Seal member, turbine, and gas turbine

1. A seal member capable of being installed at a vane row constituted of a plurality of vanes disposed side by side in a circumferential direction of an axis of a turbine,

wherein,

the plurality of vanes comprises:

a vane main body extending in a radial direction of the axis;

an outer shroud installed at an outer end section of the vane main body in the radial direction of the axis;

an inner shroud installed at an inner end section of the vane main body in the radial direction of the axis to form a main flow path of a combustion gas between the outer shroud and the inner shroud; and

a retainer protruding inward in the radial direction of the axis from an inner surface of the inner shroud in the radial direction of the axis,

a space which stores air in a pressurized state, for generating the combustion gas, formed in the radial direction of the axis of the inner shroud and upstream of the retainer in a direction along the axis in a direction of the combustion gas in the turbine,

the inner shrouds in the vanes which are adjacent to each other in the circumferential direction of the axis are adjacent to each other in the circumferential direction of the axis via a first gap,

the vane main bodies in the vanes which are adjacent to each other in the circumferential direction of the axis are adjacent to each other in the circumferential direction of the axis via a second gap,

the retainers of the vanes which are adjacent to each other in the circumferential direction of the axis are adjacent to each other in the circumferential direction of the axis via a third gap,

the seal member bridges between the retainers and closes the third gap, a first end of the seal member being positioned upstream in a direction along the axis in a direction of the combustion gas in the turbine and a second end of the seal member is positioned downstream in the direction along the axis in the direction of the combustion gas in the turbine,

further comprises:

a longitudinal seal plate that forms a plate shape extending from an end section inside of the retainer in the radial direction of the axis to a halfway position outside in the radial direction of the axis;

a diagonal seal plate having one end in contact with an end section outside of the longitudinal seal plate in the radial direction of the axis and forming a plate shape inclined and extending from the inside toward the outside in the radial direction of the axis as it moves downstream, and

the diagonal seal plate extends from a downstream surface of the end section outside of the longitudinal seal plate toward the downstream in the direction along the axis so that the diagonal seal plate gradually goes apart from the end section outside of the longitudinal seal plate.

2. The seal member according to claim 1 , wherein the first end is positioned upstream in the direction along the axis in the flow direction of the combustion gas from a same pressure position, which is a position in the main flow path at which the pressure is the same as the pressure on the downstream side of the retainer and on the inside of the inner shroud in the radial direction of the axis, and the same pressure position is a position so that the pressure on the downstream side of the same pressure position is lower than the pressure on the upstream side of the same pressure position, and

the second end is positioned downstream from the same pressure position.

3. A turbine comprising the seal member according to claim 1 or 2 .

4. A gas turbine comprising the turbine according to claim 3 .

5. The seal member according to claim 1 , wherein

along the second gap, the first end of the seal member is positioned upstream in the direction along the axis in the flow direction of the combustion gas from an intersection point between the first gap and a throat line connecting contact points of minimum inscribed circle in contact with the vane main bodies adjacent to each other,

the second end of the seal member is positioned downstream from the intersection point.