RQL Combustor Nozzle Layout for Lower nvPM at Available Thrust
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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
The use of a rich burn, quick quench, lean burn (RQL) combustor with specific fuel spray nozzle configurations and the provision of sustainable aviation fuel (SAF) to optimize fuel distribution, ignition, and combustion, thereby reducing nvPM emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional kerosene-based jet fuel is used in gas turbine engines, then the engine operates with established performance characteristics, but non-volatile particulate matter (nvPM) emissions increase
Solution Approach 1:
The patent applies parameter changes by modifying combustion parameters (rich burn, quick quench, lean burn cycles) and fuel injection parameters (spray nozzle configurations, fuel-air ratio) to reduce nvPM emissions when using sustainable aviation fuels. This resolves the contradiction by adjusting operational parameters to accommodate different fuel types while maintaining low emissions.
Solution Approach 2:
The RQL combustor implements dynamic combustion control by cycling between rich burn, quick quench, and lean burn modes. This dynamic operation allows the engine to adapt to different fuel properties (including SAF) while maintaining optimized emission characteristics, thus resolving the contradiction between fuel flexibility and emission control.
2Productivity
If the number of fuel spray nozzles is increased to improve fuel distribution, then combustion efficiency improves, but device complexity increases
Solution Approach 1:
The patent applies local quality by optimizing fuel spray nozzle distribution and configuration within the combustor to achieve uniform fuel-air mixing. Rather than simply increasing nozzle数量, the design focuses on strategic placement and local fuel distribution characteristics to maximize combustion efficiency while controlling system complexity.
3Object-generated harmful factors
If nvPM emissions are reduced through optimized combustion, then soot deposits and contrail formation decrease, but fuel efficiency may be compromised
Solution Approach 1:
The RQL combustor maintains continuous optimized combustion through the cycling process, ensuring complete fuel burnout and minimizing soot formation. The quick quench phase rapidly cools the combustion products to freeze out particulate matter before they can form soot, while the lean burn phase ensures efficient fuel consumption. This continuous optimized action resolves the contradiction by maintaining both low emissions and high fuel efficiency.
Solution Approach 2:
The patent utilizes phase transitions in the RQL process, particularly the quick quench phase where rapid cooling causes condensation of combustion products. This phase transition effectively removes nvPM from the exhaust stream while maintaining combustion efficiency, resolving the contradiction between emission reduction and fuel efficiency.
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 configuration leads to reduced nvPM emissions, minimizing soot deposits, contrail formation, and improving local air quality, particularly at idle and cruise conditions, while optimizing fuel efficiency and environmental impact.
Implementation Method 1
a rich burn, quick quench, lean burn (RQL) combustor having a number of fuel spray nozzles in the range of 14-22
Data Source
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AI summary
A gas turbine engine (10) for an aircraft. The gas turbine engine (10) comprising: a rich burn, quick quench, lean burn (RQL) combustor (16) having a number of fuel spray nozzles (403, 404) in the range of 14-22 or a number of fuel spray nozzles per unit engine core size in the range 2 to 6. An MTO nvPM emissions index ratio is defined as: EImaxTO,SAFEImaxTO,FF where: EImaxTO,SAF is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine (10) when operating at around 100% available thrust for given operating conditions if a fuel provided to the fuel spray nozzles (403, 404) comprises a sustainable aviation fuel (SAF); and EImaxTO<FF is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine (10) when operating at around 100% available thrust for the given operating conditions if a fuel provided to the fuel spray nozzles (403, 404) is a fossil-based hydrocarbon fuel. The MTO nvPM emissions index ratio of the gas turbine engine (10) is less than 1. The gas turbine engine (10) is configured to provide fuel comprising a SAF to the fuel spray nozzles (403, 404). Also disclosed is a method of operating a gas turbine engine.