Mini Mixing Fuel Nozzle Assembly Combustion Stability
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Solution Overview
Problem
Gas turbine engines face challenges in achieving high-energy combustion while minimizing emissions and combustion instability at both full power and part power conditions, requiring an efficient fuel nozzle design that optimizes fuel-air mixing and combustion dynamics.
Innovation Solution
A mini mixing fuel nozzle assembly with a mixing sleeve and combustor design that includes multiple fuel injectors and a pressure atomizer, providing a separately controllable fuel-air mixing passage to enhance ignition, emissions control, and combustion stability, and featuring radially oriented air inlet ports to improve fuel atomization and combustion performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional fuel nozzle design is used, then the structure is simple, but combustion stability and emissions control are insufficient at part power conditions
Solution Approach 1:
The fuel nozzle is segmented into multiple independent functional components: a centerbody with fuel injectors, an outer sleeve with air inlet ports, and a mixing passage system. This segmentation allows each component to be optimized independently for its specific function while maintaining overall combustion stability across different power conditions.
Solution Approach 2:
The nozzle design incorporates dynamic flow control through the mixing passage that adapts to different operating conditions. The passage geometry and air-fuel mixing ratio can vary with power demand, enabling stable combustion at part power while maintaining simplicity of the overall nozzle structure.
2Power
If high-energy combustion is achieved, then power output increases, but emissions and combustion instability increase
Solution Approach 1:
Fuel and air are premixed in the mixing passage before entering the combustion chamber. This preliminary mixing ensures a controlled and homogeneous fuel-air mixture, enabling high-energy combustion while reducing emissions and preventing combustion instability through optimized air-fuel ratios.
Solution Approach 2:
The design changes the mixing parameters by controlling the air-fuel ratio in the mixing passage. By adjusting the proportion of air to fuel before combustion, the system achieves high-energy combustion with reduced emissions and improved stability across different operating conditions.
3Productivity
If fuel-air mixing is enhanced, then combustion efficiency improves, but device complexity increases
Solution Approach 1:
The mixing passage is integrated into the nozzle structure, combining the mixing function with the existing fuel injector and air supply system. This merging approach enhances combustion efficiency through improved fuel-air mixing while avoiding additional complex external mixing devices.
Solution Approach 2:
The mixing passage serves multiple functions: it mixes fuel and air, controls the air-fuel ratio, and stabilizes the combustion process. This multi-functionality improves combustion efficiency without requiring separate dedicated components for each function, thereby limiting complexity increase.
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
The design achieves high-energy combustion with reduced emissions and increased stability at various power conditions, preventing lean blow-out and improving overall gas turbine engine operability by controlling combustion dynamics and emissions across the combustion chamber.
Implementation Method 1
featuring radially oriented air inlet ports to improve fuel atomization and combustion performance
Implementation Method 2
providing a separately controllable fuel-air mixing passage to enhance ignition, emissions control, and combustion stability
Implementation Method 3
Aircraft and industrial gas turbine engines include a combustor in which fuel is burned to input energy to the engine cycle
Data Source
AI summary
The present disclosure is directed to a fuel nozzle for a gas turbine engine. The fuel nozzle includes a sleeve defining a plurality of radially oriented air inlet ports. The sleeve defines a sleeve outlet at the downstream end of the fuel nozzle and a longitudinally extended annular inner wall inward of the sleeve in the radial direction. The inner wall defines a fluid passage and an inner wall outlet, in which the inner wall outlet is disposed toward the downstream end of the inner wall. At least a portion of the plurality of radially oriented air inlet ports is outward of the inner wall along the radial direction. The fuel nozzle further includes a plurality of fuel injectors surrounding the sleeve, in which the sleeve and each of the fuel injectors are connected to an aft body at the downstream end and a forward body at the upstream end.