Mô phỏng quá trình đánh lửa trong buồng cháy động cơ dual fuel biogas diesel

T^P CHi KHOA HQC & C6NG miU{: (Ac TRUING D^I HQC K* THII^T * S6 86 - 2012 MO PHONG QUA TRINH DANH LUA TRONG BUONG CHAV DONG CO DUAL FUEL BIOGAS-DIESEL SIMULATION OF IGNITION PROCESS IN THE COMBUSTION CHAMBER OF BIOGAS-DIESEL DUAL FUEL ENGINES Bid Vdn Ga, Trdn Vdn Nam, Le Minh Tien, Nguyen Viit Hdi Dgi hgc Dd Ndng Nhan bdi ngdy 21 thang ndm 2011 TOM TAT Anh hu&ng cua thinh phin nhiin liiu biogas cdc diiu ki$n cua hdn hqrp trux&c chdy cun nhw cic diiu kiin cua nggn ICfa mdi din diin biin qui trinh ddnh lira budng chdy chdm cau ding CO dual fuel biogas-diesel duxyc md phdng nh& phin mim ding hgc thuy FLUENT Kit q cho thiy tdng li/r^mg nhiin liiu phun mdi, rOt ngin th&i gian phun, ting gdc phun s&m hay tdng nh di hdn hop tru&c ddnh lOa giup rut ngin th&i gian ddnh iCra doi v&i nhiin liiu biogas ngh^ Nguxyc l^i, tdng luxyng xi hii luu hay gidm ti s6 nin cua ding co dual fuel biogas-diesel du{ (90 tCr dgng co dlesel Id giii phdp di ddm bdo cho ding co Idm viic v&i nhiin liiu biogas giiu'^ khdng xiy kich nd ABSTRACT Influences of biogas fuel components, conditions of unburned mixture as well as conditkms pilot flame on the progress of ignition processes in the spherical combustion chamber of biogas-die dual fuel engines are simulated by the gas dynamics software FLUENT The results show tfia( increasing the amount of fuel in pilot flame, shortening injection duration, increasing the advance ignition angle or increasing the temperature of the mixture before ignition will shorten the ignition for poor biogas fuel Conversely, increasing the amount of exhaust gas recirculation or reducing compression ratio of biogas-diesel dual fuel engines converted from the diesel engine is a measur ensure that the engine runs onrichbiogas without knock L GIOI THIEU Chat Ihdi hiiu co qua trinh san xudt nong nghiep, chdn nudi, che bign ndng lam sdn d nude ta rat cd gid trj sdn xudt biogas Theo udc tinh tigm ndng biogas ciia nude ta cd thg dat dugc ty mVndm [3] Theo cdc cong trinh nghign cim d3 dugc cong bo, lm* biogas cd thg sdn xuat dugc IkWh dien, tiet kiem dugc 0,4 lit dau diesel va gdp phdn lam gidm phdt thai 1kg CO: vao bdu quygn bang may phdt dien chay bang biogas [5], [6] Ngu ap dyng cdng nghe dg phdt dien, mdi ndm nude ta cd the san xudt dugc ly kWh dien bang biogas, tucmg duong vdi 10% tdng ndng luang dien san xuat hien nay, giam phat thai tri?u tdn CO: (tuong duong 1,5 trieu ldn C) vao bau quyen Neu so vdi miic phdt thdi C tuong duang cua nude ta hien Id 24 trieu tdn/nam thi mirc giam dat dugc 6,5% Tuy nhien nguon sdn xuat biogas khong tap trung ngn dg tan dyng hgt tiem nang biogas cd sdn cho sdn xudt dien ndng chiing ta can phdt trien cdng nghe phii hgp de cd thg sir dyng biogas iren cdc chung loai va kich c9 