The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 06, 2001
Filed:
Aug. 31, 1999
Masao Siga, Hitachiota, JP;
Takeshi Onoda, Hitachi, JP;
Shigeyoshi Nakamura, Hitachinaka, JP;
Ryo Hiraga, Hitachiota, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A combined cycle power generation system in which a generator is driven by a steam turbine and a gas turbine includes a steam turbine rotor having a mono-block rotor shaft with blades mounted thereon in multi-stages from a high pressure side to a low pressure side and a casing covering the rotor. An inlet temperature of steam to first stage blades is not less than 530° C. and the rotor shaft is made of a Ni—Cr—Mo—V low alloy steel of bainitic structure having a higher creep rupture strength at the high pressure side than at the low pressure side and a 538° C. and 10,h creep rupture strength not less than 12 kg/mm,at a central portion, and having mounted thereon at the central portion, first stage blades at the high pressure side or FATT of not more than 20° C. Final stage blades are mounted at the low pressure side having a room temperature V-notch impact value of not less than 4 kg/m, and blades of at least a final stage have a value of blade length in inches times revolution in rpm of not less than 125,000 and are made of martensite stainless steel including 8-13 wt. % Cr.