Nhienlieu Thay The

8/3/2019 Nhienlieu Thay The

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Trang i

Ng Quang Tun 44DLOT n tt nghip

MC LC

LI NI U ................................................................................................................ 1

CHNG 1. TNG QUAN ..........................................................................................31.1.Nhin liu thay th .........................................................................................3

1.1.1 Cc ch tiu k thut ca nhin liu Diesel...............................................3

1.1.1.1 Nhit tr.............................................................................................3

1.1.1.2 nht .............................................................................................5

1.1.1.3 Tnh t bc chy ...............................................................................5

1.1.1.4 Hm lng tp cht ...........................................................................7

1.1.2 Nhin liu biodiesel .................................................................................9

1.1.2.1 Khi nim .........................................................................................9

1.1.2.2 Tnh hnh sn xut v s dng Diesel sinh hc t du thc vt ........10

1.1.2.3 c tnh ca biodiesel .....................................................................12

ESTER ............................................................................................................... 12

Metyl du ci ..............................................................................................12

1.1.2.4 Qu trnh iu ch biodiesel. ...........................................................13

1.1.3 Nhin liu LPG (Liquefied Petroleum Gases) ........................................15

1.1.3.1 Khi nim LPG ...............................................................................151.1.3.2 Tr lng LPG v th trng tiu th ..............................................16

1.1.3.3 c tnh nhin liu kh ha lng......................................................17

1.2.ng dng nhin liu thay th cho ng c diesel xe but Thnh Ph

Nha Trang..........................................................................................................22

1.2.1 Gii thiu chung v xe but Thnh Ph Nha Trang ............................22

1.2.1.1 S lc v xe but Thnh Ph Nha Trang ....................................22

1.2.1.2 Thng s k thut ca xe but Thnh Ph Nha Trang ..................23

1.2.2 c im k thut v cu to ca ng c D6BR s dng trn xe butThnh Ph Nha Trang .................................................................................29

1.2.2.1 Gii thiu chung v v tr ng c trn xe but................................29

1.2.2.2 c im k thut ca ng c.......................................................29

1.2.2.3 Nhm piston, xylanh, np xylanh ....................................................31

1.2.2.4. H thng nhin liu ........................................................................36

1.2.2.5 H thng np - x ............................................................................48


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CHNG 2. KH NNG S DNG NHIN LIU THAY TH CHO I

XE BUT THNH PH NHA TRANG ................................................................... 53

2.1. Phng n lp t h thng s dng nhin liu thay th cho ng cdiesel D6BR trn xe but thnh ph Nha Trang. ................................................53

2.1.1. H thng s dng nhin liu thay th n .............................................53

2.1.2 H thng s dng nhin liu thay th v diesel song song......................53

2.1.3 La chn gii php. ...............................................................................54

2.2 Gii php k thut ng c c th s dng nhin liu Biodiesel. .............54

2.2.1 Bnh sy s dng nc lm mt lm nng nhin liu ........................56

2.2.2 Bnh sy s dng ngun in mt chiu.................................................58

2.2.3 Bnh sy tn dng ngun nhit kh x ....................................................592.2.4 La chn ...............................................................................................60

2.2.5 S tng th h thng nhin liu s dng Biodiesel v Diesel song

song (H. 2-6 ) .................................................................................................60

2.3 Gii php k thut ng c c th s dng nhin liu LPG......................61

2.3.1 Gii php k thut ng c c th s dng LPG v diesel song

song................................................................................................................61

2.3.1.1 Gii php k thut h thng nhin liu diesel c kh nng phun

mi .............................................................................................................61

2.3.1.2 Gii php k thut lp t h thng cung cp LPG trn ng c......72

2.3.1.3 Gii php k thut lp t c cu hn ch tc ng c................88

2.3.2 S tng th h thng nhin liu LPG v Diesel song song.................93

CHNG 3. KT LUN V XUT KIN .................................................. 95

3.1 Kt lun. ......................................................................................................95

3.2 xut kin. .............................................................................................96

TI LIU THAM KHO ............................................................................................ 98


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LI NI U

Cng vi s pht trin mnh m ca nn kinh t, i sng nhn dn ngy

mt nng cao c v vt cht ln tinh thn. Song bn cnh t nc ta cng phi

i mt vi nhiu kh khn nh nhng nn kinh t ang pht trin khc, c bit l

vn nhim mi trng. Nhiu nh my, x nghip mc ln phc v i hi ca

qu trnh pht trin, ng thi x vo bu kh quyn mt lng kh thi khng nh.

i sng ngi dn c ci thin, kh nng mua sm cc vt dng t tin nh

t, xe mynm trong tm tay ca nhiu gia nh. Mt phng tin tham gia

giao thng ngy mt cao, bn cnh l s thiu ng b trong qu trnh quy hochgiao thng, vic qun l cht lng cc phng tin tham gia giao thng cn bung

lng. Nhng vn ny ang lm cho lng kh thi ca nghnh giao thng vn ti,

c bit trong lnh vc giao thng ng b x vo kh quyn ngy mt tng nhanh.

gii quyt vn ny cn phi c nhng chin lc di hn pht trin cc

phng tin giao thng cng cng nh ng st, tu in ngm, mng li xe

but,tm kim cc gii php k thut nhm nng cao qu trnh chy nhin liu v

s l kh thi, s dng cc phng tin dng nhin liu sch thay cho cc loi xedng nhin liu truyn thng xng, du nh hin nay.

i t m ngun nhin liu mi sch hn thay th cho nhin liu truyn thng

hin ang s dng khng ch gp phn lm gim nng cc cht c hi trong kh

thi, bn cnh n cn gp phn a dng ho cc ngun nhin liu, y li nguy

c cn kit ngun nhin liu truyn thng.

Thnh Ph Nha Trang cng nh cc thnh ph khc trong c nc, vn

gia tng cc phng tin giao thng c nhn nh t, xe my, nhim mi trng

ang lm au u cc nh qun l. c bit vi hng pht trin ca thnh ph l

tr thnh mt thnh ph du lch th vic kim sot cc cht c hi trong kh quyn

c mt bu khng kh trong lnh l vn sng cn. M rng mng li giao

thng cng cng c bit l i ng xe but, khuyn khch ngi dn gim bt

phng tin c nhn, s dng cc loi xe dng nhin liu sch.


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Hin nay trn th gii k thut chuyni xe dng nhin liu truyn thng

(xng, diesel) sang dng nhin liu thay th (LPG, Biodiesel, NGV, LNG) t

c nhiu thnh tu, c bit l k thut chuyn i ng c diesel sang dngnhin liu LPG c nhng bct ph mi. ng csau khi chuyni t thay i

kt cu ban u, gi thnh chuyn i r nhng vn p ng tt cc yu cu k

thut

Vi suy ngh t m kim ngun nhin liu mi thay th nhin liu truyn

thng, nhm lm cho mi trng thnh ph Nha Trang sch hn. Khuyn khch,

tuyn truyn ngi dn thnh ph ng h vic s dng nhin liu sch cho cc

phng tin c nhn ca m nh. T m rng m h nh pht trin rng ri trn c

nc. c s hng dn ca thy Phng Minh Lc, em xin ng gp mt phn

nh tng trn sm thnh hin thc vi ti: Nghin cu kh nng s

dng nhin liu thay th cho i xe but thnh ph Nha Trang.

Ni dung ca ti gm 3 chng:

Chng 1: Tng quan.

Chng 2: Kh nng s dng nhin liu thay th cho i xe but thnh phNha Trang.

Chng 3: Kt lun v sut kin.

Sau hn 3 thng n lc c gng, c s hng dn, gip tn t nh ca

thy Phng Minh Lc, Cng ty c phn t in my Nha Trang, qu thy c trong

Khoa C Kh, bn b trong qu trnh tm kim ti liu, ng gp kin. Em c

bn hon thnh ni dung v trnh by trong lun vn ny.

Do trnh v thi gian c hn, mt khc v y l ln u tin thc hin

c lp mt cng tr nh mang tnh cht nghin cu khoa hc nn khng th trnh

khi nhng thiu st. Em rt mong nhn c s thng cm, ch dy, gp ca qu

thy c v bn b b sung cho ti ny c hon thin hn.

Em xin chn thnh cm n.

Nha Trang, ngy 20 thng 11 nm 2007

SVTH: Ng Quang Tun


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CHNG 1. TNG QUAN

1.1.Nhin liu thay th

1.1.1 Cc ch tiu k thut ca nhin liu Diesel.

Cc ch tiu k thut quan trng nht ca nhin liu diesel bao gm: nhit tr,

tnh t bc chy,hm lng tp cht v nht.

1.1.1.1 Nhit tr

Nhit tr (H) l lng nhit nng to ra khi t chy hon ton mt n v

khi lng hoc mt n v th tch nhin liu. nhit tr ca nhin liu lng v rn

thng tnh bng kJ/kg, ca nhin liu kh-kJ/m

3

hoc kJ/kmol. Anh v M, nhittr c tnh bng n v Btu/lb ( British thermal unit/pound ) hoc Btu/ft3 ( British

thermal unit/foot3 ).

Nhit tr l mt ch tiu cht lng c bn ca tt c cc loi nhin liu .

nhit tr c th c xc nh bng nhit lng k ng tch (nhit lng k kiu

bom) hoc nhit lng k ng p bng cch t chy mt lng xc nh mu th

ri o nhit lng to ra v tnh ton nhit tr. Khi tnh ton, chng ta thng ly

nhit tr t cc bng s liu c sn. trnh nhm ln, cn phn bit cc khi nimnhit tr di y:

Nhit tr ng p (Hp)- Nhit lng thu c khi t chy hon ton mt

n v s lng nhin liu sau khi lm lnh sn phm chy n nhit bng nhit

ca hn hp trc lc t chy trong iu kin p sut ca sn phm chy

c lm lnh bng p sut ca kh hn hp trc lc t chy.

Phng trnh cn bng nng lng nhit lng k ng p:

Ec + Uf+ p.Vf + Ua + p.Va = Up + p.Vp + Hp

hoc Ec + Um + p.Vm = Up + p.Vp +Hp

Ec = (Hp + Ip Im)T

Nhit tr ng tch (HV)- nhit lng thu c khi t chy hon ton mt

n v s lng nhin liu sau khi lm lnh sn phm chy n nhit bng

nhit ca hn hp trc lc t chy trong iu kin khng thay i th tch ca

sn phm chy v hn hp kh trc lc t chy.


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Phng trnh cn bng nng lng nhit k ng tch :

Ec + Um = Up + HV

Ec =(HV + Up Um)T

Ec- ho nng ca nhin liu

Uf, Ua, Um, Up - ni nng ca nhin liu, khng kh, hn hp chy v sn

phm chy, tng ng,

Im, Ip enthalpy ca hn hp chy v sn phm chy,

Hp, HV- nhit tr ng p v nhit tr ng tch.

Nhit tr ng p c ngha thc t trong tnh ton cc thit b ng lc, v

sn phm chy thng c thi ra kh quyn c p sut v nhit bng p sut

v nhit ca nhin liu v khng kh trc lc i vo thit b. V vy, nu trong

cc bang s liu cho nhit tr ng tch hoc nu xc nh nhit tr bng nhit lng

k ng tch th phi i sang nhit tr ng p. C th s dng cng thc sau y:

Hp = Hv + 10-3 pm(Vm Vp)

Trong : Hp, Hv - nhit tr ng p v nhit ng tch, [kJ/kg],

Pm- p sut ca hn hp trc khi t chy, [N/m2

]Vm, Vp- th tch ca hn hp trc lc t chy v ca sn phm chy

c lm lnh p sut pmng vi 1 n v s lng nhin liu.

i vi nhin liu lng gc du m: Hv H02,1 .

Nhit tr cao (Hc)- nhit lng thu c khi t chy hon ton mt n v s

lng nhin liu, bao gm c lng nhit to ra do s ngng t ca hi nc c

trong sn phm chy khi ta lm lnh n n nhit bng nhit ban u.

