Exhaust Purification System SOx Regeneration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When SOx purging is executed at high engine speeds or with high fuel injection amounts, there is a risk of excessive catalyst temperature increase and deteriorated fuel consumption, particularly during the resumption of SOx purging operations.
Innovation Solution
The system employs a NOx reduction catalyst with catalyst regeneration means to increase exhaust gas temperature for SOx desorption, prohibition means to prevent excessive regeneration, and temperature retention control to maintain a lower catalyst temperature, using injection system control to manage fuel injection amounts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SOx purging is executed by increasing fuel injection amount to raise exhaust gas temperature, then SOx desorption and catalyst regeneration is achieved, but excessive catalyst temperature increase and deteriorated fuel consumption occur
Solution Approach 1:
The system dynamically adjusts the fuel injection amount based on real-time catalyst temperature feedback. The ECU monitors exhaust gas temperature and modifies the post-injection fuel quantity to maintain catalyst temperature within the optimal range for SOx desorption, preventing both insufficient regeneration and excessive temperature rise that would waste fuel
Solution Approach 2:
The system implements a closed-loop control where the ECU receives temperature signals from exhaust gas temperature sensors, processes this information, and adjusts the fuel injection amount accordingly. This feedback mechanism ensures that fuel is injected only to the extent necessary for SOx desorption, avoiding unnecessary fuel consumption while maintaining effective catalyst regeneration
2Productivity
If catalyst regeneration is executed at high engine speeds with high fuel injection amounts, then SOx purging capability is improved, but excessive temperature increase and fuel consumption deterioration occur particularly during resumption
Solution Approach 1:
The system employs periodic post-injection of unburned fuel into the exhaust gas at specific engine cycles to gradually raise the catalyst temperature to the SOx desorption range. This periodic heating approach, rather than continuous high-fuel injection, allows temperature to increase in controlled steps, achieving effective SOx purging while preventing excessive temperature spikes
Solution Approach 2:
The system changes the timing and quantity parameters of fuel injection based on engine operating conditions. During catalyst regeneration, the ECU adjusts the post-injection timing and fuel amount to optimize temperature rise rate, ensuring that SOx desorption occurs efficiently without causing excessive temperature increase that would harm the catalyst or waste fuel
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 effectively prevents excessive catalyst temperature increases and reduces fuel consumption during SOx purging resumption by controlling the catalyst temperature and optimizing fuel injection.
Implementation Method 1
the oxidation catalyst 31, a NOx storage reduction catalyst 32... supplied with unburned fuel through a post injection by the exhaust pipe injector 34 or the injectors 11, the oxidation catalyst 31 oxidizes the unburned fuel to increase the temperature of exhaust gas
Implementation Method 2
restoring the NOx storage reduction catalyst 32 from sulfur poisoning by increasing a temperature of the exhaust gas to a predetermined first target temperature at which sulfur oxides are desorbed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An exhaust purification system includes a NOx reduction catalyst 32 which is provided on an exhaust passage 13 of an internal combustion engine 10, a SOx purging control module 60 for executing a SOx purging control for restoring the NOx reduction catalyst 32 from sulfur poisoning by increasing a temperature of the exhaust gas to a first target temperature at which SOx are desorbed through an injection system control to increase a fuel injection amount, a prohibition module 70 for prohibiting an execution of the SOx purging control according to an operating state of the internal combustion engine 10, and a temperature retention mode control module 71 for executing a temperature retention mode control for maintaining the temperature of the exhaust gas at a second target temperature which is lower than the first target temperature by controlling the fuel injection amount during a period of time during which the SOx purging control is prohibited.