Loading patent…
AssigneeHitachi, Ltd.
InventorsMitsuo Kuriyama, Masao Shiga, Kishio Hidaka, Shigeyoshi Nakamura, Yutaka Fukui, Ryo Hiraga, Nobuo Shimizu, Masao Kawakami
Estimating the term…
A steam turbine has main components such as rotor shaft exposed to high temperature and intermediate pressure, which are made of a ferritic steel and the main steam temperature and the re-heat steam temperature are 610.degree. C. to 660.degree. C., and a steam turbine power plant employs the turbine. Further, the rotating blades are made of only a martensitic steel or a combination of the martensitic steel and a Ni base alloy, the turbine rotor is made of a ferritic forged steel having a creep rupture strength at the operating temperature for 100 thousands hours of above 15 kg/mm.sup.2, and the casing is made of a ferritic cast steel having a creep rupture strength at the operating temperature for 100 thousands hours of above 10 kg/mm.sup.2.
A high strength heat resisting cast steel which contains C of 0.06 to 0.16%, Si of not more than 1%, Mn of not more than 1%, Cr of 8 to 12%, Ni of 0.1 to 1.0%, V of 0.05 to 0.3%, Nb of 0.01 to 0.15%, N of 0.01 to 0.1%, Mo of not more than 1.5%, W of 1 to 3%, B of 0.0005 to 0.003% and necessarily includes O, and wherein said amount of O is not more than 0.010% in weight percentages.
A high strength heat resisting cast steel which contains C of 0.09 to 0.14%, Si of not more than 0.3%, Mn of 0.40 to 0.70%, Cr of 8 to 10%, Ni of 0.4 to 0.7%, V of 0.15 to 0.25 %, Nb of 0.04 to 0.08%, N of 0.02 to 0.06%, Mo of 0.40 to 0.80%, W of 1.4 to 1.9%, B of 0.001 to 0.0025% and necessarily includes, O, and wherein said amount of O is not more than 0.010% in weight percentages and the remainder of Fe and inevitable impurities.
A steam turbine casing made of a cast steel which contains C of 0.06 to 0.16%, Si of not more than 1%, Mn of not more than 1%, Cr of 8 to 12%, Ni of 0.1 to 1.0%, V of 0.05 to 0.3%, Nb of 0.01 to 0.15%, N of 0.01 to 0.1%, Mo of not more than 1.5%, W of 1 to 3%, B of 0.0005 to 0.003% and necessarily includes O, and wherein said amount of O is not more than 0.010% in weight percentages.
A steam turbine casing made of a cast steel which contains C of 0.09 to 0.14%, Si of not more than 0.3%, Mn of 0.40 to 0.70%, Cr of 8 to 10%, Ni of 0.4 to 0.7%, V of 0.15 to 0.25 %, Nb of 0.04 to 0.08%, N of 0.02 to 0.06%, Mo of 0.40 to 0.80%, W of 1.4 to 1.9%, B of 0.001 to 0.0025% and necessarily includes, O, and wherein said amount of O is not more than 0.010% in weight percentages and the remainder of Fe and inevitable impurities.
A steam turbine power plant having a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, wherein the inlet steam temperature to the rotating blades in the first stages of said high pressure steam turbine and said intermediate pressure steam turbine is 610 to 660.degree. C.;
A steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, said steam flowing to the first stage of said rotating blades having a temperature of 610 to 660.degree. C. and a pressure not lower than 150 kg/cm.sup.2, wherein said rotor shafts, the rotating blades and fixed blades at least in the first stages are made of a high strength martensitic steel having a martensitic structure containing Cr of 9 to 13 weight %, said high strength martensitic steel having a creep rupture strength at a temperature corresponding to said steam temperature for 1 hours of not less than 15 kg/mm.sup.2, while other rotating blades therefore are made of a combination of said martensitic steel and a Ni base alloy having a tensile strength at room temperature not less than 90 kg/mm.sup.2 ;
A steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein said rotor shaft and said fixed blades at least in the first stage are made of a high strength martensitic steel containing C of 0.05 to 0.20%, Si of not more than 0.15%, Mn of 0.03 to 1.5%, Cr of 9.5 to 13%, Ni of 0.05 to 1.0%, V of 0.05 to 0.35%, Nb of 0.01 to 0.20%, N of 0.01 to 0.06%, Mo of 0.05 to 0.5%, W of 1.0 to 3.5%, Co of 2 to 10%, B of 0.0005 to 0.03%, and having Fe of not less than 78% in weight percentages;
A high pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein the first stage of said rotating blades is of a double flow construction and more than seven stages of said rotating blades, except for the first stage, are provided in one side, said rotor shaft having a distance (L) between bearing centers of not less than 5000 mm and a minimum diameter (D) at portions having said fixed blades of not less than 600 mm, the ratio (L/D) being 8.0 to 9.0, some rotating blades and said rotor shaft being made of a high strength martensitic steel containing Cr of 9 to 13 weight %, and other rotating blades being made of a combination of some martensitic steel and a Ni base alloy, said inner casing being made of a martensitic cast steel containing Cr of 8 to 12 weight % and having a creep rupture strength at a temperature corresponding to said steam temperature for 10.sup.5 hours of not less than 9 kg/mm and an impact value at room temperature of not less than 3.2 kg-m.
