Split Cover Plate Turbine Disc Assembly Thermal Management

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Solution Overview

Problem

The operating efficiency of gas turbine engines is limited by material behavior at elevated temperatures, affecting mechanical strength and longevity of turbine components, which existing cooling methods and cover plate designs struggle to optimize effectively.

Innovation Solution

A novel turbine disc assembly with a split cover plate design, comprising radially inner and outer components made from different materials, allowing for relative axial and radial movement, and optimized sealing to manage thermal and centrifugal loads, with coolant transfer holes for efficient cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single cover plate is used to shield the turbine disc, then the disc is protected from hot gases, but the material cost and manufacturing complexity increase due to the need for high-temperature resistant materials across the entire plate

Engineering Contradiction:
Improveprotection from hot gasesVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cover plate is divided into two separate components: an inner annular disc component and an outer annular disc component. The inner component is positioned closer to the combustor and the outer component is positioned farther away. This segmentation allows each component to be manufactured from materials optimized for its specific thermal environment, reducing overall material cost and manufacturing complexity while maintaining protection effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different materials are selected for the inner and outer annular disc components based on their local thermal conditions. The inner component, exposed to higher temperatures, uses materials with appropriate high-temperature properties, while the outer component uses materials optimized for its lower temperature environment. This local quality approach optimizes material selection for each region's specific requirements.

Inventive Principle:
Principle #3Local quality

2Reliability

If a single cover plate is used to shield the turbine disc, then the disc is protected from hot gases, but the weight of the assembly increases

Engineering Contradiction:
Improveprotection from hot gasesVSAvoidweight of cover plate assembly
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The cover plate is divided into two separate components: an inner annular disc component and an outer annular disc component. The inner component is positioned closer to the combustor and the outer component is positioned farther away. This segmentation allows each component to be manufactured from materials optimized for its specific thermal environment, reducing overall material cost and manufacturing complexity while maintaining protection effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different materials are selected for the inner and outer annular disc components based on their local thermal conditions. The inner component, exposed to higher temperatures, uses materials with appropriate high-temperature properties, while the outer component uses materials optimized for its lower temperature environment. This local quality approach optimizes material selection for each region's specific requirements.

Inventive Principle:
Principle #3Local quality

3Temperature

If coolant is directed radially outwardly through a single cover plate, then cooling is provided to the disc, but the sealing complexity increases to prevent hot gas ingress

Engineering Contradiction:
Improvecooling of discVSAvoidsealing complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The cover plate is divided into two separate components: an inner annular disc component and an outer annular disc component. The inner component is positioned closer to the combustor and the outer component is positioned farther away. This segmentation allows each component to be manufactured from materials optimized for its specific thermal environment, reducing overall material cost and manufacturing complexity while maintaining protection effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A seal plate is introduced as an intermediary component between the inner and outer annular disc components. The seal plate includes a seal element that prevents hot gas ingress into the cooling passage while allowing coolant to flow radially outwardly. This intermediary sealing mechanism simplifies the overall sealing design compared to attempting to seal a single large cover plate.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 engine performance and life by reducing material costs, weight, and manufacturing complexity, while improving thermal management and stress distribution across the disc components.

Implementation Method 1

coolant transfer holes in the radially outer annular disc component for cooling the disc

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

coolant transfer holes in the radially outer annular disc component for cooling the disc

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

The radially inner component shields a radially inner extent of the disc from hot coolant

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 4

A seal plate is provided with a seal element to prevent hot gas ingress into a cooling passage

Methodology Applied
Scientific EffectSealing:

Data Source

PatentEP3130752B1Turbine disc assembly
Publication Date: 2019.12.25 ROLLS ROYCE PLC
  • EP3130752B1 patent drawingFigure 1
  • EP3130752B1 patent drawingFigure 2
  • EP3130752B1 patent drawingFigure 3

AI summary

A turbine disc assembly comprises a turbine disc (20) mounted coaxially on a shaft (30) and, in use, arranged in the path of a hot work fluid flow. A cover plate (26, 27) is axially displaced from the turbine disc (20) in a direction upstream with respect to the work fluid flow. The cover plate comprises a radially inner annular disc component (26) and a radially outer annular disc component (27), the annular disc components are arranged coaxially with each other.