Hydrogen Combustor Mixing Passages With Baffles Against Flashback
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Solution Overview
Problem
The use of hydrogen as a fuel in gas turbine engines poses challenges due to its gaseous state and higher flammability, leading to potential flashback issues if the local flame speed exceeds the fuel-air mixture inlet speed.
Innovation Solution
A combustor design featuring a tortuous flow path with baffles and baffle injectors to delay ignition and promote uniform mixing of hydrogen and air, incorporating a non-planar inner face and varying passage lengths to stabilize the flame and prevent flashback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hydrogen is used as fuel in gas turbine engines, then energy efficiency and emissions are improved, but flashback risk increases due to higher flame speed
Solution Approach 1:
The mixing body is divided into multiple mixing passages with baffles that segment the flow path. This segmentation creates multiple small mixing zones rather than a single large chamber, allowing better control of flame propagation and reducing flashback risk while maintaining efficient combustion of hydrogen fuel.
Solution Approach 2:
Baffles are introduced to create a three-dimensional tortuous flow path within the mixing passages. This adds a spatial dimension to the mixing process, forcing the flame to travel a longer, more complex path that prevents flashback while maintaining combustion efficiency.
2Device complexity
If simple mixing passages are used, then device complexity is reduced, but mixing uniformity and flame stability deteriorate
Solution Approach 1:
The baffles create curved and tortuous flow paths within the mixing passages, replacing simple straight channels. This curvature forces the fuel-air mixture to follow a complex trajectory, enhancing mixing uniformity and stabilizing the flame by preventing direct flame propagation while maintaining relatively simple overall structure.
3Loss of energy
If straight mixing passages are used, then pressure loss is reduced, but mixing uniformity and flashback prevention deteriorate
Solution Approach 1:
By introducing baffles that create three-dimensional tortuous paths, the design prevents flashback without requiring excessively long straight passages. The additional spatial dimension allows the flame to be contained and controlled, achieving flashback prevention with moderate pressure loss.
Solution Approach 2:
The mixing passages are segmented by baffles into multiple short sections rather than one long straight passage. This segmentation prevents flashback by blocking direct flame propagation paths while keeping individual passage sections short enough to minimize pressure loss.
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 effectively stabilizes the flame and prevents flashback, ensuring safe and efficient combustion of hydrogen in gas turbine engines.
Implementation Method 1
A combustor design featuring a tortuous flow path with baffles and baffle injectors to delay ignition and promote uniform mixing of hydrogen and air
Implementation Method 2
There are fuel openings in the mixing passages that allow the fuel to flow from the plenum into the mixing passages
Data Source
Figure 1
Figure 2A~3
AI summary
A combustor (26; 100; 105) for a gas turbine engine (20) includes a liner (102) surrounding a fuel and air mixing body (104). A gaseous fuel supply passage (110) delivers gaseous fuel into the mixing body (104). A wall (111) of the mixing body (104) has air openings (112) to communicate air into mixing passages (114). At least one fuel opening (122) in each of the mixing passages (114) allows fuel to flow into the mixing passages (114) and mix with the air. There are passage sections (116) downstream of a location of the fuel openings (122), such that the mixed air and fuel travel downstream of the location and into a combustion chamber (105). The passage sections (116) have baffles (118, 120) that create a tortuous path. A gas turbine engine (20) is also disclosed.