bei Google ScholarTitelangaben
Moos, Ralf ; Walter, Stefanie ; Steiner, Carsten ; Hagen, Gunter:
Sensing catalytic converters and filters at work using radio frequencies.
2018
Veranstaltung: Eurosensors XXXII
, September 9 - 12, 2018
, Graz, Austria.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung
,
Vortrag
)
Abstract
The state of catalysts and filters plays a key role in automotive exhaust gas aftertreatment. The soot or ash loading of particulate filters (Gasoline or Diesel Particulate Filters; GPF or DPF), the oxygen loading degree of three-way catalysts (TWC), the amount of stored ammonia in SCR catalysts, or the NOx loading degree in lean NOx traps (LNT; a.k.a. NOx storage catalysts, NSC) are important parameters. Today, they are determined indirectly and/or based on models that are calibrated by gas sensors installed up- or downstream of the catalysts or by differential pressure sensors in the case of filters. In other words, state determination is standard for all exhaust gas aftertreatment devices. This contribution overviews a novel approach to determine directly the state of the devices by a radio frequency based technique, in the following denoted as “rf technique”. For that purpose, the housing of the device serves as a cavity resonator. As “sensing” element, one or two simple antennas, are mounted in the catalyst canning. The electrical properties of the device (ceramic honeycomb incl. coating and storage material) can be measured. Such contactless-obtained information is very well correlated with the catalyst or filter state as will be demonstrated for different exhaust gas aftertreatment systems.