Diesel Particulate Filter Regeneration Control
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Solution Overview
Problem
The automatic regeneration of diesel engine particulate filters can lead to lubricating oil dilution due to delayed fuel injections, which reduces engine efficiency and requires frequent manual interventions, especially during low-load conditions and short driving missions, causing prolonged regeneration times and oil quality issues.
Innovation Solution
Implementing a system that inhibits automatic regeneration and triggers a manual regeneration mode when critical conditions are met, such as excessive unfavourable events, insufficient lubricating oil quality, or resistance in the exhaust system, allowing the driver to initiate manual regeneration under specific conditions, thereby preventing oil dilution and maintaining engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If automatic regeneration is continuously performed using delayed POST injections to reach light-off temperature, then particulate filter regeneration is achieved, but lubricating oil dilution increases and oil quality deteriorates
Solution Approach 1:
The system dynamically adjusts the regeneration strategy based on real-time monitoring of unfavourable events and oil quality parameters. The control unit switches between automatic regeneration mode and manual regeneration mode depending on current operating conditions, preventing oil dilution while ensuring filter regeneration when appropriate
Solution Approach 2:
The system implements feedback control by monitoring multiple parameters including unfavourable events counter, oil temperature, engine load, and RPM. Based on this feedback, the control unit determines whether to inhibit automatic regeneration or allow it to proceed, thereby preventing oil dilution while maintaining filter regeneration capability
2Temperature
If delayed POST injections are used to enrich unburnt hydrocarbons for oxidation, then light-off temperature is achieved, but fuel penetration into lubricating oil film increases
Solution Approach 1:
The system performs preliminary assessment of operating conditions by counting unfavourable events and monitoring oil quality before initiating regeneration. By evaluating conditions in advance, the system prevents fuel injection into the oil film under problematic conditions, avoiding oil contamination while still achieving necessary temperature when appropriate
Solution Approach 2:
The system changes operational parameters by switching between different regeneration modes (automatic vs manual) and adjusting injection timing based on monitored conditions. This parameter adjustment prevents fuel-oil contact under unfavorable conditions while maintaining effective regeneration when conditions are suitable
3Object-affected harmful factors
If automatic regeneration is inhibited during critical conditions, then lubricating oil quality is protected, but particulate filter regeneration is delayed
Solution Approach 1:
The system provides self-service by monitoring its own operating conditions and automatically determining when regeneration should occur. The control unit manages the regeneration process based on real-time feedback, ensuring oil protection while enabling timely filter regeneration without requiring external intervention
4Reliability
If multiple POST injections are used to ensure light-off temperature during low load conditions, then regeneration effectiveness is improved, but oil dilution and regeneration duration increase
Solution Approach 1:
The system applies partial action by selectively enabling POST injections only when operating conditions are favorable. Rather than continuously applying maximum regeneration effort, the system monitors conditions and activates regeneration only when it will be effective and harmful to the oil, reducing unnecessary regeneration duration
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 prevents lubricating oil dilution and extends the life of the oil by allowing controlled manual regeneration, ensuring efficient particulate filter cleaning and maintaining engine efficiency without the need for frequent oil changes.
Implementation Method 1
The aforesaid trap is integrated in the exhaust line of the engine and is able to withhold inside it the particulate generated during the process of combustion... a particulate filter or trap... The presence of an oxidizing catalytic devices set along the exhaust line of the engine... precatalyser 11, the catalytic converter 12
Implementation Method 2
an electromagnetic fuel injector 2 controlled by an electronic control unit 3... in addition to the main pulse 'MAIN' and to a pulse 'PRE' that precedes the main pulse and a pulse 'PILOT', the control unit is also able to send one or more delayed injection pulses 'AFTER' and 'POST'
Implementation Method 3
In order to activate the combustion of the particulate, without resorting to the use of chemical catalysts mixed to the fuel, the temperature of the burnt gases at the inlet of the trap must be brought to at least 600°C... by adequately calibrating the main engine parameters and using one or more injections of a 'POST' type, with the purpose of enriching the flow of the gas of unburnt hydrocarbons
Implementation Method 4
The reference number 9 designates as a whole the exhaust line of the engine, set in which are the turbine 10... A sensor 15 detects the difference in pressure existing between upstream and downstream of the system for treatment of the exhaust gases... the line for exhaust-gas recirculation from the outlet of the engine to the EGR valve 7
Data Source
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AI summary
In a diesel engine equipped with a system for automatic regeneration of the particulate filter, the automatic regeneration mode is inhibited in the case where there is recorded a number higher than a pre-set threshold of unfavourable events, i.e., of interruptions of the automatic-regeneration step before its completion, and/or in the case where an insufficient quality of the engine lubricating oil is detected due to a dilution in the oil of fuel injected with the delayed injections that are necessary for regenerating the filter. When the automatic regeneration mode is inhibited, an on-demand regeneration mode is simultaneously enabled, which can be activated manually by the driver. The system checks in this case that on-demand regeneration is performed before the vehicle has covered a certain mileage since the automatic regeneration mode was inhibited. Otherwise, the vehicle is set in a condition of limited performance, to induce the driver to execute the manual regeneration mode. If this is not carried out before a further mileage is covered, also manual regeneration is inhibited, rendering regeneration possible only in a repair shop.