DPF Passive Regeneration via Powertrain Torque-Speed Management
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Solution Overview
Problem
Current diesel particulate filter (DPF) regeneration methods, especially in lean burning engine systems, face challenges with excessive fuel use and frequent active regeneration cycles due to soot production transients, making it difficult to manage soot load and optimize passive regeneration.
Innovation Solution
A system and method that utilize a Cycle Efficiency Management (CEM) module to optimize powertrain operations by receiving current and terrain data, determining target operating states, and providing engine speed and transmission gear shift recommendations to reduce engine exhaust particulate matter and transients, thereby enhancing passive regeneration opportunities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active DPF regeneration cycles are used to burn off accumulated PM, then the DPF can be regenerated, but excess fuel is consumed and cost increases
Solution Approach 1:
The system performs preliminary action by detecting soot load accumulation in the DPF and proactively scheduling regeneration cycles before the filter becomes completely blocked. The controller monitors DPF differential pressure to estimate soot load and initiates active regeneration at optimal times, preventing complete filter plugging while managing fuel consumption strategically.
Solution Approach 2:
The system implements periodic active regeneration cycles based on monitored DPF soot load levels. Rather than continuous operation, the controller periodically injects additional fuel into the exhaust stream to raise temperatures and burn accumulated soot, then returns to normal operation. This periodic approach balances DPF maintenance with fuel economy.
2Speed
If throttling is used to control engine speed, then engine speed is regulated, but fuel amounts increase and PM production increases
Solution Approach 1:
The system changes operating parameters by adjusting engine speed and load settings to optimize the balance between throttling effectiveness and PM production. The controller monitors DPF soot load and adjusts engine operating parameters, including speed, torque, and fuel injection timing, to minimize PM generation while maintaining required vehicle performance.
Solution Approach 2:
The system dynamically adjusts engine operation based on real-time DPF soot load monitoring. Rather than fixed throttling strategies, the controller continuously adapts engine speed, torque demands, and fuel injection parameters based on current DPF conditions, vehicle speed, and driver demand to minimize PM production while maintaining control.
3Object-affected harmful factors
If the DPF is used to trap PM, then exhaust emissions are reduced, but the filter plugs up quickly and requires frequent regeneration
Solution Approach 1:
The system implements feedback control by continuously monitoring DPF differential pressure to estimate soot load accumulation. This feedback information is used by the controller to determine when active regeneration is needed and to adjust engine operating parameters to optimize DPF performance. The feedback loop enables proactive management of DPF soot load to extend service life while maintaining emission reduction effectiveness.
Solution Approach 2:
The system enables self-service by allowing the DPF to perform passive regeneration when exhaust temperatures are sufficient to burn off accumulated soot without additional fuel injection. The controller monitors DPF conditions and allows passive regeneration to occur naturally during high-load engine operation, reducing the need for active regeneration cycles and extending DPF service life.
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 the frequency of active regeneration cycles, increases opportunities for passive regeneration, and optimizes fuel economy by managing engine speed and transients, leading to improved DPF performance and reduced fuel consumption.
Implementation Method 1
a diesel oxidation catalyst (DOC) can be provided upstream of a DPF to oxidize NO to generate NO2 (requiring accurate control to maintain the mass ratio of NO/PM in engine-out exhaust gas), which in turn oxidizes the PM in the downstream DPF
Implementation Method 2
The filter is designed to collect PM while allowing exhaust gases to pass through it
Implementation Method 3
The regeneration process burns off or 'oxidizes' PM that has accumulated in the filter
Data Source
AI summary
This disclosure provides a method and system for determining recommendations for vehicle operation that reduce soot production in view of a diesel particulate filter (DPF) of an exhaust aftertreatment system. Recommendations generated can reduce excessive particulate matter (PM) production during transient engine events and provide for operating conditions favorable for passive regeneration. In this way, less frequent active regeneration of the DPF is needed and/or more opportunities are provided for passive regeneration. The system and method can utilize location and terrain information to anticipate and project a window of operation in view of reducing soot production and soot loading of the DPF, or provide the operator with instruction when such opportunities are present or will soon be encountered.