A JCAP study on the effects of vehicle technology and fuel properties on the diesel engine emissions

摘要

The plan and results concerning diesel emission in the model step of the Japan Clean Air Program (JCAP) are reported. In the first step of JCAP, 8 diesel vehicles and 7 diesel engines (all commercially available) are tested with 5 fuels in the testing step known as the "existing step". After the existing step, the model step is carried out. In the model step, the emission tests are carried out for engines equipped with oxidation catalysts, DPF, and engines in which fuel sensitivity shows maximum or minimum in the existing step. Eight specially prepared fuels are used in the model step. These fuels are different in distillations, sulfur contents, and aromatic contents. They are made from a blend of several hydrocarbons so that distillations and composition can be varied independently. DPF effectively reduces particulate matter. Oxidation catalyst is effective in reducing SOF in particulate matter, unburned HC, CO, aldehydes and other un-regulated pollutants, although a strong oxidation catalyst requires low sulfur fuel to avoid excessive sulfate emission.