高原环境下油品对柴油机燃烧特性的影响研究

摘要

在模拟高原条件下 ,针对3种不同品质的柴油(十六烷值和馏分)对某增压柴油机的燃烧特性的影响规律进行了研究分析 ,并据此简要分析在高原运行时出现活塞烧蚀故障与所用油品的关系.结果显示 :目前在用柴油由于其十六烷值低 ,柴油不易被压燃着火 ,滞燃期长 ,且初馏温度低 ,柴油容易蒸发 ,预混合燃烧期内积累的热量多 ,造成缸内压力的升高速率增大 ,燃烧过程粗暴 ;海拔升高 ,空气密度下降 ,柴油的着火时间延长 ,燃烧速度加快 ,最大压力升高率增大 ,由此产生强烈的热负荷和机械负荷冲击 ,容易造成活塞烧蚀.%The combustion characteristics of turbocharged diesel engine fueled with three types of diesel fuel with different cetane number and distillation were researched at plateau environment and the relationship between piston ablation and fuel property was briefly analyzed . The results show that the fuel with low cetane number and low dropping point leads to difficult compression ignition ,long ignition delay ,ac-cumulative heat in premixing period ,in-cylinder pressure fast increase and even abrupt combustion process .With the increase of altitude ,the atmospheric density decreases ,the ignition period of diesel fuel prolongs ,the combustion accelerates ,and the maximum pressure rise rate in-creases .The intensive thermal load and mechanical load due to the previous factors tend to cause piston ablation .