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《涡轮增压汽油机数值模拟和性能优化的研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、摘要本文进行了1.5L汽油机涡轮增压匹配的研究,并对气道喷射增压汽油机进行了参数优化,对直喷增压汽油机部分负荷工况进行了分析研究。文中对1.5L气道喷射自然吸气发动机的工作过程进行了模拟,并在此基础上建立直喷模型,并对直喷汽油机和增加可变气门正时机构后的发动机进行了模拟计算与分析,结果表明改进后的直喷方案能提高发动机动力性,但对经济性改善作用不明显。以气道喷射发动机为原型,对其选配涡轮增压器,进行了匹配计算与试验分析;并对发动机的进排气正时,进气管尺寸进行了优化,最终确定了相关参数。结果表明增压后汽油机的动力性有大幅度提升,经济性有所改善,但排气温度有
2、所升高。以直喷发动机为原型,对其选配了涡轮增压器,进行了匹配计算与分析;并计算了不同节气门开度下,不同的进排气正时时发动机的BMEP(平均有效压力),BSFC(比油耗)等,优化了不同节气门开度和转速下的进排气正时。结果表明涡轮增压中冷直喷汽油机排气温度高,在部分负荷时,发动机运行线靠近喘振线,应重新选择匹配策略。本文对1.5L汽油机的模拟计算都是与相关试验结合的,计算结果与试验结果有较好的一致性,对汽油机的增压匹配与性能计算具有重要的指导意义。关键词:汽油机涡轮增压匹配气道多点喷射汽油机缸内直喷IABSTRACTInthispaper,amatchin
3、ganalysisof1.5Lgasolineenginewithturbochargerwasstudied,andtheparameteroptimizationofMPITCIVVT(multi-pointinjectturbocharginggasolineenginewithvariablevalvetiming)wascrarriedout,meanwhilethestudyofpartloadconditionintheGDITCIVVT(gasolinedirectinjectturbocharginggasolineenginewit
4、hvariablevalvetiming)gasolineenginewascompleted.Firstly,theworkingprocesssimulationof1.5LMPI(multi-pointinject)gasolineenginewasaccomplished.TheGDI(gasolinedirectinject)andGDIVVTmodelswerebuiltonthebasisofMPIsimulation,andthesimulatingcralculationandanalysisofbothGDIandGDIVVTmod
5、elswerefinished,theresultshowedthatthedynamicralperformanceoftheoptimizedmodelwasimproved,whilethefueleconomyremainedstill.Secondly,amatchinganalysisof1.5LMPIenginewithturbochargerwasdone,theinlet/exhaustvalvetimingandthedimensionsofinletpipewereoptimizedtodeterminetherelatedpar
6、ameters.Astheresultsindicrated,thedynamicralperformanceandfueleconomyoftheturbochargedmodelwerelargelyimproved,buttheexhausttemperatureincreased.Lastly,amatchinganalysisof1.5LGDIenginewhichwasmatchedwithturbochargerwascompleted,thevaluesofBMEPandBSFCwerecralculatedundervariousth
7、rottleopeningandinlet/exhaustvalvetiming,andtheinlet/exhaustvalvetimingofdifferentthrottleopeningandenginespeedwasoptimized.Asshowedfromtheresult,theexhausttemperaturewashigherthanexpectation,andtheworkinglinewasclosetothesurgelineunderpartloadcondition,thereforethematchingstrat
8、egyshouldbereselected.Thesimulationandanalysiso