Effect of electric diesel particulate trap on particulate emission characteristics of light-duty diesel engine

Abstract

Based on the principle of corona discharge and electrostatic adsorption, an electric diesel particulate trap (EDPT) with high-voltage negative corona electrode structure was designed. The effect of EDPT on particulate emission characteristics of light-duty diesel engine was investigated based on engine bench test platform. The results show that at the external characteristics operating point of the engine, the trapping efficiency of EDPT for particulate number (PN) is 98.4%, and the trapping efficiency for particulate mass (PM) is 95.0%. With the increasing of exhaust flow, the trapping efficiency of EDPT for PN and PM both decreases slightly. At the load characteristics when engine speed is 1800 r·min−1, the trapping efficiency of PN and PM by EDPT are 98.9% and 95.1%, and the trapping efficiency does not change significantly with the increase of load and temperature. The effects of EDPT and DOC (Diesel oxidation catalyst)+diesel particulate filter (DPF) device on engine backpressure and particulate trapping efficiency are compared. The results show that the effect of using EDPT on engine exhaust backpressure is much lower than DOC+DPF, and the trapping efficiency for PN and PM is lower than that of DOC+DPF. From the perspective of trapping efficiency and device size, EDPT is more suitable for the exhaust gas treatment of construction machinery, agricultural machinery and factory fixed source diesel engines.