Ethanol Engine Reformer Recovery Loop Stabilization

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Solution Overview

Problem

The ethanol engine system faces instability in reformed gas components and calorific value due to varying ethanol concentrations, leading to reduced thermal efficiency and complex control requirements.

Innovation Solution

The system stabilizes reformed gas components by recycling and re-supplying the recovery solution from a recovery tank to both the reformer and combustion chamber, maintaining consistent ethanol concentration and enhancing hydrogen concentration, thereby simplifying control and improving thermal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If aqueous ethanol solution is directly injected into the combustion chamber and reformed gas is supplied to the engine, then thermal efficiency is enhanced through exhaust heat recovery, but ethanol concentration varies causing instability in reformed gas components and calorific value

Engineering Contradiction:
Improveexhaust heat recovery efficiencyVSAvoidethanol concentration stability
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The invention recovers and recycles the aqueous ethanol solution that has passed through the reformer back to the reservoir tank, creating a closed-loop system. This recovery approach maintains ethanol concentration stability while continuing to enable exhaust heat recovery for reforming, thus resolving the contradiction between energy efficiency and composition stability.

Inventive Principle:
Principle #34Discarding and recovering

2Stability of the object's composition

If ethanol concentration is monitored and controlled to maintain stability, then reformed gas components and calorific value are stabilized, but control system complexity increases

Engineering Contradiction:
Improveethanol concentration stabilityVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system achieves self-regulation of ethanol concentration through the recycling mechanism. The aqueous ethanol solution that exits the reformer with reduced ethanol concentration is automatically returned to the reservoir tank, where it mixes with fresh ethanol solution, naturally maintaining concentration stability without requiring external monitoring or control systems.

Inventive Principle:
Principle #25Self-service

3Quantity of substance

If dehydration process is used to concentrate ethanol, then fuel quality is improved, but manufacturing energy consumption increases significantly

Engineering Contradiction:
Improveethanol concentrationVSAvoidmanufacturing energy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The invention maintains continuous useful action by recycling the aqueous ethanol solution back to the reservoir tank, ensuring that ethanol is continuously available for both direct injection and reforming processes. This continuous circulation eliminates the need for periodic dehydration processes, maintaining fuel quality while avoiding the high energy consumption associated with dehydration.

Inventive Principle:
Principle #20Continuity of useful 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 configuration stabilizes the reformed gas components, enhances hydrogen concentration, reduces cooling losses, and increases thermal efficiency by maintaining consistent ethanol concentration and hydrogen-rich gas supply, allowing for high-efficiency engine operation.

Implementation Method 1

the reformed gas including hydrogen can be generated from the aqueous ethanol solution by an endothermic reaction by utilizing its exhaust heat

Methodology Applied
Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 2

as hydrous ethanol has a great latent heat of evaporation to its calorific value, the inside of the combustion chamber can be cooled by directly supplying the hydrous ethanol to the engine

Methodology Applied
Scientific EffectLatent heat of evaporation: Latent Heat

Implementation Method 3

a configuration that a reformed gas fed from the reformer and an unreformed aqueous ethanol solution are separated in a separator

Methodology Applied
Scientific EffectPhase separation: Phase Change

Data Source

PatentEP3147492B1Ethanol engine system
Publication Date: 2020.02.19 HITACHI LTD
  • EP3147492B1 patent drawingFigure 1
  • EP3147492B1 patent drawingFigure 2
  • EP3147492B1 patent drawingFigure 3(a)~3(c)

AI summary

An ethanol engine system is provided that stabilizes components of a reformed gas generated by a reformer and a calorific value of fuel supplied to an engine and has a high thermal efficiency. The ethanol engine system has a characteristic that the system is provided with a reservoir tank 4 for an aqueous ethanol solution, a first supply device 103 that supplies the aqueous ethanol solution in the reservoir tank to the reformer 2, a separator 3 that cools a mixed gas fed from the reformer and including the reformed gas, condenses water vapor included in the mixed gas and separates into gas and liquid, a reformed gas supply device 101 that supplies the reformed gas separated by the separator to the engine 1, a recovery tank 5 that collects a recovery solution separated by the separator, and a first recovery solution supply device 102 that supplies the recovery solution in the recovery tank to the reformer or a second recovery solution supply device 104 that supplies the recovery solution in the recovery tank to a combustion chamber of the engine.