Abstract: It is intended to effectively cool a dummy ring and a rotor disposed on the inner side of the dummy ring of a single-flow turbine and to suppress a decrease in thermal efficiency by preventing main steam from leaking to the dummy ring side. A cooling steam supply pipe 32 is provided in the dummy ring 26 of the single-flow turbine 10A and extraction steam of a boiler at 570° C. or below is supplied to a clearance c between the dummy ring 26 and the turbine rotor 12 as cooling steam S4. The cooling steam S4 has lower temperature and higher pressure than leak steam S2 which is a portion of the main steam S1 leaking to the dummy ring 26 side. By supplying the cooling steam S4, the leak steam S2 is prevented from entering the dummy ring 26 side and the dummy ring 26, a welding part w and a second rotor part 12b with low heat resistance that are disposed on the inner side of the dummy ring 26 can be cooled.

Abstract: There are provided a turbine rotor having suitable strength and toughness without causing soaring manufacturing costs and prolonged manufacturing time, and a manufacturing method of the turbine rotor. In a turbine rotor constructed by welding a rotor member for high temperature made of high Cr steel, and a rotor member for low temperature made of low Cr steel, the high temperature rotor member is formed from high Cr steel of which the nitrogen content is 0.02% or higher by mass %, and a filler material which welds the high temperature rotor member and the low temperature rotor member together is a 9% Cr-based filler material of which the nitrogen content is 0.025% or lower by mass %.

Abstract: Disclosed is a welding material for a Ni-based alloy, comprising components expressed as follows: C?0.05 mass %; 8 mass %?Cr?25 mass %; Fe?4.0 mass %; W?15 mass %; 5 mass %?Mo+½(W+Re)?20 mass %; Co?20 mass %; 0.01 mass %?Al<2.0 mass %; 0.01 mass %?Ti<2.0 mass %; Al+½Ti?3.0 mass %; Nb+½Ta?1.5 mass %; B?0.007 mass %; Zr?0.04 mass %; 0.01 mass %?Si?0.5 mass %; Mn?1.0 mass %; P?0.010 mass %; S?0.002 mass %; O?0.005 mass %; and Ni and unavoidable impurities which constitute the balance.

Abstract: There are provided an Ni-based alloy high-chrome steel structure and its manufacturing method capable of joining Ni-based alloys and high-chrome steels by welding, and performing suitable heat treatment, thereby maintaining the strength in the joints.

Abstract: A seal structure that is capable of actively controlling the actuation of a movable seal ring, enhancing sealing performance, and enhancing reliability, is provided.

Abstract: Provided is a steam turbine facility capable of suppressing the possibility of vibration occurrence and a drastic increase in facility cost, thereby realizing an increase in size of the facility, even if steam conditions of 650° C. or higher are adopted.

Abstract: A turbine rotor which is composed by connecting Ni-based alloy and heat resisting steel such as 12-Cr steel by welding to be able to ensure strength of welded parts and can be used under steam conditions of 700° C. class and method of manufacturing the rotor are also provided. The rotor of the rotating machine into which working fluid of 650° C. or higher is introduced, the rotor being composed of a plurality of members connected by welding such that material of each member is different in accordance with temperature of working fluid which flows contacting the members, wherein the first member(s) is formed from Ni-based alloy having mean linear expansion coefficient of 12.4×10?6/° C.˜14.5×10?6/° C., preferably 14.0×10?6/° C. or smaller within a temperature range from a room temperature to 700° C. and second member(s) is formed from high-chrome steels, and the rotor is composed such that the first member(s) formed from Ni-base alloy is located in a portion which contact to the working fluid of 650° C.

Abstract: Provided is a steam turbine facility capable of suppressing the possibility of vibration occurrence and a drastic increase in facility cost, thereby realizing an increase in size of the facility, even if steam conditions of 650° C. or higher are adopted. In a steam turbine facility including a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine, the intermediate-pressure turbine is separated into a first intermediate-pressure turbine on a high-temperature and high-pressure side and a second intermediate-pressure turbine on a low-temperature and low-temperature side, at least any one of the rotors and casings of the steam-introduction-side turbines into which steam with a temperature of 650° C. or higher is introduced is formed from Ni-based alloy, and at least any one of the overall rotors and the overall casings of the turbines are constructed by joining together a plurality of rotor members or casing members by welding.

