Vane and gas turbine including the same
A plurality of circumferential blowout passages that communicate with a cavity into which cooling air flows and that open in a circumferential end surface are formed in a shroud of a vane. Of a central region of the circumferential end surface, an upstream-side region of the circumferential end surface, and a downstream-side region of the circumferential end surface, at least the central region has openings of the plurality of circumferential blowout passages formed therein. A density that is the number of the openings of the circumferential blowout passages per unit length in an axial direction is highest in the central region.
1. A vane of a gas turbine in which a plurality of vanes are disposed in an array in a circumferential direction around a rotor shaft, the vane comprising:
a vane body that is disposed inside a combustion gas flow passage through which combustion gas flows, and that extends in a radial direction of the rotor shaft; and
a shroud that is formed at an end of the vane body in the radial direction and defines a part of the combustion gas flow passage, wherein
the shroud has a gas path surface that faces the radial direction and comes in contact with the combustion gas, a pair of circumferential end surfaces that face opposite sides in the circumferential direction, a cavity into which cooling air flows, and a plurality of circumferential blowout passages that communicate with the cavity and open in at least one of the pair of circumferential end surfaces,
each of the pair of circumferential end surfaces has a central region that is a region located inside a throat circle with a minimum radius while being in contact with both the vane body of the vane and a vane body of another vane adjacent to the vane in the circumferential direction, an upstream-side region that is located further on an upstream side of the combustion gas flow passage than the central region, and a downstream-side region that is located on an opposite side of the central region from the upstream side, and openings of the plurality of circumferential blowout passages are formed at least in the central region, and
a density that is the number of the openings of the circumferential blowout passages per unit length in an axial direction in which the rotor shaft extends is higher in the central region Than in the upstream-side region and the downstream-side region.
2. The vane of a gas turbine according to claim 1 , wherein the density of the openings of the circumferential blowout passages in the upstream-side region and the downstream-side region is zero.
3. The vane of a gas turbine according to claim 1 , wherein of the pair of circumferential end surfaces, one circumferential end surface forms a pressure-side end surface that is on a pressure side of the vane body in the circumferential direction, and the other circumferential end surface forms a suction-side end surface that is on a suction side of the vane body in the circumferential direction, and
the density of the openings of the plurality of circumferential blowout passages is higher in the pressure-side end surface than in the suction-side end surface.
4. The vane of a gas turbine according to claim 3 , wherein the density of the openings of the circumferential blowout passages in the suction-side end surface is zero.
5. The vane of a gas turbine according to claim 1 , wherein
each of the pair of circumferential end surfaces has a seal groove formed therein in which a seal plate that seals a gap between the shroud of the vane and the shroud of another vane adjacent to the vane in the circumferential direction is mounted, and
the openings of the plurality of circumferential blowout passages are formed on a side closer to the seal groove than to the gas path surface in the radial direction.
6. The vane of a gas turbine according to claim 1 , wherein
a circumferential end passage that communicates with the cavity and extends along each of the pair of circumferential end surfaces in a direction having a component of the axial direction is formed inside the shroud, and
relative to the circumferential end passage, the openings of the plurality of circumferential blowout passages are formed on an opposite side from the gas path surface in the radial direction.
7. The vane of a gas turbine according to claim 6 , wherein the plurality of circumferential blowout passages communicate with the circumferential end passage.
8. A gas turbine comprising:
the plurality of vanes according to claim 1 ;
the rotor shaft;
a plurality of blades mounted on the rotor shaft; and
a casing on an inner circumferential side of which the plurality of vanes are mounted and which covers the rotor shaft and the plurality of blades.