Engine Cylinder Group Segmentation for Cold Start HC Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Internal combustion engines face challenges in reducing unburned hydrocarbon (HC) emissions during cold starts, especially when using alcohol-blended fuels, due to the low volatility of alcohol, which can lead to misfires and increased HC discharge, as existing technologies struggle to supply the necessary fuel effectively.
Innovation Solution
A control apparatus and method that initiates combustion in only some cylinders initially and then in the remaining cylinders after startup, using an engine starting portion, intake pipe pressure monitoring, alcohol concentration information, and necessary fuel injection quantity calculation to ensure accurate fuel supply, reducing HC emissions by adjusting fuel injection based on intake pipe pressure and alcohol concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of fuel is supplied to each cylinder at startup to ensure ignitable concentration, then the engine can start reliably, but unburned HC emissions increase significantly
Solution Approach 1:
The patent divides the cylinders into two groups: a first cylinder group that supplies fuel at startup and a second cylinder group that stops fuel supply. This segmentation allows the engine to start with fewer cylinders active, reducing total HC emissions while maintaining reliable starting through concentrated fuel supply to the first group.
Solution Approach 2:
The patent applies different fuel supply strategies to different cylinder groups. The first cylinder group receives fuel supply optimized for reliable combustion, while the second cylinder group receives no fuel supply during startup. This local differentiation reduces overall HC emissions while ensuring engine starting reliability.
2Object-generated harmful factors
If fuel containing alcohol is used to reduce emissions, then environmental performance improves, but the low volatility of alcohol causes misfires and increases HC discharge during cold starts
Solution Approach 1:
By segmenting cylinders into two groups with different fuel supply strategies, the system can use alcohol-blended fuel during normal operation for emission reduction while ensuring reliable combustion during cold starts through concentrated fuel supply to the first cylinder group.
Solution Approach 2:
The patent supplies fuel to only one cylinder group during startup rather than all cylinders, creating a concentrated fuel supply that overcomes the low volatility of alcohol and ensures reliable combustion, while still achieving emission reduction through the partial activation approach.
3Reliability
If fuel is supplied to all cylinders at startup, then each cylinder has sufficient fuel for combustion, but the total amount of unburned HC discharged increases
Solution Approach 1:
The patent segments the cylinder group into a first cylinder group that supplies fuel and a second cylinder group that stops fuel supply. This ensures sufficient fuel for combustion in the first group while eliminating fuel consumption and HC discharge from the second group, reducing total HC emissions.
Solution Approach 2:
The patent extracts the second cylinder group from the fuel supply system during startup, stopping fuel supply to these cylinders. This removes the source of potential unburned HC emissions from these cylinders while maintaining combustion reliability through the first cylinder group.
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 unburned HC emissions by ensuring the right amount of fuel is supplied to the cylinders, preventing both lean and rich misfires, even when using alcohol-blended fuels, thereby improving engine starting efficiency and reducing HC discharge.
Implementation Method 1
monitors a change in an amount of negative pressure generated in an intake pipe with the starting of the internal combustion engine
Implementation Method 2
the rest of the fuel temporarily adheres to the wall surface of the intake port. The fuel that has adhered to the intake port vaporizes from negative pressure inside the intake pipe or the heat from the wall surface of the intake port
Implementation Method 3
The engine starting portion starts the internal combustion engine by initiating combustion in cylinders belonging to a first cylinder group
Data Source
AI summary
A control apparatus for an internal combustion engine starts the internal combustion engine by initiating combustion in cylinders belonging to a first cylinder group, from among a plurality of cylinders that make up the internal combustion engine. The control apparatus monitors a change in an amount of negative pressure generated in an intake pipe when the internal combustion engine is started, and obtains information related to an alcohol concentration of fuel used in the internal combustion engine. The control apparatus also calculates a fuel injection quantity necessary to initiate combustion in cylinders belonging to a second cylinder group, based on the amount of negative pressure generated in the intake pipe and the alcohol concentration of the fuel, and initiates combustion in each cylinder belonging to the second cylinder group when the necessary fuel injection quantity enters a range of quantities that are able to be injected by corresponding injectors.