二甲醚均质压燃发动机燃烧特性的研究_英文_

二甲醚均质压燃发动机燃烧特性的研究_英文_ L IU Sheng2hua , Eddy R Cuty Clemente , HU Tie2gang , L üSheng2chun , ZHU Chi ()Depa rt ment of A uto mo bile Engineering , Xi’a n J iao to ng U niver sit y , Xi’an 710049 , Chi na Abstract : A te st engine wa s mo dified f ro m a single cylinder die sel engine by lo wering it s co mp re ssio n ratio () to 10 . 7 . The ga seo us di met hyl et her DM Ei s int ro duced to t he inlet pipe wit h a co nsta nt temp erat ure a nd t he co mbustio n characteri stic s of t he HCCI engine were investigated. The exp erimental re sult s sho wed t hat t he HCCI engine co mbustio n demo nst rate s a t wo2stage heat relea se p rocess w hich occur s at 610 K a nd 900 K. A bo ut 10 % of to tal heat i s relea sed in t he fir st stage , w hile o ver 70 % of to tal heat relea se i s given by t he seco nd st age co ncent rated nea r TDC. Engine load o r mixt ure A/ F ratio ha s significa nt i nf l uence o n t he maximum cylinder p re ssure a nd it s occur ring po sitio n , t he p at ter n of t he p ressure ri se rate a nd t he heat re2 lea se rate w hile lit tle inf l uence o n t he se co mbustio n p ara meter s by engine speed. Key words : HCCI ; DM E ; Co mbustio n ; Heat relea se rate CLC number : T K421 Document code :A 二甲醚均质压燃发动机燃烧特性的研究 刘圣华 , Eddy ,胡铁刚 ,吕胜春 ,朱 驰 ()西安交通大学 汽车工程系 ,陕西 西安 710049 摘要 :二甲醚均质压燃发动机由一台单缸柴油机改造而成 ,其压缩比为 10 . 7 。二甲醚气体随进气进入气 缸 ,形成均质混合气 。通过试验采集分析缸内压力 ,结果表明二甲醚均质压燃燃烧是一个两阶段放热过 程 ,分别发生在 610 K 和 900 K 左右 。第一阶段放热量较少 ,约占 10 % ,正常情况下第二阶段集中在上止 点附近 ,释放出 70 %以上的燃料热量 。发动机负荷对最大缸压力及其出现位置 、压力升高率和放热率曲线 形状等都有重要影响 ,而发动机转速对它们的影响比较小 。 关键词 :均质压燃 ;二甲醚 ;燃烧 ;放热率 reduced si mult a neo u sl y. They a re re sult ed f ro m Introduction t he p re mi xe d co mbu stio n a nd t he diff u sio n co m2 b u stio n , re sp ectively . Wit h t he help of t hree2 Bo t h reduci ng e xha u st e mi ssio n s a nd i n2 λ way cat al ytic co nver t e r a nd clo sed loop co n2 crea si ng t he r mal efficie ncy a re of great i mpo r2 )( t rol , S I e ngi ne e mi ssio n s H C , CO a nd x N O t a nce fo r t he i nve sti gatio n of i nt er nal co mb u stio n ca n be co nt rolle d eff ectively , ho weve r it i s still e ngi ne . The die sel e ngi ne s a re at t ractive beca u se ha r d to meet f urt her st ri nge nt st a nda r d s beca u se of t he hi gh t her mal efficie ncy. U nfo rt u nat el y t hei r N O a nd PM e mi ssio n s a re diffic ult to beof t he co mb u stio n of stoic hio met ric mi xt ure . x 3 收稿日期 : 2004209206 ;修订日期 :2004211230 。 ( ) 基金项目 : 国家基础性研究重大项目 2001 CB209206。 ( ) 作者简介 : 刘圣华 1964 - ,男 ,博士 ,教授 ,主要研究方向为内燃机燃烧及清洁替代燃料 。 Ba sed o n t he a nal ysi s of t he mecha ni sm s of b u stio n . So , t he pi sto n top la nd i s p a r tiall y cut t her mal N O a nd PM , it’ s bet t er to co mp let e e n2 acco r di ng to t he de si gned co mp re ssio n ratio . The gi ne co mb u stio n p roce ss u nde r lo w t e mp e rat ure co mp re ssio n ratio i s set to be 11 acco r di ng to t he wit h ho mo ge neo u s cha r ge . Therefo re , ho mo ge2 a r ra nge me nt of t he st udy , a nd act uall y , it i s ( ) 10 . 