有机酸脂对高原柴油机燃烧特性的影响

Influence of organic acid ester on diesel engine combustion process in plateau environment

针对高原环境下柴油机燃烧恶化的问题,分析了硝酸异辛脂(EHN)的分解途径,通过化学反应动力学分析揭示了EHN添加剂改善柴油机燃烧的机理.利用单缸机台架试验方法研究了进气压力为68kPa、转速为1 400r/min满负荷工况下EHN对柴油机燃烧特性的影响.结果表明:添加EHN能够促进正庚烷反应中自由基OH,H,HO_2和H_2O_2的生成,加速正庚烷的分解,使柴油机着火滞燃期缩短;在低气压进气条件下,随着EHN质量分数的增加,柴油机缸内压力峰值略有下降、放热率曲线前移,柴油机的最大扭矩增加、有效比油耗降低,动力性及经济性均得到改善.

Aiming at the combustion deterioration problem of diesel engine in plateau environment,the catabolism pathway of Isooctyl Nitrate（EHN）was analyzed and its mechanism to improve diesel engine combustion was uncovered by chemical kinetics.A bench test was carried out for the effects of EHN additive on the diesel engine combustion characteristics with the intake pressure of 68 kPa and speed is 1 400r/m.Results show that the generation of OH,H,HO_2 and H_2O_2radicals in n-heptane reaction can be promoted by EHN additive.The n-heptane decomposition is accelerated,thus ignition delay is shortened.Under low pressure inlet condition,cylinder pressure decreases slightly with EHN added in and the curve of heat release rate moves forward.Heat release condition in the cylinder can be improved.In addition,engine output torque increases while specific oil consumption decreases,and the power and economy of diesel engine are improved.