Particulate Emissions from a China V Heavy-Duty Diesel Engine with Ultra Low Sulfur Diesel Fuel and DOC+CDPF+SCR 2017-01-0914
Since diesel engines have higher thermal efficiency, superior power capability and better fuel economy than gasoline engines, diesel engines are widely used in vehicles, construction machineries and agricultural machineries. However, they emit more hazardous pollutants than gasoline engines, especially particulate emissions, which have negative impacts on human’s health and air quality in cities. In order to meet future increasingly stringent regulations for particulate emissions, exhaust gas aftertreatment technologies for diesel engines are essential. Particulate emissions from a heavy-duty diesel engine which meets the China national V emission regulation were studied, and the engine was equipped with/without diesel oxidation catalyst (DOC), catalyzed diesel particulate filter (CDPF) and selective catalytic reduction (SCR). The fuel used in this article is ultra low sulfur diesel fuel whose sulfur content is less than 10 ppm. A TSI 3090 Engine Exhaust Particulate Sizer was used to study the number and size distribution of particulate emissions. Results show that with the increase of engine load, the total number of particulate emissions increases, and especially under high engine load, the increase of total particulate number is drastic in consequence of the deterioration of combustion in the cylinder. Compared with the engine without exhaust gas aftertreatment devices, DOC+CDPF+SCR can evidently reduce the particulate number by 1~2 orders of magnitude, and the decreasing range can up to 2~3 orders of magnitude when the particulate diameter is between 10~60 nm. At the maximum torque speed of 1400 rpm and rated speed of 2200 rpm, the filtration efficiency of total particulate number from the engine can be over about 95%.