So sánh mô phỏng và thực nghiệm các thông số chỉ thị của động cơ xe gắn máy chạy bằng biogas nén

TAP Clli KHOA HOC & CONG NGHE C4C TRl'ONG DAI HOC KV Till XT * SO OS - 2014 SO SANH MO PHONG VA THlTC NGHIEM CAC THONG S CHI TBI CUA ©ONG CO XE GAN MAY CHAY BANG BIOGAS NEN COMPARISON OF INDICATING PARAMETERS OF MOTORCYCLE ENGINE FUELED WITH COMPRESSED BIOGAS Tr^n Vdn Nam, Biii VHn Ga, Nguyen Van Bong Truang Dai hoc Dd Ndng Din Toa soan 10-6-2013, chdp nhdn dang 25-12-2013 TOM TAT So sanh ap suSt chi thi va thi cong chi thi cho boi mo pliong va thwe nghiem dwac thi/c hien doi V&I dong ea xe gin may WA VE a-11 Occ ciiay bang biogas nen Nghien ciru mo phong dwa tren phSn mSm dong hoc Iwu chSt FLUENT Nghien ciru thwc nghiem dwac thuc hien tren bang thCfxe gan may A VL K4t qua cho thSy dong ca ehay a che loc dd trung binh pham vi tir 3000 vong/phiit din 6000 vong/phiit b§ng biogas chua 85% CH4, he so chay roi la 1,3 Cong chi thi chu tnnh cua dong CO tang tuyen tinh theo phan CHa biogas ii'ng vai dam dac cua hdn hap cho trwac TLF khda' toe chay, biogas nen, CHi ABSTRACT Comparison of indicating pressure and indicating cycle work given by simulation and experiment IS carried out on motorcycle WAVE a-11 Occ engine fueled with compressed biogas Simulation study is based on fluid dynamics software FLUENT Experimental studies were pedormed on A VL motorcycle dynamometer The results showed that when the engine runs at an average speed in the range of 3000 rpm to 6000 rpm with biogas containing 80% CH4, turbulent burning coefficient is 1.3 Indicating cycle work increases linearly with CH4 component in biogas at a given equivalent ratio Gioi thieu Toe dg chay chdy tang (Si) va he so toe chdy chay roi (ff) Id cdc thong so quan md phong qua trinh chay dgng co danh lii'a cudng birc sir dung biogas Nhiing thong tin chi CO the nhdn dugc mdt each day dii nhd phdn tich dudng cong dp sudt chi thi bu6ng chdy ciia dong ca Ket hgp giua thuc nghiem ti en bang thu Chassis Dynamometer 20" vdi nghien cim mo phdng dua tren phan mem dgng luc hgc hru chat FLUENT giiip chiing ta phan tich dien biln ap suat buong chdy dgng ca xe gdn mdy Honda wave a lOcc sir dung nhien lieu biogas nen 85% CH4, d che dp van hanh: dg dam dac tuang duang ciia h6n hgp ^=1, t6c trung binh 3000 vdng/phiit den 5360 vdng/phut, goc ddnh lua sdm 27" vd phan biogas cd 85% CH4 Trong thuc te qud trinh chay chay r6i dien budng chay lam tang toe truyin nhiet va truyen chat viing phan img, dd lam tdng tdc lan trdn mang Ida vdi quan he giCra toe dp chay chay tang va chay chay roi nhu sau: / / • - S, (I) Trong S,, Si lan lugt la toe dd chdy chay rli va chdy chdy tang; s Id d6 khuich tan rdi tdng cong; v la dp nhdt dgng hpc cua h6n hgp chira chay Cdc thdng s6 ndy dugc xdc dinh bdng thuc nghiem vdi hdn hgp nhien lieu tinh khilt va khdng D6i vdi nhien lieu biogas, phdn CH4 va tap chat thay doi nen viec dac thuc nghiem phuc tap va tdn thdi gian han Mat khac, tdc