Study On Combustion And Emission Characteristics Of A Direct-injection Gasoline Engine Using Biobutanol Fuel

With the quick development of China's automobile industry,people's demand for cars is increasing.Meanwhile,the energy and environmental problem are also obvious.In recent years,China has become more and more dependent on foreign oil,which seriously restricts the development and threatens the security of China.Therefore,finding a new type of renewably clean energy has become a top priority.The performance of n-butanol is close to that of gasoline,so it has attracted more and more researchers'attention.The rapid development of computer science has enabled the realization of engine simulation calculations.The cycle of engine simulation calculation is short,the research and development cost is low,and the simulation accuracy can meet the experimental requirements.Therefore,it is recognized by many scientific researchers.In this paper,GT-Power simulation software was used to establish a 1-D engine simulation model to simulate engine operation,and combustion and emission performance of the engine are obtained by analyzing the calculation results.CFD simulation software was used to simulate the gas flow and knock combustion in the engine cylinder.The 1-D engine model mainly simulates engine performance,and the 3-D engine model mainly simulates engine combustion and species changes.Combining 1-D and 3-D engine models makes more accurate simulations of engine combustion and emissions.The main research contents of this article are four parts:the effect of n-butanol-gasoline blends on engine combustion and emissions;the effect of pure n-butanol on engine combustion and emissions;compare and analyze the combustion and emission performance of methanol,ethanol and n-butanol in an engine;knock analysis of n-butanol in a GDI engine.The analysis of these four parts lays a certain foundation for the application of n-butanol fuel in internal combustion engines.The results indicate that the addition of n-butanol fuel to gasoline can increase the engine torque,improve the BTE of the engine,and reduce the NO_x and CO emissions of the engine.When pure n-butanol fuel is used in the engine,the engine uses a standard mixture to ignite at about 10°CA BTDC,and at the same time,and the overall performance of the engine is best when the flame kernel radius is reduced.Compared with methanol and ethanol,n-butanol is used in the engine,the BSFC is lower,and NO_x and HC emissions are lower.When studying the knock combustion of n-butanol fuel in an engine,adding EGR to the engine can better reduce the combustion temperature and HRR to suppress engine knock.However,higher EGR rates will result in increased engine knock.CO₂ and H₂O in EGR play an important role in suppressing knock.In summary,n-butanol has good performance,can improve the power performance and BTE,and can also reduce engine exhaust emissions.It is a relatively promising alternative fuel.