Nhit tr thp(HT)- nhit lng thu c trong trng hp nc c trong sn

phm chy vn trng thi hi. Nh vy nhit tr thp nh hn nhit tr cao mt

lng bng nhit n ho hi ca nc c trong sn phm chy.

-i vi nhin liu lng:

HT = HC r.(9h + w)Trong : HT, HC - nhit tr thp v nhit tr cao, [kJ/kg],

r- nhit n ho hi ca 1 kg nc, r =2.512 kJ/kg


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9h- lng hi nc c hnh thnh khi t chy h kg hydrogen c trong 1

kg nhin liu,

w- lng nc c trong 1 kg nhin liu.1.1.1.2 nht

nht- cn gi l ma st ni, l mt tnh cht ca cht lng c trng cho

lc ma st chng li s chuyn dch tng i ca cc lp cht lng cnh nhau di

tc dng ca ngoi lc.

nht ca nhin liu diesel c nh hng ch yu n cht lng qu trnh

phun nhin liu. nht qu cao lm cho cc tia nhin liu kh phn tn thnh cc

ht nh v c th bm trn thnh xylanh. Ngc li, nht qu thp li lm cho

cc tia nhin liu qu ngn, khng bao trm ht khng gian ca bung t. C hai

trng hp trn u dn n cht lng qu trnh to hn hp chy khng cao, lm

tng lng nhin liu chy rt v chy khng hon ton. Ngoi ra, nht ca

nhin liu qu thp c th nh hng xu n cht lng nh lng ca h thng

phun do lm tng mc r r ti cc cp siu chnh xc ca bm cao p v vi

phun, ng thi tng mc mi mn ca cc chi tit chuyn ng thuc h thngnhin liu .

Mc d khng phi l mt ch tiu k thut c nh hng quyt nh n

cht lng hot ng ca ng c, nhng ngi ta thng cn c vo nht

phn loi du diesel nng.S d nh vy l v:

- nht ln l mt i lng d xc nh.

- nht c lin quan n nhiu tnh cht khc ca du diesel. V d: nu

nhin liu nng c nht di 3500 sec Redwood, th s cetane thng cao hn

25 v lng tp cht cng thng thp hn mc quy nh.

1.1.1.3 Tnh t bc chy

Tnh t bc chy ca nhin liu l tnh cht lin quan n kh nng t pht

ho khi hn hp nhin liu khng kh chu tc dng ca p sut v nhit

ln.


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nh lng tnh t bc chy ca nhin liu, c th s dng cc i lng

di y:

Thi gian chm chy(ti)- Nhin liu c tnh t bc chy cng cao th thi

gian chm chy cng ngn, v ngc li. Thi gian chm chy l i lng phn

nh tnh t bc chy ca nhin liu diesel theo cch m chng ta mong mun nht,

bi v n c nh hng mnh v trc tip n ton b din bin v cht lng ca

qu trnh chy ng c diesel. Tuy nhin, thi gian chm chy ca nhin liu

diesel ng c thc t ch ko di t vi phn vn n vi phn ngn mt giy. o

trc tip mt khong thi gian ngn nh vy l mt vic rt kh, cho nn ngi ta

s dng mt s i lng khc nh gi tnh t bc chy trn c s mt s

tnh cht l-ho ca nhin liu c lin quan mt thit vi thi gian chm chy, hoc

so snh tnh t bc chy ca mu th v nhin liu chun.

Hng s nht-t trng ( Viscosity Gravity Number VG ) l mt thng

s c tnh ton trn c s nht v t trng ca du diesel. Tu thuc vo n

v ca nht, n v ca t trng v quan im ca tc gi, cng thc tnh c

nhng dng khc nhau. Ch s diesel ( Diesel Index DI ) l thng s c tnh ton trn c st

trng v im aniline ca nhin liu

Bi v nht, t trng v im aniline u l nhng i lng c quan h

cht ch vi thnh phn ho hc ca du diesel xt t hm lng cc nhm

hydrocarbon, nn hng s nht-t trng v ch s diesel s phn nh tnh t bc

chy ca nhin liu. Hng s nht-t trng cng nh th thi gian chm chy

cng ngn, tnh t bc chy cng cao; cn ch s diesel cng nh th thi gian chm

chy cng di.

S cetane- ( Cetane Number CN ) l i lng nh gi tnh t bc chy

ca nhin liu bng cch so snh vi nhin liu chun. V tr s, l s phn trm

th tch ca cht n-cetane (C6H34) c trong hn hp vi cht aphthalenmethy ln

(C10H7CH3) nu hn hp ny tng ng vi nhin liu th nghim v tnh t bc

chy.


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Phng php xc nh s cetane c p dng ph bin hin nay l so snh

t s nn ti hn ( t s nn ti hn l t s nn, ti nhin liu s pht ho) ca

nhin liu th nghim v ca nhin liu chun trn mt loi ng c tiu chun hohot ng mt ch quy c.

Nhin liu chun l hn hp vi nhng t l th tch khc nhau ca n-C16H34

v 3710 CHHC .n-C16H34l mt hydrocarbon loi parafin thng c tnh t bc

chy rt cao, ngi ta quy c s cetane ca n bng 100; cn 3710 CHHC l

mt hydrocarbon thm, cha mt nhm methyl trn ln vi cc nguyn t

hydrogen , kh t bc chy, c s cetane quy c bng 0.

1.1.1.4 Hm lng tp cht

Du diesel, c bit l du cn, thng cha mt lng ng k tp cht c

ngun gc t du m(v d:S, V, Na, P, ) hoc t mi trng thm nhp vo

trong qu trnh ch bin,vn chuyn, bo qun v phn phi (v d: nc, t,

ct,).

Tp cht c hc- Tp cht c hc trong nhin liu c nh hng n h

thng phun nhin liu ca ng c diesel mt cch trc tip v nghim trng hn sovi trng hp ca ng c xng.Trong h thng phun nhin liu ca ng c

diesel c nhng chi tit c ch to vi chnh xc rt cao, nh cp piston-

xylanh ca bm cao p v u phun ca vi phun. Khe h gia cc cp chi tit ni

trn c tr s trung bnh khong 0,003 mm v s c mt ca vt cng vi kch thc

vi phn ngn mm cng c th lm h thng phun nhin liu b h hng rt nhanh.

Chnh v vy, h thng lc nhin liu ca ng c diesel thng phc tp hn ng

thi vic bo tr chng cng c nhng yu cu kht khe hn. i vi du cn c

nht v hm lng tp cht c hc cao, ng c cn phi c trang b h thng x

l nhin liu c chc nng sy nng v loi b nhng tp cht c kch thc ln

trc khi nhin liu c a n cc b lc thng dng.

Lu hunh(S)- S c trong nhin liu tn ti di dng t do hoc hp cht,

nh mercaptan, sulffide,vv. D tn ti dng no, S u c tc ng n mn

nhng mc khc nhau.


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- Mercaptan c kh nng tc dng ln nhiu loai kim loai, nh ng (cu),

km(zn), cadmum(cd), v s to thnh cc hp cht ho hc phc tp, kh tan. Cc

hp cht ny c th kt ta trn cc chi tit ca h thng nhin liu lm nh hng

xu n hot ng ca ng c.

- Lu hunh t do(S) s c t chy thnh SO2. Mt phn SO2 b oxy ho

thnh SO3 di tc dng xc tc ca oxyt st(Fe2O3) v mt s cht khc c trong

nhin liu. Sau , SO3 kt hp vi hi nc to thnh axit phosphoric(H2SO4)

theo cc phn ng:

S + O2

SO2

2SO2+ O2 2SO3

SO3 + H2O H2SO4

Trong iu kin nhit cao, axit phosphoric tn ti trng thi hi cng

vi hi nc v cc cht khc ca kh thi. Khi nhit ca kh thi gim xung,

hi axit c th ngng t v c tc ng n mn mnh


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1.1.2 Nhin liu biodiesel

1.1.2.1 Khi nim

Biodisel l nhng mono ankyl ester, n l sn phm ca qu tr nh ester haca cc axt hu c c nhiu trong du m ng thc vt. N l nhin liu c th

thay th cho du diesel truyn thng, s dng trong ng c t trong.

Di tc dng ca cht xc tc, du thc vt + methanol hoc ethanol cho

sn phm ester + glycerine + axit bo (ester ha du thc vt bng ethanol kh hn

bng methanol).

V d: 1.05 tn du ci + 0.11 tn methanol cho ra 1 tn ester + 0.1 tn

glycerine + 0.025 tn axit bo.

Thng thng biodiesel c s dng dng nguyn cht hay dng hn hp

vi du diesel. V d nh B20 l hn hp gm 20% biodiesel v 80% diesel c

ngun gc du m.

H. 1-1. Xe but s dng nhin liu biodiesel (u nnh).


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H. 1-2. Biodiesel th nghim trn t M

1.1.2.2 Tnh hnh sn xut v s dng Diesel sinh hc t du thc vt

1.1.2.2.1 Tnh hnh th gii:

Vn s dng du thc vt lm nhin liu cho ng c diesel c

chnh Rudolf Diesel- ngi pht minh ra loi ng c ny dng t cch y hn

mt trm nm (du lc). Sau y, nhin liu ha thch qu nhiu v r nn ngi ta

lng qun n, nhng t nhng nm 80 ca th k trc tr li y, du m c

du hiu cn kit, gi c tng chng mt buc th gii phi t li vn ny. i

tin phong c l phi k n ngi c, nm 1988, cc cng ty ho cht ca c

tinh luyn loi du diesel sinh hc t ht Ci du, loidu ny khng nhng githnh thp, m cn c th trng c nguyn liu, m bo chy ht, hm lng

cc-bon ca kh thi -t thp hn 50% so vi du diesel truyn thng . Hin nay,

15% trm xng ca c c cung cp du diesel sinh hc, n tr thnh ngun

nhin liu chnh cho cc xe ch hng ng di v xe but. Hng Shell trong nm

nay cng c k hoch u t 400 triu Euro vo min Bc nc c xy

dng thm mt nh my sn xut loi sn phm ny, d kin n nm 2008, sn


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lng s t ti 200 triu lt. Ngoi ra cc nc trng nhiu cy c du cng vo

cuc: Hn quc s bn du diesel sinh hc (biodiesel) cho cc phng tin t nhn

t thng 7/2006. Loi biodiesel ny gm diesel v 5% du ht Ci. Hn quc angcn nhc s dng loi biodiesel cha 20% du ht Ci trong tng lai; Malaixia l

nc ng u th gii v sn xut du C, vi sn lng 13,9 triu tn (nm

2004), ch bin du diesel sinh hc t ngun nguyn liu di do ny s gp phn

p ng nhu cu nhin liu trong nc v xut khu; Nht bn v Indonnesia: Mt

d n c quan tm nht l vic pht trin nhin liu biodiesel (du diesel sinh

hc) s dng cy c dujarak ( Jatropha curcas L) vn rt ph bin

Indonesia.Hin Indonesia c hng nghn hcta t c th dng pht trin loi

nng lng xanh ny; Trung quc: n 2010 sn xut 1triu tn, nm 2020 s sn

xut 9 triu tn du diesel sinh hc t cy Hong lin v cy ay. 1.1.2.2.2 Tnh hnh trong nc :

Theo ngh ca B Cng nghip v Vn phng Cng ty Sojitz ti H Ni,

ngy 03 thng 8 nm 2005, B Ti nguyn v Mi trng, vi t cch l C quan

u mi ca Chnh ph Vit Nam tham gia v thc hin Ngh nh th Kyoto xc nhn PIN pht trin du Da diesel sinh hc theo CDM ti tnh Bnh nh.

Nhm nghin cu do PGS.TS H Sn Lm - phn vin trng Phn vin

Khoa hc vt liu TP.HCM thuc Vin Khoa hc v cng ngh VN - ch tr khng

nh c kh nng nghin cu sn xut du diesel sinh hc (biodiesel) t du thc

vt ca Vit nam. PGS.TS H Sn Lm cho bit nhm nghin cu hp tc vi

Vin Ha k thut H Tng hp Jena (c) phn tch thnh phn, tnh cht cc

mu du diesel sinh hc do nhm iu ch. Kt qu cho thy cc mu du diesel

sinh hc t du thc vt VN t tiu chun chu u v biodiesel.

