汽油-丁醇混合燃料在汽油机中燃烧的数值模拟研究

运用CFD软件模拟了汽油掺混丁醇后的燃烧过程。将丁醇按体积比10%、20%和30%与汽油掺混,研究了这3种混合燃料在不同当量比时缸内温度、缸内压力、放热率和NO排放的情况,并与汽油作了比较。结果表明:燃用B10和B20的发动机缸内温度和缸内压力值均较汽油增大,而B30与汽油的接近。在稀混合气区,混合燃料的放热率均较汽油高;在浓混合气区,混合燃料的放热率较汽油的低。B20和B30在各当量比时的NO排放均较汽油低,B10在稀混合气区低于汽油,在浓混合气区高于汽油。

Numerical Simulation of Combustion of Gasoline-Butanol Blends in Gasoline Engine

This study simulates the combustion process of gasoline-butanol blended fuels.The blended fuels,i.e.B10,B20,B30,mean 10%,20% and 30% butanol are blended with 90%,80%,70% gasoline by volume,respectively.The effect of equivalence ratio on the in-cylinder pressure,in-cylinder temperature,heat release rate and NO emission is investigated.Calculated results indicate that the in-cylinder temperature and pressure for B10 and B20 are both higher than that of gasoline,while the result for B30 is approximate to that of gasoline.In the lean region,heat release rate for blended fuels is higher than that of gasoline,while it is reverse in the fuel-rich region.The NO emissions for B20 and B30 are lower than that of gasoline under all equivalence ratios.However,NO emission for B10 is lower than that of gasoline in the lean region,while it is higher than that of gasoline in the fuel-rich region.