JPH08239727A - Gas turbine and multiple electric power plant - Google Patents

Abstract

PURPOSE: To meet a recent demand for the elevation of temp. and to improve reliability by constituting a gas turbine of a material having respectively specified composition and strength characteristic. CONSTITUTION: An Ni-base alloy, having a composition consisting of, by weight ratio, 0.05-0.20% C, 20-25% Co, 15-25% Cr, 1.0-3.0% Al, 1.0-3.0% Ti, 1.0-3.0% Nb, and >=55% Ni, is used for a first-stage gas injection nozzle among the important members of turbine composed of disks of more than three stages, and further, the preheating temp. causing no crack at the time of TIG welding is regulated to <=400 deg.C. The nozzles of the second and subsequent stages are composed of Co-base alloy. Moreover, a blade is composed of an Ni-base cast alloy having a composition consisting of 0.07-0.25% C, <=1% Si, <=1% Mn, 12-20% Cr, 5-15% Co, 0.005-0.03% B, 2-7% Ti, 3-7% Al, <=1.5% Nb, and >=50% Ni and also having γ' and γ'' phases. Further, the disk, in which the blade is to be planted, is composed of a martensitic steel in which fracture strength at 450 deg.C and 10<3> h is regulated to 40kg/mm<2> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine using a novel Ni-based alloy and a combined combined power generation system in which the gas turbine and the steam turbine are integrated.

[0002]

2. Description of the Related Art As an industrial gas turbine nozzle (stating vane) material, a Co-based alloy is used from the viewpoint of corrosion resistance and weldability. However, as the combustion temperature (turbine inlet temperature) rises with the recent improvement in efficiency, an alloy having excellent high-temperature strength and heat fatigue resistance is required to replace the Co-based alloy. On the other hand, Ni-based superalloys used for blades (moving blades) are alloys that are superior in high temperature strength and thermal fatigue resistance to Co-based alloys, but welding is extremely difficult and welding such as repair welding is performed. Is difficult to apply to nozzles that require

A Ni-based alloy for nozzles is disclosed in Japanese Patent Laid-Open No. 60-
No. 100641 and U.S. Pat.
4810467 is an example.

[0004]

The above-mentioned prior art is intended to improve the weldability at the expense of high temperature strength, and no consideration is given to high temperature strength, particularly long-term strength, from the viewpoint of increasing service temperature and extending life. .

The object of the present invention is to obtain N that is excellent in heat fatigue resistance and high temperature strength, especially creep rupture strength, and is weldable.
An object of the present invention is to provide a combined power generation system including a gas turbine and a steam turbine, which uses a gas turbine nozzle made of an i-based alloy.

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, a gas for causing combustion gas combusted by air compressed by a compressor to collide with blades respectively implanted in three or more stages of disks through nozzles to rotate the blades. In the turbine, the nozzle has a blade portion and sidewalls formed at both ends of the blade portion and is arranged in a ring shape on the outer periphery of the rotating blade, and the first stage on the combustion gas inlet side has a weight of C0. 05-0.20%, Co20-25%, Cr
15-25%, Al 1.0-3.0%, Ti 1.0-3.0
%, Nb 1.0-3.0%, W 5-10% and Ni 55%
The above Ni-based alloy containing Ni, the second and subsequent stages are C by weight
0.2-0.6%, Si2% or less, Mn2% or less, Cr2
5 to 35%, Ni 5 to 15%, W3 to 10%, B0.0
A gas turbine is characterized by being made of a Co-based alloy having 03 to 0.03% and Co of 50% or more.

In the present invention, the blade has a weight of C
0.07-0.25%, Si 1% or less, Mn 1% or less, C
r12-20%, Co5-15%, Mo1-5%, W1
~ 5%, B0.005-0.03%, Ti2-7%, Al
3 to 7%, Nb 1.5% or less, Zr 0.01 to 0.5%,
More preferably, Hf 0.01-0.5%, V0.01-
0.5%, Ta 5% or less, Re 5% or less, rare earth element 0.1.
It is preferable that the Ni-based casting alloy has Ni of 5% or less and 50% or more and has a γ'phase.

[0008] It is preferable that an Al or Cr diffusion coating layer is provided on at least the surface of the blade of the blade after the third stage.

In the gas turbine according to the present invention, which is exposed to combustion gas and has a plurality of nozzles in at least three stages, and a plurality of blades implanted in at least three stages of the disc, the disc is 450 ° C., 10 ⁵ It is preferably composed of martensitic steel having a h creep rupture strength of 40 kg / mm ² or more.

In the gas turbine according to the present invention, which comprises at least three stages of blades exposed to combustion gas and a ring-shaped shroud facing the blade tips, the shroud is one stage of the blades. The part facing the eye is the weight, C0.05-0.2%, Si
2% or less, Mn 2% or less, Cr 17-27%, Co 5%
Hereinafter, it is composed of a Ni-based alloy having Mo of 5 to 15%, W of 5% or less, B of 0.02% or less, and Fe of 10 to 30%, and the weight is C0.
3 to 0.6%, Si 2% or less, Mn 2% or less, Cr20
.About.27%, Ni 20-30%, Nb 0.1-0.5% and Ti 0.1-0.5%.

The gas turbine nozzle according to the present invention comprises:
By adjusting the addition amount of Al, Ti, etc. to be low, N
The weldability is improved by suppressing the precipitation amount of the γ'phase, which is a basic strengthening factor of the i-based alloy, to be low.

Further, in order to improve the high temperature strength, especially the long-term strength, the addition amounts of W and Mo as solid solution strengthening elements are adjusted, and the precipitation of a harmful phase which adversely affects the strength is prevented.

The gas turbine nozzle according to the present invention has nine nozzles.
Breaking strength at 00 ℃, 14kg / mm ² is 300h or more, 9
It is made of a Ni-based alloy having a specific composition that has a resistance to thermal fatigue of 00 ° C. and 350 ° C. of 600 times or more and a crack resistance of 600 times or more, and can be welded at a preheating temperature of 400 ° C. or less.

The present invention relates to the above-mentioned gas turbine in which the combustion gas combusted by the air compressed by the compressor is caused to collide with the blades respectively implanted in the plurality of disks through the nozzles to rotate the blades. The nozzles after the eyes have wings and sidewalls formed at both ends of the wings, and are arranged in a ring shape on the outer circumference of the rotating blade, and have a weight of C0.05 to 0.20.
%, Co15-25%, Cr15-25%, Al1.0
~ 3.0%, Ti1.0-3.0%, Nb1.0-3.0%
, W 5 to 10% and 55% or more of Ni are contained, and the (Al + Ti) amount and the W amount are A (Al + T) in FIG.
i2.5%, W10%), G (Al + Ti5%, W10
%), D (Al + Ti 5%, W 5%), E (Al + Ti
3.5%, W5%) and F (Al + Ti 2.5%, W7.
(5%) is preferably made of a Ni-based alloy within the line connecting the points in sequence.

In the gas turbine of the present invention, the nozzle is 9
A Ni-based preheating temperature of 400 ° C or less at which breakage does not occur in a bead formed by 1-pass TIG welding with a breaking time of 300 hours or more at 00 ° C and 14 kg / mm ² and a length of 80 mm and a width of 8 mm Alloys are preferred.