T thng 8/2006, h thng thit b sn xut nhin liu diesel sinh hc

(biodiesel) t du n ph thi vi cng sut 2 tn/ngy s c trin khai ti cng ty

Ph Xng, qun Th c, TP.HCM. D n sn xut du biodiesel t du n ph

thi ti TP.HCM c ngun vn u t khong 9,69 t ng, trong c 1,5 t ng

vay t ngun vn ngn sch Nh nc.


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1.1.2.3 c tnh ca biodiesel

Tnh cht vt l ca biodiesel tng t nh diesel nhng tt hn diesel v

mt cht thi.Biodiesel khc phc c nhng nhc im ca du thc vt nh nht

qu ln (cao gp 6 14 ln diesel), ch s Cetan thp, d b trng hp.

Cc loi biodiesel u c t l % trng lng oxy kh ln, y l iu m du

diesel khng c.

Bng 1-1.Tnh cht l ha c bn ca mt s biodiesel [ 7 ]

ESTER

Khilngring

(g/cm3)

nht( 200C)( cSt )

imc(0C)

imchp la

(0C)

Nhit tr (MJ/kg)(kCal/kg)

Metyl du ci 0.88 7.09 -5 171 37.70 (9020)

Oleate ca methylk thut

0.88 7.4 -14 37.37 (8940)

Methyl du da 0.886 5.3 -2 93 37.83 (9050)

Du diesel 0.836 5.3 -2 40 43.80 (10478)

Bng 1-2. Hm lng cn v ch s Cetan ca mt s cht [ 7 ]

ESTER Cn Ch s Cetan

Metyl du ci 1.2 43

Oleate ca methyl k thut 0.8 54

Methyl du da 0.7 43Du diesel


15/100

- 13 -


Bng 1-3. So snh mt s tnh cht vt l ca hn hp nhin liu ester du ci ha

vi diesel cc t l % khc nhau [ 7 ]

Ch tiu Diesel B20 B30 B40 B50 B75 B100

Ch s Cetan 52.0 52.0 52.4 52.8 53.2 54.1 54.1

Khi lng ring

(g/cm3)0.840 0.846 0.851 0.856 0.861 0.873 0.884

nht

(mm2/s)4.8 4.9 5.2 5.5 5.8 6.4 13.1

im nng ch(0C)

-9 -9 -9 -9 -9 -9 -12

im c

(0C)-6 -6 -5 -5 -5 -5 -5

%O2 theo

khi lng0.00 2.35 3.30 4.60 5.95 8.86 10.70

Nhit tr

(kJ/kg)43800 41983 41443 40903 40600 38664 37370

1.1.2.4 Qu trnh iu ch biodiesel.Nhin liu biodiesel c lm t du thc vt, m ng vt cn mi hay

qua s dng. Nguyn tc ca qu tr nh: du m tc dng vi cn methanol hoc

ethanol to ra ester. Cc ester ny chnh l biodiesel. Sn phm ph ca qu trnh

ny l glycerin s dng trong ngnh dc v m phm.

Hin nay biodiesel c sn xut t qu tr nh chuyn ha ester. Du thc

vt, m ng vt sau khi lc c thy phn trong mi trng kim tch axit bo

t do. Sau uc trn vi cn (thng l methanol) v cht xc tc Natri hay KaliHidroxit triglyceride phn ng to ra ester v glycerin. Cui cng l giai on

tch v lm sch.


16/100

- 14 -


Cc phn ng ha hc:

2 1

OH2

2 3

CH COOR

|CHCOOR|CH COOR

2

2

CH OH

|CHOH|CH OH

+

1

2

3

R COOH

R COOH

R COOH

NaOH(KOH)3 3RCOOH CH OH RCOOCH

RCOOCH3 c gi l biodiesel.

S sn xut biodiesel:

T nhng iu trnh by trn ta thy biodiesel c cc c tnh gn ging nh

diesel, thch hp s dng trn ng c t trong v vic t m kim loi du thc vt

p ng c tiu chun lm nhin liu cho ng c t trong, khng cnh tranh

Du m

Thy phntrongmi trng kim

Este ho bng methanolhoc ethanol

Tch

Lm sch

Biodiesel

Lc

Cht xc tc


17/100

- 15 -


vi thc phm, c thu li c cao l iu rt cn lm. Trong cc loi cy ly du

c chit sut ln v c sn lng phong ph, thch hp vi iu kin kh hu min

nam nc ta phi k n cy da. V cy da chng ta cha c mt iu tra c bny nhng ng v mt k thut th n l mt ngun nhin liu tt cho ng c

t trong: nhit tr cao, nht thp nht trong cc loi du thc vt, ch s Cetan

cao gn bng diesel, l nhin liu linh ng c th pha vi diesel bt c t l no. .

. Do n l mt trong nhng ng c vin sng gi cho vic nghin cu v ch

bin lm nhin liu biodiesel cho ng c t trong. Mt khc theo gio s Chu

Phm Ngc Sn th cy c du (c tnh cht gn nh cy da) l mt cy cng

nghip rt ng lu , sn lng cao hn da nhiu, khong 3.5 tn/ha, thu li trn

mi hecta l 2505 la. Vic nghin cu tt cy da lm nhin liu cho ng c s

to iu kin cho vic nghin cu cy c du.

1.1.3 Nhin liu LPG (Liquefied Petroleum Gases)

1.1.3.1 Khi nim LPG

Nhin liu kh ho lng(LPG:kh du m ho lng) c thnh phn c bn l

propane (C3H8) v butane (C4H10), ngoi ra kh ho lng cn cha mt lng nhcc hydrocarbon khc nh: ethane (C2H6), pentane (C5H10), ethylene (C2H4),

propylene (C3H6), buthylene (C4H8) v cc ng phn (isomer) ca chng.

Loi nhin liu ny c pht trin v thng mi ho t nhng nm 1950.

My thp k qua chng c dng ch yu cho cng nghip nh cng nghip thu

tinh, gm v sinh nhit gia dng. Kh ho lng cn c phn tch thnh cc cu

t ring bit lm nguyn liu cho nhiu ngnh cng nghip khc nh sn xut

cao su nhn to, vt liu tng hp, phm mu, dc liu, v.v . Vic nghin cu s

dng chng cho ng c t trong trn phng tin giao thng vn ti bt u

trong nhng nm gn y.Tuy vic p dng loi nhin liu trn t cn nhng thit

b cng knh hn nhin liu lng nhng n cho php gim c mc pht

nhim v chnh l im m cc nh ch to t quan tm nht hin nay. Khi s

dng chy ng c t, kh ho lng thng c cha trong b nh di p sut

khong 16 bar.


18/100

- 16 -


1.1.3.2 Tr lng LPG v th trng tiu th

L sn phm trung gian gia kh thin nhin v du th, nhin liu kh ho

lng c th thu c t cng on lc du hoc lm tinh khit kh thin nhin. Vvy, ngun gc kh ho lng ph thuc vo xut x nhin liu. Ni chung trn th

gii c khong 40% LPG thu c t qu trnh lc du th.

Sn lng kh ho lng trn th gii nm 1995 l 130 triu tn, chim 2%

tng nng lng tiu th di cc dng khc nhau. Ngi ta d kin trong nhng

nm u ca th k 21, tng sn lng LPG trn th gii s t khong 200 triu

tn/nm

Bng 1-4. Sn lng v tiu th kh ho lng ti chu [ 5 ]

( n v tnh: 1000 tn. Theo Asia LPG Seminar organized by

LPG Center of Japan, Tokyo 2/1998 )

1996 2000 2010Nc Sn

lngTiu th

Snlng

Tiu th Sn lng Tiu th

Indonesia 3228 715 3432 1154 2400 2886

China - 5758 - 9000 - 27000

Japan 4537 19710 4686 19959 4520 21600

Korea 1461 5761 2300 6323 2803 9448

Malaysia 1499 1392 3435 2226 3521 3718

Philippines 429 811 601 1414 1359 3497

Taiwan 700 1410 1130 1500 1750 1800

Thailand 1959 1829 2979 2240 3755 3531

India 3356 4198 3805 8439 10000 15000

Vietnam 0 86 340 224 840 527

Phn ln lng kh ho lng thu c hin nay c s dng lm ngun cht

t sinh nhit gia dng hay cng nghip. Lng kh ho lng lm nhin liu cho

t ng trng hin ch chim mt t l khim tn: 1% Php, 3% M, 8%

Nht


19/100

- 17 -


Tuy nhin mt s nc c chnh sch khuyn khch s dng LPG lm

nhin liu cho t nhm mc ch gim nhim mi trng th t l ny rt ng

k, chng hn nh H Lan, (42%)Cc s liu trn cha k nhng ng c trncc t chuyn dng s dng LPG( chng hn t chy trong sn bay, xe nng

chuyn , my mc nng nghip).

T l tiu th LPG vi nc tiu biu:

Php: Nhin liu(1%); Cng nghip(15%); Nng nghip(17%); Gia

dng(67%)

H Lan: Nhin liu(42%); Cng nghip(24%); Nng nghip(14%); Gia

dng(20%)

S pht trin t dng LPG ph thuc vo ch trng ca mi quc gia, c

bit l ph thuc vo chnh sch bo v mi trng. S khuyn khch s dng t

LPG th hin qua chnh sch thu u i ca mi quc gia i vi loi nhin liu

ny.

T l t s dng LPG mt s nc nh: H Lan(8,7%); Hn Quc(7,6%);

(4,4%); Nht(0,7%); M(0,4%); Php(0,1%). mt s nc Chu , Hn Quc v Nht Bn chng hn. gim nhim

mi trng th, chnh ph cc nc ny khuyn khch, tin ti buc taxi phi

dng nhin liu kh ha lng. Hin nay ton b taxi Hn Quc u dng loi nhin

liu ny. [2 ]

1.1.3.3 c tnh nhin liu kh ha lng

1.1.3.3.1 Thnh phn ho hc

Theo tiu chun Chu u, nhin liu kh ha lng phi c t 19 n 50%

hydrocabure C3 ( propane v propylene). Chu , thnh phn nhin liu kh ha

lng kh n nh, cha ch yu l hydrocarbure C4, chng hn nh Hn Quc ch

c butane l kh ha lng c s dng chnh thc. Ngc li M th ch c

hydrocarbure C3 c s dng.

Hin nay trn th trng nc ta c sn phm LPG ca nhiu cng ty kinh

doanh khc nhau, thnh phn ca propane v butane trong hn hp cng khc nhau:


20/100

- 18 -


LPG ca Elf Gas Si Gn c t l Propane / Butane l 20/80, ca Petrolimex l

30/70, ca Si Gn Petro l 50/50.

Nht, cung cp cho dn c LPG di dng 100% Propane v thi tit lnh,Propane d bc hi hn Butane, cn cung cp cho cng nghip di dng 100%

Butane v d vn chuyn, tn cha v trong iu kin sn xut d trang b cc thit

b u un nng LPG bc hi hon ton khi s dng.

Bng 1-5. c tnh l ho ca cc loi LPG thng phm.

Loi LPG

c tnh 100% Propane(Propa Gas) 100% Butane(Buta Gas)

Hn hp Butane Propane 50/50(Sai Gn Petro)

T trng [ g/cm3 ] (150C) 0,507 0,580 0,541

p sut hi [ kg/cm2 ] (400C) 13,5 3,2 9,2

Thnh phn:C2 (Etane)C3 (Propane)C4 (Butane)C5 (Pentane)

1,796,21,50,0

0,00,4

99,40,2

0,051,547,51,0

Nhit chy [ kcal/kg] 11.070 10.920 10.980

Nhit lng to ra khi t chy (nhit chy) ca Propane 11.070 kcal/kg,

trong khi Butane l 10.920 kcal/kg. Mt khc p sut hi to ra 200C ca

Propane l 13,5kG/cm2, ca butane l 3,2kG/cm2. Qua ta thy LPG cng nhiu

Propane th nhit chy c cao hn mt t v s dng c trit v bc hi hon

ton nhit mi trng. Ngc li, LPG c nhiu Butane th bnh cha khng

cn c p lc cao v p sut hi khng ln nhit mi trng nhng khng s

dng c trit nu nhit mi trng thp. Ni chung, LPG c th c thnh

phn Propane v Butane khc nhau, nhng cht lng ca LPG khng c g khc

nhau ng k.

