Air Compression Impeller for Turbine Disk Ventilation

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Solution Overview

Problem

Compact gas turbine engines with centrifugal compressors face challenges in providing sufficient ventilation to low-pressure turbine discs due to limited passage sections and pressure drops, especially in engines with smaller radial compressors and specific space constraints.

Innovation Solution

An air compression impeller is integrated downstream of the HP turbine disk, featuring radial fins and a stator partition that guides and compresses air, allowing efficient ventilation of LP turbine discs and simplifying the nozzle structure by eliminating the need for air channelling through blades, while also providing a second ventilation circuit for bearing enclosures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a compact engine with a smaller radial compressor is used, then the engine size is reduced, but the ventilation pressure and passage section for LP turbine discs become insufficient

Engineering Contradiction:
Improveengine sizeVSAvoidventilation pressure
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The invention merges the HP turbine disk with an air compression impeller to form a hybrid component. This combination allows the HP turbine disk to simultaneously perform its original function of extracting energy from hot gases while also compressing ventilation air for the LP turbine discs, thereby maintaining adequate ventilation pressure in a compact engine configuration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The HP turbine disk is given multiple functions: it serves as both the energy extraction component for the HP turbine and as the driving element for the air compression impeller that supplies ventilation air to LP turbine discs. This multi-functionality eliminates the need for separate ventilation systems, enabling compact engine design while maintaining adequate ventilation pressure.

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

2Reliability

If air is channeled through the blades of the distributor, then ventilation is provided, but the nozzle structure becomes complex

Engineering Contradiction:
Improveventilation functionVSAvoidnozzle structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the air compression function from the traditional blade-based distribution system. Instead of channeling air through complex blade passages, the air compression impeller directly compresses and delivers ventilation air to the LP turbine discs, simplifying the nozzle structure while maintaining reliable ventilation.

Inventive Principle:
Principle #2Taking out (Extraction)

3Quantity of substance

If centripetal sampling tubes are used to take air from the HP compressor, then air sampling is achieved, but significant pressure drop occurs

Engineering Contradiction:
Improveair flowVSAvoidpressure drop
Core Design Contradiction:
Quantity of substanceVSStress or pressure

Solution Approach 1:

The invention replaces the passive centripetal sampling tube system with an active air compression impeller that is driven by the HP turbine disk. This mechanical system actively draws in and compresses air from the HP compressor, overcoming pressure losses and ensuring adequate ventilation pressure reaches the LP turbine discs.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 ensures effective ventilation of LP turbine discs and simplifies the nozzle structure, addressing the insufficiency of air supply and space constraints in compact engines, enhancing the overall ventilation efficiency and structural integrity.

Implementation Method 1

The centrifugal impeller of the radial compressor has a relatively large outlet diameter

Methodology Applied
Scientific EffectCentrifugal compression: Centrifugal Force

Implementation Method 2

the partition comprises air guide fins

Methodology Applied
Scientific EffectFluid guidance:

Data Source

PatentEP1785588B1Ventilation device for a turbine disk in a gas turbine engine
Publication Date: 2016.04.13 SAFRAN AIRCRAFT ENGINES SAS
  • EP1785588B1 patent drawingFigure 1
  • EP1785588B1 patent drawingFigure 2
  • EP1785588B1 patent drawingFigure 3

AI summary

The present invention relates to a turbine element ventilation device in a gas turbine engine comprising two mechanically independent turbine rotors, each with at least one turbine disk, respectively a high-pressure (HP) turbine disk (210D) and a low-pressure (LP) turbine disk (231, 232), and a first LP turbine ventilation circuit (F) (230). The device is characterized in that it comprises an air compression impeller (300) disposed downstream of the HP turbine disk, in particular between said HP and LP turbine disks (210, 231), to assist air circulation in said first circuit (F). The invention also relates to the impeller