大负荷下柴油-天然气双燃料发动机燃烧特性数值模拟  

Numerical Simulation Study on Combustion Strategy of Diesel-Natural Gas Dual Fuel Engine Under High Load

作　　者：张光德[1] 罗露 宋巍[1] 张嘉诚 ZHANG Guang-de;LUO Lu;Song Wei;ZHANG Jia-cheng(School of Automobile and Traffic Engineering,Wuhan University of Science and Technology,Hubei Wuhan 430081,China)

机构地区：[1]武汉科技大学汽车与交通工程学院,湖北武汉430081

出　　处：《机械设计与制造》2022年第3期105-109,113,共6页Machinery Design & Manufacture

基　　金：湖北省自然科学基金重点项目(2015CFA113)。

摘　　要：为提升柴油-天然气双燃料发动机在大负荷工况下的动力性、经济性和排放性等多种性能,利用某商用软件建立发动机三维气缸模型,探究了二次喷油策略下柴油的喷射时刻对发动机燃烧与排放的影响。研究表明,一定范围内较早的主、预喷时刻可以提高发动机的缸温、缸压、IMEP、燃烧效率等参数,使燃料燃烧更加充分,缸内温度分布更加均匀,并能实现较高的热效率和较低的排放。但是过早的主、预喷时刻会导致燃烧不充分,燃烧效率降低、发动机的性能减弱并产生大量废气等负面影响,由此可见,大负荷下适当提前引燃柴油的喷射时刻可优化燃烧,降低大负荷工况下的爆燃倾向,提高发动机的动力性和经济性,稳定燃烧过程。In order to improve the performances of diesel-natural gas dual fuel engine under high load condition,such as power,economy,emission and so on,the three-dimensional cylinder model of the engine was established based on a commercial software. The influence of diesel injection time on engine combustion and emission under the second injection strategy was investigated. The results have shown that the earlier main and pre-injection time within a certain range can improve the cylinder temperature,cylinder pressure,IMEP,combustion efficiency and other parameters of the engine,making the fuel burn more fully,the temperature distribution in cylinder more uniform,and can achieve higher thermal efficiency and lower emissions. However,premature main and pre-injection time will lead to inadequate combustion,reduce combustion efficiency,weaken engine performance and produce a large number of exhaust gas and other negative effects. It can be seen that the injection time of appropriately initiating diesel fuel in advance under heavy load can optimize the combustion,reduce deflagration tendency under heavy load conditions,improve the dynamic performance and economy of the engine,and stabilize the combustion process.

关 键 词：柴油-天然气 发动机 大负荷 燃烧策略 二次喷射 

分 类 号：TH16[机械工程—机械制造及自动化] U461.8[机械工程—车辆工程]