Abstract: A method for producing a low thermal expansion Ni-base superalloy including the steps of subjecting the alloy to a solution heat treatment under the condition of at a temperature of 1000 to 1200° C. and 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. and for 1 to 50 hours, or a carbide stabilizing treatment for making aggregated carbides on grain boundaries and stabilizing the carbides by cooling from the temperature in the solution heat treatment to 850° C. at a cooling rate of 100° C. or less per hour. The method also including the steps of subjecting the alloy to a first aging treatment for precipitating y? phase under the conditions of at a temperature of 720 to 900° C.

Abstract: It is the objective of the present invention to enable smooth rotation of the grid plate and normal operation of the bypass valve, regardless of the operational state of the gas turbine.

Abstract: A low thermal expansion Ni-base superalloy contains, by weight % (hereinafter the same as long as not particularly defined) 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 of Mo+½(W+Re) of 17 (exclusive) to 25%; Al: 0.2 to 2%; Ti: 0.5 to 4.5%; Fe of 10% or less; at least one of B: 0.02% and Zr: 0.2% or less; a remainder of Ni and inevitable impurities; wherein the atomic % of Al+Ti is 2.5 to 7.0.

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: The division wall is made up of a plurality of division wall sections forming a passage wall of high temperature gas which are connected in the direction of arrangement of blades to form a wall surface having a roughly circular cross section as a whole, a gas flow restricting structure for preventing high temperature gas from passing through a gap formed at a connecting portion between the division wall sections in the flow direction of the high temperature gas from the opening on the upstream side of the high temperature gas in the gap, or a gas flow restricting structure for preventing the high temperature gas from being embraced in the gap, for example, a sealing member formed into a prism having a T-shape cross section as a whole composed of a plane portion as a sealing portion and a projected portion for filling the gap is provided.

Abstract: In a gas turbine, blade ring cooling passages are provided inside a first blade ring and a second blade ring. The blade ring cooling passages are connected with each other through a communication pipe that is arranged in an axial direction of the blade ring. From outside of a wheel chamber, cooling air to cool down stationary blades is sent with pressure into an inside of the stationary blades that are installed on an inner wall of the blade rings. Thermal shields are provided on outer surfaces of the blade rings and communication pipes through gaps therebetween. In the gaps between the outer surfaces of the blade rings or the outer surfaces of the communication pipes and the thermal shields, partitions are installed to stagnate the cooling air to cool down the stationary blades.

Abstract: It is the objective of the present invention to enable smooth rotation of the grid plate and normal operation of the bypass valve, regardless of the operational state of the gas turbine.

Abstract: A gas turbine blade ring is cooled by steam whose temperature, pressure and flow rate are controlled so that a clearance between a moving blade tip and blade ring is maintained appropriately. Steam from a steam turbine bottoming cycle (10) flows into a blade ring cooling passage (8) of a gas turbine (1) via piping (12) for cooling the blade ring. The steam, having cooled the blade ring, is supplied into a transition piece cooling passage (9) of a combustor (3) for cooling the transition piece, and is then recovered into the steam turbine bottoming cycle (10) via piping (14). While the steam cools the blade ring, the temperature, pressure and flow rate of the steam are controlled so that thermal elongation of the blade ring is adjusted and the clearance at the moving blade tip is controlled so as to approach a target value. Thus, the clearance is maintained as small as possible in operation and the gas turbine performance is enhanced.

Abstract: Blade ring cooling passages (14, 15) are provided inside a first blade ring (8) and a second blade ring (9). The blade ring cooling passages (14, 15) are connected with each other through a communication pipe (16) that is arranged in an axial direction of the blade ring. From outside of a wheel chamber (1), cooling air (17) to cool down stationary blades is sent with pressure into inside of the stationary blades which are installed inner wall of the blade rings. Thermal shields (18) are provided on outer surfaces of the blade rings (14, 15) and communication pipes (16) through gaps therebetween. In the gaps between the outer surfaces of the blade rings (8, 9) or the outer surfaces of the communication pipes (16) and the thermal shields (18), partitions are installed to stagnate the cooling air (17) to cool down the stationary blades.

Abstract: A low thermal expansion Ni-base superalloy contains, by weight % (hereinafter the same as long as not particularly defined) 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 of Mo+½ (W+Re) of 17 (exclusive) to 25%; Al: 0.2 to 2%; Ti: 0.5 to 4.5%; Fe of 10% or less; at least one of B: 0.02% and Zr: 0.2% or less; a remainder of Ni and inevitable impurities; wherein the atomic % of Al+Ti is 2.5 to 7.0.

Abstract: In the gas turbine split ring, on an outer peripheral surface 1b between two cabin attachment flanges, a circumferential rib which extends in the circumferential direction and an axial rib which extends in the axial direction and has a height taller than that of the circumferential rib are, respectively, formed in plural lines, so that it is possible to suppress heat deformation in the axial direction which largely contributes to reduction of the tip clearance compared to head deformation in the circumferential direction more efficiently.

