Abstract: In the blade structure in a gas turbine, front-edge including angles are made large. As a result, a curve of a relative relationship between incidence angles ic1 and is1 and pressure loss becomes mild. Entrance metal angles are made small. As a result, it becomes possible to make the incidence angles small. Chord length of a tip portion of a moving blade is made large. As a result, it becomes possible to make small the deceleration on a rear surface of the tip portion of the moving blade. Accordingly, it becomes possible to make the pressure loss small, and therefore, it becomes possible to improve the turbine efficiency.

Abstract: The blade has such a shape that the diameters of circles inscribing the belly and back sides at different positions of adjacent blades decreases as one goes from the front edge to the rear edge. Since the blade has such a shape, even if the influent angle and effluent angle of gases are increased, a deceleration passage is not formed in the passage between the adjacent moving blades.

Abstract: The pressure ratio &Dgr;P4S of a final stage moving blade is reduced. As a result, the Mach number in the final stage moving blade can be suppressed, and in the gas turbine operating at a pressure ratio of 20 or more, therefore, decline of turbine efficiency due to shock wave loss can be prevented securely.

Abstract: A gas turbine comprises a shroud integral type moving blade and a split ring. The moving blade includes a shroud provided from a leading edge of a tip of a moving blade to a trailing edge and whose outer side surface is provided with a seal fin. A radius of a tip end of the seal fin is substantially equal to a radius of a shroud trailing edge end. The split ring has a structure in which a radius of its inner peripheral surface is slightly larger than a radius of the seal fin tip end and the radius of the shroud trailing edge end.

Abstract: There is provided an axial-flow turbine comprising an exhaust chamber; a turbine including multiple stage rotor blades, said multiple stage rotor blade including terminal stage rotor blades; an annular diffuser located between the turbine and the exhaust chamber; and an annular axial-flow turbine passage defined by the turbine, the diffuser and the exhaust chamber, wherein fluid flows through the axial-flow turbine passage toward the exhaust chamber, and an annular stepped portion which inwardly projects in a radial direction is formed on the portion of an inner wall of the axial-flow turbine passage that is located on the downstream side of a trailing edge of a tip portion of the terminal stage rotor blades provided in the flow direction of the fluid. In the stepped portion, a projecting portion which inwardly projects in a radial direction may be provided.

Abstract: A gas turbine cooled stationary blade has a blade structure and outer and inner shrouds enhancing cooling efficiency and preventing the occurrence of cracks due to thermal stresses. A blade (1) wall thickness, between 75% and 100% of the blade height of a blade leading edge portion, is made thicker, and the blade (1) wall thickness of other portions is made thinner, as compared with a conventional case. Protruding ribs (4) are provided on a blade (1) convex side inner wall between 0% and 100% of the blade height. A blade (1) trailing edge opening portion is made thinner than the conventional case. Outer shroud (2) is provided with cooling passages (5a, 5b) for air flow in both side end portions. Inner shroud (3) is provided with cooling passages (9a, 9b) for air flow and cooling holes (13a, 13b) for air blow in the side end portions.

Abstract: A gas turbine comprises a shroud integral type moving blade and a split ring. The moving blade includes a shroud provided from a leading edge of a tip of a moving blade to a trailing edge and whose outer side surface is provided with a seal fin. A radius of a tip end of the seal fin is substantially equal to a radius of a shroud trailing edge end. The split ring has a structure in which a radius of its inner peripheral surface is slightly larger than a radius of the seal fin tip end and the radius of the shroud trailing edge end.

Abstract: There is provided an axial-flow turbine comprising an exhaust chamber; a turbine including multiple stage rotor blades, said multiple stage rotor blade including terminal stage rotor blades; an annular diffuser located between the turbine and the exhaust chamber; and an annular axial-flow turbine passage defined by the turbine, the diffuser and the exhaust chamber, wherein fluid flows through the axial-flow turbine passage toward the exhaust chamber, and an annular stepped portion which inwardly projects in a radial direction is formed on the portion of an inner wall of the axial-flow turbine passage that is located on the downstream side of a trailing edge of a tip portion of the terminal stage rotor blades provided in the flow direction of the fluid. In the stepped portion, a projecting portion which inwardly projects in a radial direction may be provided.

Abstract: The pressure ratio &Dgr;P4S of a final stage moving blade is reduced. As a result, the Mach number in the final stage moving blade can be suppressed, and in the gas turbine operating at a pressure ratio of 20 or more, therefore, decline of turbine efficiency due to shock wave loss can be prevented securely.

Abstract: The blade has such a shape that the diameters of circles inscribing the belly and back sides at different positions of adjacent blades decreases as one goes from the front edge to the rear edge. Since the blade has such a shape, even if the influent angle and effluent angle of gases are increased, a deceleration passage is not formed in the passage between the adjacent moving blades.

Abstract: In the blade structure in a gas turbine, front-edge including angles are made large. As a result, a curve of a relative relationship between incidence angles ic1 and is1 and pressure loss becomes mild. Entrance metal angles are made small. As a result, it becomes possible to make the incidence angles small. Chord length of a chip portion of a moving blade is made large. As a result, it becomes possible to make small the deceleration on a rear surface of the chip portion of the moving blade. Accordingly, it becomes possible to make the pressure loss small, and therefore, it becomes possible to improve the turbine efficiency.

Abstract: A shaft seal having a high abrasion resistance is disclosed, by which the leakage of the gas from the high-pressure side to the low-pressure side can be reduced. In the shaft seal, flexible leaves are multi-layered to form a ring shape. The shaft seal is mainly arranged around the rotation shaft of a gas turbine or the like. The relevant turbine comprises a casing, a compressor, a rotation shaft, moving blades attached to the rotation shaft, and stationary blades attached to the casing in a manner such that the stationary blades face the moving blades, wherein the shaft seals are provided between a plurality of stationary blades and the rotation shaft wherein the leaves of each shaft seal contact the rotation shaft. Under the rated operating conditions, the top ends of the leaves slightly separate from the surface of the rotation shaft due to the dynamic pressure generated by the rotation of the rotation shaft.

