Gas Turbine Rotor Sealing Ring Overlap for Leakage Reduction

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Solution Overview

Problem

Existing sealing rings in rotors, particularly in gas turbines, suffer from incomplete sealing at the overlap area due to a residual gap that is not fully sealed, leading to leakage, as one section only partially covers one sealing surface and lacks a seal on the other.

Innovation Solution

A sealing ring design with a pressing section and a triangular section that overlap, where the separating surface is oriented opposite to the support surface, allowing both sections to contact the support surface and ensuring a seal, with the pressing section having a larger cross-sectional area to accommodate the triangular section, thus reducing leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sealing ring is designed with overlapping sections to eliminate gaps, then the sealing effectiveness should improve, but a residual gap remains at the overlap area due to one section only partially covering the sealing surface

Engineering Contradiction:
Improvesealing effectivenessVSAvoidoverlap gap elimination
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The sealing ring is divided into multiple sections (first section with first sealing surface, second section with second sealing surface) that overlap with each other. Each section independently seals against rotor components, and the overlap arrangement ensures that even if one section has a gap, the other section provides sealing coverage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the sealing ring are designed with different sealing surface orientations. The first sealing surface is oriented to seal against one rotor component while the second sealing surface is oriented to seal against another rotor component. This local differentiation ensures comprehensive sealing coverage at the overlap area.

Inventive Principle:
Principle #3Local quality

2Volume of moving object

If the cross-section of the sealing ring is made small to reduce rotor diameter, then the rotor size is reduced, but the overlapping sections lack sufficient rigidity

Engineering Contradiction:
Improverotor diameterVSAvoidsection rigidity
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The sealing ring utilizes centrifugal force generated during rotor rotation to press the sealing surfaces against the rotor components. This dynamic sealing mechanism allows the use of smaller cross-sections while maintaining sealing effectiveness, as the sealing force is generated during operation rather than requiring excessive structural rigidity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of relying solely on cross-sectional size for rigidity, the design uses the circumferential overlap arrangement and the radial pressing force from centrifugal action. The sealing effectiveness is achieved through the combination of small cross-section and the dimensional advantage of circumferential overlap with radial sealing force.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 ensures a tighter seal by allowing both the triangular and pressing sections to contact the support surface, significantly reducing leakage in the overlap area and improving the overall sealing efficiency.

Implementation Method 1

the sealing ring, by means of centrifugal force, creates a seal against other rotor components

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3885535B1Sealing ring for a rotor and rotor with such a sealing ring
Publication Date: 2022.09.07 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP3885535B1 patent drawingFigure 1
  • EP3885535B1 patent drawingFigure 2~3
  • EP3885535B1 patent drawingFigure 4~5

AI summary

The invention relates to a sealing ring (01) for use in a gas turbine rotor, wherein sealing is achieved on one side of the sealing ring by means of an approximately radially oriented contact surface (21) and on the other side by a support surface (24) inclined to the rotor axis. The sealing ring is split and has at least one ring segment with a circumferential ring section. At the separation point, a contact section (11) and a triangular section (13) overlap along a parting surface (27). Here, the parting surface (27) intersects the contact surface (21) and enables sealing with both the contact section (11) and the triangular section (13). In order to also enable sealing at the support surface (24) with the contact section (11) and the triangular section (13), the triangular section (13) is reduced to a maximum of 0.3 times the cross-sectional area of ​​the ring section (07).