Spray-Guided Spark-Ignition Direct Injection Engine Combustion Control
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Solution Overview
Problem
Current spark-ignition, direct-injection gasoline engines face challenges in controlling combustion variability, fuel efficiency, and reducing engine-out emissions due to the long interval between fuel injection pulses, which limits interaction with the spark plug and results in misfires and incomplete combustion.
Innovation Solution
A method and system for a spray-guided, spark-ignition, direct fuel injection engine that involves injecting multiple fuel pulses, with a first pulse during the combustion cycle and a second pulse timed to form an ignitable fuel-air mixture near the spark plug during spark ignition, optimizing the elapsed time between pulses based on engine load to ensure consistent combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple fuel injection pulses are used in spark-ignition direct injection engines, then combustion control and fuel efficiency are improved, but the time interval between injection pulses becomes too large to allow interaction with spark arc
Solution Approach 1:
The fuel injection process is segmented into multiple pulses within a single combustion cycle. The first pulse injects fuel early in the compression stroke to form a stratified charge, while the second pulse injects fuel later to ensure adequate mixture near the spark plug. This segmentation allows each pulse to serve a specific function in the combustion process, improving reliability while managing the time interval constraint.
Solution Approach 2:
The first fuel injection pulse is performed in advance during the compression stroke to prepare a stratified charge distribution. This preliminary action creates favorable conditions for subsequent spark ignition and the second injection pulse, ensuring that fuel is already positioned optimally in the combustion chamber before the spark event occurs.
2Productivity
If multiple fuel injection pulses are used, then fuel efficiency and emission reduction are improved, but combustion variability increases due to timing constraints
Solution Approach 1:
The injection timing, duration, and quantity parameters are dynamically adjusted based on engine operating conditions. The control system modifies these parameters to optimize the balance between achieving good fuel efficiency through multiple pulses and maintaining combustion stability by ensuring appropriate mixture formation near the spark plug across different operating regimes.
Solution Approach 2:
The control system uses feedback from various sensors to monitor combustion quality and adjust injection parameters in real-time. This feedback mechanism allows the system to compensate for variations in combustion behavior, reducing combustion variability while maintaining the fuel efficiency benefits of multiple injection pulses.
3Object-generated harmful factors
If multiple fuel injection pulses are used, then engine-out emissions are reduced, but misfires and incomplete combustion occur due to insufficient mixture formation near spark plug
Solution Approach 1:
The injection strategy creates different fuel distribution patterns in different regions of the combustion chamber. The first pulse creates a stratified charge with higher fuel concentration in certain areas, while the second pulse ensures adequate fuel mixture specifically near the spark plug region. This local quality differentiation ensures both emission reduction through stratification and reliable ignition through proper mixture near the spark source.
Data Source
AI summary
A method and article of manufacture are provided to operate a spray-guided, spark-ignition, direct fuel injection engine, including injecting a first fuel pulse during a combustion cycle, and initiating spark ignition by energizing a spark igniter. A second fuel pulse is injected during the combustion cycle effective to form an ignitable fuel-air mixture proximal to the spark igniter during a period in time whereat the spark igniter is energized. A preferred elapsed time between an end of the first fuel pulse and start of the spark ignition is determined based upon engine load.