Combustion Liner Dilution Geometry for Low-NOx Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current combustion liners in gas turbine engines face challenges in achieving efficient mixing and cooling of combustion products, leading to high temperature regions and increased NOx emissions due to either low jet penetration or high turbulence in discrete or annular dilution configurations.
Innovation Solution
A combustor liner design that integrates discrete dilution holes and annular slots through a concatenated geometry, combining first and second dilution air flows to form an integrated dilution air flow, enhancing jet penetration and mixing within the core primary combustion zone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If discrete dilution holes are used, then jet penetration is improved, but turbulence increases leading to high NOx emissions
Solution Approach 1:
The patent combines discrete dilution holes and annular slots into a hybrid configuration where the annular slot provides a continuous dilution flow that merges with the discrete jet flows. This merging approach allows the discrete holes to provide jet penetration while the annular slot suppresses excessive turbulence and NOx formation through its continuous, stabilizing flow pattern.
Solution Approach 2:
The dilution system uses a composite geometry combining two different flow structures (discrete holes and annular slots) to achieve properties that neither structure alone can provide. The discrete holes contribute high momentum for penetration while the annular slot contributes flow stability and turbulence control, creating a composite dilution effect that reduces NOx emissions.
2Object-generated harmful factors
If annular slots are used, then turbulence is reduced, but jet penetration decreases leading to poor mixing
Solution Approach 1:
The patent merges the flow from annular slots with discrete dilution holes to create a hybrid system. The annular slot provides a base flow that reduces turbulence and NOx emissions, while the discrete holes superimposed on this flow provide the necessary jet penetration and mixing capability that pure annular slots lack.
3Temperature
If more dilution air flow is provided, then temperature reduction is improved, but mixing efficiency decreases due to high turbulence
Solution Approach 1:
The hybrid dilution configuration creates a composite flow structure where the annular slot provides a stable, low-turbulence base flow that allows for higher overall dilution air flow rates. The discrete holes provide localized high-momentum injection that enhances mixing without the excessive turbulence that would result from simply increasing discrete hole flow alone. This composite approach enables greater temperature reduction while maintaining mixing uniformity.
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 integrated dilution air flow reduces temperature and NOx emissions, achieving uniform temperature distribution and compliance with regulatory guidelines by improving mixing and cooling efficiency.
Implementation Method 1
The dilution air flow mixes with primary zone products within the combustor
Implementation Method 2
The integrated dilution air flow reduces temperature and NOx emissions, achieving uniform temperature distribution
Data Source
AI summary
A liner for a combustor in a gas turbine engine and a related method. The liner includes a liner body having a cold side and a hot side. The liner includes a dilution array having a plurality of dilution passages, each dilution passage of the plurality of dilution passages having a concatenated geometry repeating in a predetermined pattern and extending circumferentially around the liner body. The dilution passage integrates a first dilution air flow flowing through the dilution passage from the cold side to the hot side and a second dilution air flow flowing through the dilution passage from the cold side to the hot side into an integrated dilution air flow and injects the integrated dilution air flow into a core primary combustion zone of the combustor to attain a predetermined combustion state of the combustor. The dilution array is repeated along an axial length of the liner body.