causes thermodynamic and aerodynamic losses in steam turbines. In this study, the treatment is a one-dimensional, non-equilibrium ow in a steady Laval nozzle. In this paper, the changes in the rate of nucleation, entropy, pressure and other parameters of the two-phase ow, subjected to spraying the liquid droplets close to the nozzle''s throat, are investigated. By injecting the water droplets into a supersonic condensing ow, the thermodynamic loss is considerably decreased. Keywords: Two-phase ow; Convergent-divergent nozzle; Nucleation.