发动机燃用生物柴油对NO_x排放影响的试验研究

在一台涡轮增压直喷式柴油机上分别燃用生物柴油、掺混油和石化柴油进行试验,对滞燃期、燃烧始点、燃烧压力、燃烧温度、预混燃烧放热规律和扩散燃烧放热规律等燃烧参数对NOx排放的影响进行了研究。结果表明,随着燃料中生物柴油含量的增加,发动机滞燃期缩短,燃烧始点提前,最高燃烧压力增加,最高燃烧温度上升,预混燃烧累积放热率减小,扩散燃烧累积放热率增大;燃烧参数的变化是造成NOx排放升高的主要原因。

Experimental Study on NOx Emission Influenced by Using Biodiesel in Diesel Engine

Tests were carried out on a turbocharged direct injection diesel engine fueled with biodiesel B100,blend fuel B20 and mineral diesel D respectively.Combustion parameters such as the ignition delay period,the start of ignition,the combustion pressure,the combustion temperature,the heat releasing rule of premixed burning and diffusion burning were investigated.The results indicate that with more biodiesel in the fuel,the ignition delay period is shorter,the start of ignition is earlier,the combustion pressure and temperature are higher,the cumulate heat releasing ratio of premixed burning is less while the cumulate heat releasing ratio of diffusion burning is more.Changes of combustion parameters are the main reasons for higher NO_x emission.