Emissions from a Legacy Diesel Engine Exercised through the ACES Engine Test Schedule

Most transient heavy duty diesel emissions data in the USA have been acquired using the Federal Test Procedure (FTP), a heavy-duty diesel engine transient test schedule described in the US Code of Federal Regulations. The FTP includes both urban and freeway operation and does not provide data separated by driving mode (such as rural, urban, freeway). Recently, a four-mode engine test schedule was created for use in the Advanced Collaborative Emission Study (ACES), and was demonstrated on a 2004 engine equipped with cooled Exhaust Gas Recirculation (EGR). In the present work, the authors examined emissions using these ACES modes (Creep, Cruise, Transient and High-speed Cruise) and the FTP from a Detroit Diesel Corporation (DDC) Series 60 1992 12.7 liter pre-EGR engine. The engine emissions were measured using full exhaust dilution, continuous measurement of gaseous species, and filter-based Particulate Matter (PM) measurement. Run-averaged brake-specific emissions varied between modes, partly because the average power varied between modes. However, the relationship between the mass rate of oxides of nitrogen (NO_x) production and engine power was similar for each mode, implying that NO_x data could be translated between modes. Unfortunately, emissions of carbon monoxide and particulate matter are dependent on transient behavior and are not readily translated between modes. Individual trips from the modes have been examined separately, sorted by average power, and their emissions have been compared. Linear models for the NO_x emissions have also been developed to verify the consistency of data from the various modes.