The gas turbine of the present invention is preferably a Ni-based alloy having a distance between the sidewalls at both ends of the blade of the nozzle of 70 mm or more and a length from the combustion gas inlet side to the outlet side of 100 mm or more.

The gas turbine nozzle according to the present invention comprises:
By weight, C0.05 to 0.20%, Co15 to 25%, Cr
15-25%, Al 1.0-3.0%, Ti 1.0-3.0
%, Nb 1.0 to 3.0%, W 5 to 10%, and B 0.00
1-0.03%, Hf1.5% or less, Re2% or less, V2
% Or less, Y 0.5% or less, Sc 0.5% or less and rare earth element 0.5% or less, and at least 55% Ni.
5, the amount of (Al + Ti) and the amount of W are A (Al + Ti 2.5%, W10%) and G (Al + Ti5 in FIG.
%, W10%), C (Al + Ti5%, W7.5%),
D (Al + Ti 5%, W 5%), E (Al + Ti 3.5
%, W5%) and F (Al + Ti 2.5%, W7.5%)
It is preferable that the points are within a line connecting the points.

The present invention is directed to a gas turbine driven by combustion gas flowing at a high speed, an exhaust heat recovery boiler for obtaining steam by energy of exhaust gas of the gas turbine, a steam turbine driven by the steam, and the gas turbine. And a generator driven by a steam turbine, the gas turbine has three or more blades, the turbine inlet temperature of the combustion gas is 1200 ° C. or more, and the exhaust gas temperature of the turbine outlet is 50.
0 ℃ or higher, 500 ℃ by the exhaust heat recovery boiler
With the above steam, the steam turbine comprises a rotor made of Ni-Cr-Mo low alloy steel having a high-low pressure integrated bainite structure, and a blade having a rotor that is covered with an integral casing and has a length exceeding 26 inches. In a combined power generation system characterized by having.

The role of each element contained in the Ni-base superalloy constituting the gas turbine nozzle according to the present invention will be described below.

C is solid-solved in the matrix or grain boundaries to strengthen it, improve the high temperature tensile strength, and prevent the precipitation of harmful σ phase. However, when added in excess, it promotes coarsening of carbides. It causes deterioration of strength and toughness at high temperature for a long time, and also deteriorates weldability. The addition amount is 0.05
The range of up to 0.2% is appropriate, especially 0.08 to 0.16.
% Is preferred.

Co forms a solid solution in the matrix to improve the high temperature strength and contributes to the improvement of the corrosion resistance. However, if added excessively, it promotes the precipitation of harmful intermetallic compounds and causes the deterioration of the high temperature strength. The proper addition amount is in the range of 20 to 25%.

Cr improves the corrosion resistance, but when added in excess, it causes harmful σ-phase precipitation and coarsening of carbides, which lowers the high temperature strength. Addition amount is 15-25
The range of% is appropriate, and the range of 20 to 25% is particularly preferable.

Al and Ti contribute to the high temperature strength by precipitating the γ'phase, which is a strengthening factor of the Ni-based alloy, that is, Ni ₃ (Al, Ti), but if added excessively, the weldability deteriorates.
As the addition amount, Al: 1.0 to 3.0, Ti: 1.5 to
The range of 3.0% is appropriate, especially Al + Ti: 3.0-
It is preferably 5.0%, and the atomic ratio Ti / Al is preferably in the range of 0.7 to 1.5%.

Nb, Ta and Hf form a solid solution in the γ'phase which is a strengthening factor and improve the high temperature strength, but when added in excess, they form coarse carbides at the grain boundaries and rather reduce the strength. The addition amount is Nb + Ta: 1.0 to 3.0%,
Hf: 0 to 1.5% is appropriate, especially Nb: 0.6 to
1.0% and Ta: 0.9-1.3% are preferable.

Zr and B strengthen the grain boundaries and improve the high temperature strength. However, if added excessively, the ductility and toughness deteriorate and the long-term strength decreases. The addition amount is Zr: 0 to 0.0
5% and B0.001-0.03% are appropriate.

W and Mo form a solid solution in the matrix to strengthen them, and are particularly effective in improving the long-term strength. However, if added excessively, precipitation of a harmful phase such as σ phase is promoted and the strength is rather lowered. The added amount is W + Mo:
The range of more than 5.0% and 10% or less is suitable, and W: 6.0-8.0% is particularly preferable.

Re and rare earth elements improve the high temperature corrosion resistance, but if the addition amount exceeds a certain level, the effect saturates, and rather the ductility and toughness decrease. Appropriate amount of addition is in the range of Re: 0 to 2.0% and one or more of rare earth elements such as Y and Sc: 0 to 0.5%.

Si and Mn have conventionally been effective for deoxidation, but since they are produced by vacuum casting, their addition is essentially unnecessary, but they can be added, and an excessive addition may be performed during high temperature use. Both elements are suppressed to 1% or less in order to reduce the toughness. In particular, it is 0.5% or less, more preferably 0.01
It is preferable to suppress the amount to 0.1%.

The gas turbine according to the present invention has the following configuration.

At least one of the last stage of the disc, the distant piece, the turbine spacer, the turbine stacking bolt, the compressor stacking bolt, and the compressor disc is C0.05-0.2%, S by weight.
i 0.5% or less, Mn 1% or less, Cr 8 to 13%, Ni
3% or less, Mo 1.5 to 3%, V 0.05 to 0.3%, N
It can be constituted by a heat-resistant steel having a fully tempered martensite structure in which b is 0.02 to 0.2%, N is 0.02 to 0.1%, and the balance is substantially Fe. By constructing all of these parts with this heat-resistant steel, a higher gas temperature can be obtained, and thermal efficiency can be improved. In particular, at least one of these parts is
0.05-0.2%, Si 0.5% or less, Mn 0.6% or less, Cr 8-13%, Ni 2-3%, Mo 1.5-3
%, V 0.05 to 0.3%, Nb 0.02 to 0.2%, N
0.02 to 0.1% and the balance consisting essentially of Fe,
(Mn / Ni) ratio is 0.11 or less, especially 0.04 to 0.1
When it is made of a heat-resistant steel having a total tempered martensite structure, a gas turbine having high embrittlement resistance and high safety can be obtained.

As a material used for these parts, 4
Creep rupture strength of 10 ⁵ h at 50 ° C is 40 kg / mm ² or more, and 20 ° C V-notch Charpy impact value is 5 kg-m / cm.
^Two or more martensitic steels are used, but in a particularly preferred composition, the 10 ⁵ h creep rupture strength at 450 ° C. is 50 kg / mm ² or more and 500 after 10 ⁵ h after heating for 10 ⁵ h.
It has a 0 ° C V-notch Charpy impact value of 5 kg-m / cm ² or more.

These materials further include W1% or less, Co
0.5% or less, Cu 0.5% or less, B 0.01% or less, T
i 0.5% or less, Al 0.3% or less, Zr 0.1% or less,
Hf 0.1% or less, Ca 0.01% or less, Mg 0.01%
Hereinafter, at least one of Y 0.01% or less and rare earth element 0.01% or less can be included.

