Fuel Spray Nozzle Layout for Lower nvPM in RQL Combustors
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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.
Innovation Solution
The use of sustainable aviation fuel (SAF) in gas turbine engines with specific combustor configurations, including a rich burn, quick quench, lean burn (RQL) combustor and optimized fuel spray nozzle arrangements, to control and reduce nvPM emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional kerosene-based jet fuels are used in gas turbine engines, then engine performance is maintained, but non-volatile particulate matter (nvPM) emissions increase
Solution Approach 1:
The patent applies parameter changes by adjusting operating parameters (such as combustion temperature, pressure, and air-fuel ratio) when switching to sustainable aviation fuels with different chemical properties. This allows the engine to maintain optimal performance while reducing nvPM emissions associated with each specific fuel type
Solution Approach 2:
The patent implements dynamic adjustment of operating parameters based on the specific fuel being used. The system adapts in real-time to fuel composition variations, enabling the engine to handle multiple fuel types (traditional kerosene and sustainable aviation fuels) with optimized emission characteristics for each
2Object-generated harmful factors
If operating parameters are adjusted to reduce nvPM emissions, then environmental impact is reduced, but engine performance may be compromised
Solution Approach 1:
The patent optimizes combustion parameters (temperature, pressure, residence time) to achieve a balance where nvPM emissions are reduced while maintaining sufficient thrust. By carefully controlling the combustion process parameters, the system achieves lower emissions without significant power loss
Solution Approach 2:
The patent applies partial action by implementing emission reduction measures selectively during specific flight phases where nvPM reduction provides maximum benefit (such as idle and approach phases), while maintaining full performance capability during phases where power is critically needed
3Object-generated harmful factors
If fuel composition is changed to sustainable aviation fuel, then nvPM emissions are reduced, but combustion characteristics change requiring operational adjustments
Solution Approach 1:
The patent implements feedback control systems that monitor combustion parameters and fuel composition, automatically adjusting operating conditions to optimize both emission reduction and operational simplicity. The system learns from fuel composition variations and self-adjusts to maintain optimal performance
Solution Approach 2:
The patent applies preliminary action by pre-configuring operating parameter sets for different sustainable aviation fuel types. Before fuel switching occurs, the system pre-adjusts parameters to match the incoming fuel's characteristics, simplifying the transition process and maintaining ease of operation
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, minimizing soot deposits, contrail formation, and improving local air quality, while optimizing engine performance across different flight stages.
Implementation Method 1
a first idle-MTO nvPM emissions index ratio of the gas turbine engine is less than 0.8
Implementation Method 2
a rich burn, quick quench, lean burn (RQL) combustor
Data Source
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AI summary
A gas turbine engine (10) for an aircraft. The gas turbine engine comprising: a rich burn, quick quench, lean burn (RQL) combustor (16) having a number of fuel spray nozzles (403, 404) 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,maxTO 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; 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 (10) is less than 0.08. The gas turbine engine (10) is configured to provide fuel comprising a sustainable aviation fuel (SAF) to the fuel spray nozzles (403, 404). Also disclosed is a method of operating the gas turbine engine.