Ammonia Mixed-Combustion Engine Fuel-Ratio Control

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Solution Overview

Problem

Conventional ammonia mixed combustion engines face challenges in maintaining combustion stability and improving exhaust gas properties as the ammonia supply amount increases, leading to higher NH3 and N2O emissions.

Innovation Solution

The ammonia mixed combustion engine adjusts the air excess ratio, liquid fuel injection timing, and injection pressure in response to changes in the ammonia mixed fuel burning ratio to stabilize combustion and enhance exhaust gas properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the ammonia supply amount is increased to increase the mixed fuel burning ratio, then the ammonia mixing ratio is improved, but combustion stability decreases and exhaust gas properties deteriorate

Engineering Contradiction:
Improveammonia mixing ratioVSAvoidcombustion stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent dynamically adjusts the liquid fuel injection timing based on the ammonia mixing ratio. As the ammonia mixing ratio increases, the injection timing is advanced (made earlier) to ensure proper combustion. This dynamic adjustment allows the engine to maintain stable combustion across a wide range of ammonia mixing ratios (0-95%), resolving the contradiction between adaptability and reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the injection timing parameter in response to changes in the ammonia mixing ratio. By advancing the injection timing as the ammonia ratio increases, the combustion process is optimized for each operating condition, maintaining combustion stability while enabling high ammonia mixing ratios.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the ammonia supply amount is increased to increase the mixed fuel burning ratio, then the ammonia mixing ratio is improved, but exhaust gas properties deteriorate and NH3 and N2O emissions increase

Engineering Contradiction:
Improveammonia mixing ratioVSAvoidexhaust gas emissions
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent dynamically adjusts the injection timing to optimize combustion completeness at each ammonia mixing ratio level. By advancing injection timing as ammonia ratio increases, the fuel has more time to mix and burn completely, reducing unburned ammonia and nitrogen oxide emissions while maintaining high ammonia mixing ratios.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent performs preliminary action by advancing the liquid fuel injection timing before the ammonia combustion process begins. This ensures that the liquid fuel is properly atomized and mixed with ammonia and air beforehand, promoting complete combustion and reducing harmful emissions before they can form in the exhaust.

Inventive Principle:
Principle #10Preliminary action

3Object-generated harmful factors

If the timing of liquid fuel supply is controlled to improve exhaust gas properties, then exhaust gas properties are improved, but it becomes difficult to increase the ammonia mixing ratio while also improving combustion stability

Engineering Contradiction:
Improveexhaust gas propertiesVSAvoidammonia mixing ratio
Core Design Contradiction:
Object-generated harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent uses parameter changes (advancing injection timing) to simultaneously achieve multiple goals: improving exhaust gas properties by ensuring complete combustion and enabling higher ammonia mixing ratios. The injection timing parameter is adjusted based on the ammonia mixing ratio to optimize both emission quality and combustion adaptability.

Inventive Principle:
Principle #35Parameter changes

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 engine maintains stable combustion and reduces NH3 and N2O emissions across varying ammonia mixed fuel burning ratios, enhancing operational efficiency and emissions control.

Implementation Method 1

the timing of liquid fuel supply by the supply timing control means is advanced as the ratio of the ammonia supply amount set by the fuel ratio setting means is increased

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

an ammonia mixed combustion engine that operates by burning ammonia and a hydrocarbon liquid fuel

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP4621205A1Ammonia mixed combustion engine
Publication Date: 2025.09.24 YANMAR HLDG CO LTD
  • EP4621205A1 patent drawingFigure 1
  • EP4621205A1 patent drawingFigure 2
  • EP4621205A1 patent drawingFigure 3

AI summary

[Problem] To provide an ammonia mixed combustion engine that enables operation at any ammonia mixed fuel burning ratio and can improve combustion stability and exhaust gas properties. [Solution] An ammonia mixed combustion engine 1 that operates by burning ammonia and a hydrocarbon liquid fuel causes a control unit 2 to implement at least one of decrease or increase in an air excess ratio in fuel, advance or retard in injection timing of the liquid fuel, and decrease or increase in injection pressure of the liquid fuel in accordance with increase or decrease in a mixed fuel burning ratio of ammonia in the fuel.