At least the final stage of the compressor disk or all of it can be made of the above-mentioned heat-resistant steel. However, since the gas temperature is low from the first stage to the central portion, other low alloy steel can be used, and the central portion can be used. The heat-resistant steel described above can be used from to the final stage. The upstream side from the first stage on the upstream side of the gas to the central portion is C0.15-0.1 by weight.
30%, Si 0.5% or less, Mn 0.6% or less, Cr1-
2%, Ni 2.0-4.0%, Mo 0.5-1%, V 0.0
Ni-Cr-Mo-V having a tensile strength at room temperature of 80 kg / mm ² or more and a V-notch Charpy impact value at room temperature of 20 kg-m / cm ² or more consisting of 5 to 0.2% and the balance substantially Fe.
Steel is used, and C0.2-0.4%, Si0.1-0.5%, Mn.
5 to 1.5%, Cr 0.5 to 1.5%, Ni 0.5% or less, Mo 1.0 to 2.0%, V 0.1 to 0.3% and the balance substantially Fe, and room temperature. Having a tensile strength of 80 kg / mm ² or more, an elongation rate of 18% or more, and a drawing rate of 50% or more
-Mo-V steel can be used.

For the compressor stub shaft and the turbine stub shaft, the above-mentioned Cr-Mo-V steel can be used.

The compressor disk of the present invention is disk-shaped, and a plurality of holes for inserting stacking bolts are provided on the outer peripheral portion around the entire circumference.

As an example of the compressor disk, 17
If it consists of steps, the first to 12th steps are
-Cr-Mo-V steel, 13th to 16th steps are Cr-M
The o-V steel and the 17th stage can be constituted by the above-mentioned martensitic steel.

The first-stage and last-stage compressor disks each have a structure that is more steel than the next stage of the first stage or the last stage of the last stage when it is the first stage. Further, this disk has a structure in which the thickness is gradually reduced from the initial stage to reduce the stress due to high speed rotation.

The blades of the compressor are C0.07-0.
15%, Si 0.15% or less, Mn 1% or less, Cr10
~ 13% or less than 0.5% Mo and 0.5% Ni
It is preferably composed of martensitic steel with the balance including Fe, including the following:

The weight of the first stage portion of the shroud which is in sliding contact with the tip portion of the turbine blade and which is formed in a ring shape is C0.05 to 0.2%, Si2% or less, Mn2% or less, Cr17 to 27%, Co5% or less, Mo5-15
%, Fe 10 to 30%, W 5% or less, B 0.02% or less, and the balance is substantially Ni.
Other parts by weight are C 0.3 to 0.6%, Si 2% or less, Mn 2% or less, Cr 20 to 27%, Ni 20 to 30
%, Nb 0.1-0.5%, Ti 0.1-0.5%, and the balance being substantially Fe. These alloys are composed of a plurality of blocks in a ring shape.

In the diaphragm for fixing the turbine nozzle, the weight of the first stage turbine nozzle portion is C0.05% or less, Si1% or less, Mn2% or less, Cr16 to 22%,
Ni is 8 to 15% and the balance is substantially Fe, and the other turbine nozzle portion is made of high C-high Ni steel casting.

Turbine blades, by weight, range from C0.07
0.25%, Si 1% or less, Mn 1% or less, Cr12-
20%, Co 5-15%, Mo 1.0-5.0%, W 1.
0 to 5.0%, B 0.005 to 0.03%, Ti 2.0 to
7.0%, Al3.0-7.0%, Nb1.5% or less,
Zr 0.01-0.5%, Hf 0.01-0.5%, V0.01
A cast alloy containing at least one of 0.5% and the balance substantially Ni, and having a γ ′ phase and a γ ″ phase precipitated in the austenite matrix is used.

The gas turbine nozzle is provided with the above-mentioned Ni-based superalloy at least in the first stage, and in the other parts than the first stage, the weight is C 0.20 to 0.60%, Si 2% or less, Mn 2% or less, Cr 25 to 35%. , Ni 5-15%, W3-10
%, B 0.003 to 0.03% and Co 50% or more of a Co-based alloy, or Ti 0.1 to 0.3%,
It is composed of a cast alloy containing at least one of Nb 0.1 to 0.5% and Zr 0.1 to 0.3% and containing an eutectic carbide and a secondary carbide in an austenite phase matrix. All of these alloys are solution treated and then aged,
It forms and strengthens the aforementioned precipitates.

The turbine blade is made of Al, Cr or Al + Cr in order to prevent corrosion due to high temperature combustion gas.
Diffusion coating can be applied. The coating layer has a thickness of 30 to 150 μm, and is preferably provided on the blade portion in contact with the gas.

A plurality of combustors are provided around the turbine and have a double structure of an outer cylinder and an inner cylinder. The inner cylinder has a weight of C0.05-2.0%, Si2% or less, Mn2% or less. , Cr20-25%, Co0.5-5%, Mo5-1
5%, Fe 10-30%, W 5% or less, B 0.02% or less, and the balance consisting essentially of Ni, and is constructed by welding a plastically worked material having a plate thickness of 2 to 5 mm, and supplies air over the entire circumference of the cylindrical body. A crescent-shaped louver hole is provided, and a solution treatment material having a full austenite structure is used.

The steam turbine in the combined cycle power plant according to the present invention has the following configuration.

According to the present invention, a steam turbine comprising a rotor in which blades are planted in a multi-stage manner from a high pressure side to a low pressure side of steam on an integral rotor shaft, and a casing covering the rotor is provided with a bainite structure for the rotor shaft. Consisting of a Ni-Cr-Mo-V low alloy steel with
The creep rupture strength at 38 ° C for 100,000 hours is 11 kg / mm ² or more.

The rotor shaft has a weight of C 0.15-
0.4%, Si 0.1% or less, Mn 0.05 to 0.25
%, Ni 1.5-2.5%, Cr 0.8-2.5%, Mo
0.8 to 2.5% and V 0.1 to 0.35%, (M
Ni-C having a bainite structure in which the (n / Ni) ratio is 0.12 or less or the (Si + Mn) / Ni ratio is 0.18 or less.
Those made of r-Mo-V low alloy steel are preferred.

In this way, the steam inlet temperature is 5
30 ° C. or more, the outlet temperature thereof is 100 ° C. or less, the length of at least the final stage of the blade is 30 inches or more, and the rotor shaft has a FATT at the center thereof equal to or lower than the steam outlet temperature and 538 ° C. , A Ni-Cr-Mo-V having a bainite structure having a creep rupture strength of 100,000 hours of 11 kg / mm ² or more, particularly 12 kg / mm ² or more
It is possible to use a low alloy steel and use a blade having a size exceeding 26 inches.

Particularly, the blade has a length of 30 inches or more on the low pressure side, the blade on the high pressure side is made of high Cr martensitic steel having higher creep rupture strength than that on the low pressure side, and the blade on the low pressure side is at high pressure. A high Cr martensitic steel having higher toughness than that of the side steel is used.

The blade having a length exceeding 26 inches has a weight ratio of C 0.08 to 0.15%, Si 0.5% or less,
Mn 1.5% or less, Cr 10-13%, Mo 1-2.5%
, V0.2-0.5%, N0.02-0.1%, and the high-pressure side blade is composed of
C 0.2-0.3%, Si 0.5% or less, Mn 1% or less,
Cr 10-13%, Ni 0.5% or less, Mo 0.5-1.
5%, W0.5-1.5%, V0.15-0.35% of martensitic steel, and the low pressure side blade of less than 26 inches by weight is C0.05-0.15%, Si0. .
5% or less, Mn 1% or less, preferably 0.2 to 1.0
%, Cr 10 to 13%, Ni 0.5% or less, Mo 0.5
% Or less and the balance Fe, which consists of martensitic steel.

