Deceleration Fuel Cutoff Regeneration for Gas Particulate Filter

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Solution Overview

Problem

In hybrid propulsion systems, passive regeneration of gas particulate filters (GPFs) is insufficient due to intermittent engine operation, leading to the need for active regeneration cycles, which are undesirable and result in increased emissions certification factors.

Innovation Solution

A powertrain system that includes a controller to monitor GPF loading and temperature, initiating deceleration fuel cutoff (DFCO) to warm up the GPF passively during normal drive cycles, using the engine as an air pump without fuel to burn off particulate matter, thereby avoiding active regeneration and the associated emissions uplift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If passive regeneration is used in hybrid propulsion systems, then the engine operates intermittently and shutdowns occur, but regeneration is insufficient and filter cleanliness deteriorates

Engineering Contradiction:

Improveregeneration effectivenessVSAvoidfilter cleanliness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary warming up of the GPF before regeneration is needed, storing thermal energy in the filter. This preliminary heating action ensures that when regeneration is initiated, the GPF is already at the required temperature for effective particulate burn-off, resolving the insufficiency of passive regeneration in hybrid systems with intermittent engine operation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements periodic regeneration cycles by monitoring GPF loading and temperature, initiating regeneration at optimal intervals rather than continuously. This periodic action maintains filter cleanliness while accommodating the intermittent operation characteristics of hybrid propulsion systems

Inventive Principle:

Principle #19Periodic action

2Reliability

If active regeneration cycle is initiated, then filter cleanliness is restored, but vehicle operates outside normal drive cycle and emissions certification factor increases

Engineering Contradiction:

Improvefilter cleanlinessVSAvoidemissions certification factor

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system changes operating parameters by using deceleration fuel cutoff (DFCO) conditions to create the necessary temperature and oxygen environment for regeneration. By utilizing existing deceleration events and adjusting fuel injection parameters during these events, the system achieves regeneration without requiring invasive operational changes or operating outside the normal drive cycle, thus avoiding Ki factor application

Inventive Principle:

Principle #35Parameter changes

3Productivity

If deceleration fuel cutoff is used for regeneration, then passive regeneration is enabled during normal drive cycles, but engine must operate as air pump without fuel

Engineering Contradiction:

Improveregeneration capabilityVSAvoidengine operation mode

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The system uses the engine's own deceleration events and existing airflow to perform regeneration. During DFCO conditions, the engine naturally becomes an air pump, and the system leverages this self-generated airflow and thermal conditions to burn off particulates, requiring no external assistance or complex additional mechanisms

Inventive Principle:

Principle #25Self-service

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 passive GPF regeneration during normal driving cycles, avoiding the need for active regeneration cycles and reducing emissions certification factors, effectively maintaining filter cleanliness without invasive operational changes.

Implementation Method 1

The GPF may include a housing containing a multiple passageway substrate/media that captures particles as the exhaust gas passes through

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

The substrate/media is regenerated to remove built-up particles such as by subjecting the unit to conditions, including temperatures and gas compositions, to burn off the particles

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 3

A temperature sensor is configured to monitor a temperature of the gas particulate filter

Methodology Applied

Scientific EffectThermal detection: Thermocouple

Data Source

PatentUS11624303B1Deceleration fuel cut-off enabled regeneration for gas particulate filter

Publication Date: 2023.04.11 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

Systems and methods provide deceleration fuel cutoff regeneration of a gas particulate filter. A powertrain system includes an exhaust system containing the gas particulate filter, which is configured to collect particulate matter from an exhaust gas stream of the powertrain system. A temperature sensor is configured to monitor a temperature of the gas particulate filter. A loading monitor, such as a sensor and/or a model, is configured to provide a loading input of particulate loading of the gas particulate filter. At least one controller is configured to: determine, by comparing the loading input to stored values, whether the gas particulate filter requires the regeneration; effect a warmup of the gas particulate filter when the determination shows the gas particulate filter requires the regeneration; and initiate the regeneration when a value received from the temperature sensor meets a minimum threshold level.