dgng ca khdc Trong nhimg cong trinh trudc day chiing tdi dd cong bo cong nghe chuyen ddi dpng co diesel sang dpng ca dual fuel biogas-diesel vdi bg phy kien GATEC Cdng nghe ndy cho phep dgng ca cd thg ch^y bdng nhien lieu, hodc biogas, hodc diesel, phii hgp vdi nhu cdu su dyng thuc tg Trong qua trinh phdt irien cong nghe chung loi thay cd nhung van dg can dugc nghien ciu tudng tan vg mdt ly thuyet nhu anh hudng ciia thdnh phan nhign lieu biogas, cac dieu kign ddnh lira ciia tia phun moi, kgt cdu ciia dpng CO dgn qua trinh danh lira vd qud trinh chay CLia dpng CO dual fuel biogas-diesel Nghign ciru qud trinh chay dual fuel cua nhign lieu cd dp linh khigl cao da dugc nhieu nhd khoa hgc cdng bo Mohamed va dong su [1] nghign ciru gidi han chdy kich no ciia dpng ca dual fuel su dyng cdc logi nhien lieu LPG, CNG vd methane Kgl qud cho thdy methane cd tinh chdng kich no cao nhdt va hi?u sudi '•""1 ^" ''^" "1^^* '""" rv-,-f« D-j-v", >.i TAP CHi KHOA HQC & C6NG NGHf CAC TRlTO'NG DAI HQC KY THUi^iT * S6 86 - 2012 dong sy [2] da thiet lap md hinh vat ly dg nghien ciiu tinh chdt cua ddng chay va ciia qua trinh chdy cua hdn hop LPG vd xang Kgt qua cho thdy vi tri phun nhign lieu long dnh hudng dang kg dgn su phdn bd nhiet dp vd toe dp buong chdy Trong cong trinh ndy chiing toi se nghien ciiu dnh hudng cua cdc ygu td khdc dgn qud trinh danh liia va chdy ciia hon hgp biogas thyc te va khdng bang phdn mem FLUENT LY THUYET VE MO HINH DANH LUA VA CHAY Qud trinh ddnh lira ciia hon hgp dugc md phdng bdng phuang trinh van chuygn ddi voi cac phan tit tu chdy Y,^, cho bdi phuong trinh sau [3]: -^+v.(pvr )=v -^v)dt ''^ •' [Sc -pS„ (1) " Trong dd Y.g Id ndng dp khdi lugng cua phdn tur thu dgng dac tnmg cho nhiing goc hoa hpc dugc hinh thdnh tir phdn ling cua nhien lieu va khdng viing danh lira; Sci Id chuan sd Schmidt roi, |i, la nhdt roi; v Id tdc dp ddng chay; S.E Id dai lugng nguon ddi vdi nhiing phdn tii tu chdy dugc bieu diln bdi bieu thlic: ^^'If- (2) Trong dd to Id thdi diem nhign lieu dugc cung cdp vao viing danh lira, T,g la thdi gian chay trg Cd mo hinh ddnh lira vd then ky chay tri dugc xii ly mot cdch tuong tu FLUENT vdi cdc dai lugng ngudn khac Bieu thirc tdng quat doi vai r,^ dupe thiet lap dua trgn moi quan he Arrhenius [3]: A\ p T n

!•( Hi K\U)\ \HH X< ()N< N(.llt ( \< I »l \ < n \ l Hli:iiiii livii dmh hiiuii- ^^^^ I Imh \.hnn^ \cu 11 s."> iKi! cua J o n - co- la IS thi iliO uch \ i lanh cua >ionLi ci> la V,, 1.7.1(1 'm' dia • ir iic su nap cua III'MIL: CO' i] ihi IUOITJ khoivj cue dai nap vao dimy co' la m, : i d 'ky LuiTTT^ [inicn iicii dicscI loi da co llic iiluiii \.ui dom: CO- kh: chav Jav lai la in, 0.15 H) 'k- N.uii! kronu 1\ ilui\cl nhicn hen diesel niani: vao buonL; cha\ iroiiL: iiiol chu Irinh cha\' * SOS(>-ZI)12 l;i\ i;n l;i '.' ''- 'I-I i 'f ''''' i^himg i;i CO the linh ilii'dv n:liiL' liiiMi!' pliiiii Mini ung vol cac li |^ plinii kh;iL' nil.Ill M)IIL! qiii'i trinh danh lira va ji;iv LIHIIIL" III L'Ki liiiih liic ticli buong chay kiu,ii;' i|i;i\ iU.in;> llini L.M;III phun iiliiui lieu \.