Modelling of an EGR System

Abstract: Due to new emission legislations in Europe and in the USA truck manufacturers are facing new difficulties when it comes to meeting these demands. This new legislation will demand more accurate models for simulation and malfunction diagnosis. The NOx emissions, covered in these new laws, are intimately linked to combustion temperatures and these temperatures may be decreased by means of exhaust gas recirculation into the intake air, so called EGR. This thesis deals with alternative EGR mass flow estimation models in a 13-litre Volvo diesel engine equipped with turbo and variable geometry turbine. Using a mean value model and moving average filtered temperature, EGR valve position and pressures as inputs this estimate however, never touches the current EGR mass flow estimation in mean and maximum relative errors. Validation is by stationary inputs but dynamic simulations are examined.