dp chdy chay tdng cdn phu thugc vao nhiet d5 va ap suat ciia hdn hgp chua chay Cac dilu kien ndy thay doi qua trinh chdy ciia dong co ddt Cho nen, cd thi xem qua trinh chdy nhien Heu biogas nhu bdn hgp bi pha ban bdi chdy, quan he t6c chay chay tdng dupe the hien nhu sau [1]: 5;-5,„(a„+fl|ej + fl/)[l-(i,Z) + i j D ^ j D ' l p UJ (2) TAP CHi KHOA HOC & CONG NGHE CAC TRI OING DAI HQC KV THI \T S6 98 - 2014 Trong dd Sl' Tdc dp chay chay tdng (cm/s) Si,,v Toe chay chay tang d diem tham chilu (1 atm va 298K) (cm/s) D: Phdn trdm (theo the tich) chdt lam bdn hdn hgp Tui Nhiet chua chay (K) To: Nhiet dg tham chilu=298K P: Ap suat ciia hdn hgp (atm) Po: Ap sudt tham chilu Cdc he sd lai co the tham khdo [ ] M Eiia, M Ulinski, M Metghalchi daxdy dung dugc moi quan he giii-a t6c dp chdy chay tang vdi cac ihdng s6 Ij- - hoa cua h6n hop trudc chdy [2] R Stone va A Clarke [3] da tiln hanh thi nghiem xac dinh tdc chdy chdy tdng ciia hon hgp nhien lieu CH-i dugc lam bdn bdi CO: vd khdng Nlu goi nhiet vd dp sudt khcing thd nguyen T=T,|/T„ va P=P„/Po Til, P„ Id nhiijt d6 va ap suat ciia h5n hgp chua chdy; T,, vd Po Id nhiet d6 vd dp sudt d dilu kien lap bdng thi toe dg chdy chay tang ciia hon hgp methane khdng cd the dugc xdc lap bdi bieu thdc bdn thuc nghiem sau: Si=0,366T''''-p-'' "(m/s) (3) Theo Rallis vd Garforth [4] mdi quan he girra tdc dg chay chay tang ciia hon hgp methane/khong d dieu kien chdy hodn loan dugc bieu dien bdng bieu thdc: S)=S,J"- (4) Trong HQ ndni khodng 1.37 vd 2,33 Moi day Hill vd Hung [5] ddi vdi dieu kien chdy hodn toan tim s6 mu a ciia T Id 1,80 lijima va Takedo [6] lim bieu thirc tong quat sau: a=l,60+0.22((|)-i) S,-S,_J"{]+/3\og,^P) (7) Trong ddp=-0,42-0.31((1)-1) Nhu vay nghien ciru md phong qua trinh chay nhien lieu biogas buong chay ddng CO chung ta cd the tinh toan t6c dp chay chay tang dua vdo nhQng cdng trinh dd c6ng bo tren day va xay dung dugc dien bien dp sudt chi thi budng chdy theo cac phan nhien lieu biogas khde dng vdi cac he s6 tic dp chay roi ff tuang dng Nghien cuu mo hinh hoa Qua trinh chay biogas dpng co dirge mo phong dua tren nen phan mem dpng lire hgc chdt long FLUENT Cac thong so k^t cdu va van hanh ciia dong ca dugc dua vao chuang trinh tinh thdng qua option dynamic mesh Tinh chSt nhiet ddng hpc cua moi chat c6ng tac dugc thilt lap bang PrePDF tich hgp phan mIm FLUENT Qua trinh chay roi buong chdy dugc md phong bang mo hinh roi k-E, md hinh chay hda trgn trirdc cue bo {Partial Premixed) voi tde mang lira chay tdng (Laminar Flame Speed) dugc xdc dinh theo thuc nghiem img vdi nhien lieuchii-ahai phdn chinh CH4 vaCO2 trinh bav a tren iStt (5) Sir phu thugc toe chay chay tang ciia hdn hgp methane/khdng vao dp suat ddieu kien chay hodn todn dugc Andrew va Bradley [7] xac lap nhu sau: Si = 43,3P-''''(cm/s) Rallis va Garforth [4] de nghj p= -0.3 d dieu kien dp suat ! bar dd Hill and Hung [5] dl nghi p= -0.299 ddi vdi dp sudt nam khoang 0.2 den I bar lijima