NGHIEN CUU - TRAO Dpi
NGHIEN CU'U ANH HUONG CUA NHIEN LIEU LEN XE CAN MAY
STUDY O N EFFECTS O F FUELS O N MOTORCYCLE
Nguyen Ngpc Dung
Phong Thi nghiem Trong diem Dpng co Dot trong, Khoa Ky thuat Giao thong, Trudng Dai hpe Bach khoa TP. HCM.
TOM TAT
Viec sii diing nhien lieu khong dung theo tieu chuan cd the gdy nhieu tdc dong len dgng cd vd xe gdn mdy. Muc tieu chinh cua de tdi ndy nhdm ddnh gid dnh hudng ciia viec sil dung nhien lieu khdng dung tieu chudn len he thong nhien lieu, nhiet do dgng cd vd nhiet do mgt so khu vttc tren xe gdn mdy. Xe thii nghiem dUdc lap tren be thUxegdn mdy vd chay vdi 17 loai nhien lieu dUdcpha iron vdi tile ethanol/
methanol khde nhau. Ket qud thii nghiem cho thdy viec sii ditng nhien lieu xdng pha con cd the tdc dgng ldm phd huy he thdng nhien lieu xe. Thanh phdn nhien lieu thay dgi ldm thay dgi nhiet do dgng cd vd nhiet do mgt so khu viic tren xe. Viec nghien citu ddnh gid tdc dgng cua nhien lieu len xe gdn mdy gdp phdn xdc dinh nguyen nhdn gdy ra chdy xe tgi Viet Nam.
Tii khoa: Nhien lieu, nhiet do ddng cd, xe gdn mdy, chdy xe.
ABSTRACT
The using of unstandard fuel may cause serious problem to engine and motorcycles. The main objective of this research is to study the effect of using various unstandard fuels on fuel system, engine temperature and other parts of motorcycles. The tested scooter was setup on a chassis dynamometer and fuelled by 17 mixed fuels with difference ethanol/methanol amount. The results showed that the using of
mixed gasoline and methanol/ethanol may damage fuel system. In addition, the changing of fuel proper- ties caused the variation of engine temperature and temperature in some parts of tested motorcycle. The founding results contributed for the study to determine motorcycles and vehicle burning in Vietnam.
Keywords: Fuel, engine temperature, motorcycles, vehicle buring.
I. GlOd T H l £ u trinh chay xay ra vdi nhien lieu, vat lieu de chay xay khi: Nhien lieu, vat lieu de chay ket hop vcli Qua trinh chay nhien lieu la mot phan mpt so lupng day dii chat 6 xy hoa ching han nhu ling oxy hoa xay ra rat nhanh cua nhien lieu do oxy hoac hpp chat giau oxy va dupc tiep xiic vdi kim theo sU t6a nhiet, phat sang va cac san pham nguon hoac moi trUdng xung quanh co nhiet dp khac nhau. Nang lupng hoat hoa de xay ra phan tren nhiet dp chdp chay cua hon hpp. Qua trinh ling chay tiiy thupc vao ban chat vat ly cua nhien nay se dupc duy tri blng nang lupng sinh ra til lifu |1,2]. Dilng tren quan diem hoa hpe, qua qua trinh chay ngay trUdc dd | 3 | .
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NGHIEN C I J U - T R A O D O I
Sfl chay cfla cic phflong tiin giao thong van tai co the xay ra do sfl tiep xuc cfla nhien lieu hoac vat lieu d i chay v6i nguon nhiit Icfn vfla dfl ldn do chap mach dien, do cac cac chi tiet tren phuong tien tiep xuc v6i nguon nhiit sinh ra tfl q u i trinh dong co van hanh, do ma sat sinh ra khi phfldng tiin van hanh hoac nguon nhiit do con ngfldi tao ra (dot, hut thuoc li) [4]. Ngoai ra, mpt nguyin n h i n khac co the xay ra l i sfl xuit phat nguon nhiet tfl cac phan flng cua cac hdp chat Perroxide hmh t h i n h trong q u i trinh phoi trpn nhien lieu.
