Non-Round Combustor Cap Outlets for Emission Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gas turbine engine combustor designs face challenges in reducing exhaust emissions and extending equipment life due to limitations in fuel nozzle assembly design, which affects installation, maintenance, and emissions production.
Innovation Solution
A combustor cap with integrated nozzles featuring non-round outlets is introduced, which alters the flame characteristics by increasing the shear area and surface area for heat transfer, thereby reducing emissions and improving cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional round outlets are used in combustor nozzles, then the design is simple and easy to manufacture, but emissions are higher and flame length is longer
Solution Approach 1:
The patent applies asymmetry by changing the nozzle outlet from a conventional circular shape to a non-circular shape with multiple lobes. This asymmetric geometry increases the shear area and surface area for heat transfer, which reduces emissions (NOx and CO) while maintaining manufacturability through standard casting or machining processes.
Solution Approach 2:
The patent changes the geometric parameters of the nozzle outlet by introducing multiple lobes with specific angles and dimensions. This parameter change increases the surface area and shear area, optimizing flame characteristics and reducing emissions without significantly complicating the manufacturing process.
2Ease of operation
If conventional round outlets are used in combustor nozzles, then the manufacturing cost is lower, but flame length is longer and heat transfer efficiency is lower
Solution Approach 1:
The non-circular lobe-shaped outlet provides increased surface area for heat transfer compared to a circular outlet of equivalent flow area. This asymmetric geometry allows better thermal coupling with the surrounding combustion chamber, improving heat transfer efficiency while remaining manufacturable.
Solution Approach 2:
The patent transitions from a two-dimensional circular cross-section to a multi-lobed shape that utilizes additional geometric dimensions. This dimensional complexity increases the effective surface area and shear area, enhancing heat transfer and flame control capabilities.
3Reliability
If non-round outlets with larger surface area are used, then emissions are reduced and heat transfer is improved, but the nozzle design becomes more complex
Solution Approach 1:
The multi-lobed asymmetric outlet geometry increases the surface area for heat transfer and shear area for mixing, which improves combustion efficiency and reduces emissions. This extends equipment life by promoting more complete combustion and reducing thermal stresses, while the geometry remains relatively simple to manufacture.
Solution Approach 2:
The patent applies local quality by creating specific lobe regions with different orientations and dimensions within the nozzle outlet. Each lobe can be optimized for specific functions such as enhancing mixing in certain directions or improving heat transfer to specific areas, while the overall structure remains manufacturable.
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 combustor cap design shortens flame length, reduces emissions such as NOx and CO, lowers manufacturing costs, and extends equipment life by optimizing flame characteristics and heat transfer.
Implementation Method 1
increasing the shear area and surface area for heat transfer
Implementation Method 2
surface area for heat transfer
Implementation Method 3
mix air and fuel to form an air-fuel mixture
Implementation Method 4
combusts a mixture of fuel and air to generate hot combustion gases
Data Source
AI summary
A system includes a a combustor cap configured to be coupled to a plurality of mixing tubes of a multi-tube fuel nozzle, wherein each mixing tube of the plurality of mixing tubes is configured to mix air and fuel to form an air-fuel mixture. The combustor cap includes multiple nozzles integrated within the combustor cap. Each nozzle of the multiple nozzles is coupled to a respective mixing tube of the multiple mixing tubes. In addition, each nozzle of the multiple nozzles includes a first end and a second end. The first end is coupled to the respective mixing tube of the multiple mixing tubes. The second end defines a non-round outlet for the air-fuel mixture. Each nozzle of the multiple nozzles includes an inner surface having first and second portions, the first portion radially diverges along an axial direction from the first end to the second end, and the second portion radially converges along the axial direction from the first end to the second end.