Engine Control Device Combustion Stability Lean EGR
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Solution Overview
Problem
Existing engine control systems fail to maintain combustion stability during changes in engine temperature, particularly in lean combustion and EGR combustion, leading to decreased efficiency and increased exhaust emissions.
Innovation Solution
An engine control device that adjusts fuel injection ratios during the compression stroke based on engine temperature, increasing the fuel injection amount during the compression stroke to maintain a high combustion speed and stability, while maintaining a total fuel injection amount set by the operating state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If lean combustion or EGR combustion is performed to achieve high efficiency and exhaust gas purification, then fuel economy and emission performance are improved, but combustion stability deteriorates under certain operating conditions
Solution Approach 1:
The patent dynamically adjusts the fuel injection timing and amount based on real-time detection of air-fuel mixture temperature. The control device switches between different injection strategies (intake stroke injection, compression stroke injection, or both) depending on whether the air temperature is higher or lower than the fuel injection temperature, thereby maintaining combustion stability across varying operating conditions while preserving lean combustion benefits
Solution Approach 2:
The patent changes the injection timing parameter (from fixed to variable) based on temperature conditions. When air temperature is high, injection occurs primarily during intake stroke; when air temperature is low, injection is shifted to compression stroke. This parameter adaptation resolves the contradiction by optimizing combustion stability without sacrificing the fuel economy advantages of lean combustion
2Speed
If the jetting division ratio increases fuel injection during intake stroke when air temperature is high, then fuel atomization improves and wall attachment is reduced, but combustion speed decreases when engine temperature drops
Solution Approach 1:
The patent changes the injection timing parameter based on temperature detection. When air temperature exceeds fuel injection temperature, the system increases intake stroke injection to improve atomization. When engine temperature drops, the system shifts injection to compression stroke to maintain combustion speed. This dynamic parameter adjustment resolves the contradiction between atomization quality and combustion stability
Solution Approach 2:
The control device dynamically switches injection strategies based on real-time temperature comparison. The jetting division ratio is not fixed but adapts to thermal conditions, allowing the system to optimize both atomization and combustion speed under different operating scenarios
3Speed
If the jetting division ratio increases fuel injection during compression stroke when air temperature is low, then combustion speed is maintained, but fuel may attach to cylinder walls without vaporizing
Solution Approach 1:
The patent adjusts the injection timing parameter based on temperature conditions. When air temperature is low, the system increases compression stroke injection to maintain combustion speed, but carefully controls the total injection amount and timing to prevent excessive wall attachment. This parameter optimization resolves the contradiction between maintaining combustion speed and minimizing harmful wall attachment
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 suppresses the deterioration of combustion stability and maximizes efficiency and reduces exhaust emissions by ensuring a high combustion speed of the air-fuel mixture, even as engine temperature decreases.
Implementation Method 1
the fuel tends to be atomized by contact with high temperature air, and in such a situation, the amount of fuel attached to a wall surface of the cylinder decreases and the attached fuel also easily evaporates
Data Source
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AI summary
Provided is an engine control device capable of suppressing deterioration of combustion stability due to a change in engine temperature in an engine which performs lean combustion or EGR combustion. When lean combustion in which an air-fuel mixture leaner than a stoichiometric air-fuel ratio is burned or exhaust gas recirculation combustion in which a diluted air-fuel mixture is burned by re-suctioning exhaust gas discharged from the combustion chamber 17 into the combustion chamber 17 is performed, a ratio of a fuel injection amount during a compression stroke to a total fuel injection amount during one combustion cycle is increased as a temperature of an engine 100 decreases.