Cng cn nhn mnh thm rng, nhin liu kh ha lng cha rt t lu

hunh. Thng n ch cha t 40 60ppm, thp hn rt nhiu so vi tiu chun


21/100

- 19 -


Cng ng Chu u(200ppm). Do , ng c dng LPG pht rt t cc cht

nhim gc lu hunh v hiu qu ca b lc xc tc c ci thin.

1.1.3.3.2 L tnhNhin liu kh ha lng c nhit tr ring theo khi lng (PCIm) cao, cao

hn c xng hay du diesel. Tuy nhin do khi lng ring ca n thp, nhit tr

ring theo th tch (PCI) thp hn nhin liu lng.

LPG c th c ho lng nhit bnh thng bng cch gia tng p sut

va phi hoc p sut b nh thng bng cch s dng k thut lm lnh lm

gim nhit .

Bng 1-6. So snh LPG v cc loi nhin liu c in [ 2 ]

H. 1-3. So snh th tch cha nhin liu ca cc loi nhin liu khc nhau

cho cng tng s nng lng pht ra

Thng s c trng Eurosuper DieselPropane

thng miButane

thng miLPG

Khi lng ring(kg/dm3)

0,725-0,780 0,820-0,860 0,51 0,58 0,51-0,58

Nhit tr thp PCI

-theo khi lng(MJ/kg) 42,7 42,6 46,0 45,6 45,8

-theo th tch(MJ/dm3)

32,0 35,8 23,5 26,4 25,0


22/100

- 20 -


Bng 1-7. So snh LPG vi xng, du diesel [ 11 ]

(Theo Bch Khoa Ton th M Wikipedia )

1.1.3.3.3 Ch s Octane

Nhin liu kh ha lng c c trng bi ch s octane nghin cu (RON)

cao, c th d dng t n 98.

Trong thc t, ngi ta xc nh ch s octane (Octane Number ON) cahn hp kh ho lng bng cng thc:

ONhh = V1.ON1 + V2.ON2 ++ Vn.ONn

Trong :

ON1,ON2,ONn l s octane ca hp phn ring bit ca hn hp.

V1, V2,,Vn l % th tch ca cc hp phn ring bit.

Bng di gii thiu RON ca cc loi kh khc nhau. Ch s octane ng c

(MON) ca LPG cng cao hn xng.

Bng 1-8. Ch s octane ca mt s cht

Cht RON MON

PropanePropenen-ButaneIsobutaneButene1

Butene2

>100102

95>100(98)

100

10085929980

83


23/100

- 21 -


1.1.3.3.4 Ch tiu cht lng ca LPG

Bng 1-9. Ch tiu cht lng LPG ca PETROLIMEX [ 5 ]

Ch tiu cht lng Mc qui nh Phng php th

1. t khi-d4

15 max

d@600F max

0,5531

0,5533

ASTM D.1657

2. p xut hi bo ho 37,8 0C, [kPa] 480-820 ASTM D2598

3.Thnh phn, [ % mol]

-Ethane

-Propane

-Butane

0.2 - 1.0

30 - 40

60 - 70

ASTM D.2163

4. Nhit tr, [kcal/kg] 40000 - 55000 ASTM D.2598

5. Hm lng sulphur, [ppm] max 170 ASTM D.2784

6. Hm lng hydrogen sulfide, [ppm] Negative ASTM D.2420

7. Nc t do Khng

8. n mn ng 37,8 0C No.1 ASTM D.1838

Bng 1-10. LPG ca Nga theo tiu chun 2044-75 [ 5 ]

Ch tiu Mc qui nh

1.Thnh phn-Tng lng hydrocarbon c C 2, max

-Tng lng propane, propylene,max/min-Tng lng butane v butylene, max/min

475/-

-/20

634/-

-/60

6-/34

60/-

2. Phn lng ( C5 ) 200C, [%vol] 1 2 2

3. p sut hi bo ho 45/-200C, [kgf/cm2 ], max 16/1,6 16/- 16/-4. Hm lng H2S, [g /100m

3 kh ] 0,015 0,015 0,015

5. Hm lng lu hunh tng , [%wt] 5 5 5

6. Hm lng nhn bit mi trong khng kh, [% vol] 0,5 0,4 0,3

7. Nc t do v kim Khng Khng Khng

- Hn hp propane butane k thut ma ng

- Hn hp propane butane k thut ma h

- Butane k thut


24/100

- 22 -


1.2.ng dng nhin liu thay th cho ng cdiesel xe but Thnh Ph Nha

Trang

1.2.1 Gii thiu chung v xe but Thnh Ph Nha Trang1.2.1.1 S lc v xe but Thnh Ph Nha Trang

Xe but Thnh Ph Nha Trang do Vit Nam v Hn Quc sn xut. ng

c v gm xe l ca hng Huyndai-Hn Quc sn xut, phn cn li do Cng Ty

t 1-5 sn xut.

Xe but l loi xe khch c chung nhn hiu Transinco, chng gp phn rt

quan trng vo vic vn chuyn hnh khch i li trong Thnh Ph Nha Trang v

cc vng ven thnh ph. Xe but gp phn gim lu lng cc phng tin c nhn

lu thng trong thnh ph t lm gim nhim, tai nn, n tc giao thng, to v

p vn minh cho th.

Xe but Thnh Ph Nha Trang mang tnh hin i, an ton, thm m . Xe

c tnh nng ng lc hc cao, tc chung bnh cao, khi ng d dng, h thng

phanh, h thng li hin i, tnh an ton cao. Vt liu ch to cc chi tit c bn,

chng mn, chng g tt, ph hp vi kh hu bin ca thnh ph. v xe c kt cuv mu sc p to v p m quan cho th

H. 1-4. Xe but Nha Trang phc v ch khch


25/100

- 23 -


1.2.1.2 Thng s k thut ca xe but Thnh Ph Nha Trang

1.2.1.2.1 Loi, Kch thc v trng lng ca xe but

Th t Tn gi n v Thng s v c tnh

(1) (2) (3) (4)

1 Loi t Khch, c trung

2 Chiu di tng th mm 8480

3 Chiu rng tng th mm 2290

4 Chiu cao tng th mm 3015

5 Khong cch trc trc mm 1910

6 Khong cch trc sau mm 1740

7 Vt bnh c s mm 4000

8 Trng lng tnh kg 5950

9 Trng lng ton ti kg 7875

10 Cng thc bnh xe 6x4

11 S ch ngi ch 55

1.2.1.2.2 ng c t

(1) (2) (3) (4)

1 Kiu ng c D6BR(diesel)2 Loi ng c 4 k,tng p, 6 xylanh

b tr 1 hng thngng

3 ng knh v hnh trnh piston mm 118x115

4 T s nn ca ng c 17,5

5 Khi lng ng c kg 545

6 Chiu rng ng c mm 585

7 Chiu cao ng c mm 8308 Chiu di ng c mm 1233

9 S xylanh ci 6

10 M men xon cc i ca ngc

Kg.m/vph 52,5/1400

11 Cng sut cc i ca ng c ml/vph 188/2900

12 Tc chy khng v/ph 550 600

13 Th t lm vic ca xylanh 1-5-3-6-2-4


26/100

- 24 -


1.2.1.2.3 H thng truyn ng

(1) (2) (3) (4)

1 Ly hp a n kh vi vng lxo(vn hnh bng thulc)

2 ng knh ngoi ca a mm 380

3 T s truyn- S 1- S 2- S 3

- S 4- S 5- S li

5 tin, 1 li, ng tc.4,6293,21642,582

1,4701,0407,216

4 S cu ch ng 1

5 H s gim sc 5,571:1

H. 1-5. Hp s

1.2.1.2.4 H thng treo

(1) (2) (3) (4)

1 H thng treo trc, sau Loi nhp l

2 Gim chn trc, sau Loi ng hai v, cchiu tc dng


27/100

- 25 -


1.2.1.2.5 H thng li

(1) (2) (3) (4)

1 Loi Lin hp (du v in)

2 Gc li trong v ngoi 47 1 v 33,9 1

3 Tay li Loi bi khng c tr lc

1.2.1.2.6 H thng nhin liu

(1) (2) (3) (4)

1 Dung tch thng nhin liu Lt 200

2 Dung tch thng nht Lt 13

3 Bm chuyn nhin liu Kiu piston

4 Bnh lc nhin liu Bnh lc giy

5 Bm cao p Kiu bm Bosh A

6 ng knh piston bm cao p mm 9,5

7 Vi phun-s vi phun cho 1 xylanh

-ng knh l phun

Vi

mm

1

0,31

1.2.1.2.7 H thng phn phi kh

(1) (2) (3) (4)

1 S lng van cho mi xylanh-Np-X

VanVan

11

2 Khe h xupap np mm 0,43 Khe h xupap x mm 0,4


28/100

- 26 -


1.2.1.2.8 H thng bi trn

(1) (2) (3) (4)

1 Bm du bi trn Bm bnh rng

2 Van an ton Kiu van bi

3 Lc du Kiu lc giy

4 Van iu khin Kiu van piston

1.2.1.2.9 H thng lm mt

(1) (2) (3) (4)

1 Phng php lm mt Bng nc ngt vi nhit nnh.

2 Bm lm mt Kiu ly tm

3 Nhit nc vo ngc

0C 50 60

4 Nhit nc ra ng c 0C 72

1.2.1.2.10 H thng khi ng(1) (2) (3) (4)

1 B khi ng in

H. 1-6. My khi ng


29/100

- 27 -


1.2.1.2.11 H thng phanh

(1) (2) (3) (4)

1 Loi h thng phanh Tr lc thu lc

2 ng knh trng phanh trc xrng

mm 370 x110

3 ng knh trng phanh sau x rng mm 370 x150

4 Phanh tay Kiu dy in

5 ng thng bnh xe trc mm 36,5

6 ng thng bnh xe sau mm 38,1


30/100

- 28 -


1.2.1.2.12 H thng x

S dng kh x cung cp cho tua bin tng p cung cp khng kh c p

sut cao vo bung t1.2.1.2.13 H thng in

(1) (2) (3) (4)

1 c quy (12V x 150Ah) x 2

2 Cng sut my pht in 24V 110A

3 Cng sut khi ng 24V 6kw

1.2.1.2.14 H thng ng m ca xe

Ca xe c ng m t ng bng kh nn

1.2.1.2.15 H thng lnh

-My lnh NANDO

+S qut thi:8 qut

+S qut nng:4 qut

-My nn mi cht lnh c dn ng t ng c

H. 1-7. V tr lp t my nn mi cht lnh


31/100

- 29 -


1.2.2 c im k thut v cu to ca ng c D6BR s dng trn xe but

Thnh Ph Nha Trang1.2.2.1 Gii thiu chung v v tr ng c trn xe but

ng c D6BR l ng c diesel do hng Huyndai ch to. Tt c xe but

Thnh Ph Nha Trang u dng loi ng c ny.

ng c D6BR l ng c 4 k, 6 xylanh b tr mt hng thng ng, tng

p, phun trc tip

ng c c bi trn bng mt h thng du p lc, nh mt bm bnh

rng cp du. piston c lm mt bng du nhn. Xylanh ng c l xylanh kh

thay th c mt cch r dng khi c h hng. ng c c lm mt bng h

thng lm mt tun hon kn, bm nc lm mt kiu ly tm.

ng c c b tr sau thng xe. S b tr ny khc phc c nhng

nhc im cc loi xe c kiu b tr ng c trc v ngoi bung li. b tr

nh vy m bo cch nhit, cch m tt cho ngi li v hnh khch ngi trn xe.

ng thi vic b tr nh vy gip cho vic bo qun v sa cha tt hn.

