Combustion Chamber Shingle Collar Air Guidance
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Solution Overview
Problem
Existing combustion chamber shingles in gas turbine engines face challenges in efficiently guiding cooling air to the hot side, leading to inadequate protection against high temperatures and increased NOx emissions, with complex configurations that complicate precise positioning and manufacturing.
Innovation Solution
A combustion chamber assembly featuring a collar with a protruding first collar portion on the outer side of the combustion chamber wall, which directs air into a mixing air hole, and a cooling air duct with inclined cooling air openings on the inner surface, allowing additional cooling air to flow towards the hot side of the shingle, while a second collar portion ensures airflow direction and reduces backflow, and additive manufacturing simplifies production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a collar with protruding portion is provided on the combustion chamber shingle to guide air into the mixing air hole, then air guidance into the combustion space is improved, but the positioning precision of the collar within the through hole deteriorates
Solution Approach 1:
A positioning element is introduced as an intermediary component between the collar and the through hole. This positioning element fits into a positioning opening in the combustion chamber wall and engages with a corresponding positioning protrusion on the collar, serving as a mediator that ensures precise alignment and positioning of the collar without requiring high precision in the collar manufacturing itself.
Solution Approach 2:
The design changes the positioning mechanism from relying on precise dimensional parameters of the collar to relying on the geometric relationship between the positioning element, positioning opening, and positioning protrusion. This parameter change allows for easier manufacturing of the collar while maintaining precise positioning through the engagement geometry.
2Temperature
If cooling air openings are provided on the inner circumferential surface of the duct portion, then cooling efficiency on the hot side is improved, but the device complexity increases
Solution Approach 1:
The inner circumferential surface of the duct portion is designed to serve multiple functions: it acts as a structural component of the mixing air hole passage and simultaneously provides mounting locations for cooling air openings. This multi-functionality allows cooling to be achieved without adding separate complex cooling structures, as the existing duct portion geometry is utilized for both air mixing and cooling air delivery.
Solution Approach 2:
The cooling air delivery system is merged with the mixing air hole structure. The cooling air openings are integrated into the inner circumferential surface of the duct portion, combining the cooling function with the existing air passage structure. This merging eliminates the need for separate cooling channels or components, reducing overall device complexity while achieving effective cooling.
3Duration of action of stationary object
If a ceramic protective layer is applied to the combustion chamber shingle, then service life against high temperatures is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The combustion chamber shingle design incorporates self-cooling features where cooling air is delivered directly to the hot side surface through openings in the duct portion. This self-service cooling mechanism allows the shingle to regulate its own temperature without requiring thick ceramic protective layers, reducing manufacturing complexity while maintaining service life through active thermal management.
Solution Approach 2:
The design replaces reliance on passive ceramic protective layers with an active cooling system that uses fluid (cooling air) to manage heat. This substitution from a mechanical/structural protection approach (ceramic coating) to a thermal management approach (active cooling) reduces manufacturing complexity while maintaining or improving service life under high temperature conditions.
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 configuration enhances cooling efficiency on the hot side of the combustion chamber shingle, improves air supply to the combustion space, and facilitates precise positioning and manufacturing, thereby extending the service life of the shingles and reducing NOx emissions.
Implementation Method 1
Via said cooling air duct, cooling air can be guided out of the mixing air hole in the direction of a hot side of the combustion chamber shingle facing the combustion space
Implementation Method 2
Air for cooling and for leaning the combustion and therefore for reducing the NOx emissions can be conducted into the combustion chamber via the combustion chamber shingles
Data Source
AI summary
A combustion chamber assembly includes a through hole on the combustion chamber wall bounded on an outer side of the wall by a hole edge and a combustion chamber shingle having a collar bounding a mixing air hole on the outer side of the wall and protruding with a first collar portion beyond the hole edge on the outer side of the wall. A cooling air opening is formed on an inner circumferential surface of a duct portion of the mixing air hole adjoining the first collar portion and extending in the direction of a combustion space, the cooling air opening leading into a cooling air duct which extends through the duct portion and via which cooling air is guided out of the mixing air hole in a direction of a hot side of the shingle facing the combustion space.