Modelling for Control of Exhaust Gas Recirculation on Large Diesel Engines

Exhaust Gas Recirculation (EGR) reduces NOx emissions by reducing O2 concentration for the combustion and is a preferred way to obtain emission regulations that will take effect from 2016. If not properly controlled, reduction of O2 has adverse side effects and proper control requires proper dynamic models. While literature is rich on four-stroke automotive engines, this paper considers two-stroke engines and develops a non-linear dynamic model of the exhaust gas system. Parameters are determined by system identification. The paper uses black-box nonlinear model identification and modelling from first principles followed by parameter identification and compares the results of these approaches. The paper performs a validation against experimental data from a test engine and presents a linearised model for EGR control design.