Staged Combustor Layout for Low-NOx Turbine Combustion

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Solution Overview

Problem

Turbine engines using hydrocarbon fuels or hydrogen-based fuels face challenges in reducing NOx emissions while maintaining efficiency, due to high combustor flame temperatures and undesirable by-products.

Innovation Solution

A combustion section with a primary combustor and a set of secondary combustors, where secondary exhaust gases are directed into the primary combustor at different orientations, reducing oxygen levels and temperatures to lower NOx emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If hydrogen or hydrogen mixed fuel is used for combustion, then burning velocity and flammable range are improved, but flame temperature increases leading to higher NOx emissions

Engineering Contradiction:

Improveburning velocityVSAvoidNOx emissions

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The combustor is divided into multiple zones with different fuel injection points and combustion characteristics. Primary fuel is injected at the center and secondary fuel is injected at the periphery, creating segmented combustion regions that control flame temperature distribution and reduce peak temperatures to lower NOx emissions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the combustor are given different fuel-air mixture qualities. The central region has a rich mixture while the peripheral region has a lean mixture, creating local variations in combustion intensity and temperature that allow high burning velocity in the center while controlling overall NOx formation through cooler peripheral zones

Inventive Principle:

Principle #3Local quality

2Use of energy by moving object

If high combustor flame temperature is maintained for efficiency, then energy conversion is improved, but NOx emissions increase due to high temperature combustion

Engineering Contradiction:

Improvecombustion efficiencyVSAvoidNOx emissions

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The combustion process is segmented into primary combustion zone for efficient energy release and secondary zones for temperature control. This allows maintaining high combustion efficiency in the primary zone while using secondary fuel injection to modulate temperatures and reduce NOx in downstream regions

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fuel-air equivalence ratio is varied spatially throughout the combustor. Rich mixtures (φ>1) are used in the primary combustion zone to maximize energy release, while lean mixtures (φ<1) are used in secondary zones to control peak temperatures and reduce NOx emissions, achieving both efficiency and emission control

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If traditional single combustor design is used, then device complexity is low, but temperature distribution is insufficient leading to higher pollutant emissions

Engineering Contradiction:

Improvecombustor structureVSAvoidpollutant emissions

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The single combustor is segmented into multiple combustion zones with separate fuel injection systems. Primary fuel injectors are positioned at the center while secondary fuel injectors are positioned at the periphery, creating distinct combustion regions that improve temperature distribution and reduce pollutant emissions without requiring multiple separate combustors

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The secondary fuel injection system is nested within the primary combustor structure. The secondary fuel injectors are positioned concentrically around the primary fuel injection point, allowing the secondary combustion zone to nest within the overall combustor volume and achieve improved emission control without significantly increasing external dimensions

Inventive Principle:

Principle #7Nested doll (Nesting)

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

The arrangement of secondary combustors with angled exhausts and staged fueling reduces NOx emissions by improving temperature distribution and completing combustion, achieving lower pollutant levels while maintaining efficiency.

Implementation Method 1

The secondary combustors are arranged to exhaust gasses into the primary combustor... generating secondary exhaust gasses in a set of secondary combustors... The secondary exhaust gasses are introduced into the primary combustion chamber

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS12560324B2Combustion section with a primary combustor and a set of secondary combustors

Publication Date: 2026.02.24 GENERAL ELECTRIC CO

AI summary

A turbine engine with a compressor section, a combustion section, and a turbine section in serial flow arrangement along an engine centerline. A combustion section for the turbine engine, having a primary combustor liner including an inner liner and an outer liner annular about an engine centerline. A dome wall extending between the inner liner and the outer liner. A set of primary dome inlets located in the dome wall and circumferentially arranged about the engine centerline. A set of secondary combustors fluidly coupled to a primary combustion chamber, the set of secondary combustors including a first mini combustor and a second mini combustor.