Fuel Injector Steam Radial Buffer for Gas Turbine Flashback

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Solution Overview

Problem

Current systems for utilizing steam in gas turbine engines, particularly those fueled with hydrogen, face inefficiencies in mixing and combustion due to lack of effective radial buffering between fuel and air flows, leading to potential flashback and incomplete combustion.

Innovation Solution

The fuel injector assembly incorporates a steam passage that circumscribes both the fuel and air flows, providing a radial buffer and delaying their mixing, while the air and fuel are swirled in the same direction to enhance penetration into the combustion chamber and reduce turbulence-induced mixing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If fuel and air are mixed directly without radial buffering, then mixing efficiency is improved, but flashback risk increases and combustion completeness deteriorates

Engineering Contradiction:
Improvemixing efficiencyVSAvoidflashback prevention
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The steam passage introduces steam as an intermediary substance between the fuel and air flows. The steam acts as a buffer that delays direct contact between fuel and air, preventing flashback while ultimately enabling complete combustion. The steam flow mediates the interaction between fuel and air by providing a transitional zone that controls mixing timing and location.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If steam is introduced to buffer fuel and air flows, then flashback is reduced, but device complexity increases

Engineering Contradiction:
Improveflashback preventionVSAvoidfuel injector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The steam passage is nested within the existing fuel injector assembly, with the steam flow path concentrically arranged around the fuel passage. This nested configuration allows the steam buffering function to be integrated into the existing injector structure without requiring separate external components, thereby minimizing the increase in device complexity while achieving flashback prevention.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Length of moving object

If air and fuel are swirled in the same direction, then penetration into combustion chamber is improved, but turbulence-induced mixing increases

Engineering Contradiction:
Improvepenetration depthVSAvoidmixing rate
Core Design Contradiction:
Length of moving objectVSQuantity of substance

Solution Approach 1:

The swirler structures are configured to impart swirl to both air and fuel flows before they enter the main combustion zone. This preliminary swirling action establishes coherent rotational motion that enhances penetration depth into the combustion chamber. The steam buffer then acts to control the subsequent mixing rate, preventing excessive turbulence-induced mixing while maintaining the beneficial penetration effects of the preliminary swirl.

Inventive Principle:
Principle #10Preliminary 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

This configuration improves combustion efficiency by delaying fuel-air mixing, reducing the likelihood of flashback, and ensuring complete burning of hydrogen fuel, even with its fast flame speed, while maintaining effective mixing and burning of traditional hydrocarbon fuels.

Implementation Method 1

The steam flow circumscribes the fuel flow and provides a radial buffer between the fuel flow and the air flow

Methodology Applied
Scientific EffectRadial buffering:

Implementation Method 2

the air and fuel are swirled in the same direction to enhance penetration into the combustion chamber

Methodology Applied
Scientific EffectSwirling flow: Vortex Ring

Implementation Method 3

reducing turbulence-induced mixing

Methodology Applied
Scientific EffectTurbulence reduction: Turbulence

Data Source

PatentEP4431813A1Fuel injector assembly for gas turbine engine
Publication Date: 2024.09.18 RTX CORP
  • EP4431813A1 patent drawingFigure 1
  • EP4431813A1 patent drawingFigure 2
  • EP4431813A1 patent drawingFigure 3

AI summary

An assembly is provided for a turbine engine (20). This assembly includes a fuel injector assembly (62), and the fuel injector assembly (62) includes a fuel passage (114), an air passage (160) and a steam passage (118). The fuel injector assembly (62) is configured to direct fuel out of the fuel passage (114) along an axis (72) into a volume (58) as a fuel flow. The fuel injector assembly (62) is configured to direct air out of the air passage (160) along the axis (72) into the volume (58) as an air flow, where the air flow circumscribes the fuel flow. The fuel injector assembly (62) is configured to direct steam out of the steam passage (118) along the axis (72) into the volume (58) as a steam flow, where the steam flow circumscribes the fuel flow and provides a radial buffer between the fuel flow and the air flow.