Split Ring Cooling Structure for Gas Turbine Oxidation Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing cooling systems for gas turbines require excessive cooling air, which reduces thermal efficiency and leads to oxidation and thinning of ring segment components.
Innovation Solution
A ring segment cooling system with strategically designed cooling passages, including first, second, and third cooling passages, optimized for convection and film cooling, reduces the amount of cooling air needed while enhancing cooling performance, particularly at corner portions, by utilizing larger cross-sectional areas and pitches for first-region passages and smaller areas/pitches for second-region passages, and incorporating sloped and radial third passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling passages are increased in number and coverage to prevent oxidation and thinning of segment bodies, then cooling performance is improved, but the amount of cooling air required increases, reducing thermal efficiency
Solution Approach 1:
The patent applies different cooling strategies to different regions of the segment body. First-region cooling passages with larger cross-sectional areas are positioned near end portions prone to oxidation, while second-region passages with smaller areas are positioned elsewhere. This localized differentiation optimizes cooling effectiveness where needed most while minimizing overall cooling air consumption, thus preventing oxidation without excessive energy loss.
Solution Approach 2:
The patent varies the cross-sectional area parameter of cooling passages based on their position. First-region cooling passages have larger cross-sectional areas to enhance cooling at vulnerable end portions, while second-region passages have smaller areas. This parameter change allows efficient cooling distribution that prevents oxidation while controlling the total amount of cooling air required, thereby maintaining thermal efficiency.
2Object-affected harmful factors
If cooling air flow is increased to cool end portions of segment bodies, then oxidation resistance is improved, but the quantity of cooling air increases, reducing gas turbine efficiency
Solution Approach 1:
The patent directs cooling air preferentially to end portions of segment bodies where oxidation occurs most frequently by positioning first-region cooling passages with larger cross-sectional areas at these locations. This localized quality enhancement ensures oxidation resistance at critical areas without requiring increased cooling air flow throughout the entire segment body, thus maintaining gas turbine efficiency.
Solution Approach 2:
The patent applies enhanced cooling (larger cross-sectional area passages) only to specific end portions that are most susceptible to oxidation, rather than uniformly increasing cooling throughout the entire segment body. This partial action approach provides sufficient oxidation protection at vulnerable locations while avoiding the excessive cooling air consumption that would reduce gas turbine efficiency.
3Ease of manufacture
If uniform cooling passages are distributed throughout the segment body, then manufacturing is simplified, but cooling effectiveness at critical end portions is insufficient, leading to oxidation and thinning
Solution Approach 1:
The patent differentiates cooling passage design by region: first-region passages with larger cross-sectional areas are positioned at end portions requiring enhanced cooling protection against oxidation, while second-region passages with smaller areas are positioned elsewhere. This local quality differentiation improves reliability at critical locations while maintaining reasonable manufacturing complexity through systematic regional classification.
Solution Approach 2:
The patent segments the cooling passage system into first-region and second-region passages based on their functional requirements. This segmentation allows optimization of cooling effectiveness at critical end portions without requiring complete redesign of the entire cooling system, balancing manufacturing simplicity with targeted cooling effectiveness to prevent oxidation and thinning.
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 effectively prevents oxidation and thinning of segment body components, reduces the overall cooling air requirement, and enhances the thermal efficiency of the gas turbine.
Implementation Method 1
The cooling air CA after the impingement cooling flows from the interior of the main body of the segment body 41 to the upstream and downstream sides of the axial direction of the rotating shaft 5 via the cooling passages 57 and 58, and then performs convection cooling on upstream- and downstream-end portions of the segment body 41
Implementation Method 2
Cooling air CA supplied to the casing blows from the small holes 45 in a downward direction, thereby performing impingement cooling on a surface of a main body (bottom surface) of the segment body 41
Implementation Method 3
a seal plate 53 is inserted into the end portions 51 and 52 in the axial direction of the rotating shaft 5... to prevent the combustion gas FG from leaking from a gap G between the end portions 51 and 52 to the casing
Implementation Method 4
the cooling air CA, which has performed the impingement cooling on the main body of the segment body, is supplied to blow into the combustion gas of the gap G between the end portions 51 and 52 via a cavity 54
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Disclosed is a split ring cooling structure of a gas turbine. The split ring cooling structure is provided with: first cooling channels arranged in the axial direction of the rotating shaft of split bodies; second coaling channels which are arranged in one of the side end sections in the direction nearly orthogonal to the first cooling channels and eject cooling air toward the side end section of the adjacent split body; and third cooling channels which interconnect the cooling space surrounded by the split bodies and a collision plate provided with many small openings and a first cavity arranged in the upstream side end section while being nearly orthogonal to the axial direction of the rotating shaft. The first cooling channels include: cooling channels in a first area which are arranged in proximity to the side end section on the rear side in the direction of the rotation; and cooling channels in a second area which are arranged forward of the cooling channels in the first area in the direction of the rotation. The cooling channels in the second area have smaller cross sectional areas and larger any pitches than the cooling channels in the first area. The cooling channels in the first area are arranged in the proximity of the second cooling channels of the adjacent split body.