中文摘要：

针对目前柴油机在高排气背压下泵气功损失增加、残余废气系数升高、燃油经济性下降等性能恶化的问题，提出通过优化配气正时来解决此类问题的方案。利用GT‐Power软件对LD1110单缸柴油机建立仿真计算模型，对上述解决方案进行了分析研究。计算结果表明：排气背压为0．3 MPa、进气提前角保持不变、喷油量为45 mg时，柴油机在转速2200 r／min下通过优化排气晚关角可以使平均有效压力提高28．33％，有效燃油消耗率降低22．08％；排气背压由0．1 MPa增大到0．3 MPa时，通过配气正时优化，柴油机在转速2000 r／min下平均有效压力的损失可减小12．8％，有效燃油消耗率的增加可降低27．1％。

英文摘要：

For the problems of larger pump loss ,higher residual gas coefficient and worse fuel economy at high exhaust back pressure ,the scheme of optimizing the valve timing was put forward .With GT‐Power software ,the model of LD1110 single‐cylinder diesel engine was built and the optimization of valve timing was analyzed .The results showed that the brake mean ef‐fective pressure （BMEP） and the brake specific fuel consumption （BSFC） improved by 28 .33% and 22 .08% respectively by optimizing the exhaust late close angle at 2 200 r/min with 0 .3 MPa exhaust back pressure ,45 mg fuel injection per cycle and constant intake valve timing .When the exhaust back pressure increased from 0 .1 MPa to 0 .3 MPa at 2 000 r/min ,the BMEP loss and the BSFC increase could decrease by 12 .8% and 27 .1% respectively .