Centrifugal Compressor Dirt Extraction via Impeller Swirl

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Solution Overview

Problem

The presence of dirt in the gas path and turbine cooling air flow of gas turbine engines leads to reduced durability and performance deterioration, with existing solutions like deflectors and inlet particle separators being ineffective for smaller particles.

Innovation Solution

A centrifugal compressor stage with an extraction scoop and dirt collector is implemented to remove particulates from the primary flowpath, utilizing the impeller's high swirl to centrifuge dirt out and trap it in a plenum, achieving a significant reduction in dirt concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If deflectors are used in the turbine system, then larger particles can be removed, but smaller particles that cause majority of turbine issues remain ineffective

Engineering Contradiction:

Improveparticle removal effectivenessVSAvoidparticle size coverage

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The dirt removal function is segmented into two distinct components: an extraction scoop that removes a portion of the airflow containing particles, and a centrifugal separator that specifically targets and removes smaller particles through centrifugal force. This segmentation allows each component to specialize in different particle size ranges, resolving the contradiction between removing larger particles and effectively capturing smaller particles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A plenum chamber is introduced as an intermediary component between the extraction scoop and the centrifugal separator. The plenum serves as a transition zone that receives airflow from the scoop and directs it to the centrifugal separator, enabling the system to handle both larger and smaller particles effectively while maintaining system versatility.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If inlet particle separators are used, then larger particles can be removed, but smaller particles that tend to cause the majority of turbine issues remain relatively ineffective

Engineering Contradiction:

Improveparticle removal effectivenessVSAvoidturbine durability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The traditional mechanical inlet particle separator is replaced with a centrifugal separation mechanism. Instead of relying on mechanical filtering that is ineffective for small particles, the system uses centrifugal force generated by rotating components to separate particles based on their mass and size, significantly improving the removal of smaller particles that cause turbine durability issues.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The separation mechanism changes from static mechanical filtering to dynamic centrifugal separation. By changing the separation parameter from physical blockage to centrifugal force, the system becomes effective at removing smaller particles while maintaining reliability and turbine durability.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If a centrifugal separator is added to remove smaller particles, then particle removal effectiveness improves, but device complexity increases

Engineering Contradiction:

Improvesmall particle removalVSAvoidcompressor stage structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The centrifugal separator is merged with the existing impeller structure of the compressor stage. The impeller serves dual functions: compressing the airflow and generating centrifugal force for particle separation. This merging eliminates the need for separate centrifugal separation components, reducing device complexity while maintaining effectiveness in removing smaller particles.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The impeller is designed to perform multiple functions simultaneously: it acts as both the compression element and the centrifugal separation element. This multi-functionality reduces the overall number of components needed in the system, thereby reducing device complexity while achieving effective small particle removal.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 results in a 60-90% reduction in dirt in the main airflow, improving turbine durability and performance by preventing dirt accumulation in turbine components and reducing issues like CMAS attack and erosion.

Implementation Method 1

utilizing the impeller's high swirl to centrifuge dirt out and trap it in a plenum

Methodology Applied

Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentUS10267179B2Dirt extraction apparatus for a gas turbine engine

Publication Date: 2019.04.23 GENERAL ELECTRIC CO

AI summary

A centrifugal compressor apparatus includes: an impeller mounted for rotation about a central longitudinal axis, the impeller including an impeller disk carrying an array of impeller blades around its periphery; a diffuser disposed downstream of the impeller, configured to diffuse and turn airflow discharged from the impeller; an extraction scoop disposed in fluid communication with the impeller and with a plenum disposed adjacent the impeller, and a dirt collector disposed in fluid communication with the plenum and configured to trap dirt therein.