Compressor Cooling via Longitudinal Passages

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Solution Overview

Problem

Gas turbine engines face a challenge in increasing air mass flow through the compressor without unacceptably reducing the lifetime of components, particularly the compressor rotor disk and blades, due to elevated temperatures at the compressor outlet.

Innovation Solution

The design incorporates longitudinal passages in the compressor rotor blades and drum, utilizing differential pressure to circulate cooling air through these passages, connecting higher and lower pressure areas to enhance cooling, thereby maintaining component longevity at higher temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the air mass flow through the compressor is increased to increase power output, then the power output and efficiency are improved, but the temperature of the compressed air at the compressor outlet increases, causing a large decrease in the lifetime of the compressor rotor disk and blades

Engineering Contradiction:
Improvepower outputVSAvoidlifetime of compressor rotor disk and blades
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The compressor drum is divided into multiple segments along its longitudinal axis, with cooling air supply means provided at different positions (first, second, and third supply means) to cool different sections of the compressor stages. This segmentation allows distributed cooling throughout the high-temperature zones, effectively managing heat stress while maintaining high power output.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Cooling air is introduced as an intermediary substance between the compressed air and the compressor components. The cooling air, supplied at multiple positions along the compressor drum, acts as a thermal buffer that absorbs excess heat from the compressed air and components, preventing temperature-induced lifetime reduction while allowing increased mass flow for higher power output.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If cooling air is injected into the gap between the compressor drum and combustion chamber, then the lifetime of components is extended, but the cooling effectiveness is insufficient to handle higher mass flows and temperatures

Engineering Contradiction:
Improvelifetime of compressor componentsVSAvoidcooling effectiveness
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The single-point cooling approach is segmented into multiple cooling zones along the compressor drum length. Three distinct cooling air supply means are positioned at different longitudinal locations to address thermal stress in various compressor stages, providing distributed and more effective cooling throughout the high-temperature regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling system transitions from a single-dimensional (single location) cooling approach to a multi-dimensional distributed cooling system. Cooling air is supplied at multiple longitudinal positions along the compressor drum, adding spatial distribution as a new dimension to the cooling strategy, thereby significantly improving overall cooling effectiveness for higher mass flow conditions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 allows the compressor to operate at higher temperatures without reducing the lifetime of components, enabling increased power output and efficiency by effectively managing heat stress.

Implementation Method 1

utilizing differential pressure to circulate cooling air through these passages

Methodology Applied
Scientific EffectDifferential pressure: Pressure Gradient

Implementation Method 2

circulate cooling air through these passages

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2418352B1Gas turbine engine comprising a compressor with longitudinal cooling passages
Publication Date: 2019.09.11 ANSALDO ENERGIA SWITZERLAND AG
  • EP2418352B1 patent drawingFigure 1~2
  • EP2418352B1 patent drawingFigure 3~4
  • EP2418352B1 patent drawingFigure 5~6

AI summary

The gas turbine engine comprises a compressor with rotor blades (3) having roots (7) connected into seats (8) of a compressor drum (2). The rotor blade roots (7) and/or the compressor drum (2) have longitudinal passages (9, 10) for a cooling fluid, connecting higher pressure areas (13) to lower pressure areas (14) of the gas turbine engine. The invention also refers to a method for cooling the compressor of a gas turbine engine.