An Investigation on the Emission Characteristics of Diesel Vehicle with EURO-6 Standard According to Test Mode Including Real-road Driving

Abstract

Emission certification test mode of diesel vehicles in Korea was changed to the WLTC (Worldwide harmonized Light duty driving Test Cycle) mode with RDE (Real-road Driving Emission) test from NEDC (New European Driving Cycle) mode in September 2017. In this study, investigation on the emission characteristics of diesel vehicle with EURO-6 standard according to NEDC, WLTC and RDE test were carried out for validation of the effectiveness in point of controlling NOx emission. The 18 passenger diesel vehicles having EURO-6 standard were selected to analyze the emission characteristics according to various test mode. In addition, test vehicles were sorted according to after-treatment system with LNT (Lean NOx Trap) and SCR (Selective Catalytic Reduction) for the confirmation of emission characteristics by NOx reduction technologies. From the results of emission characteristics, exhaust emissions of all test vehicles show lower levels than the emission standard at tests, except for NOx. However, NOx emissions of some vehicles exceeded the exhaust gas emission limits at the WLTC mode. Also, it was found that vehicles equipped with the LNT as the after-treatment device had a large fluctuation of NOx emission amount according to the test mode but vehicles using the SCR after-treatment system had less change than the LNT vehicle. Key words: On-road emissions, Nitrogen oxides (NOx), Light-duty diesel vehicles, LNT (Lean NOx Trap), SCR (Selective Catalytic Reduction)