Combustor Nozzle Flow Staging for Lower nvPM in Aircraft Engines
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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 gas turbine engine is configured with a combustor featuring a plurality of fuel spray nozzles, including a first and second subset, where the first subset receives a higher fuel flow rate, and operates using sustainable aviation fuel (SAF) to achieve specific nvPM emissions index ratios, such as idle-MTO, second idle-MTO, fuel-flow, thrust, and lean/rich cruise-MTO ratios, all below certain thresholds.
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 changes the chemical composition parameters of the fuel by using sustainable aviation fuel (SAF) instead of traditional kerosene-based jet fuel. This parameter change directly reduces nvPM emissions while maintaining engine performance, as SAF has different combustion characteristics that produce fewer particulate matter emissions.
Solution Approach 2:
The fuel spray nozzles are segmented into different subsets (first subset and second subset) with different fuel flow rates. This segmentation allows optimized fuel distribution patterns that work effectively with SAF, enabling the engine to achieve low nvPM emissions across various operating conditions while maintaining adaptability to different fuel types.
2Power
If fuel flow rates are increased to maintain engine performance, then power output is maintained, but nvPM emissions increase
Solution Approach 1:
Different subsets of fuel spray nozzles are assigned different local fuel flow rates based on their position and function within the combustor. The first subset receives fuel at a different flow rate than the second subset, creating localized optimization that maintains overall engine power while reducing nvPM emissions through improved fuel-air mixing and combustion efficiency.
3Object-generated harmful factors
If operating parameters are adjusted to reduce nvPM emissions, then environmental impact decreases, but engine performance may be compromised
Solution Approach 1:
The fuel spray nozzle system is designed with dynamic control capabilities, allowing fuel flow rates to different nozzle subsets to be adjusted based on operating conditions. This dynamic adjustment enables the engine to maintain optimal performance across different flight stages (idle, climb, cruise, descent) while consistently achieving low nvPM emissions through adaptive fuel distribution.
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 reduces nvPM emissions, minimizing soot deposits, contrail formation, and environmental impact, improving local air quality, and optimizing engine performance across different flight stages.
Implementation Method 1
a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber
Implementation Method 2
a combustor, comprising a combustion chamber
Data Source
AI summary
A gas turbine engine for aircraft includes a combustor with a combustion chamber and fuel spray nozzles to inject fuel into the combustion chamber. The fuel spray nozzles include a first subset and a second subset of nozzles. Each of the first subset is supplied with fuel at a greater rate than each of the second subset. A ratio of the first subset to the second subset is 1:2 to 1:5. A MTO nvPM emissions index ratio isEImaxTO,SAFEImaxTO,FF.EImaxTO,SAF is nvPM emissions index in mg/kg of the engine when operating at around 100% available thrust if fuel provided to the fuel spray nozzles includes sustainable aviation fuel. EImaxTO,FF IS nvPM emissions index in mg/kg of the engine when operating at around 100% available thrust if fuel provided to the fuel spray nozzles is fossil-based hydrocarbon fuel. The MTO nvPM emissions index ratio is less than 1.