V-pattern Quench Jets for RQL Combustor NOx Reduction
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Solution Overview
Problem
The design of the quick quench section in RQL gas turbine engine combustors is a challenge in achieving low NOx emissions, as it requires precise mixing of fuel-rich gases with excess air to minimize high-temperature excursions and NOx formation.
Innovation Solution
The combustor features a V-pattern arrangement of air admission holes in both outer and inner liners, with staggered quench jets positioned between and aligned with fuel injectors to ensure thorough mixing and reduce residence times of combustion gases, thereby minimizing NOx formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional air admission hole arrangements are used in RQL combustors, then the combustor structure is simple, but NOx emissions are high due to insufficient mixing and prolonged residence times
Solution Approach 1:
The combustor liner is divided into multiple discrete liner regions, each with its own boundary lines and V-pattern air admission holes. This segmentation allows independent optimization of air mixing in each region while maintaining overall combustor functionality, directly addressing the complex quench zone geometry design challenge.
Solution Approach 2:
Each liner region is equipped with specifically configured V-pattern air admission holes that provide localized control over air-fuel mixing. The V-pattern geometry and positioning of holes create targeted quench jets in specific locations, enabling precise control of residence times and mixing characteristics in different combustor zones to reduce NOx emissions.
2Temperature
If air admission holes are arranged in conventional patterns, then manufacturing is easier, but mixing of fuel-rich gases with excess air is insufficient leading to high-temperature excursions
Solution Approach 1:
The air admission holes are arranged in asymmetric V-patterns within each liner region, with holes positioned at specific angles and distances from boundary lines. This asymmetric configuration creates non-uniform quench jet patterns that enhance mixing efficiency and prevent high-temperature excursions more effectively than symmetric arrangements.
Solution Approach 2:
The V-pattern air admission holes are positioned to deliver quench air ahead of the fuel-rich gases in the flow direction, creating preliminary mixing zones before the gases enter the lean burn section. This preliminary action ensures thorough mixing occurs before combustion, preventing high-temperature excursions and NOx formation.
3Object-generated harmful factors
If quench jets are not properly positioned, then device complexity is reduced, but residence times of combustion gases are prolonged increasing NOx formation
Solution Approach 1:
The air admission holes are positioned not only in the axial direction but also at specific circumferential locations defined by V-patterns and boundary lines. This multi-dimensional positioning creates staggered quench jets that penetrate the fuel-rich gases from multiple angles, significantly reducing residence times and thermal NOx formation while justifying the increased geometric complexity.
Solution Approach 2:
The V-pattern air admission holes act as intermediaries between the primary combustion zone and the lean burn section. By positioning these holes at specific locations within liner regions, they create intermediate mixing zones that gradually transition the fuel-rich gases to a lean state, preventing direct high-temperature combustion and reducing NOx formation.
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 effectively reduces NOx emissions by ensuring rapid and thorough mixing of fuel-rich gases to a lean state, reducing thermal NOx formation and minimizing pollutant emissions.
Implementation Method 1
the fuel-rich gases from the rich burn zone are rapidly mixed with excess air and passed to the lean burn zone
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An outer liner of a combustor of a gas turbine engine includes a plurality of liner regions arranged adjacent one another and separated by boundary lines; and a plurality of air admission holes formed in the liner regions. The air admission holes within each liner region form a V-pattern.