Electrodynamically Suspended Seal for Rotary Machine Leakage

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Solution Overview

Problem

Turbomachines face significant challenges with fluid leakage due to the radial gap between rotating and stationary parts, leading to decreased efficiency and increased maintenance costs, as existing seals wear out quickly and require frequent replacement.

Innovation Solution

The implementation of an electrodynamically suspended seal system, which uses a rotating electrically conducting element and a magnetic element to create a levitation force, counteracted by a counteracting force, to maintain a reduced radial gap without an active control system, thereby reducing fluid leakage and enhancing turbomachine performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional seals are used to reduce fluid leakage, then sealing performance is improved, but seal wear increases and reliability decreases

Engineering Contradiction:

Improvefluid leakageVSAvoidseal wear and lifespan

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent replaces traditional mechanical contact seals with an electrodynamically suspended seal system that uses electromagnetic fields to create a non-contact sealing mechanism. The rotating element with electrically conducting material and the stationary element with magnetic material generate levitation forces that suspend the sealing elements without physical contact, eliminating wear while maintaining sealing effectiveness.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental operating parameter of the seal from mechanical contact to electromagnetic interaction. By controlling the electromagnetic field parameters (current, magnetic strength) the system adjusts the levitation force to maintain optimal separation distance, achieving sealing without contact wear.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If the radial gap between rotating and stationary parts is reduced to improve sealing, then fluid leakage decreases, but the risk of contact and wear increases

Engineering Contradiction:

Improvefluid leakageVSAvoidcontact wear and mechanical damage

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The patent substitutes electromagnetic suspension for mechanical support, allowing the sealing elements to maintain a reduced radial gap without physical contact. The electrodynamic levitation force counteracts the tendency for the elements to contact, enabling tight sealing clearance without the harmful effects of mechanical wear.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies the counteracting force principle by using electromagnetic levitation forces to counterbalance the forces that would otherwise cause the rotating and stationary sealing elements to contact. This creates a stable equilibrium at an optimal separation distance that minimizes leakage while preventing wear.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

3Loss of energy

If active control systems are added to maintain optimal seal clearance, then sealing performance is improved, but device complexity increases

Engineering Contradiction:

Improvefluid leakageVSAvoidcontrol system requirements

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements a self-regulating electrodynamic seal system where the electromagnetic suspension automatically adjusts to maintain optimal clearance. The system uses the rotational motion itself to generate the levitation force, creating a self-sustaining mechanism that adapts to operating conditions without requiring external active control systems.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent creates a dynamically adaptive seal system where the electromagnetic field automatically adjusts to maintain stable separation. The levitation force naturally responds to changes in operating conditions, providing inherent stability without complex control mechanisms.

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 fluid leakage, increases turbomachine efficiency, and decreases maintenance and operational costs by maintaining a stable separation distance between rotating and stationary parts, allowing for improved performance without the need for secondary sealing systems.

Implementation Method 1

The rotational movement of at least one of the first and second elements creates a levitation force such that the first and second elements are repelled away from one another

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS9322478B2Seal system and method for rotary machine

Publication Date: 2016.04.26 GE INFRASTRUCTURE TECH LLC

AI summary

A system includes an electrodynamically suspended seal. The electrodynamically suspended seal includes a first element that includes an electrically conducting material and a second element that includes a magnetic material. At least one of the first and second elements is configured to rotate about an axial axis. The first and second elements are disposed adjacent one another. The rotational movement of at least one of the first and second elements creates a levitation force such that the first and second elements are repelled away from one another. The electrodynamically suspended seal also includes a third element configured to create a counteracting force.