Viic sfl dung nhien lieu khong dung theo tieu chuan Viet Nam ve chat Iflpng xang dau dflpc danh gii la mpt trong nhflng nguyin nhan quan trpng trong viic gay ra chay xe. Tuy nhiin, cic nghiin cflu vi viic d i n h gia tic dpng cfla viec sfl dung nhien lieu khong dung chuan (xang pha thim con methanol/ethanol) lin dpng CO v i xe gan miy con rat han che. Muc tieu chinh cfla d i tai nay nham danh gii anh hfldng cfla viic sfl dung nhien lieu khong dung chuan len dpng co va nhiet dp mpt so khu vflc cua xe gan miy. Kit qui nghien cflu co the lam co sd ho trp cho cac cd quan CO chflc ning thflc hien nhiim vu ting cfldng q u i n Iy v i Idem soit cua minh doi vdi chat Iflpng nhiin lieu xang cung nhfl dpng cd cic phflpng tiin hien nay tai Viet Nam.
2. THIET BI VA QUA TRINH THlT NGHIEM 2.1 Thiet bi thfl nghiem
Tat ca cac thfl nghiim dflpc thflc hien tren xe gan may tay ga (scooter) mdi. Xe thfl nghiem dfldc gin tren be thfl xe g i n may CO k h i nang mo phong tai trpng va toe dp giong nhfl khi xe chay trin dfldng.
Hmh 1: Sd do gdn cdc cdm bien nhiet do trin xe Honda Airblade trong qud trinh thd nghiem.
Tong c6ng 10 cam bien nhiet do dfldc bo tri tren xe de thu thap cic so lieu ve nhiit dp cic bp phan trong qua trinh xe van hanh. Sd do bo tri cac cim bien diidc bien dien trong hinh 1. Trong do, T l l i cam bien do nhiit dp nhdt boi trdn ("C); T2 la c i m bien do nhiit dp nfldc Iam m i t (°C); T3 l i cam bien do nhiit dp khi thii ("C); T4 Ii cam bien do nhiit dp trong thung chfla d6 C O ; T5 Ii c i m bien do nhiit dp phan duoi xe (°C); T6 la cam bien do nhiet dp bp day diin than xe (°C); T7 l i c i m bien do nhiet do mo bin sfldn (°C); T8 l i cim bien do nhiit dp khu vflc dpng co ("C);
T9 Ii cam bien do nhiet dp bp sac diin ("C) va TIO la cam biin do nhiet dp trong thung nhien hiu ("C). C i c c i m bien nhiit do dflpc ghi n h i n va phan tich nham danh gia anh hfldng khi sfl dung cic loai nhien lieu nay trin xe.
2.2 Nhien lieu thv£ nghiim Nhien lieu thfl nghiim dflpc chuan bi tai Trung tam Nghiin cflu Lpc - Hoa dau ph6i trpn va cung cap. Cac xing A95, A92, A83 (thfldng pham) dfldc tien hanh thfl nghiem dau tien lam CP sd de so sanh vdi cac mau nhien lieu dfldc pha trpn. Nhien lieu pha trpn la cic nhien lieu dUdc pha trpn theo ti li phin t r i m the tich gifla cic nhiin lieu xang A83, A92 vdi methanol/eth- anol. Thong tin ve nhien lieu thii nghiem trinh bay trong bang 1.
H!H
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2.3 Quy trinh thuT nghiein
Xe gan m i y dflpc lap dat co dinh t r i n be thfl, tii trong xe dflpc dit co dinh 140 kg (tfldng dfldng vdi 2 ngfldi). Xe dfldc chay theo quy trinh Japan 10-15 diem. Day l i quy trinh dung chay thfl nghiem d i n h gia tieu hao nhien lieu va khi thai tai Nhit.
0 too 200
Hinh 2: Chu trinh thd nghiim Japan 10-! 5.
Chu trinh thfl Japan 10-15 dflpc the hien trong hmh 2. Q u i trinh thfl dflpc tien h i n h lien tue. Cfl sau moi chu trinh, chung ta se ghi nhan cac gia tri nhiet dp va dung Iam cac so lieu de phan tich, so sanh.