7 . The rat ed e ngi ne sp ee d i s 2 300 r/ mi n . neo u s c ha r ge co mp re ssio n i gnitio n H CC Ico m2 Fo r t he e ngi ne wo r ki ng u nde r t he H CC I op e rat2 bu stio n p roce ss i s i nve sti gat e d i n rece nt yea r s ac2 i ng co nditio n , it s rat ed po wer i s a bo ut 5 k W. co r di ngl y. Theo reticall y , t he co mbu stio n t a ke s p lace spo nt a neo u sl y t hro ugho ut t he lea n mi xt ure Fi g. 1 sho w s t he sc he matic dia gra m of t he under a lo w t e mp erat ure co nditio n . In t hi s ca se , t e st be nc h . The o ri gi nal die sel i njectio n syst e m t he fo r matio n of N O a nd PM will be supp re sse d x i s re mo ve d , i n st ea d , by reduci ng it s p re ssure , [ 2 ] DM E i s fi r st evapo rat ed , a nd t he n , it i s gui ded si mult a neo u sl y a nd si gnifica nt l y. H CCI e ngi ne ha s rece nt l y bee n st udie d i nto t he e ngi ne i nlet pip e . Therefo re , DM E i s co mp let el y p re mi xed wit h ai r p rio r to it s co m2 wo rl dwi de beca u se of it s hi ghe r efficie ncy a nd ul2 [ 3 - 8 ] N O a nd PM e mi ssio n. Ho wever , b u stio n . To ma ke t he f uel met e ri ng syst e m t ra lo w x wo r ki ng st a bl y , a c heck val ve a nd a t hro t t le p ro ble m s still need to be sol ved , suc h a s t he co n2 val ve a re set i n t he f uel delive r y li ne . The t hro t2 t rolli ng of i gnitio n ti me a nd co mb u stio n rat e o ve r t le val ve i s to co nt rol ga seo u s DM E f lo w rat e , by a wi de r ra nge of e ngi ne sp eed a nd loa d , t he re2 w hic h t he H CC I e ngi ne po wer i s co nt rolled . A n ductio n of H C a nd CO e mi ssio n s under lo w loa d elect ro nic bala nce i s u se d to wei gh t he f uel co n2 a nd so o n . H CC I co mbu stio n i s co nt rolle d by sump tio n , so t hat t he f uel eco no my ca n be st ud2 che micall y ki netic reactio n . Therefo re , t he ie d. The A/ F ratio of t he mi xt ure i s mea sured 2 wo r ki ng co nditio n s a nd f uel p rop er tie s ha ve si g a nd calc ulat ed f ro m e xha u st o xyge n co nce nt ra2 nifica nt eff ect s o n t he co mbu stio n p roce ss. Di m2 tio n . A heati ng syst e m i s app lie d to keep t he ( ) et hyl et her DM Eha s a hi gher cet a ne numbe r a nd i s o ne of t he be st f uel s fo r H CC I e n2 t e mp e rat ure of ga seo u s DM E co n st a nt i n ca se it [ 2 ,7 - 8 ] may va r y wit h t he c ha nge of ai r/ f uel ratio a nd gi ne, but t he co mbu stio n cha ract eri stic s of e ngi ne sp ee d , beca u se t he t e mp e rat ure of t he DM E H CCI co mbu stio n a re le ss st udied. mi xt ure ha s si gnifica nt eff ect o n H CC I co mbu s2 In t hi s p ap er , H CC I co mb u stio n c ha ract e r2 tio n . The cyli nde r p re ssure i s se n se d by Ki st le r i stic s a re i nve sti gat ed. Ba se d o n t he sa mp led cyl2 p re ssure se n so r . The dat a a re acque st e d a nd a na2 i nder p re ssure , t he co mbu stio n heat relea se rat e , cyli nder t e mp e rat ure , t wo st a ge i gnitio n c ha rac2 l yzed by u si ng A VL 619 syst e m. t eri stic s a re a nal yzed . The eff ect s of e ngi ne sp ee d a nd loa d o n e ngi ne co mbu stio n a re st ud2 ie d , too . 