Abstract
Due to rising public concern about the real driving emissions from Diesel powered vehicles, the Indian authorities have enacted strict legislative requirements to reduce tailpipe emissions for improvement of ambient air quality. Concurrently, the improvement in engine efficiency has also become a focus of development, due to not only the fuel economy legislation (CAFE) and Green House Gas (GHG) emissions, but also aiming for low operating costs, as it is a decisive selling aspect in the fast growing Indian market. To meet these partially competing requirements, new technology packages are mandatory to ensure robust compliance with the emission legislation as well as the requirements of end users. In India, by 2020, the BS VI (Bharat Stage VI) emission standards will become applicable, still using the well-known Modified Indian Driving Cycle (MIDC) certification procedure. However, as the next step (year 2023), Real Driving Emission (RDE) test procedures are planned to be implemented, derived from the already enacted EU legislation. This paper presents FEV’s powerful mean value powertrain simulation tool-chain focusing on robust RDE compliances for typical passenger car segment Diesel applications. Under the framework of this study, different emission control pathways focusing on the engine and exhaust aftertreatment interaction and optimization loops are analyzed. This approach is exemplarily demonstrated for a typical popular 2.0L class Diesel SUV application. Initial results determine that the operation of the base engine configuration (with MIDC calibration) within WLTC and RDE cycles results in a multifold increase (~ 3 to 6 times) in terms of EO (engine out) NOx emissions, and up to 19% increase in terms of F.C./ CO2. Based on the system optimization results, it could be concluded that a base BS VI MIDC engine is possible to be upgraded for robust RDE compliance (aiming at robust conformity factors of = 1.25) with a combination of practical, cost effective and series production oriented technological upgrades such as the introduction of Start-Stop, improved air and fuel path calibration, application of optimized EGR systems and simplified but well-engineered SCR based Exhaust Aftertreatment Systems (EATS).