Control-oriented modeling of thermal behaviors for a Diesel oxidation catalyst

Diesel oxidation catalysts (DOCs) have become standard components in Diesel engine aftertreatment systems to reduce carbon monoxide (CO) and unburned hydrocarbon (HC) emissions. Intensive studies have been focused on improving the performance of DOCs which has been found to be influenced significantly by its thermal behaviors. The objective of this research is to develop a control-oriented thermal model for a DOC in a DOC/DPF integrated aftertreatment system for real-time control purposes. The control-oriented model is established by considering both the thermal inertia and chemical reactions inside it. The engine-out and DOC-out emissions have been analyzed before simplified empirical models were proposed for the prediction of cared emissions. Experimental validation results show that the control-oriented model is capable of capturing both the gas phase and the solid phase thermal dynamics of a DOC. The control-oriented modeling of the thermal behaviors will be beneficial in integrated engine and aftertreatment system controls.