Bnh c quy v thng ngh c b tr pha di bn phi thng xe1.2.2.2 c im k thut ca ng c

- Kiu ng c :ng c diesel 4 k, 6 xylanh, 1 hng thng ng, tng p ,

lm mt bng h thng tun hon kn.

- Kiu bung t: bung t thng nht.

-ng knh xylanh: 118 mm.

- Hnh trnh piston: 115 mm.

-Dung tch xylanh: 7,545 cc

-Cng sut cc i: 188/2900 ml/vph

-Mmen xon cc i: 52,5/1400 kg.m/vph

-Tc chy khng nh nht: 500 600 rpm

- Tc chy khng ln nht: 3180 3220 rpm

-Kch thc ng c :

+Chiu di ng c: 1233 mm


32/100

- 30 -


+Chiu cao ng c: 830 mm

+Chiu rng ng c: 585 mm

+Trng lng ng c: 545 kg-T s nn: 17,5

-Phng php khi ng: khi ng in

-Cng sut khi ng: 24V/5kw

-Khe h xupap: 0,4 mm

-H thng nhin liu :

+Bm cao p: kiu Bosh A

+Vi phun: S l 5

ng knh l: 0,31 mm

Gc lch: 1600

+p sut phun: 220 kgf/cm2

+Loi nhin liu: diesel

+Lc nhin liu: li lc bng giy

+Th t n: 1-5-3-6-2-4-1-H thng bi trn:

+Bm du bi trn: bm bnh rng

+B lc du: li lc bng giy

+Nhit du bi trn: 70 900C.

-H thng lm mt

+Phng php lm mt: Lm mt nc ngt vi nhit n nh

+Bm nc lm mt: kiu ly tm

+Lm mt hng lot:22 lt

+B iu chnh nhit: Nhit m van: 80 900C

Nhit nng van: 950C

+B tn nhit: p sut m van 0,4 0,6 kgF/cm2 .


33/100

- 31 -


1.2.2.3 Nhm piston, xylanh, np xylanh

1.2.2.3.1 Nhm piston

Nhm piston gm nhng chi tit : piston, cc vng gng, cht piston v cihm cht. Piston nhn p lc kh t pha nh, truyn ti trc khuu, qua thanh

truyn v ngc li. N b nung nng bi kh chy trong bung t. Nh vy piston

va b ti c va chu ti nhit. p sut cao nht trn nh piston khong (60-120)

KG/cm2 .Nhit trung bnh u piston khong (400-500)0C. Ngoi ra, khi

chuyn ng, cc vng gng v phn dn hng ca piston cn chu mi mn mnh

do ma st vi xylanh nhit cao v bi trn km gy ra.

Cng vi xylanh v np xylanh to thnh bung lm vic kn ca ng c ,

nhng piston li chuyn ng. Nhim v lm kn ca n cn m li kh. Phi tht

kn nhng li cho php chuyn ng d dng ma st t.

Cc vng gng hi v vng gng du l tit my ph trong khp trt piston-

xylanh m bo c nhim v ny.

Vt liu v cu to nhm piston phi lm sao cho n chu c ti c, ti

nhit; t b mi mn v m bo kh lt xung hp cacte t nht, du lt ln bungt t nht.

Piston ng c D6BR c c bng hp kim nhm c s gin n nhit nh

v to nhit tt. nh piston lm, bung t nm trong nh piston. c bit l p

chuyn ng khng kh theo vng xoy trong xylanh.

Piston c 3 vng gng: 2 vng gng kh v 1 vng gng du lp trn u

piston. Vng gng th nht chu la c m crom tng bn.

ng c D6BR c bung t thng nht loi phun trc tip.

u im: kt cu n gin, din tch bung t b nn t tn tht nhit, t hao

nhin liu, khi ng r dng m khng cn bugi xng my.

Nhc im: t s nn cao, p sut du ln

Piston c lm mt bng du bi trn t di ln nn piston t b qu nhit,

gin n nh, t gy ng sut v b kt piston.


34/100

- 32 -


Piston:-Khe h cht piston

+Kch thc tiu chun:0,01 0,02 mm

+Kch thc gii hn:0,05 mm

-Khe h gia cht piston v thanh truyn


Cht piston-ng knh ngoi cht piston:


+Kch thc gii hn: 38,05 mm

Vng gng pistonVng gng Kch thc tiu

chun (mm)Kch thc gii

hn (mm)

Khe h gia vng gng v rnh vng gng-Vng gng la-Vng gng th 2

-Vng gng du

0,09 0,130,05 0,08

0,03 0,06

0,20,15

0,15Khe h u vng gng 0,35 0,55 1,5


35/100

- 33 -


H. 1-8. Piston

H. 1-9. Hnh dng nh piston


36/100

- 34 -


1.2.2.3.2 Xylanh

ng xylanh cng piston to ra khp trt trong c cu piston-thanh truyn

trc khuu. ng thi n cng np xylanh v nh piston to ra bung lm vic cang c. lm tt 2 nhim v trn ng xylanh phi kn v cho piston trt d

dng

ng c D6BR s dng lt xylanh kh, xylanh c lm mt nhit

khng i bng nc. Xylanh c c bng thp c bit, c kh nng chng mn

v h hng cao. N l chi tit c dy tiu chun, chng gin n cc b v c

tng bn.

Tn thng s Kch thc tiu chun(mm)

Kch thc gii hn (mm)

ng knh trong cxylanh

118,000 118,030 118,25

Phn nh ra ca xylanh 0,03 0,10

H. 1-10. Hnh dng lt xylanh

1.2.2.3.3 Np xylanh

Np xylanh cng xylanh v nh piston to ra bung lm vic ca ng c,

nht l hnh dng v th tch ca bung t. Np xylanh chu p lc kh ln v nhit

cao.

Np xylanh ng c D6BR c c bng loi thp c bit, trn np xylanh

b tr xupap ht, x,vi phun, ca x, ca np, ng nc lm mt


37/100

- 35 -


C th ni: np xylanh l tit my rt phc tp v mt cu to. ng thi ng

sut c, ng sut nhit va cao, va rt chnh lch gia cc vng. Chnh v vy,

thnh vch ca np xylanh phi lm sao c b dy tng i u trnh nt khi tinng, nhit cao.

ng c D6BR mi xylanh c 1 xupap ht, 1x.

ng knh x bcren (mm)

M14x2,0Gi tr lc sitbulng np xylanh

Lc sit (kgf/m) 20 22

H.1-11. Mt di np xylanh ( mt tip xc vi bung t)

H. 1-12. Mt trn np xylanh

H. 1-13. n gnh, trc n gnh, np y


38/100

- 36 -


H. 1-14.iu chnh khe h nhit

1.2.2.4. H thng nhin liu

1.2.2.4.1.Nhim v, yu cu,cu to:

H thng nhin liu c nhim v lc sch ri phun nhin liu vo bung t

theo cc yu cu sau:

Cung cp vo bung t nhng khi lng du xc nh, ph hp vi ch lmvic nh ca my v c th iu chnh c

Thi im v thi gian cung cp phi chnh xc ( nht l thi im bt u ) v cth iu chnh c

Du a vo phi dng cc ht nh, ng u (kch thc ht c 3 5 ) vphn b u trong khng gian bung t. To iu kin cho du bay hi d dng,

nhanh chng v ho trn u vi khng kh nn, thnh hn hp d t bc chy nht.

S lng du cung cp theo thi gian cung cp - lut cung cp - phi to ra s cpnhit tt nht cho chu ch nh lm vic ca my. Ngha l: khng qu nhiu giai

on trc im cht trn mc tng p trong giai on chy ng tch khng

qu cao, my lm vic khng b cng. cng khng qu nhiu giai on sau,

my khng b gim hiu sut nhiu v khng b qu nng.


39/100

- 37 -


H. 1-15. H thng nhin liu

1- Bnh lc kh ; 2- Hi du vi phun; 3- Vi phun; 4- ng cao p; 5- Bnh

lc th; 6- Bnh lc tinh; 7- Kt nhin liu; 8- Van kho; 9- Nt x du; 10- Bm

thp p; 11- ng hi du; 12- Bm cao p


40/100

- 38 -


1.2.2.4.2.Vi phun:

Chc nng phun nhin liu cao p vo bung t vi cu trc tia nhin liu

ph hp vi phng php t chc qu trnh chy.c im vi phun ng c D6BR:

-Kiu 5 l.

-p sut phun 220-230kg/cm2 .

-ng knh X s l X gc lch: 0.31 X 5 X 160 (mm X l X )

Nguyn l hot ng: Bm cao p cung cp du c p sut cao vo vi phun.

Khi p lc du n mt gi tr nh mc ln thng c p lc l xo iu

chnh, kim phun s c nng nn tch khi b ca n trn u phun, du s

c phun vo bung t. Nhin liu phun ra di dng sng m, khi p sut du

t 220 kg/cm2 th du nng kim phun khi b v phun vo bung t qua l vi

phun

u im ca vi phun nhiu l:

-p sut phun cao hn vi phun 1 l

-Bn hn, t b chy, b kt kim phun-Khi phun mi l cho ra mt tia vi gc nn nh, cc tia hp vi nhau to

gc nn ln ph hp vi loi bung t thng nht

Nhc im: Vi phun nhiu l d gy tc nghn cc l phun.

H. 1-16. Vi phun


41/100

- 39 -


H. 1-17. Cc chi tit tho ri ca vi phun nhin liu

R- ng rc co du vo; F- Khu sit u phun vo thn vi phun; B- u

phun; A- Kim phun; I- Thn vi phun; P- Trc y; r- l xo; a- a ta l xo; E-


42/100

- 40 -


ai c vt iu chnh p sut phun du; C- c kho; T- Vt iu chnh p sut phun

du.

H. 1-18. Cu to ca vi phun

1- u phun; 2- Kim phun; 3- c chp u phun; 4- Cht; 5- Trc y; 6-

c nh v vi phun vo np xylanh; 7- Thn vi phun; 8- L xo; 9- ai c chp l

xo; 10- ai c vt iu chnh p xut phun du; 11- Np y; 12- Bc; 13- Ci lc

khe; 14- u ni ng; 15- Rnh du; 16- m; 17, 19- Mt cn kn st; 18- Khoang

du cao p; 20- L phun

1.2.2.4.3.Bm cao p:

Chc nng:

- Nn nhin liu ti p xut rt cao ( khong 100 1500 bar ) ri y n vi

phun (chc nng nn).


43/100

- 41 -


- iu chnh lng nhin liu cung cp vo bung t ph hp vi ch

lm vic ca ng c ( chc nng nh lng ).

- nh thi im bt u v kt thc qu tr nh phun nhin liu (chc nngnh thi).

c im k thut bm cao p ng c D6BR:

-Kiu Bosch A

-Th t phun: 1-5-3-6-2-4

-ng knh piston bm: 9.5 (mm)

-Khe h y trc cam iu khin: 0.02-0.06 (mm)

-Khe h gia thanh rng iu khin v bnh rng chuyn:

+Kch thc tiu chun: 0.15 (mm)

+Kch thc gii hn: 0.3 (mm)

-Bm cao p ng c D6BR c 6 piston bm c dn ng bng trc cam.

mi piston bm phc v cho 1 vi phun. V vy s xylanh bm bng s xylanh

ng c.

u im: Gc phun sm c iu chnh ph hp vi mi ch lm vicca ng c. kt cu thn bm gn nh, dng bm piston ngn ko d iu chnh

tu lng nhin liu.

Nhc im:Cu to phc tp, iu chnh v sa cha kh khn.

-Bm cao p ng c D6BR c thn bm, cc cp piston-xylanh, van trit

hi, trc cam, con i v c cu xoay piston.

