US 6,141,951 A · Control system for modulating bleed in response to engine usage

Abstract

A control system for operating a compressor bleed valve in a gas turbine engine to prevent compressor operation in surge region determines engine stability in response to a plurality of sensed engine parameters, and calculates and stores engine parameters to estimate compressor performance relative to a stability limit which is indicative of a surge operation. The control system further maintains a rolling average of the estimate of compressor performance for up to a predetermined number of engine flights. This rolling average of the estimate of compressor performance is indicative of engine usage and associated engine degradation. The control system determines a bias for the bleed valve in response to calculated engine parameters and adjusts the operation of the bleed valve in response to the compressor performance so as not to exceed the stability limit.

Claims18

Dependent claims

A method for controlling the operation of a bleed valve in a compressor that is a part of a gas turbine engine, the method comprising the steps of:

determining an engine stability condition in response to at least one sensed engine parameter;
estimating, in response to the determined engine stability condition, compressor performance relative to a stability limit indicative of surge operation;
maintaining, in response to the estimated compressor performance, a rolling average of the estimate of the compressor performance, wherein the rolling average of the estimate is indicative of the usage of the engine over a plurality of engine operations;
and
calculating, in response to the estimate of compressor performance and the rolling average of the estimate, a bias to modulate the operation of the bleed valve and for commanding the bleed valve to a desired position, wherein the commanded bleed valve position is responsive to the usage of the engine to prevent compressor operation in a surge region.

2 more elements

A control system for operating a bleed valve in a compressor that is a part of a gas turbine engine, comprising:

stability means for determining engine stability in response to at least one sensed engine parameter and for providing a signal indicative of sensed engine stability;
estimating means, responsive to the sensed engine stability signal, for estimating compressor performance based on at least one calculated engine parameter and for providing at least one signal indicative of the estimate of compressor performance;
maintenance means, responsive to the at least one estimate of compressor performance signal, for maintaining a rolling average of the estimate of the compressor performance and for providing a rolling average signal indicative thereof, wherein the rolling average signal is indicative of the usage of the engine over a plurality of engine operations;
and
calculating means, responsive to the at least one estimate of compressor performance signal and the rolling average signal, for calculating a bias to modulate the operation of the bleed valve and for providing a calculated bias signal indicative of a commanded bleed valve position, wherein the commanded bleed valve position is responsive to the usage of the engine to prevent compressor operation in a surge region.

2 more elements

Dependencies are inferred from the claim text.

Control system for modulating bleed in response to engine usage

Life of this patent

Control system for modulating bleed in response to engine usage

Life of this patent

Abstract

Claims18