1 Experimental Procedures A si ngle2cyli nder , fo ur2st ro ke , nat urall y a s2 pi rat ed , di rect i njectio n die sel e ngi ne wa s ret ro2 1 - Elect ronic balance ; 2 - Fuel t ank ; 3 - Exit2valve ; 4 - Heat er ; fit t ed to be H CC I t e st e ngi ne . The bo re a nd 5 - Flow rate cont rol valve ; 6 - Enco der ; 7 - Pre ssure senso r ; st ro ke a re 100 mm a nd 115 mm , a nd t herefo re 8 - HCCI engi ne ; 9 - Dyna mo met er ; 10 - Tacho met er ; 3 t he to t al di sp lace me nt i s 903 cm. The o ri gi nal 11 - Exha u st t e mp erat ure senso r ; 12 - Emi ssio ns anal yzer ; 13 - Co mbu stio n a nal yzer ωco mb u stio n cha mbe r i s a deep“”t yp e bo wl2i n2 Fig. 1 Schematic diagram of the test bench pi sto n , so t hat t he i nlet swi rl ca n be e nha nce d to Tab. 1 Comparisons of f uel properties Fuel p rop ertie s DM E Met ha nol Ga soli ne Die sel Cet a ne nu mber 5 < 15 55,60 40,55 235 450 370 250 Ignitio n t e mp erat ure / ? ( )Lo w heat val ue / MJ / kg 27 . 6 19 . 5 48 . 5 42 . 5 Sat urat ed p re ssure / M Pa ( )0 . 51 20 ? — — — Boili ng poi nt / ? 30,225 180,360 - 24 . 9 65 ( )L at ent heat / kJ / kg 310,320 410 1 110 290 2 ) A nd t here still e xi st s a p re ssure diff erapo rat e . 1DM E ha s a hi gh cet a ne numbe r a nd lo w i gnitio n t e mp erat ure , w hich i s app rop riat e fo r e nce bet wee n DM E vapo r a nd a mbie nt ai r . So , co mp re ssio n i gnitio n . Exp eri me nt s i ndicat e t hat t he re i s no nee d to i n st all a uxilia r y sy st e ms to DM E ca n wo r k t he e ngi ne unde r t he co mp re ssio n heat t he ai r , to heat t he f uel o r to p u mp DM E ratio ra nge f ro m 8 to 18 o r eve n wi de r ; vapo r , w hic h ma ke s t he f uel deliver y syst e m ) 2It i s ha r d to p rep a re ho mo ge no u s c ha r ge quit e si mp le . fo r ga soli ne , die sel a nd met ha nol fo r t hei r hi ghe r 2 HCCI Engine Combustion Characteristics evapo rati ng t e mp erat ure o r lat e nt heat . The boili ng poi nt of DM E i s - 24 . 9 ?a nd t he lat e nt 2 . 1 Eff ects of a ir/ f uel rat io ( engine loa d) 21 heat i s 410 kJ ?kg. The lo w evapo rati ng t e m2 p e Fi g. 2a a nd Fi g . 2 b co mp a re t he mea sured rat ure a nd lat e nt heat ma ke t he mi xt ure p rep a2 cyli nde r p re ssure s unde r diff ere nt e ngi ne lo a d at ratio n ea sy fo r H CC I e ngi ne ; t he co n st a nt sp ee d of 1 800 r/ mi n a nd 2 000 ) 3B y re duci ng t he p re ssure , DM E will ev 2 r/ mi n re sp ectivel y. Fig. 2 Measured cyl inder pressures p re ssure ri se , t he re i s a small a nd ge nt le ri se . cyli nde r p re ssure s co r re spo ndi ngl y . The shap e of t he heat relea se rat e i ndicat e s t hat DM E H CC I d p ( )2 give s mo re deThe rat e of p re ssure ri se φd co mbu stio n p roce ss i s a t wo2st a ge t yp e . t ailed i nfo r matio n a bo ut t he c ha nge of t he cyli n2 Fig. 3 Rates of cyl inder pressure rise Fig. 4 Rates of heat release Fi r st l y , wit h t he i ncrea se of e ngi ne lo a d , i . d p .H CC I e ngi ne beco me s noi sie r fo r t he hi gher φd e . wit h ric her DM E/ ai r mi xt ure , t he ma xi mu m The co mp re ssio n i gnitio n i s a che micall y co n2 p re ssure beco me s hi gher ; t he cra nk a ngle at t rolle d p roce ss. H CC I co mbu stio n occur s spo n2 w hich t he ma xi mum p re ssure occur s mo ve s fo r2 t a neo u sl y t hro ugho ut t he c ha mbe r a nd nea r wa r d. So do t he p re ssure ri si ng rat e s. Al so , t he ma xi mum p re ssure s a re 3 . 