Experimental Study the Influence of EP Antiwear Additive on Particle Emissions in Diesel Engines 2013-01-1566

We studied the influence of extreme pressure (EP) antiwear additive on the emission and distribution of particulate matters (PMs), since EP antiwear additive is necessary to improve the property of lubricating oil with the downsizing development of engines. We used a four-cylinder, turbocharged, and inter-cooled system with SAE15W-40 lubricant diesel engine. Pure diesel and fuel blends with varying weight percentages (0.5%, 1.0%, and 1.5%) of EP antiwear additive were used. Engine speed increased by increments of 400 from 1,200 rpm to 2,800 rpm under medium load and full load. The DMS500 was used to acquire particle data, and the Wave Book was employed to record oil and cylinder pressure. Conclusions drawn from the experiments suggest that EP antiwear additive has significant effects on PM emissions and distributions. Increments and decrements were observed on the number of accumulation mode particles and nucleation mode particles with BDAW-0.5. By contrast, the number of nucleation mode and accumulation mode particles increased when BDAW-1.0 and BDAW-1.5 were burned. The deterioration of accumulated PM enables the absorption of nucleation mode particles; however, the absorption capacity is limited. Thus, the emission of nucleation mode particles was optimized even though the number of accumulation mode particles increased with BDAW-0.5 and deteriorated with BDAW-1.0 and BDAW-1.5. The sulfur content in EP antiwear additive can affect the emission of nucleation mode particles. Furthermore, the high viscosity and flash point of EP antiwear additive can reduce volatility and atomization, significantly influences the emission of accumulation mode particles.