Multi-Cylinder Engine Fuel Switching for Stable Dual-Fuel Combustion

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Solution Overview

Problem

Existing methods for operating multi-cylinder internal combustion engines with multiple fuels lack reliability and flexibility during fuel transitions, particularly between gaseous and liquid fuels, leading to potential engine disturbances and inefficiencies.

Innovation Solution

A method for operating a multi-cylinder internal combustion engine that involves alternating the introduction of fuels cylinder-by-cylinder, adjusting control parameters to ensure stable transitions by introducing liquid fuel during the work stage and gaseous fuel during the gas exchange stage, with control parameters being used to optimize combustion conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If fuel transition is performed simultaneously in all cylinders, then the switching process is completed quickly, but engine stability deteriorates due to combustion disturbances across multiple cylinders

Engineering Contradiction:
Improvefuel switching timeVSAvoidengine operation stability
Core Design Contradiction:
Loss of timeVSStability of the object's composition

Solution Approach 1:

The fuel transition process is segmented by cylinder, with each cylinder transitioning from gaseous to liquid fuel independently and sequentially. The control system activates liquid fuel injectors cylinder-by-cylinder while deactivating gaseous fuel injectors individually, rather than switching all cylinders simultaneously. This segmentation isolates combustion disturbances to single cylinders during transition, maintaining overall engine stability while completing the fuel switch.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If gaseous fuel injection is stopped before liquid fuel injection starts, then fuel system complexity is reduced, but combustion continuity deteriorates causing engine performance loss

Engineering Contradiction:
Improvefuel injection control complexityVSAvoidengine power output
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The control system performs preliminary action by activating liquid fuel injectors slightly before deactivating gaseous fuel injectors in each cylinder. This overlapping period ensures that liquid fuel is already prepared and positioned in the combustion chamber before gaseous fuel injection completely stops, maintaining continuous combustion and preventing power loss. The preliminary activation of liquid fuel injection bridges the transition gap without requiring complex dual-fuel storage systems.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If control parameters are adjusted for each cylinder individually during fuel transition, then combustion precision is improved, but control system complexity increases

Engineering Contradiction:
Improvecombustion control precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control system applies local quality by adjusting control parameters specifically for cylinders undergoing fuel transition while maintaining standard parameters for cylinders already operating on liquid fuel. Each transitioning cylinder receives customized injection timing and duration adjustments based on its specific transition stage, ensuring optimal combustion precision. The control system manages this complexity through programmed sequences that automatically apply appropriate parameters to each cylinder based on its current operational state.

Inventive Principle:
Principle #3Local quality

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

Ensures stable and efficient operation by minimizing disturbances during fuel transitions, allowing for quick and reliable switching between gaseous and liquid fuels, thereby maintaining engine stability and performance.

Implementation Method 1

liquid fuel is introduced to the engine during work stage and the engine is operated by combusting the liquid fuel in at least two cylinders

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

the introduction of gaseous fuel to the first cylinder is commenced introducing the gaseous fuel to the engine during gas exchange stage

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2893173B1Method of operating a multi-cylinder internal combustion piston engine
Publication Date: 2026.01.28 WARTSILA FINLAND OY
  • EP2893173B1 patent drawingFigure 1

AI summary

A method of operating a multi-cylinder internal combustion piston engine (10) is proposed. The engine comprises a first fuel feed system (20) and a second fuel feed system (30). While the engine is running, the engine is operated by combusting a second fuel in at least two cylinders. The supply of the second fuel to a first one of the at least two cylinders is stopped, and subsequently the supply of a first fuel to the first cylinder is commenced. Control parameters of a combustion process of the first fuel in the first cylinder are controlled and set to reach predetermined conditions of combustion. The first fuel is supplied to and combusted in the second one of the at least two cylinders, using the previously set control parameters.