Helical Combustor Mixing Passage for Hydrogen Burn-Back Control
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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 increased flammability, which can lead to burn back issues if ignition occurs too close to the fuel feed, and existing combustor structures designed for aviation fuel may not be suitable.
Innovation Solution
A combustor design featuring a helix-shaped air and fuel mixing passage within a frusto-conical inner and intermediate housing members, combined with a swirler effect from an outer passage, enhances mixing efficiency and reduces the risk of burn back by increasing fluid velocity and swirl, utilizing hydrogen as a fuel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hydrogen is used as fuel in gas turbine engines, then fuel efficiency and environmental performance are improved, but burn back risk increases due to gaseous state and increased flammability
Solution Approach 1:
The patent employs helical (curved) mixing passages instead of straight passages to induce swirl flow. This curvature creates rotational motion that increases mixing efficiency and maintains higher fluid velocity throughout the passage, preventing flame propagation back toward the fuel injection point while still enabling complete combustion of hydrogen fuel
2Productivity
If ignition occurs close to fuel feed for efficient combustion, then combustion efficiency is improved, but burn back risk increases
Solution Approach 1:
The helical mixing passage acts as an intermediary element between fuel injection and combustion chamber. It provides a controlled environment where fuel and air mix thoroughly through swirl-induced turbulence, ensuring efficient combustion can occur downstream while the passage geometry itself prevents direct flame propagation to the fuel source
3Device complexity
If existing combustor structures designed for aviation fuel are used, then structural simplicity is maintained, but mixing efficiency decreases for hydrogen fuel
Solution Approach 1:
The patent changes the geometric parameters of the mixing passages from straight to helical configurations. This modification alters the flow characteristics to induce swirl, which significantly improves mixing efficiency for gaseous hydrogen fuel while maintaining a relatively simple overall combustor structure that can be integrated into existing gas turbine engines
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 ensures reliable mixing and reduces the likelihood of burn back by increasing fluid velocity and swirl, providing a safer and more efficient combustion process for hydrogen fuel in gas turbine engines.
Implementation Method 1
A combustor design featuring a helix-shaped air and fuel mixing passage within a frusto-conical inner and intermediate housing members, combined with a swirler effect from an outer passage, enhances mixing efficiency and reduces the risk of burn back by increasing fluid velocity and swirl
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3B
AI summary
A combustor (98) includes a combustor liner (102) defining a combustion chamber (105) and a fuel and air mixing body (104) connected to the combustor liner (102) to deliver mixed fuel and air into the combustion chamber (105). The mixing body (104) includes an inner housing member (103) centered on a center axis (X) and an intermediate housing member (131). A mixing passage (112) is defined between the inner and intermediate housing members (103, 131). The mixing passage (112) extends along a direction from an upstream end (119, 114) to a downstream end (120, 116) with a circumferential component, a component in an axially downstream direction, and a radially inward component with at least one air inlet (118) into the mixing passage (112). A fuel supply (99) extends into the mixing passage (112) at a location downstream of the air inlet (118). The mixing passage (112) extends downstream to supply fuel and air into the combustion chamber (105). A gas turbine engine (20) is also disclosed.