Modelling and simulation of virtual NOx sensor for diesel engine using thermodynamic model

Abstract

This paper presents a thermodynamic model for virtual NOx sensor which is capable of predicting nitrogen oxides (NOx) emissions in diesel engines. In-cylinder volume and pressure are the inputs from estimator. The proposed method is based on a two-zone thermodynamic model which divides the combustion chamber into burned and unburned gas zone. The contribution of proposed method arises from: In-cylinder volume and pressure are the inputs from estimator using slider crank mechanism. And the two-zone thermodynamic modeling framework is applied in a way that the thermodynamic equations can be solved in a closed form, which provides the basis for achieving high level of predictiveness using MATLAB which uses ADVISOR as prerequisite for the project. The model is validated using real data values. The model is suitable for two different direct injection diesel engines, i.e. a light and a heavy-duty engine. Also, it maintains a low pipe emission which minimizes fuel consumption.