EGR Control Using Catalyst Efficiency Feedback
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Solution Overview
Problem
Existing methods for controlling supercharged internal combustion engines with dual EGR circuits fail to optimize emissions reduction, as they do not account for the efficiency of the catalyst, leading to unnecessary fuel consumption and incomplete combustion risks.
Innovation Solution
A method that determines the proportion of EGR gas recirculation based on the efficiency of the oxidation catalyst, using a sliding average of catalyst efficiency over time to adjust EGR flow rates, ensuring optimal emissions treatment and minimizing fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the low-pressure EGR circuit is used to reduce CO2 emissions, then fuel consumption is improved, but HC and CO emissions increase due to incomplete combustion
Solution Approach 1:
The control method uses feedback from the catalyst efficiency signal to dynamically adjust the EGR circuit selection. The catalyst efficiency is continuously monitored and fed back to the control unit, which then adapts the EGR strategy accordingly, transforming the previously open-loop precautionary approach into a closed-loop optimized system.
Solution Approach 2:
The system transitions from a static, conservative EGR strategy to a dynamic one that adapts to real-time catalyst conditions. The control unit dynamically switches between high-pressure and low-pressure EGR circuits based on the current catalyst efficiency, allowing the system to optimize fuel consumption when the catalyst is efficient and prevent incomplete combustion when it is not.
2Object-generated harmful factors
If the high-pressure EGR circuit is used to prevent incomplete combustion, then HC and CO emissions are reduced, but CO2 emissions and fuel consumption increase
Solution Approach 1:
The system dynamically selects between high-pressure and low-pressure EGR circuits based on real-time catalyst efficiency measurements, replacing the static conservative approach with an adaptive control strategy that optimizes both emissions and fuel consumption.
Solution Approach 2:
The control method changes the operational parameters of the EGR system by switching between different circuits (high-pressure vs. low-pressure) based on catalyst efficiency. This parameter change allows the system to exploit the benefits of low-pressure EGR (lower fuel consumption) when conditions permit and switch to high-pressure EGR (better combustion stability) when needed.
3Reliability
If conservative EGR control is used without considering catalyst efficiency, then incomplete combustion is prevented, but fuel consumption increases unnecessarily
Solution Approach 1:
The invention introduces feedback from catalyst efficiency monitoring to the EGR control decision-making process. The control unit receives information about catalyst performance and uses this feedback to adjust the EGR strategy, eliminating the need for overly conservative control when the catalyst is functioning efficiently.
Solution Approach 2:
The system uses the catalyst's own performance characteristics to guide the EGR control strategy. By monitoring the catalyst's efficiency and using this information to adjust EGR circuit selection, the system allows the catalyst to effectively regulate its own operational conditions, optimizing overall system performance.
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 optimizes emissions reduction by aligning EGR circuit usage with catalyst efficiency, reducing fuel consumption and minimizing risks of incomplete combustion, while maintaining compliance with emission regulations.
Implementation Method 1
an oxidation catalyst 3 which makes it possible to reduce the molecules of unburnt hydrocarbons (HC) and carbon monoxide (CO)
Data Source
Figure 1
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Figure 5~6
AI summary
The invention relates to a method for treating exhaust gases of a supercharged internal combustion engine (1) of a motor vehicle, said gases being partially recirculated at high pressure and low pressure to the intake, said method including: a step of recirculating a HP EGR gas flow (QEGR HP) to the engine (1); and a step of recirculating a LP EGR gas flow (QEGR BP) to the engine (1), characterised in that the proportion (a) of LP EGR gas is determined according to the actual efficiency (ε) of the treatment device (3).