Experimental Study on the Influence of Injection Timing on Combustion and Emission of Biodiesel Engine Based on Mechanical Mechanics

Abstract

This article investigates the effect of different injection timings on the combustion and emission characteristics of a Chinese V high pressure common rail diesel engine fuelled with blends of biodiesel and diesel (the volume ration of biodiesel is 20%). The Results show that, retarded injection timing resulted in decrease of ignition delay and combustion duration at all loads, except for 25 percent of full load. Peak cylinder pressure and maximum rate of peak pressure significantly reduced at retarded injection timing. The cycle-by-cycle variation of peak cylinder pressure first increased and then decreased, and the highest was obtained at -4°CA of injection timing. BSFC increased by 0.3% to 4.2% with retarded injection timing. Postponing injection timing effectively reduced NOx emission. NOx and PM emissions simultaneously decreased at full load when postponing injection. At 25% load HC and CO emissions were significantly higher than other loads and the effect of injection timing was most obvious.