Real-Time Measurement of Particle Size Distribution From Diesel Engines Equipped With Continuous Regenerative DPF Under a Transient Driving Condition

Abstract

A new PM measurement method, such as particle measurement equipments, samplings and so on, is being studied at present for a type approval test in the future. Particles emitted from diesel engines, especially the particles that are called Nuclei Mode Particles are very unstable and easily influenced by the engine operating conditions and the measurement conditions. Most of nuclei mode particles are said to consist of volatile organic particles with mainly high carbon numbers. It is said that a continuous regenerative type DPF (Diesel Particulate Filter) consisting of oxidation catalyst and ceramic filter will prevail in the near future. These particles may be able to be reduced by an oxidation catalyst in this DPF. The objectives of this study is to investigate the behavior of nuclei mode particles in DPF (CRT, Continuous Regenerative Trapper) that will prevail and to clarify the collection performance of DPF for nuclei mode particles by using a fast particle sizer (DMS500) which can measure particle size distributions in real time. The transient particle size distribution behaviors were measured in real time by DMS500. It was shown that an oxidation catalyst in CRT reduced nuclei mode particles in the condition of more than 200 Celsius degree exhaust gas temperature but did not reduce them in less than 200 Celsius degree. The particle number concentrations reduced to about 1/100 by DPF.