^ niinu 1, ihiiili liKi ii;"iii.u ni'iiiii lin/ng iiliiOii lieu IIK-'A'I III;IIIV van liuoivj ulidy Irony yia' tJoan pluinniui • ihav kha niing sir duny nicUianc dong co co ti so nin cao hon d o n g CO sir duny LPG, Thanh ph.in methane trdny biogas cung anh h u o n g den dang d u d n g c o n g eha\ cua hon hop Hinh gio thieu ket qua tinh loan dudng c o n g chay img vdi ham l u g n g CO^ biogas khiic Ket qua cho thdy hdm lugng CO: biogas cang Idn thi ihoi diem bat dau eha> nhanh ciia hdn h g p ciiny hi cham tre so vai thiri diem danh lira N h u vay de dcng co TAP CHi KHOA HQC & CONG NGHE CAC TRirtfNG D-M HQC KV THU^T * S6'86 - 20)2 , dual fuel hoat ddng binh thudng doi vai nhign lieu biogas ngheo chiing ta phdi tang gdc phun sdm Ndng lugng ngpn liia mdi dnh hudng rat ldn dgn duang cong chay (hinh 5) Khi ndng lugng phun moi ldn ban 10% nang lugng phun cue dai, thdi digm bdt ddu chay nhanh cua hon hgp biogas-khong it thay doi Nhung nang lugng phun mdi thdp hon gid tri ndy, thoi digm nhiet tdng nhanh thay doi rat m^nh theo ndng lugng phun Khi nang lugng phun thay ddi tir 250J xuong 200J, thdi digm bdt ddu chdy nhanh tdng tir 2,5ms Ign 7ms Ket qud ndy gidi thich vi dpng co dual fuel thgc lg 3500 ho?i dpng khorig dn dinh khi> ndng lugng phun mdi nhd hgn 10% ndng lugng c^rc dai Hinh gidi thi?u dudng' cong ddnh lua ciia hdn hgp biogas khong vdi thdi gian phun nhien li?u mdi thay doi tir 0,lms dgn 10ms Biogas chiia 70% methane vd 30% carbonic theo khdi lugng Kgt qua cho thdy thoi gian phun moi, nhiet dp trung binh ciia moi chdt budng chdy ldng gdn nhu tuyen tinh Sau giai doan nhift dp chdy tang nhanh Thdi digm bdt ddu chay nhanh tSng ty le vdi thai gian phun mdi Tdc dg tang nhiet dp trung binh buong chay khong bi anh hudng bdi thoi gian phun 3sao Hinh 3: Anh hu&ng cua nhien lieu den dgng du&ng Hinh 4- Anh hu&ng ciia phdn biogas den dgng duong cong chdy cua hdn hap cong chdy (T,=800K,Pi=l4bar,t,g=lms,Eig=500J) (T,=800,P,=10, t,s=lms, E,^=230J) Hinh Anh hu&ng ndng lining ddnh lira den dgng du&ng cong chdy cua hdn hap biogas-khdng (Ti=850K,P,=l4bar, t,g=Ims, biogas chua 70% methane, 30% carbonic theo khdi luang) Hinh 6: Anh hudng th&i gian ddnh lira den dang du&ng cong chdy ciia hdn hop biogaskhong (Ti=850K,P,=I4bar, E,f,=230J biogas chua 70% methane, 30% carbonic theo khdi hcang) TAP CHi KHOA HQC & C N G NGn(: CAC TKll^NG D^I HQC KY THUAT * 86-2012 T|n,r850K T,™,=B30K Hinh 7: Anh hu&ng nhii^t dg tru&c ddnh lua dSi dgng du&ng cong chdy ciia hdn lu.rp biogas-khdng (Biogas chua 70% melhane 30% carbonic theo khdi luong P, = lIbar.t.g=Ims.E,^=230J) Nhiet dp hon hgp