Transient optimization of a medium duty diesel engine equipped with a high pressure EGR and variable nozzle turbocharger
A medium-duty diesel engine is equipped with a High Pressure EGR (Exhaust Gas Recirculation) and a VNT (Variable Nozzle Turbine) and coupled to an AC Dynamometer. The control of the HPEGR and VNT will be optimized during steady state and transient engine operation to lower nitric oxide and particulate matter production as well as fuel consumption. Brake specific particulate matter, nitric oxide, and fuel consumption will be recorded with fast measurement systems capable of capturing results of transient events. A steady state map of engine speed and load will be used to calibrate initial VNT and EGR control. The calibration will be optimized with a defined formula using emissions production and fuel consumption. After a steady state VNT and HPEGR map is created, the map will be used as a baseline in transient engine operation. The dissertation will contain three parts. Firstly, VNT and HPEGR control assigned via the steady state table will be used during transient events, which will then be increased in speed from a 10 second to a 2 second event. Secondly, the VNT and EGR control will be manually configured in attempt to improve engine performance throughout the transient. Finally, the VNT and EGR control will be applied before the transient event to inspect the effect on engine performance.