Multi-Injector Engine Purging to Reduce Fouling

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Engines face issues with injector fouling and thermal degradation due to prolonged periods between injection events, leading to reduced performance and potential failure, especially when direct injectors are not continuously used, causing soot buildup and increased temperatures.

Innovation Solution

A method is implemented where a purging substance is periodically injected through a second injector during idle periods to reduce fouling and thermal degradation, and the amount of fuel injected via the first injector is adjusted based on the purging substance to maintain the desired air/fuel ratio and torque output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the injector is not continuously injecting fuel, then fuel consumption is reduced and engine efficiency is improved, but injector fouling and thermal degradation occur

Engineering Contradiction:

Improveengine efficiencyVSAvoidinjector performance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies periodic action by implementing intermittent purging of the injector with a purging substance during idle periods between fuel injection events. This periodic purging action prevents fouling and thermal degradation without requiring continuous injection, thus maintaining injector reliability while allowing for reduced fuel consumption and improved engine efficiency during normal operation.

Inventive Principle:

Principle #19Periodic action

2Reliability

If purging substance is injected to reduce fouling, then injector performance is maintained, but air/fuel ratio and torque production vary

Engineering Contradiction:

Improveinjector performanceVSAvoidair/fuel ratio

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies feedback control by using sensors to monitor exhaust gas composition and injector temperature, then adjusting the purging substance injection accordingly. The control system modifies the purging substance injection amount based on real-time feedback from sensors, ensuring that the air/fuel ratio and torque production remain stable while still preventing injector fouling and thermal degradation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting the amount of purging substance injected based on operating conditions such as idle period duration, injector temperature, and exhaust gas composition. The control system varies the purging substance injection parameters (amount, timing, frequency) to maintain optimal air/fuel ratio and torque while preventing fouling.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If injector temperature increases during idle periods, then fuel delivery is reduced, but thermal degradation and fouling increase

Engineering Contradiction:

Improvefuel deliveryVSAvoidthermal degradation

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a purging substance as an intermediary medium that flows through the injector during idle periods to cool the injector components and prevent thermal degradation. This purging substance acts as a thermal intermediary, absorbing heat and preventing direct thermal exposure of the injector to high temperatures, thus protecting the injector while allowing reduced fuel delivery during idle conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively reduces injector fouling and thermal degradation, ensuring consistent engine performance by periodically purging the injectors and adjusting fuel delivery to maintain optimal air/fuel ratios and torque production.

Implementation Method 1

the injection of a substance can cool the injector and/or stagnation of the substance downstream of the injector may remove less heat from injector

Methodology Applied

Scientific EffectThermal cooling: Cooling

Implementation Method 2

a direct injector may become fouled where soot or other products of combustion form on or around the injector nozzle

Methodology Applied

Scientific EffectPhysical cleaning:

Data Source

PatentUS7681554B2Approach for reducing injector fouling and thermal degradation for a multi-injector engine system

Publication Date: 2010.03.23 FORD GLOBAL TECH LLC

AI summary

As one embodiment, a method of operating an engine of a vehicle is provided wherein the engine has a variable engine output. The method comprises during a first engine output, delivering a first fuel to at least a cylinder of the engine via a first injector and directly injecting a second fuel directly into said cylinder via a second injector; and during a second engine output lower than said first engine output, delivering said first fuel to said at least a cylinder of the engine via said first injector and directly injecting at least a purging substance via said second injector based on an idle period since a previous injection by said second injector.