Abstract: The object of the invention is to provide a low-pressure turbine rotor capable of maintaining mechanical strength characteristics, and without problems in terms of quality without increasing manufacturing costs and manufacturing days, even if high temperature steam is introduced into the low-pressure turbine. A low-pressure turbine rotor used in a steam turbine facility including a high-pressure turbine, an intermediate-pressure turbine, and a low-pressure turbine includes a member formed from 1CrMoV steel, 2.25CrMoV steel, or 10CrMoV steel arranged on a steam inlet side, and a member formed from 3.5Ni steel arranged on a steam outlet side, which are joined together by welding. Alternatively, the member arranged on the steam inlet side and the member arranged on the steam outlet side, both of which are formed from 3.5Ni steel, are joined together by welding, and the member arranged on the steam inlet side is made of low-impurity 3.5Ni steel containing, by weight %, Si: 0.1% or less, Mn: 0.

Abstract: A seal structure that achieves a thick abradable film, thereby improving sealing performance, is provided. A seal structure is provided with at least one fin that projects in a ring-shape from a circumferential surface of a rotating shaft and that is provided along an axial direction and a seal member having a ring-shaped sealing surface opposed to the fin, and on which an abradable layer is formed by thermally spraying abradable material onto the sealing surface, the seal structure is provided with tapered portions inclined in a radial direction at end portions of the sealing surface in the axial direction.

Abstract: A leaf seal as a shaft seal mechanism is made compact and enables reduction of manufacturing cost. Plural thin plates 29 lapped one on another in layers have their outer circumferential proximal ends fixed to each other by welding so that an annular thin plate assembly 29A having flexibility is formed. This thin plate assembly 29A is bent and assembled to form the leaf seal 25.

Abstract: The present invention relates to a low thermal expansion Ni-base superalloy containing, in terms of mass %, C: 0.15% or less; Si: 1% or less; Mn: 1% or less; Cr: 5% or more but less than 20%; at least one of Mo, W and Re, in which Mo+½(W+Re) is 5% or more but less than 20%; W: 10% or less; Al: 0.1 to 2.5%; Ti: 0.10 to 0.95%; Nb+½Ta: 1.5% or less; B: 0.001 to 0.02%; Zr: 0.001 to 0.2%; Fe: 4.0% or less; and a balance of inevitable impurities and Ni, in which the total amount of Al, Ti, Nb and Ta is 2.0 to 6.5% in terms of atomic %. The low thermal expansion Ni-base superalloy of the present invention has a thermal expansion coefficient almost equal to that of 12 Cr ferritic steel, excellent high temperature strength, excellent corrosion and oxidation resistance, good hot-workability, and excellent weldability.

Abstract: A shaft sealing mechanism of an annular shape having at least one divided portion, which is installed in an annular space between a rotor and a stator, includes a group of thin plates. Outer peripheral ends of the thin plates are joined, and inner peripheral free ends come in contact with the rotor in a sliding manner so that a surface of the rotor and the thin plates form an acute angle to partition the annular space into a high-pressure region and a low-pressure region without being joined. At least a low-pressure gap near the divided portion is set to be larger than a low-pressure gap in a circumferential direction other than near the divided portion.

Abstract: A shaft seal mechanism (leaf seal) by which a desired seal performance can be stably obtained is provided. The shaft seal mechanism comprises a concave groove 71 formed larger than a minimum size of a plate width of thin plates 29 and a fitting piece 61 fitted in a gap between the concave groove 71 and a leaf seal 25. The leaf seal 25 comprises an annular thin plate assembly 29A constructed by the thin plates 29 and a plate spring 56 integrally formed therewith supporting the annular thin plate assembly 29A to be levitated coaxially with a rotating shaft 23. The thin plates 29 have their outer circumferential proximal end side made movable relative to the concave groove 71. A shaft seal mechanism assembling structure is also provided comprising a pressure receiving surface 61b and a lower pressure side plate 54 forming a predetermined gap size between the pressure receiving surface 61b and one side edges of the thin plates 29.