An erosion-preventing layer is preferably provided on the leading-edge etching portion of the 30-inch or larger blade. As a specific wing length, 33.5 "
, 40 ", 46.5" and the like can be used.

The present invention can achieve a combined power generation system in which one generator is simultaneously driven by the above-mentioned steam turbine and gas turbine, and in particular, the steam turbine has a multi-stage structure in which an integral rotor shaft extends from a high pressure side to a low pressure side of steam. A rotor having a blade planted therein, and a casing covering the rotor, the steam inlet temperature is 530 ° C. or higher and the outlet temperature is 100 ° C. or lower, and the casing extends from the high pressure side to the low pressure side of the blade. Integrally configured, a steam inlet is provided before the first stage of the blade and an outlet thereof is provided after the last stage of the blade so that the steam flows in one direction, and the blade has a length of 30 inches or more on the low pressure side. Can be

The moving blade in the present invention has a weight of C0.05.
~ 0.15%, Si 0.5% or less, Mn 0.2 ~ 1%,
It is preferable to use a tempered all-martensitic steel in which Cr is 10 to 13%, Ni is 0.5% or less, Mo is 0.5% or less, and the balance is substantially Fe. The casing of the present invention has a weight ratio of C0.05 to 0.30% and Si of 0.5% or less,
Mn 1% or less, Cr 1-2%, Mo 0.5-1.5%, V
It is preferably made of a Cr-Mo-V cast steel having a bainite structure containing 0.05 to 0.2% and Ti of 0.05% or less.

Cr-Mo-V having the composition described above.
Steel is produced by vacuum remelting the steel ingot in the atmosphere after electromelting or in an arc furnace and then vacuum carbon deoxidizing the steel ingot, hot forging the steel ingot, and then heating it to an austenitizing temperature and cooling it to a predetermined temperature. It is preferable to perform quenching after cooling at a speed and then to perform tempering to obtain a bainite structure.

The quenching temperature is preferably 900 to 1000 ° C, and the tempering temperature is preferably 630 to 700 ° C.

The steam turbine according to the present invention is especially 10 to 3
It is most suitable for medium-capacity thermal power generation of 0,000 KW class and is suitable from the viewpoint of improving thermal efficiency. Especially, the longest wing has a length of 33.
It can be 5 inches and have 90 or more perimeters.

[0057]

BEST MODE FOR CARRYING OUT THE INVENTION

Example 1 Table 1 shows the chemical composition (wt%) of a typical gas turbine nozzle match. Each sample was agglomerated in a high-frequency melting furnace in an amount of 10 kg, subjected to a lost wax precision structure, heated at 1170 ° C. for 4 hours, cooled with water, and subjected to an aging treatment at 850 ° C. for 8 hours.
Then, a test piece was prepared by machining. No. 1, 2,
12, 14, 15 and 17 are comparative alloys, No. 3 to 1
1, 13 and 16 are alloys of the present invention.

[0058]

[Table 1]

FIG. 1 shows the creep rupture strength at 900 ° C. The test piece used had a parallel portion of 6 mmφ and a length of 30 mm. The alloys of the present invention Nos. 3 to 6 have improved creep rupture strength on the long time side as compared with the comparative alloys No. 2 and No. 12, and solid solution strengthening of W or Mo or addition of Zr, Hf (No. 6). )
The effect of is remarkable. On the other hand, comparative alloy No. 1 with a lower W
1 has a small improvement effect.

FIG. 2 shows the relationship between Al + Ti and the weld crack length when performing 1-pass TIG welding at a preheating temperature of 250 ° C. or less, a welding current of 40 to 80 A, and a welding time of 50 seconds. Welded with a welding length of 80 mm and a width of 8 mm. High Al + Ti No. 14
Has a large amount of γ ′, so cracks easily occur during welding cooling. An alloy in which Al + Ti is suppressed to a low level has small welding cracks, and sound welding is possible depending on the welding conditions. Due to the effect of welding cracks, Al + Ti is preferably suppressed to 5.0% or less. Although the strength is increased by adding W, the weldability is hardly affected.

FIG. 3 shows Al + Ti at 900 ° C. and 14 kgf.
It shows the relationship between the creep rupture time of / mm ² .
The strength increases in proportion to the Al + Ti content of 2.5% or more. However, considering welding cracks as shown in FIG. 2, the amount of Al + Ti is preferably 5.0% or more,
From the results of FIG. 3, it is necessary to add 2.5% or more in terms of strength. However, it is possible to reduce the amount of Al + Ti to 2.5% by adjusting the relationship between the amount of Al + Ti and the amount of W shown in FIG. As shown in the figure, it can be seen that the influence of the amount of Al + Ti has a completely different effect depending on the amount of W. When the W amount is around 7 to 9%, the strength is rapidly increased when the Al + Ti amount is 2.5% or more, and the greatest effect is obtained when the W amount is 3 to 5%, but when the W amount is 5.5 to 7%, the Al + Ti amount is increased. The effect of is improving the strength up to around 5%. Therefore,
High strength can be obtained by increasing the amount of W without increasing the amount of Al + Ti.

Similarly, FIG. 4 is a diagram showing the relationship between the creep rupture time and the W content. As shown in the figure, the amount of W is 5.5-
It can be seen that the maximum effect can be obtained by setting the range to 10%. It can be seen that it is particularly remarkable when the amount of Al + Ti is 3 to 5%. Especially, the W amount is 6
Most preferably, it is set to ~ 8.5%.

FIG. 5 shows the relationship between Al + Ti and W and 900.
The creep rupture time at 12 ° C and 12 kgf / mm ² is shown in parentheses. The shaded area is 5 <W ≦ 10, 2.5 ≦ Al + Ti ≦ 5.
0, -2.5 (Al + Ti) + 13.75 <W ≤ -2.5
The range of (Al + Ti) +13.75 is shown. Among the alloys of the present invention in the shaded area, No. 3 and No. 4 show particularly high strength, and W and Al + Ti with respect to creep rupture strength.
There is a correlation between. That is, the experimental results so far show that it is possible to improve weldability by reducing the amount of Al + Ti, and to supplement the decrease in strength by adding W.

FIG. 6 shows the number of crack initiations when a heating / cooling heat cycle of 900 ° C. holding 30 minutes → 300 ° C. was applied.
The thermal fatigue resistance is greatly improved compared with the conventional Co-based alloy of Comparative Alloy No. 17. Further, even Ni-based alloys exhibit higher thermal fatigue resistance than comparative alloys No. 2 and No. 13 having low high-temperature strength. This indicates that the thermal fatigue resistance has a correlation with the strength, and the influence of the addition amounts of Al, Ti, and W which are the strengthening elements appears.

Example 2 Using the alloy No. 7 shown in Table 1 of Example 1, a gas turbine nozzle shown in FIG. 7 was manufactured. A wax model having the shape shown in FIG. 7 is dipped in a solution of acrylic resin dissolved in methyl ethyl ketone, dried by ventilation, and then dipped in a slurry (zircon flower + colloidal silica + alcohol) (first layer zircon sand, chamoitte after 2 layers). Sand) was sprayed and this was repeated several times to form a mold. The mold was dewaxed and then fired at 900 ° C.