6 M Pa a nd 4 . 5 M Pa p roce ss i s che micall y co nt rolle d , a nd t h u s le ss occur ri ng at t he cra nk a ngle of 8?CA B TDC a nd aff ect ed by t he e ngi ne sp ee d. The sli ght diff er2 φ 4?CA B TDC ; t he ma xi mum d p/ da re 0 . 22e nce s re sult s f ro m t he lit t le cha nge i n mi xt ure M Pa/ ?CA a nd 0 . 5 M Pa/ C?A occur ri ng at 1C?A A t e mp e rat ure due to t he diff ere nt e ngi ne sp ee d. TDC a nd - 1?CA A TDC , re sp ectivel y. If t he e ngi ne loa d i s i ncrea sed to be p= 0 . 32 M Pa , BM EP k nocki ng i s i nevit a ble . The f l uct uatio n of t he cyli nder p re ssure sho w s t he k nocki ng c ha ract e r2 i stic s of co mp re ssio n i gnitio n e ngi ne s. Seco ndl y , t he DM E H CC I co mb u stio n p roce sse s p ro ve to be t wo2st a ge st yle . In Fi g. 4 , co mp a red wit h t he seco nda r y st a ge co mbu stio n , t he heat relea sed i n t he fi r st st a ge t a ke s a small p a rt of t he to t al co mb u stio n heat . U nde r p=BM EP 0 . 25 M Pa at 1 800 r/ mi n op erati ng co nditio n , t he to t al heat relea se d i n t he fi r st st a ge i s a bo ut 13 p erce nt . Wit hi n 15?CA of t he seco nd st a ge co mb u stio n , a bo ut 75 p erce nt of t he f uel i s co n2 su me d . The mai n co mbu stio n happ e ne d i n a ver y Fig. 5 Comparison of heat release rates at ( ) sho r t cra n k a ngle ti me re sult s i n hi ghe r t he r2 p= 0 . 25 MPaBMEP mal efficie ncy. A s sho we d i n Fi g. 3 to Fi g . 4 , al mo st all t he 2 . 3 Compression ign it ion temperature analysis fi r st st a ge co mbu stio n st a r t s a bo ut at 17?CA B TDC a nd e nds at a bo ut 10?CA B TDC. It see m s Fi g. 6 sho w s t he calculat e d t e mp erat ure of t hat t he fi r st st a ge i s le ss aff ect ed by t he ai r f uel t he cyli nder ga se s. If t he k nocki ng co mbu stio n i s ratio f ro m t he cur ve s of t he rat e s of heat relea se p ut a si de , t he fi r st st a ge co mbu stio n occur s a2 a nd t he rat e s of cyli nde r p re ssure ri se , ho wever , ro u nd t he t e mp erat ure of 610 K , t he seco nd oc2 t he seco nd st a ge i s si gnifica nt i nf l ue nce d. Be2 c ur s at a bo ut 900 K , w hich i s u nrelat ed to t he t wee n t he t wo st a ge s , it i s so2calle d col d f la me e ngi ne sp eed a nd loa d , ho weve r , t he p ea k t e m2 p e rio d. The active p a r ticle s numbe r ma y va r y p erat ure of H CC I e ngi ne co mb u stio n i s lo we r wit h t he ai r/ f uel ratio , w hic h c ha nge s t he chai n t ha n 1 700 K. Eve n under k nocki ng co mbu stio n reactio n great l y . In Fi g. 4a , t he seco nd st a ge co nditio n , t he hi ghe st avera ge t e mp erat ure i s heat relea se st a r t s at diff e re nt cra nk a ngle s still belo w 2 000 K. Ge nerally , beca u se H CC I 1?CA , 3?CA , 5?CA B TDC wit h t he i ncrea se d e ngi ne bur n s ho mo ge neo u s a nd much lea ne r e ngi ne loa d , re sp ectivel y. The lit t le cha nge i n c ha r ge , t he t e mp erat ure t h ro ugho ut t he cyli nde r A/ F ratio re sult s i n great c ha nge of t he seco nd i s t here by muc h lo wer a nd mo re unifo r m t ha n co mb u stio n st a ge . The ma xi mu m heat relea se t he t ra ditio nal SI e ngi ne o r C I e ngi ne . Acco r di ng rat e cha nge s great l y , too . to t he t her mal N O mec ha ni sm , t he lo we r t e m2 2 . 