A simulation study of the optimal operating conditions of fuel injection for an agricultural direct injection diesel engine

Abstract

Emission reduction and performance improvement for non-road engines are recently interested in the viewpoint of protecting environment, meeting the strict emission standard, and enhancing the performance characteristics. This paper presents a simulation study on the optimal operating conditions for better performance and emission characteristics of small direct injection diesel engine for agricultural purposes. In order to study the optimal operating conditions of fuel injection in an agricultural direct injection diesel engine for better performance and emission characteristics, the injection timing and injection pressure are graduately changed in a wide range by using the simulation method. Model of a single cylinder diesel engine is created by an advanced thermodynamic simulation tool AVL BOOST and verified by some experimental results. Injection timing is varied from 24 degree in crank angle (°CA) before top dead center (bTDC) to 4°bTDC by a step of 2°CA. Change of injection pressure is from 160 bar to 240 bar by a step of 20 bar. The engine performance characteristics (such as: power, torque, specific fuel consumption, emission conposition of CO, NO., Soot) are studied and estimated qualitatively and quantitatively. The obtained results show that the optimal injection timing and injection pressure for better engine performance are founded to be between 12 and 16°bTDC and 220 bar, respectively. The major emissions are decreased significantly while engine power is reduced about 5% and increase of specific fuel consumtion is about 5%.