| 摘要 |
PURPOSE:To adjust a gap between tip sections of rotor blades and seal fins and reduce the leaked stream quantity by arranging bellows expandable in the axial direction on a stationary section faced to inclined tip sections of the rotor blades, and planting seal fins on the bellows. CONSTITUTION:Bellows 4 expandable in the axial direction of a turbine are arranged on a diaphragm outer periphery section 3 faced to tip sections 2a of inclined rotor blades 2 of the steam turbine, and multiple seal fins 5 are planted on outer peripheries of the bellows 4. The bellows 4 can be selectively connected to a high-pressure source 6 or a low-pressure source 8. The bellows 4 are connected to the lower-pressure source 8 when the turbine is started and stopped or a load is fluctuated, the bellows 4 are shrunk to the stator blades 1 side, and a gap between tip sections 21 of the rotor blades 2 and the seal fins 5 is increased to avoid the contact between both 2a, 5. The bellows 4 are connected to the high-pressure source 6 during the stationary operation, and the gap between the tip sections 2a of the rotor blades 2 and the seal fins 5 in the radial direction of the turbine is narrowed to reduce the leaked steam quantity. |
