Nghiên cứu ảnh hưởng của việc điều chỉnh góc phun sớm đến hàm lượng phát thải (NOx, bồ hóng) và công suất của động cơ diesel ở các chế độ tải khác nhau bằng phương pháp mô phỏng

Tap chi Khoa hoc - Cong nghe Thdy sdn So 2/20141 KET QUA NGHIEN CLfU D A O TAO SAU DAI HOC NGHIEN ClTU ANH HlTOfNG CUA VIEC 0IEU CHINH GOC PHUN S M DEN HAM LUONG PHAT THAI (NOx, BO HONG) VA C N G SUAT CUA DONG CO DIESEL Of CAC CHE DO TAI KHAC NHAU BANG PHU^ONG PHAP M PHONG STUDY EFFECTS OF EARLY TO SPRAY ANGLE ADJUSTMENT EMISSIONS LEVELS (NOx, SOOT) AND POWER OF DIESEL ENGINE LOAD INA DIFFERENT MODE BY SIMULATION Nguyen Nhgt Lai', Phung Minh l^ Ngay nhan bar 15/6/2013; Ngay phan bien thong qua: 25/11/2013; Ng^y duy^l dang- 02/6/2014 T O M TAT Bai bao ndy trinh bdy vi^c sd dung phdn mem mo phong da chieu KIVA de nghien ciru dnh huang cua goc phun sm den phdt thdi (NOx, bo hong) vd cdng sudt iren dpng co moi xy lanh A VL 5402 vdi cac che tdi 40%, 60%, 80% Kel qua mo phong dupc thuc nghiem kiim chung da chi gid tri lot uu cualhdi diem phun Iheo cdng sudt vd hdm lu(mgphdt that ciia dong co nghien ciiu Tir Idioa • gdc phun sdm, phdt thdi, phdn mem mo phdng KJVA ABSTRACT This paper presenls the use of simulation software to study multidimensional KJVA spray early influence oftheNOi emissions, soot, on an engine cylinder mode AVL 5402 with 40% 60% 80% loads The simulation results are verified experimentally showed optimal values ofinjection lime according lo the capacity and function of engine emissions research Keywords: early spray, exhaust, software simulation KIVA I DAT V A N o e Nhien lieu diesel dupe phun vdo buong ehdy chua ddy khbng cb nhiet db cao hdnh trinh ndn, do ning db eua hbn hpp nhien lieu vd khdng khf xy lanh tgi cac diem khde la khae Khi thai dupc hinh thdnh td kit qua eua qud trinh ehdy cua hbn hpp khbng khi/nhidn lidu khbng ding nhat Cde qud trinh hda trpn nhien lidu trudc chay nhu thdi gian ehdy tre, chat lupng tia phun, thdi gian luu tni eCia nhien lidu cac vung nhidt dp khde nhau, thdi gian gidn nd, thdng so phun nhien lieu dbng vai trd quan trpng viec hinh khf thdi [4] Ham lupng CO vd HC cua dbng ca diesel nhd han dbng ca xdng, nhung NOx vd b l hbng (muoi than, particulate matter- PM) cao han nhieu [5] Ddy ehinh Id diem yeu eua dpng ea diesel va d n nghien ciru khde phye Gldi quylt van d l tren la mbt nhigm vu rat phde tgp, chl cb t h l dgt duac bdng ket hpp dong thdi thyc nghidm vd md phdng Mb phdng (simulation) id phuang phdp mb hinh hba dya tren vide thiet lap mb hinh sd vd sir dgng phuang phap so dl fim idi gidi vdi sy trp- giCip eiia may tfnh [6] Mac dO eae thdng so mb phbng cb the khbng chlnh xac niiir thuc nghigm, phuang phdp ndy vdn