Turbine blade and gas turbine
AssigneeMitsubishi Heavy Industries, Ltd.
InventorsKoichiro Iida, Ryuta Ito
Life of this patent
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Abstract
A turbine blade includes a blade body including a top plate at a tip portion which is outside of a turbine rotor in a radial direction of the turbine blade and has an outer surface configured to face an inner circumferential surface of a casing, and a tip thinning which protrudes radially outward in the radial direction of the turbine blade from the outer surface of the top plate and extends from a leading edge side of the blade body to a trailing edge side of the blade body. A protrusion amount of the tip thinning based on the outer surface of the top plate is 0.25 times or more and 2.00 times or less a diameter of a discharge port of a cooling hole which passes through the top plate.
Claims18
A turbine blade, comprising:
- a blade body including a pressure-surface-side blade wall and a suction-surface-side blade wall extending in a radial direction of the turbine blade and being connected to each other at a leading edge of the blade body and a trailing edge of the blade body, and a top plate having an outer surface configured to face an inner circumferential surface of a casing, the top plate being provided at a tip portion, among end portions of the pressure-surface-side blade wall and the suction-surface-side blade wall;
- and
- a tip-thinning portion protruding outward in the radial direction of the turbine blade from the outer surface of the top plate, the tip-thinning portion extending from a leading edge side of the blade body to a trailing edge side of the blade body, and the tip-thinning portion being closer to a pressure-surface-side blade wall side of the top plate than a suction-surface-side blade wall side of the top plate,
- wherein:
- the blade body includes:
- (i) a cooling hole defined to pass through the top plate, (ii) an introduction port defined at a position of an inner surface of the top plate and configured to introduce a cooling medium into the cooling hole, and (iii) a discharge port defined in the outer surface of the top plate closer to the pressure-surface-side blade wall side of the top plate than the tip-thinning portion and configured to discharge the cooling medium via the cooling hole;
- a protrusion amount of the tip-thinning portion, based on the outer surface of the top plate, is within a range of at least 0.25 times to at most 2.00 times a diameter of the discharge port of the cooling hole;
- the outer surface of the top plate extends in a planar shape from the tip-thinning portion toward the suction-surface-side blade wall side of the top plate, and is configured to direct the cooling medium which has passed through the tip-thinning portion along the outer surface of the top plate toward the suction-surface-side blade wall side of the top plate;
- and
- the tip-thinning portion is the only tip-thinning portion protruding outward in the radial direction of the turbine blade from the top plate.
Dependencies are inferred from the claim text.