Variable Displacement Metering Pump for Gas Turbine Fuel Delivery

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Solution Overview

Problem

Gas turbine engines face inefficiencies due to the use of oversized fixed displacement pumps, which waste horsepower and increase fuel heat, leading to potential engine flameouts and reduced fuel absorption of heat sources.

Innovation Solution

A direct metering architecture utilizing a variable displacement metering pump and a separate servo pump, both mechanically driven by an engine shaft via a gearbox, isolates fuel flows to reduce interactions and waste, thereby optimizing fuel delivery and reducing heat addition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a single fixed displacement pump is used for both fuel burn flow and servo flow, then the pump can provide sufficient flow for all functions, but waste horsepower increases and fuel heat rises

Engineering Contradiction:

Improvefuel flowVSAvoidwaste horsepower

Core Design Contradiction:

Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent divides the single pump system into two separate pumps: a metering pump for fuel burn flow and a servo pump for servo flow. This segmentation allows each pump to be sized appropriately for its specific function, eliminating the need for an oversized pump that wastes horsepower while providing both fuel flows.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a variable displacement metering pump that can dynamically adjust its output based on actual fuel burn requirements. This dynamic adjustment capability allows the system to optimize fuel delivery while minimizing energy waste, unlike fixed displacement pumps that operate at constant output regardless of actual needs.

Inventive Principle:

Principle #15Dynamics

2Quantity of substance

If a single fixed displacement pump is used for both fuel burn flow and servo flow, then the pump can provide sufficient flow for all functions, but fuel heat increases reducing cooling capability

Engineering Contradiction:

Improvefuel flowVSAvoidfuel temperature

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

By separating the fuel delivery system into independent metering and servo pump circuits, the patent eliminates unnecessary fuel circulation through by-pass circuits. This reduces unwanted heat transfer to the fuel, maintaining lower fuel temperatures and preserving the fuel's heat absorption capability for engine cooling.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent converts the potential harm of fuel heating into a benefit by optimizing the fuel flow paths. The separated pump system ensures fuel flows only where needed, and the controlled fuel delivery allows the fuel to effectively absorb heat from engine components, turning the fuel's thermal energy into a useful cooling resource.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Quantity of substance

If a single fixed displacement pump is used for both fuel burn flow and servo flow, then the pump can provide sufficient flow for all functions, but engine flameout risk increases

Engineering Contradiction:

Improvefuel flowVSAvoidengine flameout risk

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent separates the metering pump and servo pump into independent systems with isolated fuel circuits. This segmentation ensures that servo pump operations (such as valve actuation) cannot inadvertently draw fuel from the combustor, eliminating the flameout risk associated with single-pump systems while maintaining sufficient fuel supply for both functions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces separate fuel circuits and isolation mechanisms between the metering and servo systems. These intermediary elements prevent direct interaction between the two fuel flows, ensuring that servo operations cannot compromise the fuel burn flow to the combustor, thereby eliminating flameout risks.

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

This solution reduces waste horsepower, minimizes engine flameouts, and improves engine oil cooling by optimizing fuel flow and reducing heat addition to the fuel.

Implementation Method 1

a variable displacement metering pump... metering and delivering precise fuel flow to the combustor

Methodology Applied

Scientific EffectVariable displacement pump mechanism: Pump

Implementation Method 2

a servo pump... providing controlled fuel flow to actuate the metering pump mechanism

Methodology Applied

Scientific EffectHydraulic actuation: Hydraulic Press

Implementation Method 3

both mechanically driven by an engine shaft via a gearbox

Methodology Applied

Scientific EffectGear transmission: Gear

Implementation Method 4

reduces the amount of heat added to fuel which ultimately improves engine oil cooling

Methodology Applied

Scientific EffectThermal absorption: Absorption (physical)

Data Source

PatentUS9574500B2Direct metering using a variable displacement vane pump

Publication Date: 2017.02.21 GENERAL ELECTRIC CO

AI summary

A direct metering architecture is provided having a metering pump and a servo pump wherein the metering and servo pumps are driven by an engine shaft by way of a gearbox transmission. The system reduces wasted horsepower previously occurring with oversized fixed displacement pumps, reduces instances of engine flameout and reduces the amount of heat added to fuel which ultimately improves engine oil cooling.