NO x Emission prediction based on measurement of in- cylinder pressure for CI engine running with diesel and biodiesel

Abstract

NOx is one of the major toxic emissions that needs to be regulated stringently in both EU and USAemission regulations. The engine designer is keen to get an accurate, reliable and cost effective NOxmeasurement system. In this paper, the application of the cylinder pressure for predicting the NOxemission of compression ignition (CI) engine fuelled with diesel and biodiesel during steady stateoperations is carried out. To address the problem, an experimental work was conducted on four -cylinder,turbo -char ged, four -stroke and direct- injection CI engine which was fuelled with diesel and biodieselblends. During the experiment, the main parameters consisting of in-cylinder pressure, fuel flow rate,air flow rate, and the NOx emission, were measured. The temperature within the cylinder was predictedusing the cylinder pressure and air flow rate. Using the temperature values, the NOx emission wassimulated in the Zeldovich extended mechanism. The simulation result was then compared with themeasured one for a range of engine operating conditions. The model s were shown to produce consistentresults with the measured one for a range of engine working speeds and loads.