ed nhung iw diem noi trpi vd huu ieh eho vigc phat tnln dbng ca Trdn quan dilm ndy, rb rang ddy la phuang phip "khdng t h l thilu" hign tai cdc trung tdm nghien cuu Idn tren t h l gidi, dgc bigt tien hdnh dc nghidn cdu v l bien d l i Uidng so, vi hidu qud cao han han vipc thay d l i kit d u dbng ca vd c» the nghien cdu trdn nhieu miu dbng ca khde Cde uu dilm ehinh ciia phuang phap hi6 phbng la: - Cd t h l thay d l i dd ddng tat ea d c thbng s6 c^n nghien cdu, - Cd the dp dgt cdc dieu ki^n ban d^u tren m$t dai r0ng; - Cb t h l nghien cuu tdch bigt tdng qud trinh tong t h l qud trinh chdy; ' Nguyen Nh|t Lai: Cao hpc Kyttiugttau thOy 2009 - Tnj-dng Dgi hgc Nha Trang = TS Phung Minh Lpc Khoa Ky thuat giao thong - Tnj-dng Dgi hgc Nha Trang 106 • TRLfONG OAI HOC NHA TRANG T^p chi Khoa hoc - Cong nghe Thdy sdn - Co the trich xuat thdng tin lien quan mpt each chi tilt va mpi liic; - Hieu qud cao v l thdi gian vd ehi phf Mbt nhtrng phin mlm mb phbng dbng iyc hpc da chieu mgnh la KIVA, duae phdt triln bdi Phdng thi nghiem Quoc gia Los Alamos (LANL) ciia My [3] Sy thdnh cbng eiia phin mem md phdng KIVA da dan din sy su dyng rbng rai KIVA tren t h l gidi, KIVA Id phan mlm md nguon md (open source code), edn cdc phan mem khde Id phin mlm md nguon dbng, hay d n gpi Id phan mlm thuang mgl [1], Vi vdy, vide nghien euu sd dung phin mem mb phbng da chieu KIVA de nghien cuu anh hudng ciia thdi dilm phun din vide phdt thai (NOx, bo hbng) vd cbng suat dpng ca la hit sue huu ich Kit qua md ptiong se udc doan kit qud thye nghipm dieu chinh toi uu gde phun sdm nhien ligu tnang dpng ea diesel II D | TU'Q'NG, THI^T B\, VA PHU'ONG PHAP NGHIEN CO'U D l i tup'ng va thiet bj nghien cOu - Dbi tupng nghidn edu: Dbng ea diesel mbt xy lanh AVL 5402 tgi Phbng thf nghiem Trpng dilm Dbng ca d i t Trudng Dai hpe Bach khoa, Ogi hoe Quoc gia Ho Chi Mtnh Dbng ca nghien euu d cdc thbng s6 ky thugt eho d bang Bang Thong so ky thudt dpng c v xy lanh AVL 5402 [2] TTiong so Giatri So xy ianh fiirang kinh xy lanii 85 mm Dung tich xy ianh 510 cm' nslnen 17:1 Nhien lieu Diesel Hethong nhien ligu Common Rail Cong suat cyc dai 18/4200 kW/rpm So Iu'p'ng xu pAp nap, thai Kieu xy lanh Lfdt He thong phoi Mif DOHC Then ffiem phoi Thon d i ^ xu pdp nap mo BdegBTDC kyxa Then diem xu pap nap dong 134degBTDC kynen Th£n diem xu pap xa mb 128degATDC kynen Thfri diem xu p^p xa dbng 18degATDC_ki'xa Ifim phun Kieu kim phun Bosch CPl 1350Bar So l5 tia X dirdnq kinh x goc phun X 0.17mm X 142° Luu It/ang 375ml/30s Dd nang kim 2mm G6c phun Sffm ISdegBTDC - Thilt bi nghidn edu: Gbm may tinh phan mem KIVA3V vd thiet bj AVL bo tri tren hinh Hinh I Sot bo t r i chung thiet bi AVX phyc vg nghi Phirang phdp