3. KET QUA VA THAO LUAN
3.1 Nhiet do n h d t boi trdn ( T l ) , nfldc lam mat (T2) va khi thai dong ca xe
Hinh 3 trinh bay ket qua nhiit dp nhdt boi tron, nhiet dp nfldc lam mat va nhiet dp khi thai dpng co. Viic so sinh cac rhong so niy nhim danh gia tie dpng cua nhiin lieu lin dpng cp, xac dmh nguy ca qua nhiit cd the xay ra hay khong.
Hinh 3: Nhiit dd nhdt boi trdn. nUdc Idm mdt vd khi thdi dgng cd do dUdc ngay sau khi kit thitc chu trinh
thd Japan 10-1S.
Hinh 4: Nhiet do khu vUc khoang dgng cd, khu vUc thung do vd trong thung nhiin lieu xe do dUdc ngay
sau khi kit thuc chu trinh thd Japan 10-15.
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Theo ket qua hinh 3, sfl thay doi nhiit dp dpng CP xay ra khong nhieu khi sfl dung cac loai nhien lieu khic nhau. Tuy nhien, c i 3 do thi cho thay cung khuynh hfldng l i nhiet dp dpng ca khi sfl dung vdi nhiin lieu xing A83 Ii cao nhat.
Nhiet dp nhdt va nfldc khi sfl dung xang A83 cao bit thfldng co the giai thich do h i i n tflpng kich no cd the xay ra b i n trong dpng co dan den lam tang nhiit do cic chi tiet b i n trong dpng cd. Trong q u i trinh thfl nghiem, tai mpt so dieu kiin khi cho tai va tdc dp cao hon, nhiit dp nhdt lin tdi gan 100"C, nhiet dp khi thai dpng cd CO the lin tdi hdn 450*'C. Vdi nhiet dp khi thai cao, khi chay xe tren dfldng neu cd vii dinh v i o ong bo de dan den hiin tflpng bung chay xe bat thfldng.
3.2 Nhiet dp khoang dpng cd (T8), khoang dflng do (T4) va thung nhiin lieu (TIO)
Kit qua nhiet dp khu vflc dpng cp dflpc bieu dien trong do thi hinh 4. Nhiit dp khu vflc dpng cp khi sfl dung xing D3 cd xu hfldng cao nhit. Nhiet dp khu vflc dpng cp cd the len d i n hon 70 "C khi cho xe van h i n h lau d che dp tai cao.
Tai Viet Nam, mpt so xe tay ga dpng cP dflpc lam mat bang dung dich, khong can h i thong thong gio tfl nhiin lin khu vflc trong khoang dpng ca gia tang rat ldn v i truyen nhiet trflc tiep ra khung sfldng, thung chfla do hoac thung nhiin lieu dat phia tren. Viec truyen nhiit lau tfl khoang dpng cp vao thflng chfla do giy nguy hii'm neu nhfl trong khoang nay chfla cic vat lieu d i chiy. Hinh 4 cung cho ta thay nhiit dp trong khoang h i n h ly cua xe thfl nghiim. Trong mpt so trfldng hpp thfl nghiim, nhiet dp trong khoang chfla do co the len den hon 60 "C, dieu nay cd the gay tfl chay neu trong dd cd de cic thiet bi, hda chat (dien thoai di dpng, may tinh xich tay, nfldc hoa...). Ket hdp vdi nhieu yiu to khac, viec gia ting nhiet dp cao trong khoang chfla do cd the giai thich cho viec mpt so xe dang chay tfl boc chiy tfl khoang chfla do cfla xe gin may.
Kit qua nhiet dp trong thung n h i i n heu cung dflpc bieu dien trong dd thj hinh 4. Nhiit dp thung nhien lieu khi sfl dung xing D3 cd xu
hfldng cao nhat. Nhiit dp thimg nhien Hiu co thi l i n den hpn 50''C trong qua trinh thfl nghiim.
N h i i t dp niy, chflng td nhien lieu xang pha con de bay hoi hdn trong qua trinh sfl dung
Hinh 5: Nhiit do khu vUc duoi xe (T5). khu vUc bg ddy dien thdn xe (T6), khu vUc bo-bin sUdn (T7) vd khu vUc bg xac (T9) do dUdc ngay sau khi ket thuc chu
trinh thd Japan 10-15.
