Evolution of Soot Particle Number, Mass and Size Distribution along the Exhaust Line of a Heavy-Duty Engine Fueled with Compressed Natural Gas

Elia Distaso,Giuseppe Calò,Riccardo Amirante,Pietro De Palma,Paolo Tamburrano

doi:10.3390/en13153993

Elia Distaso, Giuseppe Calò + Show 3 more

Open Access

https://doi.org/10.3390/en13153993

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Journal: Energies	Publication Date: Aug 3, 2020
Citations: 20	License type: CC BY 4.0

Affiliation: Polytechnic University of Bari

Abstract

An experimental study has been conducted to provide a characterization of the transformations that particle size distributions and the number density of soot particles can encounter along the exhaust line of a modern EURO VI compliant heavy-duty engine, fueled with compressed natural gas. Being aware of the particles history in the exhausts can be of utmost importance to understand soot formation and oxidation dynamics, so that, new strategies for further reducing these emissions can be formulated and present and future regulations met. To this purpose, particle samples were collected from several points along the exhaust pipe, namely upstream and downstream of each device the exhaust gases interact with. The engine was turbocharged and equipped with a two-stage after-treatment system. The measurements were carried out in steady conditions while the engine operated in stoichiometric conditions. Particle emissions were measured using a fast-response particle size spectrometer (DMS500) so that size information was analyzed in the range between 5 and 1000 nm. Particle mass information was derived from size distribution data using a correlation available in the literature. The reported results provide more insight on the particle emission process related to natural gas engines and, in particular, point out the effects that the turbine and the after-treatment devices produce on soot particles. Furthermore, the reported observations suggest that soot particles might not derive only from the fuel, namely, external sources, such as lubricant oil, might have a relevant role in soot formation.

Highlights

Many governments around the world have announced their willingness to ban internal combustion engines (ICEs) in a short amount of time
After the three-way catalytic converter (TWC), particle mass (PM) levels are the lowest recorded along the exhaust line, being along the exhaust line, being about one order of magnitude lower than those initially observed about one order of magnitude lower than those initially observed upstream of the turbine
This can be explained by considering the second lowest ones). This can be explained by considering that larger particles can be more that larger particles can be more oxidized by the passage through the TWC, and particles with oxidized by the passage through the TWC, and particles with larger sizes contribute more significantly larger sizes contribute more significantly to soot mass in comparison to particle number (PN)

Summary

Introduction

Many governments around the world have announced their willingness to ban internal combustion engines (ICEs) in a short amount of time. This might suggest that the era of the ICEs has come to an end. Touted as the only possible solution to zero-emissions transport, electric-based mobility does not come without its own set of side effects [5,6,7]. The absence of tailpipe emissions brings the large part of benefits in urban areas (if electricity is generated sufficiently far from the urban center)

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