Gas Turbine Combustor Optical Detection for Fuel Flow Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing combustor monitoring and control systems for gas turbine engines lack improvements in efficiency and accuracy, particularly in monitoring combustion chamber conditions.

Innovation Solution

A combustion assembly for a gas turbine engine equipped with an optical detection system that includes a photodetector assembly, slit, view port, and monochromator to measure optical characteristics such as temperature distributions, combustion constituent distributions, and acoustic conditions, with a controller to adjust fuel flow based on these measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing combustor monitoring and control systems are used, then basic monitoring function is provided, but monitoring precision and control accuracy are insufficient

Engineering Contradiction:
Improvecombustion chamber condition monitoring precisionVSAvoidoptical detection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The optical detection system is segmented into distinct functional modules: a photodetector assembly for light detection, a monochromator for wavelength selection, a view port for optical access, and a controller for coordination. Each module performs a specific function, allowing the complex measurement task to be divided into manageable components that can be optimized independently while maintaining overall system precision.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If optical detection system is implemented, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveoptical characteristic measurement accuracyVSAvoidcombustion assembly structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The optical detection system is designed with multi-functionality to justify its complexity. The system simultaneously measures multiple optical characteristics including temperature distributions, combustion constituent distributions, and acoustic conditions within the combustion chamber. This universal measurement capability allows a single complex system to replace multiple simpler systems, optimizing the overall device architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The view port serves as an intermediary component that enables optical access from the detection system to the combustion chamber interior without compromising the chamber's structural integrity or thermal insulation. This mediator allows precise measurements while isolating the sensitive optical components from the harsh combustion environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If real-time optical measurements are performed, then control accuracy is improved, but energy consumption increases

Engineering Contradiction:
Improvefuel flow control accuracyVSAvoidoptical detection system energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The controller receives real-time optical measurement data from the photodetector assembly and uses this feedback to dynamically adjust fuel flow control. The system continuously monitors combustion chamber conditions and modifies fuel injection accordingly, creating a closed-loop control system that improves reliability while optimizing energy usage by only consuming detection energy when control adjustments are needed.

Inventive Principle:
Principle #23Feedback

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

Enhances the monitoring and control of combustion chamber conditions, allowing for precise adjustment of fuel flow to maintain optimal operating parameters, thereby improving engine performance and efficiency.

Implementation Method 1

a monochromator configured to direct an optical output

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

a photodetector assembly disposed at the fuel injector and outside of the combustion chamber

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP4417801B1Combustion assembly for a gas turbine engine with an optical detection system
Publication Date: 2025.09.17 RTX CORP
  • EP4417801B1 patent drawingFigure 1
  • EP4417801B1 patent drawingFigure 2
  • EP4417801B1 patent drawingFigure 2A

AI summary

A combustion assembly (68) for a gas turbine engine (20) includes a combustor (40), a monochromator (128), and a photodetector assembly (122). The combustor (40) forms a combustion chamber (98). The monochromator (128) is disposed outside the combustion chamber (98). The monochromator (128) is configured to receive an optical input (130) from the combustion chamber (98) and direct an optical output (132). The optical input (130) has a range of light wavelengths. The optical output (132) has a subset of the range of light wavelengths. The photodetector assembly (122) is disposed outside the combustion chamber (98). The photodetector assembly (122) is configured to receive the optical output (132) from the monochromator (128) and generate an output signal representative of one or more optical characteristics of the optical output (132).