Direct Injection Engine Split Injection for Homogeneous Mixture
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Solution Overview
Problem
Direct injection type internal combustion engines face issues with non-homogeneous fuel-air mixtures leading to increased THC, CO, and PM emissions, along with decreased engine output and fuel consumption due to local rich mixtures during split fuel injections.
Innovation Solution
A control unit that regulates fuel injection quantities and piston travel proportions to maintain a constant ratio, ensuring balanced fuel-air ratios at each injection, thereby preventing local rich mixtures and improving mixture homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If split fuel injection is performed to reduce emissions, then THC, CO, and PM emissions are reduced, but local rich mixtures are generated in the cylinder due to unbalanced fuel quantity and intake air quantity
Solution Approach 1:
The fuel injection is divided into multiple segments (first injection and second injection) during the intake stroke. The first injection occurs in the first half of the intake stroke and the second injection occurs in the second half, allowing balanced distribution of fuel quantity with intake air quantity throughout the stroke, thereby preventing local rich mixtures while maintaining emission reduction benefits.
2Object-generated harmful factors
If split fuel injection is performed, then emission reduction is achieved, but engine output and fuel consumption decrease due to impaired mixture homogeneity
Solution Approach 1:
The fuel injection is divided into multiple segments (first injection and second injection) during the intake stroke. The first injection occurs in the first half of the intake stroke and the second injection occurs in the second half, allowing balanced distribution of fuel quantity with intake air quantity throughout the stroke, thereby preventing local rich mixtures while maintaining emission reduction benefits.
Data Source
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AI summary
When a direct injection type internal combustion engine is in an operating state, a fuel is split and jetted into a cylinder of the internal combustion engine and split injections are performed in a manner to make a ratio of a piston travel and an injection pulse width of split injection constant in a cycle whereby a rich mixture is not locally generated and a mixture in a cylinder of the internal combustion engine is put in a condition near stoichiometry. Also, when the internal combustion engine is in cold condition, a fuel is split and jetted and split injections are performed so that the ratio of the piston travel and the injection pulse width of split injections monotonously increases in a cycle.