两次喷射对正丁醇部分预混燃烧影响的试验研究

摘要

在一台改造的单缸柴油机上进行了预主喷两次喷射策略对正丁醇部分预混燃烧影响的试验研究.研究结果表明:正丁醇燃料实现部分预混燃烧相对汽油燃料对喷射时刻较敏感,最大压力升高率高,稳定运行范围窄,但未燃碳氢、氮氧化物和碳烟排放较低;预主喷两次喷射能有效降低正丁醇部分预混燃烧最大压力升高率,随着预主喷间隔的增大,最大压力升高率先快速降低后上升,预喷射比例越大,获得最低压力升高率对应的预主喷间隔越大;通过优化预主喷两次喷射策略,能显著改善正丁醇部分预混燃烧可控性差、最大压力升高率高的问题,从而有利于实现更大工况范围内的高效燃烧.%An experimental investigation on the partially premixed combustion(PPC)of neat n-butanol by using the two-stage injection strategy has been conducted.The results indicate that compared to the gasoline PPC,the n-butanol PPC is more sensitive to the injection timing,and the stable operation scope is narrower due to the higher pressure rise rate (PRR),but the THC,NOxand soot emissions are lower.On the other hand,the two stage injection strategy can effectively reduce the PRR.As the interval between pilot injection and main injection increases,the PRR firstly reduces rapidly and then increase eventually.With the higher pilot injection ratio,the longer interval control method should be adopted to reduce the PRR.By using the optimized two stage injection strategy,the poor controllability can be significantly improved,which is beneficial to achieve the high efficient combustion on a broader operation scope.