Gas Turbine Combustor Panel Cooling With Seal Ring Pressure Control
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Solution Overview
Problem
The generation of stress concentration at the panel covering the bulkhead in a gas turbine combustor due to thermal expansion differences, and the need for effective cooling of the panel.
Innovation Solution
A combustor design with a panel spaced apart from the swirler and bulkhead by radial and axial gaps, utilizing a seal ring in the axial gap to prevent air leakage and maintain high pressure for effective cooling, where the panel has a lower thermal expansion coefficient than the swirler and bulkhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the bulkhead is covered with a panel to protect it, then the structural integrity is improved, but stress concentration is generated at the panel due to thermal expansion differences
Solution Approach 1:
The patent divides the panel structure into multiple segments with gaps between them, allowing each segment to expand and contract independently due to thermal effects, thereby reducing stress concentration while maintaining overall structural integrity
Solution Approach 2:
The patent changes the physical parameters by creating axial and radial gaps between the panel and the swirler/bulkhead, transforming the rigid continuous structure into a flexible segmented structure that can accommodate thermal expansion differences
2Strength
If the panel is covered to protect the bulkhead, then protection is improved, but the panel requires additional cooling to maintain operational temperature
Solution Approach 1:
The patent introduces cooling air as an intermediary substance that flows through the axial gap between the panel and the bulkhead, absorbing heat from the panel surface and carrying it away, thus cooling the panel without compromising its protective function
Solution Approach 2:
The patent uses pneumatic cooling by directing compressed air through the axial gap to cool the panel surface, utilizing fluid dynamics to transfer heat away from the panel while maintaining the protective covering
3Temperature
If cooling air is supplied to the panel, then cooling effect is improved, but air leakage through the axial gap reduces the pressure and cooling efficiency
Solution Approach 1:
The patent applies local quality by positioning the seal ring specifically at the axial gap region where air leakage occurs, creating a localized seal that prevents leakage while maintaining the overall cooling airflow pattern and pressure distribution
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
Suppresses stress concentration and effectively cools the panel by maintaining high pressure in the cooling air gap, preventing excessive air leakage and ensuring suitable cooling of the panel surface.
Implementation Method 1
the seal ring fitted to the outer peripheral surface of the swirler in the axial gap is in contact with the panel, the cooling air in the axial gap is prevented from leaking through the radial gap to the combustion chamber
Implementation Method 2
the cooling air can be supplied through the cooling air hole of the panel to a surface of the panel which is located in the combustion chamber
Implementation Method 3
when a thermal expansion difference is generated between the bulkhead and the panel, stress concentration may be generated at the panel
Data Source
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AI summary
A combustor of a gas turbine includes: a panel covering a bulkhead from a combustion chamber while being spaced apart from an outer peripheral surface of a swirler by a radial gap and spaced apart from the bulkhead by an axial gap; and a seal ring that is fitted to the outer peripheral surface of the swirler in the axial gap and is in contact with the panel in an axial direction. The bulkhead includes a cooling air hole that is open toward the axial gap. The panel includes a cooling air hole which is located outside the seal ring in a radial direction, is open to the axial gap, and makes the axial gap communicate with the combustion chamber.