In-line Injector Burner for Gas Turbine Flashback Prevention

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Solution Overview

Problem

Existing burner assemblies for gas turbine engines face challenges when using highly reactive fuels like hydrogen, as crossflow injection can lead to vortices, low velocity regions, and increased risk of flame holding or flashback.

Innovation Solution

A burner assembly with a diagonal swirler and in-line injectors configured to discharge fuel in the flow direction of air, reducing vortices and ensuring consistent fuel delivery, thereby minimizing the risk of flame hold or flashback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If crossflow injection is used to achieve efficient mixing of air and fuel, then mixing efficiency is improved, but vortices and low velocity regions are created which increase the risk of flame holding or flashback

Engineering Contradiction:
Improvemixing efficiencyVSAvoidrisk of flame holding or flashback
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent inverts the conventional crossflow injection approach by using in-line injection where fuel is injected parallel to the air flow direction rather than perpendicular to it. This inversion eliminates the formation of vortices and low velocity regions while maintaining efficient mixing through the diagonal swirler configuration.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the injection parameter from crossflow (perpendicular injection) to in-line (parallel injection), and modifies the swirler geometry to a diagonal configuration. These parameter changes achieve efficient mixing without creating harmful vortices and low velocity regions.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If crossflow injection is used, then mixing is achieved, but the system becomes sensitive to momentum flux ratio changes associated with fuels of different Wobbe Index

Engineering Contradiction:
Improvemixing capabilityVSAvoidsensitivity to fuel variations
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The diagonal swirler with in-line injectors creates a universal mixing system that is less sensitive to fuel variations. The diagonal blade configuration and in-line injection approach provide consistent mixing performance across different fuel types and Wobbe Indices, making the burner assembly more versatile and adaptable.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If multiple injectors or burners are equipped to accept hydrogen, then fuel flexibility is improved, but device complexity increases

Engineering Contradiction:
Improvefuel flexibilityVSAvoidnumber of injectors or burners
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The burner assembly is segmented into multiple diagonal burners, each equipped with in-line injectors. This segmentation allows flexible fuel selection while maintaining a relatively simple overall structure. Each modular burner unit can independently handle different fuel types including hydrogen.

Inventive Principle:
Principle #1Segmentation

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 burner assembly effectively operates with hydrogen and other fuels, reducing the risk of flame hold or flashback and maintaining sufficient flow velocity for efficient combustion across a range of operating conditions.

Implementation Method 1

a swirler, having a plurality of blades circumferentially distributed around the burner axis, wherein mixing channels are defined between respective pairs of adjacent blades

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Implementation Method 2

cause a rotation around the burner axis of air flowing therethrough

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

a plurality of in-line injectors, arranged at inlet sections of respective mixing channels and having respective in-line nozzles, configured to discharge in a respective flow direction of a fluid flowing through the respective mixing channel

Methodology Applied
Scientific EffectIn-line injection: Injector

Implementation Method 4

an annular space is defined between the frustoconical outer surface of the inner body and the frustoconical inner surface of the outer body

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4206535B1Burner assembly with in-line injectors
Publication Date: 2025.02.19 ANSALDO ENERGIA SWITZERLAND AG
  • EP4206535B1 patent drawingFigure 1
  • EP4206535B1 patent drawingFigure 2
  • EP4206535B1 patent drawingFigure 3~4

AI summary

A burner assembly for a heavy-duty gas turbine engine has a main burner (15), extending around a burner axis (B) and including: a swirler (7), having a plurality of blades (24) circumferentially distributed around the burner axis (B), wherein mixing channels (25) are defined between respective pairs of adjacent blades (24); a plurality of in-line injectors (35), arranged at inlet sections of respective mixing channels (25) and having respective in-line nozzles (36), configured to discharge in a respective flow direction (F) of a fluid flowing through the respective mixing channel (25) .