Control Strategy for Urea-SCR System in Single Step Load Transition Waseda University

Format:

Conference/Event

Author/Creator:

Nakayama, Ryota, author.

Conference Name:

Powertrain & Fluid Systems Conference and Exhibition (2006-10-16 : Toronto, Canada)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2006

Summary:

Urea-SCR system has a high NOx reduction potential in the steady-state diesel engine operation. In complicated transient operations, however, there are certain problems with the urea-SCR system in that NOx reduction performance degrades and adsorbed NH3 would be emitted.Here, optimum urea injection methods and exhaust bypass control to overcome these problems are studied. This exhaust bypass control enables NO/NOx ratio at the inlet of SCR catalyst to be decreased widely, which prevents over production of NO2 at the pre-oxidation catalyst.Steady-state and simple transient engine tests were conducted to clarify NOx reduction characteristics when optimum urea injection pattern and exhaust bypass control were applied. In simple transient test, only the engine load was rapidly changed for obtaining the fundamental knowledge concerning the effect of those techniques.Transient test results shows that cutting urea injection and supplying the exact required amount of urea calculated from inlet NOx concentration reduce NH3 slip and NOx as much as possible. In addition, exhaust bypass control also reduced NOx more quickly for the period when NO2 was excessively formed at pre-DOC

Notes:

Vendor supplied data

Publisher Number:

2006-01-3308

Access Restriction:

Restricted for use by site license