Geared Turbofan Oil Thermal Management Split-Line System

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Solution Overview

Problem

The integration of gear reduction systems in gas turbine engines requires more efficient oil management to cool additional components, while existing systems often overcool oil destined for certain engine locations, reducing overall engine efficiency.

Innovation Solution

A lubricant supply system that directs cooler oil to critical components like fan drive gears and bearings through a split oil management system, with hotter oil directed to other areas, and a valve for selective oil distribution based on need.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a gear reduction system is added to the gas turbine engine, then the fan and low pressure compressor can rotate at different speeds, but additional components require cooling which increases system complexity

Engineering Contradiction:
Improvespeed ratio between fan and compressorVSAvoidcooling system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The lubricant supply system serves multiple functions: it provides lubrication to the gear reduction system, cools the gear components, and manages thermal distribution across different engine sections. By using a single integrated system rather than separate cooling systems for each component, the patent reduces overall system complexity while maintaining the ability to cool multiple components at different temperatures

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

Solution Approach 2:

The system provides different temperature lubricant to different locations based on their specific cooling needs. Cooler lubricant is directed to the gear reduction system components that generate more heat, while warmer lubricant is supplied to other bearing locations. This localized temperature management allows effective cooling of critical components without unnecessarily cooling all engine components, thereby reducing overall system complexity

Inventive Principle:
Principle #3Local quality

2Reliability

If all lubricant is cooled for gear components, then critical components receive optimal cooling, but unnecessary cooling of all oil reduces engine efficiency

Engineering Contradiction:
Improvecooling of critical componentsVSAvoidenergy consumption of cooling system
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The lubricant supply system is divided into separate lines: a first line that supplies cooled lubricant specifically to the gear reduction system, and a second line that supplies warmer lubricant to other bearing locations. This segmentation allows the cooling system to focus energy on cooling only the lubricant that needs it, rather than cooling all lubricant uniformly, thereby improving energy efficiency while maintaining reliable cooling of critical gear components

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different temperature lubricant is supplied to different locations based on their specific thermal requirements. The gear reduction system receives cooler lubricant from the first line where cooling is most needed, while other bearing locations receive warmer lubricant from the second line. This localized temperature management ensures critical components are reliably cooled without wasting energy cooling lubricant that does not require it

Inventive Principle:
Principle #3Local quality

3Reliability

If a split oil management system is implemented, then optimal cooling is provided to critical components, but the system complexity increases with multiple lines and valves

Engineering Contradiction:
Improvelubricant distribution optimizationVSAvoidoil management system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lubricant supply system is segmented into a first line for cooled lubricant to gear components and a second line for warmer lubricant to other bearings. While this creates multiple lines, the segmentation is achieved within the existing lubricant supply infrastructure, allowing optimal cooling distribution without requiring a completely separate complex cooling system for each component

Inventive Principle:
Principle #1Segmentation

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 approach ensures optimal cooling for critical components while maintaining engine efficiency by preventing unnecessary cooling of all oil, thereby improving lubricant distribution and reducing energy consumption.

Implementation Method 1

a fuel/oil cooler that cools a lubricant

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

the at least one other cooler includes an air-to-oil cooler

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

the at least one other cooler also includes an oil-to-oil cooler at which oil from a generator exchanges heat with the oil in the second line

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2809915B1Gas turbine engine with geared turbofan and oil thermal management system
Publication Date: 2019.08.07 UNITED TECH CORP
  • EP2809915B1 patent drawingFigure 1
  • EP2809915B1 patent drawingFigure 2

AI summary

A lubricant supply system for a gas turbine engine has a lubricant lube pump delivering lubricant to an outlet line. The outlet line is split into at least a hot line and into a cool line, with the hot line directed primarily to locations associated with an engine that are not intended to receive cooler lubricant, and the cool line directed through one or more heat exchangers at which lubricant is cooled. The cool line then is routed to a fan drive gear for an associated gas turbine engine. A method and apparatus are disclosed.