Staggered Quench Jets for NOx Reduction in RQL Combustors
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Solution Overview
Problem
Current gas turbine engine combustors face challenges in reducing NOx emissions, particularly in the design of the quick quench section of rich burn, quick quench, lean burn (RQL) combustors, where effective mixing of fuel-rich gases with excess air is crucial to minimize high-temperature excursions and NOx formation.
Innovation Solution
The combustor design incorporates a V-shaped arrangement of staggered air admission holes in both inner and outer liners, with major and minor holes positioned to create quench jets that rapidly mix combustion products from a rich to a lean state, reducing residence times and NOx formation by optimizing the quench air distribution and penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional air admission hole arrangements are used in RQL combustors, then the structure is simple, but NOx emissions cannot be effectively reduced due to insufficient mixing of fuel-rich gases with excess air
Solution Approach 1:
The air admission system is segmented into multiple groups of holes arranged in specific patterns (V-shaped, staggered, alternating sizes) on both inner and outer liners, with each group serving specific quench functions at different locations to achieve thorough mixing and NOx reduction
Solution Approach 2:
Different regions of the combustor liner are equipped with air admission holes of different sizes and arrangements tailored to local mixing requirements, with major and minor holes positioned to create targeted quench jets in specific zones
2Productivity
If air admission holes are uniformly distributed, then the structure is simple, but quench air distribution and penetration are insufficient to achieve rapid mixing
Solution Approach 1:
The air admission holes are arranged in asymmetric V-shaped patterns with alternating major and minor hole sizes, creating non-uniform quench jet distributions that enhance mixing efficiency compared to uniform arrangements
Solution Approach 2:
The air admission system utilizes both inner and outer liner surfaces with staggered hole patterns, adding spatial dimensions to quench air injection and creating multi-directional mixing flows
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 thorough mixing and proper distribution of quench air, preventing excessive NOx generation and improving combustion efficiency in the quench zone.
Implementation Method 1
rapidly mixed with excess air
Implementation Method 2
quench jets that rapidly mix combustion products
Implementation Method 3
V-shaped arrangement of staggered air admission holes... optimizing the quench air distribution and penetration
Data Source
Figure 1
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AI summary
A combustor for a turbine engine includes an outer liner having a first group of air admission holes and defining a plurality of outer liner regions. The combustor further includes an inner liner circumscribed by the outer liner and forming a combustion chamber therebetween, the inner liner having a second group of air admission holes and defming a plurality of inner liner regions. The combustor further includes a plurality of fuel injectors extending into the combustion chamber and configured to deliver an air-fuel mixture to the combustion chamber, each of the plurality of fuel injectors being associated with one of the outer liner regions and one of the inner liner regions. The first group within a respective outer liner region includes air admission holes that circumferentially alternate between approximately a first size and approximately a second size, the first size being different than the second size.