Ribbed Fuel Injection Assembly for Hydrogen Combustor Flashback
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Solution Overview
Problem
Traditional gas turbine combustors struggle with burning high levels of hydrogen and/or pure hydrogen, leading to flashback or flame holding conditions, which can cause severe damage to the injectors, and fail to meet stringent NOx emission regulations.
Innovation Solution
A fuel injection assembly with a unique configuration featuring a deflection member, ribs, and fuel plenum that enhances turbulent mixing of air and fuel, minimizing flashback and flame holding conditions, and is designed for axial fuel staging combustors to efficiently burn alternative fuels like hydrogen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If traditional combustion systems burn high levels of hydrogen and/or pure hydrogen, then NOx emissions are significantly reduced or eliminated, but flashback or flame holding conditions occur causing severe damage to the injector
Solution Approach 1:
The patent introduces a recirculation passage that pre-mixes a portion of the fuel with air before it reaches the combustion zone. This preliminary mixing action creates a controlled fuel-air mixture that prevents flashback and flame holding conditions while enabling efficient hydrogen combustion. The recirculation passage acts as a pre-mixing chamber that prepares the mixture before combustion occurs.
Solution Approach 2:
The recirculation passage serves as an intermediary element between the fuel injection and the combustion zone. It mediates the fuel-air mixing process by providing a dedicated pathway for controlled premixing, thereby preventing direct flashback to the injector while maintaining efficient combustion. This intermediary structure resolves the contradiction by decoupling the fuel injection from the combustion zone.
2Adaptability or versatility
If traditional AFS fuel injectors are used with high levels of hydrogen, then the combustion system can handle alternative fuels, but flashback or flame holding conditions migrate towards the fuel supply causing severe damage
Solution Approach 1:
The recirculation passage performs preliminary fuel-air mixing before the mixture enters the main combustion zone. This pre-mixing action ensures that hydrogen and air are properly combined in controlled proportions, preventing flashback conditions from migrating towards the fuel supply. The preliminary mixing occurs in a controlled environment away from the injector.
Solution Approach 2:
The recirculation passage acts as an intermediary structure that separates the fuel injection system from the combustion zone. It provides a dedicated mixing chamber that handles the volatile hydrogen-fuel mixing process, protecting the injector from exposure to flashback conditions while maintaining adaptability to burn high levels of hydrogen.
3Power
If fuel and air are mixed and burned in traditional combustors, then combustion gases are generated for turbine work, but NOx and other pollutants are created and expelled
Solution Approach 1:
The recirculation passage performs preliminary mixing of fuel and air in a controlled manner before combustion occurs. This pre-mixing ensures more complete and efficient combustion, generating sufficient power for turbine work while reducing the formation of NOx and other pollutants by optimizing the fuel-air ratio before the combustion zone.
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 assembly ensures efficient and complete ignition of the fuel-air mixture in the secondary combustion zone, reducing emissions and preventing damage while meeting low NOx emission standards.
Implementation Method 1
A fuel injection assembly with a unique configuration featuring a deflection member, ribs, and fuel plenum that enhances turbulent mixing of air and fuel
Data Source
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AI summary
A fuel injection assembly (100) for a combustor (10) of a gas turbine engine (1000) comprises a body (202) with a head section (204) defining an air intake chamber (206), a mixing chamber (226) disposed adjacent the air intake chamber and comprising transverse end walls (228) and longitudinal side walls (230), a deflection member (212) disposed in the air intake chamber (206) and comprising a deflection surface (214) and sides (216) spaced from inner wall surfaces (210) of the air intake chamber (206) such that peripheral air passages (222) are defined between the deflection member (212) and the inner wall surfaces (210) of the air intake chamber (206) for air to pass from the air intake chamber (206) into the mixing chamber (226), a plurality of ribs (236) disposed along an inner surface of each of the longitudinal side walls (230) of the mixing chamber (226), extending along a direction from the air intake chamber (206) towards an outlet end (232) of the mixing chamber (226) and being spaced apart along a direction between the transverse end walls (228), a fuel plenum (242) disposed along the longitudinal side walls (230) of the mixing chamber (226), and a first plurality of fuel injection holes (246) defining a passage from the fuel plenum (242) through the longitudinal side walls (230) of the mixing chamber (226) and through at least some of the ribs (226).