SCR Catalyst Additive Control via Road Surface Temperature Estimation
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Solution Overview
Problem
Existing methods for controlling the supply of additives to catalytic exhaust cleaning systems, such as SCR catalysts, face challenges in managing ammonia storage and release due to temperature fluctuations, leading to undesirable emissions and inefficiencies in nitrogen oxide reduction.
Innovation Solution
A method that estimates the expected temperature situation of the exhaust flow based on the vehicle's running surface data, allowing for controlled adjustment of additive supply to optimize storage capacity and prevent ammonia discharge, by adjusting the amount of additive injected and engine parameters like injection times and ancillary usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine operates with greater efficiency and lower fuel consumption, then fuel economy is improved, but nitrogen oxide discharges increase requiring greater exhaust cleaning
Solution Approach 1:
The control system performs preliminary action by estimating the expected temperature situation in advance based on running surface data before the temperature change occurs. This allows the additive supply to be adjusted proactively to prevent ammonia discharge when temperature increases are anticipated, while still enabling efficient engine operation at lower fuel consumption levels.
2Quantity of substance
If larger amounts of ammonia are stored in the catalyst at lower temperatures, then nitrogen oxide reduction capacity is improved, but ammonia discharge risk increases when temperature rises suddenly
Solution Approach 1:
The system estimates the expected temperature situation in advance based on running surface data and adjusts the additive supply accordingly before the temperature change occurs. This preliminary action allows maximizing ammonia storage when low temperatures are expected while preventing ammonia discharge when temperature increases are anticipated, by modulating the additive supply rate in advance.
Solution Approach 2:
The control system continuously monitors the actual temperature situation and compares it with the estimated temperature situation. Based on this feedback and the deviation between expected and actual conditions, the system adjusts the additive supply rate dynamically to maintain optimal ammonia storage levels while preventing discharge, resolving the contradiction between storage capacity and discharge risk.
3Productivity
If the catalyst storage capacity is maximized, then nitrogen oxide cleaning effectiveness is improved, but control precision during temperature fluctuations deteriorates
Solution Approach 1:
By estimating the expected temperature situation in advance based on running surface data, the system performs preliminary adjustment of the additive supply rate before temperature fluctuations occur. This allows the catalyst storage capacity to be maximized for optimal nitrogen oxide cleaning effectiveness while maintaining precise control of additive supply to prevent ammonia discharge during anticipated temperature changes.
Solution Approach 2:
The system continuously compares the actual temperature situation with the estimated temperature situation and adjusts the additive supply rate based on the deviation. This feedback mechanism maintains precise control of additive supply even when the catalyst storage capacity is maximized, ensuring both high nitrogen oxide reduction efficiency and precise control during temperature fluctuations.
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 enables more efficient fuel economy by storing sufficient ammonia at lower temperatures while minimizing the risk of ammonia discharge during temperature increases, ensuring compliance with emission regulations and enhancing the effectiveness of the SCR catalyst process.
Implementation Method 1
The additive supplied to the catalyst is adsorbed (stored) in the catalyst, whereupon nitrogen oxides in the exhaust gases react with the ammonia stored in the catalyst
Implementation Method 2
nitrogen oxides in the exhaust gases react with the ammonia stored in the catalyst to reduce nitrogen oxides (substantially to nitrogen gas and water vapour)
Data Source
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AI summary
The present invention relates to a method for supply of additive to a catalytic exhaust cleaning process for cleaning of an exhaust flow from a combustion engine of a vehicle, which vehicle comprises control means for control of supply of said additive to said exhaust flow. The method comprises estimating an expected temperature situation for said exhaust cleaning process on the basis of a representation of the vehicle's running surface, and controlling said supply of additive on the basis of said estimated temperature situation.