压缩比对双燃料发动机中高负荷影响的试验和模拟  

Experimental and numerical investigation of effects of compression ratio on dual-fuel combustion at medium and high load

作　　者：任烁今 张明 郭勇[1] 颜燕[1] 王志[2] 王建昕[2] REN Shuojin;ZHANG Ming;GUO Yong;YAN Yan;WANG Zhi;WANG Jianxin(China Automotive Technology and Research Center CO.,Ltd.,Tianjin 300300,China;State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国汽车技术研究中心有限公司,天津300300 [2]汽车安全与节能国家重点实验室,清华大学,北京100084

出　　处：《汽车安全与节能学报》2020年第4期518-528,共11页Journal of Automotive Safety and Energy

摘　　要：为了解决多缸内燃机双燃料燃烧在中高负荷粗暴燃烧的问题,该文先后采用试验和模拟的方法研究了降低压缩比(CR)对双燃料燃烧中高负荷特性的影响。结果表明:试验中随着压缩比从17.4降低至14.5,均质混合引燃(HCII)燃烧能够达到的最高汽油比例从33%左右上升至54%左右。NOx、碳烟(Soot)和CO排放均能够进一步降低,而碳氢化合物总量(THC)排放则有所增加。模拟中,压缩比降低后汽油组分局部温度降低可达到750 K左右;双燃料燃烧的NOx和Soot主要产生于柴油扩散燃烧区域,随着汽油比例的升高NOx和Soot排放可得到降低;汽油自燃可以有效消除燃烧室狭缝中残留的THC以及汽油不完全燃烧产生的CO排放。总之,通过适当降低压缩比能够在一定程度上改善双燃料燃烧在中高负荷的粗暴燃烧问题,并改善其燃烧排放特性。The rough combustion at the medium and high load has always been a challenge for the dual-fuel combustion.The effects of compression ratio(CR)on the dual-fuel combustion at medium and high load were investigated experimentally and numerically.The experimental results showed that the highest gasoline ratio in homogeneous charge induced ignition(HCII)combustion increased from about 33%to about 54%by reducing the compression ratio from 17.4 to 14.4.As a result,the NOx,soot and CO emissions were further reduced but the total hydrocarbons(THC)emissions got increased.The simulation results showed that the temperature of gasoline could be lowered by about 750 K;The NOx and soot emissions were mainly distributed in the diesel combustion area,and they could be reduced with the increasing gasoline ratio;The THC emissions in the cylinder crevice and the CO emissions generated from the incomplete combustion of gasoline can be eliminatedby the gasoline auto-ignition. In conclusion, the rough combustion at the medium and high load can be alleviatedand the performance of the dual-fuel combustion can be improved by reducing the compression ratio.

关 键 词：内燃机多缸机 双燃料燃烧 压缩比 均质混合引燃(HCII) 汽油比例 数值模拟 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]