Abstract: A gas turbine stationary blade having passages (23, 24) that are provided in the stationary blade (10). A front cylindrical insert (2) is provided in the passage (23) and a rear cylindrical insert (5) is provided in the passage (24), and the inserts are supported at two supporting portions (3a, 3b), (6a, 6b), respectively. A projection (1) is provided at a leading edge portion of the blade so that the leading edge, where the thermal loads are high, is made smaller in size and the number of rows of cooling holes (11a) in the leading edge portion is reduced. Air blowing holes (4b) are provided on the dorsal side rear portion of the front insert (2) and film cooling holes (12) are provided on the dorsal side of the blade, both have diameters that are larger than other air blowing and cooling holes provided in the insert (2) and the blade (10), so that dust in the cooling air is caused to flow out, thereby preventing clogging of the holes.

Abstract: Gas turbine cooled stationary blade is improved in the structure of a blade and outer and inner shrouds to enhance cooling efficiency and to prevent occurrence of cracks due to thermal stresses. Blade (1) wall thickness between 75% and 100% of blade height of a blade leading edge portion is made thicker and blade (1) wall thickness of other portions is made thinner, as compared with a conventional case. Protruding ribs (4) are provided on a blade (1) convex side inner wall between 0% and 100% of the blade height. Blade (1) trailing edge opening portion is made thinner than the conventional case. Outer shroud (2) is provided with cooling passages (5a, 5b) for air flow in the shroud both side end portions. Inner shroud (3) is provided with cooling passages (9a, 9b) for air flow and cooling holes (13a, 13b) for air blow in the shroud both side end portions.

Abstract: A blade for a gas turbine includes an internally formed passage (a) for cooling the blade with steam. The ratio (t/c) of blade thickness (t) to chord length (c) should fall within the range of 0.10 to 0.15.

Abstract: A gas turbine seal structure provided between end portions of a moving blade platform and a stationary blade inside shroud. The sealing performance of the seal structure is improved by increasing the resistance to the flow of air. A seal plate (21, 31) is mounted to an end portion of a platform (2, 2′) of the moving blade (1) and a seal portion is formed by seal fins (22, 32) and a honeycomb seal (16, 17) disposed on a lower surface of an end portion (12a, 12b) of an inside shroud (12) of a stationary blade (11). Sealing air from the stationary blade (11) produces a high temperature in a cavity (14) and flows into a space (18, 19), and also air leaking from the cooling air of the moving blade (1) is able to escape into a high temperature combustion gas passage through a seal portion. However, since the seal plate has three seal fins (22, 32) that are inclined in a direction so as to oppose the air flow, air resistance is increased and the flow of air into the combustion gas passage is prevented.

Abstract: A tip shroud for a moving blade that is made thin and light for use at a gas turbine downstream stage. Cooling air holes (13 to 16) having a slot shape, are formed in a tip shroud (11) of the moving blade (10). The cooling holes are opened in two side faces of the tip shroud to release the cooling air from the inside of the moving blade (10). In the upper face of the tip shroud 11, there are formed cooling air holes 20, which communicate with the higher pressure side in a combustion gas flow direction R to release the cooling air so that the cooling air flows from the higher pressure side to the lower pressure side so as to cool a high stress portion Y. A high stress portion X is likewise cooled with the cooling air coming from an adjoining moving blade. The slot shapes of the cooling air holes (13 to 16) allow the cooling air to flow widely, thereby cooling the face of the tip shroud (11), and the cooling air holes 20 cool the high stress portions X and Y effectively.

Abstract: A seal plate at the platform portion of a gas turbine moving blade. The seal plate is inserted in a gap between the adjacent platforms at each end portion of a seal pin to prevent air from leaking to the outside. A groove is provided at each of four corners of the end portion of platform of the moving blade, and the seal plate is inserted to cover the gap so as to extend the end portions of the adjacent platforms, by which the gap between the platforms is blocked. A seal pin and end seal pins are inserted between the platforms to seal this portion. However, there is a gap at the end portions, so that cooling air leaks from the lower part of platform. Since the seal plate is inserted in the groove to block the gap, the sealing property is increased.

Abstract: The invention relates to a cavity constituted by a casing of a gas turbine and a moving blade with a tip shroud, by which a cavity space is made to a necessary minimum size, a main flow gas is prevented from being entrained and a pressure loss is reduced. A tip shroud (6) is mounted on a tip end portion of a moving blade (4), a fin (7) is mounted thereon, a recess-like cavity (15) narrower than the conventional one is formed by portions (12a) and (12b) of a casing (12) and the fin (7), and further a projecting portion (16) is provided to an upstream end portion of the tip shroud (6). The projecting portion (16) is at a position (13a) at a time of a cold start and is at a position (13b) at a time of a hot start run, even if a thermal expansion occurs, thus the projecting portion (16) is not in contact with the recess portion, a main flow gas (1) is less entrained within the cavity (15), and a pressure loss is reduced because of no swirl, so that a performance of the gas turbine is enhanced.

Abstract: A cooling passage in a turbine blade of gas turbine can be prevented from being blocked by a scale when the turbine blade is cooled by steam. A system for cooling a blade of a gas turbine having a compressor, a combustor and a turbine section comprises a cooling steam supply tube and a steam discharge tube providing communication with a cooling passage in a guide blade of the turbine section, and a cyclone separator provided in the middle of the steam supply tube in proximity to the guide blade.