Gas Turbine Fuel Heating System for Ice Crystal Removal

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Solution Overview

Problem

Gas turbine engines face performance degradation and potential engine stall due to ice crystal formation in fuel lines, which existing heat exchanger systems are slow to address, especially at high altitudes where they may not generate sufficient heat to melt ice crystals promptly.

Innovation Solution

A fuel heating system that utilizes compressed air heated by exhaust gas to rapidly melt ice crystals in the fuel lines, eliminating the need for engine oil heating and reducing wait times for ice removal, incorporating a dual-fluid plate-fin heat exchanger and a mechanically driven fan to enhance heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a heat exchanger using engine oil is used to remove ice crystals, then ice removal function is provided, but the response time is delayed due to oil heating time

Engineering Contradiction:
Improveice removal effectivenessVSAvoidresponse time for ice melting
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system pre-heats fuel using engine oil during normal operation before ice crystal formation occurs. This preliminary heating action ensures that when ice crystals do form, the fuel is already at a temperature that prevents or quickly melts the ice, eliminating the delay associated with heating oil on demand.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heat exchanger continuously transfers heat from engine oil to fuel during engine operation, maintaining a continuous heating action rather than intermittent heating. This continuous thermal energy transfer ensures the fuel temperature remains consistently above the ice crystal formation point, providing uninterrupted ice prevention.

Inventive Principle:
Principle #20Continuity of useful action

2Reliability

If a heat exchanger using engine oil is used to remove ice crystals, then ice removal function is provided, but at high altitude conditions adequate heat cannot be extracted to melt the ice

Engineering Contradiction:
Improveice removal effectivenessVSAvoidheat transfer capability at high altitude
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The system maintains fuel temperature above freezing point through continuous pre-heating during normal operation, preventing ice crystal formation before high altitude conditions are encountered. This preliminary thermal preparation ensures the fuel is already in a liquid state when altitude changes occur, eliminating the problem of insufficient heat extraction at high altitudes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The engine oil serves dual purposes: it cools engine bearings and simultaneously heats the fuel to prevent ice crystal formation. This self-service approach uses the oil's thermal energy that would otherwise be wasted, creating a self-sustaining thermal management system that operates effectively across varying altitude conditions without requiring additional energy input.

Inventive Principle:
Principle #25Self-service

3Reliability

If last-chance screens are used to remove ice crystals, then ice crystal removal is provided, but the screens must be periodically cleared to prevent blockage

Engineering Contradiction:
Improveice crystal removalVSAvoidmaintenance requirement for screen clearing
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system extracts and removes ice crystals from the fuel through continuous thermal processing in the heat exchanger, preventing them from reaching the last-chance screens. By taking out the ice crystal removal function upstream through heating, the screens remain clear and do not require periodic manual clearing, eliminating the maintenance burden.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The heat exchanger performs preliminary ice crystal removal through continuous heating before the fuel reaches the last-chance screens. This preliminary action prevents ice crystals from accumulating on the screens, thereby eliminating the need for periodic screen clearing and maintenance interventions.

Inventive Principle:
Principle #10Preliminary action

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 ensures immediate and efficient melting of ice crystals, preventing blockages and enhancing engine performance and safety by utilizing readily available heat from exhaust gases, thus improving operational efficiency and reliability.

Implementation Method 1

A fuel heating system that utilizes compressed air heated by exhaust gas to rapidly melt ice crystals in the fuel lines

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

incorporating a dual-fluid plate-fin heat exchanger and a mechanically driven fan to enhance heat transfer

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

incorporating a dual-fluid plate-fin heat exchanger and a mechanically driven fan to enhance heat transfer

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2823170B1Gas turbine engine fuel heating system
Publication Date: 2019.05.01 HAMILTON SUNDSTRAND CORP
  • EP2823170B1 patent drawingFigure 1

AI summary

A fuel heating system for a gas turbine engine comprises a first heat exchanger, a second heat exchanger, a fuel pump and a valve. The first heat exchanger produces a heated air flow. The second heat exchanger receives the heated air flow from the first heat exchanger. The fuel pump provides a fuel flow. The valve is coupled to the fuel pump to intermittently include the second heat exchanger in the fuel flow based on a temperature of the fuel flow. A method of heating fuel in a gas turbine engine comprises providing fuel to a gas turbine engine with a fuel pump to sustain a combustion process, heating a flow of air with exhaust gas from the combustion process, and heating fuel from the fuel pump en route to the gas turbine engine with the flow of air based on a temperature of the fuel.