Role of lubricating oil properties in exhaust particle emissions of an off-road diesel engine 2020-01-0386
Particle number emissions from an off-road diesel engine without exhaust after-treatment were studied by using five different heavy-duty lubricating oils in the engine. The study extends understanding how the properties of lubricating oil affect the emissions of the smallest nanoparticles from a modern off-road diesel engine. The lubricants were selected among the performance classes of the European Automobile Manufacturers Association, at least one lubricant from each category intended for heavy-duty diesel engines. Particle size distributions were measured by means of an engine exhaust particle sizer (EEPS), but particle mass emissions, soot emissions, gaseous emissions and the basic engine performance were also determined. During the non-road steady cycle, the most of the differences were detected at the particle sizes of 6–15 nm. In most cases, the lowest particle quantities were emitted when the highest performance category lubricant was used. Based on the results of this study, the low contents of Zn, P, and S in lubricating oil contributed to the reduced emission factors for engine-out nucleation mode particles at any load. In addition, the low content of sulfate ash was considered the one main influential factor for the low particle number emissions.
Teemu Ovaska, Seppo Niemi, Katriina Sirviö, Olav Nilsson, Panu Karjalainen, Topi Rönkkö, Kari Kulmala, Jorma Keskinen
University of Vaasa, Tampere University, Neste Corporation