2 Eff ects of engine speed p erat ure i s ha r d to ge nerat e p a rticle s li ke N , O Fi g. 5 co mp a re s t he heat relea se rat e unde r a nd O H to fo r m N O a nd N O, t hat’s w hy H CC I2 t he sa me e ngi ne of 0 . 25 M Pa at 1 800 pBM EP e ngi ne e mit s al mo st zero N O .x r/ mi n a nd 2 000 r/ mi n . The total co mbustio n du2 Fig. 6 Temperature of the cyl inder gases [ 2 ] Zhu Chi , L iu Shenghua . Experimental Investigatio n 3 Concl usions of DM E HCCI Engi ne Emi ssio ns [ J ] . Tra nsactio ns () of CSIC E , 2004 , 22 1:51 - 55 . ()1 The co mb u stio n of DM E H CC I e ngi ne Hi sa kazu Suzuki , No riyuki Koike , Mat suo Oda ka . [ 3 ] i s cha ract erized wit h t wo2st a ge heat relea se o bvi2 Co mbustio n Co nt rol Met ho d of Ho mo geno us Char ge o u sl y . The fi r st st a ge occ ur s at 610 K a nd t he Diesel Engines [ C ] . SA E Pap er 980509 ,1998 . seco nd i s o ve r 900 K. A bo ut 10 % heat i s re2 Shigeyuki Ta naka , Fer ran A yala , J a mes C Keck , et [ 4 ] lea sed i n t he fi r st st a ge , while t he seco nd gives o ut al . Two2Stage Ignitio n in HCCI Co mbustio n and more t han 70 % near TDC under normal operating HCCI Co nt rol by Fuel s a nd A dditives [J ] . Co mbus2 co nditio ns , and t he later o ne takes more important () tio n a nd Flame , 2003 , 132 2:219 - 239 . To ma s W Rya n , Timo t hy J Calla han. Ho mo geno us [ 5 ] role in DM E HCCI engine performance. Cha r ge Co mp re ssio n Ignitio n of Die sel Fuel [ C ] . ()2 The co mbustio n duratio n decreases wit h SA E Pap er 961160 ,1996 . t he i ncrea se of e ngi ne loa d . Engi ne sp eed ha s Chen Zhili , Mit suru Konno , Shinichi Goto . St udy o n [ 6 ] le ss eff ect o n it s co mbu stio n cha ract eri stic s. Ho mogeno us Premixed Charge CI Engine Fueled wit h ()The p ea k cyli nde r p re ssure a nd t e m2 3 () L P G[J ] . J SA E Review , 2001 , 22 2:265 - 270 . p e rat ure i s lo wer u nde r H CC I op e rati ng mo de . L i u Shenghua . Exp erimental St udy of DM E HCCI [ 7 ] The co mb u stio n i s smo kele ss a nd give s off al2 Engine Op erating Cha racteri stic s [ C ] . Proceedi ngs mo st zero N O e mi ssio n .x of t he Inter natio nal Sympo sium o n Clea n and High2 ( ) Efficiency Co mbustio n in Engine s A , Tianjin , Ref erences : 2002 . [ 1 ] Zho u Lo ngbao . Principle of Inter nal Co mbustio n Hyunguk Kim , Sungwoo Cho , Kyo ungdo ug Min. [ 8 ] Engine [ M ] . Beijing : China Machine Press , 1998 , Reduced Chemical Kinetic Mo del of DM E fo r HCCI 27 - 36 ,192 - 216 . Co mbustio n [ C ] . SA E Pap er 200320121822 ,2003 . file:///D|/新建 Microsoft Word 文档.txt df机及ov及ojxlkvjlkxcmvkmxclkjlk;jsdfljklem,.xmv/.,mzxlkjvolfdjiojvkldf file:///D|/新建 Microsoft Word 文档.txt2012/8/2 16:09:56