Hydrogen Fuel Injector Panels with Micromixers for Low-NOx Combustion
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Solution Overview
Problem
Fuel injection and combustion of hydrogen gas in gas turbine engines pose risks related to nitrogen oxide emissions, flashback, and flame-holding events.
Innovation Solution
A micromixer panel with channels and fuel jets is integrated into the fuel injection system, providing fluid communication and mixing of hydrogen fuel with air, stabilized by a central pilot body and grommet, to enhance combustion stability and reduce emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hydrogen fuel is injected and combusted in gas turbine engines, then energy efficiency and clean combustion are improved, but nitrogen oxide emissions, flashback, and flame-holding events increase
Solution Approach 1:
The fuel injection system is divided into multiple separate injector modules arranged circumferentially, each with its own fuel injection nozzle and mixing chamber. This segmentation allows precise control of fuel distribution and mixing zones, enabling complete combustion at lower temperatures that reduces nitrogen oxide formation while maintaining energy efficiency
Solution Approach 2:
Each injector module features localized mixing chambers with specific geometric configurations that create optimal fuel-air mixing conditions at the injection point. The micro-mixing nozzles with radially oriented axes provide localized intense mixing that ensures complete combustion before heat transfer to combustion chamber walls, reducing thermal NOx emissions
2Use of energy by moving object
If hydrogen fuel is injected and combusted in gas turbine engines, then energy efficiency is improved, but flashback and flame-holding events increase
Solution Approach 1:
The mixing chamber geometry and fuel injection parameters are designed to create dynamic mixing conditions that adapt to varying operating conditions. The radially oriented micro-mixing nozzles create turbulent mixing that maintains flame stability across a wide range of flow rates, preventing both flashback and flame-holding events while sustaining efficient combustion
Solution Approach 2:
The mixing chamber acts as an intermediary zone between fuel injection and combustion chamber. This intermediate mixing region ensures thorough fuel-air mixing before combustion initiates, creating a homogeneous mixture that burns cleanly and efficiently without causing flashback to the injector or flame-holding in the combustion chamber
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 system effectively mixes and injects hydrogen fuel, stabilizing combustion and reducing nitrogen oxide emissions, while allowing for modular installation and repair of components.
Implementation Method 1
each of the plurality of channels provides fluid communication from one of a plurality of inlets on the first side to one of a plurality of outlets on the second side
Implementation Method 2
a plurality of fuel jets, wherein each of the plurality of fuel jets is positioned within a respective one of the plurality of outlets
Implementation Method 3
stabilized by a central pilot body and grommet, to enhance combustion stability and reduce emissions
Implementation Method 4
providing fluid communication and mixing of hydrogen fuel with air
Data Source
AI summary
Fuel injection for hydrogen-gas fuels poses risks with regard to emissions, flashback, and flame-holding events in a gas turbine engine. Accordingly, embodiments of a fuel injection system are disclosed that uniformly mix gas and fuel, while stabilizing a flame and facilitating maintenance. The fuel injection system may comprise a plurality of micromixer panels, mounted in windows of a frame that are arranged circumferentially around a longitudinal axis of the gas turbine engine. Each micromixer panel may comprise a plurality of axial channels, arranged around a central pilot body that is fixed in a grommet. Two or more internal fuel feeds may supply fuel to distinct subsets of fuel jets within the outlets of the axial channels, such that the fuel injection system may be operated in multiple stages.