Diesel Engine Control Combustion Rate Feedback
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Solution Overview
Problem
Existing engine control systems for diesel engines face challenges in accurately controlling pilot injection quantities, leading to excess fuel adhesion to cylinder walls, which increases unburned fuel and deteriorates emissions and fuel efficiency, especially in hostile environments or conditions where desired heat generation is difficult to achieve.
Innovation Solution
An engine control apparatus that determines a combustion rate as the ratio of ideal to actual heat generation, allowing for variable injection quantity and pattern control to maintain desired combustion conditions, using a combustion rate determining means and increasing means to adjust parameters such as ignition assist devices and intake air charging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If pilot injection quantity is increased to meet desired heat generation quantity, then heat generation is improved, but fuel adhesion to cylinder wall increases and emissions deteriorate
Solution Approach 1:
The control apparatus uses feedback from the cylinder pressure sensor to continuously monitor actual heat generation and adjusts pilot injection quantity accordingly. The system compares actual heat generation with target values and modifies injection parameters to maintain optimal combustion while preventing fuel adhesion.
Solution Approach 2:
The system dynamically changes multiple parameters including injection timing, injection pressure, and injection quantity based on combustion conditions. By adjusting these parameters together rather than increasing injection quantity alone, the system achieves target heat generation without excessive fuel adhesion.
2Object-generated harmful factors
If pilot injection quantity is precisely controlled to reduce fuel adhesion, then emissions are improved, but heat generation may be insufficient
Solution Approach 1:
The feedback mechanism ensures that pilot injection quantity is not arbitrarily reduced but adjusted based on actual combustion performance. The cylinder pressure sensor data allows the system to maintain sufficient heat generation while minimizing fuel adhesion through precise, condition-based control.
Solution Approach 2:
The injection control is made dynamic and adaptive rather than static. The system continuously adjusts pilot injection quantity based on real-time combustion conditions, allowing optimal balance between heat generation and fuel adhesion prevention under varying engine operating conditions.
3Reliability
If injection quantity is increased to compensate for aging components, then combustion performance is maintained, but fuel adhesion increases
Solution Approach 1:
The feedback system detects changes in combustion characteristics over time and adjusts injection parameters to compensate for component aging. By continuously monitoring actual heat generation and comparing it with target values, the system maintains optimal combustion performance without excessive fuel adhesion even as components age.
Solution Approach 2:
The system performs preliminary adjustments to injection parameters based on detected combustion characteristics before fuel adhesion problems can occur. By proactively adjusting injection quantity and timing based on real-time feedback, the system prevents fuel adhesion issues rather than reacting to them after they develop.
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 enables precise control of combustion conditions, reducing emissions and maintaining fuel efficiency by ensuring the combustion rate remains within optimal limits, even as engine conditions change over time, such as due to aging components.
Implementation Method 1
a combustion rate determining means for determining a combustion rate corresponding to the ratio of a target heat generation quantity, which is an ideal heat quantity estimated to be generated from a fuel supply quantity, and an actual heat generation quantity, which is a heat quantity actually generated from the fuel supply quantity
Data Source
AI summary
An engine control apparatus comprised of an engine control ECU has a program preloaded therein for determining a combustion rate (actual combustion rate) corresponding to the ratio of an ideal heat generation quantity (target heat generation quantity) estimated to be generated from a fuel supply quantity, and an actual heat generation quantity actually generated by the fuel supply quantity. The engine control apparatus controls pilot injection timing with a controlled variable corresponding to the thus determined combustion rate so as to increase the combustion rate.