Air delivery system for regulating thermal growth
AssigneeGeneral Electric Company
InventorsJoseph P. Smith, Jr., Robert L. Mentzer, Dana D. Freberg
Life of this patent
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Abstract
A timing valve is responsive to certain hydraulic rotor speed input signals so as to schedule increased temperatures of air to a turbine shroud support in accordance with the thermal time constants of the rotor. Clearance between the rotor and the shroud is thereby minimized during both transient and steady-state operating conditions. Temperatures are incrementally increased by selectively combining air from the compressor fifth and ninth stage bleed manifolds. Under certain operating conditions, the timing valve is pre-empted and air is provided at a predetermined temperature level as a function of rotor speed only.
Claims23
In combination with apparatus of the type having a compressor, a rotor, a shroud, a shroud support surrounding the rotor, an air delivery system for providing air at varying temperatures to the shroud support comprising:
- (a) first and second air sources, the temperature of said second air source being higher than that of said first air source;
- (b) first and second air valves for controlling the flow of air from said first and second air sources, respectively, to a manifold;
- (c) means for delivering air from the manifold to the support;
- and
- (d) valve means responsive to the speed of said rotor and to the time after reaching predetermined rotor speeds for operating said first and second air valves, said valve means including a timer valve which is activated when the speed of the rotor reaches a predetermined level with said timer valve including a piston which advances at a first substantially constant rate of speed upon receiving a first predetermined rotor speed signal and which retracts at a second substantially constant rate of speed upon receiving a second predetermined rotor speed signal, wherein said valve means operates said first and second air valves in response to translation of said piston.
In combination with apparatus of the type having a compressor, a variable speed rotor, a shroud, a shroud support surrounding the rotor, an improved air delivery system for supplying air flow to the shroud support in response to the rotor speed wherein the improvement comprises:
- (a) air valve means for selectively modulating the temperature of the air;
- (b) means for timing the operation of the rotor after its acceleration to a predetermined level of operation, said means including a piston responsive to rotor speed which advances at a first predetermined speed when the rotor accelerates to a predetermined level of operation and retracts at a second predetermined speed when the rotor decelerates to a predetermined level of operation;
- and
- (c) means for modulating said air valve means in response to translation of said piston of said timing means.
Dependencies are inferred from the claim text.