Recent Advances in Utilizing the Plasma Fuel Reformer for NOx Trap Regeneration 2005-01-3547
This paper describes recent progress in our program to develop an emissions technology allowing diesel engines to meet the upcoming stringent worldwide regulations for NOx. The Plasma Fuel Reformer (PFR) has the ability to rapidly convert diesel fuel (with air), to a hydrogen rich gas on-board a vehicle, which is then utilized to efficiently regenerate a NOx trap. We have made several advances on the PFR as well as on the NOx reducing system. The Plasma Fuel Reformer operating range has been extended by 120% up to 1.5 g/s fuel flow rate while retaining the high hydrogen and low soot characteristics. The plasma power consumption has been further reduced and the high voltage design has been made more robust. The T90 start-up time during regenerations has been reduced to less than 4 seconds. The NOx reducing system utilizes a novel algorithm for NOx trap regeneration that reduces the fuel penalty by 25% while increasing NOx conversion by 10%. The new method can also be utilized to reduce the NOx trap volume significantly in a dual leg arrangement. Based on a detailed understanding of the NOx trap regeneration process, a new method to reduce the magnitude of NOx spikes has also been developed. Finally, optimization was performed at some steady state points utilizing maps on trap capacity and reductant breakthrough.
Particulates-Emission Control; NOx Emission Control; Integrated Emissions Systems; Emissions Measurements; and Worldwide On-Road Emission Control Experience Europe, USA and Japan-SP-1986, SAE 2005 Transactions Journal of Commercial Vehicles-V114-2