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US 5,385,012 AGranted
Bleed valve control
AssigneeROLLS-ROYCE plc
InventorArthur L. Rowe
Life of this patent
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AssigneeROLLS-ROYCE plc
InventorArthur L. Rowe
Estimating the term…
A method and means are provided for operating a bleed to counter surge in the compressor of a gas turbine. A number of engine condition parameters which are precursors to a change of engine running conditions are monitored to detect changes outside predetermined limits. The method includes deriving a measure of heat soakage effects as an engine condition parameter by monitoring a gas flow value such as compressor outlet pressure, and deriving a further engine condition parameter by evaluating changes of engine power-setting by comparing instantaneous power-setting commands with lagged values of power-setting commands. If over-limit values of a monitored engine condition parameter are detected the bleed is opened and the bleed is maintained open if monitored changes of an engine operational parameter (such as compressor speed) exceed predetermined limits within a predetermined period of the opening of the bleed by an over-limit engine condition parameter.
A method of controlling a compressor bleed valve in a gas turbine engine for a flow of gas from a high pressure region of the compressor to counter compressor surge, said method comprising monitoring one or more properties of the gas flow as an engine condition parameter to obtain a measure of heat soakage effects produced in the compressor by adjustment of relative temperatures between the gas flow and the compressor parts during deceleration of the engine, and the detection of values of said parameter outside a predetermined limit causing said bleed valve to open by opening the bleed valve in response to detected values of said parameter outside a predetermined limit.
A pressure bleed control arrangement for the compressor of a gas turbine engine comprising means for monitoring one or more properties of the gas flow as an engine condition parameter to obtain a measure of heat soakage effects produced in the compressor by adjustment of relative temperatures between the gas flow and the compressor parts during deceleration of the engine, and means for actuating the opening of the compressor bleed in response to the sensing of a predetermined limit value of said gas flow property or properties.
Dependencies are inferred from the claim text.