Closed Cycle Engine Flow Resistance Absorption

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Solution Overview

Problem

Closed cycle engine systems face significant parasitic power losses due to the energy-intensive process of absorbing carbon dioxide from exhaust gases, which limits their efficiency and working life, as they require compression of exhaust gases to achieve optimal absorption pressure.

Innovation Solution

Incorporating a flow resistance between the exhaust and intake manifolds in the gas circuit to create a pressure difference, allowing for increased absorption efficiency without the need for additional power-consuming components like compressors, and using an adjustable orifice plate or pressure reducing valve to manage pressures within the engine's operating constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If exhaust gas is compressed before absorption to increase CO2 partial pressure, then absorption efficiency is improved, but parasitic power loss increases due to compressor energy consumption

Engineering Contradiction:
Improveabsorption efficiencyVSAvoidparasitic power loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The invention extracts the compression function from a dedicated compressor and integrates it into the exhaust manifold itself, where exhaust gases are compressed by the pressure differential created during engine operation rather than by a separate power-consuming compressor

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses the engine's own exhaust pressure to compress the CO2-rich gases for absorption, eliminating the need for external compression power. The exhaust manifold acts as both a collection point and a compression chamber, utilizing the natural pressure of exhaust gases to achieve the required compression for efficient absorption

Inventive Principle:
Principle #25Self-service

2Productivity

If a flow resistance is added to the gas circuit to create pressure difference, then absorption efficiency is improved through higher absorber pressure, but energy loss is expected to increase

Engineering Contradiction:
Improveabsorption efficiencyVSAvoidenergy loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The invention converts the normally harmful backpressure effect into a beneficial force by using the flow resistance to create a pressure differential that drives CO2 absorption. The resistance that would normally impede exhaust flow is instead utilized to maintain high pressure at the absorber, turning a potential energy loss into a productive force for absorption

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

3Productivity

If intake manifold pressure is increased to improve absorption, then CO2 absorption efficiency increases, but engine peak cylinder pressure increases reducing working life

Engineering Contradiction:
Improveabsorption efficiencyVSAvoidengine working life
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention segments the pressure management function by creating separate pressure zones: high pressure in the exhaust manifold and absorber for efficient CO2 absorption, and controlled lower pressure in the intake manifold to protect engine durability. The flow resistance acts as a pressure buffer, decoupling the pressure requirements of absorption from those of engine intake

Inventive Principle:
Principle #1Segmentation

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 configuration enhances the engine's overall efficiency by increasing absorption efficiency and reducing parasitic losses, allowing for higher export power with the same shaft power and enabling a wider range of engine units to be used, while maintaining control over intake pressures.

Implementation Method 1

an absorber to at least partially absorb the exhaust gases

Methodology Applied
Scientific EffectPhysical absorption: Absorption (physical)

Implementation Method 2

a flow resistance, the flow resistance being located between the absorber and the intake and arranged such that the pressure at the intake is greater than the pressure at the exhaust

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP2032821B1Closed cycle engine
Publication Date: 2010.08.11 BAE SYSTEMS PLC
  • EP2032821B1 patent drawingFigure 1

AI summary

A closed cycle engine system comprises an engine unit operable to combust fuel with combustion supporting gas, and a gas circuit providing fluid communication between the intake and the exhaust of the engine unit. In operation, the engine unit produces exhaust gases. The gas circuit is provided with an absorber to at least partially absorb the exhaust gases and a flow resistance. The flow resistance is located between the absorber and the intake, and is arranged such that the pressure at the intake is less than the pressure at the exhaust. Such an arrangement improves the efficiency of the absorber, and thus the overall efficiency of the engine. A method of operating such an engine system, and vehicles comprising such an engine system, are also disclosed.