Radio-Frequency-Controlled Urea Dosing for NH3-SCR Catalysts: NH3 Storage Influence to Catalyst Performance under Transient Conditions

Sensors

Gunter Hagen¹  Markus Dietrich¹  Ralf Moos¹  Katharina Burger²  Willibald Reitmeier²  Markus Hien²  Philippe Grass²  Jaco Visser³  David Kubinski³ 

[1] Bayreuth Engine Research Center (BERC), Department of Functional Materials, University of Bayreuth, 95447 Bayreuth, Germany;Continental Automotive GmbH, Division Powertrain, 93055 Regensburg, Germany;Ford Research and Innovation Center, Dearborn, MI 48124, USA;

关键词: radio-frequency (RF);    NH3 SCR;    NH3 storage;    NOx conversion;    NH3 slip;    direct control;    microwave cavity perturbation;    transient conditions;    storage influence;   

DOI  :  10.3390/s17122746

来源: DOAJ

【 摘 要 】

Current developments in exhaust gas aftertreatment led to a huge mistrust in diesel driven passenger cars due to their NOx emissions being too high. The selective catalytic reduction (SCR) with ammonia (NH3) as reducing agent is the only approach today with the capability to meet upcoming emission limits. Therefore, the radio-frequency-based (RF) catalyst state determination to monitor the NH3 loading on SCR catalysts has a huge potential in emission reduction. Recent work on this topic proved the basic capability of this technique under realistic conditions on an engine test bench. In these studies, an RF system calibration for the serial type SCR catalyst Cu-SSZ-13 was developed and different approaches for a temperature dependent NH3 storage were determined. This paper continues this work and uses a fully calibrated RF-SCR system under transient conditions to compare different directly measured and controlled NH3 storage levels, and NH3 target curves. It could be clearly demonstrated that the right NH3 target curve, together with a direct control on the desired level by the RF system, is able to operate the SCR system with the maximum possible NOx conversion efficiency and without NH3 slip.

【 授权许可】

Unknown