Next, this mold was provided in a vacuum furnace, and a No. 7 alloy composition was melted by vacuum melting and cast into a mold in vacuum. This nozzle is a casting with a width of the blade between the sidewalls of about 74 mm, a length of 110 mm, the thickest part of 25 mm, a wall thickness of 3-4 mm, and an air passage slit of about 0.7 mm at the tip. Is.

FIG. 8 is a perspective view in which a part of the blade is cut, and holes for pin fin cooling, impingement cooling and film cooling are provided. The thickness of the slit at the tip is about 1
mm. The obtained nozzle is subjected to solution treatment and aging treatment in a non-oxidizing atmosphere in the same manner as described above.

The nozzle of this embodiment is most suitable for the first stage, but it can be provided for the second and third stages, but the second and third stages are made of a Co-based alloy, which will be described later. A nozzle composed of wings is provided. Both ends of the first-stage nozzle are constrained, but the second and third stages are constrained on one side. The blade width of the second and third stages is larger than that of the first stage.

A SUS304 stainless steel tube having impingement cooling holes is TIG-welded all around the body, and cooling air is introduced from that portion as shown in FIG. 8 so that no air leaks from the welded portion. As shown in FIG. 7, a hole through which cooling air flows is also provided inside the combustion gas outlet side.

The first-stage nozzle has a structure in which it is constrained at both ends of the sidewall, but the second-stage and subsequent stages have a structure in which it is constrained at one side on the outer peripheral side of the sidewall.

In the nozzle made of the Ni-based alloy in this example, the γ'phase was precipitated in the γ-phase matrix.

Embodiment 3 FIG. 9 is a partial sectional view of a rotating portion of a gas turbine having a gas turbine nozzle of the present invention according to Embodiment 2.

10 is a turbine stub shaft, 3 is a turbine blade, 13 is a turbine stacking bolt, 1
8 is a turbine spacer, 18 is a distant piece, 2
0 is a nozzle, 6 is a compressor disk, 7 is a compressor blade, 8 is a compressor stacking bolt,
Reference numeral 9 is a compressor stub shaft, 4 is a turbine disk, and 11 is a hole. The gas turbine of the present invention has 17 stages of compressor disks 6 and 2 stages of turbine blades 3. The turbine blade 3 may have three stages, and the alloy of the present invention can be applied to any of them as a nozzle material.

The gas turbine in this embodiment is mainly composed of a heavy tuty type, a single shaft type, a horizontal split casing, a stacking type rotor, a compressor is a 17-stage axial flow type, and a turbine is a 3-stage impulse type. The two-stage air-cooled stationary blades and combustor have a verse-flow type, 16 cans, and a slot cool system.

With respect to the materials shown in Table 2, large-sized steels corresponding to actual products were melted by the electroslag remelting method, and forged and heat-treated. Forging was performed in the temperature range of 850 to 1150 ° C., and heat treatment was performed under the conditions shown in Table 4. Table 2 shows the chemical composition (% by weight) of the sample. Regarding the microscopic structure of these materials, No. 20 to 23 are fully tempered martensite structures, N
Nos. 24 and 25 had a fully tempered bainite structure. N
The o.20 is used for the distant piece and the final stage compressor disk. The former is 60 mm thick × 500 mm wide × 1000 mm long, the latter is 1000 mm in diameter, 180 mm thick, N
o.21 is a disk with a diameter of 1000 mm and a thickness of 180 mm
No.22 is a spacer with an outer diameter of 1000 mm and an inner diameter of 400.
mm, thickness 100 mm, No. 23 is 40 mm in diameter, 500 mm in length, and No. 23 steel is used as stacking bolts for both turbine and compressor, and bolts for connecting the distant piece and the compressor disk are also manufactured. . Nos. 24 and 25 have a diameter of 250 as a turbine stub shaft and a compressor stub shaft, respectively.
mm × 300 mm in length. Furthermore, No. 24 alloy is used for 13 to 16 stages of the compressor disk 6, and No. 24 alloy is used.
Twenty-five steels were used from the first stage to the 12th stage of the compressor 6. Each of these was manufactured in the same size as the turbine disk. After heat treatment, the test piece was sampled in the direction perpendicular to the axial (longitudinal) direction except for No. 23 from the center of the sample. In this example, test pieces were taken in the longitudinal direction.

[0076]

[Table 2]

Table 3 shows the results of the room temperature tensile test, the 20 ° C. V-notch Charpy impact test and the creep rupture test. The creep rupture strength at 450 ° C. × 10 ⁵ h was obtained by the commonly used Larson-Miller method.

[0078]

[Table 3]

Looking at Nos. 20 to 23 (12Cr steel) of the present invention, the creep rupture strength at 450 ° C. and 10 ⁵ h is 51 kg.
/ Mm ² or more, 20 ° C V-notch Charpy impact value is 7kg-
It was confirmed that it was m / cm ² or more, and the strength required as a material for a high temperature gas turbine was sufficiently satisfied.

Next, stub shaft Nos. 24 and 25
(Low alloy steel) has low creep rupture strength at 450 ° C,
Tensile strength is 86kg / mm ² or more, 20 ° CV Notch Charpy impact value is 7kg-m / cm ² or more, and the strength required as a stub shaft (tensile strength ≧ 81kg / mm ² , 20 ° CV
It was confirmed that the notch Charpy impact value ≧ 5 kg-m / cm ² ) was sufficiently satisfied.

Under these conditions, the temperature of the distant piece and the temperature of the compressor disk at the final stage are 450 ° C. at maximum. The former is 25 to 30 mm and the latter is 40
A wall thickness of ~ 70 mm is preferred. A through hole is provided at the center of both the turbine and the compressor disk. Compressive residual stress is formed in the through hole of the turbine disk.

Further, in the gas turbine of the present invention, the heat-resistant steel shown in Table 4 above is used in the final stage of the turbine spacer 4, the distant piece 5 and the compressor disk 6, and other parts are made of the same steel as above. As a result, the compression ratio is 14.7, the temperature is 350 ° C or higher, the compression efficiency is 86 or higher, and the gas temperature at the inlet of the first stage nozzle is 1200 ° C.
The thermal efficiency of 2% or more is obtained, and as described above, the creep rupture strength and the high impact value after heat embrittlement are obtained, and a more reliable gas turbine can be obtained.

[0083]

[Table 4]

The turbine disk 10 has three stages,
Central holes 11 are provided in the first and second stages from the upstream side of the gas flow. In each of the examples, the heat-resistant steels shown in Table 4 were used. Further, in the present embodiment, the final stage, the distant piece 19, the turbine spacer 18, the downstream side of the gas flow of the compressor disk 6,
The turbine stacking bolt 13 and the compressor stacking bolt 8 are made of heat resistant steel shown in Table 5. Other turbine blades 3, turbine nozzles 1
4, the liner 17, the compressor blade 7, the compressor nozzle 16, the diaphragm 18, and the shroud 19 of the combustor 15 are made of alloys shown in Table 5. In particular, the turbine nozzle 12 and the turbine blade 2 are made of cast metal.

The shroud segment (1) is used in the first stage on the gas upstream side, and (2) is used in the second and third stages.

[0086]

[Table 5]

Y ₂ is formed on the outer surface of the liner, the rotor blade and the stator blade.
The thermal barrier coating layer of the O ₃ -stabilized zirconia sprayed layer is provided at the portion in contact with the flame. In particular, A12-5% by weight and Cr20-30 by weight between the base metal and the coating layer.
%, Y 0.1 to 1% and the balance Ni or Ni + Co alloy layer is provided.