Abstract: A seal ring provided between a rotating portion and a fixed portion in a rotating machine of steam turbine and the like is improved to accurately carry out predetermined movement so as to not cause deterioration of sealing performance. The seal ring is split into upper, lower, right side and left side seal ring pieces slidably contacting with each other via split planes with spaces being formed in the respective split planes. Springs are interposed in the spaces for activation in upward and downward directions. The upper and lower seal ring pieces are engaged with seal ring guides and the right side and left side seal ring pieces are engaged with seal ring guides so that all of the seal ring pieces are slidable in the upward and downward directions. Further, on the respective tips of the seal ring guides spaces of the upper seal ring piece and spaces of the lower seal ring piece are formed and springs are provided in the spaces for activation in the upward and downward directions.

Abstract: A cooling structure of a combustor tail tube is capable of avoiding the formation of cracks in the tail tube by lessening thermal stress and preventing thermal deformation, thus extending the service life. A multiplicity of cooling jackets (5) extend in the longitudinal direction of the tail tube of a gas turbine combustor along the entire circumference of the tail tube wall. The passage sectional area of the cooling jackets (5) is varied depending on the metal temperature of parts of the tail tube (4). For example, the passage sectional area of the cooling jackets (5) formed at the rotor side wall and the mutually opposite side walls of the adjacent tail tube is larger than the passage sectional area of the cooling jackets (5) formed at the casing side wall.

Abstract: Gas turbine rotor blade tip loss is reduced and loss caused by leakage of working fluid through gap between members constituting an annular flow passage is reduced. Turbine (AT) of a gas turbine (GT) constituting a combined cycle plant (CC) is supported to a turbine casing (4) to be expandable or contractible in turbine shaft (32) radial direction. First blade ring (41) corresponds to first stage turbine stator blades (TS1) and rotor blades (TR1) and comprises a first heating medium flow passage (41P) for steam circulation therein. Second blade ring (42) corresponds to second stage turbine stator blades (TS2) and rotor blades (TR2) and comprises a second heating medium flow passage (42P) for steam circulation therein. Further provided is a communication member (45) for connecting the first blade ring (41) and second blade ring (42) to each other and for communicating the first heating medium flow passage (41P) and second heating medium flow passage (42P) with each other.

Abstract: In the gas turbine split ring, on an outer peripheral surface 1b between two cabin attachment flanges, a circumferential rib which extends in the circumferential direction and an axial rib which extends in the axial direction and has a height taller than that of the circumferential rib are, respectively, formed in plural lines, so that it is possible to suppress heat deformation in the axial direction which largely contributes to reduction of the tip clearance compared to head deformation in the circumferential direction more efficiently.

Abstract: The division wall is made up of a plurality of division wall sections forming a passage wall of high temperature gas which are connected in the direction of arrangement of blades to form a wall surface having a roughly circular cross section as a whole, a gas flow restricting structure for preventing high temperature gas from passing through a gap formed at a connecting portion between the division wall sections in the flow direction of the high temperature gas from the opening on the upstream side of the high temperature gas in the gap, or a gas flow restricting structure for preventing the high temperature gas from being embraced in the gap, for example, a sealing member formed into a prism having a T-shape cross section as a whole composed of a plane portion as a sealing portion and a projected portion for filling the gap is provided.

Abstract: A low thermal expansion Ni-base superalloy contains, by weight % (hereinafter the same as long as not particularly defined), 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 of Mo+½ (W+Re) of 10 to 25%; Al: 0.2 to 2%; Ti: 0.5 to 4.5%; Fe of 10% or less; at least one of B: 0.02% and Zr: 0.2% or less; a remainder of Ni and inevitable impurities; wherein the atomic % of Al+Ti is 2.5 to 7.0.

Abstract: A steam turbine includes a rotor which extends along a longitudinal axis and having at least two different pressure turbine portions disposed around and along the rotor. Each of the turbine portions has multiple stages. A casing encloses the rotor and has at least one steam inlet. A dummy ring is provided stationarily around the rotor to separate and seal between the two different pressure turbine portions. The dummy ring defines nozzle chamber for receiving the steam from the steam inlet port and a plurality of nozzles for directing the steam from the nozzle chamber toward the higher pressure turbine portion. The dummy ring and the casing define a space therebetween. The space is fluidly connected to the higher pressure turbine portion. A steam passage extends between the space and a steam passage downstream of the last stage of the higher pressure turbine portion.

Abstract: A nozzle chamber warming-up structure comprises a ring mounted about a rotor of the turbine and defines an annular space surrounding the rotor. The annular spaced is divided by dividing walls into a plurality of steam chambers distributed circumferentially about the rotor, including first ad second upper steam chambers and at least one lower steam chamber. The dividing wall have holes such that steam supplied into the first upper steam chamber flows through the hole in one of the dividing walls into the one or more lower steam chambers, and then flows through The hole in another of the dividing walls into the second upper steam chamber. The steam that flows circumferentially around the ring and warms up the nozzle chamber uniformly.

Abstract: To present a cooling structure of combustor tail tube capable of avoiding formation of cracks in the tail tube by lessening thermal stress and preventing thermal deformation, and extending the service life, the invention provides a cooling structure of combustor tail tube forming a multiplicity of cooling jackets (5) extending in the longitudinal direction of tail tube of a gas turbine combustor along the entire circumference of the tail tube wall, in which passage sectional area of the cooling jackets (5) is varied depending on the metal temperature of parts of the tail tube (4), for example, the passage sectional area of the cooling jackets (5) formed at the rotor side wall and the mutually opposite side walls of the adjacent tail tube is formed larger than the passage sectional area of the cooling jackets (5) formed at the casing side wall.