Gas Turbine Rotor Sealing Assembly Gap Mitigation

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Solution Overview

Problem

Existing gas turbine rotor sealing designs suffer from gaps between sealing plates, allowing cooling air to escape and reducing the effectiveness of the sealing mechanism, despite the use of overlapping plates and closing elements.

Innovation Solution

The implementation of a closing element that is fastened to the engagement sections of the cover elements, extending in sections along the circumferential direction to cover the assembly space between the cover elements adjacent to the sealing surface, ensuring the space is sealed when the rotor rotates, and utilizing adjustable and overlapping tab elements to enhance sealing without complicating the assembly process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If sealing plates are designed to overlap and be displaceable for assembly, then ease of assembly is improved, but sealing performance deteriorates due to gaps remaining between plates

Engineering Contradiction:
Improveease of assemblyVSAvoidsealing performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A closing element is introduced as an intermediary component between the sealing plates to seal the assembly space. The closing element has a closing section that abuts against the sealing surface and extends into the assembly space, while a connecting section links it to the sealing plates. This mediator fills the gap between overlapping plates without complicating the assembly process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If closing elements are added to seal the assembly space, then sealing performance is improved, but device complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The closing element is merged with the existing sealing plate structure. The connecting section of the closing element connects to the sealing plates, integrating the closing function into the existing assembly rather than adding completely separate components. This reduces the increase in device complexity while maintaining improved sealing performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The closing element serves multiple functions: it seals the assembly space, connects the sealing plates, and maintains structural integrity. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving improved sealing.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If tab elements are made adjustable and overlapping, then sealing effectiveness is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvesealing effectivenessVSAvoidalignment precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The tab elements are designed to be displaceable relative to each other in the circumferential direction, allowing dynamic adjustment during assembly and operation. This displacability compensates for manufacturing tolerances and ensures proper alignment without requiring extremely high manufacturing precision, while still achieving effective sealing.

Inventive Principle:
Principle #15Dynamics

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 solution effectively reduces the leakage of cooling air by ensuring the assembly space is sealed, improving the overall tightness of the sealing mechanism without increasing installation complexity or costs, and can cover multiple assembly spaces with fewer closing elements.

Implementation Method 1

The closing element (21) is arranged on the side pointing towards the rotor axis below the inner engaging portions (12), at least when the rotor (1) rotates

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3561234B1Rotor with sealing assambly
Publication Date: 2020.10.07 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP3561234B1 patent drawingFigure 1
  • EP3561234B1 patent drawingFigure 2
  • EP3561234B1 patent drawingFigure 3~4

AI summary

The rotor of a gas turbine has a rotor disk (01) which has a plurality of circumferentially distributed blade retaining grooves (02) axially penetrating the rotor disk (01), wherein a circumferential annular groove (07) opening radially outwards is arranged in the rotor disk (01) or in a rotor component (06) adjacent to the rotor disk (01), the flank (07) of which extends circumferentially and radially forms a sealing surface (08). The rotor further comprises at least a first cover element (11a, 41) which (11a, 41) engages in the annular groove (07) with a first inner engagement section (12a, 42) and bears against the sealing surface (08) and at least a second cover element (11b) which (11b) engages in the annular groove (07) adjacent to the first cover element (11a) with a second inner engagement section (12b) and bears against the sealing surface (08).Between the two engagement sections (12a, 12b, 42) there is an inner assembly space (09) adjacent to the sealing surface (08). A closing element (21, 51), which is attached (21, 51) to the first inner engagement section (12a, 42) and bears against the second inner engagement section (12b) at least when the rotor is rotating, closes the inner assembly space (09).