Piston v xylanh l 2 b phn lm vic c bn ca bm, cp piston-xylanh

c ch to chnh xc bng thp hp kim, nhit luyn n cng cao. vic lp

ghp cp piston-xylanh i hi chnh xc m bo nhin liu khng b r r. Van

trit hi v van cng l mt cp lp ghp i hi chnh xc.


44/100

- 42 -


Nguyn l hot ng

H. 1-19. Cu to chi tit ca bm cao p1- Bi kim; 2- Trc con ln; 3- Con ln; 4- Con i; 5- Bulon; 6- ta di;

7- Piston; 8- c gi np thm; 9- L xo bm; 10- c xoay piston; 11- Np thm;

12- Vt nh v xylanh; 13- Xilanh; 14, 15- v thn van cao p; 16- L xo valve

cao p; 17- L ht v x du; 18- Khoang cha du p sut thp; 19- Thanh rng-

thc nhin liu; 20- Vnh rng; 21- c hm vnh rng; 22- Thn bm; 23- bi;

24- Trc cam bm cao p; 25- rnh nh hng; 26- Vt x kh.


45/100

- 43 -


H. 1-20. Cc chi tit tho ri ca bm cao p

1- L xo van nn; 2- Van nn; 3- V bm; 4- Np; 5- V bi; 6- Gi ; 7-Thanh rng iu khin; 8- Trc cam; 9- V iu khin.

H. 1-21. Nguyn l lm vic ca bm cao p


46/100

- 44 -


H. 1-22. Hnh nh bm cao p thc t

Khi piston ngn ko 7 v tr thp nht, du qua l 0 v 01 np y khoang

nh piston. Lc con i 4 c cam du i, n s y piston i ln, cho n khi

nh piston va y kn cc ca 0 v 01th du c tng p, thng lc l xo 16,

nng valve cao p ln, bt u cung cp du ln ng cao p, a ti vi phun. S

cung cp tip tc cho n khi mp vt iu chnh ca piston h m ca 01, th du

t trn nh piston theo rnh dc, qua ngn ko u piston thot ra ca 0 v 01,

kt thc qu trnh cung cp.

1.2.2.4.4 ng dn nhin liu.

Gm c ng cao p v ng thp p. ng cao p dn nhin liu c p sut cao

t bm cao p n vi phun, vt liu ch to i hi phi chu c p lc cao. ng

thp p dn nhin liu t thng cha n bm cao p v dn nhin liu hi v thng

cha.1.2.2.4.5 Lc nhin liu.

Trong h thng nhin liu ca ng c diesel c cc b phn c ch to v

lp rp vi chnh xc rt cao, nh : u phun, cp piston xylanh ca bm cao p,

van trit hi. Cc b phn ny rt d bi h hi nu trong nhin liu c tp cht c

hc. Trong du c ln c nc, nc ln trong nhin liu s lm cho nhin liu

khng chy c lc phun vo bung t, ng thi lm cho ti bm kt cng trong


47/100

- 45 -


xylanh bm gy nn gy hng. Bi vy nhin liu phi c lc sch trc khi n

bm cao p.

H. 1-23. V tr cc b lc trong h thng nhin liu

a) Lc s cp.

Bu lc s cp t gia thng nhin liu v bm tip vn. Li ca lc ny

lm bng li ng c l tha khong 0,1 mm, bn ngoi li lc c ci co. Khi taxoay nm, pha di bu lc, co s lm ri cn bn quanh li lc xung y bu

lc. Nt x nc v cn bn b tr di y bu lc.

H. 1-24. Kt cu bu lc s cp


48/100

- 46 -


b) Lc th cp.Li lc th cp l nhng khoanh n dy chng bn ngoi mt ng nhiu l.

Nhin liu t bu lc s cp vo l D, chui qua lp n vo ng trung tm thotxung l E n bm cao p. Bn trong rc co du d tr v c b tr van du trn.

Cng dng ca van ny l bo m mt p sut tip vn ti thiu buc nhin liu

phi chui qua lp b lc cung cp cho bm cao p. Van c cu to gm mt vin

bi trn v l xo. Nu khi sc ra bu lc ta nh ri hay lm hng van ny, nhin

liu s khng cung cp cho bm cao p, ng c gim cng sut thy r. Khi p

sut tng qu khong 0,5 kG/cm2, van m cho nhin liu trn tr li thng cha.

H. 1-25. Kt cu bu lc th cp

1.2.2.4.6 Bm thp p.Bm thp p c nhim v a du t qua bnh lc tinh ti bm cao p.

Nng sut ca bm chuyn phi bng (1,5 2 ) ln lng cung cp nh mc

ca ng c. Ct p c xc nh theo v tr tng i ca bm thp p, bnh lc

v bm cao p v phi ln thng tr lc ng ng v ch yu to ra p

sut thm thu qua lc.

ng c D6BR c trang b bm thp p kiu piston.


49/100

- 47 -


u im: c th iu chnh c p lc du theo yu cu.

Nhc im: Cu to phc tp.

C cu iu chnh: nu dch chuyn thanh rng v pha trc ca b iu tclng cung cp nhin liu tng nn v tin hnh ngc li th lng nhin liu

gim.

1.2.2.4.7 B iu tc.

B iu tc dng trn ng c D6BR l b iu tc mi ch . nhim v b

iu tc l gi cho tc quay ca ng c mt gi tr khng i cho d ti ca

ng c c thay i bt k tc l thay i lng cung cp nhin liu cho ph hp

vi mi ch hot ng ca ng c.

H. 1-26. B iu tc1- Bn p; 2- Thanh rng nhin liu; 3- Tay n;

4- Qu vng; 5- Khp trt; 6- l xo

Nguyn l hot ng: y bn p 1 s thay i bin dng ban u ca l xo

6. Mi v tr bn p 1 s tng ng vi mt tc iu khin lc ly tm ca qu

vng 4 thng lc l xo lm qu vng 4 chuyn dch xa tm quay v y khp trt 5

sang tri ng thi ko thanh rng 2 v pha gim gct, thc hin nhim v iu chnh

tc ng c .


50/100

- 48 -


1.2.2.5 H thng np - x

H thng np- x (cn gi l h thng thay i kh hoc h thng trao i kh) cchc nng lc sch khng kh ri np vo khng gian cng tc ca xylanh v x kh

thi ra khi ng c, cc b phn c bn ca h thng np-x bao gm: lc khng

kh, ng np, ng x, bnh gim thanh v c cu phn phi kh

Gi tr lc sitTn thng s ng knh x bc ren(mm) Lc sit(kgf/m)

Bulng ng gp np

ai c ng gp xM8x1,25M10x1,25

1,9 2,84,2 4,6

1.2.2.5.1 Cu to ng gp np

H. 1-27. Cu to ng gp np

1- Np, 2-m lt


51/100

- 49 -


1.2.5.1.2 Cu to ng gp x

H. 1-28. Cu to ng gp x

1- ng gp x; 2- m; 3- Np

1.2.5.1.3Lc khng kh:

chc nng lc sch khng kh trc khi vo bung t. lc khng kh ca

ng c D6BR c cu to nh hnhv

H. 1-29. Lc khng kh

1- Thn; 2- Phn t lc; 3- Np


52/100

- 50 -


1.2.2.5.4 C cu phn phi kh

C cu phn phi kh c chc nng iu khin qu tr nh np kh mi vo

khng gian cng tc ca xylanh v x kh thi ra khi ng c.Yu cu vic np phi y. Ngha l h s np phi cao. Vic x phi sch.

Ngha l h s kh st phi thp.

H. 1-30. C cu phn phi kh

1- Trc cam; 2- Con i; 3- m; 4- ng dn hng; 5- ng chn trn; 6-

a y; 7- Vt iu chnh; 8- n gnh; 9- Trc n gnh;10- trc n gnh;

11- Mng hm; 12- Cone hm; 13- Vnh khuyn hm; 14- L xo xupap; 15-

Xupap; 16- Bc n gnh; 17- a ta l xo xupap; 18- Bc dn hng;

a)Xupap

Xupap l mt loi van c trng ng c t trong, c chc nng ng, m

ng ng np v x. Mi xylanh ca ng c D6BR c 1xupap np chc nng


53/100

- 51 -


ng m ng ng np, 1xupap x chc nng ng m ng ng x. xupap b tr

theo kiu treo trong np xylanh. Trong qu trnh ng c hot ng, xupap x chu

tc dng thng xuyn ca kh thi c nhit cao, nhit ca nm xupap x cth ti 600-7000C, cho nn n c ch to t thp hp kim cht lng cao. Xupap

np thng xuyn c lm mt bng dng kh mi nn nhit ca n khong

400-5000C . tng cng lu lng kh np vo bung t, nm supap np ln

hn nm xupap x.

b) n gnh

n gnh di chuyn ln v xung bng lc nng ca cam qua con i v a

y lm m hoc ng xupap np, x. u n gnh pha a y c b tr 1vt

iu chnh khe h nhit.

c) a y

a y c ch to bng thp ng, thnh mng. hai u c dng chm

cu. a y chuyn ng qua li dc trong ng dn hng n n gnh.

d) Con i

Con i truyn chuyn ng tnh tin cho a y. Con i chuyn ngquay quanh ng tm ca n s lm cho mt tip xc ca con i vi cam mn

u.


54/100

- 52 -


Tn thng s Kch thc tiu

chun(mm)

Kch thc gii

hn(mm) cong ca a y 0,4

ng knh ngoi con i 31,06 31,10

ng knh trc n gnh 24,01 24,08

ng knh ngoi thn van 8,96 8,97 8,85

ng knh trong ng dn hng van-Np

-X

9,04 9,06

9,07 9,10Ti trng ca l xo(N)-L xo trong-L xo ngoi

93240

20579

di t do ca l xo-L xo trong-L xo ngoi

55,158,1

52,155,1

Gi tr lc sit bulng n gnh ng knh x bc

ren(mm)M8x1,25M10x1,5

Lc sit(kgf/m)

1,03,5

e) Trc cam

Trc cam lm bng thp thng, c trc v mt cam c ti b mt v mi

bng. Bin dng cam l mt ng cong lin tc c c tnh gim chn, s lm

gim va p theo chu k trn xupap v lm tng bn cho trc cam.

Tn thng sKch thc tiu chun

(mm)Kch thc gii hn

(mm)

Chiu cao vu cam- Cam van np- Cam van x

49,54749,307

49,04748,807


55/100

- 53 -


CHNG 2. KH NNG S DNG NHIN LIU THAY

TH CHO I XE BUT THNH PH NHA TRANG

2.1. Phng n lp t h thng s dng nhin liu thay th cho ng cdiesel

D6BR trn xe but thnh ph Nha Trang.

2.1.1. H thng s dng nhin liu thay th n

H thng s dng nhin liu thay th n l h thng ch s dng duy nht

mt loi nhin liu thay th.

u nhc im ca h thng s dng nhin liu thay th n

* u im:- Do ch s dng mt loi nhin liu thay th ( Biodiesel, LPG ) nn vic ci

hon h thng nhin liu diesel ban u ca xe s dng nhin liu thay th khng

qu phc tp.

- Vic vn hnh, bo dng sa cha n gin hn khi s dng lng nhin

liu.

- Gi thnh ci hon cng thp hn do t phi thay th kt cu ban u

Nhc im

Kh khn khu tip nhin liu thay th, hin nay trn cc tuyn ng

cha c hoc c nhng rt t trm nhin liu thay th (biodiesel, LPG ), v vy lm

gim tnh c ng ca xe

2.1.2 H thng s dng nhin liu thay th v diesel song song.

H thng s dng nhin liu thay th v diesel song song l h thng c th

chuyn i mt cch d dng t dng nhin liu thay th sang nhin liu diesel vngc li trn cng mt ng c trong qu trnh hot ng

u, nhc im

u im:

- Xe c th chy nhin liu thay th hoc chy nhin liu diesel, v vy gii

quyt tt tnh trng tip nhin liu.


