RQL Fuel Spray Nozzle Layout for Lower Aircraft nvPM Emissions
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Solution Overview
Problem
Gas turbine engines emit varying amounts of non-volatile particulate matter (nvPM) depending on the type and properties of the fuel used, necessitating adjustments in operating methods to reduce emissions and environmental impact.
Innovation Solution
The use of a rich burn, quick quench, lean burn (RQL) combustor with a specific number of fuel spray nozzles, combined with the use of sustainable aviation fuel (SAF), to optimize the idle-MTO, second idle-MTO, fuel-flow, thrust, lean cruise-MTO, and rich cruise-MTO nvPM emissions index ratios, thereby reducing nvPM emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional kerosene-based jet fuels are used, then engine operation is straightforward and well-established, but non-volatile particulate matter (nvPM) emissions are higher and environmental impact is greater
Solution Approach 1:
The patent applies parameter changes by adjusting combustor operating parameters (rich burn, quick quench, lean burn zones) and fuel injection characteristics to optimize nvPM emissions when using alternative fuels like sustainable aviation fuel (SAF), thereby resolving the contradiction between reducing harmful emissions and maintaining fuel adaptability
Solution Approach 2:
The system dynamically adjusts fuel spray nozzle configurations and combustor operating conditions based on the specific fuel type being used, enabling the engine to adapt to different fuel properties while minimizing nvPM emissions across various operating conditions
2Productivity
If fuel spray nozzles are increased in number, then fuel distribution is improved and combustion efficiency increases, but device complexity increases
Solution Approach 1:
The combustor is segmented into multiple functional zones (rich burn zone, quick quench zone, lean burn zone) with strategically positioned fuel spray nozzles, achieving improved fuel distribution and combustion efficiency while managing structural complexity through systematic segmentation
Solution Approach 2:
Different regions of the combustor are designed with different nozzle configurations and combustion characteristics tailored to local requirements, optimizing fuel distribution and combustion efficiency in each zone while maintaining overall system manageability
3Object-generated harmful factors
If nvPM emissions are reduced, then environmental impact and soot deposits are decreased, but engine performance and thrust may be affected
Solution Approach 1:
The combustor maintains continuous combustion across all three zones (rich, quick quench, lean burn) to ensure uninterrupted energy release and thrust production while minimizing nvPM emissions through optimized combustion chemistry in each zone
Solution Approach 2:
Operating parameters such as fuel-to-air ratio, temperature, and pressure are dynamically adjusted across different combustor zones to optimize the balance between thrust generation and nvPM formation, allowing the engine to maintain power output while reducing emissions
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 soot deposits within the engine, improved local air quality, and decreased contrail formation and dispersal time, particularly at idle and cruise conditions, enhancing environmental performance.
Implementation Method 1
fuel spray nozzles
Implementation Method 2
rich burn, quick quench, lean burn (RQL) combustor
Implementation Method 3
combustion
Data Source
AI summary
A gas turbine engine for an aircraft. The gas turbine engine comprising: a rich burn, quick quench, lean burn (RQL) combustor having a number of fuel spray nozzles in the range 14-22 or a number of fuel spray nozzles per unit engine core size in the range 2 to 6. A fuel-flow nvPM emissions index ratio is defined as:EIidle×Wf,idleEImaxTO×Wf,maxTOwhere: EIidle is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine if operating at around 7% available thrust for given operating conditions; and EImaxTO is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine if operating at around 100% available thrust for the given operating conditions; Wf,idle is the rate of fuel flow to the fuel spray nozzles in kg/s at around 7% available thrust for the given operating conditions; and Wf,maxTO is the rate of fuel flow to the fuel spray nozzles in kg/s at around 100% available thrust for the given operating conditions. The fuel-flow nvPM emissions index ratio of the gas turbine engine is less than 0.08. The gas turbine engine is configured to provide fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles. Also disclosed is a method of operating the gas turbine engine.