Exhaust Gas Temperature Control for Catalyst Warm-Up Without Overheating
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Solution Overview
Problem
Existing methods for rapidly increasing exhaust gas temperature to optimize catalytic converters often result in the internal temperature exceeding the predefined range, leading to degradation of catalytic components and reduced emission reduction capability.
Innovation Solution
A regulation method and device that control the exhaust gas temperature upstream of the catalyst by determining a second setpoint for air torque reserve, combined with a first setpoint, to maintain the catalyst within its optimal temperature range, using proportional regulation and lookup tables to adjust temperature differences and engine conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a reserve of air torque is added to rapidly increase exhaust gas temperature for catalyst activation, then the catalyst reaches optimal temperature faster, but the internal temperature of the catalyst may exceed the upper limit of its predefined temperature range causing degradation
Solution Approach 1:
The control unit continuously monitors the actual temperature of the catalyst and compares it with the target temperature. Based on this feedback, the control unit adjusts the reserve of air torque in real-time to maintain the catalyst temperature within the optimal range, preventing both insufficient heating and overheating that would cause degradation.
Solution Approach 2:
The system dynamically changes the parameter of reserve of air torque based on the catalyst's actual temperature state. By adjusting this parameter according to temperature feedback, the system achieves rapid heating when needed while preventing temperature from exceeding the upper limit, thus resolving the contradiction between heating speed and component durability.
2Productivity
If the exhaust gas temperature is increased rapidly to optimize catalyst function, then emission reduction efficiency improves, but the risk of catalytic component degradation increases
Solution Approach 1:
The control unit uses temperature feedback from the catalyst to regulate the reserve of air torque. This ensures that the exhaust gas temperature is increased sufficiently to optimize catalyst function and emission reduction, while simultaneously preventing temperature from rising to levels that would cause thermal degradation of catalytic components.
Solution Approach 2:
The system preemptively adjusts the reserve of air torque to cushion against potential temperature overshoot. By monitoring temperature trends and adjusting the heating rate in advance, the system prevents thermal degradation before it occurs, allowing aggressive heating when safe and conservative heating when approaching temperature limits.
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
Prevents excessive temperature increases, safeguarding catalytic components and maintaining emission reduction efficiency by ensuring the catalyst operates within its predefined temperature range.
Implementation Method 1
a first temperature of exhaust gases upstream of a catalyst is regulated according to a second setpoint in order to promote obtaining a second chosen temperature of the exhaust gases in the catalyst
Data Source
Figure 1
Figure 2~3
AI summary
A control method is implemented in a vehicle comprising a thermal engine whose operating speed is determined by a first setpoint representing a supply air torque, and which produces exhaust gases that feed a catalytic converter exhaust system. This method includes a step (10-30) in which a second setpoint is determined, representing a reserve of air torque intended to heat the catalytic converter and intended to be combined with the first setpoint, and a first exhaust gas temperature upstream of the catalytic converter is regulated according to this second setpoint to promote the achievement of a second chosen exhaust gas temperature in the catalytic converter.