truac danh lira cao giiip hon hgp dat nhiet dp lu chay sdm hon Hinh cho thdy nhiet trudc ddnh lira tang tu 820K Ign 900K, thdi digm bdt ddu chdy 2200 nhanh ciia hon hgp biogas-khon^ gidm di khodng 2ms Ket qua ndy cho thay chuyfin dpng ca diesel sang dpng co dual fuel biogasdiesel, chiing ta can giam ti s6 nen dpng co xuong mirc toi thigu dg trdnh kich no dpng ca ldm vi?c vdi bidgas c6 phdn methane cao Ap sudt cua hon hgp trudc chdy anh hudng rat manh den duang cong chdy ciing nhir den s^ gia tdng dp sual budng chay ddng tich (hinh 8a) T6c dp phdn irng (kg/s) phu thu^c vdo nhiet dp Khi dp suat irong buong chdy ldng cao, mat dp ciia hdn hgp tdng, neu nhipt dp trudc chay khong thzy doi thi thoi gian phan img dien hodn loan ddi vdi mpt the tich hon hgp cho truac gia tang Digu giai thich sv keo dai thdi digm bdt dau chay nhanh ap suat trudc chdy ciia hdn hgp tdng Dudng cong bien thign dp sudt buong chdy dang lich dugc tinh iheo phuong trinh trang thdi ciia ly tudng, cd dang tuong lit dudng cong bign thign nhiei dp (hinh 8b) „ Hinh 8: Anh hu&ng dp sudt tru&c ddnh lira den dang du&ng cong chdy (a) vd dp sudt tron^ buong chdy (b) cua hdn h(yp biogas-khdng (Biogas chira 70% methane 30% carbonic theo khoi luong Ti^850K.t,g=lms,E,g=200J) KIEM CHlTNG BANG THVC NGHIEM Kei qud tinh todn tren ddy dupe kigm chirng bang thuc nghiem trgn dpng co diesel dugc cdi tao thdnh dpng co dual fuel biogasdiesel: dpng CO D16 lap bp phu kien GATEC20 (hinh 9), dpng ca D24 lap bp phu kien GATEC20 va bo hdi luu thdi (hinh 10) Ddng CO ho^t ddng binh thudng khdng co tieng_g6 mdy buong chdy Kgt qua ihii nghiem nhu sau : D6i vdi biogas chita.dudi 80% phdn thg tich methane, Ichi phun moi nhien lieu diesel dudi 20% lugng phun cue da^ dpng CO boat dgng binh thudng Khi tang lugng phurt mdi tren gidi han nay, ddng cci T ^ P CHi KHOA HQC & CONG NGHE cAC TRUONG DAI HQC KY HU^T >!• S 86 - 2012 bat ddn phat tieng go mdv hrgnfr phun iiidi cang lany, [leiig go cang danh, Dieu phii h o p vdi ket qua Unh loan o hinli 5, Khi nang luotig diinh Ida cang Ion (hi ihoi gian chay cany rui ngan khien (nc gia tang ap siuu cany cao gav deny yd may, CO deu ph^i tieng ^f\ mdy ngav lugng plum nidi d.ii yia In lm ihidu (khoang \ir< liruiiy plum cue dai) Iteng gd may cliaiu liui chuny la d m hdi kru nidi lu\mg klii Ihai vua ph ii van diroii-j nap kC-l qua nav hinh 4- Ihoiyian lu chay cany dai liain huniy t o lion- hio-aseauLZ ldn Ddi \ d i nhicn lieu biogas co ihanh ph;'ui the lich methane Ion hon S()"o ca hai dduL: Hinh D(m'^ a> dual fuel hio^zus-diescl vw hn phu kien G.iTEC khang en he !hau\i hai lim iluii /ji>,i, /i, [jo„u ca dual luc! hiogas-tlicscl vo plnj kien C.ATEC \a he ihan-.