Segmented Fuel Nozzle Tip for Flame Stabilization
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Solution Overview
Problem
Inadequate mixing in gasifiers of IGCC power generation systems leads to flame attachment issues, increased temperature of fuel nozzle tips, and elevated carbon monoxide emissions due to improper fluid mixing, causing vortex breakdown and shifting of the recirculation stability zone.
Innovation Solution
A fuel nozzle tip design featuring a fuel tube with circumferentially-spaced fuel openings and an air collar with circumferentially-spaced air openings, configured to discharge a fuel-air mixture with a weak swirl into the combustor mixing zone, reducing the likelihood of vortex breakdown and stabilizing the flame further downstream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fluid mixing is inadequate in the gasifier, then syngas production is maintained, but flame attachment occurs proximate to the fuel nozzle tip causing increased temperature
Solution Approach 1:
The fuel tube is divided into multiple sections with different opening patterns. The first section has a first pattern of openings and the second section has a second pattern of openings, creating staged mixing zones that progressively blend fuel and air to prevent premature flame attachment while maintaining stable combustion
Solution Approach 2:
Different sections of the fuel tube have locally optimized opening patterns tailored to their specific function. The first section uses a first pattern suitable for initial mixing, while the second section uses a second pattern for further mixing, allowing each local region to perform its specific mixing task effectively
2Stability of the object's composition
If fluid mixing is improper, then vortex breakdown probability increases, but recirculation stability zone shifts downstream causing flame detachment
Solution Approach 1:
The fuel tube is segmented into first and second sections with different opening patterns, creating staged mixing zones that progressively develop the flow structure. This staged approach stabilizes the recirculation zone at the desired location while ensuring complete mixing to prevent CO emissions and vortex breakdown
Solution Approach 2:
The opening patterns change between sections, modifying flow parameters such as velocity distribution and mixing intensity. This parameter change strategy controls the development of the recirculation zone position and prevents harmful flow instabilities
3Reliability
If flame attachment occurs within the nozzle, then mixing may be improved, but fuel nozzle tip temperature increases
Solution Approach 1:
By segmenting the fuel tube into sections with different opening patterns, the combustion process is distributed along the tube length rather than concentrating heat at the tip. This ensures reliable combustion while keeping the nozzle tip temperature within acceptable limits
Solution Approach 2:
The opening patterns are arranged in different axial sections rather than uniformly distributed, creating a dimensional distribution of mixing and combustion zones. This spatial arrangement allows stable flame attachment away from the tip while protecting the tip from excessive temperature
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 facilitates the production of a rich flame while minimizing flame-holding issues, reducing the operating temperature of the fuel nozzle tip and lowering carbon monoxide emissions by ensuring proper mixing and stabilizing the flame attachment.
Implementation Method 1
Controlling the mixing of fluids delivered to a gas turbine engine may be critical to the engine's performance and/or emissions
Data Source
AI summary
A fuel nozzle tip for use with a combustor and a method of assembling the fuel nozzle tip are provided. The fuel nozzle tip includes a fuel tube and an air collar coupled to the fuel tube. The fuel tube includes a first plurality of circumferentially-spaced fuel openings and a second plurality of circumferentially-spaced fuel openings. The fuel tube is configured to channel fuel into a mixing zone defined within the combustor. The air collar includes a plurality of circumferentially-spaced air openings configured to discharge air into the mixing zone.