Microwave-Based Oxidation State and Soot Loading Determination on Gasoline Particulate Filters with Three-Way Catalyst Coating for Homogenously Operated Gasoline Engines

Sensors

Markus Dietrich¹  Christoph Jahn¹  Peter Lanzerath²  Ralf Moos¹ 

[1] Department of Functional Materials, Bayreuth Engine Research Center (BERC), Zentrum für Energietechnik (ZET), University of Bayreuth, 95440 Bayreuth, Germany; E-Mails:;Daimler AG, 70546 Stuttgart, Germany; E-Mail:

关键词: gasoline particulate filter (GPF);    three-way catalytic converter (TWC);    oxygen storage capacity (OSC);    on-board diagnostics (OBD);    microwave cavity perturbation method;    New European Driving Cycle (NEDC);    lambda probe;   

DOI  :  10.3390/s150921971

来源: mdpi

【 摘 要 】

Recently, a novel method emerged to determine the oxygen storage degree of three way catalysts (TWC) by a microwave-based method. Up to now, this method has been investigated only in lab-scale reactors or under steady state conditions. This work expands those initial studies. A TWC-coated gasoline particulate filter was investigated in a dynamic engine test bench simulating a typical European driving cycle (NEDC). It could be shown that both the oxygen storage degree and the soot loading can be monitored directly, but not simultaneously due to their competitive effects. Under normal driving conditions, no soot accumulation was observed, related to the low raw emissions and the catalytic coating of the filter. For the first time, the quality factor of the cavity resonator in addition to the resonance frequency was used, with the benefit of less cross sensitivity to inconstant temperature and water. Therefore, a temperature dependent calibration of the microwave signal was created and applied to monitor the oxidation state in transient driving cycles. The microwave measurement mirrors the oxidation state determined by lambda probes and can be highly beneficial in start-stop phases (where lambda-probes do not work) and to determine the oxygen storage capacity (OSC) without unnecessary emissions.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.