Dual-Cycle Hydrogen Engine With Intercooling And Expansion Turbine

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Solution Overview

Problem

There is a need for improvements in gas turbine engine architecture, particularly in the aerospace industry, to enhance efficiency, reduce carbon emissions, and improve power-to-weight ratio, while utilizing hydrogen as a fuel to minimize pollutants.

Innovation Solution

A dual cycle intercooled architecture is introduced, incorporating a heat exchanger to convert liquid hydrogen to gaseous hydrogen, an expansion turbine to extract additional rotational power, and a gaseous hydrogen accumulator and meter to control fuel flow, integrated with a compressor and turbine system to enhance efficiency and power output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a dual cycle intercooled architecture with heat exchanger and expansion turbine is added to convert liquid hydrogen to gaseous hydrogen and extract rotational power, then engine efficiency and power-to-weight ratio are improved, but device complexity increases

Engineering Contradiction:
Improveengine efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The heat exchanger serves multiple functions: it converts liquid hydrogen to gaseous hydrogen, cools the compressed air from the first compressor stage, and preheats the liquid hydrogen using waste heat from the compressed air. The expansion turbine both extracts rotational power to drive the compressor and further expands and cools the hydrogen before combustion. This multi-functionality resolves the contradiction by achieving improved engine efficiency through these combined functions while minimizing the increase in device complexity.

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

Solution Approach 2:

The system changes the physical state and temperature parameters of both the hydrogen and air streams. Liquid hydrogen is converted to gaseous hydrogen through heating in the heat exchanger. Compressed air is cooled by transferring heat to the liquid hydrogen. These parameter changes enable more efficient combustion and improve overall engine efficiency without requiring fundamentally new components, thus managing device complexity.

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If liquid hydrogen is used as fuel with intercooling and expansion turbines, then carbon emissions are reduced, but device complexity increases due to additional components

Engineering Contradiction:
Improvecarbon emissionsVSAvoiddevice complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The system uses the compressed air from the first compressor stage to provide the heat necessary to vaporize the liquid hydrogen and to drive the expansion turbine. The waste heat from compressing air is utilized to heat the liquid hydrogen, eliminating the need for separate heating systems. This self-service approach reduces carbon emissions by enabling complete hydrogen combustion while minimizing device complexity by using existing system components for multiple purposes.

Inventive Principle:
Principle #25Self-service

3Power

If an expansion turbine is added to extract rotational power from expanding hydrogen, then power output is enhanced, but device complexity and initial weight increase

Engineering Contradiction:
Improvepower outputVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The expansion turbine is merged with the existing compressor drive system. The rotational power extracted from the expanding hydrogen in the expansion turbine is combined with the power from the main turbine to drive the compressor. This merging of functions enhances power output while managing device complexity by integrating the expansion turbine into the existing power train rather than adding a completely separate system.

Inventive Principle:
Principle #5Merging (Combining)

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 system improves engine efficiency, reduces carbon emissions, and enhances power-to-weight ratio by utilizing hydrogen fuel with intercooling and expansion turbines, while maintaining a compact design suitable for existing turboprop nacelles.

Implementation Method 1

a heat exchanger to convert liquid hydrogen to gaseous hydrogen

Methodology Applied
Scientific EffectHeat exchanger: Heat Exchanger

Implementation Method 2

a fluid conduit in fluid isolation from the gas conduit and in thermal communication with the gas conduit

Methodology Applied
Scientific EffectThermal communication: Conduction (thermal)

Implementation Method 3

an expansion turbine to extract additional rotational power

Methodology Applied
Scientific EffectExpansion turbine: Turbine

Implementation Method 4

expanding the liquid hydrogen to gaseous hydrogen includes cooling the compressed air from the first stage compressor

Methodology Applied
Scientific EffectAdiabatic cooling: Adiabatic Cooling

Implementation Method 5

a combustor fluidly connected to an outlet of the compressor

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 6

a turbine section fluidly connected to an outlet of the combustor section, the turbine section operatively connected to the compressor to drive the compressor

Methodology Applied
Scientific EffectHeat engine: Heat Engine

Data Source

PatentEP4600471A1Dual cycle intercooled hydrogen engine architecture
Publication Date: 2025.08.13 PRATT & WHITNEY CANADA CORP
  • EP4600471A1 patent drawingFigure 1
  • EP4600471A1 patent drawingFigure 2
  • EP4600471A1 patent drawingFigure 3

AI summary

A gas turbine engine (100) includes a primary gas path (1060 having, in fluid series communication: an air inlet (112), a compressor section (104) fluidly connected to the air inlet, a combustor section (108) fluidly connected to an outlet of the compressor, and a turbine section (116) fluidly connected to an outlet of the combustor section. The gas turbine engine includes a heat exchanger (122) having a gas conduit (126) fluidly connected to the primary gas path, and a fluid conduit (128) in fluid isolation from, and in thermal communication with, the gas conduit. A hydrogen expansion turbine (134) receives hydrogen from the gas conduit of the heat exchanger.