Abstract: There is provided a shaft sealing mechanism in which, even in a case where eccentricity occurs in a parent machine, flutter behavior of the sheets can be reliably prevented, the sheets can be prevented from failing due to fatigue, and also a long life and reliability of the shaft sealing mechanism can be improved. In a shaft sealing mechanism which prevents fluid from flowing in an axial direction of a rotor through an annular gap between the rotor and a stator, there are provided a high pressure side plate positioned on a high pressure side region of a plurality of sheets, and a low pressure side plate positioned on a low pressure side region of a plurality of sheets, and the construction is such that in a state in which the plurality of sheets is fixed on the stator side, and when under gas pressure, the parts make contact with each other.

Abstract: A shaft sealing mechanism of an annular shape having at least one divided portion, which is installed in an annular space between a rotor and a stator, includes a group of thin plates. Outer peripheral ends of the thin plates are joined, and inner peripheral free ends come in contact with the rotor in a sliding manner so that a surface of the rotor and the thin plates form an acute angle to partition the annular space into a high-pressure region and a low-pressure region without being joined. At least a low-pressure gap near the divided portion is set to be larger than a low-pressure gap in a circumferential direction other than near the divided portion.

Abstract: The shaft seal structure is based on a leaf seal that includes springs, disposed between the stator blades and the leaf seal ring, to force the leaf seal ring away from the rotation shaft, and pressure guiding grooves for guiding the fluid pressure, through a boundary of planar plates, to a space between the outer peripheral surface of the leaf seal ring and the inner peripheral surface of the stator blade. Also, a turbine may be provided with the leaf seal so as to reduce gas leakage from the high-pressure-region to the low-pressure-region as well as to control the frictional wear between the planar plates and the rotation shaft.

Abstract: The present invention provides a method for producing a low thermal expansion Ni-base superalloy, which includes: preparing an alloy including, by weight %, C: 0.15% or less, Si: 1% or less, Mn: 1% or less, Cr: 5 to 20%, at least one of Mo, W and Re, which satisfy the relationship Mo+½(W+Re): 17 to 27%, Al: 0.1 to 2%, Ti: 0.1 to 2%, Nb and Ta, which satisfy the relationship Nb+Ta/2: 1.5% or less, Fe: 10% or less, Co: 5% or less, B: 0.001 to 0.02%, Zr: 0.001 to 0.2%, a reminder of Ni and inevitable components; subjecting the alloy to a solution heat treatment under the condition of at a temperature of 1000 to 1200° C.; subjecting the alloy to either a carbide stabilizing treatment for making aggregated carbides on grain boundaries and stabilizing the carbides under the conditions of at a temperature of not less than 850° C. and less than 1000° C.

Abstract: A shaft seal mechanism (leaf seal) by which a desired seal performance can be stably obtained is provided. The shaft seal mechanism comprises a concave groove 71 formed larger than a minimum size of a plate width of thin plates 29 aid a fitting piece 61 fitted in a gap between the concave groove 71 and a leaf seal 25. The leaf seal 25 comprises an annular thin plate assembly 29A constructed by the thin plates 29 and a plate spring 56 integrally formed therewith supporting the annular thin plate assembly 29A to be levitated coaxially with a rotating shaft 23. The thin plates 29 have their outer circumferential proximal end side made movable relative to the concave groove 71. A shaft seal mechanism assembling structure is also provided comprising a pressure receiving surface 61b and a lower pressure side plate 54 forming a predetermined gap size between the pressure receiving surface 61b and one side edges of the thin plates 29.

Abstract: A leaf seal as a shaft seal mechanism is made compact and enables reduction of manufacturing cost. Plural thin plates 29 lapped one on another in layers have their outer circumferential proximal ends fixed to each other by welding so that an annular thin plate assembly 29A having a flexibility is formed. This thin plate assembly 29A is bent and assembled to form the leaf seal 25.