Combustion analysis of a light duty diesel engine using oxygen-enriched and humidified combustion air

¹ Università degli Studi di Milano, Dipartimento di Chimica, Milano, Italy
² Università di Modena e Reggio Emilia, Dipartimento Ingegneria “Enzo Ferrari”, Modena, Italy
³ Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Milano, Italy
⁴ Università di Modena e Reggio Emilia, Dipartimento di Scienze e Metodi per l’Ingegneria, Reggio Emilia, Italy

^* Corresponding author: carloalberto.rinaldini@unimore.it

Abstract

The present work presents the results of 3D CFD combustion simulations of a current production 4-cylinder turbocharged Diesel engine using oxygen-enriched and humidified combustion air. Enriched Air (EA) is supposed to be produced by desorption from water, exploiting the different Henry constants of N₂ and O₂. Simulation results show that EA permits to increase the engine thermal efficiency (up to 10%) and drastically reduces soot emissions but increases in-cylinder peak pressure and NO_x emissions. Combustion air humidification helps to reduce NO_x increment, without losing the advantage in terms of thermal efficiency and in soot reduction, even if NO_x emissions cannot be reported to the base case values.