Staged Axially Offset Combustor for Gas Turbine Emission Control

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Solution Overview

Problem

Gas turbine engines face challenges in maintaining optimal combustion efficiency and emission control across varying power settings, particularly in harsh environments where uneven fuel distribution can lead to hot flame streaks and high emissions.

Innovation Solution

A gas turbine combustor dome assembly with multiple fuel/air mixer assemblies arranged in a ring configuration, where some mixer assemblies are recessed, allowing for independent fuel supply to different stages, ensuring stable flame quality and efficient combustion by confining the flame and minimizing interference from airflow during low-power operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If all fuel stages are turned on during high-power operation, then fuel distribution is even and emissions are minimized, but device complexity increases due to multiple independently controllable stages

Engineering Contradiction:
Improveemissions and hot flame streaksVSAvoidmultiple independently controllable stages
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The combustor is divided into multiple axially offset stages with separate fuel injectors and mixer elements. Each stage can be independently controlled to provide even fuel distribution during high-power operation, minimizing emissions and hot flame streaks while maintaining manageable system complexity through modular design

Inventive Principle:
Principle #1Segmentation

2Device complexity

If only one or some stages are turned on during low-power operation, then device complexity is reduced, but flame quality and combustion stability deteriorate due to uneven fuel distribution

Engineering Contradiction:
Improvenumber of active fuel stagesVSAvoidcombustion stability and efficiency
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

Different stages are positioned at different axial locations with specific mixer element configurations optimized for their operating conditions. During low-power operation, selected stages can be activated to provide locally optimized combustion characteristics, maintaining flame quality and stability while reducing the number of active stages

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Stages are arranged in axial offset positions rather than a single plane, creating a three-dimensional combustion structure. This axial distribution allows selective activation of specific axial zones during low-power operation, maintaining combustion stability while simplifying control by deactivating entire axial sections

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If fuel injectors are positioned in a single plane, then device complexity is reduced, but combustion efficiency decreases due to turbulence and quenching from airflow interference

Engineering Contradiction:
Improvesingle plane configurationVSAvoidcombustion efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

Fuel injectors and mixer elements are arranged in multiple axially offset planes rather than a single plane. This three-dimensional configuration positions fuel injection zones at different axial locations, reducing turbulence and quenching effects from airflow interference while maintaining a relatively simple overall structure

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This configuration enhances flame stability and combustion efficiency by locally confining the flame during low-power operation, reducing the risk of turbulence and quenching, and allows for even fuel distribution during high-power operation, minimizing emissions and hot flame streaks.

Implementation Method 1

each first mixer element defining an air flow passage therethrough and each second mixer element defining an air flow passage therethrough

Methodology Applied
Scientific EffectMixing:

Implementation Method 2

burning a fuel and air mixture at an outlet of a second, adjacent fuel/air mixer assembly

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3099979B1Combustor with staged, axially offset combustion
Publication Date: 2019.03.13 WOODWARD INC
  • EP3099979B1 patent drawingFigure 1
  • EP3099979B1 patent drawingFigure 2A
  • EP3099979B1 patent drawingFigure 2B

AI summary

In some aspects, a gas turbine combustor assembly is arranged around a longitudinal axis. The gas turbine combustor comprises a first fuel/air mixer assembly, the mixer assembly comprising a first fuel injector and a plurality of first mixer elements, each mixer element defining an air flow passage therethrough having an outlet in a first plane. A second fuel/air mixer assembly comprises a second fuel injector and a plurality of second mixer elements, and each second mixer element defines an air flow passage therethrough having an outlet in a second plane, longitudinally offset from the first plane.