Sequential Liner Cooling Holes for Gas Turbine Combustor
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Solution Overview
Problem
In gas turbine combustors, the proximity of adjacent cans hinders cooling air ingress to impingement cooling holes, leading to unstable feeding and low pressure drop, which affects the efficiency and uniformity of cooling, and can result in deformation and reduced lifetime due to uneven temperature distribution.
Innovation Solution
The use of convective cooling holes in sequential liners that direct cooling air into the cooling channel without impinging the inner wall, combined with ribs to enhance stiffness and heat conduction, allows for a more compact design and improved cooling efficiency, enabling closer can placement and reduced deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If impingement cooling holes are used in sequential liners, then cooling effect can be achieved, but cooling air ingress is hindered by proximity of adjacent cans, resulting in unstable feeding and low pressure drop
Solution Approach 1:
Instead of directing cooling air perpendicular to the inner wall as in conventional impingement cooling, the patent inverts the approach by positioning cooling holes on adjacent faces that direct air parallel to the inner wall surface, allowing stable air ingress despite close proximity of adjacent cans
Solution Approach 2:
The patent applies different cooling approaches to different locations: convective cooling holes are positioned on adjacent faces (first and second adjacent faces) while impingement cooling holes are positioned on the first face, allowing each location to use the most effective cooling method for its specific geometric and flow conditions
2Temperature
If impingement cooling is used, then cooling can be provided, but uneven temperature distribution occurs leading to deformation and reduced lifetime
Solution Approach 1:
The patent applies convective cooling on adjacent faces and impingement cooling on the first face, creating a more uniform temperature distribution across the liner by matching the cooling method to the local thermal and flow conditions of each surface
3Temperature
If cooling channel height is increased to accommodate impingement cooling, then impingement cooling can be effective, but the size of non-flowed area between two sequential liners increases
Solution Approach 1:
The patent inverts the conventional approach by using convective cooling (air flowing parallel to the wall) instead of impingement cooling (air directed perpendicular to the wall) on adjacent faces, allowing effective cooling with a much smaller cooling channel height and reducing the non-flowed area between sequential liners
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 provides a more uniform temperature field, reduces deformation, and improves the high-cycle fatigue lifetime of the part by increasing the driving pressure drop and allowing for more compact can placement, while maintaining effective cooling.
Implementation Method 1
each convective cooling hole being arranged to direct a convective cooling flow into the sequential liner cooling channel adjacent to each adjacent face
Implementation Method 2
The rib structure can also improve heat conduction of the sequential liner inner and outer walls
Data Source
Figure 1~2A
Figure 2B~6
Figure 3
AI summary
The invention concerns a sequential liner (10) for a gas turbine combustor, comprising a sequential liner outer wall (12) spaced apart from a sequential liner inner wall (22) to define a sequential liner cooling channel between the sequential liner outer wall (12) and the sequential liner inner wall (22). The sequential liner outer wall (12) comprises a first face (14), a first adjacent face (16) and a second adjacent face (16), the first (16) and second (16) adjacent faces each being adjacent to the first face (14), the first face (14) of the sequential liner outer wall (12) comprising a first convective cooling hole (18) adjacent to the first adjacent face (16) and a second convective cooling hole (18) adjacent to the second adjacent face (16), each convective cooling hole (18) being arranged to direct a convective cooling flow into the sequential liner cooling channel adjacent to each adjacent face (16). The invention also concerns a method of cooling using the sequential liner (10) and a method of retrofitting a gas turbine.