Gas Turbine Nozzle Attachment Assembly with Anti-Rotation Block
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Solution Overview
Problem
In gas turbines, existing methods require removal of the upper turbine shell for accessing and replacing nozzle segments, complicating maintenance and testing operations.
Innovation Solution
A turbine nozzle attachment assembly featuring a circumferential groove, an upstanding annular hook with a radially-oriented stem and circumferentially-oriented slot, an anti-rotation block, and an anti-tipping plate that prevent rotation and tipping of nozzle segments, allowing for their removal and replacement without disassembling the upper turbine shell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the upper turbine shell is removed to access nozzle segments, then nozzle segment removal is enabled, but maintenance complexity and downtime increase
Solution Approach 1:
The attachment assembly is divided into separate functional components: the circumferential groove in the turbine component, the upstanding annular hook with slot on the nozzle segment, and the removable anti-rotation block with anti-tipping plate. This segmentation allows the anti-rotation and anti-tipping features to be installed independently without removing the turbine shell, enabling maintenance access while preserving structural integrity.
Solution Approach 2:
The anti-rotation block and anti-tipping plate serve as intermediary elements that mediate between the turbine component and nozzle segment. These intermediaries provide the necessary rotational and tipping constraints while allowing the nozzle segment to be removed and reinstalled through the open end of the circumferential groove without shell removal.
2Reliability
If traditional attachment methods are used, then nozzle segments are securely retained, but rotational and tipping movements cannot be prevented
Solution Approach 1:
The anti-rotation block is preliminarily positioned within the circumferential groove to prevent rotational movement before any tipping can occur. The anti-tipping plate is similarly positioned to preemptively counteract any tipping motion. This preliminary anti-action ensures both rotational and orientation stability are maintained simultaneously throughout operation.
3Stability of the object's composition
If the anti-rotation block is engaged with the upstanding annular hook, then rotational prevention is achieved, but installation complexity increases
Solution Approach 1:
The anti-rotation block is designed to be dynamically positionable within the circumferential groove, allowing it to be easily installed and removed without permanent engagement. The block can be positioned at different locations around the groove circumference, providing rotational stability while maintaining installation simplicity through its movable nature rather than fixed engagement.
Data Source
AI summary
A turbine nozzle attachment assembly includes an outer turbine component (a shroud or a turbine shell) formed with a circumferential groove open in a forward-facing axial direction; a nozzle segment including a vane extending between inner and outer bands, the outer band provided with an upstanding annular hook formed with a hook element extending in an aft-facing axial direction and received in the circumferential groove. The upstanding annular hook and hook element are formed with a circumferentially-oriented slot. An anti-rotation block is located in the circumferentially-oriented slot, and an anti-tipping plate having a circumferential width greater than a corresponding circumferential width of the circumferentially-oriented slot substantially covers a forward face of the anti-rotation block. The anti-rotation block and the anti-tipping plate are fastened directly to the outer turbine component.