Engine Mixing Structure for Soot Reduction

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Solution Overview

Problem

Compression ignition engines face challenges in reducing soot formation due to sub-optimal fuel-and-air mix ratios and high ignition delays, which degrade engine performance and violate emission regulations.

Innovation Solution

A mixing structure is introduced that includes conduit surfaces and air channels to control the fuel-and-air mixture ratio, delaying ignition by cooling the gases through thermal transfer, thereby reducing soot production and improving combustion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If fuel is directly injected into compressed hot gases, then the delay between injection and ignition is reduced, but the fuel-and-air mix ratio becomes sub-optimal and soot is produced

Engineering Contradiction:

Improveignition delayVSAvoidsoot production

Core Design Contradiction:

Loss of timeVSObject-generated harmful factors

Solution Approach 1:

The mixing structure segments the fuel injection process into distinct zones: a central volume for initial fuel injection and mixing, surrounded by annular passages for air introduction. This segmentation allows controlled mixing in stages, ensuring optimal fuel-air ratio before combustion while managing ignition timing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the mixing structure provide different functions: the central volume provides intense mixing for fuel atoms, the annular passages provide controlled air introduction, and the spray plume region provides combustion. This local differentiation enables simultaneous optimization of mix ratio and ignition delay in different zones.

Inventive Principle:

Principle #3Local quality

2Loss of time

If the temperature of entrained gases remains high, then the ignition delay is reduced, but the fuel-and-air mix ratio becomes sub-optimal

Engineering Contradiction:

Improveignition delayVSAvoidfuel-and-air mix ratio

Core Design Contradiction:

Loss of timeVSQuantity of substance

Solution Approach 1:

The mixing structure performs preliminary mixing of fuel and air in the central volume and annular passages before the mixture enters the combustion zone. This preliminary action ensures optimal fuel-air ratio is achieved prior to ignition, allowing controlled combustion even with reduced ignition delay from high temperatures.

Inventive Principle:

Principle #10Preliminary action

3Loss of time

If fuel mixes with high temperature gases, then ignition delay is reduced, but soot build-up degrades engine performance

Engineering Contradiction:

Improveignition delayVSAvoidengine performance

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The mixing structure acts as an intermediary device between fuel injection and combustion chamber. It provides a controlled environment for fuel-air mixing with specific geometric features (central volume, annular passages, spray plume region) that ensure optimal mix ratio and reduce soot formation before gases enter the combustion zone, thereby protecting engine performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Object-generated harmful factors

If a mixing structure with multiple conduits and air channels is introduced, then fuel-and-air mix ratio is optimized and soot is reduced, but device complexity increases

Engineering Contradiction:

Improvesoot formationVSAvoidmixing structure complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The mixing structure merges multiple functions into a single integrated component: fuel injection port, central mixing volume, annular air passages, and spray plume region all combine in one structure. This merging achieves optimal fuel-air mixing and soot reduction while minimizing the number of separate parts that would increase complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The mixing structure serves multiple functions simultaneously: it atomizes fuel, mixes fuel with air, controls ignition timing, and reduces soot formation. This multi-functionality in a single component optimizes engine performance and reduces emissions without requiring multiple separate devices.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 mixing structure effectively delays ignition, reduces soot formation, and enhances combustion efficiency by ensuring a leaner fuel-and-air mix, meeting emission regulations and extending engine maintenance intervals.

Implementation Method 1

delaying ignition by cooling the gases through thermal transfer

Methodology Applied

Scientific EffectThermal transfer: Conduction (thermal)

Data Source

PatentUS11549429B2Engine mixing structures

Publication Date: 2023.01.10 TRANSPORTATION IP HOLDINGS LLC

AI summary

A fuel and gas mixing structure for an engine is provided. This mixing structure includes a body configured to be positioned between a fuel injector and a cylinder of an engine. The body defines an interior volume that is configured to receive gas (e.g., air) from outside the body and to receive one or more streams of fuel from the fuel injector in the interior volume. The body also includes one or more upper channels and one or more lower channels that are configured to provide a substantially similar amount of flow relative to each other to the interior volume The body also defines one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.