Micro-mixer Bundle Combustor for Hydrogen Flashback Prevention
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Solution Overview
Problem
Gas turbines experience combustion instability due to high-frequency resonance caused by hydrogen-containing fuels, leading to issues like spontaneous ignition and flashback, which existing technologies struggle to address effectively.
Innovation Solution
A micro-mixer bundle assembly is introduced, featuring micro-mixers with varying outlet cross-sectional shapes and inclined flow paths to reduce radiant heat transfer from the combustion chamber, preventing spontaneous ignition and flashback by efficiently mixing hydrogen-containing fuels with air, and arranging micro-mixer bundles in a radial direction to stabilize combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hydrogen-containing fuel is used to improve energy efficiency, then combustion stability deteriorates due to high-frequency resonance
Solution Approach 1:
The combustor is divided into multiple combustion zones with different outlet cross-sectional shapes (circular, rectangular, triangular, etc.). Each zone processes hydrogen-containing fuel independently, preventing synchronized high-frequency resonance across the entire combustor. This segmentation disrupts the formation of uniform resonance patterns while maintaining efficient combustion of hydrogen fuel.
Solution Approach 2:
Different combustion zones are designed with asymmetric outlet cross-sectional shapes rather than uniform circular shapes. This asymmetry creates varied flow characteristics and resonance frequencies in different zones, preventing the establishment of a single dominant high-frequency resonance mode that would destabilize hydrogen combustion.
2Productivity
If micro-mixers are used to improve fuel-air mixing efficiency, then radiant heat transfer to inlet flow path increases causing spontaneous ignition
Solution Approach 1:
The flow path is designed with a three-dimensional inclined configuration rather than a simple linear path. The inlet flow path is inclined relative to the outlet flow path, creating a spatial separation that increases the distance between the combustion chamber and the mixed fuel-air mixture. This dimensional change reduces radiant heat transfer while maintaining effective mixing through the inclined flow path geometry.
Solution Approach 2:
The inclined flow path acts as an intermediary structure between the combustion chamber and the fuel-air mixing zone. This intermediate inclined passage shields the mixed mixture from direct radiant heat exposure while still allowing thermal energy transfer necessary for combustion initiation, preventing spontaneous ignition caused by excessive radiant heat.
3Device complexity
If conventional combustor design is used to simplify structure, then combustion instability occurs due to resonant frequency
Solution Approach 1:
Rather than redesigning the entire combustor structure, only the outlet cross-sectional shapes of individual combustion zones are varied while maintaining the overall simple combustor geometry. This localized modification introduces structural diversity where needed (different zone shapes) while preserving global structural simplicity, preventing resonance without excessive complexity.
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 solution effectively mitigates combustion instability and prevents radiant heat transfer, enhancing the mixing efficiency and stability of hydrogen-containing fuels, thereby reducing the occurrence of spontaneous ignition and flashback in gas turbines.
Implementation Method 1
an inclined flow path connecting the inlet flow path and the outlet flow path and formed inclined at a predetermined angle to reduce transfer of radiant heat by a flame generated in the combustion chamber to the inlet flow path
Implementation Method 2
the first fluid introduced through the inlet portion and the second fluid fed through the feed hole are mixed to form a fluid mixture which is injected into a combustion chamber
Implementation Method 3
a combustion chamber assembly including a combustion chamber in which a fuel fluid combusts
Data Source
AI summary
A micro-mixer bundle assembly and a combustor and a gas turbine having the same are provided. The micro-mixer bundle assembly includes a plurality of micro-mixers, each of the plurality of micro-mixers including an inlet portion formed on one side and through which a first fluid is introduced and a feed hole formed in a circumferential wall and through which a second fluid is fed, wherein the first fluid introduced through the inlet portion and the second fluid fed through the feed hole are mixed to form a fluid mixture which is injected into a combustion chamber, and a plurality of micro-mixer bundles, each of the plurality of micro-mixer bundles including the plurality of micro-mixers arranged therein, wherein a cross-sectional shape of an outlet of the micro-mixers disposed in one of the micro-mixer bundles is different from a cross-sectional shape of an outlet of the micro-mixers disposed in the other micro-mixer bundles.