Engine Control Device Premix Time Adjustment
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Solution Overview
Problem
During transitional engine operations, the premix time for fuel and air can become shorter, leading to increased soot production and deteriorated exhaust emissions due to insufficient oxygen, and the existing dual injection strategies for premix charged compressive ignition can exacerbate these issues by reducing the second stage premix time.
Innovation Solution
A control device for an internal combustion engine that calculates and adjusts the second premix time for the second main fuel injection to ensure it meets a predetermined threshold, reducing the fuel injection amount if the premix time is insufficient, and performs an after fuel injection to maintain adequate premix time, thereby preventing soot formation and deteriorated exhaust emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If dual stage injection is performed for premix charged compressive ignition, then combustion noise is reduced, but premix time becomes shorter leading to increased soot production
Solution Approach 1:
The patent dynamically adjusts the injection timing and duration parameters based on engine operating conditions (load, speed, temperature). By changing these parameters, the system ensures adequate premix time even during dual stage injection, preventing soot formation while maintaining the combustion noise reduction benefits
Solution Approach 2:
The injection system transitions from fixed timing to dynamic timing adjustment. The control device modifies injection timing and duration in real-time based on sensor feedback regarding engine load, speed, and thermal state, allowing the premix time to be maintained across varying operating conditions
2Power
If fuel injection amount is increased for higher power output, then engine power increases, but premix time decreases leading to worse exhaust emissions
Solution Approach 1:
The fuel injection is divided into multiple stages (first stage for premix, second stage for power). This segmentation allows the total fuel amount to be increased for power while the first stage maintains adequate premix time for clean combustion, separating the power generation function from the premixing function
Solution Approach 2:
The dual stage injection creates periodic fuel delivery cycles with distinct premixing and power generation phases. The timing and duration of each phase are controlled to ensure proper premixing occurs during the first stage while the second stage delivers additional fuel for power output
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 maintains the premix time, preventing soot production and ensuring better exhaust emissions by adjusting fuel injection amounts and timings to secure sufficient premix time, even during transitional engine operations.
Implementation Method 1
cause premix charged compressive ignition of fuel by successively performing at least a first main fuel injection and a second main fuel injection so as to cause heat to be generated in the combustion chamber two times in stages
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A control device (200) for an internal combustion engine (100) provided with a combustion control part successively performing at least first main fuel injection and second main fuel injection and making the fuel burn by premix charged compressive ignition so as to cause generation of heat two times in stages inside the combustion chamber (11) and cause the pressure waveform showing the change along with time of a rate of cylinder pressure rise to become a two-peak shape. The combustion control part calculates a second premix time of fuel injected by the second main fuel injection with air, reduces the injection amount of the second main fuel injection so that the second premix time becomes a first threshold value or more and performs after fuel injection after the second main fuel injection when the second premix time is less than the first threshold value, and injects the amount of fuel reduced from the injection amount of the second main fuel injection by the after fuel injection.