Taking the long last stage blades of steam turbine in a 1 000 MW unit as the research objects

the condensation flow and droplet deposition in the last two stages were numerically calculated by CFX software.Effects of such dehumidification structure design parameters as the slot position

slot angle

slot width and slot number on the humidification efficiency

second water droplet removal rate and stage efficiency were investigated in detail.The results show that

to ensure excellent performance for the last stage blades

like well humidification property

high stage efficiency and great stationary blade strength

the moisture removal suction slots should be located at the place higher than 60%of the relative blade high in radial direction

and in the axial position of 80.6% and 29.2% relative blade width on the pressure and suction surfaces respectively.In addition

the slot angle should be 45°and the width ought to be 1.0 mm.If not considering the hollow stationary blade's strength

the single-stage humidification slot had better comprehensive performance.With the same slot area

the double-slot humidification slot was better.When the slot width is the same

the single-slot humidification slot was better.