Premixing Direct Injector Nozzle for Hydrogen Fuel
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Solution Overview
Problem
Gas turbine engines using fuels with higher reactivity, such as hydrogen, face issues with non-uniform fuel-air mixing and potential ignition within the injector due to inadequate thermal energy transfer, leading to undesirable pollutant emissions and potential damage.
Innovation Solution
A Premixing Direct Injector (PDI) nozzle design with a baffle member and cooling features, such as mixing tubes and cooling fins, ensures uniform fuel-air mixing and prevents ignition by maintaining fuel flow velocity and cooling the mixing tubes, ensuring the fuel-air mixture is injected into the combustor without igniting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fuel nozzles are designed for natural gas fuels, then the nozzle structure is optimized for lower reactivity fuels, but the nozzle cannot effectively handle higher reactivity fuels like hydrogen due to inadequate thermal energy transfer and non-uniform mixing
Solution Approach 1:
The fuel nozzle is divided into multiple sections: a fuel injection section, a mixing section with cooling fins, and a combustion section. This segmentation allows each section to perform its specific function - the mixing section with cooling fins prevents premature ignition while the combustion section allows controlled burning, thus enabling the nozzle to handle high-reactivity fuels like hydrogen safely
Solution Approach 2:
Cooling fins are introduced as an intermediary thermal management component between the fuel injection and combustion sections. These fins actively remove thermal energy from the fuel-air mixture during the mixing process, preventing spontaneous ignition of high-reactivity fuels while maintaining the structural integrity and functionality of the nozzle
2Device complexity
If fuel and air are mixed in the combustor, then the injection process is simple, but the mixture is non-uniform resulting in higher temperatures and pollutant emissions
Solution Approach 1:
The fuel and air are premixed in a dedicated mixing section before entering the combustion chamber. This preliminary mixing action ensures uniform fuel-air distribution is achieved upstream of the combustor, preventing localized high-temperature zones and reducing pollutant emissions during combustion
Solution Approach 2:
The mixing section incorporates cooling fins with specific surface areas and distributions tailored to local thermal requirements. This local quality enhancement ensures uniform cooling and mixing across different zones of the fuel-air mixture, preventing hot spots that would lead to excessive emissions
3Reliability
If cooling features are added to prevent ignition, then thermal energy transfer is improved, but the device complexity increases
Solution Approach 1:
The cooling fins are merged with the mixing section structure rather than being separate components. This integration achieves thermal energy removal for ignition prevention while minimizing additional complexity, as the cooling features are incorporated into the existing mixing chamber geometry
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 PDI nozzle achieves uniform fuel-air mixing and prevents premature ignition within the injector, reducing pollutant emissions and extending the injector's lifespan by effectively managing thermal energy transfer and maintaining a stable fuel flow.
Implementation Method 1
cooling features, such as mixing tubes and cooling fins, ensures uniform fuel-air mixing and prevents ignition by maintaining fuel flow velocity and cooling the mixing tubes
Implementation Method 2
cooling the mixing tubes, ensuring the fuel-air mixture is injected into the combustor without igniting
Implementation Method 3
mixing tubes... ensures uniform fuel-air mixing
Implementation Method 4
mixing tubes and cooling fins, ensures uniform fuel-air mixing
Implementation Method 5
maintaining fuel flow velocity... prevents ignition
Data Source
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AI summary
A fuel injection nozzle (100) comprises a body member (102) having an upstream wall (104) opposing a downstream wall (106), a baffle member (108), a first chamber (112), a second chamber (110) communicative with the first chamber (112), a fuel inlet communicative with the first chamber (112) operative to emit a first gas into the first chamber (112), and a plurality of mixing tubes (114), each of the mixing tubes (114) having a first inlet (116) communicative with an aperture in the upstream wall operative to receive a second gas, a second inlet communicative with a tube outer surface and a tube inner surface operative to translate the first gas into the mixing tube, a mixing portion operative to mix the first gas and the second gas, and an outlet communicative with an aperture in the downstream wall operative to emit the mixed first and second gasses.