Cylinder Reactivation Control to Minimize NOx and PM Spikes
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Solution Overview
Problem
Cylinder deactivation in internal combustion engines leads to unwanted exhaust gas emissions, such as NOx and PM spikes, due to undesired ratios of cylinder contents during reactivation, which can result in non-compliance with emissions regulations.
Innovation Solution
A system and method utilizing an electric motive device to supplement power during cylinder deactivation and reactivation, where a controller monitors and adjusts the cylinder contents by cycling the cylinders until they reach a desired composition, delaying reactivation until the contents meet predefined thresholds, and using the electric motive device to provide supplemental power until the cylinders are ready for combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If cylinder deactivation mode is used to conserve fuel, then fuel efficiency is improved, but emissions of NOx and PM increase due to undesired cylinder contents ratios during reactivation
Solution Approach 1:
The system performs preliminary cycling of deactivated cylinders before reactivation to prepare optimal cylinder contents. The controller cycles the deactivated cylinders a predetermined number of times to achieve desired air-to-fuel ratio and EGR levels, preventing emissions spikes during subsequent reactivation while maintaining fuel efficiency benefits.
Solution Approach 2:
The system dynamically adjusts cylinder deactivation/reactivation timing and cycling parameters based on real-time operating conditions. The controller monitors power requests and dynamically determines when to reactivate cylinders and how many cycles to perform, optimizing both fuel efficiency and emissions control under varying load conditions.
2Power
If cylinders are reactived immediately when power request exceeds current power output, then power delivery is improved, but emissions spikes occur due to undesired cylinder contents
Solution Approach 1:
Instead of immediate reactivation, the system performs preliminary cycling of the deactivated cylinders to prepare optimal contents. This preliminary action ensures that when cylinders are reactivated for power delivery, the cylinder contents are at desired ratios, preventing emissions spikes while maintaining power delivery capability.
Solution Approach 2:
The system skips immediate reactivation and instead rushes through a predetermined number of cycling cycles to quickly prepare optimal cylinder contents. This allows the system to transition from deactivation to safe reactivation faster, minimizing the delay while ensuring emissions compliance.
3Object-generated harmful factors
If a predetermined number of cycles are performed before reactivation, then emissions are minimized, but response time to power request is delayed
Solution Approach 1:
The system performs a predetermined number of cycles (partial action) rather than waiting for complete equilibrium, which is sufficient to achieve desired emissions control. This partial action approach minimizes the time delay while still achieving the necessary emissions reduction, balancing environmental compliance with responsive power delivery.
Data Source
AI summary
Systems and methods for mitigating exhaust gas emissions via cylinder deactivation are provided. A system includes a controller coupled to an internal combustion engine and an electric motive device. The controller includes a processor and a memory. The memory stores instruction that, when executed by the processor, cause the controller to: receive a power request less than a current power output from the internal combustion engine; command the electric motive device to provide a supplemental power output based on the received power request; command the internal combustion engine to operate in a cylinder deactivation mode whereby at least one cylinder of a plurality of cylinders of the internal combustion engine is deactivated; responsive to determining that a power output of the internal combustion engine is substantially equivalent to the power request after commanding the internal combustion engine to operate in the cylinder deactivation mode, deactivate the electric motive device.