Exhaust Additive Supply Correction via Sensor Feedback
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Solution Overview
Problem
Existing exhaust gas purification systems face challenges in accurately supplying additives to combustion engine exhaust streams, leading to potential excess or deficiency of substances like nitrogen oxides, which can result in undesired emissions and regulatory violations, especially when relying on calculation models for substance estimation rather than precise sensor measurements.
Innovation Solution
A method that corrects the estimation of substances in the exhaust gas stream using a calculation model instead of directly correcting the additive supply, ensuring the additive amount corresponds to the anticipated need, thereby reducing the risk of excessive or insufficient emissions by adjusting the supply based on altered substance estimates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a calculation model is used to estimate the presence of substances in the exhaust gas stream, then the system complexity is reduced and no additional sensors are required, but the measurement precision and reliability of substance estimation deteriorate
Solution Approach 1:
The system uses feedback from the downstream sensor measurement to correct the calculation model estimation. The correction factor is determined by comparing the estimated substance presence with the actual sensor measurement, and this correction factor is then applied to improve future estimations, creating a continuous improvement loop that maintains system simplicity while enhancing precision.
Solution Approach 2:
Instead of directly measuring substance presence with expensive sensors throughout the system, the invention creates a virtual copy of the sensor measurement through the calculation model. The model replicates sensor functionality using alternative data sources (exhaust gas parameters, engine parameters), and this virtual measurement is then corrected using actual sensor feedback to improve accuracy.
2Reliability
If the additive supply amount is increased to ensure sufficient reduction of nitrogen oxides, then the reliability of emission compliance is improved, but the risk of undesired emissions from excess additive increases
Solution Approach 1:
The system continuously monitors the actual substance presence using downstream sensors and compares it with model-based predictions. This feedback loop enables real-time adjustment of the additive supply rate, ensuring that sufficient additive is provided to meet emission compliance requirements while avoiding excessive additive injection that would create undesired emissions.
Solution Approach 2:
The system dynamically adjusts the additive supply parameter based on changing exhaust gas conditions, engine load, and corrected substance presence estimates. By continuously optimizing the additive supply rate rather than using fixed injection amounts, the system maintains reliable emission compliance across varying operating conditions while minimizing excess additive usage.
3Manufacturing precision
If the additive supply is adjusted frequently to match changing exhaust gas conditions, then the manufacturing precision of emission treatment is improved, but the complexity of control systems increases
Solution Approach 1:
The invention uses a calculation model that copies sensor functionality to estimate substance presence without requiring additional physical sensors. The model processes existing exhaust gas and engine parameters to generate corrected substance presence estimates, enabling precise additive supply adjustment through software-based control rather than complex hardware modifications.
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 improves the precision of additive supply, minimizing the risk of undesired emissions and ensuring compliance with emission limits by accurately adjusting the additive amount according to changing conversion rates and conditions, even when using calculation models for substance estimation.
Implementation Method 1
the additive reacts with one or more substances present in the exhaust gas stream so as to thereby form less hazardous substances
Implementation Method 2
SCR catalytic converters use ammonia (NH3) or a compound from which ammonia can be generated/formed as an additive to reduce the level of nitrogen oxides NOx
Data Source
AI summary
The present invention concerns a method in connection with the supplying of a first additive for treating an exhaust gas stream resulting from combustion in a combustion engine, wherein said first additive is supplied to said exhaust gas stream, and wherein said first additive is utilized for the reduction of at least a first substance (such as NOx) present in said exhaust gas stream, wherein the method comprises: estimation of a reduction of said first substance based on a first measurement of a presence of said first substance in said exhaust gas stream downstream of said supply of said first additive, and a second measurement of a presence of said first substance in said exhaust gas stream upstream of said supply of additive, comparison of said estimated reduction to a first reduction, and correction of the estimation of said second measurement of said first substance based on said comparison.