Lightoff Fluid Injection for DOC Desulfation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The catalytic surfaces of diesel oxidation catalysts (DOC) become contaminated with sulfur compounds, reducing their effectiveness, and existing methods to regenerate them, such as increasing exhaust temperatures, incur efficiency penalties and additional costs.
Innovation Solution
Introducing a lightoff fluid with a lower ignition temperature than the compression ignition fuel into the exhaust stream upstream of the DOC, where it ignites and raises the temperature to desulfate the catalyst and ignite the fuel, thereby regenerating the DOC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engine thermal management is used to increase exhaust temperatures to regenerate the DOC, then the catalyst effectiveness is improved, but efficiency penalties and increased equipment costs occur
Solution Approach 1:
A lightoff fluid with lower ignition temperature is introduced as an intermediary substance to initiate combustion. This lightoff fluid acts as a mediator that enables the compression ignition fuel to ignite at lower exhaust temperatures, thereby regenerating the DOC without requiring significant increases in exhaust temperature that would cause efficiency penalties
Solution Approach 2:
The ignition temperature parameter of the fuel mixture is changed by introducing a lightoff fluid with inherently lower ignition temperature. This parameter change allows the combustion process to occur at lower temperatures than would be required for pure compression ignition fuel, enabling DOC regeneration while avoiding efficiency losses
2Reliability
If engine thermal management is used to increase exhaust temperatures to regenerate the DOC, then the catalyst effectiveness is improved, but additional equipment costs are incurred
Solution Approach 1:
The lightoff fluid serves as a chemical intermediary that enables DOC regeneration through a simpler approach. Instead of requiring complex thermal management systems to raise exhaust temperatures, the lightoff fluid chemically facilitates ignition at existing temperatures, reducing equipment complexity and cost
Solution Approach 2:
The lightoff fluid enables the exhaust system to self-regenerate the DOC without requiring external thermal management intervention. The chemical properties of the lightoff fluid itself provide the mechanism for ignition and regeneration, eliminating the need for additional heating equipment or complex control systems
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 method effectively desulfates the DOC, regenerates it, and increases its performance without the need for additional temperature-raising mechanisms, thus improving the efficiency of the exhaust system.
Implementation Method 1
a lightoff fluid delivery device configured to deliver the lightoff fluid into the upstream exhaust conduit to light off the compression ignition fuel
Implementation Method 2
an oxidation catalyst (DOC) arranged fluidly between the upstream exhaust conduit and the downstream exhaust conduit
Data Source
AI summary
A compression ignition internal combustion engine system includes an engine and an exhaust system with an upstream exhaust conduit, and an oxidation catalyst device (DOC). Systems and methods of desulfating the oxidation catalyst by the injection of a lightoff fluid to promote ignition of uncombusted fuel in the exhaust stream are disclosed.