| Oil consumption during the engine operating is inevitable and lubricating oilconsumed in engine will lead to particulate matter (PM) emission deterioration.Besides, the quality of lubricating oil shows great influence on the engine durability,economical efficiency and deposits formation. Meanwhile, the sweepings from theengine wear will lead to the change of PM emission. Therefore, the influence oflubricating oil on the particle size distributions and particle morphology were studiedin a diesel engine with a fast particulate spectrometer and a transmission electronmicroscopy. The effect of lubricating oil quality on the engine wear and depositsformation were studied in an electronically controlled common rail diesel engineoperated under high power density by adjusting the fuel supply parameters. The majorresearch work and achievements of this dissertation are listed as follows:1. Particle size distributions and total number concentrations were investigated witha fast particulate spectrometer when different kinds of lubricating oil were used.Conclusions can be made that during the normal engine operating, the little oilconsumed will influence the particles formation and the conventional oil quality is outof proportion when considering the influence on the particle formation.2. Different proportion of lubricating oil was added into the fuel to investigate theparticles emission change when lubricating oil is involved into the fuel combustion.The results indicate that oil involved into the combustion shows great influence on theparticle formation. The nucleation mode particles emission increased a lot whenlubricating oil is added into diesel fuel.3. Primary particle diameters and distributions were investigated with atransmission electron microscope (TEM) after the oil is added into diesel fuel.Conclusions can be made that the primary particles diameters will grow after the oil isinvolved into combustion, and the result is more obvious when the engine is operatedunder low load. Meanwhile, results from the fast particulate spectrometer show thesame tendency with that from TEM observation.4. Particle size distributions and total number concentrations are investigated whentwo kinds of lubricating oil additives, antioxidant and antifoaming additives and akind of base oil are added into diesel fuel. The results indicate that different kinds oflubricating oil additives show different influence on the particle formation. Because ofthe discrepancy in physical and chemical characteristic, in some cases, the particleformation may even decrease. Lubricating oil quality is evaluated by investigating the deposits formation, abrasion,power change and so on when engine is operated under high power density in oneengine by adjusting oil supply system parameters. Conclusions can be made that theoil quality shows great influence on the deposits formation and engine abrasion. It iseffective and repeatable to evaluate the oil quality when engine is operated under highpower density. |
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