Dynamic modeling of a lean NO/sub x/ trap for lean burn engine control

Abstract

A control oriented dynamic model of the lean NO/sub x/ trap (LNT) behavior has been developed in SIMULINK/sup TM/. The model simulates the trapping and purging phenomena and includes the important parameters which affect the LNT behavior. These include the trap temperature, trapping and purging duration, air/fuel ratios and the mass flow rates of the exhaust gases. Engine dynamometer test data have been used to identify the model parameters and to validate the model structure. There is good agreement between the simulation results and test data. The model is suitable for control and fuel/emission tradeoff analysis.