Dual Injector Two-Stroke Engine Fuel Atomization Control
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Solution Overview
Problem
Two-stroke internal combustion engines face challenges with direct fuel injection at high engine speeds, where fuel may not have time to properly atomize, leading to larger droplets and increased soot emissions, while switching to four-stroke engines would result in losing the advantages of two-stroke engines such as simplified construction and more power.
Innovation Solution
A method for controlling a two-stroke engine using an electronic control unit (ECU) to manage fuel injection by the port fuel injector and direct fuel injector, adjusting the fuel ratios and injection timing to compensate for fuel sticking to engine surfaces and ensure adequate fuel supply to the combustion chamber, particularly during phase-in and phase-out operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct fuel injection is used in two-stroke engines, then fuel quantity control precision and emission reduction are improved, but at very high engine speeds fuel atomization is insufficient leading to increased soot emissions
Solution Approach 1:
The fuel injection system is segmented into two separate injectors: a port fuel injector that delivers fuel upstream of the combustion chamber allowing time for atomization, and a direct fuel injector that provides precise fuel quantity control directly into the combustion chamber. This segmentation allows each injector to specialize in one function, resolving the contradiction between precise control and proper atomization.
Solution Approach 2:
The port fuel injector performs preliminary fuel delivery upstream of the combustion chamber before the combustion event, allowing the fuel to atomize and mix with air in advance. This preliminary action ensures proper fuel atomization at high engine speeds, preventing soot formation while the direct injector handles precise quantity control.
2Object-generated harmful factors
If port fuel injection is used, then fuel atomization is improved, but fuel quantity control precision is reduced compared to direct injection
Solution Approach 1:
The system segments the fuel injection function between two injectors: the port fuel injector handles fuel delivery and atomization upstream, while the direct fuel injector handles precise quantity control into the combustion chamber. This division allows each component to optimize for its specific function.
Solution Approach 2:
The system merges the advantages of both port fuel injection and direct fuel injection into a hybrid system. The port injector provides the atomization benefits of port injection, while the direct injector provides the precision control of direct injection, combining both benefits in a single system.
3Power
If two-stroke engine configuration is maintained, then construction simplicity and power output are preserved, but direct fuel injection at high speeds causes insufficient fuel atomization
Solution Approach 1:
The dual injector system segments fuel delivery functions to resolve the atomization problem at high speeds while maintaining the two-stroke power advantage. The port injector ensures proper atomization timing, allowing the two-stroke engine to maintain high power output without excessive soot emissions.
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 allows for improved fuel atomization and reduced soot emissions by optimizing fuel injection strategies, maintaining the advantages of two-stroke engines while addressing the limitations of direct fuel injection at high speeds.
Implementation Method 1
the fuel may not have the time to properly atomized, resulting in larger droplets of fuel being combusted
Implementation Method 2
direct fuel injectors such as the E-TECTM fuel injector from BRPTM. The direct fuel injectors inject fuel directly into the combustion chambers of the engine
Implementation Method 3
Two-stroke internal combustion engine burn a mixture of fuel and oil
Data Source
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AI summary
A two-stroke internal combustion engine has a crankcase, a cylinder block defining at least one cylinder, a cylinder, a crankshaft, at least one piston, at least one scavenge port, at least one throttle body for supplying air to an interior of the crankcase, at least one direct fuel injector fluidly communicating with at least one combustion chamber for injecting fuel directly in the at least one combustion chamber; and at least one port fuel injector fluidly communicating with the interior of the crankcase for injecting fuel upstream of the at least one combustion chamber. Methods for controlling an engine having at least one direct fuel injector and at least one port fuel injector are also described.