Gasoline Particulate Filter Regeneration via Differential Spark Timing
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Solution Overview
Problem
Internal combustion engine systems face inefficiencies due to particulate filter clogging, which increases backpressure and reduces engine efficiency, as existing regeneration methods may inadvertently raise intake gas temperatures when retarding spark timing in donor cylinders dedicated to exhaust gas recirculation systems.
Innovation Solution
A method involving differential spark timing retardation between donor and non-donor cylinders, where the spark timing of non-donor cylinders is retarded more than that of donor cylinders, with a portion of exhaust gas from donor cylinders directed to an exhaust gas recirculation system, to regenerate the particulate filter without increasing intake gas temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spark timing is retarded in donor cylinders to increase exhaust gas temperature for particulate filter regeneration, then regeneration effectiveness is improved, but intake gas temperature increases which reduces engine efficiency
Solution Approach 1:
The engine cylinders are segmented into donor cylinders (first set) and non-donor cylinders (second set). The particulate filter receives exhaust gas only from the non-donor cylinders, while donor cylinders provide exhaust gas to the EGR system. This segmentation allows independent control of spark timing for each group, enabling regeneration without raising intake gas temperature.
Solution Approach 2:
Different spark timing strategies are applied to different cylinder groups. Non-donor cylinders receive greater spark timing retardation to generate high-temperature exhaust for filter regeneration, while donor cylinders maintain normal or less-retarded timing to supply cool exhaust for EGR. This local differentiation resolves the contradiction between regeneration needs and intake temperature control.
2Reliability
If spark timing is retarded to regenerate the particulate filter, then exhaust gas temperature increases improving filter cleaning, but engine efficiency decreases
Solution Approach 1:
Cylinders are divided into donor and non-donor groups with different exhaust routing. Non-donor cylinders (exhaust to aftertreatment) undergo spark timing retardation for regeneration, while donor cylinders (exhaust to EGR) maintain normal timing. This preserves overall engine efficiency while achieving filter regeneration goals.
Solution Approach 2:
Spark timing retardation is applied locally only to non-donor cylinders where exhaust contributes to filter regeneration. Donor cylinders maintain optimal spark timing for efficient combustion. This localized approach achieves regeneration without sacrificing overall engine productivity.
3Ease of operation
If all cylinders are operated with the same spark timing, then engine operation is simplified, but regeneration effectiveness is reduced due to mixed exhaust temperatures
Solution Approach 1:
The engine control system segments cylinders into two groups with different spark timing strategies. Non-donor cylinders use retarded timing for high-temperature exhaust generation, while donor cylinders use normal timing. The exhaust systems are also segmented to route each group's exhaust to different destinations, enabling effective regeneration while maintaining manageable control complexity.
Solution Approach 2:
Different spark timing profiles are applied to different cylinder groups based on their exhaust routing function. This local differentiation optimizes regeneration effectiveness without requiring complex control of all cylinders individually, balancing simplicity and effectiveness.
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
Effectively regenerates the particulate filter by increasing exhaust gas temperature while minimizing the risk of elevated intake gas temperatures, thus maintaining engine efficiency and reliability.
Implementation Method 1
operating at least one donor cylinder and at least one non-donor cylinder of the internal combustion engine at a spark timing
Implementation Method 2
A proportion of exhaust gas generated by the at least one donor cylinder is provided to an exhaust gas recirculation system
Implementation Method 3
retarding the spark timing of the at least one non-donor cylinder by a first amount of retardation and retarding the spark timing of the at least one donor cylinder by a second amount of retardation
Data Source
AI summary
A internal combustion engine system includes a gasoline internal combustion engine having a set of donor cylinders and a set of non-donor cylinders. The donor cylinders provide a proportion of the exhaust gas to an exhaust gas recirculation system and the remainder of the exhaust gas to an exhaust gas aftertreatment system including a particulate filter. The non-donor cylinders also provide exhaust gas to exhaust gas aftertreatment system. An engine controller can determine whether the particulate filter needs regeneration, and in response, retard a spark timing of the non-donor cylinders by an amount that is different from an amount or retardation of the donor cylinders.