Turbine stator vane, turbine stator vane assembly, and steam turbine

A turbine stator vane assembly comprising:

• a turbine stator vane including a pressure surface extending in a radial direction intersecting with a flow direction of steam, and facing an upstream side in the flow direction, and a suction surface facing a downstream side in the flow direction;
• and
• an outer peripheral ring provided in an outer end portion of the turbine stator vane in the radial direction,
• wherein a plurality of grooves extending outward in the radial direction toward the downstream side are formed on at least the pressure surface,
• a ring groove connected to a groove of the plurality of grooves and extending toward the downstream side along an inner peripheral surface of the outer peripheral ring is formed on the inner peripheral surface of the outer peripheral ring, and
• an end portion on the downstream side of the plurality of grooves is connected to a slit that captures a liquefied component of the steam,
• wherein the turbine stator vane assembly further includes a fillet portion that connects the turbine stator vane and the inner peripheral surface, the fillet portion being curved in a direction away from a turbine stator vane side toward the inner peripheral surface of the outer peripheral ring side, and
• wherein the ring groove is formed on the inner peripheral surface side from the fillet portion.

A steam turbine comprising:

• a turbine stator vane extending in a radial direction intersecting with a flow direction of steam;
• an outer peripheral ring provided in an outer end portion of the turbine stator vane in the radial direction,
• a turbine rotor vane disposed with a gap on a downstream side of the turbine stator vane in the flow direction;
• and
• a turbine casing that covers the turbine stator vane and the turbine rotor vane from an outer peripheral side,
• wherein the turbine stator vane includes a pressure surface facing an upstream side in the flow direction, and a suction surface facing a downstream side in the flow direction,
• a plurality of grooves extending outward in the radial direction toward the downstream side are formed on at least the pressure surface,
• a hydrophilic uneven region having higher hydrophilicity than that of the pressure surface is formed around the grooves on the pressure surface, and
• an end portion on the downstream side of the plurality of grooves is connected to the gap, which serves as a slit that captures a liquefied component of the steam,
• a ring groove connected to a groove of the plurality of grooves and extending toward the downstream side along an inner peripheral surface of the outer peripheral ring is formed on the inner peripheral surface of the outer peripheral ring, and
• a fillet portion that connects the turbine stator vane and the inner peripheral surface, wherein the fillet portion is curved in a direction away from a turbine stator vane side toward the inner peripheral surface of the outer peripheral ring side, and the ring groove is formed on an inner peripheral surface side from the fillet portion.