Fuel Injector Pintle Dynamics for Gas Turbine Combustion

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Solution Overview

Problem

Gas turbine engines face challenges in controlling fuel spray breakup and quality due to variations in operating conditions, leading to inconsistent combustion processes.

Innovation Solution

A fuel injector system with a mechanically angled pintle and shaped aperture, allowing for independent control of fuel injection based on current conditions, which enhances fuel atomization and reduces variability in fuel spray position and quality across operating ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional fuel injectors with fixed orifices are used, then the structure is simple, but the fuel spray position and quality vary substantially over the operating range

Engineering Contradiction:
Improvefuel spray consistency across operating conditionsVSAvoidfuel injector structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs a movable pintle mechanism that can be positioned at different locations within the injector body, allowing the effective orifice geometry to change dynamically based on operating conditions. This dynamic adjustment capability enables consistent fuel spray characteristics across varying flow rates and pressures, resolving the contradiction between adaptability and structural simplicity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the effective injection parameters (orifice area, shape, and position) by moving the pintle to different locations. This parameter variation allows the fuel injector to maintain optimal spray quality and position across the entire operating range, from idle to full power conditions, thereby improving adaptability without requiring multiple fixed injectors.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the fuel spray breakup mechanisms are allowed to vary with operating conditions, then the injector can adapt to different flows, but the location and quality of fuel spray varies substantially

Engineering Contradiction:
Improvefuel injection efficiencyVSAvoidcombustion control consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control system receives feedback regarding operating conditions (flow rate, pressure, temperature) and automatically adjusts the pintle position to maintain optimal spray characteristics. This closed-loop control ensures consistent combustion performance across varying productivity demands, resolving the contradiction between injection efficiency and combustion control reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system pre-positiones the pintle based on anticipated operating conditions or current sensor data, proactively adjusting the spray parameters before combustion variations occur. This preliminary adjustment maintains reliable combustion control while allowing the system to operate efficiently across different productivity levels.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If a movable pintle mechanism is added to control fuel spray, then fuel atomization consistency is improved, but the device complexity increases

Engineering Contradiction:
Improvefuel spray atomization qualityVSAvoidfuel injector mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention extracts the spray control function from the fixed orifice structure and places it in a separate, movable pintle component. This separation allows the pintle to be independently controlled and optimized for precision spray delivery, while the main injector body remains relatively simple. The modular approach improves atomization quality without proportionally increasing overall device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pintle acts as an intermediary element between the fuel supply and the combustion chamber, mediating the spray characteristics by adjusting its position. This intermediary mechanism provides precise control over fuel atomization quality while keeping the overall injector structure manageable, as the pintle is a single moving component rather than a complex multi-part system.

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

The solution achieves consistent fuel atomization and reduced variability in fuel delivery, improving the operability and efficiency of gas turbine engines by stabilizing fuel injection processes across different operating conditions.

Implementation Method 1

The fuel spray is created by hydrodynamic breakdown of a liquid column of fuel into individual droplets through complex primary and secondary breakup mechanisms

Methodology Applied
Scientific EffectHydrodynamic breakdown: Hydrodynamic Cavitation

Implementation Method 2

These mechanisms depend strongly on the velocities of the liquid and on nearby gas flows. The breakup processes therefore change in location and intensity depending on various operating conditions

Methodology Applied
Scientific EffectAerodynamic interaction: Turbulence

Data Source

PatentEP3671040B1Enhancement for fuel spray breakup
Publication Date: 2022.01.26 RTX CORP
  • EP3671040B1 patent drawingFigure 1
  • EP3671040B1 patent drawingFigure 2
  • EP3671040B1 patent drawingFigure 3~6

AI summary

A combustor (56) or augmentor of a gas turbine engine (20) is provided. The combustor or augmentor includes a wall (410) defining apertures (411) and an interior (412) having an inlet (413), an outlet (414) and a mixing region (415) between the inlet and the outlet and fuel injectors (420). The fuel injectors are respectively arrayed along the wall at corresponding apertures to inject fuel into the mixing region. Each fuel injector includes a fuel injector body (421) defining an injection outlet (423) through which fuel exits the fuel injector body toward the mixing region and a pintle (422). The pintle includes a first end (424), a second end (425) and a pintle body (426) extending between the first and second ends. At least one of the first and second ends is attachable to the fuel injector body to position the pintle body between the injection outlet and the mixing region.