va Takedo [6] de nghi bieu thuc tdng quat sau: (6) Trong dd P la dp sudl dugc linh theo bar S6 mu ciia P thay ddi nhe theo cac tdc gia nghien ciru hon hap chay methane/khong a) b) Hinh Kich thudc cua xi lanh-hudng chdy ddng caxe gdn mdy W.4VE a-11 Occ (a) vd chia tudi khong gian tinh todn (h) Hinh gidi thieu kich thudc xi lanh budng chdy dgng ca va chia ludi khong gian tinh toan De tranh the tich phan tu dm bj biln dang qud trinh piston dich chuyen ta chia ludi I AP CHi KHOA HQC & CONG NGHE CAC TRlOiNG DAI HQC KV Till \ \ * SO 98 - 2014 khdng gian xi lanh va budng chdy khac (hinh lb) Hinh gidi thieu ket qud tieu bieu dien bien qud trinh chdy, bien thien nhiet va dp sudt ciia moi chdt xi lanh cua dgng ca xe Honda wave a 11 Occ chay bang biogas nen chua 85% CHj Chiing ta thdy ban ddu mdng lua cd dang chdm cdu sau lan ddn xa khong gian buong chdy Dd thj cho thdy dp sudt dat cue dai khoang 13 sau diem chet tren Nhiet dat cue dai sau dd khoang dp nang k^ thuat cua ddng ca xe gdn mdy Honda wave a lOcc ^- \\- t L Hinh 3a vd hinh 3b gidi thieu bien thien dp suat chi thi cho bdi md hinh mo phong vdi he Y sd toe dp chay chay roi ff= —^ dugc chpn Id 1,2, 1.3 va 1,5 „ _ Hinh 4a va hinh 4b bien thien ap sudt chi thi cho bdi mo hinh ung vdi he so toe chay S chay roi ff^ —^ dugc chpn la 1,3 va 1,5 De dam bdo dp tin cay ciia mo hinh, phdn sau day tien hanh nghien cuu thuc nghiem kiem chung mdt so trudng hgp Sir dung md hinh sau da hieu chinh theo cac thong sd thuc nghiem de du doan anh hudng cua dam ddc h6n hgp va phan nhien lieu din tinh - V _\ -l-V- - -A- L Hinh Bien thien dp sudt nhiel vd didn hien ndng CH^ hudng chdy ddng ca WA VE chay hdng biogas nen chira 85 % CH4 a) n - 3000 vdng/phut b) n = 3620 vdng/phut Hmh 3- Bien thien dp sudt chi ihi cho hdi md hinh md phdng (gdc ddnh lira sdm tp, = 27", biogas chiea 85% CHj ^=1) ung vdi tdc dd gdc true khiiyu ddng ca n = 3000 vdng/phiit vd n = 3620 vdng/phiil TAP Clli KIIOA HQC & CONG NGHE CAC TRI ONG D^I HQC KV THU:^T * SO 98 - 2014 a) n = 4070 vong/phiit b) n = 5360 vdng/phiil Hinh Bien thien dp sudt chi thi cho baimd hinh mo phdng (gdc ddnh lira sdm (p = 27" biogas chiea 85% CHj, ^= 1) img vdi tdc gdc true khuyu ddng can - 4070 vdng/phiil vd n ^ 5360 vdng/phiil Nghien cuu thuc nghiem Thi nghiem dugc tien hdnh tai phong thi nghiem Dpng ca - td A VL cua Trudng Dai hgc Bach Khoa Hd Ngi Cae thiel bi phuc vu Ihi nghiSm gom bdng thu xe mdy CD20" thiet bj dien bien dp sudl buong chay ddng co, tii phan tich xa CEBII, dugc bd Iri nhu hinh 5a Khi thu nghiem bdnh sau ciia xe dugc dat vdo vi tri giua cua dynamometer, bdnh trudc dugc gift bdi CO cdu kep xe dugc giu: dn djnh chdng quay ngang bdi hai day an toan suot qua trinh thir Thiet bj Indiset 620 gdm: mdy tinh ghi nhdn lin hieu va cai dat cac loai cam bien bang phan men IndiWin620 Trong giao dien ndy tii'ng loai cdm bifn dugc khai bao cu the cac thdng sd ky ihuat de ghi nhan tin hieu vd pham vi boat dgng