摘要
在废气再循环(EGR)和稀燃策略下,以一台进气道喷射点燃式大功率甲醇发动机为试验对象,研究了两种稀释策略及复合稀释对甲醇发动机性能、燃烧及排放特性的影响。试验结果表明:在相同的稀释率下,稀燃比EGR能拥有更高的缸压峰值、更短的燃烧持续期、更低的燃油消耗率和更高的有效热效率。稀燃策略在降低HC和CO排放方面效果较为显著,而EGR策略能更为有效地降低NO_(x)排放。在未燃甲醇和甲醛排放方面,稀燃策略效果都较好。与EGR单独稀释相比,复合稀释能显著提高甲醇发动机的有效热效率。复合稀释对HC排放的影响较小,在降低CO排放方面和过量空气稀释效果相似,优于EGR稀释,最大降低幅度高达80.3%;拥有更好的抑制NO_(x)排放的效果,最大降低幅度为97%。复合稀释时,未燃甲醇排放与EGR单独稀释时相当,高于过量空气单独稀释;高稀释程度复合稀释时,甲醛排放有所下降。
Under the exhaust gas recycling(EGR)and lean-burn strategy,the effects of two strategies and compound method on performance,combustion and emission characteristics were studied based on a high-power methanol engine with injection ignition in the inlet port.The test results show that lean-burn can have higher cylinder pressure peak,shorter combustion duration,lower fuel consumption and higher effective thermal efficiency at the same dilution rate.Lean-burn strategy is more significant to reduce HC and CO emissions,but the EGR strategy can more effectively reduce NO_(x) emission.In terms of unburned methanol and formaldehyde emissions,the lean-burn strategy has the better effect.Compared with EGR alone,compound dilution can significantly improve the effective thermal efficiency of methanol engine,has little influence on HC emission,can reduce CO emission by 80.3%at the largest that is similar to the excessive air dilution and better than EGR,can suppress NO x emission with a maximum reduction of 97%,but has an equivalent effect on unburned methanol emission that is higher than the excessive air dilution.When the compound dilution with a high degree is applied,formaldehyde emission will slightly reduce.
作者
孟雨航
孙楠楠
张明泽
贾德民
张海燕
朱建军
MENG Yuhang;SUN Nannan;ZHANG Mingze;JIA Demin;ZHANG Haiyan;ZHU Jianjun(College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Weichai Power Co.,Ltd.,Weifang 261061,China)
出处
《车用发动机》
北大核心
2023年第6期10-18,83,共10页
Vehicle Engine
