Cooling of gas turbine shroud rings
AssigneeROLLS-ROYCE plc
InventorPeter A. Damiral
Life of this patent
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Abstract
A gas turbine engine is provided with an annular array of rotor blades which are surrounded by a shroud ring. The shroud ring includes a number of adjacent heat pipes which are of the variable conductance type. The heat pipes each have a portion which is externally of the shroud ring which portion is in turn divided into two parts. The first part is exposed to a flow of cooling air while the second part contains a buffer which operationally varies the conductance of the heat pipe, in accordance with the temperature of air which is tapped from the high pressure compressor of the engine. This serves to ensure that the shroud ring remains substantially isothermal and provides control over the clearance between the tips of the rotary blades and the shroud ring through thermal control of the shroud ring.
Claims8
A gas turbine engine including a turbine having an annular gas passage extending therethrough, an annular array of rotor blades mounted for rotation within said gas passage, and a shroud ring surrounding said array of rotor blades and mounted generally concentric therewith, said shroud ring defining a portion of the radially outer extent of said gas passage through said turbine and including a plurality of adjacent, variable conductance heat pipes, each having first and second portions which are respectively located internally and externally of said shroud ring, each of said externally located heat pipe portions being divided into first and second parts, said first part being contiguous with the respective heatpipe portion internal of said shroud ring, means for directing a flow of cooling fluid over the first parts of the externally located heatpipe portions during operation of said engine, and the second part of each externally located heat pipe portion being so located as not to be exposed to said cooling fluid and comprising buffering means to operationally vary the heat conducting characteristic of said heat pipe with the magnitude of an operationally variable characteristic of said engine.
Dependencies are inferred from the claim text.