摘要
为研究进/排气节流对柴油机性能和选择性催化还原(SCR)转化效率的影响,以高压共轨柴油机和氧化催化器(DOC)及SCR组成的后处理系统为研究对象,研究了大气压力为80、90和100 kPa下进/排气节流对柴油机有效燃油消耗率、SCR入口温度和SCR转化效率的影响.结果表明:不同大气压力下,采用进气节流和排气节流均能提高SCR入口温度和改善SCR转化效率,但会导致经济性恶化;进/排气节流程度相同时,进气节流提高SCR入口温度和改善SCR转化效率的效果更好,对经济性影响更小;随着大气压力降低,SCR转化效率增大.因此,综合考虑柴油机经济性和SCR转化效率,建议优先采用进气节流进行柴油机排气热管理;同时,随着大气压力降低,进气压降可适当减小,以提高高原环境下柴油机经济性.
An experiment was conducted on a diesel engine with diesel oxidation catalyst(DOC)and selective catalytic reduction(SCR)exhaust aftertreatment system in order to study the effects of intake and exhaust throttling on engine and SCR performances under different atmospheric pressures.The brake specific fuel consumption(BSFC),SCR inlet temperature and SCR conversion efficiency were analyzed under throttling pressure drop or exhaust back pressure of 80,90 and 100 kPa,respectively.The results show that both intake and exhaust throttling can increase the SCR inlet temperature and improve the SCR conversion efficiency under different atmospheric pressure,but result in an increase of pumping loss and a deterioration of fuel economy.Under the same degree of throttling,the intake throttling shows higher SCR inlet temperature and conversion efficiency and better fuel economy compared to the exhaust throttling method.Meanwhile,the SCR conversion efficiency increases with the decrease of atmospheric pressure.Therefore,the intake throttling method is suggested to apply in the exhaust thermal management of the diesel engine owe to better trade-off of the fuel economy and SCR conversion efficiency.In addition,the degree of intake throttling can be reduced with the decrease of atmospheric pressure,improving the fuel economy when the diesel engine run in plateau environment.
作者
万明定
聂学选
毕玉华
申立中
雷基林
Wan Mingding;Nie Xuexuan;Bi Yuhua;Shen Lizhong;Lei Jilin(Yunnan Key Laboratory of Internal Combustion Engine,Kunming University of Science and Technology,Kunming 650500,China)
出处
《内燃机学报》
EI
CAS
CSCD
北大核心
2023年第3期263-270,共8页
Transactions of Csice
基金
国家自然科学基金重点资助项目(52066008).
关键词
柴油机
大气压力
进/排气节流
燃油经济性
转化效率
diesel engine
atmospheric pressure
intake and exhaust throttling
fuel economy
conversion efficiency
