Hydrogen G-Cycle Rotary Engine Heat Recovery

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Solution Overview

Problem

Current internal combustion engines face challenges in transitioning to hydrogen fuel due to high NOx emissions, power output reduction, and costly direct hydrogen injection systems, as well as inefficiencies in heat management and friction losses, which affect fuel economy and emissions.

Innovation Solution

A high-efficiency hydrogen G-cycle rotary vane engine that optimizes thermodynamic energy through improved combustion processes, heat transfer cooling, and mechanical systems, including a sodium vapor chamber for heat recovery and an active water cooling system, to enhance power density, reduce NOx emissions, and increase brake thermal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If direct hydrogen injection is used to improve combustion efficiency, then fuel economy is improved, but the system cost increases and injector reliability deteriorates due to high pressure requirements and hydrogen's dryness causing wear

Engineering Contradiction:
Improvefuel economyVSAvoidinjector reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent extracts the injection function from traditional high-pressure injectors and replaces it with a vaporization-based fuel delivery system. Hydrogen is delivered as a vapor-air mixture through port injection, eliminating the need for high-pressure injection hardware and associated reliability issues while maintaining combustion efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical high-pressure injection system with a thermal/vaporization-based system. Instead of using mechanical pressure to deliver hydrogen, the system uses controlled vaporization and natural aspiration to achieve fuel delivery, thereby eliminating mechanical wear and reliability concerns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Object-generated harmful factors

If hydrogen combustion temperature is reduced to lower NOx emissions, then emissions are improved, but power output performance deteriorates

Engineering Contradiction:
ImproveNOx emissionsVSAvoidpower output
Core Design Contradiction:
Object-generated harmful factorsVSPower

Solution Approach 1:

The patent changes the physical state parameter of hydrogen from liquid/gas phase to vapor phase, and modifies the delivery timing and mixture composition. By controlling vaporization temperature and air mixing ratios, the system achieves optimal combustion temperature that balances NOx reduction with power output maintenance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic vaporization cycles and controlled injection timing to regulate combustion characteristics. By adjusting the frequency and duration of vaporization events, the system modulates combustion temperature to simultaneously reduce NOx formation and maintain power output.

Inventive Principle:
Principle #19Periodic action

3Object-generated harmful factors

If heat is removed from the engine to reduce combustion temperature, then emissions are improved, but thermal efficiency deteriorates due to heat loss

Engineering Contradiction:
ImproveemissionsVSAvoidthermal efficiency
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The patent utilizes phase transition of water (liquid to vapor) during combustion to actively control combustion temperature. The vaporization process absorbs excess heat that would otherwise form NOx, while the resulting water vapor contributes to the expansion stroke and maintains thermal efficiency by converting thermal energy into mechanical work.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent converts the harmful effect of excess combustion heat (which causes NOx formation) into a beneficial cooling mechanism through controlled water vaporization. The same thermal energy that would create emissions is instead used to drive phase change and control combustion temperature, turning a harmful factor into a useful control mechanism.

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

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 engine achieves improved fuel economy, reduced emissions, and higher power density by effectively managing heat and friction, with brake thermal efficiency ranging from 65 to 80%, addressing the limitations of existing engines.

Implementation Method 1

A sodium vapor chamber ties or overlaps the multiple chamber reactions together along the combustion/expansion zone. The sodium vapor chamber allows excess heat from the combustion zone to be transfer back into the combustion chambers along the expansion zone.

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

Water from the active cooling system that would normally have no exergy value or ability to perform work is injected back into the engine chamber where it can perform positive exergy work.

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

The G-cycle engine is an automatic, dynamically balanced system that controls and maintains the thermodynamic heat transfer attributes across the combustion/expansion cycle

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

An active water cooling system captures heat from the housing and exhaust and injects it back into the engine cycle.

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP2126314B1Hydrogen g-cycle rotary internal combustion engine
Publication Date: 2019.07.17 PRIME MOVER INT
  • EP2126314B1 patent drawingFigure 1
  • EP2126314B1 patent drawingFigure 2
  • EP2126314B1 patent drawingFigure 3

AI summary

A hydrogen G-cycle rotary vane internal combustion engine has a sodium vapor chamber transferring excess combustion heat into combustion chambers. An active water cooling system captures heat from the engine housing stator, rotor, and sliding vanes and transfers it back into the combustion cycle by premixing it with hydrogen to reduce peak combustion temperature and with an early an late stage combustion chamber injection to help transfer heat from the sodium vapor chamber, to control chamber temperature, and to increase chamber vapor pressure. A combustion chamber sealing system includes axial seals between the rotor and the stator, vane face seals, and toggling split vane seals between the outer perimeters of the sliding vanes and the stator. Sliding vanes reciprocate laterally in and out of the rotor assisted by a vane belting system. A thermal barrier coating minimizes heat transfer and thermal deformation. Solid lubricants provide high temperature lubrication and durability.