Combustor Nozzle Flow Distribution for Lower Idle 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 effectively.
Innovation Solution
The engine is configured with specific fuel spray nozzle arrangements and operates using sustainable aviation fuel (SAF), optimizing fuel distribution and combustion to minimize nvPM emissions through defined emissions index ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional kerosene-based jet fuel is used, then the engine operates with established performance characteristics, but nvPM emissions increase and environmental impact worsens
Solution Approach 1:
The patent applies parameter changes by adjusting operating parameters (fuel flow rate distribution among nozzles, combustion temperature, air-fuel ratio) when using SAF to optimize combustion characteristics and minimize nvPM emissions. The system monitors emissions and dynamically adjusts parameters to maintain optimal performance with alternative fuels.
Solution Approach 2:
The patent implements dynamics by enabling the engine control system to adaptively adjust operating parameters based on the detected fuel type. The system transitions from static, fuel-specific calibration to dynamic, real-time optimization, allowing the engine to automatically adapt to different fuel properties and maintain low emissions across fuel variations.
2Power
If fuel flow rate is increased to maintain power output, then engine performance is maintained, but nvPM emissions increase
Solution Approach 1:
The patent applies local quality by distributing fuel flow non-uniformly across different nozzle groups (annular, radial, axial) based on local combustion conditions. Each nozzle group receives optimized fuel flow rates tailored to its specific position and function, enabling complete combustion at lower overall fuel flow rates and reducing nvPM emissions while maintaining power output.
Solution Approach 2:
The patent segments the fuel injection system into multiple nozzle groups with independent flow control. This segmentation allows precise control of fuel distribution patterns, optimizing combustion efficiency at reduced fuel flow rates and minimizing particulate matter formation through improved fuel-air mixing in different combustion zones.
3Object-generated harmful factors
If combustion temperature is increased to reduce nvPM emissions, then emission levels decrease, but engine component stress and thermal loading increase
Solution Approach 1:
The patent applies parameter changes by optimizing the air-fuel ratio and combustion chamber pressure parameters to achieve complete combustion at moderate temperatures. By adjusting these parameters alongside fuel flow distribution, the system reduces nvPM emissions through improved combustion efficiency without requiring excessive temperature increases that would cause thermal stress.
4Productivity
If fuel spray nozzle configuration is optimized for specific fuel types, then combustion efficiency improves, but adaptability to different fuel types decreases
Solution Approach 1:
The patent implements dynamics by making the fuel spray nozzle system adaptable through active flow control. The nozzle configuration can dynamically adjust fuel flow rates to different nozzle groups based on detected fuel properties, maintaining optimized combustion efficiency across multiple fuel types including kerosene, SAF, and their blends without requiring physical reconfiguration.
Solution Approach 2:
The patent applies universality by designing a multi-functional fuel injection system that can operate optimally with multiple fuel types. The control system integrates fuel type detection with adaptive flow distribution algorithms, enabling a single nozzle configuration to serve multiple fuel types effectively by adjusting operational parameters rather than requiring fuel-specific hardware configurations.
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
Reduced nvPM emissions lead to decreased soot deposits, improved local air quality, and reduced contrail formation and radiative forcing, enhancing environmental impact during flight cycles.
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... configured to inject fuel into the combustion chamber
Data Source
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Figure 5
AI summary
A gas turbine engine (10) for an aircraft, comprising: a combustor (16), comprising a combustion chamber (120) and a plurality of fuel spray nozzles (124) configured to inject fuel into the combustion chamber (120), wherein the plurality of fuel spray nozzles (124) comprises a first subset (124A) of fuel spray nozzles (124) and a second subset (124B) of fuel spray nozzles (124), wherein the combustor (16) is operable in a condition in which each of the fuel spray nozzles of the first subset (124A) of fuel spray nozzles (124) is supplied with fuel at a greater fuel flow rate than each of the fuel spray nozzles of the second subset (124B) of fuel spray nozzles (124), wherein a ratio of the number of fuel spray nozzles (124) in the first subset (124A) of fuel spray nozzles (124) to the number of fuel spray nozzles (124) in the second subset (124B) of fuel spray nozzles (124) is in the range of 1:2 to 1:5. A first idle-MTO nvPM emissions index ratio is defined as: EIidleEImaxTO where: EIidle is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine (10) 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 (10) if operating at around 100% available thrust for the given operating conditions; the first idle-MTO nvPM emissions index ratio of the gas turbine engine (10) is less than 60. The gas turbine engine (10) is configured to provide fuel comprising a sustainable aviation fuel (SAF) to the plurality of fuel spray nozzles (124). Also disclosed is a method of operating the gas turbine engine (10).