Abstract: Precision cast hollow stationary blade used for final stage of steam turbine is improved to enhance drain recovery efficiency. Hollows (4, 5), sectioned by rib (6) to be independent of each other, are formed in stationary blade (1) passing therethrough from outer shroud 2 to inner shroud 3. A plurality of ventral slits (10 to 20) are provided on blade surface ventral side linearly with predetermined interval between the slits in two parallel rows. Dorsal slits (21 to 26) are also provided linearly with predetermined interval between the slits. Drain on blade surface enters the hollows (5, 4) through the ventral slits (10 to 20) and the dorsal slits (21 to 26), respectively, and flows out of the outer shroud (2) or the inner shroud (3) as drain (40 to 43) to be recovered.

Abstract: A two stage jointed stationary blade of a high pressure or intermediate pressure steam turbine is formed with a bolt joint in place of a welded joint so as to make detachment and disassembly possible, and thereby facilitating maintenance and inspection work and reducing assembling man-hours. A stationary blade (front stage)(2), outer ring front portion (1) and inner ring front portion (3) are welded into an integral structure. A stationary blade (rear stage) 22, outer ring rear portion (21) and inner ring rear portion (23) are also welded into an integral structure. The outer ring front portion 1, outer ring center portion 10 and the outer ring rear portion 21 are mutually engaged via engaging portions (4, 11 and 12, 24) with precise positioning and then jointed together integrally by bolt (30).

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

Abstract: A cooling architecture for flanges of a steam turbine casing, which effectively cools the flanges coupled by bolts to prevent the leakage of the steam caused by a decrease of the fastening force of the bolts. An upper casing 10 and a lower casing 11 are joined together at flanges 12 and 13 which are fastened and secured by bolts to hermetically seal a steam turbine. Pipes 20 are secured so as to be contacted to the peripheral of the flanges 12 and 13, and a side heat insulator 15a is fitted thereto from the outer side. Each pipe 20 is arranged corresponding to each bolt, or a plurality of pipes are arranged corresponding to each bolt 14. The flanges 12 and 13 are heated by the internal high-temperature steam, the ambient air 30 is introduced into the pipe 20 from the lower end thereof due to the natural convection thereby to cool the flanges 12, 13 and the bolts 14. Accordingly, a decrease of the fastening force of the bolts, and steam leakage, hardly occur.

Abstract: A structure for preventing deformation of a gland portion of a low pressure steam turbine by preventing wet steam from entering the gland portion. The gland portion includes a gland casing (3) that surrounds a gland portion periphery (2) of a rotor (1). A portion of steam (20), in the form of wet steam (21a), flows into a cavity (10) through a gap (11). Accordingly, a ridge (15) is provided on and around the entire periphery of the rotor (1), and thereby the wet steam (21a) is caused to flow in a swirling manner, and is prevented from flowing toward the gland portion periphery (2). Also, water in the wet steam (21a) scatters therearound so that the gland casing (3) and the seal portion (4, 5) are prevented from being partially cooled. Thus, contact with the rotor (1) is avoided and vibration caused thereby is prevented.

Abstract: The present invention relates to a flexible inlet tube for a high and intermediate pressure steam turbine. A reheat steam inlet tube is constructed integrally with a casing. The inlet tube has a double tube portion to form an annular groove. The lower end of the double tube portion has an expanded diameter, and a vertical sliding motion can be accomplished between the expanded diameter portion and a flange fixed to a thermal shield, so that thermal elongation is absorbed. Low-temperature steam flows into the annular groove from an in-casing space through a hole, circulates in the annular groove, and flows out to a steam passage in an intermediate pressure turbine section, by which the interior of the annular groove is cooled, so that a temperature rise of the casing can be prevented.

Abstract: The present invention relates to a leak reducing structure in a steam turbine having high pressure, intermediate pressure, and low pressure turbine sections in a single casing, in which steam leaking from the high pressure side to the intermediate pressure side is recovered to be used effectively. The high pressure, intermediate pressure, and low pressure turbine sections are arranged along a rotor in an external casing. High-pressure steam from a high-pressure steam inlet port passes through a nozzle chamber formed integrally with a dummy ring, and flows into the high pressure turbine section to do work. On the other hand, some of high-pressure steam attempts to leak from a seal portion of the dummy ring to the intermediate pressure turbine section side. However, the leaking steam flows from point X of an external pipe to point Y on the high pressure side to be recovered.

Abstract: There is provided a device for aiding transportation of a steam turbine which includes a rotor extending along a longitudinal axis and having multistage stationary and moving blades, a casing, supported by a base structure, for enclosing the rotor, bearings for rotationally supporting the rotor, and a pair of glands for sealing between the casing and the rotor, the casing including longitudinally opposite side flanges, the glands being mounted onto gland portions which are provided on the respective sides of the rotor outside of the casing and attached to the respective side flanges of the casing through a pair of flexible members, the device includes restrainers which are adapted to replace the glands after the glands are removed from the rotor and the casing.

Abstract: A steam turbine different material welded rotor, constructed by rotors of different materials being jointed together by welding has the strength of a jointed portion increased and inspection of the jointed portion facilitated. A bearing portion rotor 1 and high temperature portion rotor 2 are jointed at weld portion A, the high temperature portion rotor 2 and low temperature portion rotor 3 at weld portion B and the low temperature portion rotor 3 and bearing portion rotor 4 at weld portion C. Cavity portions 5, 6 are formed in the weld portions B, C, respectively. Inspection holes 7, 8 are also provided in the weld portions B, C. The high temperature portion rotor 2 is made of high heat resistant 12Cr steel and other rotors are made of low alloy steel, wherein the rotor 1 is of 2.multidot.1/4 CrMoV steel and the rotors 3, 4 are of 3.multidot.1/2 NiCrMoV steel.

Abstract: A material for a gas turbine disk comprises 0.05 to 0.15 wt % of carbon, 0.10 wt % or less of silicon, 0.40 wt % or less of manganese, 9.0 to 12.0 wt % of chromium, 1.0 to 3.5 wt % of nickel, 0.50 to 0.90 wt % of molybdenum, 1.0 to 2.0 wt % of tungsten, 0.10 to 0.30 wt % of vanadium, 0.01 to 0.10 wt % of niobium, 0.01 to 0.05 wt % of nitrogen, and a remainder comprising iron and unavoidable impurities, wherein the contents of nickel, molybdenum and tungsten satisfy a relationship -1.5 wt %.ltoreq.Mo+W/2-Ni.ltoreq.0.7 wt %. Accordingly, unlike conventional gas turbine disk materials such as a heat resisting steel of 12Cr-type which can be used in an operation at about 400.degree. C., but has reduced toughness and high-temperature creep characteristics in an operation at about 500.degree. C., this material is allowed to have a satisfactory toughness and excellent high-temperature creep characteristics and can be suitably used at high temperatures.