An intermediate pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein more than six stages of said rotating blades are symmetrically provided in right hand side and left hand side and the first stages of said rotating blades are implanted in the middle portion of said rotor shaft to form a double flow construction, said rotor shaft having a distance (L) between bearing centers of not less than 5000 mm and a minimum diameter (D) at portions having said fixed blades of not less than 600 mm, the ratio (L/D) being 8.2 to 9.2, rotating blades and said rotor shaft being made of a high strength martensitic steel containing Cr of 9 to 13 weight %, otherwise said rotating blades being made of a combination of said martensitic steel and a Ni base alloy, said inner casing being made of a martensitic cast steel containing Cr of 8 to 12 weight % and having a creep rupture strength at a temperature corresponding to said steam temperature for 10 hours of not less than 9 kg/mm2 and an impact value at room temperature of not less than 3.2 kg-m.
A steam turbine power plant having a high pressure steam turbine and an intermediate pressure steam turbine connected to two low pressure steam turbines connected to each other in tandem, wherein the inlet steam temperature to the rotating blades in first stages of said high pressure steam turbine and said intermediate pressure steam turbine is 610 to 660.degree. C.;
A coal fired thermal power plant having a coal fired boiler, a steam turbine system driven by steam produced by said boiler, at most two electric power generators having an output power not less than 1000 MW produced by at least one unit driven by said steam turbine, wherein said steam turbine system includes a high pressure steam turbine, an intermediate pressure steam turbine and two low pressure steam turbines connected to said high pressure steam turbine;
A high pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein said rotating blades are composed of more than seven stages and the blade lengths are from 35 mm in the upstream side to 210 mm in the downstream side;
A high pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein said rotating blades are composed of more than seven stages and the blade lengths are from 35 mm in the upstream side to 210 mm in the downstream side;
A high pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein said rotating blades are composed of more than seven stages and the blade lengths are from 35 mm in the upstream side to 210 mm in the downstream side;
An intermediate pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein more than six stages of said rotating blades are symmetrically provided in a right hand side and a left hand side to form a double flow construction, the blade lengths of said rotating blades are 100 mm in the upstream side to 300 mm in the downstream side;
An intermediate pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein more than six stages of said rotating blades are symmetrically provided in a right hand side and a left hand side to form a double flow construction, blade lengths of said rotating blades are 100 mm in the upstream side to 300 mm in the downstream side;
An intermediate pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein more than six stages of said rotating blades are symmetrically provided in a right hand side and a left hand side to form a double flow construction, the blade lengths of said rotating blades are 100 mm in the upstream side to 300 mm in the down stream side;
A high pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein said rotating blades are composed of more than seven stages;
An intermediate pressure steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, wherein said rotating blades are composed of more than six stages;
A steam turbine having a rotor shaft, rotating blades implanted onto said rotor shaft, fixed blades for guiding steam flow to said rotating blades and an inner casing supporting said fixed blades, said steam flowing to the first stage of said rotating blades having a temperature of 610 to 660.degree. C., wherein said rotor shaft and said inner casing are made of a martensitic steel containing Cr of 8 to 13 weight %;
A steam turbine power plant having a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, wherein the inlet steam temperature to the rotating blades in the first stages of said high pressure steam turbine and said intermediate pressure steam turbine is 610 to 660.degree. C.;
A steam turbine power plant having a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, wherein the inlet steam temperature to the rotating blades in the first stages of said high pressure steam turbine and said intermediate pressure steam turbine is 610 to 660.degree. C.;
A steam turbine power plant having a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, wherein the inlet steam temperature to the rotating blades in the first stages of said high pressure steam turbine and said intermediate pressure steam turbine is 610 to 660.degree. C.;
A steam turbine power plant having a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, wherein the inlet steam temperature to the rotating blades in the first stages of said high pressure steam turbine and said intermediate pressure steam turbine is 610 to 660.degree. C.;
A high strength heat resisting cast steel which contains C of 0.06 to 0.16%, Si of not more than 1%, Mn of not more than 1%, Cr of 8 to 12%, Ni of 0.1 to 1.0%, V of 0.05 to 0.3%, Nb of 0.01 to 0.15%, N of 0.01 to 0.1%, Mo of not more than 1.5%, W of 1 to 3%, B of 0.0005 to 0.003% and necessarily includes O, wherein said O is Present in an amount of not more than 0.010% in weight percentages, wherein the creep rupture strength at 625.degree. C. for 10.sup.5 hours is not less than 9 kgf/mm.sup.2 and the impact value at room temperature is not less than 3.2 kgf-m.
Dependencies are inferred from the claim text.