High and low pressure sides-integrating system turbine, long blades thereof and combined cycle power generation system

A combined cycle power generation system in which a generator is driven by a steam turbine and a gas turbine,

• wherein said steam turbine is a high and low pressure side integrating steam turbine for 50 Hz power generation operating at 3,000 rpm and comprises a 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 said rotor, an inlet temperature of steam to first stage blades being not less than 530° C., and
• wherein said 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 or a higher toughness at the low pressure side than at the high pressure side, and a 538° C. and 105 h creep rupture strength of not less than 12 kg/mm2 at a central portion having mounted thereon first stage blades at the high pressure side or FATT of not more than 20° C. at a central portion and final stage blades at the low pressure side having a room temperature V-notch impact value of not less than 4 kg-m, and
• wherein blades of at least a final stage each have a blade portion length of 41.7 inches or more and are made of martensite stainless steel, said martensite stainless steel having a 20° C. V-notch sharpy impact value of 2.5 kgm/cm2 or more and a room temperature tensile strength of 120 kg/mm2 or more, and said impact value (kgm/cm2) being not less than a value obtained by −0.6x+77.2 when said room temperature tensile strength in kg/mm2 is denoted by x.

A combined cycle power generation system in which a generator is driven by a steam turbine and a gas turbine,

• wherein said steam turbine is a high and low pressure side integrating steam turbine for 60 Hz power generation operating at 3,6000 rpm and comprises a 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 said rotor, an inlet temperature of steam to first stage blades being not less than 530° C., and
• wherein said 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 or a higher toughness at the low pressure side than at the high pressure side, and a 538° C. and 105 h creep rupture strength of not less than 12 kg/mm2 at a central portion having mounted thereon first stage blades at the high pressure side or FATT of not more than 20° C. at a central portion and final stage blades at the low pressure side having a room temperature V-notch impact value of not less than 4 kg-m, and
• wherein blades of at least a final stage each have a blade portion length of 34.7 inches or more and are made of martensite stainless steel, said martensite stainless steel having a 20° C. V-notch sharpy impact value of 2.5 kgm/cm2 or more and a room temperature tensile strength of 120 kg/mm2 or more, and said impact value (kgm/cm2) being not less than a value obtained by −0.6+77.2 when said room temperature tensile strength in kg/mm2 is denoted by x.

A combined cycle power generation system in which a generator is driven by a steam turbine and a gas turbine,

• wherein said steam turbine is a high and low pressure side integrating steam turbine for 50 Hz power generation operating at 3,000 and comprises a 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 said rotor, an inlet temperature of steam to first stage blades being not less than 530° C., and
• wherein said rotor shaft is made of a low alloy steel of bainitic structure comprising, by weight percentage, 0.18-0.28% C, not more than 0.1% Si, 0.1-0.3% Mn, 1.5-2.5% Cr, 1.5-2.5% Ni, 1-2% Mo and 0.1-0.35% V, and having a higher creep rupture strength at the high pressure side than at the low pressure side or a higher toughness at the low pressure side than at the high pressure side, a 538° C. and 105 h flatness-and notch-creep rupture strength of not less than 13 kg/mm2 at a central portion having mounted thereon first stage blades at the high pressure side having a tensile strength of not less than 84 kg/mm2 and FATT of not more than 20° C. and final stage blades at the low pressure side having a room temperature V-notch impact value of not less than 4 kg-m, and
• wherein blades of at least a final stage each are made of martensite stainless steel comprising, by weight percentage, 0.08-0.18% C, not more than 0.25% Si, not more than 0.90% Mn, 8.0-13.0% Cr, 2-3% Ni, 1.5-3.0% Mo, 0.05-0.35% V, 0.02-0.20% in total of at least one kind of Nb and Ta and 0.02-0.10% N, and have a blade portion length of not less than 43 inches and a room temperature tensile strength of 128.5 g/mm2 or more.

A combined cycle power generation system in which a generator is driven by a steam turbine and a gas turbine,

• wherein said steam turbine is a high and low pressure side integrating steam turbine for 60 Hz power generation operating at 3,600 rpm and comprises a 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 said rotor, an inlet temperature of steam to first stage blades being not less than 530° C., and
• wherein said rotor shaft is made of a low alloy steel of bainitic structure comprising, by weight percentage, 0.18-0.28% C, not more than 0.1% Si, 0.1-0.3% Mn, 1.5-2.5% Cr, 1.5-2.5% Ni, 1-2% Mo and 0.1-0.35% V, and having a higher creep rupture strength at the high pressure side than at the low pressure side or a higher toughness at the low pressure side than at the high pressure side, a 538° C. and 105 h flatness-and notch-creep rupture strength of not less than 13 kg/mm2 at a central portion having mounted thereon first stage blades at the high pressure side, and a tensile strength of not less than 84 kg/mm2 and FATT of not more than 20° C. and final stage blades at the low pressure side having a room temperature V-notch impact value of not less than 4 kg-m, and
• wherein blades of at least a final stage each are made of martensite stainless steel comprising, by weight percentage, 0.08-0.18% C, not more than 0.25% Si, not more than 0.09% Mn, 8.0-13.0% Cr, 2-3% Ni, 1.5-3.0% Mo, 0.05-0.35% V, 0.02-0.20% in total of at least one kind of Nb and Ta and 0.02-0.10% N, and have a blade portion length of not less than 37 inches and room temperature tensile strength of 128.5 kg/mm2 or more.