Gas Turbine Nozzle Mounting Assembly Anti-Rotation Design
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Solution Overview
Problem
Gas turbine nozzle assemblies face structural issues such as component cracking and inefficient sealing due to operational stresses, which existing mounting and sealing structures fail to adequately address.
Innovation Solution
A nozzle mounting and sealing assembly featuring a retaining ring with an anti-rotation pin and seal plate, along with a cooling groove, that provides axial alignment and sealing while allowing for slight rotational freedom, reducing thermal stresses and improving sealing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional mounting and sealing structures are used, then the nozzle assembly can be installed, but operational stresses cause component cracking and inefficient sealing
Solution Approach 1:
The seal plate is designed with flexibility to accommodate thermal expansion and rotational movement of the nozzle assembly during operation. The seal plate includes compliance features that allow it to dynamically adapt to stress-induced deformations, maintaining sealing contact without causing component cracking.
Solution Approach 2:
The mounting structure incorporates stress-relief geometry that changes the mechanical parameters of the connection, such as rounded transition radii and tapered interfaces, to reduce stress concentration factors and distribute thermal stresses more uniformly across the nozzle assembly.
2Manufacturing precision
If the nozzle assembly is rigidly fixed to prevent rotation, then positioning accuracy is improved, but thermal stresses increase causing component cracking
Solution Approach 1:
The anti-rotation constraint is segmented into multiple discrete contact points rather than a continuous rigid constraint. The seal plate engages the nozzle outer band at several spaced locations, providing rotational stability while allowing localized thermal deformation without generating excessive stress.
Solution Approach 2:
The seal plate acts as an intermediary element between the rigid retaining ring and the nozzle assembly. It provides the anti-rotation pin slot that constrains rotational movement while its flexible, compliant material properties allow it to accommodate thermal expansion, mediating between the need for positioning precision and stress reduction.
3Stability of the object's composition
If the seal plate is rigidly mounted to the retaining ring, then sealing stability is improved, but thermal expansion causes inefficient sealing
Solution Approach 1:
The seal plate is designed as a thin, flexible component that can elastically deform to maintain sealing contact. It includes flexible diaphragm sections that conform to thermal expansion and movement of the nozzle assembly, ensuring continuous sealing performance despite thermal cycling and dimensional changes.
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
The solution effectively reduces thermally induced stresses and enhances sealing performance, preventing component cracking and ensuring efficient operation of the gas turbine system.
Implementation Method 1
at least one cooling groove disposed within the retaining ring at an interface between the retaining ring and the seal plate
Implementation Method 2
The solution effectively reduces thermally induced stresses
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A nozzle assembly (10) includes a nozzle having a trailing edge of an outer band (14) and an anti-rotation pin slot (40). Also included is a retaining ring (50) extending circumferentially about the outer surface of the outer band, wherein the retaining ring includes an anti-rotation pin (52) and an anti-rotation pin hole (53), wherein the anti-rotation pin is configured to fittingly reside in an axial orientation within the anti-rotation pin slot and the anti-rotation pin hole. Further included is a seal plate (60) seated on the outer surface of the outer band (14) and configured to retain the anti-rotation pin. Yet further included is a washer (90) disposed within a bored portion (80) of the seal plate (60), wherein the bored portion (80) is aligned with an aperture within the retaining ring, wherein a mechanical fastener extends into the retaining ring (50) through the bored portion (80) to operably couple the seal plate to the retaining ring.