Stator blade and gas turbine comprising same

A stator vane provided in a gas turbine, comprising:

• a blade body having a blade shape in a cross-section and extending in a blade-height direction having a direction component perpendicular to the cross section;
• a first insert and a second insert which have a tubular shape, extend in a tube-height direction, and are disposed inside the blade body so that the tube-height direction faces the blade-height direction;
• and
• an end cover,
• wherein the blade body includes a plurality of blade air passages extending in the blade-height direction inside the blade body,
• in the plurality of blade air passages, both a first blade air passage and a second blade air passage have an open end on a blade-height one side which is one side of a blade-height first side and a blade-height second side in the blade-height direction,
• both the first insert and the second insert include
• an outer peripheral plate portion having a tubular shape and extending in the tube-height direction, and
• a sealing plate portion that closes an end on a tube-height sealing side which is one side of the outer peripheral plate portion in the tube-height direction out of two sides in the tube-height direction,
• the outer peripheral plate portion has a plurality of impingement holes penetrating from an inside to an outside of the tubular outer peripheral plate portion,
• a tube-height opening side which is the other side of the outer peripheral plate portion in the tube-height direction is open,
• the outer peripheral plate portion of the first insert has a gap existing between the outer peripheral plate portion of the first insert and a first passage defining surface of the blade body defining the first blade air passage, and is disposed inside the first blade air passage so that cooling air flows into the outer peripheral plate portion from an opening of the first insert,
• the outer peripheral plate portion of the second insert is configured so that the tube-height opening side of the second insert faces the blade-height one side, has a gap existing between the outer peripheral plate portion of the second insert and a second passage defining surface of the blade body defining the second blade air passage, and is disposed inside the second blade air passage so that the cooling air flows from an opening of the second insert,
• the end cover is provided on the blade-height one side of the blade body so that the cooling air ejected from the plurality of impingement holes of the first insert to between the outer peripheral plate portion of the first insert and the first passage defining surface is guided into the second insert from the opening of the second insert through the opening of the first blade air passage, and covers the opening of the first blade air passage and the opening of the second insert,
• in the first blade air passage, an end on the blade-height first side and an end on the blade-height second side of the first blade air passage are open,
• in the second blade air passage, an end on the blade-height first side of the second blade air passage is closed, and an end on the blade-height second side is open,
• the first insert includes a flange portion spreading from an end on the tube-height opening side in the outer peripheral plate portion of the first insert toward an outer peripheral side of the outer peripheral plate portion of the first insert, extending to the first passage defining surface, and connected to the blade body,
• the second insert includes a flange portion spreading from an end on the tube-height opening side in the outer peripheral plate portion of the second insert toward an outer peripheral side of the outer peripheral plate portion of the second insert, extending to the second passage defining surface, and connected to the blade body,
• the outer peripheral plate portion of the first insert is disposed inside the first blade air passage so that the tube-height opening side of the first insert faces the blade-height first side, and
• the outer peripheral plate portion of the second insert is disposed inside the second blade air passage so that the tube-height opening side of the second insert faces the blade-height second side.