Multi-Nozzle Burner Layout for Low-NOx Compact Combustion Chambers
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Solution Overview
Problem
Existing burners in reduced-size combustion chambers face challenges in achieving low NOx emissions due to increased surface density of peripheral power and limited effectiveness of internal combustion gas recirculation and fuel staging techniques, while also requiring stable and adjustable flames.
Innovation Solution
A burner design with central and peripheral nozzles, each equipped with oxidizer and fuel supply, including upstream and end injectors, and flame stabilizers, optimized for fuel pre-mixing and local enrichment, allowing for NOx emissions below 10 ppm in small combustion chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the combustion chamber size is reduced, then the burner becomes more compact and easier to install, but the surface density of peripheral power increases leading to higher NOx emissions
Solution Approach 1:
The burner is divided into multiple independent nozzles (central nozzle and peripheral nozzles), each capable of independent fuel and oxidizer injection. This segmentation allows precise control of combustion zones and enables local optimization of mixing ratios to reduce NOx formation while maintaining compact dimensions
Solution Approach 2:
Different nozzles are equipped with different configurations of fuel and oxidizer injectors to create local variations in mixing quality. The central nozzle and peripheral nozzles have distinct injection patterns that optimize combustion locally, reducing peak temperatures and NOx emissions in specific zones while maintaining overall combustion efficiency
2Object-generated harmful factors
If internal combustion gas recirculation is used, then flame temperature is reduced to lower NOx formation, but the technique is ineffective in reduced-size combustion chambers
Solution Approach 1:
Fuel and oxidizer are pre-mixed in controlled ratios before entering the combustion zone through multiple nozzles. This preliminary mixing action ensures optimal combustion conditions are achieved beforehand, reducing the need for post-combustion adjustments and enabling effective NOx control in compact chambers where gas recirculation is limited
3Object-generated harmful factors
If fuel staging is implemented, then NOx formation is reduced through controlled combustion zones, but the device complexity increases
Solution Approach 1:
Each nozzle assembly serves multiple functions: fuel injection, oxidizer injection, pre-mixing, and flame stabilization. This multi-functionality eliminates the need for separate staging mechanisms while achieving controlled combustion zones, thereby reducing device complexity compared to traditional fuel staging systems
4Object-generated harmful factors
If the peripheral injection diameter is increased, then the surface density of peripheral power decreases reducing NOx, but the burner apparent diameter increases
Solution Approach 1:
The burner transitions from a two-dimensional planar arrangement to a three-dimensional configuration with nozzles positioned at different radial distances and heights. This dimensional change allows increased peripheral injection diameter without proportionally increasing the burner's projected apparent diameter, thereby reducing surface density of peripheral power and NOx emissions while maintaining compact外形
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 burner achieves stable combustion with reduced NOx emissions and controlled flame size, minimizing CO emissions and excess air, while maintaining efficient operation in compact chambers.
Implementation Method 1
each having at least one upstream fuel injector in order to pre-mix the fuel and the oxidizer in the nozzle
Implementation Method 2
an end injector to inject fuel at the end of the peripheral nozzle
Implementation Method 3
the peripheral nozzles each have a flame stabilizer located at the end of the peripheral nozzle designed to exit in the combustion chamber
Implementation Method 4
The burner achieves stable combustion with reduced NOx emissions
Data Source
AI summary
A burner designed to be fitted in a combustion chamber, the burner including:a central nozzle configured to have an oxidizer and fuel supply;several peripheral nozzles configured to have an oxidizer and fuel supply and which each have at least one upstream fuel injector in order to pre-mix the fuel and the oxidizer in the nozzle;at least one oxidizer input connected to the said central and/or peripheral nozzles;wherein peripheral nozzles each have a flame stabilizer located at the end of the peripheral nozzle designed to exit into the combustion chamber, as well as a tip injector to inject fuel at the end of the peripheral nozzle.