Combustor Liner Fuel Injector Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional late lean injection systems in combustion turbine engines are complex, costly, and inefficient, with high risks of fuel leakage and poor fuel/air mixing, leading to suboptimal combustion and increased NOx and CO emissions.
Innovation Solution
A fuel injection system with a plenum and tube configuration that directs compressed air through a flow annulus, providing a longer mixing path and efficient air usage, while restricting back-flow to prevent flame-holding, using fuel outlets positioned within the tube to enhance fuel/air mixing and combustion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional late lean injection assemblies are used, then fuel injection functionality is provided, but system complexity and manufacturing cost increase significantly
Solution Approach 1:
The patent combines multiple functions into a single integrated fuel injector assembly. The body portion integrates the fuel injection nozzle, air mixing passages, and cooling channels into one component, eliminating the need for separate tubing assemblies and multiple interface connections. This merging reduces both manufacturing cost and system complexity while maintaining the required fuel injection and air mixing functions.
Solution Approach 2:
The fuel injector body serves multiple functions simultaneously: it acts as a fuel injection nozzle, an air mixing chamber, a cooling passage conduit, and a structural support element. The body portion receives compressed air from the flow annulus and mixes it with fuel before injection, while also providing thermal management through integrated cooling channels. This multi-functionality reduces the number of separate components needed.
2Reliability
If conventional late lean injection systems are used, then fuel injection is achieved, but fuel leakage risk into compressor discharge casing increases
Solution Approach 1:
The patent extracts the fuel injection functionality from complex external tubing systems and integrates it directly into the combustor liner through a simplified body portion. The fuel injection nozzle is positioned within the liner, and the air mixing passages are formed directly in the body, eliminating numerous external connections and interfaces that could potentially leak fuel into the compressor discharge casing.
Solution Approach 2:
The body portion acts as an intermediary structure that safely channels fuel and air mixing within the combustor environment. The integrated design ensures that fuel-air mixture preparation occurs within the controlled environment of the combustor liner, with proper sealing and containment, preventing leakage into the compressor discharge casing while simplifying the overall assembly.
3Manufacturing precision
If conventional late lean injectors are used, then fuel injection is provided, but fuel/air mixing performance deteriorates
Solution Approach 1:
The patent segments the air flow into distinct pathways within the body portion, with separate mixing passages that guide compressed air from the flow annulus to mix with fuel in controlled zones. The body includes specific air mixing passages that create proper turbulence and mixing patterns, ensuring high-quality fuel/air mixture while the integrated design keeps manufacturing costs reasonable compared to conventional multi-component systems.
4Use of energy by moving object
If air from flow annulus is not utilized, then simple air supply is maintained, but air usage efficiency decreases
Solution Approach 1:
The fuel injector assembly utilizes compressed air that is already present in the flow annulus, allowing this air to serve dual purposes: cooling the combustor liner and providing the oxidizer for fuel combustion. The body portion is configured to receive air directly from the flow annulus through integrated passages, eliminating the need for separate air supply lines and improving overall air usage efficiency without significant additional complexity.
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 system reduces manufacturing and assembly costs, improves fuel/air mixing, and effectively limits NOx emissions by utilizing air already within the flow annulus for cooling, resulting in better combustion characteristics and operational benefits.
Implementation Method 1
compressed air is directed through said flow annulus to the forward end of the combustor
Implementation Method 2
a tube comprising a first end positioned within the first port and a second end positioned within the second port
Implementation Method 3
providing a longer mixing path and efficient air usage
Implementation Method 4
directs compressed air through a flow annulus, providing a longer mixing path
Implementation Method 5
restricting the back-flow of fluid within the passage that traverses the flow annulus within the combustor so to limit the occurrence of flame-holding
Implementation Method 6
fuel outlets characterized in that the fuel outlets are disposed within the first passage
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An assembly for use in a fuel injection system within a combustor of a combustion turbine engine is described. The assembly may include: a first port (42) formed through an outer radial wall (26) of the combustor and a second port (43) formed through an inner radial wall (24). A plenum (44) may be formed about the first port. A tube (45) may be formed that has a first end positioned within the first port and a second end positioned within the second port. At the first end, the tube may be sized smaller than the first port such that two passages are defined therethrough: a first passage (48) defined about an exterior of the tube; and a second passage (49) defined through an interior of the tube.