Torch Igniter Recirculation Zone for Gas Turbine Combustor

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Solution Overview

Problem

Gas turbine engines face challenges in achieving reliable ignition and flame propagation at lower air pressure drops, especially in cold ambient conditions, due to the need for high energy release and stable combustion across a wide range of operating conditions.

Innovation Solution

The torch igniter system incorporates radial and/or axial air swirler components to create a strong recirculation zone in an auxiliary combustion chamber, optimizing turbulence and swirling to sustain the flame without maintaining the ignition source, and includes a cooling and purge air sub-system to prevent coke formation during shut-down.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional spark igniters are used, then the device complexity is low, but the energy release is insufficient for reliable ignition in cold conditions

Engineering Contradiction:
Improveenergy releaseVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The igniter system is segmented into distinct functional components: an auxiliary combustion chamber for flame generation, a primary combustion chamber for engine ignition, air swirler elements for flow control, and fuel injection systems. This segmentation allows each component to be optimized for its specific function, enabling high energy release in the auxiliary chamber while keeping the overall system manageable through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The auxiliary combustion chamber is nested within or adjacent to the primary combustion chamber, with the air swirler and fuel injection components nested within the combustion chamber structure. This nested arrangement allows the auxiliary combustion system to be integrated into the existing engine architecture, providing enhanced energy release without proportionally increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Stability of the object's composition

If air swirler components are added to create recirculation zone, then flame stability is improved, but device complexity increases

Engineering Contradiction:
Improveflame stabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The air swirler components are designed to generate recirculation zones and stabilize flames through their geometric configuration alone, without requiring external control systems or additional actuators. The swirling flow patterns are self-sustaining once established, providing passive flame stability that reduces control system complexity while maintaining stable combustion across varying operating conditions.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The air swirler geometry is optimized to create specific flow parameters (swirl intensity, recirculation zone size, flow velocity distribution) that naturally stabilize the flame. By carefully selecting geometric parameters such as swirler vane angles, passage cross-sections, and chamber dimensions, the system achieves flame stability through parameter optimization rather than complex control mechanisms.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If near stoichiometric combustion is achieved, then exhaust smoke is reduced, but air flow requirements increase

Engineering Contradiction:
Improveexhaust smokeVSAvoidair flow requirements
Core Design Contradiction:
Object-generated harmful factorsVSQuantity of substance

Solution Approach 1:

The auxiliary combustion chamber operates with near-stoichiometric air-fuel ratios to minimize smoke formation, while the overall system draws air from the engine's existing plenum source. The air flow requirement is partially met by routing a portion of the compressor discharge through the auxiliary chamber, and the remaining requirement is satisfied by the engine's normal air intake, thus achieving clean combustion without proportionally increasing total air flow demands.

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

This solution enhances cold day combustor light-off performance, provides reliable re-light capability, and reduces exhaust smoke by achieving near stoichiometric combustion, resulting in improved flame propagation and energy release within the primary combustor chamber.

Implementation Method 1

optimizing turbulence and swirling to sustain the torch igniter flame

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

radial and/or axial air swirler components to create a strong recirculation zone

Methodology Applied
Scientific EffectVortex flow: Vortex Ring

Implementation Method 3

The torch igniter ignites fuel released by combustor nozzles in a combustor of the engine to produce heated combustion products

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

a cooling and purge air sub-system to prevent coke formation during shut-down

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3183448B1Torch igniter
Publication Date: 2021.01.13 WOODWARD INC
  • EP3183448B1 patent drawingFigure 1
  • EP3183448B1 patent drawingFigure 2A~2C
  • EP3183448B1 patent drawingFigure 3A~3C

AI summary

A gas turbine combustor assembly includes a primary combustion chamber in fluid communication with a primary fuel injector and a primary air inlet. A torch igniter is carried by the primary combustion chamber, and includes an auxiliary combustion chamber housing comprising a mixing chamber and a throat region converging downstream of the mixing chamber. An air swirler including a plurality of swirl openings surrounding an outlet of an auxiliary fuel injector is coupled to the auxiliary combustion chamber proximate the mixing chamber. An ignition source projects into the mixing chamber of the auxiliary combustion chamber.