Exhaust Combustor Heating SCR Converter with Soot Filter
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Solution Overview
Problem
Existing exhaust systems for internal combustion engines face challenges in achieving low-emission operations, particularly in heating the SCR catalytic converter efficiently while minimizing particulate filter heating and avoiding excessive particle emissions.
Innovation Solution
Incorporating a combustor upstream of the SCR catalytic converter and downstream of the particulate filter to heat the exhaust gas, combined with a separate filter element to capture soot particles from the combustor exhaust gas, allowing for efficient heating of the SCR catalytic converter without excessive particulate filter heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a combustor is used to heat the SCR catalytic converter, then the heating capacity is improved, but particle emissions increase
Solution Approach 1:
The exhaust system is segmented into distinct functional zones: a first section for particulate filtration (downstream of the combustor), and a second section for SCR denitrification (upstream of the combustor). This spatial segmentation allows the combustor to heat the SCR zone without compromising the particulate filter's ability to capture particles from the engine exhaust, as each zone is optimized for its specific function with appropriate positioning of the combustor between them.
Solution Approach 2:
The exhaust gas flow acts as an intermediary medium that carries heat from the combustor to the SCR catalytic converter while passing through the particulate filter. The controlled exhaust gas flow rate and temperature distribution ensure that heat is transferred effectively to the SCR zone without causing excessive particle emissions, as the filter captures particles before they can be re-emitted by the combustor heat.
2Temperature
If the particulate filter is heated excessively, then the SCR catalytic converter heating is improved, but the filter performance deteriorates
Solution Approach 1:
The exhaust system is divided into distinct thermal zones: the combustor is positioned to heat the SCR catalytic converter directly, while the particulate filter is located in a cooler zone downstream of the combustor. This segmentation ensures that the filter operates at temperatures suitable for maintaining its catalytic activity and particle capture efficiency, while the SCR zone receives the necessary heat for denitrification.
Solution Approach 2:
Different local thermal conditions are created in different sections of the exhaust system. The SCR catalytic converter is located in a high-temperature zone for effective denitrification, while the particulate filter is positioned in a moderate-temperature zone that preserves its filtering performance. The combustor is strategically placed to provide localized heating only where needed (at the SCR zone) without excessively heating the filter area.
3Object-generated harmful factors
If a separate filter element is added for the combustor exhaust, then particle emissions are reduced, but device complexity increases
Solution Approach 1:
The exhaust system is segmented into functional modules: the combustor for heating, the first particulate filter for capturing engine exhaust particles, the SCR catalytic converter for denitrification, and the second particulate filter for capturing combustor exhaust particles. This modular segmentation allows each component to be optimized independently and facilitates easier maintenance and replacement of individual elements without affecting the entire system.
Solution Approach 2:
The second particulate filter is extracted specifically for the function of capturing particles from the combustor exhaust gas, separating this function from the first filter that handles engine exhaust particles. This extraction allows the system to address the specific particle emission problem of the combustor without redesigning the entire exhaust system, thereby limiting the increase in device complexity to only the necessary additional component.
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 cold-start emissions, nitrogen oxide emissions, and carbon dioxide emissions, while providing a high heating capacity independent of the vehicle's electrical system, and prevents deposits in the hydrolysis section, thereby ensuring efficient exhaust gas purification.
Implementation Method 1
the combustor can provide the combustor exhaust gas by combusting a fuel-air mixture
Implementation Method 2
the exhaust gas from the combustor can mix with the engine exhaust gas, thereby heating the engine exhaust gas
Implementation Method 3
the exhaust system has, in particular at least or exactly, one filter element, in particular provided in addition to the particulate filter and spaced apart from the particulate filter, for filtering out particles, in particular soot particles, from the exhaust gas of the combustor
Implementation Method 4
The SCR catalytic converter is catalytically effective for selective catalytic reduction (SCR). This means that the SCR catalytic converter is designed to catalytically effect and/or support the selective catalytic reduction (SCR)
Implementation Method 5
In the course of the selective catalytic reduction that takes place in the SCR catalytic converter, for example, nitrogen oxides (NOx) contained in the exhaust gas are converted to water (H2O) and nitrogen (N2)
Data Source
AI summary
An exhaust system of an internal combustion engine of a motor vehicle includes a particulate filter where particles are filterable out from the exhaust gas by the particulate filter. A selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine is flowable for denitrifying the exhaust gas from the internal combustion engine is disposed downstream of the particulate filter. The exhaust gas of the internal combustion engine is heatable by a combustor at a point disposed upstream of the SCR catalytic converter and downstream of the particulate filter where the combustor provides an exhaust gas of the combustor. Particles are filterable out from the exhaust gas of the combustor by a filter element.