Combustor Dilution Hole Layout for Hydrogen NOx Control
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Solution Overview
Problem
Existing combustors in turbine engines, particularly those designed for traditional fuels, are inadequate for hydrogen or hydrogen mixed fuels, leading to high NOx emissions due to high flame temperatures, and there is a need to reduce these emissions while maintaining efficiency.
Innovation Solution
A combustor design featuring multiple sets of dilution holes in the combustor liner, with varying orientations, diameters, and positions to control flame shape, temperature, and mixing patterns, reducing NOx emissions by enhancing airflow penetration and mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If hydrogen or hydrogen mixed fuel is used in the combustor, then the burning velocity and flammable range are improved, but the flame temperature increases leading to higher NOx emissions
Solution Approach 1:
The combustor is divided into multiple zones with different functions: a primary combustion zone for efficient burning and secondary zones with dilution holes for temperature control. The dilution holes are segmented into multiple rows (first row closer to combustion zone, second row farther away) that independently control different aspects of mixing and cooling, allowing separate optimization of combustion efficiency and NOx reduction.
Solution Approach 2:
Different regions of the combustor are given different properties: the primary combustion zone maintains high temperature for efficient hydrogen burning, while secondary regions introduce cooler air through dilution holes to create lower temperature zones that reduce NOx formation. The dilution holes have varying orientations and positions to create localized cooling effects where needed most.
2Object-generated harmful factors
If dilution air is introduced to reduce flame temperature and NOx emissions, then harmful emissions are reduced, but combustion efficiency may be compromised
Solution Approach 1:
Dilution air is introduced at strategically positioned dilution holes before the combustion products reach the turbine. The first row of dilution holes is positioned to cool the flow early in the combustion zone, while the second row provides additional cooling downstream. This preliminary cooling action reduces peak temperatures and NOx formation while maintaining sufficient energy release for efficient combustion.
Solution Approach 2:
The dilution holes are oriented in multiple directions (different angles) to introduce dilution air from various dimensions into the combustion flow. This multi-directional injection creates more uniform mixing and temperature distribution throughout the combustion chamber, enhancing both NOx reduction and combustion efficiency by ensuring thorough air-fuel mixing in three-dimensional space.
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 design achieves lower NOx emissions, better temperature control, and improved efficiency by optimizing the combustion process through controlled airflow and mixing, resulting in a more uniform temperature distribution and reduced NOx formation.
Implementation Method 1
A first set of dilution holes and a second set of dilution holes are formed through the combustor liner... The combustor includes a combustion chamber, a swirler, a fuel injector, a deflector... dilution air flows through the passages
Implementation Method 2
The combustor includes a combustion chamber, a swirler, a fuel injector, a deflector... air and fuel are mixed
Implementation Method 3
The fuel is burned in the presence of the air to produce hot gas... hydrogen or a hydrogen mixed fuel can result in a higher flame temperature
Data Source
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AI summary
A turbine engine (10) and method for controlling nitrogen oxides present within a combustor of the turbine engine (10). The turbine engine (10) having a compressor section (12), a combustion section (14), and a turbine section (16) in serial flow arrangement along an engine centerline (20). The combustion section (14) having a combustor liner (82, 182, 282, 382, 482) having a first end, a second end, opposing the first end, and at least partially defining a combustion chamber (86, 186, 286, 386, 486) extending between the first and second ends. A dome assembly (84, 184, 284, 384, 484) is mounted to the combustor liner (82, 182, 282, 382, 482) at the first end and defines a dome inlet (98, 198, 298, 398, 498) of the combustion chamber (86, 186, 286, 386, 486). There are multiple sets of dilution holes (90a, 90b, 190a, 190b, 190c, 190d, 290a, 290b, 390a, 390b, 490a, 490b) including a first set of dilution holes (90a, 290a, 390a, 490a) provided in the combustor liner (82, 182, 282, 382, 482) downstream from the dome inlet (98, 198, 298, 398, 498) and a second set of dilution holes (90b, 290b, 390b, 490b) provided in the combustor liner (82, 182, 282, 382, 482) between the first set of dilution holes and the dome inlet (98, 198, 298, 398, 498).