^ hdi hni ihai [)c iranh hien lutmy go may dong eo dual fuel hiin viec \ o i nhien lieu biogas eo ihiinh phiin methane cao vdi niing hiong phun mdi vii thdi gian phun mdi da yiain [dl ihieu cliiing ta can lam ban hdn, hop hanLz each hdi luu nidi luong thai phu hup" h K E T L l AN Kei qua nyhien cuu Iren day cho phep chung la i-iii nluing kcl luan sau • I I r o n g cung dieu kien danh lua nhu nhien lieu biogas cang nglieo methane, ihdi gian tu chay cang keo dai Vice rut ny:ni didi gian tir chay cd the thuc hien biing each tany lugng nhien lieu phun mdi, rui ngan thai gian phun tiing goc plum soir, hay lang nhicl hon hop iru-dc phun T , \ l LIE! cai l:u) doni: cir diesel sansj dong eiv liiiid tuel hiogas-diescl chung la can giam 1\ so nen dong co den muc loi ihieii \ u a dam bao iihiel lii clia\ cua nhicn hcii plum ni6i II1.\M K I I U ) Mohamed Y hi Selmi .SV;iii/n;n ,,l'Jiiul liicI ,-n::iih iiicl ionipo\!!ion Energ> C o n \ c r s i o n and Nhmagci Pages 41 1-425 •nhtiMioi, uihl tiKH'kur^ Ijnuls lo ,^u.SL',na W.lumc 4.^ Issue v PelsruaiA : 0 J , K i n Dario Bedo>a Andres Amcll Arricla and Francisco hu ler (ãiida\ id /;7/ii7v ol iintini: \ >/iô; unil pilol fuel iimililx cm diesel-hiogiis dual lud cii;^im' iicrtonii.uiii' Bioresourcc Iechnolog> Volume 100 Issue 24, December 2001), Pages 6624-662') hup: n5>,ni edu ilresources manuals 11 uenl6,.Vhelp himl ug nodcT.sO htm, h^utnon MinL'l Theory I /\l' C Hi KHOA HQC & C N G NGHf CAC TRUING D;>I HQC K* THUAT * S6 86 - 2012 Biii Vdn Ga, Lg Minh Tien, Truang Le Bich Tram, Nguyen Van Dong, Hgn che phdt thdi ch gdy hl^u img nhd kinh vol cdng nghi' '''"^' diing sinh hgc tren dgng ca ddt trong, Tuygn ti Cong trinh Khoa hgc Hpi nghj Co hpc loan qudc l^n thir VIII, T?p I, pp 383-392 Ha Noi,; 9/4/2009 Bui Vdn Ga, Tran Vdn Nam, Truong Lg Bich Tram, Engines fueled by biogas: A contribution ^ energ\- saving and climate change miligution, The 6lh Seminar on Environment Science ar Technology Issues R>;lated to Climale Change Mitigation Japan-Vietnam Core Universil Program Osaka, Japan, 26-28 November 2008 Bui Van Ga, Tran Van Nam, Nguyen Thi Thanh Xuan, Utilization oj biogas engines in run area- A contribution to climate change mitigation, Colloque Internationa) RUNSUD 2010, p| 19-31, Universite Nice-Sophia Antipolis, France, 23-25 Mars 2010 Dia chi lien h^: Trdn Vdn Nam - Dai hpc Dd Ndng 41, Lc Duan, Tp Dd Ndng ... thdi digm bdt ddu chdy 2200 nhanh ciia hon hgp biogas- khon^ gidm di khodng 2ms Ket qua ndy cho thay chuyfin dpng ca diesel sang dpng co dual fuel biogasdiesel, chiing ta can giam ti s6 nen dpng co... qud tinh todn tren ddy dupe kigm chirng bang thuc nghiem trgn dpng co diesel dugc cdi tao thdnh dpng co dual fuel biogasdiesel: dpng CO D16 lap bp phu kien GATEC20 (hinh 9), dpng ca D24 lap bp... lieu biogas co ihanh ph;''ui the lich methane Ion hon S()"o ca hai dduL: Hinh D(m''^ a> dual fuel hio^zus-diescl vw hn phu kien G.iTEC khang en he !hau\i hai lim iluii /ji>,i, /i, [jo„u ca dual