Gas Turbine Combustor Resonator Damping Vibration
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Solution Overview
Problem
Conventional gas turbines using premixed combustion methods face challenges in reducing combustion vibration, which leads to unstable combustion and increased nitrogen oxides (NOx) emissions, particularly in both high and low-frequency areas, requiring effective damping mechanisms that are not adequately addressed by existing resonators.
Innovation Solution
The implementation of a gas turbine combustor design featuring a cylinder body with a first box body and throat structure, incorporating a resistive element with multiple through-holes, which traps and resonates fluid particles to dampen combustion vibration, thereby reducing NOx emissions across various frequency ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a premixed combustion method is used to reduce NOx emissions, then nitrogen oxides generation is reduced, but combustion vibration increases causing unstable combustion
Solution Approach 1:
A resonator is introduced as an intermediary component between the combustion chamber and the exhaust system. The resonator captures combustion vibrations through its acoustic resonance characteristics and dissipates them, thereby stabilizing combustion without affecting the premixed combustion process that reduces NOx emissions
Solution Approach 2:
The resonator is designed to exploit mechanical vibration principles by creating a resonance frequency that matches the combustion vibration frequency. This causes the resonator to absorb vibrational energy from the combustion process, converting it into acoustic waves that are then damped, thereby reducing combustion instability
2Stability of the object's composition
If conventional resonators are used to dampen combustion vibration, then high-frequency vibration is reduced, but low-frequency vibration remains ineffective
Solution Approach 1:
The resonator design parameters (volume, throat area, neck length) are specifically optimized to tune the resonance frequency to match low-frequency combustion vibrations. This parameter adjustment enables the resonator to be effective in the low-frequency range where conventional resonators fail, while still maintaining high-frequency damping capabilities
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
This design effectively reduces combustion vibration and stabilizes NOx reduction, providing a comprehensive solution for both high and low-frequency areas without the limitations of conventional resonators.
Implementation Method 1
fluid particles which serve as vibration elements of combustion vibration that occurs in a combustion region resonate with air inside a first internal space
Implementation Method 2
vibrate around the first resistive element, thereby damping the vibration amplitude
Data Source
AI summary
In order to realize a stable decrease in NOx, a gas turbine combustor is supplied which can reduce combustion vibration. A combustor (3) is provided with a first box body (30), which is installed outside an object body (20) such as a combustor basket (6), a transition piece (7) or a bypass duct (11) so as to form a first internal space (31) having a predetermined capacity; and a first throat (32) having a predetermined length which has one end (32a) open to a side wall (20a) of the object body (20) and has the other end (32b) open to a first internal space (31); wherein, a first resistive element (33) having a multiple number of through-holes is inserted and engaged to one end (32a). Fluid particles serving as vibration elements of combustion vibration caused in a combustion region are effectively trapped by the first resistive element (33) and at the same time resonate with the air of the first internal space (31) being connected through the first throat (32) and vibrate in the neighborhood of the first resistive element (33), thereby damping vibration amplitude thereof.