Study On Combustion And Emissions Performances Of Common Rail Diesel Engine Burning Oxygenated Fuel/F-T Diesel Compoun Fuel

Coal chemical industry of our country has developed rapidly,more and more enterprises have mastered the technology of making liquid clean fuel by coal,which can be used in a large quantity of coal into liquid synthetic fuel and can be directly applied to diesel engine,that is F-T diesel.Compared with 0# diesel,F-T diesel has the advantages of high cetane,high c(H)/c(C)and so on,which can reduce the emission of NO_X and soot,but the reduction of emissions is limited.The addition of alcohols,ethers and lipid fuels to F-T diesel can reduce emissions further and realize the synchronous reduction of NO_X and soot.Therefore,we put low proportions methanol,PODE and DMC into F-T diesel.Adding oxygenated fuel to F-T diesel,it is necessary to study the intersolubility and stability of mixed fuel.F-T diesel with PODE and DMC have good intersolubility when the mixing ratio is low,but it can not dissolve with methanol.Therefore,the mixture of methanol and F-T diesel fuel needs solvent.After the experiment,we chose Decyl Alcohol as a cosolvent.Preparation of 10% volume ratio of alcohol,ethers and lipid oxygenated fuel mixture.Compared with F-T diesel,the dynamic viscosity,cetane number,c(H)/c(C)changed little by measurement and calculation.Volume of the low calorific valueand mass of the low calorific value decreased slightly,and the density and oxygen content increased slightly.The changes of these physical and chemical properties would affect the performance of the diesel engine directly.After oxygenated mixed fuel was used in a high pressure common rail diesel engine(YN33CRD1),the effects of oxygenated mixed fuel on the combustion characteristics,dynamic economy and emission characteristics were analyzed.The high cetane of oxygenated mixed fuel makes the ignition delay shorter than the 0# diesel and longer than the F-T diesel,and there is no obvious change in rapid combustion period,normal combustion period is longer than 0# diesel and shorter than F-T diesel,the differenceof post combustion period is small.The peak value of the cylinder pressure,the peak of combustion heat release rate and the combustion temperature in the cylinder of F-T diesel lower than the 0# diesel,the peak value of the combustion heat release rate is ahead of time and the maximum temperature of the combustion process decreases.Compared to F-T diesel,dynamic economy performance of M10,P10 and D10 mixed fuels have been reduced,which is mainly related to the lowvolume of the low calorific value and mass of the low calorific value.The oxygenated mixed fuel with F-T diesel as the base fuel increases the oxygen content at the same time that the fuel have high cetane,and the emission of soot and NO_X can be reduced at the same time,the trade-off problem solution is well solved.Its oxygen content also reduces the CO emissions,and the use of oxygenated mixed fuel will also increase emissions of HC,methanol,formaldehyde and other emissions.In order to study the performance between the 0# diesel and the F-T diesel in different engine(mechanical injection diesel engine and high pressure common rail diesel engine),0# diesel and the F-T diesel were used respectively for the mechanical injection diesel engine and the high pressure common rail diesel engine.It was found that when the fuels was used in the mechanical injection diesel engine,the dynamic economyof F-T diesel was inferior to 0# diesel,and the emission characteristics were better than 0# diesel.But when the fuels was used in high pressure common rail diesel engine,the power performance of F-T diesel is similar to 0# diesel,and its economy and emission characteristics are better than 0# diesel.F-T diesel burning in the high pressure common rail diesel engine can play its performance advantage more.Through the analysis of the related experimental data of 0# diesel,F-T diesel and oxygenated mixed fuel,it is found that adding oxygenatedfuel to F-T diesel can reduce the emission further and reduce the emission of soot and NO_X simultaneously.The addition of oxygented fuel to F-T diesel fuel is an effective means to reduce the emission.