With the above structure, a compression ratio of 14.7, a temperature of 250 ° C. or higher, a compression efficiency of 86% or higher, a gas temperature of the first stage turbine nozzle inlet of 1260 ° C. and an exhaust temperature of 530 ° C. are possible, and a thermal efficiency of 32% or higher is achieved. In addition to being obtained, the turbine disc, the distant piece, the spacer, the final stage of the compressor disc, and the stacking bolt are made of heat-resistant steel with high creep rupture strength and little heat embrittlement as described above. High, the turbine nozzle has high high temperature strength and high ductility, and the combustor liner also uses an alloy with high high temperature strength and fatigue resistance, which results in a more reliable and balanced gas turbine overall. It is a thing.

As the fuel used, natural gas and light oil are used.

Most gas turbines have an intercooler, but the present invention is particularly suitable for those without an intercooler because the nozzles will be hotter. The turbine nozzle in this embodiment has four stages at the first stage all around.
It is provided around 0.

Fourth Embodiment FIG. 10 is a schematic diagram showing a single-shaft combined cycle power generation system using the gas turbine of the third embodiment and used together with a steam turbine.

When generating electricity using a gas turbine,
In recent years, a gas turbine is driven by using liquefied natural gas (LNG) as a fuel, and a steam turbine is driven by steam obtained by recovering exhaust gas energy of the gas turbine, and a generator is driven by the steam turbine and the gas turbine. There is a tendency to adopt the so-called combined power generation method.
When this combined power generation system is adopted, it is possible to significantly improve the thermal efficiency to about 44% as compared with the thermal efficiency of 40% in the case of the conventional steam turbine alone.

In such a combined cycle power plant, recently, the operation of the plant has been further facilitated by the dual use of the liquefied natural gas (LNG) exclusive combustion and the liquefied petroleum gas (LPG) and the co-firing of LNG and LPG. ， It is intended to improve the economic efficiency.

First, air enters the air compressor of the gas turbine through the intake filter and the intake siren, and the air compressor
Compress air and send compressed air to a low NOx combustor.

In the combustor, fuel is injected into the compressed air and burned to produce a high temperature gas of 1200 ° C. or higher. This high temperature gas works in the turbine to generate power.

Exhaust gas of 500 ° C. or higher discharged from the turbine is sent to the exhaust heat recovery boiler through the exhaust silencer.
The heat energy in the exhaust gas of the gas turbine is recovered to generate high-pressure steam at 500 ° C. or higher. This boiler is provided with a denitration device by dry ammonia catalytic reduction. Exhaust gas is exhausted to the outside from a stack of several tripods with a length of several hundred meters.

The generated high-pressure and low-pressure steam is sent to a steam turbine composed of a high-low pressure integral rotor. Steam turbines are shown below.

Further, the steam exiting the steam turbine flows into the condenser, is vacuum deaerated and becomes condensate, and the condensate is boosted by the condensate pump to be supplied to the boiler. Then, the gas turbine and the steam turbine respectively drive a generator from both shaft ends thereof to generate electric power. For cooling a gas turbine blade using such combined power generation, steam used in a steam turbine may be used as a cooling medium. Generally, air is used as a cooling medium for the blades, but steam has a significantly larger specific heat than air and has a large cooling effect because of its light weight. If the steam used for cooling is released into the mainstream gas due to its large specific heat, the temperature of the mainstream gas will drop drastically and the efficiency of the entire plant will be reduced.
Of steam) is supplied from the cooling medium supply port of the gas turbine blade, and the blade body is cooled and heat-exchanged to a relatively high temperature (for example, about 900 ° C.) to recover the cooling medium and return it to the steam turbine. The mainstream gas temperature (about 1300 ℃
˜1500 ° C.) and the efficiency of the steam turbine, and thus the efficiency of the entire plant can be improved. With this combined power generation system, the gas turbine has approximately 40,000 kW, and the steam turbine has 60,000 kW.
Since a total power generation of W of 100,000 kW can be obtained, and the steam turbine in this embodiment is compact,
Compared to a large steam turbine, it can be economically manufactured for the same power generation capacity, and has the great advantage of being able to operate economically with fluctuations in the amount of power generation.

In the gas turbine, the air compressed by the compressor is sent to the combustor, and the combustion gas temperature is 1100 ° C.
The disk is burned at the above high temperature and the combustion gas is used to rotate the disk in which the blade is implanted.

FIG. 11 is a partial cross-sectional view of the high / low pressure integrated steam turbine according to the present invention. Conventional steam conditions for the main steam inlet are: for a steam turbine that consumes a pressure of 80 atg, a high temperature and high pressure of 480 ° C to a low pressure and low pressure of 722 mmHg and a temperature of 33 ° C in the exhaust section with a single turbine rotor,
By increasing the steam pressure at the main steam inlet of this high-low pressure integrated steam turbine to 100 atg and the temperature to 536 ° C., the single-unit output of the turbine can be increased. Increasing the single machine output requires increasing the blade length of the final stage rotor blade and increasing the steam flow rate. For example, if the blade length of the final stage rotor blade is changed from 26 inches to 33.5 inches, the annulus area will increase by about 1.7 times. Therefore, conventional output 100MW to 170M
If the blade length is further increased to 40 inches for W, the single machine output can be more than doubled.

When Cr-Mo-V steel containing 0.5% Ni was used for the high-low pressure integral rotor as the rotor shaft material having a length of 33.5 inches or more, the rotor material originally had a high temperature range. Since it has excellent high temperature strength and creep characteristics, it can sufficiently cope with an increase in steam pressure and temperature at the main steam inlet. Low temperature area,
In particular, in the turbine rotor center hole of the final stage rotor blade, the tangential stress generated in the rated rotation state is about 0.95 in terms of stress ratio (working stress / allowable stress) in the case of a 26-inch long blade. In the case of a 0.5-inch long wing, it is about 1.1,
It cannot be used.

On the other hand, when 3.5% Ni-Cr-Mo-V steel is used, this rotor material is a material having toughness in the low temperature region and at a lower temperature than Cr-Mo-V steel. Since the tensile strength and proof stress in the range are about 14% higher, 33.5
Even if an inch long blade is used, the above stress ratio is about 0.96.
Is. When a 40-inch long blade is used, the above stress ratio is 1.07, which is not usable. In the high temperature range, the creep rupture stress is about 0.3 times that of Cr-Mo-V steel, so the high temperature strength becomes insufficient and it cannot be used.

In order to increase the output in this way, Cr-Mo-V steel is used in the high temperature range and Ni-Cr-M is used in the low temperature range.
There is a need for a rotor material that combines the excellent properties of o-V steel. When using long blades in the 30-inch to 40-inch class, the conventional Ni-Cr-Mo-V steel (ASTMA470class
In 7), since the stress ratio is 1.07 as described above,
A material with a tensile strength of 88 kg / mm ² or more is required.

Further, as a high / low pressure integrated steam turbine rotor material to which long blades of 30 inches or more are attached, from the viewpoint of ensuring stability against high temperature destruction on the high pressure side, 538 ° C., 10 ⁵
h A material having a creep rupture strength of 15 kg / mm ² or more and a room temperature impact absorption energy of 2.5 kg-m (3 kg-m / cm ² ) or more is required from the viewpoint of ensuring safety against destructive fracture on the low pressure side.