56/100

- 54 -


- C th la chn loi nhin liu s dng ph hp vi thc t s dng v vy

va m bo tit kim ti a chi ph cho nhin liu ng thi vn m bo tnh nng

tt nht cho xe. Xe c th chy mi ni m ngi li khng s thiu nhin liu

hoc gi nhin liu cao. Nu xe chy trong thnh ph ta s dng nhin liu thay th

( Biodiesel, LPG ) m bo vn nhim, cn nu xe chy ngoi thnh ph c

th chuyn sang s dng nhin liu diesel m bo cc tnh nng tt nht ca xe.

* Nhc im

- Cu to xe ch nn phc tp, gi thnh chuyn i cao

- S dng 2 loi nhin liu nn ta phi tnh ton, iu chnh sao cho ng clm vic tng i n nh c hai loi nhin liu, khng khc bit ln

- Nu van ng ngt khng tt gy hin tng c hai loi nhin liu cng vo

ng c.

2.1.3 La chn gii php.

Hin ti Thnh Ph Nha Trang khng c trm tip nhin liu thay th

(Biodisel, LPG) no. vic chuyn i ng c xe but ca Thnh Ph sang s

dng nhin liu thay th c th tr thnh hin thc vi chi ph nh nht ( xy dng

s trm tip nhin liu thay th t nht ) m khng nh hng n nhim v vn

chuyn hnh khch trong Thnh Ph v vng ven, Ti chn phng n ci to ng

c xe c th s dng nhin liu thay th v diesel song song.

2.2 Gii php k thut ng c c th s dng nhin liu Biodiesel.

So vi du diesel nht ca biodiesel cao hn , tng hiu qu kinh t v

hiu sut ng cta nn sy nng nhin liu. Vn sy nng nhin liu nhm mc

ch c bn l lm gim nht ca Biodiesel v gn vi nht ca diesel nht,

v vy mt s hn hp ca Biodiesel vi diesel c nht gn bng nht ca

diesel nguyn cht nh B5, B10, B20,ta khng nht thit phi sy nng m c th

dng trc tip nh nhin liu diesel thng thng.

Di y tr nh by s nguyn l h thng nhin liu s dng nhin liu

biodiesel cho ng c D6BR


57/100

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H. 2-1. S h thng nhin liu dng nhin liu Biodiesel

1 Vi phun 5 Bnh sy

2 Bm cao p 6 Kt nhin liu Biodiesel

3 Bnh lc 7 Van chn

4 Van ba ng 8 Kt nhin liu Diesel

Nhin liu biodiesel t kt 6 qua van chn ti b nh sy 5, ti y nhin liu

biodiesel c sy nng n nhit quy nh, lm nht ca nhin liu gim

sung theo yu cu s dng. Van ba ng 4 c nhim v ch cho mt loi nhin liuduy nht qua n (diesel hoc biodiesel) theo yu cu s dng. Nhin liu t van 4

qua bnh lc 3 lm sch, sau c bm cao p 2 chuyn n vi phun 1

vo bung t.

C nhiu cch sy nng nhin liu trc khi n vi phun. Di y trnh

by ba phng php thng dng sy nng nhin liu trc khi n vi phun

trn t.


58/100

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2.2.1 Bnh sy s dng nc lm mt lm nng nhin liu

Nc lm mt sau khi i lm mt ng c c nhit cao c a ti bnh chanc nng 2, ti y n cp nhit v lm nng nhin liu biodiesel trong ng xon

rut g 1. Nhin liu biodiesel sau khi c nc lm mt sy nng c a ti

bm cao p.

H. 2-2. S nguyn l bnh sy s dng nc lm mt sy nng nhin liu

1 - ng xon rut g; 2 Bnh cha nc lm mt; 3 - Nhit k

S h thng nhin liu dng du biodiesel, c s dng b nh sy nng

nhin liu bng nc lm mt.


59/100

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H. 2-3. S h thng nhin liu dng du Biodiesel, c s dng bnh sy nng

nhin liu bng nc lm mt

1 Kt nhin liu Diesel 7 Van x nc sau khi sy nhin liu2 - ng cp nc b sung 8 Bnh sy nhin liu

3 Kt nc lm mt 9 Bnh lc th

4 - Nhit k 10 Van ba ng

5 Kt nhin liu Biodiesel 11 Bnh lc tinh

6 Van chn 12 Nhin liu ti bm cao p


60/100

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2.2.2 Bnh sy s dng ngun in mt chiu

Tn dng ngun in mt chiu ca ng c trong h thng khi ng to

ra ngun nhit cung cp cho b sy.u im: sy c lng nhin liu ln, iu chnh nhit nhin liu cn

sy mt cch d dng, c th sy nng nhin liu trong khong gii hn nhit

rng.

Nhc im: tiu hao in s dng cho vic sy nhin liu

S nguyn l s dng ngun in mt chiu cho bnh sy

H. 2-4. S nguyn l s dng ngun in mt chiu cho bnh sy

1 Nhin liu cn sy i vo 6 c qui2 Van chn 7 - Cm bin nhit 3 Van phao 8 Bnh cha nhin liu sy4 Que sy 9 Van chn5 - Thit b iu khin 10 Nhin liu ti bm cao pNguyn l hot ng: Nhin liu cn sy nng c a vo bnh cha nhin

liu 8, ti y nhin liu c sy nng nh que sy 4, que sy 4 c cp in t

c qui 6 bin in nng thnh nhit nng. Vic cp in nh vo thit b iu khin

5, cm bin nhit 7 c nhim v cung cp thng tin v nhit cho thit b iu

khin 5 lm vic, nhin liu sau khi c sy nng uc a ra ngoi qua van chn

9 theo ng 10 ti bm cao p


61/100

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2.2.3 Bnh sy tn dng ngun nhit kh x

u im: Tn dng c ngun nhit kh x c sn ca ng c, thit b ch

to n gin, thi gian sy nng nhin liu ngn.Nhc im: tin cy khng cao, kh iu chnh, nhit kh x ph thuc

vo ti ca ng c nn khng n nh.

S nguyn l bnh sy dng ngun nhit kh x.

H. 2-5.

H. 2-5. S nguyn l bnh sy dng ngun nhit kh x

1 Kh x t ng c 7 - Nhit k

2 Kh x ra 8 Khoang kh x

3 Van iu chnh lu lng kh x 9 Bnh sy

4 - Ca gi 10 Kh x ra

5 - ng ni mm 11 Nhin liu vo

6 - Qut gi 12 Nhin liu ra


62/100

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Nguyn l hot ng: Kh x t ng c 1 c trch mt phn qua van 3 i

lm nhim v sy nng nhin liu, nh ca gi 4 dng kh x i hng ti ng 5

v i vo khoang kh x vo 8 di sc ht ca qut gi 6, ti bnh sy 9 xy ra qutrnh trao i nhit ca dng kh x nng chy ngoi ng v du biodiesel chy

trong ng, kh nng sau khi cp nhit cho nhin liu c a ra ngoi theo ng

10 ti bm cao p.

2.2.4 La chn

Qua trnh by trn ta thy rt r u nhc im ca tng phng php sy

nng nhin liu. cho kt cu ca xe khng qu cng knh, thao tc n gin,

tin cy cao, mang tnh thm m, hin i, ph hp vi chc nng vn chuyn hnh

khch trong ni v vng ven thnh ph. Ta nn chn phng php sy nng

nhin liu bng bnh sy s dng ngun in 1 chiu.

2.2.5 S tng th h thng nhin liu s dng Biodiesel v Diesel song song

(H. 2-6 )

Trong tt c cc b phn chuyn i lp ln xe, Kt nhin liu l b phn chim

nhiu khng gian nht. to m quan v khng lm thay i nhiu kt cu ca xe,ti chn gii php tho kt nhin liu diesel ban u v thay vo v tr hai kt

nhin liu diesel v Biodiesel mi vi t l th tch thch hp.


63/100

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2.3 Gii php k thut ng c c th s dng nhin liu LPG.

2.3.1 Gii php k thut ng c c th s dng LPG v diesel song song.

ng c c th s dng LPG v diesel song song ta phi ci tin sao choch vi thao tc chuyn i n gin, ng c c th chuyn t chy nhin liu

diesel sang chy LPG vi diesel lm chc nng phun mi v ngc li. Ni mt

cch c th ta phi a ra gii php k thut h thng nhin liu diesel c th

chuyn t chc nng phun diesel thng thng sang chc nng phun mi v ngc

li ch bng thao tc nhn nt hay gt cn chuyn i. ng thi a ra gii php k

thut lp t h thng cung cp LPG trn ng c. Di y trnh by c th nhng

ni dung nu trn.

2.3.1.1 Gii php k thut h thng nhin liu diesel c kh nng phun mi

2.3.1.1.1 C s l thuyt.

tn dng ti a cc b phn ca h thng nhin liu diesel ang s dng

trn xe but, ng thi hn ch ti thiu vic phi lp t thm nhiu c cu, b

phn khc lm thay i qu ln kt cu v tng chi ph cho vic ci to. Ta s dng

nh la bng cch phun nhin liu minh la bng cch phun nhin liu mi l nh la c thc hin bng s

t chy ca mt lng nh nhin liu diesel phun trc khi piston n im cht

trn.

Nguyn tc ny ging nh ng c diesel, ch c khc l vic iu chnh

cng sut c thc hin bng cch iu chnh th tch kh ga np vo xylanh cn

lng nhin liu diesel phun mi vn gi c nh. Ngi ta gi loi ng c ny l

diesel-gas hay lng nhin liu.

Cc ht nhin liu diesel phun vo bung chy s t bc chy v to ra

chng y im nh la trong hn hp nhin liu-khng kh.

So vi h thng nh la c in dng tia la in, ngi ta thy h thng

nh la kiu ny hiu qu hn nhiu v nng lng do n to ra cao gp nghn ln

so vi h thng nh la tia la in truyn thng v n hu nh khng ph thuc


64/100

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vo s phn b hn hp trong bung chy. Trong trng hp , s ra tng p sut

din ra nhanh chng hn v hiu sut ng c c ci thin ng k.

ch lm vic n nh, s gia tng p sut ca loi ng c ny tng tng c Diesel.

Lng nhin liu phun mi rt nh, nh hn c lng nhin liu cn thit

duy tr ch khng ti ca ng c Diesel.

u im ca nh la bng cch phun nhin liu mi

- tin cy khi nh la cao, hiu qu nh la ko di v c th nh la

vi bt k m c no ca hn hp vi iu kin l mc ri ca hn hp ga-

khng kh ln.

- D dng chuyn i sang li ng c Diesel khi c s c h thng gas.

- Hiu sut nhit ng hc cao.

Nhc im ca nh la bng cch phun nhin liu mi.

T s nn cao lm hn ch cng sut cc i theo tnh cht nhin liu kh.

Mc d kh nng chng kch n ca LPG cao nhng nu t s nn cao hn mc cho

php s gy hin tng kch n lm cng sut ng c gim, sut tiu hao nhin

liu tng v gy h hng ng c . Trong khi , vic nh la bng tia la in

cho php la chn t s nn ti u cho tng loi ga s dng. Tuy nhin vic gim t

s nn s dn n vic gim hiu sut nhit ca ng c.


65/100

- 63 -


2.3.1.1.2 Gii php lp t thit b iu khin lu lng du diesel trn ng

cao p.

Cu to v nguyn l hot ng ca thit b iu khin lu lng du diesel.

H. 2-7. Cu to thit b iu khin lu lng du diesel

1 - Cun dy 5 - Du n vi phun2 Li thp 6 - Du hi3 Ty van 7 Van mt chiu4 - Du t bm cao p nThit b iu khin lu lng du gm ba b phn chnh:

-ng hnh tr, hai u c ren ni vi ng cao p t bm cao p ti v ngcao p dn ti vi phun.

-Van in t c nhim v ng m van lm thay i lu lng qua ng.

-ng hi du c nhim v hi du d v bm vn chuyn.

