Gas Turbine Diffuser Segmentation for Shroud Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Centrifugal compressor performance is compromised due to air leakage resulting from shroud distortions caused by asymmetric structural loading, which increases impeller tip clearance and reduces engine efficiency.
Innovation Solution
The radial diffuser section is structurally isolated from the axial diffuser section through a compliant seal and arcuate wall design, allowing relative motion and minimizing the transfer of structural distortions, while maintaining air sealing and alignment with the impeller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the shroud is rigidly mounted to the diffuser assembly, then structural strength is improved, but shroud distortion increases under asymmetric loading
Solution Approach 1:
The diffuser assembly is divided into separate sections (radial diffuser section and axial diffuser section) that can move independently relative to each other, allowing the shroud to remain stable while the diffuser sections accommodate structural distortions
Solution Approach 2:
A flexible seal is used between the radial and axial diffuser sections, allowing relative motion between these sections while maintaining sealing, thus accommodating shroud distortion without compromising structural integrity
2Productivity
If the impeller tip clearance is minimized, then compressor capacity is improved, but air leakage increases under carcass distortion
Solution Approach 1:
The diffuser assembly is segmented into independent sections that can move relative to each other, allowing the shroud to maintain optimal impeller tip clearance while the diffuser sections accommodate structural distortions, preventing air leakage
Solution Approach 2:
The seal between diffuser sections is designed to allow dynamic relative motion between the radial and axial sections, enabling the system to adapt to carcass distortion while maintaining sealing and preventing air leakage
3Use of energy by moving object
If the shroud clearance is reduced for optimal performance, then engine efficiency is improved, but shroud stability deteriorates under extreme loading
Solution Approach 1:
The diffuser assembly is divided into separate radial and axial sections that can move independently, allowing the shroud to maintain optimal clearance for efficiency while the segmented structure accommodates extreme loading conditions
Solution Approach 2:
A flexible seal is employed between diffuser sections, providing the necessary compliance to maintain shroud stability under extreme loading while allowing the clearance to remain optimized for efficiency
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 reduces air leakage and improves impeller tip clearance control, enhancing compressor performance and robustness by decoupling the radial diffuser from structural load paths and allowing for optimized aero performance.
Implementation Method 1
A gas seal is coupled between the second wall and a wall of the near-axial diffuser, the gas seal configured to prevent the compressed air from passing through the seal
Implementation Method 2
The radial diffuser section is structurally isolated from the axial diffuser section through a compliant seal and arcuate wall design, allowing relative motion and minimizing the transfer of structural distortions
Data Source
AI summary
A gas turbine engine includes a compressor assembly that is rotationally coupled to a shaft. The engine includes a radial diffuser assembly coupled to a shroud of the compressor assembly and positioned to receive compressed air from a centrifugal impeller. The radial diffuser assembly includes a first arcuate wall and a second wall, and a near axial diffuser coupled to the radial diffuser assembly and positioned to receive the compressed air from the radial diffuser assembly. The gas turbine includes a gas seal coupled between the second wall and a wall of the near axial diffuser, the gas seal configured to prevent the compressed air from passing through the seal while allowing relative motion between the radial diffuser assembly and the near axial diffuser.