Experimental Study On N-Pentanol/Biodiesel/Diesel Blended Fuel Combustion

N-pentanol and biodiesel are both new diesel fuels for diesel and we used them to replace some diesel fuel in order to reduce diesel consumption.The study shows that biodiesel has a significant effect on reducing Soot,but the viscosity of the biodiesel is higher and the atomization performance is poor.The high pressure common rail system of diesel engine with large spray pressure can easily cause wall and wet wall.In order to improve the physicochemical properties of biodiesel/diesel fuel mixture,the pentaerythritol was added into the blended fuel.In order to study the effects of blended fuel on engine combustion and emissions.The experimental oil:pure diesel(denoted D100),diesel blended with20%biodiesel by volume(denoted DB20),and DB20 blended with 20%n-pentanolby volume(denoted DBP20).The results shown that,①under the middle and low loads,with the increase of BMEP,Soot was on the decline.Under the high load,with the increase of BMEP,Soot was on the rise.Adding n-pentanol,Soot emission of DBP20 reduces further than BD20.②As the EGR ratio increased,NOx emission effectively reduced.At the middle and low ratios(<20%),as the EGR ratio increased,Soot didn’t increase obviously.When the EGR ratio>20%,as the EGR ratio continued to increase,Soot,CO and THC surge in emissions.Compared with D100,Soot emission of DB20 reduced obviously,NOx emission had no obviously change,THCemission obviously increased and COemission decreased slightly.Compared with D100,Soot and NOx emission of DBP20 decreased,CO and THC surge in emissions when the EGR ratio was large.As the EGR ratio increases,the nucleation particle number decreased at first and then increased.The aggregation state increased with the increase of EGR,and increases significantly when EGR is greater than 25%.The changes in the concentration of total particle number concentration in the three types of fuel were similar,both of which were lower and then higher.③Under the same injection interval,as in the process of the injection ratio increased,the peak in-cylinder pressure and the peak of heat release for pilot injection increases.Under the same injection quantity in advance,as the injection interval increase,the maximum pressure and in-cylinder temperature has declined slightly,the peak of heat release for pilot injection down.Diesel blending 20%biodiesel,and diesel cylinder pressure curve and heat release ratio curve,there is no obvious change compared DBP20 compared with the D100,cylinder pressure,heat release ratio curve is larger,mainly reflects in:the peak of heat release for pilot injectionratio reduced and shift to the right,the peak of heat release rate for the main-injection phase,exothermic starting point to the right offset,longer ignition delay period,the peak of in-cylinder pressure had no obvious change,but the peak pressure moved after a moment.After the addition of oxygen-containing fuel;The effective thermal efficiency is reduced,and the specific performance is:DBP20<DB20<D100;The combustion efficiency is not obvious compared with pure diesel;④With the increase of injection pressure,the number of nucleate particles in the three types of fuel increased and the accumulation number concentration decreased.The total particle number of the three kinds of fuel was reduced.In the same injection pressure,the total particle number from high to low is:DB20>DBP20>D100;The total particle number concentration of the three kinds of fuel is reduced.Under the same injection ’pressure,the total particle number from high to low is:DB20>D100>DBP20.