Aircraft Fuel Nozzle Split Flow for Lower 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.
Innovation Solution
The gas turbine engine is configured with specific fuel spray nozzle arrangements and operates using sustainable aviation fuel (SAF) to optimize fuel distribution and combustion, thereby reducing nvPM emissions through controlled fuel flow rates and ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional kerosene-based jet fuels are used in gas turbine engines, then the engines can operate with established fuel systems, but the engines produce higher amounts of non-volatile particulate matter (nvPM) emissions
Solution Approach 1:
The patent applies parameter changes by adjusting operating parameters (such as fuel flow rates, air-fuel ratios, and combustion temperatures) when using sustainable aviation fuel (SAF) compared to traditional kerosene. This allows the engine to optimize combustion characteristics and reduce nvPM emissions while adapting to the different chemical properties of SAF, thereby resolving the contradiction between reducing harmful emissions and maintaining fuel flexibility
Solution Approach 2:
The patent implements dynamic adjustment of engine operating parameters based on the type of fuel being used. The engine control system dynamically modifies combustion chamber conditions, fuel injection rates, and airflow parameters to accommodate different fuel types (kerosene vs. SAF), enabling the engine to maintain optimal performance and minimize nvPM emissions across different fuel scenarios
2Power
If fuel flow rates are increased to maintain power output, then the engine can deliver required thrust, but the nvPM emissions increase proportionally
Solution Approach 1:
The patent changes combustion parameters such as air-fuel ratio, combustion temperature, and residence time to decouple the direct proportionality between fuel flow rate and nvPM emissions. By optimizing these parameters, the engine can maintain required thrust output while operating at fuel flow rates that produce lower nvPM emissions per unit of energy delivered
Solution Approach 2:
The patent applies local quality by creating different combustion zones within the combustion chamber with varying oxygen concentrations, temperatures, and fuel-air mixing characteristics. This allows certain regions to promote complete combustion (reducing nvPM) while maintaining overall power output, thereby resolving the contradiction between thrust delivery and emission reduction
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 strength, and improving local air quality, particularly at idle and cruise conditions, while optimizing fuel efficiency and environmental impact.
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
Figure 1
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AI summary
A gas turbine engine (10) for an aircraft. The gas turbine engine (10) comprises: 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 1:3 to 1:6. A lean cruise nvPM emissions index ratio is defined as: EIcruiselean,SAFEIcruiselean,FF where: EIcruise(lean),SAF is defined as: EImaxTO,SAF+EIclimb,SAF2 EIcruise(lean),FF is defined as: EImaxTO,FF+EIclimb,FF2 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 plurality of fuel spray nozzles (124) comprises a sustainable aviation fuel; EIclimb,SAF is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine (10) when operating at around 85% available thrust for the given operating conditions if a fuel provided to the plurality of fuel spray nozzles (124) comprises a sustainable aviation fuel; 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 plurality of fuel spray nozzles (124) is a fossil-based hydrocarbon fuel; and EIclimb,FF is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine (10) when operating at around 85% available thrust for the given operating conditions if a fuel provided to the plurality of fuel spray nozzles (124) is a fossil-based hydrocarbon fuel. The lean cruise 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 sustainable aviation fuel (SAF) to the plurality of fuel spray nozzles (124).