Fuel Injector Nozzle Passivation for Deposit Reduction

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Solution Overview

Problem

Existing methods for controlling deposit formation on fuel injectors in internal combustion engines are inefficient and costly, as they often require extensive procedures and equipment, and fail to effectively address the issue of coking or deposit growth on the outside of injector nozzles, which can lead to fuel flow restrictions and engine performance issues.

Innovation Solution

The application of surface passivation techniques, such as chemical coatings and mechanical texturing, specifically on the outside of fuel injector nozzles, combined with fuel compositions containing additives like detergents and manganese tricarbonyl compounds, to prevent deposit formation by promoting carbon oxidation at lower temperatures and reducing soot loading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If surface passivation techniques are applied to the outside of fuel injector nozzles, then deposit formation is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvedeposit formation controlVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies passivation treatment selectively only to the outer surface of the injector nozzle, not the entire injector component. This localized approach reduces deposit formation at the critical interface where deposits initiate, while minimizing the scope of complex manufacturing procedures required

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The passivation treatment is applied during the manufacturing process before the injector is installed in the engine. This preliminary action prevents deposit formation from occurring in the first place, eliminating the need for complex maintenance and cleaning procedures later

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If passivation is applied only to the outside of the injector nozzle, then manufacturing cost is reduced, but deposit control effectiveness may be compromised

Engineering Contradiction:
Improvemanufacturing costVSAvoiddeposit control effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention identifies that deposit formation initiates specifically at the outer surface of the nozzle where it contacts hot gases and fuel vapor. By applying passivation only to this critical external surface, the patent achieves effective deposit control while avoiding the cost of treating the entire injector assembly

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent extracts and addresses only the specific portion of the injector (the outer nozzle surface) where deposit initiation occurs, rather than treating the entire injector. This focused approach reduces manufacturing costs while maintaining effectiveness

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If fuel compositions contain detergent additives, then deposit formation is reduced, but fuel cost increases

Engineering Contradiction:
Improveinjector performanceVSAvoidfuel cost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The passivated surface creates a preliminary protective barrier that prevents deposits from adhering to the injector nozzle. This preliminary protection reduces the amount of detergent additive needed in the fuel to maintain clean injectors, thereby reducing fuel costs while preserving injector performance

Inventive Principle:
Principle #9Preliminary anti-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 reduces deposit formation on fuel injectors by targeting the initial growth of deposits on the outside of the nozzle, thereby improving engine efficiency, reducing maintenance costs, and enhancing fuel spray consistency and emission control.

Implementation Method 1

promoting carbon oxidation at lower temperatures

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

Surface passivation and the methods for the reduction of fuel thermal degradation deposits

Methodology Applied
Scientific EffectPassivation: Coatings

Data Source

PatentUS8069826B2Surface passivation and the methods for the reduction of fuel thermal degradation deposits
Publication Date: 2011.12.06 AFTON CHEMICAL CORPORATION

AI summary

In a specific embodiment of this invention, deposits and soot formation in a direct injection engine are reduced by passivating the injectors to within 0.1 mm of the injector nozzle. The fuel used with the inventive injectors comprises fuel-soluble additives.