Layered Turbomachinery Seal Assembly for Misalignment Leakage

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Solution Overview

Problem

Turbomachinery components experience leakage due to misalignment and thermal expansion, leading to reduced efficiency and increased NOx production, as existing seals fail to adequately seal gaps between adjacent stator components with varying shapes and temperatures.

Innovation Solution

A seal assembly comprising a permeable wire mesh outer shim and an impervious solid inner shim, coupled via a medial weld, providing flexibility to accommodate misalignment while maintaining stiffness to resist deformation and assembly forces, thus effectively sealing gaps between turbomachinery components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If woven metallic cloth seals with shepherds hook are used, then sealing between stator components is provided, but manufacturing variations and assembly limitations result in inadequate leakage reduction

Engineering Contradiction:
Improvesealing effectivenessVSAvoidseal alignment and fit
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent employs a flexible metallic shim seal that can bend and conform to misaligned surfaces. The seal includes a thin metallic body with a sealing edge that flexes to maintain contact between stator components despite manufacturing variations and thermal expansion, eliminating the need for rigid shepherds hook structures.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the physical parameters of the seal by using a flexible metallic construction with specific thickness and elasticity properties. This allows the seal to adapt its shape and positioning dynamically, compensating for misalignment issues that plague traditional rigid cloth seals.

Inventive Principle:
Principle #35Parameter changes

2Strength

If rigid cloth seals are used, then structural strength is provided, but the seals become crimped or plastically deformed during installation, reducing sealing performance

Engineering Contradiction:
Improveseal structural integrityVSAvoidinstallation flexibility
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The flexible metallic shim seal combines structural integrity with installation flexibility. The thin metallic construction allows the seal to bend and conform during installation without crimping or plastic deformation, while maintaining sufficient strength to withstand operating conditions.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent introduces dynamic flexibility to the seal, allowing it to adapt its shape during installation and operation. The metallic shim can elastically deform to navigate tight spaces and misaligned surfaces, then recover its shape to maintain sealing contact, unlike rigid cloth seals that permanently deform.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If seals are made more flexible to accommodate misalignment, then sealing contact is maintained, but resistance to high forces and temperatures in turbomachinery is reduced

Engineering Contradiction:
Improvemisalignment accommodationVSAvoidtemperature resistance
Core Design Contradiction:
Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent uses a composite metallic construction combining different metal properties or metal treatments to achieve both flexibility and temperature resistance. The seal may incorporate heat-resistant alloys or surface treatments that maintain structural integrity at high temperatures while preserving elastic flexibility for misalignment accommodation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the physical parameters of the metallic seal, including thickness, alloy composition, and heat treatment, to achieve the optimal balance between flexibility and temperature resistance. By carefully controlling these parameters, the seal can flex to accommodate misalignment while withstanding turbomachinery operating conditions.

Inventive Principle:
Principle #35Parameter 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 seal assembly significantly reduces leakage rates by conforming to misaligned components, maintaining sealing contact, and withstanding high temperatures and pressures, enhancing turbomachinery efficiency and component lifespan.

Implementation Method 1

A seal assembly comprising a permeable wire mesh outer shim and an impervious solid inner shim, coupled via a medial weld

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP2977561B1Flexible layered seal for turbomachinery
Publication Date: 2022.04.13 GENERAL ELECTRIC CO
  • EP2977561B1 patent drawingFigure 1
  • EP2977561B1 patent drawingFigure 2
  • EP2977561B1 patent drawingFigure 3~4

AI summary

The present application provides seal assemblies (300) having improved flexibility for reducing leakages between adjacent misaligned components of turbomachinery. The seal assemblies include a first outer shim (302) formed of a flexible permeable material and a second outer shim (304) formed of a substantially impervious material. At least the second outer shim is configured for sealing engagement with seal slots of the adjacent components. The seal assemblies may also include at least one of an inner shim and a filler layer positioned between the first and second outer shims. The seal assemblies may be sufficiently flexible to account for misalignment between the adjacent components, sufficiently stiff to meet assembly requirements, and sufficiently robust to meet operating requirements associated with turbomachinery. A turbomachine including the seal assembly is provided.