Gas Turbine Combustor Nozzle Design for Flame Stability
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Solution Overview
Problem
In gas turbine engine combustion systems, lean blow-out issues arise due to fuel rich environments caused by diffusion fuel concentration, leading to increased liner wall temperatures and premature wear of combustor hardware, which are costly to mitigate with thermally resistant components.
Innovation Solution
A method and nozzle design that channel diffusion fuel at an injection angle greater than 30° to ensure leaner fuel-air mixtures, reducing the need for premixed fuel injection before turbine full-speed and minimizing liner wall temperature non-uniformity, while maintaining stable combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diffusion fuel is injected through fuel nozzles to reduce lean blow-out, then flame stability is improved, but fuel rich environment causes rich blow-out and increased liner wall temperature
Solution Approach 1:
The fuel injection system is segmented into multiple nozzles, each with multiple outlet passageways arranged in different directions. This segmentation distributes the fuel injection across multiple zones, preventing localized fuel-rich conditions that cause high liner wall temperatures while maintaining overall flame stability.
Solution Approach 2:
Different outlet passageways within each nozzle are oriented at different angles (e.g., 0°, 45°, 90°) to create locally optimized fuel-air mixing patterns. This local quality variation ensures proper fuel distribution in different combustion zones, preventing both lean blow-out and rich blow-out conditions.
2Reliability
If premixed fuel is injected before turbine full-speed to compensate for fuel rich environment, then rich blow-out is prevented, but flame instability increases and more fuel is required
Solution Approach 1:
The nozzle design incorporates dynamic fuel distribution through multiple outlet passageways that can adapt to different operating conditions. The varied injection angles create dynamic mixing patterns that maintain flame stability across different turbine speeds, eliminating the need for premixed fuel injection.
3Stability of the object's composition
If disproportionate amount of premixed fuel is supplied to one nozzle, then flame stability is improved, but local liner wall temperature increases and hardware wear accelerates
Solution Approach 1:
Each nozzle is designed with multiple outlet passageways having different orientations (0°, 45°, 90° angles) to create locally optimized fuel distribution. This local quality variation ensures uniform heat distribution across the liner wall, preventing localized thermal wear while maintaining flame stability.
Solution Approach 2:
Multiple outlet passageways within each nozzle are merged into a single integrated nozzle structure. This merging of multiple injection streams creates a balanced fuel distribution pattern that prevents excessive concentration in any single location, reducing thermal wear on surrounding hardware.
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 approach reduces the risk of rich blow-out, decreases liner wall temperature, and minimizes hardware wear by maintaining a stable and uniform combustion environment, thereby extending component lifespan and reducing maintenance costs.
Implementation Method 1
diffusion fuel injected through fuel nozzles may become concentrated downstream from the fuel injection nozzles
Implementation Method 2
igniting the first fluid within the combustor assembly downstream from the first nozzle
Data Source
AI summary
A method for operating a gas turbine engine including a combustor assembly includes channeling a first fluid through a plurality of first nozzles into the combustor and igniting the first fluid downstream from the first nozzles. The method also includes increasing the operating speed of the engine and attaining a first predetermined percentage of a baseload by channeling the first fluid only through the first nozzles and then channeling a second fluid through a second nozzle into the combustor. The method also includes igniting the second fluid within the combustor downstream from the second nozzle. The method further includes channeling the second fluid to the first nozzles when the engine attains a second predetermined percentage of the baseload. The second predetermined percentage of the baseload is greater than the first predetermined percentage of the baseload. The method also includes terminating a flow of the first fluid through the first nozzles.