Sealing Device for Gas Turbine Dovetail Gap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sealing devices for gas turbine systems require costly modifications to both the rotor wheel and bucket dovetails, and existing solutions are inefficient in preventing hot gas ingestion, which can lead to component failure.
Innovation Solution
A sealing device with a cover plate and retention member that attaches directly to the dovetail, engaging a retention slot, providing a seal against centrifugal forces without modifying the rotor wheel or bucket assembly, effectively sealing gaps between the dovetail and rotor wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sealing devices are mounted to the rotor wheel, then sealing effectiveness is improved, but manufacturing cost and complexity increase due to special features required on the rotor wheel
Solution Approach 1:
Instead of mounting the sealing device to the rotor wheel as in prior art, the sealing device is inverted to attach directly to the bucket dovetail. This reverses the mounting approach, allowing the sealing function to be achieved without modifying the rotor wheel, thereby reducing manufacturing cost while maintaining sealing effectiveness
Solution Approach 2:
The sealing function is extracted from the rotor wheel assembly and transferred to the bucket dovetail assembly. By removing the dependency on rotor wheel modifications, the solution simplifies the overall system while achieving the same sealing purpose
2Reliability
If sealing devices interface with portions of the bucket that require special manufacturing, then sealing is achieved, but manufacturing cost increases due to unnecessary modifications
Solution Approach 1:
The sealing device is designed to interface with a specific local feature (the retention slot in the dovetail) that can be easily added during standard manufacturing. This localized approach avoids unnecessary modifications to other portions of the bucket assembly, achieving sealing effectiveness while minimizing manufacturing cost
3Reliability
If sealing devices are required to interface with specially manufactured portions of the bucket, then sealing function is achieved, but device complexity increases
Solution Approach 1:
The sealing device is segmented into distinct functional components: a cover plate portion that provides the sealing surface and a retention member portion that provides the attachment feature. This segmentation allows each component to be designed and manufactured independently, simplifying the overall device while achieving both sealing function and ease of manufacture
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 seals gaps between the dovetail and rotor wheel, preventing hot gas ingestion and reducing the risk of component failure, while allowing for retro-fitting to existing systems without additional modifications, thus enhancing operational efficiency and reducing costs.
Implementation Method 1
The sealing device provides a seal against the gap when the bucket assembly is subjected to a centrifugal force
Implementation Method 2
a retention member protruding from the cover plate and configured to engage the dovetail
Data Source
AI summary
A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assembly is subjected to a centrifugal force.