An Experimental Study of Active Regeneration of an Advanced Catalyzed Particulate Filter by Diesel Fuel Injection Upstream of an Oxidation Catalyst

Abstract

Passive regeneration (oxidation of particulate matter without using an external energy source) of particulate filters in combination with active regeneration is necessary for low-load engine operating conditions. For low-load conditions, the exhaust gas temperatures are less than 250\mDC and the PM oxidation rate due to passive regeneration is less than the PM accumulation rate. The objective of this research was to experimentally investigate active regeneration of a catalyzed particulate filter (CPF) using diesel fuel injection in the exhaust gas after the turbocharger and before a diesel oxidation catalyst (DOC) and to collect data for extending the MTU 1-D, 2-layer model to include the simulation of active regeneration. The engine used in this study was a 2002 Cummins ISM turbocharged 10.8 L heavy-duty diesel engine with cooled EGR. The exhaust after-treatment system consisted of a Johnson Matthey DOC and CPF (a CCRT\sR). Steady-state loading experiments at 20% load at rated speed were performed for different times in order to achieve three particulate matter loadings of 1.1, 2.2 and 4.1 grams of particulate/liter of filter. Active regeneration was carried out at three CPF-inlet temperatures of 500, 550 and 600\mDC to cover a range of temperatures and filter loadings for thermal regeneration. The dependent data of fuel usage, time of regeneration, mass of PM oxidized and maximum substrate temperature are presented as a function of mass loading and inlet CPF temperature. The results show that higher CPF-inlet temperature and particulate matter mass loading are more effective for regeneration of the CPF and lower fuel usage in grams of PM oxidized per gallon of fuel used whereas low temperatures and lower mass loadings were not as effective due to lower reaction rates. 90% of the HC from the diesel fuel injection were oxidized across the DOC while the other 10% were oxidized across the CPF under the test conditions.

Low Power Autoselective Regeneration of Monolithic Wall Flow Diesel Particulate Filters

“…However, these systems usually require expensive catalyst materials such as platinum. Upstream oxidation catalysts have also been used with fuel sprays to increase the exhaust gas temperature [14] . Problems achieving reliable regeneration temperatures are often encountered with the low exhaust gas temperature of modern diesel engines.…”

Numerical investigation on the energetic performances of conventional and pellet aftertreatment systems in flow-through and reverse-flow designs

“…The composition of the exhaust gas was calculated from the combustion of C 12 H 24 with excess air, in accordance with the literature [26]. An equivalent mass flow rate of methane, that is representative of the combined exhaust HC and CO in average Diesel, has been assumed in order to calculate the oxidation of the unburned HC that are present in the exhaust gas [14].…”

A Comparative Energetic Analysis of Active and Passive Emission Control Systems Adopting Standard Emission Test Cycles

“…In accordance with the literature [9], the composition of the exhaust gas was calculated from the combustion of C 12 H 24 with excess air. Referring to the control volume, the thermal exchange can be described as follows:…”