RDE 및 시험실 결과의 시험조건 변화에 따른 규제 배출가스 및 온실가스 특성에 관한 연구

Abstract

In this dissertation, the CO₂ GHG and energy efficiency effects of gasoline-powered vehicle under various test conditions were analyzed. The influence of each test condition including ambient temperature and soaking room temperature condition, initial SOC condition, cooling fan wind speed condition, and driving pattern change condition, were compared and analyzed. There was little influence on fuel economy tests due to laboratory temperature, soaking time, or cooling fan conditions. The initial battery SOC condition of the vehicle affected the fuel economy test result by approximately 3 %. Depending on the soft, standard, or rough driving condition, the maximum fuel economy result can differ by up to 5.2 %. The ER, EER, ASCR, and IWR analysis methods were applied with reference to SAE 2951. The sensitivities to the soft, standard, and rough driving conditions are about four times greater in FTP-75 than the HWFET mode. This study conducts exhaust gas correlation test for CVS equipment and particle number (PN) counter equipment for PEMS in the chassis dynamometer. The results are based on the analysis of the real road emissions characteristics. The study evaluates emissions levels between cold and hot start on the chassis dynamometer and perform impact analysis. The functions and specifications of the PEMS equipment are summarized and used as supplementary data for the introduction of regulations. Results showed that correlation between two devices is fairly good, with an error rate of around 10 % for NOx emissions and around 4 % for CO₂ emissions. From results of CPC and DC type particulate number counting device and CVS correlation test, there is little difference between DC and CPC measurement principles. There is a noticeable difference in the initial NOx emissions and CO₂ emission has relatively little impact on cold and hot start conditions. The real road (Cheonan route) NOx emissions using the PEMS test results were found to be slightly less under hot start condition rather than cold start condition, and the difference in NOx emissions in the urban area was remarkable. In the future, the Euro 6c regulation will be applied; it will be the same as the Euro 6 standard, but the vehicle driving mode will be changed from the new European driving cycle (NEDC) to the worldwide harmonized light-duty test cycle (WLTC) and real driving emissions (RDE) will be introduced. Emissions characteristics were measured for passenger diesel vehicles that satisfied different exhaust gas regulation in the Random driving cycles. Emissions characteristics were also analyzed for three different types (DPF, DPF + LNT, and DPF + SCR) of after-treatment system applied to each vehicle. The Random driving cycle generates the driving mode reflecting the characteristics of the test vehicle, so that the same speed region and relative acceleration are distributed as the real road driving conditions. This fully reflects the various acceleration conditions under the real road conditions, which do not appear in the NEDC certification mode. It was found that Vehicle 1 (Euro 5, DPF) increased by 8.8 times more, that Vehicle 2 (Euro 6, DPF + LNT) increased by about 1.5 times more, and that Vehicle 3 (Euro 6, DPF + SCR) increased by about 1.2 times more compared to the NEDC emissions limit. The Random driving cycle applied in this chapter is possible to study real driving emissions (RDE) in the existing chassis dynamometer. It is confirmed that applying the Random driving cycle at the vehicle development stage can result in test cost and development time saving.