Diesel Fuel Injection Timing Compensation for Cetane Variations
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Solution Overview
Problem
Diesel fuel with varying cetane numbers can lead to changes in combustion phase, resulting in increased engine emissions, noise, and fuel consumption, as different refiners process diesel fuel differently and additives may be mixed based on season, affecting engine performance.
Innovation Solution
Adjusting the number and timing of fuel injections in a diesel engine cylinder in response to changes in cetane number, by transferring fuel amounts between injection pulses to maintain optimal combustion phase and reduce emissions and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the start of injection timing is adjusted to compensate for fuels having different cetane numbers, then combustion phase can be maintained, but engine hydrocarbon emissions and particulate matter increase
Solution Approach 1:
The fuel injection is divided into multiple separate pulses instead of a single injection event. By segmenting the total fuel amount into multiple injections (e.g., pilot injection, main injection, post injection), the system can compensate for cetane number variations while controlling emissions. Each pulse serves a specific function in managing combustion phase and reducing harmful emissions.
Solution Approach 2:
The injection strategy dynamically adapts based on detected combustion phase deviations caused by cetane number variations. The control system modifies injection timing, duration, and distribution across multiple pulses in real-time to maintain optimal combustion phase while minimizing hydrocarbon emissions and particulate matter.
2Reliability
If the number of fuel injections is adjusted to compensate for cetane number variations, then combustion phase can be controlled, but system complexity increases
Solution Approach 1:
The existing multi-pulse injection system, originally designed for emissions control and noise reduction, is leveraged to additionally compensate for cetane number variations. The same injection pulses that control combustion noise and particulate matter are also used to adjust combustion phase, eliminating the need for separate compensation mechanisms and reducing overall system complexity.
Solution Approach 2:
The fuel injection system uses its own existing capability of multiple pulses to solve the cetane compensation problem. By redistributing fuel amounts among the already-present injection pulses, the system achieves combustion phase control without adding external complexity, making the solution self-contained within the existing injection architecture.
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 reduces engine emissions and noise by compensating for cetane number variations, improving combustion efficiency and maintaining desired combustion phases, while accounting for fuel injector limitations.
Implementation Method 1
a fuel injector delivering fuel to a cylinder in a plurality of pulses
Implementation Method 2
the first fuel mixture ignited via compression ignition
Implementation Method 3
combusting a first fuel in a cylinder
Data Source
AI summary
Methods and systems for adjusting a plurality of fuel injections supplied to a cylinder during a cycle of the cylinder are described. In one example, fuel amounts are moved between fuel injections in response to combustion phase. Engine feedgas hydrocarbons and/or carbonaceous particulate matter may be reduced when cetane of combusted fuel changes.