irong thir nghiem Qua trinh ghi du lieu duoc thuc bien lien tuc nham kiem tra tin hieu ciia timg loai cam bien sir dung Cac thdng so chi thj ciia dgng ca dugc ghi nhan g6m: diin bien dp sudt budng chay, tin hieu kich nd, goc ddnh lira hay gdc phun sdm, xdc djnh vj tri diem chet tren Nguon dLJ" lieu thuc nghiem dugc phan tich, danh gid va ket qud dugc xuat bang phdn mem chuyen dung Concerto Cam bien tdc su dung Encoder 364C cd khd ndng ldm viec dugc moi trudng khac nghiet nhu nhiet cao vd rung dpng ldn Cam bien ket hop vdi bd md hoa quang hgc co ,ji ddng bp de dam bdo dp chinh xac cua ket qua thi nghiem Thi nghiem dugc thuc hien trudc tien vdi nhien lieu xang RON92 de kiem tra su boat dgng dn dinh ciia he thdng Phan thi nghiem chinh se tien hdnh voi nhien lieu biogas nen chiia cdc binh dp lire Viec cung cap nhien lieu biogas nen cho dpng co dugc thuc hien nhd bg phu kien Hinh Sa dd tdng quat cdc trang thiel bi Irong phdng thu nghiem xe mdy (a), sa he thdng bdng thu Chassis Dynamometer 20" (b) vd ho iri xe gdn mdy chay bdng biogas nen Ien hdng thu (c) TAP CHi KHOA HQC & CONG NGHE CAC TRI OTS'G BAI ]H)C KS THUAT SO 98 - 2014 GATEC 25 Sau hoan tat thir nghiem tren bang thu, xe gan may biogas nen dugc chay tr6n dudng de ddnh gia tinh irang ky thuat T" ] ,_*a gRCI.e ^ B "B.oga A s."oC - H \ \ \ - V a) b) Hinh So sdnh hien thien dp sudt chi thi (a) vd thi cdng (b) ciia xe gdn md)' -wave a llOcc cho hdi thuc nghiem chay bdng xdng RON92 vd chay hdng biogas nen chira 85% CH.i Hinh 6a,b so sanh dp sudt chi thj va d6 thj cong ciia d6ng ca xe Honda wave a 11 Occ chay bang xdng RON92 va chay bdng biogas chira 85% CFL d ciing dilu kien van hanh Kit qua cho thdy dp sudt chi thi cue dai ddng ca chay bdng xdng dat 57,5 bar dp suit chi thi cue dai ddng co chay bdng biogas la 35 bar Su lui giam dp sudl cue dai chuyen tu xang sang biogas cd the dugc giai thich bdi ly Thd nhdt la su giam he sd nap su dimg nhien lieu thd hai la COz biogas la bdn lam giam nhiel tri va chat lugng qua trinh chay cua dgng ca Kel qud Id cdng chi thi chu trinh ciia ddng ca chay bang biogas nen chira 85% CH4 chi bdng 72% chay bdng xdng RON92 So s^nh ket qua cho bdi md hinh va thu'c nghiem Cdc ket qua sau day trinh bdy so sdnh dp suat chi thi cho bdi md hinh va thuc nghiem ung vdi cdc che tdc khac Nhien lieu sir dung Id biogas nen chira 85% CH4 Gdc danh lira sdm ciia dOng co dugc c6 djnh d 27" Kit qua thuc nghiem cho thdy goc ddnh lira sdm khdng thay ddi thi tdc ddng co cang cao, dp sudt chi thi cue dai cang be fr=-.5 X 1=1 3^ 1' \ / r 1.; s ff fM t" s ^ • * j'T -J ^ I t it ^5 > ^^* * !1 5- ,?- 13 3\K g ^S t =1%^ J—l—l-Et-J—I—1—1—1—1—J—I—I i " ^ 60 ]3 t i S-io a 15 • 120 180 240 300 Goc quay true khuyu (dp) a n=3000 vdng/phiil 60 120 180 240 300 Goc quay true khuyu (36] q-'^'= f - i y i fe JI t1%\ ~^'^V~ , '/ 1=1,k^ iX t I L 10 t^x | - — a G6c quay Iryc ktlLiyu (a6| 360 b n=3620 vdng/phut ^ 60 JL ^^ ^ 120 ^ 180 240 300 360 Goc quay true khuyu (dp) c n^4070 vdng/phut d n=5360 vdng/phut Hinh So sdnh ket qud bien thien dp sudt chi thicho bdi md hinh vd ihuc nghiem (goc ddnh lira sdm (p.