Gas Turbine Compressor Variable Geometry Control Using Mass Flow Feedback
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Solution Overview
Problem
Existing control methods for variable geometry elements in gas turbine engine compressors suffer from inaccuracies, leading to performance losses due to safety margins, as they rely on imperfect data and sensor limitations, which are not adequately addressed by existing systems like US 5042245 A and US 2021/285386 A1.
Innovation Solution
A method and system for controlling the geometrical configuration of variable geometry elements using a variable geometry element controller that synthesizes mass flow rate and other parameters, allowing precise adjustment of compressor stages to optimize efficiency while minimizing safety margins by using synthetic values and iterative correction processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If variable geometry elements are controlled using traditional methods with safety margins, then reliability is improved by avoiding surge and stall, but compressor performance is worsened due to performance sacrifices
Solution Approach 1:
The patent implements a feedback control system that continuously monitors actual compressor operating conditions (mass flow rate, pressure ratio, rotor speed) and adjusts variable geometry element positioning accordingly. The controller receives feedback from sensors measuring operating parameters and modifies vane angles in real-time to maintain optimal operation near surge and stall boundaries, eliminating the need for conservative safety margins while preserving reliability.
Solution Approach 2:
The system dynamically changes geometric parameters of the compressor (vane angles, passage areas) based on real-time operating conditions. By continuously adjusting these parameters according to actual mass flow rate and pressure ratio measurements, the compressor can operate efficiently across varying conditions without requiring fixed safety margins, thus maintaining reliability while improving overall performance.
2Reliability
If safety margins are increased to compensate for control inaccuracy, then reliability is improved, but compressor efficiency is worsened due to performance loss
Solution Approach 1:
The feedback control system continuously monitors actual operating conditions and adjusts variable geometry element positioning in real-time, eliminating the need for conservative safety margins. By maintaining accurate knowledge of the actual operating point through continuous feedback, the system can operate close to theoretical limits without sacrificing reliability, thereby reducing energy losses associated with conservative positioning.
Solution Approach 2:
The patent replaces traditional mechanical control systems with fixed safety margins with an electronic control system that uses sensors and actuators. This substitution enables dynamic adjustment of geometry based on actual conditions, providing superior control accuracy without the energy penalties of conservative mechanical positioning strategies.
3Reliability
If mass flow along the main gas path is limited to prevent choking, then reliability is improved by avoiding aerodynamic behavior, but productivity is worsened due to reduced mass flow
Solution Approach 1:
The system dynamically adjusts the geometry of compressor stages in real-time based on actual operating conditions. By continuously modifying passage areas and flow angles according to measured mass flow rate and pressure ratio, the compressor can operate at higher mass flows without encountering choke conditions or unwanted aerodynamic behaviors, thus improving productivity while maintaining reliability.
Solution Approach 2:
The control system changes geometric parameters (vane angles, passage cross-sections) dynamically to optimize mass flow capacity. By adjusting these parameters in response to actual operating conditions, the system can safely operate at higher mass flow rates that would otherwise cause choking, thereby increasing productivity without sacrificing reliability.
Data Source
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AI summary
The method can include determining (401) a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing (414) the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.