Internal Combustion Engine Injector Start-Up Purging

Solution Overview

Problem

Internal combustion engines face mechanical damage due to increased energy input from an undesirably high mass fraction of liquid fuel in the combustion chamber, often resulting from leakage or operational impairments of the injector, particularly during start-up after a standstill.

Innovation Solution

The method involves actuating the injector during start-up to expel accumulated liquid fuel into the combustion chamber without complete combustion, ensuring it is not burned, thereby reducing inadmissible combustion end pressures and minimizing component damage. This is achieved by controlling the injector to avoid complete combustion in the initial operational cycles, typically during valve overlap phases or after the expansion stroke, and adjusting the actuation time based on predicted fuel quantities to prevent excessive mechanical load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the injector is actuated in regular operational cycles during start-up, then complete combustion of fuel occurs providing necessary energy, but accumulated liquid fuel in the combustion chamber causes excessively high combustion end pressures leading to mechanical damage

Engineering Contradiction:

Improveenergy input from fuel combustionVSAvoidmechanical damage from high combustion pressures

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The injector is actuated in advance during start-up operational cycles to expel accumulated liquid fuel from the injector into the combustion chamber. By performing this preliminary expulsion action before regular combustion begins, the system prevents the harmful effect of high combustion pressures while maintaining the ability to perform complete combustion when needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The injector actuation during start-up is designed to be excessive in terms of fuel expulsion, intentionally introducing more liquid fuel than would normally be required. This excessive action ensures complete purging of accumulated fuel, and the resulting unburnt fuel is safely expelled from the combustion chamber during the exhaust stroke, preventing damage while ensuring thorough cleaning of the injector.

Inventive Principle:

Principle #16Partial or excessive action

2Object-affected harmful factors

If the injector is not actuated during start-up, then mechanical damage from high combustion pressures is avoided, but the injector remains contaminated with accumulated liquid fuel affecting subsequent combustion

Engineering Contradiction:

Improvemechanical damage from high combustion pressuresVSAvoidcombustion performance after standstill

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The injector is actuated in advance during start-up operational cycles to expel accumulated liquid fuel from the injector into the combustion chamber. By performing this preliminary expulsion action before regular combustion begins, the system prevents the harmful effect of high combustion pressures while maintaining the ability to perform complete combustion when needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The accumulated liquid fuel in the injector, which would normally cause harmful high combustion pressures, is converted into a useful purging mechanism. By intentionally expelling this accumulated fuel during start-up, the system cleans the injector of contaminants and ensures reliable subsequent combustion performance.

Inventive Principle:

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

3Use of energy by moving object

If complete combustion is allowed in the combustion chamber during start-up, then energy is efficiently produced, but the accumulated liquid fuel causes inadmissibly high combustion end pressures

Engineering Contradiction:

Improveenergy efficiency from fuel combustionVSAvoidcombustion end pressure

Core Design Contradiction:

Use of energy by moving objectVSStress or pressure

Solution Approach 1:

The injector is actuated in advance during start-up operational cycles to expel accumulated liquid fuel from the injector into the combustion chamber. By performing this preliminary expulsion action before regular combustion begins, the system prevents the harmful effect of high combustion pressures while maintaining the ability to perform complete combustion when needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses periodic operational cycles during start-up where the injector is actuated to expel accumulated fuel. This periodic action alternates between purging the combustion chamber and allowing controlled combustion, ensuring that complete combustion only occurs when safe pressure conditions are maintained.

Inventive Principle:

Principle #19Periodic 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 effectively purges the injector, eliminating undesired liquid fuel leakage and preventing component damage by avoiding high combustion pressures during start-up, ensuring a safe and regular combustion process.

Implementation Method 1

an injector assigned to the combustion chamber, which is configured to introduce a first gaseous fuel into the combustion chamber

Methodology Applied

Scientific EffectFuel injection: Injector

Implementation Method 2

avoiding complete combustion of the fuel introduced into the combustion chamber via the injector

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS12168961B2Method for operating an internal combustion engine, and internal combustion engine

Publication Date: 2024.12.17 WOODWARD LORANGE GMBH

AI summary

The invention relates to a method for operating an internal combustion engine (1), which comprises at least one combustion chamber (3) and an injector (5) which is assigned to the combustion chamber (3) and intended for introducing a first gaseous fuel into the combustion chamber (3), wherein a second liquid fuel is used for operation of the injector (5), wherein in a start-up operation of the internal combustion engine (1) the injector (5) is actuated in at least one operational cycle, avoiding complete combustion of the fuel introduced into the combustion chamber (3) via the injector (5).