The numerical simulation of steam wetness in variable working conditions for the last stage of LP-steam turbine

During the cause of expansion in turbines steam nucleates to become a two-phase mixture consisting of a very large number of extremely small droplets carried by the vapour. Turbine stages operating in a two-phase regime have a lower efficiency than those working on superheated steam and the turbine blades could be erosioned by the droplets. In order to investigated the influence of steam nucleation in different load, a three-dimensional nucleating wet steam flow with homogeneous nucleation in the last stage of an LP-steam turbine is simulated and analysised, including wetness faction distributions in different height of blade, wetness distribution and supercooling distribution in the channel of mid-height in different load.