Exhaust Purification Control Device Oxygen Occlusion Management
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Solution Overview
Problem
Fuel cutting in engines with oxygen occludable catalysts can lead to excessive oxygen occlusion, reducing exhaust gas purification ability when the engine resumes operation, and existing solutions either increase fuel consumption or inadequately enhance fuel efficiency.
Innovation Solution
A controlling device that calculates oxygen occludability and sets a delay time for fuel cutting, preventing excessive oxygen occlusion by adjusting the fuel cutting timing based on catalyst age and oxygen concentration sensors, ensuring optimal air-fuel ratio maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fuel cutting is executed to enhance fuel efficiency, then fuel consumption is reduced, but excessive oxygen is occluded on the catalyst which lowers exhaust gas purification ability
Solution Approach 1:
The control device performs preliminary action by detecting oxygen concentration before fuel cutting is executed and predicting the amount of oxygen to be occluded on the catalyst. Based on this prediction, the control device determines whether to execute fuel cutting or adjust its duration, preventing excessive oxygen occlusion that would harm purification ability while still achieving fuel efficiency benefits.
Solution Approach 2:
The control device uses feedback from oxygen concentration sensors (upstream and downstream of the catalyst) to monitor the oxidation-reduction state of exhaust gas. This feedback information is used to adjust fuel cutting control in real-time, ensuring that oxygen occlusion on the catalyst remains within acceptable limits while maintaining fuel efficiency improvements.
2Reliability
If fuel cutting is not entirely carried out to prevent excessive oxygen occlusion, then exhaust gas purification ability is maintained, but fuel consumption increases
Solution Approach 1:
The control device changes parameters by dynamically adjusting fuel cutting duration and timing based on predicted oxygen occlusion amounts and real-time oxygen concentration measurements. This allows optimization of the balance between fuel efficiency and purification ability by precisely controlling when and how long fuel cutting occurs, rather than using fixed conservative limits.
Solution Approach 2:
The control device applies partial fuel cutting action by selectively executing fuel cutting only when predicted oxygen occlusion will not exceed acceptable thresholds. This partial application of fuel cutting maintains purification ability while still achieving fuel efficiency benefits in appropriate conditions.
3Loss of energy
If instant fuel cutting is executed to maximize fuel efficiency, then fuel consumption is reduced, but exhaust gas purification ability largely declines
Solution Approach 1:
The control device performs preliminary prediction of oxygen occlusion amounts before executing instant fuel cutting. By calculating the expected oxygen concentration changes and catalyst oxidation states in advance, the system can determine whether instant fuel cutting will cause harmful excessive oxygen occlusion, preventing purification ability decline while maintaining fuel efficiency gains.
Solution Approach 2:
The control device uses rapid feedback from oxygen concentration sensors to monitor exhaust gas composition during and after instant fuel cutting execution. This feedback mechanism allows the system to detect and correct oxygen occlusion issues in real-time, maintaining purification ability even during brief fuel cutting events.
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 enhances fuel efficiency by preventing excessive oxygen occlusion, maintaining exhaust gas purification ability, and reducing fuel consumption during coasting and deceleration.
Implementation Method 1
An oxygen occludable material is a promotor having characteristics that adsorbs oxygen under a lean atmosphere, and releases the oxygen occluded during lean running under a rich atmosphere
Implementation Method 2
The oxygen occluded on the oxygen occludable material is used in oxidization of hydrocarbon, carbon monoxide, and hydrogen
Data Source
Figure 1
Figure 2(A)~2(C)
Figure 3~4
AI summary
A controlling device for purifying exhaust gas includes: a fuel cutting controller (2) that, if a predetermined condition for fuel cutting is satisfied, shuts off supply of fuel to an engine (10) after a predetermined delay time (B) elapses; a calculator (3) that calculates oxygen occludability of a catalyst (6, 7) being interposed in an exhaust system of the engine (10) and containing an oxygen occludable material; and a setter (4) that sets a length of the delay time (B) in accordance with the oxygen occludability calculated by the calculator (3).