| 摘要 |
PURPOSE:To prevent damage due to thermal fatigue by providing a steam inlet pipe which is a separate body from inner and outer casings of a steam turbine, and providing a cooling port near the connected part of the outer casing and a steam piping. CONSTITUTION:Between an outer casing 15 and an inner casing is provided a steam inlet pipe 29 which is a separate body from these casings and which is fitted in the fitting hole 15a of the outer casing 15. A seal ring 30 is fitted to the end of the steam inlet pipe 29, and is closely attached to the inner surface 16a of the end part of a steam piping 16. A cooling hole 32, which is connected to the fitting hole 15a, is provided near the connected part of the outer casing 15 and the steam piping 16. Thereby, since part of main steam 4 leaking from the seal ring 30 and flowing into the outer casing 15 is discharged together with cooled steam 26 from the cooling port 32 and since there is no corner that may generate stress concentration, damage due to thermal fatigue can be prevented. |
