Particle Number Emissions During Regeneration of DPF-equipped Light Duty Diesel Vehicles - a Literature Survey

摘要

The study reviews published work on the particle emissions during regeneration of diesel particulate filters in an attempt to assess the PMP methodology under these operating conditions. During regeneration of the DPF a significant increase of the emitted number of particles is observed. Size spectra reveal a nucleation mode peaking at approximately 10 nm, at concentrations that can exceed the emission levels under non-regenerating conditions by more than three orders of magnitude. These nano-sized particles are found to be mostly volatile in nature with their concentrations correlating with the sulphate content of the emitted particulate matter. Particle number measurements following the PMP methodology are found to be little affected by this burst of nucleation mode particles, partly because of the large cut-off size of the CPC (23 nm) and partly because of the semi-volatile nature of the emitted nanoparticles, exhibiting more than 97% overall removal efficiency.