3.3 Nhiet do khu vtfc duoi xe (T5), khu viic bo day dien than xe (T6), khu vtic bd-bin sdisn (T7) v i khu vifc bo xac (T9)
Ket q u i nhiit dp phan duoi xe dfldc bieu dien trong do thi hinh 5. N h i i t dp phan duoi xe cua xing D3 co xu hudng cao nhat. Nhiet dp phan dudi xe cd the len den gan 50"C. Nhiet dp khu vflc
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NGHIEN COfU-TRAO 061
nay tang do sU truyen nhiet dp tfl khu vflc khoang dpng ca v i thung do cua xe truyen xudng.
Hinh 5 cdn cho ta thay kit qua do nhiet dp khu vflc bp d i y diin t h i n xe, nhiet dp bp diy dien thin xe cua xang D3 cd xu hUdng cao nhat. Nhiit dp bp day d i i n than xe cd the lin den gan 60°C.
Nhiit dp nay de lam bien tinh ldp bang keo bao ve neu nhfl viic dau noi khdng chit trong q u i trinh bio dfldng xe.
Kit qua nhiet do khu vflc bd-bin sfldn dflpc bieu dien trong do thi hinh 5. Nhiit dp bp md bin sfldn khi sfl dung xing D3 cd xu hfldng cao nhat. Nhiet dp mo bin sfldn cd the len den hdn 55°C. Ngoai ra, hinh 5 cdn cho ta thiy kit qua nhiit dp khu vflc bp sac. Nhiet dp bp sac diin khi sfl d\ing xang A83, D l v i D3 cd xu hfldng cao nhat. Nhiet dp bp sac diin cd the lin den hdn 70°C.
4. KET L U A N
Kit q u i nghien cflu d i n h gii i n h hfldng cua viic sfl dung cic loai nhiin lieu khac nhau trin xe gin miy cd the tdm tat nhfl sau:
- Viic pha nhiin h i u con (methanol/etha- nol) lim i n h hfldng den nhiit dpng cP, va mpt so
khu vflc trin xe gan miy.
- Dp hda hoi nhien lieu va nhiit dp trong thflng nhiin heu tang khi sfl dung xang co pha them con.
- Viec sfl dung nhiin lieu cd tri sd oc-tan thap gay ra sfl gia ting nhiet dp dpng cd mac du thfl nghiim vdi thdi gian ngin.
- Sfl truyin nhiet tfl khu vflc ddng ca vio khoang chfla do la Idn, cd the gay hien tfldng tfl phit chiy n i u nhfl khu vflc nay chfla cac vit lieu d l chiy.
Ldi cam dn:
De tii cd sfl phoi hpp thflc hiin cua Trung tam Cong nghi Lpc hda Dau, Trfldng Dai hpe Bich khoa TP. Ho Chi Minh, dfldi sfl dat hang cua Sd Khoa hpe vi Cdng nghi TP. Ho Chl Minh.
Tic gia chin thinh cam dn cic hpe viin Pham Quang Khii, Trfldng Hoai Linh, Nguyin Quoc Tan, Huynh Dinh Ngia da hd trp trong viec thfl nghiem. •
Ngiy nhan bii: 15/01/2013 Ngiy phan biin: 20/02/2013 NgUdi phan bien: TS. Nguyen Chi Tinh, Trfldng khoa Co diin, Trfldng Dai hpe Md - Dia Chat.
Tii H^u tham khao:
[1]. Sara McAllister, Jyh-Yuan Chen, A. Carlos Fernandez-Pello, Fundamentals of Combustion Process, Springer. ISBN 987-1-4419-7942-1.
[2]. Gary L.Borman, Kenneth W.Ragland, Combustion Engineering, McGraw-Hill. (ISBN 0-07- H5978-9).
[3]. Stephen R. Turns, An Introduction to Combustion, McGraw-Hill. (ISBN 0-07-116910-5).
[4]. Nguyen Ngpc Dung, P h i n tich d i n h gii nguyin nhan xe chiy tai Viet Nam, Tap chi Cd khi Viet Nam, s6 4, (04/2012).
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