Gas Turbine EGR Feedback Damping at the Compressor Inlet

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Solution Overview

Problem

Gas turbine engines waste a significant amount of exhaust gas, which could be productively utilized to improve combustion operability and load efficiency.

Innovation Solution

A system and method for recirculating exhaust gases through an exhaust gas recirculation (EGR) system, using sensors and dampers to control the injection of exhaust gas into the compressor inlet, allowing for modulation based on sensed characteristics to maintain optimal operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If exhaust gas is recirculated to the compressor inlet to improve combustion operability and load efficiency, then combustion control and engine efficiency are improved, but the complexity of the EGR system increases due to additional sensors and dampers

Engineering Contradiction:
Improvecombustion operability and load efficiencyVSAvoidEGR system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system employs inlet sensors to continuously monitor characteristics (temperature, pressure, flow rate, humidity) of the air-fuel mixture at the compressor inlet, and a controller uses this feedback data to dynamically adjust damper positions and EGR injection rates, optimizing combustion operability and load efficiency under varying operating conditions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The EGR system uses actuatable dampers that can dynamically adjust their opening degrees based on real-time sensor data, allowing the system to adapt the amount of exhaust gas recirculated to match changing engine operating conditions and maintain optimal combustion characteristics

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If exhaust gas is injected into the compressor inlet to control temperature, then combustion control is improved, but the risk of harmful effects increases due to potential overheating or improper mixture composition

Engineering Contradiction:
Improvecombustion controlVSAvoidoverheating and mixture composition issues
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

Inlet sensors continuously monitor temperature, pressure, flow rate, and humidity at the compressor inlet, providing real-time feedback to the controller which adjusts EGR injection rates and damper positions to maintain safe operating temperatures and proper mixture composition, preventing overheating and combustion issues

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes operating parameters such as EGR injection rate, damper position, and air-fuel mixture composition based on sensor readings, adjusting these parameters to maintain optimal combustion conditions while avoiding harmful effects like overheating or improper mixture ratios

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances gas turbine engine efficiency and flexibility by effectively utilizing recycled exhaust gas for improved combustion control, maintaining desired operating conditions and reducing emissions.

Implementation Method 1

an exhaust gas recirculation (EGR) system configured to recirculate the exhaust gas along an exhaust recirculation path from the turbine to an inlet of the compressor

Methodology Applied
Scientific EffectExhaust gas recirculation:

Implementation Method 2

an inlet sensor disposed adjacent to the inlet of the compressor, the inlet sensor configured to detect one or more characteristics at the inlet

Methodology Applied
Scientific EffectSensor detection:

Implementation Method 3

one or more dampers disposed along the exhaust recirculation path and actuatable between open and closed positions

Methodology Applied
Scientific EffectDamper actuation:

Implementation Method 4

a compressor configured to compress and supply the oxidant to the combustor

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 5

a combustor configured to receive and combust a fuel with an oxidant

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 6

a turbine driven by combustion products from the combustor

Methodology Applied
Scientific EffectTurbine expansion: Turbine

Data Source

PatentEP4663915A1System and method for operating exhaust gas recirculation in gas turbines
Publication Date: 2025.12.17 GENERAL ELECTRIC TECH GMBH
  • EP4663915A1 patent drawingFigure 1
  • EP4663915A1 patent drawingFigure 2
  • EP4663915A1 patent drawingFigure 3~4

AI summary

A system (10) including a gas turbine system (52) including a compressor (152) configured to compress an oxidant (68); a combustor (154) configured to receive and combust a fuel (70); a turbine (156) driven by combustion products (172) from the combustor (154); an exhaust gas recirculation system (54) configured to recirculate exhaust gas (66) along an exhaust recirculation path (220); and an inlet sensor (278) adjacent to the inlet (184) of the compressor (152), the inlet sensor (278) detects one or more characteristics; a generator driven by the turbine (156), wherein the generator generates electrical power and exports to an electrical grid; and a control system including: one or more dampers (202, 210, 224, 240, 244, 258) along the exhaust recirculation path (220) and actuatable between open and closed positions; and a controller (214) configured to receive sensor data, the sensor data associated with a characteristic at the inlet (184); and modulate at least one of the dampers (202, 210, 224, 240, 244, 258) based on the received sensor data to control an amount of exhaust gas (66) injected into the compressor (152).