Auto-Ignition Control via Multi-Wavelength UV Irradiation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Internal combustion engines face inefficiencies and varying ignition delays due to the inhomogeneity of combustion chemistry, with existing laser-based ignition methods limited in controlling chemical processes and achieving optimal heat release timing.

Innovation Solution

The method involves targeted ultraviolet irradiation of specific wavelengths (200-310 nm) to dissociate intermediate species in the combustion chamber, controlling the pre-ignition phase and promoting efficient combustion by generating reactive radicals, using light sources like LEDs to optimize the chemical path towards ignition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser light is used to produce OH or CH radicals for ignition, then ignition can be achieved under specific conditions, but the method is limited in controlling chemical processes and achieving optimal heat release timing due to inhomogeneity of combustion chemistry

Engineering Contradiction:
Improveignition controlVSAvoidchemical process control
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by using multiple light sources with different wavelengths (200-310 nm and 345-365 nm) targeted at specific locations in the combustion chamber. Different wavelengths target different intermediate species (H2O2, CH2O, OH, CH radicals) at different spatial zones, allowing localized control of combustion chemistry to address inhomogeneity and achieve optimal heat release timing throughout the chamber.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes parameters by utilizing multiple wavelength ranges (200-310 nm for H2O2 and CH2O dissociation, 345-365 nm for OH and CH radical generation) instead of a single wavelength. This multi-parameter approach enables control over different stages of combustion chemistry, allowing adjustment of ignition timing and heat release rate to achieve optimal combustion control under varying engine conditions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a coherent light source (laser with a single wavelength) is used, then a specific radical can be targeted, but only a very limited effect can be achieved

Engineering Contradiction:
Improveradical targeting precisionVSAvoidcombustion control effectiveness
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent segments the combustion control process by dividing it into multiple wavelength-specific stages: 200-310 nm for dissociating H2O2 and CH2O, and 345-365 nm for generating OH and CH radicals. Multiple light sources operate at different wavelengths simultaneously or sequentially, each targeting specific intermediate species, thereby achieving comprehensive control over the combustion chemistry rather than limiting control to a single radical type.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements multi-functionality by using a combination of light sources that perform multiple functions: dissociating H2O2, dissociating CH2O, generating OH radicals, and generating CH radicals. This universal approach allows a single combustion control system to address various stages of combustion chemistry, significantly enhancing overall combustion control effectiveness compared to single-wavelength lasers.

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

3Use of energy by moving object

If OH groups or CH groups are excited, then the respective radicals cannot be generated, but existing methods fail to achieve efficient combustion control

Engineering Contradiction:
Improveenergy conversion efficiencyVSAvoidcombustion efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent applies preliminary action by first dissociating H2O2 and CH2O molecules using 200-310 nm light to create precursor species, then subsequently generating OH and CH radicals using 345-365 nm light. This two-stage preliminary action ensures that the necessary intermediate species are prepared before main combustion, enabling efficient energy conversion and high combustion productivity by controlling the chemical pathways leading up to ignition.

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 approach allows for precise control of combustion timing and location, enhancing efficiency and reducing pollutant emissions by accelerating or decelerating the ignition process, achieving high efficiency and low emission operation even with lean and stratified fuel mixtures.

Implementation Method 1

irradiation at one or more wavelengths greater than 200 nm and less than 310 nm to dissociate intermediate species in the combustion chamber

Methodology Applied
Scientific EffectPhotodissociation: Photodissociation

Implementation Method 2

irradiation at one or more wavelengths greater than 200 nm and less than 310 nm and/or at wavelengths of at least 345 nm and at most 365 nm

Methodology Applied
Scientific EffectPhotodissociation: Photodissociation

Data Source

PatentEP3347580B1Auto-ignition control method of an internal combustion engine
Publication Date: 2019.09.04 TOYOTA JIDOSHA KK
  • EP3347580B1 patent drawingFigure 1
  • EP3347580B1 patent drawingFigure 2
  • EP3347580B1 patent drawingFigure 3a~3b

AI summary

The present invention is directed to a method of enhanced combustion of hydrocarbon fuel by oxygen in an internal combustion engine wherein: - both oxidiser and a hydrocarbon fuel are introduced into the combustion chamber of an internal combustion engine; - optical energy is provided in the combustion chamber to the oxidiser- fuel mixture and/or reaction products of oxidiser/fuel mixing, using irradiation at one or more wavelengths greater than 200 nm and less than 310 nm and/or at wavelengths of at least 345 nm and at most 365 nm. Combustion apparatus that can be used in such a method of enhanced combustion is also described.