Engine Control Apparatus Managing In-Cylinder Density via EGR and Condensed Water
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Solution Overview
Problem
The increase in EGR gas supply in internal combustion engines leads to higher in-cylinder density, impairing fuel spray diffusion and resulting in increased smoke and hydrocarbon (HC) emissions, as well as cooling losses due to fuel adhesion to the cylinder walls.
Innovation Solution
A control apparatus that adjusts the supply rate of EGR gas and a low-density substance, such as condensed water, based on the equivalence ratio to optimize in-cylinder density, promoting fuel spray diffusion and reducing HC emissions by varying the EGR gas and low-density substance supply rates in response to changes in equivalence ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the in-cylinder density is increased by supplying EGR gas, then the diffusion of fuel spray is impaired, but the penetration of fuel spray is reduced which decreases cooling loss and fuel adhesion to cylinder walls
Solution Approach 1:
The invention dynamically adjusts the in-cylinder density parameter by controlling the supply rates of both EGR gas (high density) and condensed water (low density). This enables optimization of both fuel spray penetration (for reduced cooling loss) and fuel spray diffusion (for reduced smoke and HC) by finding the appropriate density level for each operating condition
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 control apparatus effectively reduces in-cylinder density at high equivalence ratios, enhancing fuel spray diffusion and minimizing smoke and HC emissions, while maintaining NOX generation suppression and reducing cooling losses by appropriate penetration control.
Implementation Method 1
The condensed water supplied to the intake passage is led into a cylinder together with intake air and vaporized in the cylinder, thereby suppressing a combustion temperature
Implementation Method 2
when the equivalence ratio is high, a supply rate of the low density substance increases and a supply rate of the EGR gas decreases... the in-cylinder density decreases when the equivalence ratio is high
Implementation Method 3
an EGR apparatus that supplies a part of exhaust gas into the cylinder as EGR gas... the amount of generated NOX can be reduced by supplying EGR gas into the cylinder
Data Source
AI summary
A control apparatus for an internal combustion engine according to the invention is applied to an internal combustion engine in which EGR gas and condensed water generated by an EGR cooler are supplied into a cylinder. The control apparatus calculates an equivalence ratio of the internal combustion engine, and controls an EGR valve and a condensed water supply valve such that, when the equivalence ratio is high, a supply rate of the condensed water increases and a supply rate of the EGR gas decreases relative to when the equivalence ratio is low.