Seal Element Internal Fluid Passage for Thermal Stress Relief

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Solution Overview

Problem

Existing seal assemblies in gas turbine engines face high thermal stresses and fatigue due to rubbing friction between stationary and rotating carbon seal elements, which current cooling techniques do not adequately address.

Innovation Solution

A seal assembly for rotational equipment, including a seal land with a groove and aperture, and a seal element with a passage extending to an interface, where a fluid coupling device moves relative to a seal carrier, providing fluid flow through the seal element passage to cool the seal elements and mitigate thermal stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional cooling techniques are used for seal assemblies, then some cooling effect is achieved, but thermal stresses and fatigue from rubbing friction are not adequately addressed

Engineering Contradiction:

Improveseal element temperatureVSAvoidseal element durability under thermal stress

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent employs a fluid delivery system that channels cooling fluid through internal passages within the seal element itself. This hydraulic approach allows direct cooling of the carbon seal element through fluid flow, effectively reducing thermal stresses and improving durability under operating conditions.

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The cooling passages are nested within the seal element structure. The internal passages are integrated into the carbon seal element, allowing the cooling system to be contained within the component itself rather than requiring external cooling mechanisms.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If cooling fluid is delivered to seal elements, then thermal stresses are reduced, but system complexity increases due to fluid delivery mechanisms

Engineering Contradiction:

Improveseal element durabilityVSAvoidfluid delivery system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The seal element incorporates its own internal cooling passages, allowing it to self-cool through the fluid delivery system. The carbon seal element itself serves as the conduit for cooling fluid, eliminating the need for separate external cooling components.

Inventive Principle:

Principle #25Self-service

3Temperature

If internal passages are integrated into seal elements, then cooling efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvecooling efficiencyVSAvoidseal element manufacturing

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent changes the physical parameters of the seal element by incorporating internal passages with specific dimensions and configurations. The passages have controlled cross-sectional areas and routing patterns that optimize cooling efficiency while accommodating manufacturing constraints.

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 solution effectively reduces thermal stresses and degradation of seal elements by cooling them through fluid flow, enhancing the durability and performance of the seal assembly.

Implementation Method 1

fluid delivery to a rotational equipment component... fluid flow through the seal element passage to cool the seal elements

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 2

cooling such a seal assembly... cooling fluid flow through a seal element passage

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3904732B1Rotational equipment seal element with internal fluid passage

Publication Date: 2023.08.16 RTX CORP

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AI summary

An assembly (20) is provided for rotational equipment. This assembly (20) includes a seal land (50) and a seal element (52). The seal land (50) extends circumferentially around and is rotatable about an axial centerline (42). The seal land (50) includes a seal land surface (66). The seal element (52) extends circumferentially around the axial centerline (42). The seal element (52) includes a seal element surface (92) and a seal element passage (100). The seal element surface (92) is abutted against and is sealingly engaged with the seal land surface (66). The seal element passage (100) extends through the seal element (52) to an interface between the seal element surface (92) and the seal land surface (66).