Details

Autor(en) / Beteiligte

• Jiang, Yu
• Yang, Jiacheng
• Cocker, David
• Karavalakis, Georgios
• Johnson, Kent C.
• Durbin, Thomas D.

Titel

Characterizing emission rates of regulated pollutants from model year 2012+ heavy-duty diesel vehicles equipped with DPF and SCR systems

Ist Teil von

• The Science of the total environment, 2018-04, Vol.619-620, p.765-771

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •NOx emissions varied depending on the test cycle and the test truck.•The lowest NOx emissions were found for highway driving conditions.•NOx emissions under urban driving conditions ranged from 0.495 to 1.363g/mi.•The highest NOx emissions were found for stop-and-go creep type of driving.•PM, THC, and CO emissions were very low for most of the vehicles and conditions. Fig. Comparisons of NOx emission rates from this study, ARB and SCAQMD studies for SCR-equipped 2010+ vehicles over the UDDS; D1* represents the UDDS emissions level found after retesting the manufacturer D1 truck after a regeneration; A2** and B** represents results from ARB retest. [Display omitted] The regulated emissions of five 2012 and newer, low-mileage, heavy-duty Class 8 diesel trucks equipped with diesel particulate filters (DPFs) and selective catalytic reduction (SCR) systems were evaluated over test cycles representing urban, highway, and stop-and-go driving on a chassis dynamometer. NOx emissions over the Urban Dynamometer Driving Schedule (UDDS) ranged from 0.495 to 1.363g/mi (0.136 to 0.387g/bhp-hr) for four of the normal emitting trucks. For those trucks, NOx emissions were lowest over the cruise (0.068 to 0.471g/mi) and high-speed cruise (0.067 to 0.249g/mi) cycles, and highest for the creep cycle (2.131 to 9.468g/mi). A fifth truck showed an anomaly in that it had never regenerated throughout its relatively short operating lifetime due to its unusual, unladed service history. This truck exhibited NOx emissions of 3.519g/mi initially over the UDDS, with UDDS NOx emissions decreasing to 0.39g/mi after a series of parked regenerations. PM, THC, and CO emissions were found to be very low for most of the testing conditions, due to the presence of the DPF/SCR aftertreatment system, and were comparable to background levels in some cases.