SCR Injection Controller Pattern Correction for Exhaust Purification
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Solution Overview
Problem
Conventional Selective Catalyst Reduction (SCR) systems in vehicle exhaust gas purification face efficiency deterioration and NH3 slip due to irregular catalyst performance patterns, leading to increased costs from requiring additional diagnostic apparatuses for accurate state measurement.
Innovation Solution
A control method for the SCR system that includes a NOx sensor, temperature sensor, and injection controller to continuously adjust the reducing agent injection based on normal and abnormal performance patterns, maintaining optimal purification efficiency without the need for additional diagnostic apparatuses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed quantity of reducing agents is supplied according to predetermined performance patterns, then the control system remains simple, but the purification efficiency deteriorates when catalyst performance changes irregularly
Solution Approach 1:
The patent implements a feedback mechanism where the actual purification efficiency is continuously monitored and compared with the predetermined performance pattern. When a deviation is detected, the system automatically adjusts the reducing agent injection amount to compensate for the irregular catalyst performance changes, thereby maintaining reliable purification efficiency without requiring complex additional diagnostic apparatus.
2Reliability
If additional diagnostic apparatuses are installed to accurately diagnose catalyst state, then the purification efficiency can be maintained, but the system cost increases excessively
Solution Approach 1:
The system uses existing sensors (NOx sensor and temperature sensor) to perform self-diagnosis of catalyst performance. By comparing the actual purification efficiency with the predetermined performance pattern, the system can detect irregular changes and automatically adjust the reducing agent injection amount, eliminating the need for additional expensive diagnostic apparatus while maintaining purification efficiency.
3Reliability
If the reducing agent injection amount is adjusted based on actual purification efficiency, then the purification efficiency is maintained, but the control complexity increases
Solution Approach 1:
The control operation automatically adjusts the reducing agent injection amount based on feedback from the NOx sensor and temperature sensor. The injection controller compares the actual purification efficiency with the predetermined performance pattern and automatically calculates the required injection amount adjustment, simplifying the control operation while maintaining purification efficiency.
Solution Approach 2:
The patent replaces complex manual control operations with an automated electronic control system. The injection controller electronically processes sensor data, compares it with stored performance patterns, and automatically adjusts the reducing agent injection amount, eliminating the need for complex manual calculations and adjustments.
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
Enhances SCR system performance by correcting reducing agent injection amounts, reducing costs, and maintaining optimal exhaust gas purification efficiency even with irregular catalyst performance changes, using conventional NOx sensors to classify abnormal patterns and adjust injection accordingly.
Implementation Method 1
reduce nitride oxide into nitrogen gas (N2) and water (H2O) as a catalytic reaction of nitride oxide and ammonia in the exhaust gas by an SCR catalyst
Implementation Method 2
convert a reducing agent (urea) injected in a stream direction of the exhaust gas through an injector into ammonia (NH3) by heat of the exhaust gas
Implementation Method 3
DOC oxidizes total hydrocarbons and carbon monoxide in the exhaust gas
Implementation Method 4
a NOx sensor measuring nitride oxide after actuation of the SCR
Implementation Method 5
a temperature sensor sensing a temperature of the SCR
Data Source
AI summary
A control method of an exhaust gas purification system for a vehicle may include: determining, by an injection controller, whether a selective catalyst reduction (SCR) is actuated; determining, by the injection controller, whether a temperature of the SCR is within a set diagnosis region; deciding, by the injection controller, a normal pattern of the SCR corresponding to the temperature of the SCR; comparing, by the injection controller, the decided normal pattern of the SCR with a current performance pattern of the SCR; determining, by the injection controller, whether a current performance pattern of the SCR is an abnormal pattern; and performing, by the injection controller, a correction control based on a current abnormal pattern of the SCR.