nghien cipu Ly thuylt (mb phdng), thyc nghigm kiem chdng III K^T QUA NGHIEN CI>U VA T H A O LUAN Qud trinh chay ciia dpng ca se bit dau xdy sau phun nhien lieu mpt thdi gian ngdn (Id thdi gian chdy tre), dd nlu nhien lieu dupc phun diing luc khien sy chay biing phat cubi hdnh trinh nen se tgo iyc day manh len piston, thyc hien hdnh trinh sinh cbng vdi ap iyc chdy toi da Nhd vgy ebng suat dpng ca se gia tang Nguac lai, nlu phun nhien ligu trd, nhiet dp va dp suat buong ehay cao, thdi gian chay t r i nit ngan, dp suat buong ehdy se giam Thdm vao db, hon hap khf chdy chua ehdy hit thi da sang ky thai, lam cdng suit dbng ea giam vd suat tidu hao nhien ligu gia tang Khi gde phun sdm edng nhd {phun nhien lieu tiln gan dilm ehit tren) dp suit eye dgi va nhipt dp cue dgi gidm khiln giam lupng NOx hinh thanh, vi NOx rat nhay edm vdi su biln thien nhigt dp Tuy nhien, nhiet db gidm khiln qud trinh dit ehdy b l hong sinh cung gidm, khien lupng bo hbng phat thai gia tang KIVA3V la ehuong trinh may tinh dung de md phdng cac qua trinh cua dbng ea dot noi chung va qua trinh phun nhien ligu eua dbng ca diesel nbi neng, Clu triie cua chuang trinh gom phin chfnh' - "Pre - processor": k3prep - chuang trinh dung d l tgo ludi cho mb hinh; - "Main - processor", kivaSv - chuang trinh xd iy chi'nh; - "Post - processor": Ongin + Tecplot - chuang trinh tao bieu do, hinh anh Vdi muc dfeh ddnh gia cac thbng so cua qua trinh phun nhu thdi dilm phun vd thdi gian phun den dac tinh cbng sull vd phat thai dpng ea thd nghiem, md phbng se dupe Ihyc hien theo bang TRLTONG OAI HOC NHA TRANG • 107 So 2/2014 Tap chi Khoa hoc - Cong ngh$ Thdy sdn Vigc tgo md hinh ludi diJng ea AVL 5402 KIVA3V dya vao d e thdng s6 dau vdo (bdng 2) Ngodi d n xde dinh cdc thdng s6 k i t d u khde eua dpng ea nghien cdu nhu: vi tri vd bien dgng hinh hpe eua buong chdy tren dinh piston Gdc md phdng dupc xde djnh bing 72" - tuang trung cho 1/5 khbng gian buong dit, gbe mb phong xdc djnh dya vdo kim phun sd dyng trdn dpng ea nghidn cuu AVL la loai lo tia vd k i t d u hinh hpc ciia buing dit dli xung qua dudng tdm xy lanh, Sau xac djnh cdc thbng so d n thilt cho t§p tin dau vao Iprep.brt Kit qua thu dupe mpt md hinh ludi ciia dbng ca AVL vdi gdc mb phbng 72° Vigc mb phdng se tien hdnh cho c h l dp tai khac nhau: 40% (non tdi), 60% (trung tdi) vd 80% (day tdi) 6' mbi ehe dp, d i u tien se thay doi thdi dllm phun, tir -22°ATDC den -40"ATDC, vdi moi lln thay doi Id 2° gbe quay trye khuyu (10 diem) Nhu vdy d X 10 = 30 lan mb phdng Sau dd, d mbi c h l dp tai se ehpn mbt thdi diem phun eb dae tinh khf thdi vd d n g suit tot nhat Giir nguyen thdi dilm phun vd luu iupng phun, thay doi thdi gian phun tu 5° den 