Segmented Burner Air Paths for Gas Turbine Emission Control
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Solution Overview
Problem
Existing gas turbine burner arrangements face challenges in achieving high efficiency while minimizing NOx and CO emissions and reducing pressure drop, as either higher NOx emissions occur with optimized flame temperature or lower efficiency results from minimizing NOx emissions.
Innovation Solution
A burner arrangement with two separate air flow paths, one connected to the plenum and the other to a combustor interspace, allowing for parallel or series air flow configurations to optimize air distribution and fuel mixing, reducing pressure drop and emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling path and burner air path are arranged in parallel, then the combustor walls are effectively cooled, but not all air participates in combustion resulting in higher flame temperature and increased NOx emissions
Solution Approach 1:
The air supply system is segmented into multiple independent flow passages (first flow passage from plenum, second flow passage from interspace) that can be controlled separately. This allows selective routing of cooling air versus combustion air to different destinations, enabling independent optimization of wall cooling and combustion efficiency to reduce NOx emissions.
Solution Approach 2:
The system dynamically adjusts air distribution by responding to differential pressure between plenum and interspace. When interspace pressure is sufficiently low, cooling air automatically flows through the second passage to the burner; when pressure equalizes, combustion air flows through the first passage. This dynamic switching optimizes both cooling and emission reduction based on real-time operating conditions.
2Object-generated harmful factors
If the cooling path and burner air path are connected in series, then all air massflow participates in combustion minimizing emissions, but overall pressure loss increases reducing engine efficiency
Solution Approach 1:
The air supply is divided into two separate flow passages with independent control paths. The first passage provides a pressure-driven bypass for combustion air when interspace pressure is high, avoiding excessive pressure loss. The second passage provides cooling air when interspace pressure is low. This segmentation allows the system to minimize pressure losses while still achieving emission reduction through selective air routing.
Solution Approach 2:
The system changes the flow path parameter based on the pressure differential parameter between plenum and interspace. When pressure difference is large, air flows through the second passage (cooling path). When pressure difference is small, air flows through the first passage (direct combustion path). This parameter-based switching optimizes the balance between emission control and pressure loss reduction.
3Loss of energy
If bypass air is used to reduce cooling path pressure loss, then some pressure loss is recovered, but the bypass air still experiences pressure loss providing no additional benefit
Solution Approach 1:
The interspace acts as an intermediary pressure-regulating chamber between the plenum and the burner. By controlling the pressure differential across the interspace, the system mediates air flow distribution between the two passages. This intermediary mechanism enables intelligent routing of air based on real-time pressure conditions, maximizing combustion efficiency while minimizing unnecessary pressure losses.
Solution Approach 2:
The system uses pressure differential as a control parameter to dynamically change the flow path. When interspace pressure is sufficiently low relative to plenum pressure, cooling air flows through the second passage. When pressures are more equal, combustion air flows through the first passage. This parameter-driven approach ensures optimal combustion efficiency while recovering pressure where possible.
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 design enables operation at higher temperatures with reduced NOx and CO emissions and lower pressure drop, enhancing efficiency and stability by adjusting air flow pressures and swirl patterns for improved fuel mixing.
Implementation Method 1
the combustor wall provides a combustor liner containing an interspace 9 into which compressed air 2 form the plenum 1 respectively form the compressor enters the interspace 9 for cooling purpose
Implementation Method 2
a part of compressed air inside the plenum 1 enters the burner section 3 via the means for air supply in form of access openings 6 inside the burner hood 4 for mixing with fuel
Implementation Method 3
one of the two flow passages is fed by a first supply pressure and the other flow passage is fed by a second supply pressure which is lower than the first supply pressure
Data Source
Figure 1~3
Figure 2a~2b
Figure 4a~4b
AI summary
The invention refers to burner arrangement for producing hot gases (8) to be expanded in a gas turbine, comprising a burner inside a plenum (1), said burner has means for fuel injection (5), means for air supply (6) and means for generating an ignitable fuel/air mixture inside the burner, and a combustion chamber (7) following downstream said burner having an outlet being fluidly connected to the gas turbine. The invention is characterized in that the means for air supply (6) comprise at least two separate flow passages (14, 15), and that the one of the two flow passages is fed by a first supply pressure (p1) and the other flow passage is fed by a second supply pressure (p2).