Engine Control Isochronous Regeneration

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Solution Overview

Problem

Exhaust gas purification devices in diesel engines face challenges with excessive particulate matter accumulation leading to reduced regeneration capacity and potential damage due to insufficient temperature increase during low-load operations, particularly when droop control is applied, resulting in reduced engine rotational speed and inadequate regeneration.

Innovation Solution

The engine device incorporates an engine control system that executes non-work regeneration control by maintaining a constant rotational speed through isochronous control, using post-injection and high rotational speeds to increase exhaust gas temperature, and includes modes like stationary and recovery regeneration control to ensure effective particulate matter combustion and purification capacity maintenance, even under low-load conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the engine rotational speed is limited during no load running to suppress fuel consumption or noise, then fuel consumption and noise are reduced, but the exhaust gas temperature cannot be sufficiently increased, leading to reduced regeneration capacity of the exhaust gas purification device

Engineering Contradiction:
Improvefuel consumptionVSAvoidregeneration capacity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The control device performs preliminary judgment to determine whether regeneration execution is permitted before attempting regeneration. This preliminary check prevents regeneration attempts when conditions are inadequate (low rotational speed, insufficient temperature), thereby avoiding damage while preserving the ability to regenerate when conditions are favorable.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the regeneration strategy based on real-time operating conditions. When rotational speed is limited during no-load operation, the control device determines that regeneration is not permitted, but when the engine operates at higher speeds or under load, regeneration becomes permitted. This dynamic adaptation resolves the contradiction between fuel efficiency and regeneration capacity.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If droop control is designated and regeneration control is executed, then the engine can operate under load, but the rotational speed is reduced, leading to reduced regeneration capacity of the exhaust gas purification device

Engineering Contradiction:
Improvecontrol mode flexibilityVSAvoidregeneration capacity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The control device dynamically evaluates whether regeneration is permitted based on the current control mode and rotational speed. Under droop control, the system monitors rotational speed and determines regeneration permission accordingly - allowing regeneration when speed is sufficient, preventing it when speed drops too low. This dynamic decision-making maintains both control flexibility and regeneration reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from rotational speed sensors and control mode detection to continuously assess whether regeneration conditions are met. The control device adjusts regeneration permission based on this feedback, ensuring that regeneration only occurs when the engine operational state supports adequate temperature and speed, thus preventing damage while maintaining adaptability.

Inventive Principle:
Principle #23Feedback

3Reliability

If unburned fuel is supplied into the exhaust gas purification device to increase temperature and facilitate regeneration, then regeneration is facilitated, but when PM is excessively accumulated, rapid combustion causes damages such as cracks and dissolved loss in the exhaust gas purification device

Engineering Contradiction:
Improveregeneration executionVSAvoiddevice damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control device performs a preliminary determination of whether regeneration execution is permitted by assessing current operating conditions (rotational speed, temperature, PM accumulation level) before injecting unburned fuel. This preliminary check ensures that fuel injection and subsequent rapid combustion only occur when the engine can maintain adequate rotational speed and temperature, preventing thermal shock and damage to the exhaust gas purification device while still enabling effective regeneration when conditions are appropriate.

Inventive Principle:
Principle #10Preliminary action

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 damage to the exhaust gas purification device, ensures effective regeneration, and maintains purification capacity by compulsorily maintaining high rotational speeds and temperatures, thereby avoiding excessive emissions and component deterioration.

Implementation Method 1

an exhaust gas purification device which is arranged in an exhaust path of the engine, and executes a plurality of regeneration controls with which particulate matter accumulated in the exhaust gas purification device is combusted and removed

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

particulate matter accumulated in the exhaust gas purification device is combusted and removed

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

the PM is combusted, which makes it possible to facilitate the regeneration of the exhaust gas purification device

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 4

unburned fuel is supplied into the exhaust gas purification device, and the PM is combusted

Methodology Applied
Scientific EffectCombustion heating: Combustion

Implementation Method 5

the temperature of the exhaust gas is increased, and the exhaust gas purification device is not sufficiently regenerated

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP3124762B1Engine device
Publication Date: 2020.01.08 YANMAR CO LTD
  • EP3124762B1 patent drawingFigure 1
  • EP3124762B1 patent drawingFigure 2
  • EP3124762B1 patent drawingFigure 3

AI summary

It is an object of the present invention to provide an engine device that can maintain the temperature of exhaust gas at a high temperature, combust and remove particulate matter when an exhaust gas purification device is regenerated. A work vehicle of the present invention includes an engine 5, an exhaust gas purification device 50 arranged on the exhaust path of the engine 5, and an engine control device 311 that controls drive of the engine 5. The engine control device 311 executes a plurality of regeneration controls with which the particulate matter accumulated in the exhaust gas purification device 50 is combusted and removed. The engine control device 311 drives the engine 5 so as to solely combust and remove the particulate matter in the non-work regeneration control out of the plurality of regeneration controls and compulsorily executes isochronous control in which the rotational speed of the engine 5 is maintained constant, irrespective of variation in load of the engine 5.