Exhaust Filter Regeneration via Aldehyde Mediation
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Solution Overview
Problem
Current particle filter regeneration methods in internal combustion engines face challenges such as increased exhaust-gas backpressure, limited NO2 formation at high temperatures, and the risk of thermal damage due to excessive temperature increases during active regeneration, leading to inefficient soot oxidation and high carbon monoxide emissions.
Innovation Solution
A device and method that combines passive and active regeneration by using a heating device to increase exhaust-gas temperature upstream of the particle filter, maintaining high NO2 availability and reducing hydrocarbon concentrations, allowing for controlled temperature adjustments to optimize soot oxidation using NO2 as the primary oxidizing agent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If active regeneration is used to increase exhaust-gas temperature for soot oxidation, then soot oxidation efficiency is improved, but thermal damage risk and fuel consumption increase
Solution Approach 1:
The patent changes the chemical composition parameter by introducing a hydrocarbon-containing agent that reacts to form aldehydes, which then serve as intermediaries for soot oxidation. This alternative chemical pathway enables effective soot oxidation without requiring excessive temperature increases, thereby resolving the contradiction between oxidation efficiency and thermal damage risk
Solution Approach 2:
The patent introduces aldehydes as intermediary substances that mediate between the hydrocarbon-containing agent and soot particles. These aldehydes act as mild oxidizing agents that can effectively oxidize soot at lower temperatures, thus improving soot oxidation efficiency while avoiding the thermal damage associated with high-temperature active regeneration
2Productivity
If NO oxidation catalytic converter is used to form NO2 for passive regeneration, then soot oxidation is improved, but NO2 formation is limited at high temperatures
Solution Approach 1:
The patent introduces aldehydes as intermediary oxidizing agents that can effectively oxidize soot particles across a broader temperature range than NO2 alone. These aldehydes complement the NO2 oxidation mechanism, ensuring continuous effective soot oxidation even when NO2 formation is thermodynamically limited at elevated temperatures
Solution Approach 2:
The patent changes the oxidizing agent composition by adding hydrocarbon-derived aldehydes to the exhaust gas mixture. This compositional change provides an alternative oxidation pathway that is less temperature-sensitive than NO2-based oxidation, thereby maintaining soot oxidation effectiveness across varying temperature conditions
3Reliability
If heating device is used to control exhaust-gas temperature, then regeneration control is improved, but device complexity increases
Solution Approach 1:
The patent employs a self-service approach where the hydrocarbon-containing agent automatically reacts with oxygen in the exhaust gas to form aldehydes and heat. This self-heating mechanism provides temperature control for regeneration without requiring external heating devices, thereby improving regeneration reliability while avoiding increased system complexity
Solution Approach 2:
The patent uses aldehydes as intermediary substances that facilitate controlled soot oxidation at moderate temperatures. This chemical mediation allows effective regeneration without the need for complex thermal management systems, as the aldehyde oxidation process naturally occurs within a favorable temperature window
4Object-generated harmful factors
If particle filter is used instead of particle separator, then fine matter particle removal is improved, but exhaust-gas backpressure increases
Solution Approach 1:
The patent converts the accumulated soot particles, which normally represent a harmful blockage increasing backpressure, into a beneficial fuel source. By dosing hydrocarbon-containing agent that forms aldehydes, the system enables in-situ oxidation of the stored soot, transforming the harmful accumulation into an active regeneration process that clears the filter and reduces backpressure
Solution Approach 2:
The patent introduces aldehydes as intermediary oxidizing agents that enable effective soot oxidation within the particle filter structure. These aldehydes can penetrate and oxidize soot particles throughout the filter medium, effectively removing fine matter particles while maintaining more favorable pressure characteristics compared to conventional high-temperature burn-off methods
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 reliable, efficient, and safe particle filter regeneration with reduced fuel consumption, lower thermal loading, and minimized carbon monoxide emissions, while avoiding uncontrollable temperature increases and extending the intervals between active temperature increases.
Implementation Method 1
upstream of the particle filter, there is also provided at least one heating device by means of which an exhaust-gas flow conducted to the particle filter can be heated
Implementation Method 2
an oxidation catalytic converter for the oxidation of NO, to form NO2 in particular, arranged upstream of the particle filter
Implementation Method 3
The NO2 is in turn converted in the particle filter with the hydrocarbon-containing superfine particles to form CO, CO2, N2 and NO
Data Source
AI summary
A device and a method for regenerating a particulate filter that is arranged in the exhaust tract of an internal combustion engine. There is disposed at least one NO oxidation catalytic converter upstream of the particulate filter for the oxidation of NO, and in particular to form NO2. At least one heating device is also provided upstream of the particulate filter, by way of which an exhaust-gas flow that is conducted towards the particulate filter can be heated to a defined temperature in accordance with defined regeneration parameters, in particular in accordance with a degree of loading of the particulate filter and/or in accordance with an efficiency of an NO2-based regeneration of the particulate filter by way of an NO2 quantity formed in the at least one NO oxidation catalytic converter.