14° gde quay true khuyu, mbi ian thay doi 1° (9 lan) Ta cb x = 27 lan mb phbng Tong cbng Id 57 ian mb phdng thuc hign theo bang Sy b i l n thidn cua NOx vd B l hdng theo m diem phun ir 40% tai Hinh Bi^n thiSn NOi thay dSi thoi diSm phEB, 40% tiii Cb hai nhdn xet n l i bgt: Thd nhat, thdi dilm phun d n g tr^ thi NOx d n g gidm; Thu hai, thdi dien phun d n g tre thi dp doc eiia dudng cong NOxcSng thoai thoai, nghTa ia tie dp hinh thdnh NOx se gi Sy biln thien cCia bo hbng chia idm hai nhfim | rb rdt Khi thdi dilm phun t r i dan td -22°ATDC den j -M^ATDC, bo hbng phdt thai gidm ddn, nhung tu -14''ATDC den ^ ^ ATDC lgi tdng dan Nhu vay gia dogn dau, bo hbng khdng tuan theo quy luat la NOx giam ddn thi bo hbng se tang dan, md bo hong ciJng gidm dong thdi vdi NOx Dua tren ket qua mb phbng ndy, d the xac djnh duac thdi dilm va thdi gian phun ndo id tbt nhat theo dae tinh cbng suat vd phat thdi cua dbng ca Bang Thong so md phdng Giatri Thong so qud trinh mo ph6ng Thong s6 hinh hoc mo phong (thsect) 720" Toe dgng co' 2000 vong/phijt Thffi (3iem xu pap nap dong (IVC) 134 degBTDC-kynen Thoi diem xu pap xa mo (EVO) 128 degATDC-kynen Nhiet ttianh xy ianh 400»K Nhi^t dp dinh piston 400° K Nhi^t dp nap quy ISt 400" K Thdi diem phun 4«-22»BTDC,btroc2" Tai 40%, 60%, 80% Thffi gian phun (gdc quay tnjc khuyu) 50-140 b u d d " Nhi^n lieu dac tarng c,A G6c phun (tia nhien ii^u) 142° Ap suat iai IVC 926 Bar Nhigt dp tai IVC 313°K Tlsoxoayl&cbandau 1.0 Nhiet dg fia nhign lieu ban dau 320"K 108 • TRUONG OAI HOC NHA TRANG ;_„ 7^mnh Bien thign b^ h6ng thay abi thori ailm phun, 40% tai Sy b i l n thien cCIa NOx va Bo hong theo thW d i l m phun o- 60% tdi Crank AnBlo deg Hinh Bien thiln NOx thay doi thiri dilm phon, 60% lii Sd 2/2014 T(fp chi Khoa hoc - Con^ nghe Thuy san Khi thdi dllm phun cang tre thi NOx phdt thai cdng giam Rieng trudng hpp -22''ATDC, nhigt dp buing chay nhd han so vdi trudng hpp -20''ATDC nen gid trj cua NOx nhb han, diJ thdi dilm phun sdm han 2" CA Quy lugt bien doi cua phdt thai b l hbng ngupe so vdi NOx: Khi thdi dilm phun cang t r i thi bo hdng phdt thai cdng tdng Tuy nhien, phun qud t r i nhu trudng hpp -e^ATOC vd -4''ATDC thi bo hdng Biln thiSn bo hong Ihay doi then dilm 60% tai iai gidm Bang Gia tri cong suat , suSt ti£u hao nhidn lieu, 40x va bo hong phat thai 60% tai Ne, (kW) g (9/kWh) NOx, (x10-"g) PM, (x10-"g) 22* -20' •18' -16° -14° -12° -10° -8' -6' 5.63 235.1 10.5 0.91 5.80 228.6 10.8 0.75 6.19 214.1 99 10 6.40 207.0 9.5 108 6.37 208.1 7.7 1.01 32 209.4 6,5 1.19 634 209.0 4.4 1.34 6.04 219.2 2.7 1.53 5.79 228.7 1.8 1.46 -4° 5.56 238.4 1.4 1.48 Si^ bien thien cua NOx vd Bo hong theo thdi diem phun cr 80% tai Hinh Bien thien ho