Gas Turbine Bleed Air Turbo-Compressor Speed Control

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Solution Overview

Problem

Gas turbine engines face inefficiencies due to pressure variations in the compressor section, making it challenging to match the pneumatic system's demand for airflow and pressure, which affects engine operating efficiency.

Innovation Solution

A control valve and controller system that adjusts airflow through the turbine and exhaust valve to manage airflow excess, ensuring the pneumatic system receives air at optimal pressures and flow rates by utilizing a turbo-compressor and variable speed transmission to match demand, while excess airflow is exhausted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If bleed air is obtained from different locations within the compressor section to match pneumatic system demand, then the adaptability to varying pressure conditions is improved, but the device complexity increases due to multiple bleed air extraction points and control mechanisms

Engineering Contradiction:
Improveadaptability to varying pressure conditionsVSAvoidcomplexity of multiple bleed air extraction points
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The compressor section is divided into multiple stages with separate bleed air extraction points at different locations. Each extraction point can independently supply bleed air to the pneumatic system, allowing the system to adapt to varying pressure demands by selecting appropriate extraction points based on operating conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bleed air system incorporates dynamic control mechanisms that adjust the operation of different bleed air extraction points based on real-time engine operating conditions. Control valves and sensing systems dynamically regulate which extraction points are active and at what flow rates, enabling continuous adaptation to changing pneumatic system demands.

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If bleed air pressure is increased to meet high demand conditions, then the pneumatic system demand is satisfied, but the engine operating efficiency deteriorates due to pressure mismatches

Engineering Contradiction:
Improvebleed air pressureVSAvoidengine operating efficiency
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The system changes operating parameters by selectively activating different bleed air extraction points based on the required pressure and flow conditions. At lower engine power settings, extraction points that provide pressures closely matching demand are selected. At higher power settings, different extraction points are activated to optimize the match between supplied pressure and pneumatic system demand, thereby maintaining engine efficiency across varying operating conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The bleed air system incorporates feedback control mechanisms that continuously monitor pneumatic system demand and engine operating conditions. Based on this feedback, the control system adjusts which bleed air extraction points are active and regulates their flow rates to optimize the match between supplied air pressure and system demand, minimizing energy losses and maintaining engine efficiency.

Inventive Principle:
Principle #23Feedback

3Device complexity

If a fixed bleed air extraction point is used, then the device complexity is reduced, but the ability to match pneumatic system demand under varying engine conditions deteriorates

Engineering Contradiction:
Improvesimplicity of single extraction pointVSAvoidability to match demand under varying conditions
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

Instead of a single fixed extraction point, the compressor section is segmented into multiple extraction points at different stages. Each extraction point is equipped with control mechanisms that can independently regulate bleed air flow, providing the system with multiple options for meeting varying pneumatic demands while maintaining manageable complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bleed air system is designed with multi-functionality by incorporating multiple extraction points that can serve different pneumatic system demands. Each extraction point can function independently or in combination with others, allowing the system to universally handle a wide range of operating conditions and pneumatic system requirements without requiring completely different configurations for each scenario.

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 stabilizes airflow and pressure to the pneumatic system, enhancing engine efficiency by optimizing the operation of the compressor and turbine sections, even under varying engine conditions.

Implementation Method 1

The high-energy exhaust gas flow expands through the turbine section to drive the compressor and the fan section

Methodology Applied
Scientific EffectGas expansion:

Implementation Method 2

A control valve controlling airflow through the turbine for controlling a speed of the turbine

Methodology Applied
Scientific EffectFlow control:

Implementation Method 3

Air entering the compressor section is compressed and delivered into the combustion section

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-energy exhaust gas flow

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3260684B1Gas turbine engine comprising a gearbox between a bleed air system turbine and compressor
Publication Date: 2021.04.21 RTX CORP
  • EP3260684B1 patent drawingFigure 1
  • EP3260684B1 patent drawingFigure 2~3
  • EP3260684B1 patent drawingFigure 4

AI summary

A gas turbine engine (20) includes a main engine compressor section (24). A booster compressor (70) changing a pressure of airflow received from the main engine compressor section (24) to a pressure desired for a pneumatic system (64). The booster compressor (70) operates at airflow conditions greater than a demand by the pneumatic system (64). A speed change system (84) drives the booster compressor (70) at speeds corresponding to a demand of the pneumatic system (64). A bleed air system (62) for a gas turbine engine (20) and a method of controlling engine bleed airflow are also disclosed.