Patent ID: 8777559

Claim:
A cooling system of ring segment that is formed from a plurality of segment bodies that are arranged in the circumferential direction to form a ring shape, and that cools a ring segment of a gas turbine that is arranged in a casing so that the inner peripheral surface is kept a fixed distance from the tips of turbine blades, comprising: a collision plate that has a plurality of small holes; a cooling space that is enclosed by the collision plate and a main body of the segment body; a first cavity that is arranged in the upstream end portion of the segment body in the flow direction of the combustion gas so as to be perpendicular to the axial direction of a rotating shaft; a first cooling passage that communicates from the cooling space to the first cavity; a second cooling passage that is provided in a position of the segment body other than a side end portion on the downstream and upstream of the segment body in the rotation direction of the rotating shaft, and communicates from the first cavity to a combustion gas space in the downstream end portion of the segment body in the flow direction of the combustion gas; and a third cooling passage that is arranged at a side end portion on the upstream of the segment body in the rotation direction of the rotating shaft, and that communicates from the cooling space to the combustion gas space in the side end portion, wherein the third cooling passage communicates with the first cavity via a second cavity.