| US 7,484,926 B2 | ||
| Steam turbine power plant | ||
| Takeo Suga, Yokohama (Japan); Ryuichi Ishii, Edogawa-ku (Japan); Takeo Takahashi, Yokohama (Japan); and Masafumi Fukuda, Saitama (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Mar. 15, 2006, as Appl. No. 11/375,463. | ||
| Claims priority of application No. 2005-130966 (JP), filed on Apr. 28, 2005. | ||
| Prior Publication US 2006/0245911 A1, Nov. 02, 2006 | ||
| Int. Cl. F01D 25/26 (2006.01); F01D 1/00 (2006.01) | ||
| U.S. Cl. 415—108 [415/200; 415/220; 416/241 R; 420/37; 420/445; 420/446; 420/447; 420/448; 420/449; 420/450] | 6 Claims |
| 1. A steam turbine power plant which is provided with an extra-high-pressure turbine, a high-pressure turbine, an intermediate-pressure
turbine and a low-pressure turbine, and has high-temperature steam of 650° C. or more introduced into the extra-high-pressure
turbine;
wherein the extra-high-pressure turbine comprises:
a double-structured casing which is comprised of an outer casing and an inner casing; and
an outer casing cooling unit which cools the outer casing by introducing cooling steam between the outer casing and the inner
casing;
a turbine rotor of the extra-high-pressure turbine is formed of a heat-resisting alloy which contains in percent by weight
C: 0.10-0.20, Si: 0.01-0.5, Mn: 0.01-0.5, Cr: 20-23, Co: 10-15, Mo: 8-10, Al: 0.01-1.5, Ti: 0.01-0.6, B: 0.001-0.006 and the
balance of Ni and unavoidable impurities, and it is suppressed in the unavoidable impurities that Fe is 5 or less, P is 0.015
or less, S is 0.015 or less and Cu is 0.5 or less;
the inner casing and a nozzle box of the extra-high-pressure turbine are formed of a heat-resisting alloy which contains in
percent by weight C: 0.03-0.25, Si: 0.01-1.0, Mn: 0.01-1.0, Cr: 20-23, Mo: 8-10, Nb: 1.15-3.0, and the balance of Ni and unavoidable
impurities, and it is suppressed in the unavoidable impurities that Fe is 5 or less, P is 0.015 or less, S is 0.015 or less,
and Cu is 0.5 or less; and
the outer casing of the extra-high-pressure turbine is formed of a cast steel which contains in percent by weight C: 0.05-0.15,
Si: 0.3 or less, Mn: 0.1-1.5, Ni: 1.0 or less, Cr: 9 or more and less than 10, V: 0.1-0.3, Mo: 0.6-1.0, W: 1.5-2.0, Co: 1.0-4.0,
Nb: 0.02-0.08, B: 0.001-0.008, N: 0.005-0.1, Ti: 0.001-0.03 and the balance of Fe and unavoidable impurities.
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