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Experimental and theoretical methods are presented to characterize the transient filtration efficiency (FE) behavior of Diesel Particulate Filters (DPFs) exposed to soot laden exhaust gas streams under laboratory and engine exhaust conditions. A (1+1) dimensional transient model, comprising a one dimensional channel model in combination with a one dimensional wall microstructure model is presented to study the sensitivity of the FE behavior on DPF microstructure and geometry properties, along with the impact of the hydrodynamic and aerosol flow conditions (flow rate, temperature, aerosol characteristics). The dynamic model also considers the dynamic soot oxidation by passive regeneration. The model has been validated through use of an extensive set of experimental data obtained under different operating conditions and with DPFs of different microstructure.

With the introduction of EU6d and CN6 all vehicles with gasoline direct injection and many with port fuel injection engine will be equipped with a gasoline particulate filter (GPF). A range of first generation filter technologies has been introduced successfully, helping to significantly reduce the tailpipe particulate number emissions. The continued focus on particulate emissions and the increasing understanding of their impact on human health, combined with the advanced emission regulations under RDE conditions results in the desire for filters with even higher filtration efficiency, especially in the totally fresh state. At the same time, to balance with the requirements on power and CO2, limitations exist with respect to the tolerable pressure drop of filters. In this paper we will report on a new generation of gasoline particulate filters for uncatalyzed applications.

As the official proposal for emission regulation Euro 7 has been released by European Commission, PN above 10nm is taken into consideration for the ultrafine particulate emissions control. The challenges of GPF filtration efficiency emerge for the light-duty manufactures to meet the future emission standards. In the present study, a China 6 compliant vehicle was tested to reveal its performance over the China 6 standards and potential to meet the upcoming Euro 7. Three GPF product types (Gen 1, Gen 2, and concept Gen 3) were mounted to the tested vehicle. WLTC tests were conducted on chassis dynamometer in laboratory as well as a self-designed aggressive cycle (“Base Cycle”) tests. To explore the GPFs performance for PN emissions above 10nm against the proposed limit 6.0E11 #/km, PN emission above 10nm were measured in our laboratory tests for both engine out and tailpipe as well as the PN emission above 23nm.