涡流-滚流拓宽汽油机稀燃极限的试验  

Experiment of Gasoline Engine on Extending Diluted Combustion Limit with Swirl-Tumble Flow

作　　者：李浩冉 孙凯[1] 李磊[1] 张志进 王天友[1] Li Haoran;Sun Kai;Li Lei;Zhang Zhijin;Wang Tianyou(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;China North Engine Research Institute,Tianjin 300400,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]中国北方发动机研究所,天津300400

出　　处：《内燃机学报》2021年第5期402-408,共7页Transactions of Csice

基　　金：国家杰出青年科学基金资助项目(51525603)。

摘　　要：基于一台4气门直喷汽油机,在部分负荷工况下对比研究了低滚流、高滚流以及涡流-滚流结合(简称涡流-滚流)3种不同的进气形式在废气和进气两种稀释氛围中对燃烧和排放的影响.结果表明:在进气稀释条件下,与稀燃极限λ为1.37的低滚流原机相比,高滚流可将λ拓宽至1.44、燃油消耗率(BSFC)降低10%,涡流-滚流可拓宽极限λ至1.51、BSFC降低12%;在废气稀释条件下,与稀燃极限废气再循环(EGR)率为23%的低滚流原机相比,高滚流可拓宽极限EGR率至27%、BSFC降低5%,涡流-滚流可拓宽极限EGR率至28%以上、BSFC降低8%.排放方面,与原机低滚流无稀释工况相比,高滚流结合稀释燃烧最多分别使NO_x降低69%、CO降低89%和HC升高74%;涡流-滚流结合稀释燃烧最多分别使NO_x降低63%、CO降低87%和HC升高44%.The effects of pure tumble flow and swirl-tumble flow on combustion,diluted combustion limit,fuel economy and emissions were studied on a four-valve gasoline direct injection engine at part load under air dilution condition and exhaust gas dilution condition,respectively.The results show that under air dilution condition,compared to the original engine with a weak tumble flow andλlimit of 1.37,the high tumble flow can extend theλlimit to 1.44 and reduce the brake specific fuel consumption(BSFC)by 10%.The combination of swirl and tumble flow(swirl-tumble flow)can further extend theλlimit to 1.51 and reduce the BSFC by 12%.Under exhaust gas dilution condition,compared to the original engine with a weak tumble flow and EGR limit of 23%,the high tumble flow can extend the EGR limit to 27%and reduce the BSFC by 5%.The swirl-tumble flow can extend the EGR limit to more than 28%and reduce the BSFC by 8%.Compared to the original engine with weak tumble flow,the combination of high tumble flow and diluted combustion can reduce NOx and CO emissions by up to 69%and 89%respectively and increase the HC emissions by up to 74%.While the swirl-tumble flow and diluted combustion can reduce NOx and CO emissions by up to 63%and 87%,and increase the HC emissions by up to 44%.

关 键 词：汽油机 涡流-滚流结合进气 稀释燃烧 燃烧特性 燃油经济性 

分 类 号：TK417[动力工程及工程热物理—动力机械及工程]