Hydrogen Fuel Nozzle Assembly With Steam Mixing for Flashback Control

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Solution Overview

Problem

Turbine engines using hydrocarbon fuels produce environmentally harmful by-products such as NOx, CO, UHC, and sulfur oxides, while hydrogen fuel poses risks of flashback and flameholding due to its faster burning velocity and wider flammable range.

Innovation Solution

Introduce steam into the fuel nozzle assembly to mix with hydrogen before combustion, controlling flame speed and reducing peak temperatures, thereby limiting flashback and NOx emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If hydrogen fuel is used instead of hydrocarbon fuel, then NOx emissions are reduced, but flashback and flameholding risks increase due to faster burning velocity

Engineering Contradiction:
ImproveNOx emissionsVSAvoidflashback and flameholding risks
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent introduces steam as an intermediary substance mixed with hydrogen fuel in the fuel nozzle assembly. The steam acts as a moderating agent that reduces the burning velocity of hydrogen while maintaining combustion efficiency. This intermediary approach allows the system to benefit from hydrogen's low emissions while mitigating its safety risks through controlled mixing ratios and injection timing

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical and chemical parameters of the fuel by mixing steam with hydrogen. This parameter change modifies the fuel's burning characteristics, specifically reducing flame speed and controlling flammability range. The steam-hydrogen mixture creates a controlled combustion process that maintains the environmental benefits of hydrogen while adjusting the combustion parameters to prevent flashback and flameholding

Inventive Principle:
Principle #35Parameter changes

2Reliability

If steam is mixed with hydrogen to control flame speed, then flashback is prevented, but combustion efficiency may be reduced

Engineering Contradiction:
Improveflashback preventionVSAvoidcombustion efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by introducing steam in controlled, specific amounts rather than complete saturation. The steam-to-hydrogen ratio is optimized to provide just enough moderation to prevent flashback while maintaining sufficient combustion efficiency. This partial mixing approach ensures that the fuel mixture retains adequate energy content while achieving the safety threshold for flashback prevention

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent ensures continuous useful action by maintaining optimal steam-hydrogen mixing throughout the combustion process. The fuel nozzle assembly continuously introduces the right proportion of steam to maintain safe combustion characteristics across varying operating conditions. This continuous control ensures that combustion efficiency is maintained while flashback prevention is sustained throughout engine operation

Inventive Principle:
Principle #20Continuity of useful action

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 steam-hydrogen mixture reduces NOx emissions and limits flame spread, minimizing wall and liner temperatures, and prevents flashback and flameholding, making it suitable for hydrogen fuel use without diluents.

Implementation Method 1

Gaseous fuel, including hydrogen, spreads/disperses at a faster rate than atomized liquid fuel

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

Hydrogen or hydrogen mixed with another element has a higher flame temperature than traditional hydrocarbon fuels

Methodology Applied
Scientific EffectThermal dilution:

Data Source

PatentEP4678892A1Gas turbine engine and fuel nozzle assembly therefor
Publication Date: 2026.01.14 GENERAL ELECTRIC CO
  • EP4678892A1 patent drawingFigure 1
  • EP4678892A1 patent drawingFigure 2
  • EP4678892A1 patent drawingFigure 3

AI summary

A gas turbine engine (10), comprising a compressor section (12), combustion section (14), and turbine section (16) in serial flow arrangement, with the combustion section (14) comprising: a combustor (30) liner that at least partially defines a combustion chamber (50); and a gaseous fuel nozzle assembly (48, 248, 448, 648, 848), comprising: a steam supply (36) to supply steam; a hydrogen fuel supply (34) to supply gaseous hydrogen fuel; and a fuel nozzle body (49, 249, 449, 649, 849) fluidly coupled with the steam supply (36) and the hydrogen fuel supply (34) to provide the steam and the gaseous hydrogen fuel to the combustion chamber (50) to limit a flame speed in the combustion chamber (50).