RQL Aircraft Combustor Nozzle Layout for Lower nvPM Emissions
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Solution Overview
Problem
Gas turbine engines emit varying amounts of non-volatile particulate matter (nvPM) depending on the fuel type and operating parameters, necessitating adjustments in operating methods to reduce emissions.
Innovation Solution
Implementing a gas turbine engine with a rich burn, quick quench, lean burn (RQL) combustor and optimizing fuel distribution using sustainable aviation fuel (SAF) to achieve specific nvPM emissions index ratios, such as idle-MTO, second idle-MTO, fuel-flow, and thrust nvPM emissions index ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional kerosene-based jet fuels are used in gas turbine engines, then engine performance is maintained, but non-volatile particulate matter (nvPM) emissions increase
Solution Approach 1:
The patent changes the fuel parameter from traditional kerosene-based jet fuel to sustainable aviation fuel (SAF), which has different chemical composition and combustion characteristics. This parameter change reduces nvPM emissions while maintaining engine performance, directly addressing the contradiction between harmful emissions and fuel adaptability
Solution Approach 2:
The patent introduces SAF as an intermediary fuel option between traditional kerosene and alternative fuels. SAF serves as a mediator that enables the transition to lower-emission fuels while maintaining compatibility with existing gas turbine engine infrastructure, thus reducing nvPM emissions without sacrificing fuel flexibility
2Manufacturing precision
If fuel spray nozzles are increased in number or density, then fuel distribution is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by varying the nozzle configuration in different regions of the combustor. Instead of uniform distribution, the nozzle arrangement is optimized for local combustion requirements, improving fuel distribution uniformity in critical areas while avoiding unnecessary complexity throughout the entire combustor structure
Solution Approach 2:
The patent employs dynamic fuel injection control where the fuel spray nozzles operate with variable parameters (pressure, flow rate, atomization patterns) that adapt to different combustion stages and zones. This dynamic operation achieves superior fuel distribution without requiring a proportional increase in static nozzle quantity, thus managing device complexity
3Object-generated harmful factors
If rich burn, quick quench, lean burn (RQL) combustor configuration is used, then nvPM emissions are reduced, but combustor design complexity increases
Solution Approach 1:
The patent segments the combustor into distinct functional zones: rich burn region, quick quench region, and lean burn region. Each zone is optimized for specific combustion chemistry that reduces nvPM formation. This segmentation achieves emission reduction while managing complexity through modular zone design rather than a monolithic complex structure
Solution Approach 2:
The RQL combustor configuration creates periodic combustion cycles within the combustor volume, where fuel-air mixtures undergo alternating rich and lean combustion phases. This periodic action promotes complete combustion and reduces soot formation, achieving nvPM reduction through temporal-spatial combustion cycling rather than requiring overly complex static结构设计
4Object-generated harmful factors
If sustainable aviation fuel (SAF) is used, then environmental impact is reduced, but fuel distribution control becomes more challenging
Solution Approach 1:
The patent implements feedback control in the fuel injection system that monitors combustion parameters (pressure, temperature, oxygen concentration) and adjusts fuel spray characteristics accordingly. This feedback mechanism compensates for the different combustion properties of SAF, maintaining optimal fuel distribution and combustion efficiency while reducing environmental impact
Solution Approach 2:
The patent adjusts fuel injection parameters (pressure, flow rate, atomization patterns) specifically optimized for SAF combustion characteristics. These parameter changes enable effective fuel distribution control despite the different chemical properties of SAF compared to traditional kerosene, thus maintaining ease of operation while achieving environmental benefits
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
Reduces non-volatile particulate matter emissions, minimizing soot deposits, contrail formation, and improving local air quality, while optimizing engine performance and reducing environmental impact.
Implementation Method 1
a rich burn, quick quench, lean burn (RQL) combustor having a number of fuel spray nozzles
Implementation Method 2
rich burn, quick quench, lean burn (RQL) combustor
Implementation Method 3
reduced nvPM in the exhaust of a gas turbine engine
Data Source
AI summary
A gas turbine engine for an aircraft includes a rich burn, quick quench, lean burn combustor having 14-22 fuel spray nozzles or 2-6 fuel spray nozzles per unit engine core size. A thrust nvPM emissions index ratio isEImaxTO/FmaxTOEIidle/Fidle.EIidle is the nvPM emissions index in mg/kg of the gas turbine engine operating at around 7% available thrust for given operating conditions. EImaxTO is the nvPM emissions index in mg/kg of the gas turbine engine operating at around 100% available thrust for the given operating conditions. FmaxTO is the thrust of the gas turbine engine at around 100% available thrust in kN. Fidle is the thrust of the gas turbine engine at around 7% available thrust in kN. The thrust nvPM emissions index ratio is greater than 0.09. The gas turbine engine is configured to provide fuel comprising a sustainable aviation fuel to the fuel spray nozzles.