Gas Turbine Vane Carrier Thermal Distortion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing gas turbine vane carriers experience radial distortion due to thermal stresses caused by temperature gradients between the upstream portion in contact with the combustor plenum and the downstream portion, leading to mechanical stress and potential failure.
Innovation Solution
A gas turbine vane carrier design with a mechanically separated front ring made of low thermal expansion material, coupled to the upstream end of the casing via a circumferential rail coupling, allowing independent deformation and reducing distortion by decoupling the hot and cold portions, with axial supports to maintain assembly integrity and optional cooling features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the vane carrier casing is made as a single integral structure, then the manufacturing and assembly are simplified, but thermal distortion occurs due to temperature gradients between upstream and downstream portions
Solution Approach 1:
The vane carrier casing is divided into multiple axial sections (first axial section, second axial section, etc.) that can be manufactured separately and then assembled. This segmentation allows each section to be produced with controlled dimensions while accommodating thermal expansion differences, thereby reducing overall thermal distortion of the complete structure.
2Productivity
If the upstream portion of the vane carrier is exposed to high temperature combustor plenum, then the turbine can operate at high temperatures for efficient power generation, but thermal stresses cause radial distortion and mechanical stress
Solution Approach 1:
By segmenting the casing into axial sections with expansion joints between them, the structure can accommodate thermal expansion in the upstream high-temperature zone without transmitting excessive thermal stress to downstream sections, maintaining structural integrity during high-temperature operation.
Solution Approach 2:
The expansion joints introduce flexibility to the structure, allowing it to adapt its dimensional parameters (expansion/contraction) in response to temperature changes. This parameter adaptation enables the turbine to operate efficiently at high temperatures while preventing structural failure from thermal stresses.
3Manufacturing precision
If different materials are used for upstream and downstream sections to accommodate thermal expansion, then thermal distortion is reduced, but the device complexity increases
Solution Approach 1:
The casing is segmented into multiple axial sections that can be constructed from different materials optimized for their respective temperature zones. The expansion joints between sections provide the necessary flexibility while maintaining dimensional stability, achieving thermal distortion reduction without requiring an overly complex monolithic structure.
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 design effectively reduces thermal distortion and allows better control over clearances and expansion/contraction, enhancing the structural integrity and operational reliability of the gas turbine vane carrier.
Implementation Method 1
the temperature of such portion in higher than the temperature of the remaining parts of the vane carrier. Due to this high temperature gradient the hotter part of the turbine vane carrier tries to expand whereas the colder part tries to contract. This thermal stresses lead to a radial distortion of the turbine vane carrier.
Implementation Method 2
a circumferential front ring centered at the gas turbine axis and coupled to the upstream end of the casing... made of low thermal expansion material
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Gas turbine for power plants, the gas turbine (1) having an axis (7) and comprising a compressor (2), a combustor (3) and a turbine (5); the turbine (5) comprising an inner rotor (4) provided with a plurality of blades (6) and an outer vane carrier (9) provided with a plurality of vanes (8) axially interposed between the blades (6); the vane carrier (9) comprising a casing (10) having an upstream end (11); the vane carrier (9) moreover comprising a circumferential front ring (13) centered at the axis (7) and coupled to the upstream end (11) of the casing (10) by a circumferential rail coupling (14).