Method and System for Controlling Gas Turbine Performance With a Variable Backflow Margin

摘要

A system and method for controlling the performance of a gas turbine system is provided. A backflow margin pressure ratio for a component is determined. A modified backflow margin pressure ratio for the component is calculated based on the number of fired hours and starts. Bleed air along a first flow path is controlled based on the modified backflow margin pressure ratio.

主权项

1. A method for controlling a gas turbine having a compressor, a combustor and a turbine, the method comprising:
determining a backflow margin pressure ratio for a component of the turbine; determining a modified backflow margin pressure ratio for the component based on a number of fired hours and starts; selectively extracting a stream of bleed air from a stage of the compressor; flowing at least a portion of the stream of bleed air through a first flow path from the compressor towards the component; and controlling the stream of bleed air along the first flow path to selectively control an air pressure at a cavity of the component based on the modified backflow margin pressure ratio.