Variable Microchannel Combustor Liner Cooling

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Solution Overview

Problem

Gas turbine combustor liners experience significant thermal stress due to combustion reactions, with existing cooling techniques like impingement cooling being ineffective in uniformly cooling the aft end portion, leading to localized hot spots and reduced cooling efficiency.

Innovation Solution

The implementation of variable microchannels between the inner and outer wall portions of the combustor liner, coupled directly along the length, with an inlet guide to direct coolant airflow axially, preventing impingement cooling and ensuring uniform cooling by accelerating airflow through progressively decreasing cross-sectional areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If impingement cooling is used to cool the combustor liner, then cooling is provided to the liner surface, but localized hot spots occur and cooling uniformity deteriorates

Engineering Contradiction:

Improvecooling effectivenessVSAvoidcooling uniformity

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

The cooling system is segmented into multiple discrete cooling holes arranged in a pattern across the combustor liner surface. Each cooling hole acts as an independent cooling element, allowing distributed cooling throughout the liner rather than concentrated cooling at single points, thereby preventing localized hot spots while maintaining effective cooling.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cooling holes are strategically positioned at specific locations on the combustor liner where thermal stress and heat transfer requirements are highest. This localized cooling approach concentrates cooling resources where they are most needed, improving overall cooling effectiveness while maintaining uniform temperature distribution across the liner surface.

Inventive Principle:

Principle #3Local quality

2Temperature

If cooling holes are provided in the combustor liner, then heat transfer is enhanced, but structural strength may be compromised

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidliner structural strength

Core Design Contradiction:

TemperatureVSStrength

Solution Approach 1:

The combustor liner incorporates a pattern of cooling holes that creates a porous structure. This porous configuration allows effective heat transfer through the liner while the distributed hole pattern maintains structural integrity by avoiding large gaps or concentrations of openings that would compromise strength.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The combustor liner is constructed using composite materials that combine structural integrity with thermal management capabilities. The liner structure integrates cooling holes within a material system designed to maintain strength while enabling effective heat transfer, achieving both cooling efficiency and structural durability.

Inventive Principle:

Principle #40Composite materials

3Temperature

If multiple cooling holes are arranged in a pattern, then cooling coverage is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvecooling coverageVSAvoidmanufacturing complexity

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The cooling system is divided into multiple discrete cooling holes arranged in a repeating pattern. This segmentation allows the complex cooling requirement to be met through simple, replicated units that can be manufactured using standard drilling and machining operations, avoiding the need for complex custom cooling structures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cooling hole pattern serves multiple functions simultaneously: it provides distributed cooling coverage, maintains structural integrity, and facilitates ease of manufacture through standardized geometry. The universal design of identical cooling holes arranged in a regular pattern allows a single manufacturing process to address multiple cooling requirements efficiently.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 thermal stress and enhances cooling uniformity along the combustor liner, preventing hot spots and maintaining effective heat transfer by ensuring a direct and uniform airflow distribution.

Implementation Method 1

Each channel of the multiple channels is configured to direct a coolant along the combustor liner to convectively cool the combustor liner

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 2

each channel of the multiple channels includes a cross-sectional area that progressively changes along a length of each channel

Methodology Applied

Scientific EffectVenturi effect: Venturi Effect

Data Source

PatentUS11859818B2Systems and methods for variable microchannel combustor liner cooling

Publication Date: 2024.01.02 GE INFRASTRUCTURE TECH LLC

AI summary

In accordance with an embodiment of the disclosure, a system includes a combustor liner disposed about a combustion chamber of a combustor of a gas turbine system. The combustor liner includes an inner wall portion exposed to the combustion chamber, an outer wall portion disposed about the inner wall portion, and multiple channels between the inner and outer wall portions of the combustor liner. Each channel of the multiple channels is configured to direct a coolant along the combustor liner to convectively cool the combustor liner, and each channel of the multiple channels includes a cross-sectional area that progressively changes along a length of each channel of the plurality of channels.