Diesel Particulate Filter Soot Control via Dynamic Rate Limits
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Solution Overview
Problem
Existing methods for controlling soot in diesel particulate filters rely on threshold-based regeneration, which may not effectively manage soot levels in all situations, particularly when the filter is underloaded, leading to inadequate filtration performance and increased emissions.
Innovation Solution
A control system and method that calculates engine performance values based on candidate control points, determining a soot change rate and adjusting the soot change limit to maintain optimal soot levels in the filter, using sensor information and dynamic control maps to manage soot accumulation and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If threshold-based regeneration is used to control soot levels, then regeneration can be initiated when the filter is overloaded, but the method fails to effectively manage soot levels when the filter is underloaded, leading to inadequate filtration performance
Solution Approach 1:
The patent applies dynamics by transitioning from static threshold-based regeneration to dynamic control that continuously adjusts engine performance values based on real-time soot change rate calculations. The system dynamically evaluates multiple candidate control points and selects optimal operating points that adapt to current filter soot loading conditions, enabling effective management of both underloaded and overloaded states.
Solution Approach 2:
The patent implements parameter changes by calculating engine performance values including soot change rates from multiple candidate control points and comparing them against soot change rate limits. The system changes operating parameters (fuel injection timing, EGR rates, air-fuel ratio) to maintain soot levels within desired ranges, adjusting engine operation based on calculated soot accumulation or depletion rates rather than relying on fixed thresholds.
2Object-generated harmful factors
If the particulate filter operates with insufficient soot, then the filter structure remains clean, but filtration efficiency decreases and emissions increase
Solution Approach 1:
The patent applies feedback by continuously calculating soot change rates based on engine operating conditions and comparing them against desired soot change rate limits. The system uses this feedback to determine whether to accumulate soot (when filter is underloaded) or initiate regeneration (when filter is overloaded), creating a closed-loop control system that maintains optimal soot levels for both filtration performance and emissions control.
Solution Approach 2:
The patent implements preliminary action by proactively managing soot accumulation before the filter becomes overloaded or underloaded. The system calculates predicted soot change rates from candidate control points and takes preventive engine control actions to maintain soot levels within the optimal range, avoiding both excessive accumulation and insufficient loading 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
This approach improves filtration efficiency by dynamically controlling soot levels, optimizing filter performance, and reducing unwanted emissions by addressing underloaded conditions and maintaining optimal soot quantities in the diesel particulate filter.
Implementation Method 1
Aftertreatment devices, such as particulate filters, may be used in combination with internal combustion engines to assist in reducing soot emissions
Implementation Method 2
initiating a regeneration process in which the temperature of exhaust gas entering the filter is increased, thereby increasing the temperature of the particulate filter by an amount sufficient to burn off some of the soot
Data Source
AI summary
A method for controlling an internal combustion engine system including a particulate filter includes receiving a desired output for an internal combustion engine and receiving sensor information including information indicative of a quantity of soot in the particulate filter. The method includes calculating a plurality of sets of engine performance values based on respective sets of candidate control points, each set of engine performance values including a soot change rate at which the quantity of soot changes over time and determining whether the soot change rate satisfies a soot change rate limit that requires an increase in the quantity of soot in the particulate filter. The method also includes controlling the internal combustion engine based on a set of candidate control points that satisfies the soot change rate limit.