With the increasing focus on black carbon emissions in the International Maritime Organization, It is increasingly important to study the influence of fuel sulfur content on marine diesel engine emission, especially on particulate matter emission, a 4.5 L Marine auxiliary engine was tested with different Fuel sulfur content FSC (0.26% , 0.05% and 0.005%), the effects of fuel sulfur content on the Brake Thermal Efficiency (BTE) were analyzed. And then the variations of conventional and unconventional gas emissions with FSC were measured, such as CO, CO2, CH4, and SO2. Then, based on the difference of the FSN and the PN of PM, the effect of PM morphology was discussed. The results show that with the increase of sulfur content, BTE decreases, CO and THC emissions increase, which are due to the more presence of fuel incomplete combustion products. With the increase of FSC, the fractal dimension(Df) of particle aggregates increases, the rotational diameter(Dg) of particle aggregates increases, more particles are tightly bound together in clusters. So that PN decreases, but FSN increases.
Keywords Fuel Sulfur Content, marine auxiliary diesel engine.