Gas Turbine Combustor Dilution Passages for Hydrogen-Fuel Heat Control

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Solution Overview

Problem

Gas turbine engines produce harmful emissions such as NOx, CO, UHC, and SOx, and existing combustors struggle to effectively manage these by-products while efficiently utilizing hydrogen-containing fuels that have faster burn temperatures.

Innovation Solution

A combustor design with dilution passages in the dome wall that shape and direct the flame using angled slots and air curtains to insulate and cool the combustor components, allowing for the use of hydrogen-containing fuels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If hydrogen-containing fuels are used in the combustor, then burn temperature and efficiency are improved, but risk of overheating and damage to combustor components increases

Engineering Contradiction:
Improveburn temperatureVSAvoidrisk of overheating and damage
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

A film of dilution air is introduced as an intermediary substance between the hydrogen-containing fuel flame and the combustor components (dome wall, liner). This air film acts as a thermal barrier that absorbs and carries heat away from the components, preventing overheating while allowing the high-temperature combustion to proceed efficiently

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention uses pneumatic flow of dilution air through specifically designed passages and slots to create a protective film. The air is delivered through domed walls, liners, and slots at controlled locations to form a continuous protective barrier that physically separates the hot combustion gases from the combustor structure

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If dilution air is introduced to cool combustor components, then component temperature is reduced, but flame control and combustion efficiency may deteriorate

Engineering Contradiction:
Improvecomponent temperatureVSAvoidcombustion efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The dilution air is not introduced uniformly throughout the combustor but at specific localized positions through domed walls, liners, and slots. The air is delivered where it is most needed - at the interface between the flame and combustor components - while avoiding interference with the main combustion zone, thus protecting components without sacrificing combustion efficiency

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention introduces a controlled amount of dilution air - enough to form a protective film on combustor components but not so much as to significantly cool the combustion gases or interfere with combustion. The air is delivered at optimized rates and locations to achieve partial cooling where needed while maintaining overall combustion efficiency

Inventive Principle:
Principle #16Partial or excessive 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 design effectively reduces the risk of overheating and damage to combustor components, enhances flame control, and supports the use of high-temperature fuels like hydrogen, minimizing emissions and improving engine performance.

Implementation Method 1

A flow of compressed air is directed through the plurality of dilution passages. The curtain of compressed air from the dilution passages insulates and cools the combustor components, including the dome wall, inner liner, and outer liner

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

The curtain of compressed air from the dilution passages insulates and cools the combustor components, including the dome wall, inner liner, and outer liner

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4357674B1Gas turbine engine combustor with dilution passages
Publication Date: 2025.10.29 GENERAL ELECTRIC CO
  • EP4357674B1 patent drawingFigure 1
  • EP4357674B1 patent drawingFigure 2
  • EP4357674B1 patent drawingFigure 3

AI summary

A combustor including an annular liner (206, 208), a dome wall (202), a combustion chamber, at least one fuel cup (204) and at least one dilution passage (212). The fuel cup (204) being provided on the dome wall (202) and being fluidly coupled to the combustion chamber. The fuel cup (204) defining a fuel cup centerline (210). The at least on dilution passage (212) terminating in at least on slot (214) opening onto the dome wall (202), with the slot (214) having a longitudinal body axis (216).