Dual-Injector Methanol Injection Control for Cold-Start Atomization

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Solution Overview

Problem

Methanol engines suffer from poor low-temperature starting performance due to the high energy required for vaporization and poor atomization of methanol fuel, which is exacerbated by the use of large-flow fuel injectors.

Innovation Solution

A methanol injection system with dual fuel injectors, one in the cylinder and one in the intake pipeline, controlled by a control apparatus to adjust injection strategies based on engine power requirements, optimizing injection ratios and pressures to improve atomization and reduce wall wetting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If large flow methanol fuel injector is used to increase injection rate, then injection volume is improved, but methanol vaporization energy increases and atomization deteriorates

Engineering Contradiction:
Improveinjection rateVSAvoidvaporization energy
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent divides the single large-flow injector into two separate injectors: a first fuel injector for direct cylinder injection and a second fuel injector for intake pipeline injection. This segmentation allows each injector to operate at optimal flow rates, reducing the total vaporization energy required while maintaining adequate injection volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different injection strategies to different locations: direct injection into the cylinder for precise control and atomization, and intake pipeline injection for earlier fuel delivery. This local differentiation optimizes vaporization characteristics at each injection point while maintaining overall injection effectiveness.

Inventive Principle:
Principle #3Local quality

2Loss of time

If large flow methanol fuel injector is used to avoid long injection pulse width, then injection time is reduced, but atomization quality deteriorates

Engineering Contradiction:
Improveinjection pulse widthVSAvoidatomization quality
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

By splitting the injection function between two injectors, the patent can use smaller, more precise injectors that achieve better atomization quality with shorter pulse widths, eliminating the need for a single large-flow injector that compromises atomization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second fuel injector delivers methanol to the intake pipeline before combustion, allowing preliminary mixing and vaporization. This preliminary action reduces the required injection pulse width while improving atomization quality in the combustion chamber.

Inventive Principle:
Principle #10Preliminary action

3Quantity of substance

If methanol injection amount is increased to match air-fuel ratio requirements, then fuel delivery is improved, but wall wetting increases

Engineering Contradiction:
Improveinjection amountVSAvoidwall wetting
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies targeted injection strategies: direct injection into the combustion chamber where fuel is immediately consumed, and controlled intake pipeline injection. This localized approach ensures fuel is delivered precisely where needed, reducing wall wetting while maintaining required injection amounts.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The control apparatus adjusts injection strategies based on engine operating conditions, optimizing the balance between delivery quantity and wall wetting prevention through real-time control of injection timing and distribution.

Inventive Principle:
Principle #23Feedback

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 system enhances cold start performance by reducing vaporization energy and minimizing wall wetting, ensuring efficient methanol injection and improved combustion efficiency across varying loads.

Implementation Method 1

a first fuel injector (11) provided in a cylinder (9) of a methanol engine (9), and a second fuel injector (12) provided in an intake pipeline of a methanol engine (9)

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

methanol fuel needs more energy to vaporize because methanol requires more energy to evaporate per unit mass than gasoline

Methodology Applied
Scientific EffectVaporization: Evaporation

Data Source

PatentEP4579072A1Methanol injection control method, methanol injection system, and vehicle
Publication Date: 2025.07.02 ZHEJIANG GEELY HLDG GRP CO LTD
  • EP4579072A1 patent drawingFigure 1~2
  • EP4579072A1 patent drawingFigure 3~4
  • EP4579072A1 patent drawingFigure 5~7

AI summary

Disclosed are a methanol injection control method, a methanol injection system (100) and a vehicle. The methanol injection control method is applied to the methanol injection system (100). The methanol injection system (100) includes a cylinder communicated with an intake pipeline and an injection structure (1). The injection structure (1) includes a first fuel injector (11) provided in the cylinder and a second fuel injector (12) provided at the intake pipeline. The methanol injection control method includes: (S10), obtaining a required power parameter of the methanol engine; and (S20), determining an injection strategy according to the required power parameter, and controlling an injection of the first fuel injector (11) and/or the second fuel injector (12) according to the injection strategy, so that the injection volume of the first injector (11) and the second injector (12) can be adapted to the load of the methanol engine.