Torch Ignitor Self-Cleaning via Fuel-Lean Oxidation

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Solution Overview

Problem

Conventional maintenance techniques for torch ignitors in gas turbine engines are inadequate in preventing excessive carbon growth, which can lead to performance deterioration and component erosion due to uncontrolled carbon deposition on internal surfaces.

Innovation Solution

A method involving a fuel-lean flow through the combustion chamber of the torch ignitor, combined with heating of interior surfaces, is used to reactively remove carbon deposits, performed intermittently during flight or as part of engine shutdown and maintenance cycles, with a subsequent air-fuel mixture adjustment to maintain optimal combustion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a torch ignitor operates in a fuel rich mixture for continuous ignition, then reliable ignition is achieved, but carbon deposits accumulate on internal surfaces deteriorating performance

Engineering Contradiction:
Improveignition reliabilityVSAvoidcarbon deposit
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system implements periodic switching between fuel-rich mode (for reliable ignition) and fuel-lean mode (for carbon removal). The control system alternates the torch ignitor operation between these two fuel-air ratio conditions, allowing carbon deposits to be removed during the fuel-lean phases while maintaining ignition reliability during fuel-rich phases.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system converts the harmful carbon deposit formation into a beneficial self-cleaning process. By intentionally operating in fuel-lean mode periodically, the carbon deposits that formed during fuel-rich operation are burned off as part of the normal operation cycle, transforming the harmful accumulation into a controlled cleaning mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Ease of manufacture

If conventional maintenance techniques are used for torch ignitors, then basic maintenance is performed, but excessive carbon growth cannot be prevented

Engineering Contradiction:
Improvemaintenance simplicityVSAvoidperformance consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The torch ignitor system performs its own maintenance by automatically switching to fuel-lean mode to remove carbon deposits during normal operation. This self-cleaning capability eliminates the need for external maintenance interventions and prevents performance deterioration without requiring additional maintenance complexity.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If carbon deposits are allowed to grow uncontrolled, then operational simplicity is maintained, but performance deteriorates and components erode

Engineering Contradiction:
Improveoperational simplicityVSAvoidignitor performance
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system dynamically adjusts the fuel-air ratio based on operational requirements. The control system monitors and switches between fuel-rich and fuel-lean modes, making the fuel-air mixture dynamic rather than static. This allows the system to optimize between ignition reliability and carbon removal without requiring complex manual intervention.

Inventive Principle:
Principle #15Dynamics

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 self-cleaning cycle effectively reduces and prevents carbon buildup on torch ignitor surfaces, ensuring continuous ignition performance and preventing downstream component erosion, allowing for extended operational periods and reduced maintenance needs.

Implementation Method 1

heating interior surfaces of the torch ignitor, wherein the fuel-lean flow reacts with carbon deposits on the interior surfaces to remove the carbon deposits

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

heating interior surfaces of the torch ignitor, wherein the fuel-lean flow reacts with carbon deposits on the interior surfaces to remove the carbon deposits

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP4141324B1Method of operating and cleaning a torch ignitor
Publication Date: 2024.06.26 COLLINS ENGINE NOZZLES INC
  • EP4141324B1 patent drawingFigure 1
  • EP4141324B1 patent drawingFigure 2

AI summary

A method of operating and cleaning a torch ignitor (101) for continuous ignition includes issuing a fuel-lean flow through a combustion chamber (104) of a torch ignitor. The method also includes heating interior surfaces of the torch ignitor (101), wherein the fuel-lean flow reacts with carbon deposits on the interior surfaces to remove the carbon deposits.