From such a point of view, the heat-resistant steel according to the present invention can be obtained that satisfies the above-mentioned characteristics, and as described above, high output can be achieved with a single machine output.

The steam turbine according to the present invention is provided with 13 stages of blades 24 which are planted on the high and low pressure integrated rotor shaft 23. The steam passes through the steam control valve 25 and flows from the steam inlet 21 to 538 ° C. as described above. It flows in at a high temperature and high pressure of 88 atg. The steam flows in one direction from the inlet 21,
The steam temperature is 33 ° C. and 722 mmHg is reached, and the blade 24 at the final stage is discharged from the outlet 22. The high and low pressure one-piece rotor shaft 23 according to the present invention is 538 ° C steam to 33 ° C
Since it is exposed to the temperature of
Forged steel of -Mo-V low alloy steel is used. The blade 24 of the rotor shaft 23 has a disk-shaped embedded portion, and is manufactured by being integrally cut from the rotor shaft 23. The shorter the length of the blade, the longer the length of the disk portion, so that vibration is reduced.

[0107]

[Table 6]

The rotor shaft 23 according to the present invention was produced by forging alloy compositions shown in Table 6 by remelting electroslag, forging it to a diameter of 1.2 m, heating it at 950 ° C. for 10 hours, and then holding it at the center. Water spray cooling was performed while rotating the shaft so as to be 100 ° C./h. Then 6
Tempering was performed by heating at 65 ° C. for 40 hours. A test piece was cut out from the center of the rotor shaft, and a creep rupture test, a V-notch impact test before and after heating (after heating at 500 ° C. for 3000 hours) (cross-sectional area of the test piece 0.8 cm ² ) and a tensile test were performed.

The material composition of each part in this example is as follows.

(1) Blade The length of the three stages on the high temperature and high pressure side is about 40 mm, and the weight is C0.2.
0 to 0.30%, Cr 10 to 13%, Mo 0.5 to 1.5
%, W0.5-1.5%, V0.1-0.3%, Si0.5
% Mar, 1% Mn or less, and the balance Fe.

The length of the medium-pressure portion gradually increases toward the low-pressure side, and C0.05-0.15% by weight, Mn1
% Or less, Si 0.5% or less, Cr 10 to 13%, Mo 0.5.
It was constructed by forging a martensitic steel consisting of 5% or less, Ni 0.5% or less, and the balance Fe.

As the final stage, with a length of 33.5 inches,
There are about 90 pieces per turn, C0.08 to 0.15% by weight, Mn
1% or less, Si 0.5% or less, Cr 10-13%, Ni
1.5-3.5%, Mo1-2%, V0.2-0.5%,
It was constructed by forging a martensitic steel consisting of N 0.02 to 0.08% and the balance Fe. In addition, a shield plate made of a stellite plate for preventing erosion is provided at the leading end at the leading edge portion by welding at the final stage. In addition to the shield plate, it is partially quenched. In addition, A15 to 7 for 40 inches or longer
%, V3-5% Ti blade is used.

Four to five blades are fixed in each stage by a shroud plate made of the same material by caulking a projection tenon provided at the tip thereof.

At 3000 rpm, the above-mentioned 12% Cr steel is used even in the length of 40 inches, and at 3600 rpm, the Ti blade is used at 40 inches, but 12% Cr steel is used up to 33.5 inches.

(2) For the stationary blade 27, martensite steel having the same composition as that of the moving blade is used up to a high pressure of three stages, but otherwise, the same material as the moving blade material for the above-mentioned intermediate pressure portion is used. .

(3) The casing 26 has a weight of C0.
15-0.3%, Si 0.5% or less, Mn 1% or less, C
r1-2%, Mo0.5-1.5%, V0.05-0.2
%, Ti 0.1% or less Cr-Mo-V cast steel is used. 28 is a generator and 10-20 by this generator
It can generate 10,000 kW. The distance between the bearings 32 of the rotor shaft in this embodiment is about 520 cm, and the outer diameter of the final stage blade is 316 cm, and the axial ratio to this outer diameter is 1.
65. A power generation capacity of 100,000 kW is possible. The length between these bearings is 0.52 per 10,000 kW of power output.
m.

In this embodiment, the outer diameter is 365 cm when the final stage blade is 40 inches, and the bearing-to-bearing ratio to the outer diameter is 1.43. As a result, a power generation output of 200,000 KW is possible, and the bearing distance per 10,000 KW is 0.26 m.

The ratio of the outer diameter of the blade-implanted portion of the rotor shaft to the length of these final stage blades is 33.
1.70 for 5 "blade and 1.7 for 40" blade
It is 1.

In this embodiment, the steam temperature can be set to 566 ° C. and the pressure can be set to 121, 169 and 224 atg.

The construction of the plant was one series consisting of six sets of one power generation system each consisting of a gas turbine, an exhaust heat recovery boiler, a steam turbine and a generator.

In the gas turbine, air was compressed and LNG was burned therein to generate high temperature combustion gas. The turbine was rotated and directly connected to drive the generator.

In the exhaust heat recovery boiler, the heat of the combustion gas emitted from the gas turbine is effectively recovered to generate steam, which is then guided to the steam turbine to drive the generator directly connected to it.

Regarding the ratio of the power generation output, about 2/3 was shared by the gas turbine, and the remaining about 1/3 was shared by the steam turbine.

The above-described combined power generation system has the following effects.

The thermal efficiency is 2-3% higher than that of conventional thermal power generation. Also, by reducing the number of operating gas turbines even under partial load, the operating equipment can be operated near the rated load with high thermal efficiency, so that high thermal efficiency as a whole plant could be maintained.

The combined power generation is composed of a combination of a gas turbine, which can be started and stopped easily in a short time, and a small, simple steam turbine. Therefore, the output can be easily adjusted and the intermediate load that responds quickly to changes in demand. Best for firepower.

The reliability of the gas turbine has dramatically increased due to the recent technological development. Further, since the combined power generation plant constitutes a system with a combination of medium-capacity machines, a failure should occur. Even so, the effect can be limited to local areas, and it is a highly reliable power source.

Since the output shared by the steam turbine of combined power generation is as small as about one-third of the entire plant, the amount of hot waste water is about 70% of the conventional steam power of the same capacity.

[0129]

As described above, according to the present invention,
A Ni-based alloy that has superior heat fatigue resistance to conventional Co-based alloys, higher strength than conventional Ni-based alloys for a long time, and excellent weldability is obtained. Suitable for gas turbine nozzle materials that require
High reliability is obtained in gas turbines and combined cycle power plants.

[Brief description of drawings]

FIG. 1 Creep rupture strength at 900 ° C., that is, stress-
The figure which shows a breaking time curve.

FIG. 2 is a diagram showing the relationship between the amount of Al + Ti and the weld crack length.

FIG. 3 is a diagram showing the relationship between the amount of Al + Ti and the creep rupture time at 900 ° C. and 14 kgf / mm ² .

FIG. 4 is a diagram showing the relationship between W amount and creep rupture time.

FIG. 5: Relation between W and Al + Ti, 900 ° C., 12 kgf / m
A diagram showing the creep rupture time of m ² .

