Internal Combustion Engine Catalytic Converter Purging
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Solution Overview
Problem
Existing methods for operating internal combustion engines with catalytic converters face challenges in efficiently purging stored oxygen during coasting phases without causing excessive wear and emissions, particularly due to the need for mixture enrichment which can lead to increased CO, HC, and particle emissions.
Innovation Solution
The method involves selecting a purging combustion chamber to expel non-combusted fuel into the catalytic converter at the beginning of a load operation phase, ensuring the catalytic converter is brought back to the optimal operating window without intense mixture enrichment, thereby reducing wear and emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If intense mixture enrichment is used to purge the catalytic converter, then the catalytic converter can be brought back to the catalytic converter window, but the internal combustion engine suffers from increased wear and tear and higher emissions
Solution Approach 1:
The invention divides the purging function between two different combustion chambers: the first combustion chamber performs normal combustion, while a second combustion chamber is dedicated to generating non-combusted fuel for purging the catalytic converter. This segmentation allows the purging function to be separated from normal combustion, enabling effective oxygen removal without requiring intense mixture enrichment in all chambers, thereby reducing emissions and engine wear.
2Productivity
If non-combusted fuel is expelled into the catalytic converter, then oxygen can be removed effectively, but the fuel must be delivered at precise timing to ensure it does not combust in the combustion chamber
Solution Approach 1:
The invention applies preliminary action by injecting fuel into the second combustion chamber before the exhaust stroke begins, during a period when the chamber pressure and temperature conditions favor fuel expulsion rather than combustion. This timing ensures the fuel is delivered into the exhaust stream and transported to the catalytic converter before combustion can occur, achieving effective purging without requiring complex real-time combustion control.
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 reduces engine wear and minimizes exhaust emissions by effectively purging the catalytic converter without the need for rich mixture enrichment, thereby maintaining converter efficiency and reducing NOx emissions.
Implementation Method 1
feeding a first fuel quantity into the purging combustion chamber such that the first fuel quantity, prior to igniting the fuel in the purging combustion chamber, is expelled so as to be at least partially—preferably fully—non-combusted in the direction of the exhaust-gas catalytic converter
Data Source
AI summary
Operating an internal combustion engine (110) having at least two combustion chambers (1-6) and at least one exhaust-gas catalytic converter (130). In one example, a beginning of the load operation phase of the internal combustion engine (110) that adjoins a coasting phase is detected. A combustion chamber of the at least two combustion chambers (1-6) is determined as the first combustion chamber; and one of other the combustion chambers is selected as the purging combustion chamber. An exhaust gas of the purging combustion chamber is directed into the same exhaust-gas catalytic converter (130) as an exhaust gas of the first combustion chamber. A first fuel quantity is fed into the purging combustion chamber such that the first fuel quantity, prior to igniting the fuel in the purging combustion chamber, is discharged to be partially or fully non-combusted in the direction of the exhaust-gas catalytic convertor (130).