Pressure-Regulated Piston Seal for Combustor Liner Rotation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional piston seals in gas turbine engines fail to maintain adequate sealing during takeoff conditions due to relative rotation between the piston ring seal housing and the piston ring, leading to increased leakage and inefficient cooling, which affects turbine efficiency and heat transfer.

Innovation Solution

A pressure-regulated piston seal assembly with a piston ring seal housing and piston ring, featuring arcuate seal ring segments and sectional through-slots or local bumps/channels, ensures sealing engagement regardless of rotation, guiding high-pressure bypass airflow to maintain contact with the combustor liner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional piston seal designs are used, then sealing is maintained under normal conditions, but sealing fails during takeoff conditions due to relative rotation between piston ring seal housing and piston ring

Engineering Contradiction:

Improvesealing reliabilityVSAvoidadaptability to rotation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The piston ring is divided into multiple arcuate seal ring segments that can independently move and rotate relative to each other. This segmentation allows the seal to accommodate relative rotation between the piston ring seal housing and piston ring while maintaining continuous sealing contact with the combustor liner surface.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The seal design transitions from a static rigid structure to a dynamic flexible system where the arcuate segments can dynamically adjust their positions and orientations in response to rotational movements, thermal expansion, and pressure changes, ensuring continuous sealing under varying operating conditions.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the piston ring seal housing is allowed to rotate relative to the piston ring, then adaptability to takeoff conditions is improved, but leakage increases and sealing effectiveness deteriorates

Engineering Contradiction:

Improveadaptability to rotationVSAvoidcompressor air leakage

Core Design Contradiction:

Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The arcuate seal ring segments function as flexible sealing elements that can deform and conform to the combustor liner surface even during relative rotation. This flexibility ensures that the sealing interface remains intact and prevents compressor air leakage while accommodating rotational movements.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The seal design incorporates parameters such as arcuate geometry, segment spacing, and material properties that change in response to operating conditions. These parameter changes allow the seal to maintain optimal sealing performance across different rotation angles and pressure conditions, preventing leakage.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If cooling flow through the piston seal is increased, then cooling effectiveness is improved, but compressor air waste increases

Engineering Contradiction:

Improvecooling effectivenessVSAvoidcompressor air waste

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The arcuate seal ring segments create localized sealing zones that control the distribution of cooling flow. By optimizing the local sealing characteristics at different positions around the combustor liner, the design achieves effective cooling of critical areas while minimizing overall compressor air consumption through precise flow management.

Inventive Principle:

Principle #3Local quality

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 controls leakage and maintains sealing across all flight conditions, including takeoff, by ensuring continuous engagement of the piston ring with the combustor liner, optimizing cooling flow and turbine efficiency.

Implementation Method 1

The piston ring is responsive to a regulated pressure to secure sealing engagement of the piston ring and an outer surface of the combustor liner

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS11221140B2Pressure regulated piston seal for a gas turbine combustor liner

Publication Date: 2022.01.11 GENERAL ELECTRIC CO

AI summary

A seal assembly to seal a gas turbine hot gas path flow at an interface of a combustor liner and a downstream component, such as a stage one turbine nozzle, in a gas turbine. The seal assembly including a piston ring seal housing, defining a cavity, and a piston ring disposed within the cavity. The piston ring disposed circumferentially about the combustor liner. The piston ring is responsive to a regulated pressure to secure sealing engagement of the piston ring and outer surface of the combustor liner. The seal assembly includes at least one of one or more sectional through-slots, bumps or channel features to provide for a flow therethrough of a high-pressure (Phigh) bypass airflow exiting a compressor to the cavity. The high-pressure (Phigh) bypass airflow exerting a radial force on the piston ring.