Adjustable Oxygen Lance Low-NOx Burner
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Solution Overview
Problem
Existing Low-NOx burners face challenges in reducing nitrogen oxides (NOx) emissions, which are influenced by flame temperature, fuel composition, and the conversion of nitrogen compounds during combustion.
Innovation Solution
The burner design incorporates an adjustable oxygen lance that ejects oxygen into a colder flue gas region surrounding the flame, enhancing flue gas recirculation and reducing NOx emissions by cooling the flame and lowering oxygen partial pressure, while maintaining stoichiometric or sub-stoichiometric combustion conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the flame temperature is reduced to lower NOx emissions, then thermal NOx production is limited, but combustion efficiency and flame stability deteriorate
Solution Approach 1:
The combustion process is segmented into multiple zones with different oxygen concentrations. The burner introduces oxygen at different stages and locations, creating a staged combustion approach where fuel burns in oxygen-deficient conditions first, then completes combustion in oxygen-rich zones. This segmentation allows temperature control to reduce NOx while maintaining overall combustion efficiency.
Solution Approach 2:
The burner performs preliminary combustion actions by introducing oxygen at specific locations and times before the main combustion zone. The oxygen lance positions oxygen supply in advance in regions where it can promote complete combustion without creating peak temperatures that generate NOx, thereby preparing conditions for efficient combustion while controlling emissions.
2Productivity
If oxygen is supplied to enhance combustion efficiency, then burning completeness improves, but flame temperature increases and thermal NOx formation is promoted
Solution Approach 1:
The burner applies local quality by supplying oxygen at specific locations rather than uniformly throughout the combustion chamber. The oxygen lance positions oxygen supply in specific zones where it can enhance combustion efficiency without creating high-temperature regions that promote thermal NOx formation. Different regions have different oxygen concentrations tailored to their specific combustion needs.
Solution Approach 2:
The system performs preliminary oxygen supply actions in zones where oxygen is needed for complete combustion but where high temperatures would not occur. This preliminary action ensures efficient burning while avoiding conditions that lead to thermal NOx formation.
3Device complexity
If a fixed oxygen lance position is used, then device complexity is reduced, but adaptability to different combustion conditions deteriorates
Solution Approach 1:
The oxygen lance mounting is made dynamic and adjustable rather than fixed. The lance can be positioned at different locations along the burner axis and angled at different orientations to adapt to varying combustion conditions, fuel types, and operational requirements. This dynamic capability allows the same device to optimize performance across multiple operating scenarios.
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 effectively reduces NOx emissions by promoting flue gas recirculation and optimizing combustion conditions, stabilizing the flame and spreading it over a wider area, thus lowering peak flame temperatures and improving combustion efficiency.
Implementation Method 1
enhancing flue gas recirculation and reducing NOx emissions by cooling the flame
Implementation Method 2
reducing NOx emissions by cooling the flame and lowering oxygen partial pressure
Implementation Method 3
generating a flame by combustion of a fuel
Data Source
AI summary
A burner is provided which includes a tile surrounding an opening of the tile extending along a burner axis, the tile including a front side and a rear side, wherein the rear side has an air inlet connected to the opening for feeding air into the opening, and the front side has a discharge outlet connected to the opening for discharging a flame into a surrounding area. The burner includes at least one oxygen lance extending along the burner axis in a first recess of the tile, and the oxygen lance having an ejection nozzle at an end region of the lance for ejecting oxygen, wherein the at least one oxygen lance is mounted with the ejection nozzle positioned along the burner axis to be adjustable between an uppermost position and a lowermost position via a zero-position in between the uppermost position and the lowermost position.