Fuel Mixer with Tangential Air Jets for Hydrogen Combustion
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Solution Overview
Problem
Conventional mixers for gas turbine engines are not well-suited for hydrogen fuels due to the risk of flame-holding and high temperatures, which can damage the mixer and combustor, and they fail to provide uniform mixing, leading to increased NOx and CO emissions.
Innovation Solution
A mixer design that injects fuel centrally or radially and introduces three air flows, including a central air flow and tangential air jets, to create high velocity zones and prevent fuel from approaching the wall, reducing flame-holding risk and achieving uniform mixing of hydrogen fuels with air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mixers are used for hydrogen fuels, then fuel mixing is achieved, but flame-holding occurs and high temperatures damage the mixer and combustor
Solution Approach 1:
The patent applies preliminary anti-action by introducing tangential air jets that create high velocity zones before the fuel-air mixture can contact the mixer walls, preventing flame-holding and high temperature damage in advance. The air jets are positioned to counteract the harmful effects before they occur
Solution Approach 2:
The patent uses air as an intermediary substance introduced through tangential jets to maintain a protective boundary between the fuel-air mixture and the mixer walls. This intermediary air flow prevents direct contact that would cause flame-holding and thermal damage
2Productivity
If conventional mixers are used, then fuel mixing occurs, but mixing is non-uniform leading to increased NOx and CO emissions
Solution Approach 1:
The patent applies local quality by introducing air flows at specific locations and angles (tangential jets at the periphery) to create localized high velocity zones that enhance mixing uniformity in critical areas, thereby reducing harmful emissions
Solution Approach 2:
The patent introduces tangential air flows that add a rotational dimension to the mixing process, creating swirling motion that enhances uniformity of fuel-air mixing and reduces emission hotspots
3Productivity
If fuel is allowed to approach the wall for mixing, then mixing efficiency increases, but flame-holding risk increases
Solution Approach 1:
The tangential air jets create preliminary protective action by establishing high velocity zones that prevent fuel from approaching the walls before mixing can occur, eliminating flame-holding risk while maintaining mixing efficiency
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 mixer design reduces flame-holding risk, NOx and CO emissions, and allows for the safe burning of hydrogen fuels at any percentage, including 100% hydrogen, by maintaining the fuel-air mixture away from the wall and boundary layer, resulting in compact flames and uniform downstream temperatures.
Implementation Method 1
introduces three air flows, including a central air flow and tangential air jets, to create high velocity zones
Implementation Method 2
maintaining the fuel-air mixture away from the wall and boundary layer
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A mixer (200) configured to provide a fuel-air mixture to a combustor of an engine is provided. The mixer comprises a mixer body (210) having an outer surface (212), an interior passage (220) and a central axis (201), and a fuel inlet (206) located parallel to the central axis (201), the fuel inlet (206) configured to introduce a fuel flow (C) to the interior passage (220) of the mixer body (210). The mixer (200) further comprises a central air jet (208) located parallel to the central axis (201), a first set of openings (202) inclined with respect to the central axis (201) and a second set of openings (204) having an inlet surface tangential to the mixer body (210), wherein the central air jet (208), the first set of openings (202) and the second set of openings (204) are each configured to introduce an air flow to the interior passage (220) of the mixer body (210).