Driving System Catalyst Emission Control
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Solution Overview
Problem
The service life of catalyst elements in exhaust gas purifying devices for internal combustion engines results in a decrease in catalytic conversion rates, leading to excessive nitrogen dioxide emissions as the catalyst ages, due to thermal aging and chemical interactions with lubricants and fuels, causing surplus nitrogen dioxide to be discharged into the environment.
Innovation Solution
Adjusting the nitrogen monoxide emission and exhaust gas temperature upstream from the catalyst element based on the instantaneous conversion rate and age of the catalyst to maintain a minimum nitrogen dioxide concentration and predetermined molar ratio between nitrogen monoxide and nitrogen dioxide, thereby compensating for the age-related decrease in conversion rate and optimizing nitrogen dioxide production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the catalyst element is configured to achieve a minimum conversion rate over its entire service life, then the catalytic performance is maintained, but the nitrogen dioxide concentration becomes excessively high at the beginning of service life, leading to increased emissions
Solution Approach 1:
The patent applies dynamics by making the nitrogen monoxide emission and exhaust gas temperature adjustable based on the catalyst's age. The control system dynamically modifies operating parameters (injection timing, charging pressure, valve actuation) as a function of the instantaneous conversion rate and catalyst age, transitioning from static to dynamic operation to optimize both conversion rate maintenance and emission reduction throughout the service life
Solution Approach 2:
The patent changes physical and chemical parameters of the exhaust gas by adjusting nitrogen monoxide emission and exhaust gas temperature upstream from the catalyst. By modifying these parameters based on catalyst age and instantaneous conversion rate, the system maintains adequate nitrogen dioxide concentration for particle filter regeneration while reducing excess nitrogen dioxide emissions to the environment
2Quantity of substance
If the nitrogen monoxide emission is increased to compensate for aging catalyst, then the nitrogen dioxide concentration is maintained, but the excess nitrogen dioxide may still be discharged to the environment
Solution Approach 1:
The patent implements feedback control by continuously monitoring the instantaneous conversion rate and catalyst age, then using this information to adjust nitrogen monoxide emission and exhaust gas temperature parameters. This closed-loop feedback system ensures that nitrogen dioxide concentration is maintained at adequate levels while preventing excessive discharge by adapting parameters in real-time based on actual catalyst performance
Solution Approach 2:
The patent applies preliminary action by pre-determining the relationship between catalyst age, instantaneous conversion rate, and optimal operating parameters. The control system uses predetermined adjustment strategies based on catalyst age to proactively maintain nitrogen dioxide concentration before it becomes insufficient, while avoiding excessive nitrogen dioxide production that would lead to harmful emissions
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 ensures a consistent and reduced nitrogen dioxide emission over the catalyst's service life, preventing excessive discharge and maintaining effective catalytic performance by adjusting operating parameters such as injection timing, charging pressure, and valve actuation to maintain optimal nitrogen dioxide levels for particle filter regeneration and selective catalytic reduction reactions.
Implementation Method 1
the at least one catalyst element serves to convert nitrogen monoxide catalytically to nitrogen dioxide, wherein this takes place at the determined conversion rate
Implementation Method 2
The exhaust gas produced by the internal combustion engine
Data Source
AI summary
A method for operating a driving system having an internal combustion engine and an exhaust gas purifying device through which exhaust gas from the internal combustion engine flows in order to be purified. The exhaust gas purifying device has at least one catalyst element for catalytic conversion of nitrogen monoxide into nitrogen dioxide at a determined conversion rate. In order to compensate for an age related decrease in the conversion rate of the catalyst element the nitrogen monoxide emission from the internal combustion engine and/or the exhaust gas temperature before the catalyst element are adjusted as a function of the current conversion rate and/or the age of the catalyst element so that the nitrogen dioxide concentration after the catalyst element is greater than or equal to a minimum concentration and/or that the molar ratio between nitrogen monoxide and nitrogen dioxide after the catalyst element corresponds to a predetermined ratio.