FIG. 6 is a diagram showing the number of crack occurrences when a heating / cooling cycle of 900 ° C. holding 30 minutes → 300 ° C. is given.

FIG. 7 is a perspective view of a gas turbine nozzle according to the present invention.

8 is a perspective view of the wing portion of FIG. 7. FIG.

FIG. 9 is a sectional view of a gas turbine according to the present invention.

FIG. 10 is a configuration diagram showing a combined power generation system.

FIG. 11 is a cross-sectional view of a steam turbine having a high-low pressure integrated rotor shaft.

[Explanation of symbols]

3 ... Blade for gas turbine, 4 ... Disk for gas turbine, 20 ... Nozzle for gas turbine, 23 ... High and low pressure integrated rotor shaft.

Front page continuation (72) Inventor Hiroshi Fukui 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd.

Claims (10)

[Claims] 1. A gas turbine in which combustion gas combusted by air compressed by a compressor is collided through blades with blades respectively implanted in three or more stages of disks to rotate the blades, the nozzles have blades. And sidewalls formed at both ends of the blade, which are arranged in a ring shape on the outer circumference of the rotating blade, and the initial stage on the combustion gas inlet side has a weight of C0.05 to 0.20.
%, Co 20-25%, Cr 15-25%, Al 1.0
~ 3.0%, Ti 1.0-3.0%, Nb 1.0-3.0%,
It is composed of a Ni-based alloy containing 5 to 10% W and 55% or more Ni, and the second and subsequent stages are C0.2 to 0.6% by weight, Si 2% or less, Mn 2% or less, Cr 25 to 35%, Ni 5 to 15
%, W3 to 10%, B0.003 to 0.03% and Co5
A gas turbine comprising a Co-based alloy having 0% or more. 2. The gas turbine according to claim 1, wherein the gas turbine is provided with a plurality of nozzles of at least three stages exposed to combustion gas and a plurality of blades of at least three stages implanted in a rotor. So, C 0.07 to 0.25
%, Si 1% or less, Mn 1% or less, Cr 12 to 20%,
Co5-15%, Mo1-5%, W1-5%, B0.0
05-0.03%, Ti2-7%, Al3-7%, Nb
A gas turbine characterized by having a Ni content of 1.5% or less, Zr 0.01 to 0.5% and 50% or more, and being composed of a Ni-base cast alloy having a γ'phase and a γ "phase. 3. The gas turbine according to claim 1, further comprising a plurality of nozzles exposed to combustion gas in at least three stages, and a plurality of blades respectively implanted in the discs in at least three stages. 450 ° C, 10 ⁵ h
A gas turbine characterized by comprising martensitic steel having a creep rupture strength of 40 kg / mm ² or more. 4. The gas turbine according to claim 1, further comprising at least three stages of blades exposed to the combustion gas, and a shroud arranged in a ring shape so as to face the blade tips. In the shroud, the weight of the portion facing the first stage of the blade is C0.05-
0.2%, Si 2% or less, Mn 2% or less, Cr 17 to 2
7%, Co 5% or less, Mo 5-15%, W 5% or less, B
It is composed of a Ni-based alloy having 0.02% or less and Fe10 to 30%, and the weight is C0.3 to 0.6%, Si2% or less, Mn2% or less, Cr20 except for the portion facing the first stage. ~ 27%, Ni20 ~ 30%, Nb0.1
Gas turbine, characterized in that it is constituted by an Fe-based alloy with 0.5% Ti and 0.1-0.5% Ti. 5. The gas turbine according to claim 1, wherein an Al or Cr diffusion coating layer is provided on at least the blade surface of the blade after the third stage. 6. A combustion gas combusted by air compressed by a compressor is collided through a nozzle with a blade implanted in each of a plurality of disks to rotate the blade. In the gas turbine, the nozzle has a blade portion and sidewalls formed at both ends of the blade portion, and is arranged in a ring shape on the outer circumference of the rotating blade, and has a weight of C0.05 to 0.2.
0%, Co15-25%, Cr15-25%, Al1.
0-3.0%, Ti 1.0-3.0%, Nb 1.0-3.0
%, W 5 to 10% and 55% or more of Ni, and the (Al + Ti) amount and the W amount are A (Al +
Ti2.5%, W10%), G (Al + Ti5%, W1
0%), D (Al + Ti 5%, W 5%), E (Al + T
i3.5%, W5%) and F (Al + Ti2.5%, W
(7.5%) is a gas turbine characterized by being made of a Ni-base superalloy within the line that sequentially connects the points. 7. A combustion gas combusted by air compressed by a compressor is collided through a nozzle with blades respectively implanted in a plurality of disks to rotate the blades. In the gas turbine, the nozzle has a blade portion and sidewalls formed at both ends of the blade portion, and is arranged in a ring shape on the outer periphery of the rotating blade, and is 900 ° C., 14 kg / mm ²
Break time at 300 hours or more, length 80mm, width 8mm
A gas turbine made of a Ni-based alloy having a preheating temperature of 400 ° C. or lower in which a bead formed by 1-pass TIG welding does not crack. 8. A combustion gas combusted by air compressed by a compressor is caused to collide with blades respectively implanted in a plurality of disks through a nozzle to rotate the blades. In the gas turbine, the nozzle has a blade portion and sidewalls formed at both ends of the blade portion, and is arranged in a ring shape on the outer periphery of the rotating blade, and the blade portion has a space between the sidewalls at both ends. A gas turbine, which is made of a Ni-base superalloy having a length of 70 mm or more and a combustion gas inlet side to an outlet side of 100 mm or more. 9. The method according to claim 1, wherein the combustion gas combusted by the air compressed by the compressor is caused to collide with the blades implanted in the plurality of disks through the nozzle to rotate the blades. In the gas turbine, the nozzle has a blade portion and sidewalls formed at both ends of the blade portion, and is arranged in a ring shape on the outer circumference of the rotating blade, and has a weight of C0.05 to 0.2.
0%, Co15-25%, Cr15-25%, Al1.
0-3.0%, Ti 1.0-3.0%, Nb 1.0-3.0
%, W5-10%, B0.001-0.03%, Hf
1.5% or less, Re2% or less, V2% or less, Y0.5% or less, Sc0.5% or less and at least one kind of rare earth element 0.5% or less, and the balance is substantially Ni. ,
In FIG. 5, the amount of (Al + Ti) and W are A (Al
+ Ti 2.5%, W 10%), G (Al + Ti 5%, W
10%), D (Al + Ti 5%, W 5%), E (Al +
Ti3.5%, W5%) and F (Al + Ti2.5%,
(W 7.5%) A gas turbine characterized by being within a line that sequentially connects the points. 10. A gas turbine driven by combustion gas flowing at high speed, an exhaust heat recovery boiler for obtaining steam by energy of exhaust gas of the gas turbine, a steam turbine driven by the steam, the gas turbine and steam. In a combined power generation plant including a generator driven by a turbine, the gas turbine has three or more blades and the combustion gas has a turbine inlet temperature of 12 or more.
The temperature of the exhaust gas at the turbine outlet is 00 ° C or higher, the temperature of the exhaust gas at the turbine outlet is 500 ° C or higher, and the exhaust heat recovery boiler converts the steam into steam of 500 ° C or higher. And a rotor, which is covered with an integral casing,
A combined power generation system having a blade having a length exceeding 26 inches.