=27^, biogas chira 85% CH^.tji^I) T^P CHI KHOA HQC & CONG NGH$ CAC TRI CfNG DAI HQC KV THl'AT « SO 98 - 2014 Hinh 7a vd hinh 7b so sanh ket qua dp sudt cbl thi cho bai md hinh va thuc nghiem a t6c dp dpng ca 3000 vdng/phiil va 3620 vdng/phiit He sd tdc dp chdy chay roi ff dugc chpn Id 1,2: 1,3 va 1,5 Ket qua cho thdy he sd dp chay chay roi ff = 1,3 phii hgp vdi thuc nghiem He sd ndy cung phii hgp vdi trudng hgp n=4070 vdng/phiit (hinh 7c) Khi tdc ddng co lang Ien din 5360 vdng/phiit dp suat chi thj cue dai giam nhanh, neu su dung he so toe dp chdy chay rdi fr =1,3 nbu cdc trudng hgp tren thi ap sudt chi lh| cue dai cho bai mo hinh Idn ban dp sudt cue dai cho bdi thuc nghiem khodng 10% (hinh 7d) Ket qua nghien cuu tren ddy cho phep chimg ta riit dugc nbdn^ ket luan: He sd tde d6 chay chay roi buong chay dong ca xe gdn may WAVE chay bdng biogas nen chira 85% CH4 CO the lay gdn diing la 1.3 dgng co boat dong pham vi toe dg trung binh tir 3000 vong/phut den 6000 vdng/phiit Mo phong anh hudng ciia nhien lieu biogas den tfnh nang cong tac cua dong co' xe may Sau ddy ta su dung mo binh co be sd loc chay roi fr = l,3 de dudoan dnh hudng ciia dp d^m dac hon hgp va phan nhien lieu biogas den linh ndng cong tac ciia dgng ca Hinh 8a 8b gidi thieu bien thien ndng dp CH4 vd O2 budng chdy ddng co chay a tdc 3000 vong/phiit, gdc danh lua sdm 30" vdi dam ddc ciia h6n hgp la 0,9; vd 1,5 Dp d6e ciia cac dudng cong the hien tic dp tieu thu ciia nhien lieu va chat oxy hda Khi ddc cang cao thi loc tieu thu hon hgp cang cao Ket qua ndy cho thdy phan hdn hgp ^-1 thi tdc dp tieu thu hon hgp cao nhdt Khi (|)=0,9 thi giai doan ddu cua qud trinh chay, toe chay khong khde biet so vdi trudng hgp i^-1 ithung a cudi qud trinh chay, su khde biet ve toe chay the hien ro tren dudng cong biln thien O2 Dudng cong biln thien CH4 va O2 ung vdi (|)=1,5 thodi hon nhieu so vdi hai trudng hgp lai Hinh 9a va hinb 9b gidi thieu bien thien thi dp sudt chi thi vd d6 thj cdng chi thi theo dam ddc tuong duong ciia hon hop ij) dgng CO chay a tdc 3000 vong/phiit, gdc ddnh liia sdm 30" va nhien lieu biogas chu'a 85% CH4 Cong chi thj ciia ddng ca the hi^n vd dien tich mat phdng gidi han bdi dudng cong nen va dan nd Ket qua bien thien cdng chi thj theo dp dam ddc ciia hdn hgp ^ dugc trinh bay tren hinb 10 Ta thdy cong chi thj ciia dpng co dat gia trj cue dai irng vdi (j) nam khoang td I den 1,1 dng vdi viing tdc chay dat gid tri cao nhdt 20 lig "!::::: •EE V 15 f 19 ' \1 |12 »• ,5 •? -\—Ft" ikiiii i: \/ \ ^ V 180 240 300 Iruc khuyu (do) 80 Zffl 300 JC khuyu (da) Hiiih Bien thien nong ^6 CHj fa) va nong O2 (h) Iheo goc quay Iriic Ichiiyii dong ca Irong qua Irinh chdy (n=3000 vdng/phiil, i/).=3(/', liiogas chira 85% CHj il>=I) A*-i' 13 »E" J^VlF.4 St" tt ^^ _^-' h*A'i^ «^ - LL-' S I = - ^3