摘要
利用GT-Power软件建立直列4缸天然气发动机一维仿真模型,研究不同EGR率对当量比燃烧的天然气发动机的影响。研究表明,随着EGR率的增加,缸内燃烧压力和放热率峰值降低,燃烧过程后移,显著抑制NOx生成,经济性变差;25%负荷时,排气温度上升,HC的排放增加,CO生成量在EGR率超过10%后上升较快;75%负荷时,CO生成量降低,HC生成量在EGR率超过15%后上升速度变快,排气温度在EGR率为17%时达到最高。
A 1-D simulation model of inline 4-cylinder natural gas engine with stoichiometric combustion is built with GT-Power software to explore the influence of EGR ratio on performance of CNG engine with stoichiometric operation.The results show that with the increase of EGR rate, cylinder combustion pressure and heat release peak value decrease,combustion process moves backward, which inhibits the generation of NOx obviously, and fuel economy deteriorates; at 25%load, the exhaust temperature rises, HC emissions increases, CO generation rises rapidly when EGR rate exceeds 10%; at75% load, CO generation decreases, speed of HC generation rises faster after EGR rate exceeds 15%, exhaust temperature reaches the highest when the EGR rate is 17%.
出处
《汽车技术》
北大核心
2015年第12期25-28,共4页
Automobile Technology
基金
吉林省零部件研究开发中心重点项目
