Effects of superheated steam on non-equilibrium condensation in ejector primary nozzle

•Wet steam model for non-equilibrium condensation in Laval nozzle was built.•Validation of simulation data with experiment results.•Effects of superheated steam on condensation in nozzle were fully studied.•Increase of superheat attenuates condensation shock and enhances steam stability.

In order to reduce the non-equilibrium condensation occurring in ejector primary nozzle, wet steam model was adopted to investigate the relationship between steam superheated level and non-equilibrium condensation within ejector primary nozzle. Simulation data of axial static pressure along primary nozzles were validated with experimental data reported in literature. The non-equilibrium condensation process from homogeneous nucleation to droplet growth stage and the resulting products were carefully studied. Moreover, six inlet superheated levels from 5 K to 30 K with the increment of 5 K were compared, and simulation results showed that the increase of superheated level from 5 K to 30 K causes 40.22% delay in the location and 43.92% reduction in the intensity of the condensation shock. Furthermore, there is about 24.30% liquid mass fraction decrease when the superheated level raises to 30 K and total entropy generation increases slowly with the increase of superheated level.