Multi-Circuit Turbine Lubrication with Segmented Heat Exchangers

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Solution Overview

Problem

Current lubrication systems for turbine engines are not optimized for efficient heat management and lubrication distribution across various components, leading to suboptimal performance and efficiency.

Innovation Solution

A multi-circuit lubrication system with separate lubricant circuits for the gear train and bearings, incorporating lubricant heat exchangers and air valves to regulate lubricant temperature based on component thermal loads, and an optional third lubricant circuit for a generator, enhancing cooling and lubrication efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single lubrication circuit is used for all components, then the device complexity is reduced, but the heat management efficiency deteriorates

Engineering Contradiction:
Improvelubrication system structureVSAvoidlubricant temperature control
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The lubrication system is divided into multiple independent circuits: a first lubrication circuit for the gear train, a second lubrication circuit for the bearings, and optionally a third lubrication circuit for the generator. Each circuit has its own heat exchanger, allowing independent temperature control tailored to the specific thermal requirements of each component group, thereby resolving the contradiction between system simplicity and heat management efficiency.

Inventive Principle:
Principle #1Segmentation

2Temperature

If separate lubrication circuits are used for different components, then the heat management efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvelubricant temperature controlVSAvoidlubrication system structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The lubrication system uses a common lubricant reservoir that serves all multiple circuits, and the circuits can share common components such as the pump and filter. This multi-functional design allows the system to achieve separate temperature control for different components while avoiding the full complexity of completely independent systems, thus balancing heat management efficiency with system simplicity.

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

3Reliability

If lubrication oil is circulated through all components, then the lubrication coverage is improved, but the energy efficiency deteriorates

Engineering Contradiction:
Improvelubrication distributionVSAvoidpump energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The lubrication system segments the oil circulation into separate circuits that target specific component groups (gear train, bearings, generator) with their own dedicated heat exchangers. This segmentation allows the pump to circulate oil only where needed in each circuit, reducing unnecessary energy consumption while ensuring adequate lubrication coverage for each component, thus resolving the contradiction between lubrication coverage and energy efficiency.

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

The system provides improved heat management and lubrication distribution, optimizing the performance of turbine engine components by regulating lubricant temperature according to thermal loads, thereby enhancing engine efficiency and reliability.

Implementation Method 1

a first component lubricated by the first lubricant circuit and comprising a lubricant heat exchanger configured to cool the first lubricant based on a thermal load of the first component

Methodology Applied
Scientific EffectHeat exchanger: Heat Exchanger

Implementation Method 2

a first air valve arranged within the bypass gas path and configured to regulate a flow of air through the lubricant heat exchanger

Methodology Applied
Scientific EffectValve: Valve

Data Source

PatentEP2954185B1Multi-circuit lubrication system for a turbine engine
Publication Date: 2022.05.04 RTX CORP
  • EP2954185B1 patent drawingFigure 1
  • EP2954185B1 patent drawingFigure 2~3
  • EP2954185B1 patent drawingFigure 4

AI summary

A turbine engine system includes a first lubricant circuit, a second lubricant circuit, a plurality of engine stages and a shaft. The first lubricant circuit includes a first turbine engine component that is fluidly coupled with a first lubricant heat exchanger. The first turbine engine component includes a gear train, which connects a first of the engine stages to a second of the engine stages. The second lubricant circuit includes a second turbine engine component that is fluidly coupled with a second lubricant heat exchanger. The second lubricant circuit is fluidly coupled with the first lubricant circuit, and the second turbine engine component includes a bearing. The shaft is supported by the bearing, and connected to one of the engine stages.