hong kbi thay dfti thM diem phun, 80% Ui 80% tai Do nhidt db giam ^ilu kign d n thiet d l NOx hinh Khi thdi dilm phun cang gdn TDC, thdi gian ehay trd cdng ngdn vd nhidt db, dp suat d n g gidm khbng cbn, tir db NOx giam mgnh Trdi ngupe Sy thay d l i eCia nhidt dp anh hudng Idn d i n NOx vdi NOx, bd hbng gia tang phun t r i Bang Gia tri cong s u i t , s u i t tidu hao nhien lieu, NOx va bo hong phat thai 80% t i i Hinh Bien thien NOs tbay d6i thcri d i l m phun, Ne, (kW) g., (gftWh) NOx, (x10^ g) PM, (xio-' g) -22" 6.24 246.1 11.4 0,73 -20" 6.83 225.5 11.6 0.53 -18' 7.14 215.9 11.1 51 -16" 7.26 212.2 9.79 0.62 -14" 7.45 206.7 7.96 0.87 -12" 7.46 206 5,35 0.99 -10" 7.28 211.6 3.20 1.16 -8" 6.93 222.3 1.42 1.36 -6" 56 235.1 0.70 1.62 -4" 6.16 250.0 0.28 1.97 Hinh Biln Ihien c6ng su&l theo tai trf ng vi thiri dilm phun T R U O N G OAI HOC NHA TRANG • 109 Tap chi Khoa hgc - Cong nghe Thdy sdn So 2/2014 ThM'C nghiem gbe phun sdm: 18°BTDC, vdi ba ehe dp tai Id 40%, Tien hanh eho dOng ca thyc nghipm chay d so 60% vd 80%, dupe thilt lgp bdng edeh thay floj iupng nhidn li$u phun tuang ung vbng quay 2000 v/phut (bo tri thiet b] trdn hinh 1), Bang So sanh ket qua thyc nghidm vd md phong STT D^i llidng 40% t i i GO%tal 80% t i l T h ^ nghidm M6 ph6ng T h ^ nghifm M6 phdng T h ^ nghilm M& phdng 6.19 7.05 7.14 9.9 1.0 12.3 0.55 0.51 Ne, (kW) 5.25 5,30 NOx, (xio-" g) 6.77 6,68 6.11 10 PM, (xlO-ig) 0.86 0,83 1.12 Cde thbng s l dupe ghi nhdn Id d n g suat dbng ea vd ehit dbe hai phdt thai Tgi moi dilm do, kit qud Id tri sb trung binh cua 1000 ehu Wy S l lln thd nghidm tai mil dilm id ian, k i t qua ddnh gid Id k i t qud tnjng binh eua l l n thu Bang trinh bay k l l qua thye nghidm dol ehung vdi mb phong Cde thbng s l dupe tu thye nghidm thudng xau han mb phbng ede dilu kidn bidn, tham s6 dau vao mb phdng khbng t h l hign hit dupc cde ton that cua chu trinh cdng tac IV K^T LUAN Khi thay doi thdi dilm phun, dya tren cde k i t qua mb phbng vd thye nghidm da Wnh bay d tren, eb mbt so k i t luan sau: 111 - Thdi dilm phun cang mubn thl lupng NOx phdt thdi d n g gidm Vdi d n g mpt thdi dilm phun,j nhin chung dpng ca hoat dbng d chl dp tai ldn honj d lupng NOx phdt thdi Idn han fl - Thdi dllm phun cdng mupn thi lupng b l hbng phdt thdi edng tang Vdi cung mbt thdi dilm phun, nhin chung dbng ca boat dpng d ehl db tdi Idn hon • eb lupng bo hdng phdt thai idn han ^| - Khi thay doi thdi dilm phun, d n g suit se dgi gia trj cyc dgi mpt khoang ndo db Phun sdm hay t r i han d i u lam giam d n g suat (hinh 8) - Thye nghiem tren dbng ca nghidn cuu AVL 5402, tai nhb va vira, phun d thdi diem -le^ATDC la toi mi, nhung tang tdi Idn 80%, thbi dilm phun tli uu se bl han d -14