Gas Turbine Burner Front Panel Acoustic Damper Design
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Solution Overview
Problem
Gas turbine burners experience unstable combustion dynamics leading to acoustic pressure oscillations, which can cause equipment damage and operational issues, and existing acoustic dampers face challenges with cooling air velocity affecting their effectiveness and integrity.
Innovation Solution
The design includes a front panel with a dampening chamber and caps that reduce the velocity of cooling air, preventing hot combustion gases from entering the acoustic damper, while allowing acoustic oscillations to be dampened, using a configuration that optimizes the shape and positioning of cooling air inlets, outlets, and caps within the acoustic damper.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the flow of compressed cooling air enters the acoustic damper at a high velocity, then the pressure within the acoustic damper decreases, but hot combustion gases flow into the acoustic damper causing potential damage
Solution Approach 1:
A seal member is introduced as an intermediary component between the cooling air inlet and the acoustic damper chamber. This seal member prevents hot combustion gases from entering the acoustic damper while allowing cooling air to flow through, thus mediating the interaction between the cooling air flow and the acoustic damper internal environment
2Reliability
If the flow of cooling air is at a low velocity, then hot combustion gases are prevented from entering the acoustic damper, but cooling may be ineffective within the acoustic damper
Solution Approach 1:
The seal member is positioned specifically at the cooling air inlet region where it locally modifies the flow characteristics. It allows cooling air to pass through while blocking hot gases, creating different flow conditions in different regions - high velocity cooling air flow for effective cooling, and blocked region for preventing hot gas ingestion
3Stability of the object's composition
If the acoustic damper is exposed to acoustic pressure oscillations, then combustion stability is maintained, but equipment damage or operational problems may occur over time
Solution Approach 1:
The seal member is installed beforehand to protect the acoustic damper from hot gas exposure. This preventive measure cushions the acoustic damper against thermal damage before it can occur, allowing the acoustic damper to withstand acoustic pressure oscillations without suffering from hot gas-induced degradation over time
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 solution effectively reduces acoustic oscillations and prevents damage to the acoustic damper by controlling cooling air velocity, enhancing the reliability of the burner and rotary machine by minimizing the ingestion of hot gases.
Implementation Method 1
at least one acoustic damper that absorbs the acoustic pressure oscillations and that reduces the amplitude of the pressure oscillations
Implementation Method 2
a flow of compressed cooling air is channeled into the acoustic damper
Data Source
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AI summary
An acoustic damper (100) for a rotary machine (10) includes at least one wall (104), at least one cooling air inlet (120 and 122), at least one outlet (102), and at least one cap (128 and 130). The at least one wall (104) extends from a back side (96) of a burner (24) front panel (90) such that the at least one wall (104) partially defines a dampening chamber (106). The at least one cooling air inlet (120 and 122) is defined within the back side (96) of the front panel (90) and is configured to channel a flow of cooling air (124) into the dampening chamber (106). The at least one outlet (102) is defined within the back side (96) of the front panel (90) and is configured to channel the flow of cooling air (124) out of the dampening chamber (106). The at least one cap (128 and 130) is positioned at least partially over the at least one cooling air inlet (120 and 122) and is configured to reduce a velocity of the flow of cooling air (124) within the dampening chamber (106).