Turbine Shroud Assembly with Load Path Forming Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine shroud components experience unevenly distributed mechanical stresses due to high thermal gradients, leading to heat distortion and potential mechanical failures in gas turbines.
Innovation Solution
A turbine shroud assembly design featuring an outer and inner shroud with arcuate portions and load path forming regions that extend into direct contact, creating a loading arrangement with generally evenly distributed radial load forces, minimizing thermal chord effects and stress on the inner shroud.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional turbine shroud design is used, then structural simplicity is maintained, but unevenly distributed mechanical stresses occur due to heat distortion
Solution Approach 1:
The shroud assembly is divided into multiple shrouds (first shroud, second shroud, third shroud) with distinct functional zones. Each shroud segment has specific load-bearing characteristics, allowing differentiated stress distribution across the assembly while maintaining overall structural integrity.
Solution Approach 2:
Different portions of the shroud assembly are designed with varying properties to address local stress concentrations. The arcuate portions and load path forming regions provide enhanced structural characteristics at specific locations where thermal distortion and mechanical stresses are most severe, rather than uniformly strengthening the entire structure.
2Strength
If increased material thickness is used, then stress resistance is improved, but manufacturing cost and weight increase
Solution Approach 1:
Material thickness is optimized locally rather than uniformly increased. The arcuate portions and load path forming regions have enhanced thickness and structural characteristics at specific stress-concentration zones, while other areas maintain minimal necessary thickness, reducing overall weight while providing stress resistance where needed.
Solution Approach 2:
The shroud assembly utilizes composite construction with different materials or material compositions in different regions. This allows optimization of strength-to-weight ratio by selecting materials with appropriate properties for each zone, providing high stress resistance in critical areas without uniformly increasing weight throughout the entire assembly.
3Temperature
If thermal gradients are reduced, then heat distortion is minimized, but thermal chord effects still cause uneven stress distribution
Solution Approach 1:
The shroud assembly is pre-designed with compensatory features including arcuate portions and load path forming regions that anticipate and counteract thermal distortion effects. These structural features are built into the assembly before operation, allowing them to actively compensate for thermal chord effects and maintain uniform stress distribution even when thermal gradients are present.
Solution Approach 2:
The geometric parameters of the shroud assembly, particularly the arcuate portion angles and load path forming region dimensions, are optimized to change the stress distribution characteristics in response to thermal loading. This allows the structure to adapt its mechanical properties under thermal conditions, maintaining uniform stress distribution despite temperature variations.
Data Source
Figure 1
Figure 2~5
Figure 6~8
AI summary
A turbine component includes an outer shroud 14 arranged within a turbine 10 and further including opposed extending portions 16, 18. The component further provides an inner shroud 22 shielding the outer shroud 14 from a gas path within the turbine 10 during operation of the turbine 10 and including opposed arcuate portions 26, 28 extending around and in direct contact with a corresponding extending portion 16, 18 of the outer shroud 14 for supporting the inner shroud 22 from the outer shroud 14. The component further provides a load path forming region 34 at least partially extending between facing surfaces of each arcuate portion 26, 28 and corresponding extending portion 16, 18. During operation of the turbine 10, load path forming regions 34 extend into direct contact between at least a portion of the facing surfaces of each arcuate portion 26, 28 and corresponding extending portion 16, 18, resulting in formation of a loading arrangement 36 having generally evenly distributed radial load forces at the load path forming regions 34.