Flex-Fuel Injector Dual Pathways for Gas Turbines

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Solution Overview

Problem

Gas turbine engines face challenges in efficiently mixing fuels with widely different energy densities, such as natural gas and synthetic gas, due to existing swirler assemblies that are optimized for specific fuels, leading to inefficiencies and increased pressure losses when switching between fuels with varying energy densities.

Innovation Solution

The development of a flex-fuel injector design with dual fuel delivery pathways and radial passages that accommodate fuels with dissimilar energy densities, maintaining the existing design aspects for one fuel while enabling efficient operation with lower-energy-density fuels like synthetic gas by adjusting the cross-sectional areas and shapes of the fuel delivery pathways, and using transition areas to reduce turbulence and pressure differentials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a swirler assembly is optimized for natural gas, then natural gas operation efficiency is improved, but operation with synthetic gas becomes inefficient due to widely different energy densities

Engineering Contradiction:
Improvenatural gas operation efficiencyVSAvoidfuel flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The fuel delivery system is segmented into separate pathways: a first fuel delivery pathway for natural gas and a second fuel delivery pathway for synthetic gas. Each pathway has its own swirler assembly with specifically designed cross-sectional areas and shapes optimized for the respective fuel type, allowing independent optimization without compromising the other fuel's performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The injector assembly is designed with multi-functionality to handle both natural gas and synthetic gas efficiently. By incorporating dual fuel delivery pathways with appropriately sized cross-sectional areas, the same injector assembly can switch between different fuel types while maintaining optimal mixing performance for each, thus achieving universality across different fuel applications.

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

2Productivity

If the cross-sectional area of fuel delivery pathways is increased to accommodate lower energy density fuels, then synthetic gas operation improves, but pressure losses increase for higher energy density fuels

Engineering Contradiction:
Improvesynthetic gas operation efficiencyVSAvoidpressure losses
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The fuel delivery system is divided into separate pathways with different cross-sectional areas. The first pathway (for natural gas) has a smaller cross-sectional area optimized for high energy density, while the second pathway (for synthetic gas) has a larger cross-sectional area optimized for low energy density. This segmentation allows each pathway to operate at optimal pressure and flow conditions for its designated fuel type.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the fuel delivery system have different cross-sectional areas tailored to the specific fuel properties. The first fuel delivery pathway has locally optimized dimensions for natural gas, while the second pathway has locally optimized larger dimensions for synthetic gas, ensuring each region provides the appropriate flow characteristics for its intended fuel.

Inventive Principle:
Principle #3Local quality

3Device complexity

If a single fuel delivery pathway is used for both fuels, then device complexity is reduced, but mixing efficiency deteriorates due to inability to optimize for different energy densities

Engineering Contradiction:
Improveinjector structure simplicityVSAvoidmixing efficiency
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The injector assembly is segmented into distinct fuel delivery pathways, each with its own swirler assembly. This segmentation enables precise optimization of mixing characteristics for each fuel type while maintaining a relatively simple overall structure that can be manufactured using standard techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The injector assembly achieves multi-functionality by incorporating dual pathways that can handle different fuel types. Each pathway is designed with universal principles of fluid dynamics to ensure efficient mixing, while the specific cross-sectional areas are tailored to the energy density requirements of each fuel type.

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 allows for efficient operation with fuels of highly different energy densities without compromising the performance of the swirler assembly, maintaining pressure losses and design integrity, and enabling the use of fuels like synthetic gas while maintaining the efficiency of natural gas operation.

Implementation Method 1

The first and second swirler assemblies are configured to mix the first and second fuels with air to form first and second fuel/air mixtures

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

Swirler elements are used to produce a stream of fuel and air in which air and injected fuel are evenly mixed

Methodology Applied
Scientific EffectSwirling flow: Vortex Ring

Implementation Method 3

using transition areas to reduce turbulence and pressure differentials

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP2342494B1Flex-fuel injector for gas turbines
Publication Date: 2017.11.01 SIEMENS ENERGY INC
  • EP2342494B1 patent drawingFigure 1
  • EP2342494B1 patent drawingFigure 2
  • EP2342494B1 patent drawingFigure 3~4

AI summary

A fuel injector (36) for alternate fuels (26A, 26B) with energy densities that differ by at least about a factor of two. Vanes (47B) extend radially from a fuel delivery tube structure (20B) with first and second fuel supply channels (19A, 19B). Each vane has first and second radial passages (21A, 21B) communicating with the respective fuel supply channels, and first and second sets of apertures (23A, 23B) between the respective radial passages and the surface (49) of the vane. The first fuel supply channel, first radial passage, and first apertures form a first fuel delivery pathway providing a first fuel flow rate at a given backpressure. The second fuel supply channel, second radial passage, and second apertures form a second fuel delivery pathway providing a second fuel flow rate that may be at least about twice first fuel flow rate at the given backpressure.