| 摘要 |
PURPOSE:To reduce stress of a rotor, by providing an axial flow compressor device to a space formed between the rotor and the internal surface of a nozzle box and flowing cooling steam, which flows in through a hole extended through a stationary blade, into the upstream of the rotor through pumping action of said axial flow compressor device. CONSTITUTION:A space S formed between a rotor 7 and the internal surface of a nozzle box 1 is communicated to a passage 22 extended through a stationary blade 2, and a screw seal 8 is provided to a surface of the rotor 7. Rotation of the rotor 7 causes pumping action of the screw seal 8, and cooling steam flowing in via the passage 22 is penetratively circulated to the upstream of the rotor 7. In this way, since the rotor 7 can be cooled without causing the necessity for forming an annular train of holes in a disc part of the rotor 7, the generation of concentrated stress due to the hole can be prevented. |
