The Behavior of Metal DPFs at Low Temperatures in Conjunction with a Cerium Based Additive

A light duty truck Renault Trafic with a naturally aspirated 2.5 l diesel engine was equipped with metal particulate filters of different sizes, installed at different positions along the exhaust pipe of the vehicle. The filters were operated on diesel fuel doped with a cerium based additive at concentration of 100 ppm in the fuel. Tests were carried out on chassis dynamometer using continuous repetition of the urban part of the European Driving Cycle as a « worst case » approach. Comparisons are made between the different sizes and positioning as regards both back-pressure build up and catalytic regeneration behavior. The results show that filter regeneration was always possible at continuous low speed driving, at relatively high filter back-pressure levels (i.e. high particulate accumulation in the filter), with an effect on fuel consumption. As expected, the New European Driving Cycle, with alternate urban and extra urban operation of the vehicle, always provides the necessary conditions for trap regeneration therefore affects neither the fuel consumption nor maximum engine power output. The paper investigates a number of engineering parameters related to the design and the installation of such a system with fully passive operation on a light duty truck.