Non-Circular Combustor Liner Inserts for RQL NOx Reduction
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Solution Overview
Problem
Modern gas turbine combustors face challenges in achieving low NOx emissions and high durability while operating at high temperatures, particularly in the design and implementation of the quench zone geometry in rich burn, quick quench, lean burn (RQL) combustors.
Innovation Solution
The use of non-circular shaped inserts within air admission holes in combustor liners, featuring a tubular body portion and a shoulder to guide pressurized air jets into the combustion chamber, with anti-rotation features to prevent insert rotation and secure retention without welding, allowing for precise control of air-fuel mixing and reduced NOx formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional circular air admission holes are used in combustor liners, then manufacturing is simpler, but precise control of air-fuel mixing and reduction of NOx emissions cannot be achieved
Solution Approach 1:
The patent applies asymmetry by using non-circular air admission holes (such as rectangular, oval, or irregular shapes) instead of traditional circular holes. This asymmetric geometry creates specific flow patterns that enhance mixing between air and fuel, control residence time in the combustion zone, and reduce peak temperatures, thereby lowering NOx emissions while maintaining manufacturability through standard machining processes.
2Manufacturing precision
If inserts are used in air admission holes to control flow, then air-fuel mixing precision improves, but insert rotation and secure retention become problems
Solution Approach 1:
The insert includes asymmetric anti-rotation features such as keys, splines, or non-circular cross-sections that mate with corresponding features in the non-circular air admission hole. This asymmetric configuration prevents the insert from rotating during operation, ensuring stable and reliable air-fuel mixing control while being installable without welding or bonding.
3Object-generated harmful factors
If RQL combustor geometry is optimized for low NOx, then emissions reduce, but operability and durability at high temperatures may be compromised
Solution Approach 1:
The patent applies local quality by implementing non-circular air admission holes and inserts with specific geometries in critical zones of the combustor where air-fuel mixing occurs. These localized geometric modifications create controlled turbulence and mixing patterns that reduce peak temperatures and NOx formation, while the rest of the combustor maintains its high-temperature design for durability and operability.
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 enhances combustion efficiency, reduces NOx emissions, and increases the durability of the combustor by preventing insert rotation and ensuring secure retention, thereby improving the operability and thermal management of the RQL combustor.
Implementation Method 1
an insert positioned within the air admission hole to guide the first jet through the air admission hole and into the combustion chamber
Implementation Method 2
a combustor for burning fuel in the presence of the pressurized air
Implementation Method 3
a turbine for extracting energy from the resultant combustion gases
Data Source
AI summary
A combustor for a turbine engine is provided. The combustor includes a first liner and a second liner forming a combustion chamber with the first liner, the combustion chamber configured to receive an air-fuel mixture for combustion therein. The first liner defining an air admission hole for directing a first jet of pressurized air into the combustion chamber, and the air admission hole may have a non-circular shape. The combustor further includes an insert positioned within the air admission hole to guide the first jet through the air admission hole and into the combustion chamber.