Slidable Multi-Cone Premix Burner for Gas Turbine Combustion
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Solution Overview
Problem
Current combustor arrangements in gas turbines face issues with axial movement of burners due to thermal expansion, leading to air leakages and flow disturbances that affect the oxidation process and NOx formation, as the seals near the flame are not tight and cause local quenching effects.
Innovation Solution
A combustor arrangement featuring a multi-cone premix burner connected to a front panel via a sealed sliding joint, comprising a cylindrical burner ring and sleeve with a seal positioned upstream of the mixing zone, and purge air holes to prevent flame stabilization at the burner ring exit, allowing axial movement while minimizing leakage influence on the oxidation process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a sealed sliding joint is positioned near the flame to allow axial movement of the burner, then the burner can compensate for thermal expansion, but air leakages occur that cause local quenching effects and disturb the oxidation process
Solution Approach 1:
The sealing function is extracted from the flame zone and relocated to the upstream end of the burner ring, away from the hazardous oxidation process. The sliding joint is positioned at the upstream end where leakage air can be purged through dedicated holes before entering the mixing zone, thus removing the harmful effect of air leakage from the critical flame area.
Solution Approach 2:
Purge air holes act as an intermediary mechanism that allows controlled introduction of air into the mixing zone upstream of the flame. This mediator converts the potentially harmful leakage air into a useful component of the premix, allowing it to be properly mixed and burned without causing local quenching or disturbing the oxidation process.
2Reliability
If seals are made tight to prevent air leakages, then the oxidation process is protected, but the burner cannot move axially to compensate for thermal expansion
Solution Approach 1:
The burner structure is segmented into a movable burner ring and a stationary burner sleeve, with the sealing function isolated to a specific location at the upstream end. This segmentation allows the burner ring to move axially for thermal expansion compensation while maintaining a controlled sealing interface that prevents harmful leakages from reaching the flame zone.
Solution Approach 2:
The sealing arrangement is designed to be dynamic rather than static, allowing axial movement of the burner ring relative to the burner sleeve while maintaining sealing effectiveness. The seal accommodates thermal expansion through controlled movement, and the purge air holes dynamically manage leakage air to prevent harmful effects on the oxidation process.
3Object-affected harmful factors
If purge air holes are added to manage leakage air, then the harmful effects of leakage are reduced, but the device complexity increases
Solution Approach 1:
The burner sleeve is designed with multi-functionality, serving both as a structural component and as a mixing tube that incorporates the purge air holes. This universal design integrates the leakage management function into an existing component rather than adding a separate system, thereby reducing overall device complexity while still effectively managing harmful leakage air effects.
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 solution enables axial movement of the burner while ensuring that air leakages are purged and premixed with the fuel-air mixture upstream, reducing NOx and CO production by stabilizing the flame in the mixing zone formed by the burner sleeve, which improves air velocity profiles and prevents harmful leakage effects.
Implementation Method 1
a seal (32) of the sliding joint (24, 26) is positioned upstream of the mixing zone (24)
Implementation Method 2
purge air holes are provided in the burner sleeve downstream of the seal to purge the gap between burner ring and burner sleeve with air
Implementation Method 3
connected to said front panel though an elongated mixing zone in an axially moveable fashion by means of a sealed sliding joint
Implementation Method 4
multi-cone premix burner connected to a front panel via a sealed sliding joint, comprising a cylindrical burner ring and sleeve
Implementation Method 5
stabilizing the flame in the mixing zone formed by the burner sleeve, which improves air velocity profiles
Data Source
AI summary
A combustor arrangement includes a combustion chamber with a front panel, and a premix burner of the multi-cone type, which is connected to the front panel through an elongated mixing zone in an axially moveable fashion by a sealed sliding joint. A wide range of axial variation of the burner with a minimized influence of the leakage air flow on the oxidation process within the flame is achieved by positioning the sealed sliding joint upstream of the mixing zone.