满足国Ⅳ排放的重型柴油机控制策略设计优化

Design and Optimization of Heavy-duty Diesel Engine Control Strategies to Meet National Stage Ⅳ Emission Regulations

以某重型车用柴油机为研究对象,针对瞬态测试循环(ETC)工况,通过对轨压控制精度、小油门响应和烟度限制等设计优化,提高轨压控制平稳性、系统响应快速性及改善排放性能。试验结果表明:轨压控制精确性得到了提高,在ETC循环部分工况点,样机每秒轨压降减小了42.1%,小油门踏板开度响应速度增加了27.1%,平均消光烟度值降低了72%。最终样机通过了国Ⅳ阶段ETC排放测试,其中NOx排放裕度为27.7%,颗粒物(PM)排放裕度达到了46.7%。

Transient driving cycles for ETC were studied in this paper with a heavy-duty automotive diesel engine.With the development of control functions such as rail pressure precision,response of accelerator pedal with small opening and smoke limitation to improve the stability of rail pressure,system response time and emission performance.The experimental results showed that the precision of rail-pressure control was improved,and some points for circulating ETC,the drop of rail-pressure was reduced by 42.1%,the response time of small opening of accelerator pedal was increased by 27.1%,also the average value of extinction smoke was reduced by 72%.Finally the ETC emission standards of national stage Ⅳ emission regulations had been passed,the NOxemission margin reached 27.7%,and the PM emissions margin reached 46.7%.