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《負(fù)荷、 預(yù)噴與主噴時(shí)刻對(duì)柴油機(jī)富氧燃燒的影響.pdf》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫(kù)。
1、第34卷第12期公路交通科技Vol.34No.122017年12月JournalofHighwayandTransportationResearchandDevelopmentDec.2017doi:10.3969/j.issn.1002-0268.2017.12.018負(fù)荷、預(yù)噴與主噴時(shí)刻對(duì)柴油機(jī)富氧燃燒的影響1221姚佳巖,劉浩業(yè),肖建華,付百學(xué)(1.黑龍江工程學(xué)院,黑龍江哈爾濱150050;2.清華大學(xué)汽車安全與節(jié)能國(guó)家重點(diǎn)實(shí)驗(yàn)室,北京100084)摘要:柴油機(jī)熱效率高,動(dòng)力性能優(yōu)越,廣泛應(yīng)用于汽車和工程機(jī)械中。但由于柴油機(jī)擴(kuò)散燃燒的特點(diǎn),容易在燃燒室的局部形成過(guò)濃區(qū)域,使其碳煙排放一般
2、較高。針對(duì)柴油機(jī)碳煙排放的問(wèn)題,通過(guò)改變進(jìn)氣中氧氣的體積分?jǐn)?shù),實(shí)現(xiàn)了柴油機(jī)富氧燃燒。在氧氣體積分?jǐn)?shù)分別為21%,23%,25%,27%,29%的條件下,試驗(yàn)研究了在不同的負(fù)荷、不同主噴時(shí)刻和預(yù)噴時(shí)刻下柴油發(fā)動(dòng)機(jī)燃燒和排放特性。研究結(jié)果表明:在所研究的負(fù)荷范圍和主噴、預(yù)噴時(shí)刻條件下,隨著進(jìn)氣氧濃度提高,預(yù)噴放熱提前,放熱峰值提高;主噴放熱略有提前,放熱峰值基本不變;NO排x放顯著增加,且指示熱效率提高;在小負(fù)荷工況下,隨著進(jìn)氣氧濃度的增加,燃燒持續(xù)期基本不變,排氣煙度變化不大,但燃燒效率明顯改善;在大負(fù)荷工況下,隨著進(jìn)氣氧濃度的增加,燃燒持續(xù)期明顯縮短,燃燒效率變化不大,排氣煙度在進(jìn)氣氧濃度達(dá)到
3、25%之前,隨著進(jìn)氣氧濃度的提高而明顯降低,進(jìn)一步增加進(jìn)氣氧濃度對(duì)排氣煙度的影響不再顯著;隨著主噴時(shí)刻的提前,排氣煙度降低,NO排放略有升高,熱效率增加;預(yù)噴時(shí)刻變化對(duì)發(fā)動(dòng)機(jī)燃燒x排放特性的影響較小。關(guān)鍵詞:汽車工程;柴油發(fā)動(dòng)機(jī);噴射策略;富氧燃燒;燃燒特性;排放特性+中圖分類號(hào):TK421.2,U464.172文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1002-0268(2017)12-0123-08EffectofDifferentLoads,PilotInjectionandMainInjectionTimingsonOxygen-enrichedCombustioninDieselEngine1221Y
4、AOJia-yan,LIUHao-ye,XIAOJian-hua,FUBai-xue(1.HeilongjiangInstituteofTechnology,HaerbinHeilongjiang150050,China;2.StateKeyLaboratoryofAutomotiveSafetyandEnergy,TsinghuaUniversity,Beijing100084,China)Abstract:Dieselengineshavehighheatefficiencyandpowerperformance,whicharewidelyappliedinautomobilesande
5、ngineeringmachinery.However,duetothediffusioncombustionofdieselengines,therearefuel-richregionsinthecombustionchamberduringcombustionwhichleadstohighersootemissions.Tosolvesootemissionsindieselengines,weachievedoxygen-enrichedcombustioninadieselenginebycontrollingthedifferentintakeoxygenvolumefracti
6、on.Thetestresearchonthecharacteristicsofcombustionandemissionofthedieselengineisconductedatvariousengineloads,pilotinjectiontimingsandmaininjectiontimingswiththeoxygenvolumefractionat21%,23%,25%,27%and29%.Theresearchresultshowsthat(1)underthestudiedloadrange,pilotinjectiontimingandmaininjectiontimin
7、gconditions,withtheincrementofintakeoxygenconcentration,pilotinjectionheatreleaseadvanced,andthepeakheatreleaseincreased;(2)themaininjectionheatreleasealsoadvancedalittlewithoutsignificantpeakchange;(