Gas Turbine Combustion Section Fuel Nozzle Positioning
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Solution Overview
Problem
The combustion section of gas turbine engines faces challenges in minimizing undesirable emissions such as NOx and CO, and combustor dynamics due to high operating temperatures, which current designs struggle to effectively mitigate.
Innovation Solution
The combustion section incorporates a specific configuration including an inner and outer liner, a dome with a heat shield, and a fuel nozzle positioned with defined separations and angles to optimize the combustion process, featuring a heat shield with a transition surface and thermal control features to manage thermal growth and maintain clearances, thereby reducing emissions and dynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fuel nozzle is positioned closer to the heat shield to improve combustion efficiency, then the combustion process becomes more efficient, but thermal growth and clearance maintenance become problematic
Solution Approach 1:
The patent applies parameter changes by specifying precise dimensional parameters for fuel nozzle positioning relative to the heat shield. The fuel nozzle is positioned at a specific distance and angle (e.g., 15-30 degrees from axial) to optimize combustion while maintaining adequate clearance. This quantitative parameter optimization resolves the contradiction between combustion efficiency and thermal clearance maintenance.
2Strength
If the combustion section is designed to withstand extremely high operating temperatures, then the structural integrity is maintained, but undesirable emissions such as NOx and CO increase
Solution Approach 1:
The patent applies local quality by creating specific local conditions within the combustion chamber through precise fuel nozzle positioning and heat shield configuration. The localized flow patterns and temperature distribution created by this geometry promote more complete combustion and reduce emissions in specific zones, while maintaining overall structural integrity against high temperatures.
3Stability of the object's composition
If the fuel nozzle is positioned to reduce combustor dynamics, then combustion stability improves, but combustion efficiency may be reduced
Solution Approach 1:
The patent applies dynamics by optimizing the fuel nozzle positioning to create balanced flow patterns that reduce combustor dynamics and pressure fluctuations. The specific angular and radial positioning (e.g., 15-30 degrees from axial direction) creates more stable combustion conditions while maintaining efficiency through proper fuel-air mixing.
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 results in a more efficient and stable combustion process, minimizing emissions and combustor dynamics while maintaining structural integrity under high temperatures, enhancing the overall performance of the gas turbine engine.
Implementation Method 1
a heat shield attached to the dome and including an aft surface... thermal control features to manage thermal growth and maintain clearances
Implementation Method 2
Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases
Data Source
AI summary
A combustion section for gas turbine engine includes an inner liner, an outer liner, and a dome attached to the inner liner and to the outer liner. A heat shield is attached to the dome, with the dome, the heat shield, or both define an opening. The combustion section also includes a fuel nozzle extending at least partially into the opening, the fuel nozzle defining a fuel nozzle axis and a radial direction relative to the fuel nozzle axis. The fuel nozzle defines an aft end, the aft end of the fuel nozzle positioned forward of the aft surface of the heat shield along the fuel nozzle axis such that the aft end of the fuel nozzle defines a minimum separation from the aft surface of the heat shield along the fuel nozzle axis of at least about 0.15 inches.