Study On The Combustion And Emission Characteristics Of Diesel Engine Fueled With 2-Methylfuran-Biodiesel Blends

With the rapid development of the automotive industry,energy crisis and environmental pollution has drawn intense attention from all over the world.The replacement of traditional petroleum by bio-fuels may be a promising way to reduce pollutant emission and solve energy shortage.As renewable clean bio-fuels,2-methylfuran?MF?and biodiesel have attracted the extensive attention from the academic world.Although MF and biodiesel are promising bio-fuels,little is known on combustion and emission characteristics of MF–biodiesel blends.In this study,the blends of 0,10%,20%and 30%MF with biodiesel?mass fraction?were referred to as BM0,BM10,BM20 and D30,respectively.Here we studied how the fuel properties and main-injection timing affected the combustion and emission of MF–biodiesel blends or pure biodiesel in a four-cylinder direct-injection compression ignition?DICI?engine.Additionally,The effects of EGR on the combustion and emission characteristics also were investigated experimentally in a diesel engine using BM10.And finally,The effects of pilot injection on the combustion and emission characteristics of the diesel engine fueled with BM20 were simulated by three-dimensional simulation AVL-Fire.The experiment revealed that at low load of 0.13 MPa BMEP,peak cylinder pressure and heat release rate?HRR?are decreased with the increase of MF mass fraction in the mixtures.At 0.38 MPa BMEP,peak cylinder pressure and HRR are increased with the increase of MF mass fraction in the mixtures.At low high of 1.13MPa BMEP,with the increase of DMF mass fraction in the mixtures,there are no significant differences of peak cylinder pressure for four fuels,whilst there is noticeable increase in the HRR.Ignition delay is prolonged with the increase of MF fraction.The combustion duration is curtailed with increase of MF fraction.Additionally,with increase of MF in MF-biodiesel blends,CO₂ and NO_X emissions could be enhanced,while benzene,acetaldehyde,HC,1,3-butadiene,smoke emissions could be reduced.At low loads,the combustions of D30 are unstable and even misfire due to low cetane number and high latent heat of vaporization.Peak cylinder pressure are increased with advanced injection timing.Peak HRR and ignition delay decrease first and then increase with advanced injection timing.The combustion duration increases first and then decreases with advanced injection timing.HC emission decreases first and then increases with advanced injection timing.With advancing main injection timing,1,3-butadiene,acetaldehyde and benzene emissions could be reduced,while NO_X emissions could be enhanced.As the EGR rate is increased,ignition delay and the combustion duration of the diesel engine fueled with BM10 are prolonged.As the EGR rate is increased,NOX emissions could be reduced,while HC,CO,CO₂ and benzene emissions could be enhanced.As the EGR rate is increased,1,3-butadiene and acetaldehyde emission decreases first and then increases.The simulation results show that fuels pilot injection can reduce peak cylinder pressure,HRR,mean temperature and NO emissions.As pilot injection timing is advanced,NO emissions increases slightly first and then decreases.At the pilot injection timing of 20°CA BTDC,BM20 has much least NO emissions.With increasement of pilot injection quality,NO emissions decreases first and then increases.At the pilot injection quality of 20%,BM20 has much least NO emissions.Additionally,With increasement of pilot injection quality,soot emissions is increased.