초록 ▼

A passive clearance control system is provided in the turbine section of a gas turbine engine in which turbine casing nozzle vanes and rotor blades are provided. The rotor blades are arranged on a rotor and preferably fitted with a shroud. The tips of the blades or shroud are surrounded by shroud se

A passive clearance control system is provided in the turbine section of a gas turbine engine in which turbine casing nozzle vanes and rotor blades are provided. The rotor blades are arranged on a rotor and preferably fitted with a shroud. The tips of the blades or shroud are surrounded by shroud segments suspended in the turbine casing, and a clearance between the tips and the shroud segments is formed and has a width which is controlled by a heating-cooling channel system. The channel system is supplied with a stream of air from the compressor section of the gas turbine and bypasses the combustion chamber to reach, via a plurality of metering holes, an annulus bounded by a stator ring. In a preferred aspect of the present invention, a ring-shaped orifice plate interacting with the metering holes is provided within the annulus which closes these metering holes to a varying degree depending on the temperature of the air stream reaching the heating-cooling channel system. A fraction of the hot gas flowing across the nozzle vanes and rotor blades is allowed to reach the annulus via a clearance between the stator ring and the stator shroud segments at least at a low turbine load.

대표청구항 ▼

[ What is claimed is:] [1.] Passive clearance control system in the turbine section of a gas turbine including a turbine casing in which, in addition to nozzle vanes, rotor blades are provided, said rotor blades being arranged on a rotor and preferably having a shroud, tips of said shroud being surr

[ What is claimed is:] [1.] Passive clearance control system in the turbine section of a gas turbine including a turbine casing in which, in addition to nozzle vanes, rotor blades are provided, said rotor blades being arranged on a rotor and preferably having a shroud, tips of said shroud being surrounded by stator shroud segments suspended in the turbine casing and forming a clearance with a width which is controlled by a heating-cooling channel system, said heating-cooling channel system being supplied with air from an air stream from a compressor section of the gas turbine and bypassing a combustion chamber of the gas turbine, said air stream reaching an annulus, which is bounded by a stator ring, via a plurality of metering holes, said passive clearance control system comprising:a ring-shaped orifice plate interacting with the metering holes, said orifice plate closing said metering holes to varying degrees as a function of the temperature of the air stream reaching said metering holes,wherein a fraction of hot gas flowing across the nozzle vanes and the rotor blades is allowed to reach an aft portion of the annulus, when viewed in a direction of flow through the gas turbine, via a clearance between the stator ring and the stator shroud segments in a low-load turbine operation.