Experimental study on effects of pilot injection mass strategy on combustion, Performance and emission characteristics of CRDI Engine

Abstract

This experimental work reports how different pilot masses of biodiesel-blended fuel in Common Rail Direct Injection (CRDI) engines affect engine performance, combustion, and emissions. This experiment used 20MEWCO (20 % Methyl Esters of Waste Cooking Oil + 80 % Diesel) as the test fuel. Several parameters, such as timing and injection mass, affect how the CRDI system delivers fuel. In this work, the pilot injection mass was varied by 5 %, 7.5 %, and 10 %, keeping other factors such as injection pressure at 500 bar and the timing of the pilot and main injections at 36°Crank Angle before Top Dead Centre (bTDC) and 15°Crank Angle before Top Dead Centre (bTDC), respectively. This work reveals that when pilot mass is increased in steps of 2.5%, the combustion performance parameters like cylinder pressure, heat release rate and specific fuel consumption values decrease. Also, it gave off less smoke, carbon monoxide and hydrocarbons than regular diesel with more nitrous oxide. Also, it was found that at 10 % of the pilot mass, carbon monoxide, hydrocarbon, and smoke emissions were significantly reduced, with a slight rise in oxide of nitrogen emissions at the same time, without affecting the engine performance.