DPF Regeneration Inhibition via Driver Switch Control
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Solution Overview
Problem
Existing diesel particulate filter (DPF) regeneration strategies, both active and passive, may not be suitable for all operating conditions of diesel engines, particularly when the vehicle is parked, leading to inefficient regeneration and potential impact on vehicle driveability.
Innovation Solution
A system and method that allows drivers to selectively inhibit or terminate DPF regeneration strategies using input devices such as switches in the instrument panel, enabling control over regeneration initiation and termination, thereby managing regeneration based on specific conditions like vehicle operation and DPF loading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DPF regeneration is initiated automatically under all conditions, then particulate trapping efficiency is maintained, but vehicle driveability is degraded during unsuitable operating conditions
Solution Approach 1:
The system dynamically adjusts the regeneration strategy based on real-time operating conditions. The controller monitors vehicle speed, engine load, and DPF soot loading to determine whether to initiate active regeneration, passive regeneration, or inhibit regeneration entirely. This dynamic decision-making process resolves the contradiction by adapting the regeneration behavior to match current operational requirements.
Solution Approach 2:
The system changes key parameters such as exhaust gas temperature, oxygen concentration, and nitrogen dioxide concentration based on operating conditions. During active regeneration, exhaust temperature is elevated to burn off particulates. During passive regeneration, nitrogen dioxide concentration is increased while maintaining lower temperatures. These parameter changes enable the system to maintain particulate trapping efficiency while avoiding driveability issues.
2Reliability
If active regeneration is used to maintain DPF effectiveness, then particulate accumulation is removed, but exhaust gas temperature must be elevated which may not be appropriate for all operating conditions
Solution Approach 1:
The invention segments the regeneration process into two distinct strategies: active regeneration and passive regeneration. Active regeneration uses high-temperature oxidation to remove particulates, while passive regeneration uses lower-temperature nitrogen dioxide-based oxidation. This segmentation allows the system to select the appropriate regeneration method based on operating conditions, avoiding unnecessary high-temperature events that could degrade driveability.
Solution Approach 2:
The invention introduces nitrogen dioxide as an intermediary substance for passive regeneration. Instead of directly using high-temperature oxidation, the system generates nitrogen dioxide through selective catalytic reduction and uses it to oxidize trapped particulates at lower temperatures. This intermediary approach enables effective regeneration without the adverse effects of high exhaust gas temperatures.
3Stability of the object's composition
If passive regeneration is locked out during active regeneration, then regeneration strategy stability is maintained, but flexibility is reduced when drivers need to control regeneration events
Solution Approach 1:
The system dynamically adjusts the locking mechanism between active and passive regeneration strategies. During active regeneration, passive regeneration is locked out to maintain stability. However, the system provides driver controls that can override this locking and initiate passive regeneration when needed, such as during idle or low-speed operation. This dynamic approach maintains strategy stability while providing necessary flexibility.
Solution Approach 2:
The system incorporates driver feedback through manual controls that allow the driver to request passive regeneration. The controller monitors driver inputs and system conditions to determine whether to honor the request or maintain the automatic locking strategy. This feedback mechanism enables the system to adapt between stability and flexibility based on driver needs and operational conditions.
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
Enables flexible control over DPF regeneration, preventing unnecessary regeneration events and maintaining DPF effectiveness by allowing drivers to manage regeneration strategies according to vehicle operation and DPF loading, thus optimizing regeneration conditions.
Implementation Method 1
a diesel oxidation catalyst (DOC) associated with a diesel particulate filter (DPF). The combination of these two exhaust gas treatment devices promotes chemical reactions in exhaust gas
Implementation Method 2
traps diesel particulate matter (DPM) as exhaust flows through the exhaust system from the engine
Implementation Method 3
Regeneration involves creating conditions that will burn off trapped particulates whose unchecked accumulation would otherwise impair DPF effectiveness
Data Source
AI summary
A system and method for initiation and control of passive regeneration (38) of a diesel particulate filter (34), and the integration of that regeneration strategy with an active regeneration strategy (36) and a strategy (40, 40A) for inhibiting passive regeneration. Passive regeneration can be initiated by driver actuation of an instrument panel device, such as a switch, while the vehicle is parked with the engine idling provided that certain conditions confirming that the vehicle is parked and the engine is at proper temperature are satisfied. Regeneration is inhibited by driver actuation of another switch for a maximum amount of time that may be shorter, or even prevented if DPF loading is too high.