Shroud assembly of gas turbine

#The present invention relates to a shroud assembly attached to a support to cover an inner peripheral surface of the support, the support being provided at a radially inner side of a casing of a gas turbine along a circumferential direction of the casing.

#A functional part or structure arranged at an outer peripheral portion of a moving blade of a gas turbine and configured to properly keep a gap at a tip end of the moving blade is typically called a shroud. In the gas turbine, the shroud of the turbine is to have very high heat resistance. Proposed as one of solutions to this is the use of a ceramic matrix composite (CMC) having higher heat resistance than metal materials.

#PTL 1: U.S. Patent Application Publication No. 2004/47726, Specification

#FIG. 1 is a schematic sectional view of a gas turbine at which a shroud assembly is provided.

#FIG. 2 is an exploded perspective view of the shroud assembly according to Embodiment 1.

#FIG. 3 is a sectional view of a shroud main body shown in FIG. 2.

#Hereinafter, embodiments will be described with reference to the drawings.

#FIG. 1 is a schematic sectional view of a gas turbine 1 at which a shroud assembly is provided. As shown in FIG. 1, in the gas turbine 1, air introduced from an outside is compressed in a compressor 2 and is then introduced to a combustor 3. A fuel is combusted in the combustor 3 together with the compressed air, and energy of the obtained high-temperature and high-pressure combustion gas is taken out as shaft torque (rotational power) in a turbine 4. The turbine 4 and the compressor 2 are coupled to each other through a rotating shaft 7, and the turbine 4 drives the compressor 2 (and a fan F). There are various types of gas turbines. For example, according to a turbo fan engine, a fan is driven mainly by power collected by a turbine, and an engine output is obtained as thrust. Such turbo fan engine is used as an aircraft engine. FIG. 1 shows the turbo fan engine that is one example of the gas turbine. However, the present invention is not limited to this.

#A below-described heat-resistant shroud assembly 10 (see FIG. 2) is provided at the turbine 4. The shroud assembly 10 is arranged at an inner peripheral surface side of a cylindrical casing 5 of the turbine 4 so as to be opposed to a radially outer tip end of a moving blade 6. The gas turbine 1 may have an active clearance control function of controlling a tip clearance of the moving blade 6. There are various types of active clearance control functions. For example, the active clearance control function can be realized in such a manner that the casing 5 is forcibly contracted by spraying cooling air to an outer periphery of the casing 5 while the gas turbine 1 is driving.