Local Temperature Measurement for Catalytic Converter Conversion
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Solution Overview
Problem
Conventional methods for determining the conversion capability of exhaust gas catalytic converters rely on average temperatures, which do not accurately reflect the gradual heating process and varying conditions within the catalytic converter, leading to inefficient heating measures and potential emissions issues.
Innovation Solution
A method that assesses local conversion capabilities at multiple locations within the catalytic converter based on temperature, weighting these capabilities to determine a global conversion capability, considering factors like aging, geometry, and catalytic active material distribution, allowing for precise adaptation of heating measures and engine control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If average temperature is used to determine conversion capability, then measurement complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The catalytic converter is divided into multiple spatial zones (e.g., axial segments and radial layers) with temperature sensors placed at each zone. This segmentation allows independent temperature measurement at different locations, capturing the gradual heating process from inlet to outlet and from center to periphery, thereby improving conversion capability assessment without requiring an overly complex single-point measurement system
Solution Approach 2:
The invention transitions from one-dimensional average temperature measurement to three-dimensional spatial temperature distribution measurement. By adding spatial dimensions (axial position and radial position) to the temperature measurement, the system captures the gradient nature of heating in the catalytic converter, significantly improving measurement precision while maintaining manageable system complexity through systematic sensor placement
2Measurement precision
If local temperature measurement at multiple locations is implemented, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The catalytic converter is divided into multiple spatial zones (e.g., axial segments and radial layers) with temperature sensors placed at each zone. This segmentation allows independent temperature measurement at different locations, capturing the gradual heating process from inlet to outlet and from center to periphery, thereby improving conversion capability assessment without requiring an overly complex single-point measurement system
Solution Approach 2:
The distributed temperature measurement system serves multiple functions: it monitors conversion capability, detects thermal gradients, identifies cold spots, and provides data for control strategies. This multi-functionality justifies the increased device complexity by delivering comprehensive diagnostic and control information from a single measurement infrastructure
3Reliability
If catalytic converter heating measures are applied, then conversion capability is improved, but energy consumption increases
Solution Approach 1:
The system applies heating measures in advance during the cold start phase before the catalytic converter reaches operating temperature. By detecting low temperatures at multiple locations and activating heating strategies (such as rich mixture injection or secondary air injection) during this preliminary phase, the system ensures rapid light-off while minimizing prolonged energy consumption once target temperature is achieved
Solution Approach 2:
The distributed temperature measurement system provides real-time feedback on the thermal state of different zones within the catalytic converter. This feedback enables dynamic adjustment of heating measures - intensifying heating in cold zones and reducing it in warm zones - thereby optimizing energy consumption while ensuring uniform heating and reliable conversion capability across the entire converter
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 enables more precise control of catalytic converter heating and engine operation, improving efficiency and reducing emissions by targeting specific areas for heating and adjusting engine parameters based on localized conversion capabilities, ensuring effective conversion of harmful substances.
Implementation Method 1
an example embodiment provides for determining a conversion capability of one or multiple catalytic converters (11, 12, 13) downstream from an internal combustion engine (1). For this purpose, a respective local temperature (T) is ascertained at multiple locations (11.1, 11.2, 11.3, 12.1, 12.2, 12.3, 13.1, 13.2, 13.3) or partial volumes within the one or the multiple catalytic converters (11, 12, 13)
Implementation Method 2
Catalytic converters are used in exhaust gas systems of gasoline and diesel engines for converting the gaseous harmful substances (e.g., hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx)). These catalytic converters ensure an almost complete conversion of these harmful substances in the warmed-up operating state. Chemical reactions take place in the catalytic converter in the process.
Implementation Method 3
For example, HC and CO are oxidized to CO2 and water.
Implementation Method 4
NOx is reduced to N2.
Implementation Method 5
In this process, e.g., the efficiency of the gasoline engine is worsened by late ignition angles, and the exhaust gas temperature and the enthalpy input into the catalytic converter are thus increased.
Data Source
AI summary
A method for determining a conversion capability of one or multiple exhaust gas catalytic converters, downstream from an internal combustion engine. The method includes ascertaining a respective local temperature at multiple locations within the one or the multiple catalytic converters, ascertaining a local conversion capability for a section or a partial volume of the one or the multiple catalytic converters based on the local temperature, and ascertaining a global conversion capability of the one or the multiple catalytic converters based on the ascertained local conversion capabilities. A processing unit and a computer program product for carrying out such a method are also described.