Patent ID: 11891920
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A turbine stator vane, comprising:
a vane body which includes:
an airfoil portion which has a serpentine flow passage inside thereof, the serpentine flow passage including a plurality of cooling flow passages and a plurality of turn-back flow passages, at least one of the turn-back flow passages being disposed at an outer side or an inner side, in a vane height direction, of a gas path surface which defines a combustion gas flow passage; and
a shroud disposed on at least one of a tip end side or a root end side, in the vane height direction, of the airfoil portion; and

a lid portion fixed to an end portion at the tip end side or the root end side, in the vane height direction, of the airfoil portion, the lid portion forming the at least one turn-back flow passage and being provided as a separate member from the airfoil portion,
wherein the shroud includes:
a bottom portion forming, in the vane height direction, an inner surface opposite to the gas path surface in the vane height direction;
an outer wall portion formed on opposite ends, in an axial direction and the circumferential direction, of the bottom portion, the outer wall portion extending in the vane height direction; and
an impingement plate disposed in an internal space surrounded by the outer wall portion and the bottom portion, the impingement plate having a plurality of through holes,

wherein the impingement plate includes:
a second impingement plate close to the inner surface in the vane height direction; and
a first impingement plate positioned in a direction separating from the inner surface, in the vane height direction, with respect to the second impingement plate,

wherein at least one step portion extending in the axial direction or the circumferential direction is disposed between the outer wall portion and the lid portion, the step portion connecting the first impingement plate and the second impingement plate and being bent in the vane height direction,
wherein a hole diameter of first through holes being the through holes formed on the first impingement plate is greater than a hole diameter of second through holes being the through holes formed on the second impingement plate,
wherein an arrangement pitch of the first through holes formed on the first impingement plate is greater than the arrangement pitch of the second through holes formed on the second impingement plate, and
wherein the second impingement plate comprises two second impingement plates fixed to an inner surface of the outer wall portion of the shroud and to an outer wall surface of the lid portion respectively, and the first impingement plate is positioned between the two second impingement plates via the step portion.