Preheating Lambda Probe for Cold Start Emission Control
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Solution Overview
Problem
Existing methods for starting internal combustion engines fail to ensure minimal exhaust emissions immediately after startup due to undefined temperature levels of lambda probes, leading to increased untreated emissions and reduced catalytic converter effectiveness.
Innovation Solution
A method involving an electrically heatable lambda probe and catalytic converter with an oxygen accumulator, where the lambda probe is preheated before engine startup, allowing for precise lambda-controlled lean operation, followed by stoichiometric and oscillating lambda control as the catalytic converter reaches operational temperatures, optimizing exhaust gas conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lambda probe is not preheated before engine startup, then the engine can be started immediately, but the exhaust emissions increase and catalytic converter effectiveness is reduced
Solution Approach 1:
The lambda probe is preheated to its operating temperature before the engine is started. This preliminary action ensures that the lambda probe is ready for immediate lambda control upon engine startup, enabling precise fuel/air mixture regulation from the beginning and preventing increased exhaust emissions that would occur with an undefined temperature probe
2Productivity
If pre-control of lambda value is used without preheating the lambda probe, then the engine can operate immediately, but the actual lambda value deviates from target value by one to two percent
Solution Approach 1:
The lambda probe is preheated before engine startup to ensure it reaches its operating temperature in advance. This preliminary heating action eliminates measurement inaccuracies that would otherwise occur during the first seconds of engine operation, ensuring the actual lambda value matches the target value precisely from startup
3Device complexity
If the lambda probe temperature is not controlled before startup, then the system is simpler, but untreated emissions increase and catalytic converter heating effectiveness is reduced
Solution Approach 1:
The lambda probe is preheated before engine startup through a controlled heating process. This preliminary action, though it adds some system complexity, significantly reduces untreated emissions by ensuring accurate lambda control from the moment the engine starts, and improves catalytic converter heating effectiveness by providing precise feedback from the beginning
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
Significantly reduces harmful HC, CO, and NOx emissions directly after startup and achieves rapid conversion rates at the catalytic converter, ensuring improved exhaust gas quality and efficiency.
Implementation Method 1
the lambda probe is electrically heated during a first phase before the internal combustion engine is started
Implementation Method 2
catalytic converters show the best efficiency in the so-called lambda window with a λ between 0.97 and 1.03, i.e. the best cleaning performance through efficient exhaust gas conversion
Implementation Method 3
the catalytic converter having an oxygen accumulator (Oxygen Storage Capacity OSC)
Data Source
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AI summary
The invention relates to a method for commissioning an internal combustion engine (10), the exhaust gas system (20) of which is equipped with an electrically heatable lambda sensor (24) and a catalytic converter (30) with an oxygen reservoir (50). The combination of method steps according to the invention allows the internal combustion engine (10) to be started with an optimal raw emission reduction directly after the cold start and an optimal pollutant conversion in the warm-up phase. The invention likewise relates to a motor vehicle comprising an internal combustion engine (10) and an exhaust gas system (20) connected thereto, having an electrically heatable lambda sensor (24) and a catalytic converter (30) with an oxygen reservoir (50), and to a controller (42), wherein the controller (42) is designed to carry out the method according to the invention.