Combustor Nozzle Flow Split for Lower Gas Turbine nvPM Emissions
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Solution Overview
Problem
Gas turbine engines emit varying levels of non-volatile particulate matter (nvPM) depending on the fuel type and operating parameters, necessitating adjustments in operating methods to reduce emissions effectively.
Innovation Solution
The use of sustainable aviation fuel (SAF) and a combustor design with specific fuel spray nozzle configurations to control fuel flow rates, optimizing the ratio of fuel spray nozzles and adjusting operational settings to minimize 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 can operate with established fuel infrastructure, but non-volatile particulate matter emissions increase
Solution Approach 1:
The patent changes the chemical composition parameter 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 operability, demonstrating how modifying fuel properties can resolve the contradiction between emission reduction and fuel infrastructure compatibility.
Solution Approach 2:
The fuel spray nozzles are divided into multiple subsets (first subset, second subset, third subset) that can be independently controlled. This segmentation allows different fuel types to be delivered to different zones within the combustor, enabling optimized combustion for SAF while maintaining compatibility with traditional fuel infrastructure through selective nozzle operation.
2Object-generated harmful factors
If fuel spray nozzles are segmented into multiple subsets with different fuel flow rates, then nvPM emissions are reduced through optimized combustion, but the device complexity increases
Solution Approach 1:
The fuel spray nozzle system is segmented into multiple subsets (first subset with higher fuel flow rate, second subset with lower fuel flow rate, and third subset) that can be independently controlled. This segmentation enables optimized fuel distribution for SAF combustion, reducing nvPM emissions through improved mixing and combustion efficiency while maintaining manageable system complexity through modular nozzle design.
Solution Approach 2:
Different subsets of fuel spray nozzles are assigned different fuel flow rates based on their location and function within the combustor. The first subset receives higher fuel flow rates for primary combustion zones, while the second subset receives lower flow rates for secondary zones. This local quality differentiation optimizes combustion characteristics for SAF, reducing nvPM emissions without requiring uniform modification across the entire nozzle system.
3Object-generated harmful factors
If higher fuel flow rates are supplied to certain fuel spray nozzles, then combustion efficiency is improved and nvPM emissions are reduced, but fuel consumption increases
Solution Approach 1:
Higher fuel flow rates are supplied selectively to the first subset of fuel spray nozzles located in primary combustion zones where SAF requires enhanced atomization and mixing for complete combustion. The second subset receives lower fuel flow rates in secondary zones where less fuel is needed. This local differentiation improves combustion efficiency and reduces nvPM emissions by ensuring adequate fuel supply where needed while avoiding excess fuel consumption in zones where complete combustion is already achieved.
Solution Approach 2:
The fuel flow rate parameter is varied across different nozzle subsets based on combustion zone requirements and SAF properties. By optimizing the fuel flow rate distribution rather than uniformly increasing or decreasing it across all nozzles, the system achieves reduced nvPM emissions through improved combustion completeness while minimizing overall fuel consumption through precise local control.
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 nvPM emissions, leading to decreased soot deposits, improved local air quality, and reduced contrail formation, with targeted emission reductions at specific 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 and a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber
Data Source
AI summary
A gas turbine engine has a first subset of fuel spray nozzles and a second subset of fuel spray nozzles. A combustor is operable with the first subset of fuel spray nozzles supplied with fuel at a greater flow rate than each of the second subset of fuel spray nozzles. A ratio of the first subset of fuel spray nozzles to the second subset of fuel spray nozzles is 1:2 to 1:5. A first idle-MTO nvPM emissions index ratio is:EIidleEImaxTO,where: EIidle is the nvPM emissions index in mg/kg operating at around 7% available thrust; EImaxTO is the nvPM emissions index in mg/kg of the gas turbine engine operating at around 100% available thrust; and the first idle-MTO nvPM emissions index ratio of the gas turbine engine is less than 60. A sustainable aviation fuel (SAF) can be provided to the fuel spray nozzles.