Exhaust Catalyst Oxygen Control with Poisoning Compensation

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Solution Overview

Problem

In internal combustion engines with oxygen storage catalysts, the amount of catalyst poisoning is not considered during oxygen supply control, leading to deviations in oxygen storage amounts, which negatively impact exhaust emission performance.

Innovation Solution

An exhaust purification system that includes a catalyst for oxygen storage, with components to calculate oxygen storage and poisoning amounts, and an oxygen control mechanism to adjust oxygen supply based on these calculations, ensuring optimal oxygen storage and minimizing poisoning effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the oxygen storage amount of the catalyst is controlled by adjusting the throttle valve opening degree, then the exhaust purification performance is enhanced, but the catalyst poisoning amount is not considered leading to deviation from suitable oxygen storage values

Engineering Contradiction:

Improveexhaust purification performanceVSAvoidoxygen storage amount control accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The control system calculates the catalyst poisoning amount based on accumulated rich exhaust gas exposure and uses this feedback to adjust the target oxygen storage amount. When poisoning is detected, the system modifies the target oxygen storage amount to account for the reduced catalyst capacity, ensuring more accurate control despite the poisoning effect.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system proactively calculates and monitors the poisoning amount before it causes significant deterioration in exhaust purification performance. By predicting the poisoning level based on historical rich exhaust exposure, the system can preemptively adjust control parameters to maintain optimal oxygen storage levels.

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If the catalyst is exposed to rich exhaust gas to restore oxygen storage, then the oxygen storage amount increases, but the catalyst poisoning increases

Engineering Contradiction:

Improveoxygen storage amountVSAvoidcatalyst poisoning

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The system dynamically changes the target oxygen storage amount parameter based on the calculated poisoning level. When poisoning is detected, the target oxygen storage amount is adjusted upward to compensate for the reduced catalyst capacity, while the actual oxygen storage is controlled through throttle adjustments. This parameter adaptation allows the system to maintain effective oxygen storage despite accumulated poisoning.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the oxygen storage amount is increased to compensate for poisoning, then the exhaust purification performance is maintained, but the amount of oxygen supply increases

Engineering Contradiction:

Improveexhaust purification performanceVSAvoidoxygen supply amount

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system applies partial compensation for poisoning by adjusting the target oxygen storage amount based on the calculated poisoning level, rather than fully compensating to original levels. This partial action approach maintains adequate exhaust purification performance while avoiding excessive oxygen supply that would occur with full compensation, thus balancing performance requirements with energy efficiency.

Inventive Principle:

Principle #16Partial or excessive 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 system improves exhaust emission control by maintaining suitable oxygen storage levels and reducing catalyst poisoning, thereby enhancing the overall exhaust purification performance.

Implementation Method 1

a catalyst arranged in an exhaust passage of an internal combustion engine and able to store oxygen

Methodology Applied

Scientific EffectOxygen storage: Absorption (physical)

Implementation Method 2

a poisoning amount calculating part configured to calculate a poisoning amount of the catalyst

Methodology Applied

Scientific EffectCatalyst poisoning: Adsorption

Data Source

PatentUS11143128B2Exhaust purification system of internal combustion engine

Publication Date: 2021.10.12 TOYOTA JIDOSHA KK

AI summary

An exhaust purification system of an internal combustion engine includes a catalyst arranged in an exhaust passage of the internal combustion engine and able to store oxygen, a storage amount calculating part configured to calculate an oxygen storage amount of the catalyst, a poisoning amount calculating part configured to calculate a poisoning amount of the catalyst, and an oxygen amount control part configured to control an amount of oxygen supplied to the catalyst based on the oxygen storage amount and the poisoning amount.