Compressor Hub Cooling via Tapped Air Heat Exchange

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Solution Overview

Problem

Gas turbine engine compressor designs face challenges in achieving high temperature and pressure at the final compressor stage due to physical limitations, which affect the cooling of the compressor hub and turbine sections.

Innovation Solution

A compressor section design where air is tapped from a radially outer location, cooled in a heat exchanger, and delivered back to a radially inner outlet to cool the hub and turbine sections, reducing temperature by up to 50°F (10°C) and improving rotor life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If air is tapped from a radially outer location and cooled in a heat exchanger, then cooling efficiency is improved and rotor life is extended, but device complexity increases due to additional cooling system components

Engineering Contradiction:
Improverotor lifeVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts air from the compressor outlet and separates it from the main flow path to be cooled independently in a heat exchanger. This extracted air is then returned to cool the rotor hub, allowing effective cooling without interfering with the main compression process and extending rotor life.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The heat exchanger acts as an intermediary component that facilitates heat transfer from the extracted air to the external environment. This mediator enables efficient cooling of the rotor hub by providing a dedicated thermal exchange path separate from the main gas path.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If cooling air is delivered to the hub, then temperature is reduced and rotor life is improved, but weight increases due to additional cooling system components

Engineering Contradiction:
Improvehub temperatureVSAvoidcompressor section weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The cooling system is designed to serve multiple functions: it cools the rotor hub, manages thermal loads in the compressor section, and extends rotor life. By integrating these functions into a unified system that uses existing compressor air, the design avoids additional weight-penalty components while achieving effective temperature reduction.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If air is tapped from radially outer location, then cooling efficiency is improved, but manufacturing precision requirements increase for tap and outlet positioning

Engineering Contradiction:
Improvecooling efficiencyVSAvoidtap and outlet positioning precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention implements localized air extraction at a specific radially outer position in the compressor outlet and delivers cooled air to a specific radially inner position at the hub. This localized approach optimizes cooling efficiency by targeting the hottest regions while using straightforward positioning that does not require excessive manufacturing precision.

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

This design enhances the life of high pressure compressor rotors and turbine blades by reducing temperatures, while also potentially reducing weight and improving cooling efficiency for the gas turbine engine.

Implementation Method 1

cooled in a heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3181869B1Compressor core inner diameter cooling
Publication Date: 2022.01.26 RTX CORP
  • EP3181869B1 patent drawingFigure 1
  • EP3181869B1 patent drawingFigure 2A
  • EP3181869B1 patent drawingFigure 2B

AI summary

A compressor section (100) for use in a gas turbine engine (20) comprises a compressor rotor having a hub (109; 123) and a plurality of blades extending radially outwardly from the hub (109; 123) and an outer housing surrounding an outer periphery of the blades. A tap (104; 116) taps air at a radially outer first location, passing the tapped air through a heat exchanger (106; 118), and returning the tapped air to an outlet (110; 122) at a second location which is radially inward of the first location, to provide cooling air adjacent to the hub (109; 123).