Spark Ignition Engine Load Threshold Adjustment for Soot Control
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Solution Overview
Problem
Existing engine particulate filters are less efficient in trapping soot, leading to emissions, especially at cold temperatures and higher engine loads, with small amounts of soot potentially passing through due to inefficiencies.
Innovation Solution
Adjusting the maximum engine load threshold based on the amount of soot stored in the particulate filter, lowering it when soot is low to reduce soot generation and increasing it when soot is high to optimize trapping efficiency and meet power demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the engine operates at higher loads to meet power demand, then power output increases, but soot generation increases and trapping efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the engine load threshold adjustable rather than fixed. The controller dynamically modifies the maximum engine load threshold based on real-time monitoring of soot stored in the particulate filter. When soot accumulation is low, the threshold allows higher engine loads for maximum power output. When soot accumulation increases, the threshold is reduced to limit further soot generation, thus dynamically balancing power delivery with emissions control
Solution Approach 2:
The patent implements feedback control by continuously monitoring the amount of soot stored in the particulate filter and using this information to adjust the engine load threshold. The controller receives feedback about filter soot levels and automatically modifies the maximum allowable engine load accordingly, creating a closed-loop control system that adapts to changing soot accumulation conditions
2Object-generated harmful factors
If the maximum engine load is limited to reduce soot generation, then soot emissions decrease, but power output is reduced
Solution Approach 1:
The engine load threshold is made dynamic and adaptive rather than statically limited. The controller adjusts the maximum engine load threshold in real-time based on soot accumulation in the particulate filter. This allows the system to permit high power output when conditions are favorable (low soot levels) while automatically restricting power when needed (high soot levels), optimizing both power delivery and emissions control throughout operation
Solution Approach 2:
The patent changes the parameter of maximum engine load threshold from a fixed value to a variable that changes based on soot accumulation conditions. The controller modifies this parameter dynamically, increasing it when soot levels are low to allow maximum power output, and decreasing it when soot levels are high to reduce further soot generation, thus using parameter changes to balance conflicting requirements
3Object-generated harmful factors
If the particulate filter traps more soot to reduce emissions, then soot trapping efficiency increases, but pressure drop increases reducing engine performance
Solution Approach 1:
The patent applies preliminary action by proactively limiting engine load before the particulate filter becomes overly saturated. By monitoring soot accumulation and reducing the maximum engine load threshold in advance, the system prevents excessive pressure drop from developing. This anticipatory approach maintains engine performance by avoiding the point where filter clogging would significantly restrict exhaust flow and power output
Solution Approach 2:
The system provides beforehand cushioning by creating a buffer through dynamic load management. Before the particulate filter reaches a state where pressure drop would severely impact engine performance, the controller reduces the maximum engine load threshold, effectively cushioning against the negative effects of filter saturation. This protective measure maintains engine performance by preventing operation conditions that would cause excessive backpressure
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 reduces engine soot emissions without noticeable power loss, increasing opportunities for less soot generation while providing maximum power when needed, and improves soot trapping efficiency as soot accumulates.
Implementation Method 1
The particulate filter may trap carbonaceous soot during times when the engine may generate some soot
Implementation Method 2
the particulate filter may be regenerated via oxidizing soot within the particulate filter
Data Source
AI summary
Systems and methods for operating a spark ignition engine that includes a particulate filter in the engine's exhaust system are described. In one example, the spark ignition engine is prevented from exceeding a threshold engine load when the engine is supplying power to an electric machine so that engine emissions may be reduced.