Nguyn l hot ng: khi khng cp in, van in t ng, ty van 3 lm chotit din ng ti v tr nh li, lu lng du diesel theo ng 5 ti vi phun ti, thc hin chc nng phun nhin liu mi, do cht lng khng chu nn nn psut du pha 4 tng nn, khi p sut vt qu gii hn cho php, van mt chiu 7 sm ra, hi du theo ng 6 v bm vn chuyn. Khi cp in, cun dy 1 to ra ttrng ht li thp 2 i ln ng thi ko ty van 3 nn, lu lng du qua ng nvi phun tr li b nh thng thc hin chc nng ca h thng cung cp nhinliu diesel thng thng.


66/100

- 64 -


Cu to v nguyn l hot ng ca h thng nhin liu c lp t thit b iu

khin lu lng du trn ng cao p.

H. 2-8. Cu to ca h thng nhin liu c lp t thit b iu khin lu

lng du trn ng cao p.

1- Bnh lc kh ; 2- Hi du vi phun; 3- Vi phun; 4- ng cao p; 5- Bnhlc th; 6- Bnh lc tinh; 7- kt nhin liu; 8- Van kho; 9- nt x du; 10- bm thpp; 11- ng hi du; 12- Bm cao p; 13- Thit b thay i lu lng du; 14- ngdn ga.


67/100

- 65 -


Nguyn l hot ng: Bm 10 ht nhin liu diesel t b nh cha 7 qua lc

th 5 vo bm ri c bm qua bnh lc tinh 6, ti bm cao p 12. Cc bnh lc 5

v 6, lc sch cn bn ln trong nhin liu. Bm cao p y nhin liu i tip nthit b iu khin lu lng 13. Ti y nu van in t ng th ch mt phn nh

nhin liu i tip vo ng cao p 4, ti vi phun phun vo bung chy ng

c, nhin liu d tha thit b iu khin lu lng qua ng hi du 11 tr v

ca ht ca bm chuyn nhin liu 10. Nu van in t m th ton b du t bm

cao p vo ng cao p 4 ti vi phun phun vo bung t, ng hi du 11

ch nhn c du d tha t bm cao p. Mt phn nhin liu r r trong vi phun

i theo ng 2 tr v thng cha.

Khng kh t ngoi tri qua bnh lc kh 1 vo ng np. Ti y nu ng c

ang chy ch ch dng diesel th khng kh s qua xupap np vo bung t,

nu ng c chy bng LPG th khng kh s c ho trn cng vi LPG t ng

14, sau hn hp kh-gas mi qua xupap np vo bung t.

Nhc im c bn ca gii php ny l vic lp t thit b iu khin

lu lng trn ng cao p i hi phi kn st, cc b phn ca thit b phi chuc p sut cao. Mi ng cao p dn n vi phun i hi phi lp t mt thit

b iu khin lu lng v vy dn n chi ph tn km, iu khin v sa cha thit

b kh khn, phc tp.

2.3.1.1.3 Gii php lp t thit b iu khin lu lng du diesel trn ng

thp p.

Cu to v nguyn l hot ng ca thit b iu khin lu lng du

diesel trn ng thp p.

Cu to v nguyn l hot ng ca thit b iu khin lu lng du diesel

trn ng thp p cng ging nh thit b iu khin lu lng du diesel trn

ng cao p. Chng ch khc nhau v vt liu ch to v kn st ca cc chi tit

cu thnh.

Cu to v nguyn l hot ng ca h thng nhin liu c lp t thit b

iu khin lu lng du trn ng thp p.


68/100

- 66 -


H. 2-9. Cu to ca h thng nhin liu c lp t thit b iu khin lu

lng du trn ng thp p.

1- Bnh lc kh ; 2- Hi du vi phun; 3- Vi phun; 4- ng cao p; 5- Bnhlc th; 6- Bnh lc tinh; 7- Kt nhin liu; 8- Van kho; 9- Nt x du; 10- Bmthp p; 11- ng hi du; 12- Bm cao p; 13- Thit b thay i lu lng du; 14-ng dn ga.


69/100

- 67 -


Nguyn l hot ng: Bm 10 ht nhin liu diesel t b nh cha 7 qua lc

th 5 vo bm ri c bm qua bnh lc tinh 6, cc bnh lc 5 v 6, lc sch cn

bn ln trong nhin liu. Nhin liu t b nh lc tinh i tip n thit b iu khinlu lng 13. Ti y nu van in t ng th ch mt phn nh nhin liu i tip

n bm cao p 12, lng nhin liu ny c bm cao p y qua ng cao p 4

ti vi phun vo bung chy ng c, nhin liu d tha thit b iu khin lu

lng qua ng hi du 11 tr v ca ht ca bm chuyn nhin liu 10. Nu van

in t m th bm cao p s y lng du nh mong mun t bnh lc tinh 6 vo

ng cao p 4 ti vi phun phun vo bung t, ng hi du 11 ch nhn

c du d tha t bm cao p. Mt phn nhin liu r r trong vi phun i theo

ng 2 tr v thng cha.

u im ca gii php ny l ta ch cn lp t duy nht mt thit b iu

khin lu lng du trn ng thp p c th lm thay i lng du phun vo

bung t ca tt c 6 vi phun trn ng c .


70/100

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2.3.1.1.4 Gii php lp t thit b iu khin thanh rng nhin liu.

iu chnh thanh rng nhin liu ng ngha vi vic iu chnh hnh trnh

c ch ca piston bm cao p, t dn n vic nhin liu vo ng cao p, ti viphun nhiu hay t.

H. 2-10. S nguyn l b iu tc s dng thit b iu khin thanh rng

nhin liu

1 Bn p ga: 2 Thanh rng nhin liu; 3 Tay n; 4 Qu vng ; 5 -Khp trt; 6 L xo; 7 - Khp ni; 8 - Khp ni; 9 - Khp ni; 10 - Cn iu

khin

Nguyn l hot ng: khi ng c chy nhin liu LPG, lng du diesel

phun vo ch cn mt lng nh. Ta tc ng vo c cu iu khin 10 ko tay n

7 n khp vi khp 9 ng thi ct hn b iu tc ca ng c, thanh rng nhin

liu 2 dch chuyn qua tri lm cho hnh trnh c ch ca piston bm cao p ngn

li, du diesel ti vi phun t hn. Khi ng c chy diesel, nh c cu iu khin10, tay n 7 n khp vi khp 8, ko thanh rng nhin liu tr v v tr bnh

thng, b iu tc nhiu ch ca ng c hot ng b nh thng theo chc

nng ca n.

Nhc im ca phng php: vi khng gian c hn ca ng c vic lp

t thm mt c cu iu iu chnh thanh rng nhin liu tr nn kh khn.

chnh xc, tin cy km, c th lm hng b iu tc nu c cu iu khin khng

ngt b iu tc dt khot. Cc chi tit trong c cu i hi phi nh gn , chnh

xc.


71/100

- 69 -


2.3.1.1.5 Gii php s dng h thng nhin liu kiu tch phun.

H. 2-11. S h thng nhin liu kiu tch phun

1-Bm ngn ko 6- Cn y2-Trc lch tm 7- Trc iu chnh3-Bnh tch t 8- Cam4-L xo xupap 9- Hp xupap5-Xupap phn phi 10- Vi phun


72/100

- 70 -


Nhin liu c nn trong bm cao p ri c cung cp cho cc b nh tch

phun. Thi im bt u cung cp nhin liu vi phun c xc nh vo lc

trit tiu khe h gia u mt trn ca cn y v ui xupap. Lng cung cpnhin liu chu trnh c iu chnh bng trc iu chnh 7, khi mun h thng

nhin liu lm nhim v phun mi hay lm nhim v phun diesel bnh thng, ch

cn tc dng vo trc ny. Trn trc c c cu lch tm dng iu chnh lng

cung cp nhin liu chung cho tt c cc xylanh. Khi ta quay trc 7 i mt gc xc

nh no th khe h gia con i v ui xupap s thay i, do vy thi gian

nhin liu t bnh tch t cung cp cho vi phun cung thay i theo. Thi im bt

u cung cp nhin liu c thay i cng vi thi im kt thc cung cp (vi tr

s thay i nh nhau) nh mt cam i xng c nng ln nht trng vi v tr

piston im cht trn.

kim tra p sut nhin liu trong h thng, ngi ta lp vo hp xupap

mt ng h o p sut. Trong hp c nhiu loi xupap khc nhau: xupap x, xupap

bo him, xupap ng, m h thng.

u im: c th iu chnh lng nhin liu diesel phun mi vo bung tnhiu hay t nh mong mun.

Nhc im:

- Mi vi phun cn lp t mt xupap phn phi

- Phi lp t thm mt trc cam m xupap phn phi v mt h thng truyn

ng n cam, nhm xc nh thi im m xupap ny.

Kt lun: gii php ny ch nn p dng ch to ng c hon ton mi,

c cng sut ln. nu p dng ci tin trn xe but t mang tnh kh thi do phi

lp t thm nhiu c cu lm cho ng c tr nn cng knh, phc tp, chi ph

chuyn i cao


73/100

- 71 -


2.3.1.1.6 Gii php lp t h thng phun nhin liu mi song song vi h

thng phun nhin liu diesel c sn.

H. 2-12. S h thng phun nhin liu mi song song vi h thng nhin

liu diesel

Cu to v nguyn l hot ng: h thng cung cp du diesel trn ng c

c chia lm hai h thng ring r, mt cho hot ng ca ng cch s dng

diesel v mt cho hot ng ca ng c s dng LPG v diesel lm nhin liu

phun mi.

Nhin liu diesel phun mi u tin c cung cp n b phn bm, bao

gm b nh lc, iu ho p sut v mt bm phun nhin liu mi loi piston dnng bng in. Bm phun nhin liu mi lm p sut nhin liu mi tng nn xp

x 1000 bar. Nhin liu sau khi phn b qua h thng ng cung cp chung c p sut

cao n vi phun trn np xylanh. Thi im v khong thi gian phun nhin liu

mi c iu khin bng in.

H thng cung cp nhin liu diesel thng thng, bm cao p c dn

ng bng cam. T bm cao p, nhin liu c p sut cao i n l xo ti ca vi

phun, tt c c thit k theo tiu chun ca ng c diesel.


74/100

- 72 -


u nhc im ca gii php:

H thng lm vic vi tin cy cao, mang tnh hin i. Gii php ny ch

nn p dng ch to ng c hon ton mi, nu p dng ci tin trn xe butt mang tnh kh thi do phi thay i v lp t thm nhiu b phn v h thng in

iu khin bm phun nhin liu mi t tin v vy gi thnh chuyn i s cao.

2.3.1.1.7 La chn gii php phun mi

Qua phn tch 5 gii php k thut ci hon h thng nhin liu diesel h

thng c kh nng thc hin chc nng phun mi nhin liu c c trnh by

trn, ti la chn gii php k thut lp t thit b iu khin lu lng du trn

ng thp p gia bm cao p v bnh lc tinh, lp t trn ng c D6BR s

dng trn xe but thnh ph Nha Trang. Gii php ny ph hp vi cu to ca loi

ng c D6BR, mang tnh hin i v tin cy cao, ng thi chi ph lp t so

vi cc gii php khc thp, t phi thay i kt cu ban u ca h thng nhin liu

v vy khch hng s cm thy hi lng hn.

2.3.1.2 Gii php k thut lp t h thng cung cp LPG trn ng c

Cho n nay, h thng phun nhin liu kh vo ng np nh chnkhng ti c gp np c dng ph bin nht. Tuy nhin, nhng h thng phun

nhin liu mi ang c nghin cu p dng th hin nhiu u im hn, c bit

l h thng phun nhin liu dng kh ho lng ngay trc soupape np. H thng

ny c u im l ngn chn s bc chy ca hn hp trn ng np, hiu sut ca

ng c c nng cao v mc pht nhim gim i r rt.

LPG c th cung cp cho ng c dng kh hay dng lng. u im ca

vic s dng LPG di dng kh l s ng nht hon ton ca hn hp gas-khng

kh v trnh hin tng t thnh ng np bi nhin liu lng, hin tng ny rt

nhy cm khi ng c khi ng v khi ng c lm vic ch chuyn tip.

iu ny cho php gim c mc pht sinh nhim. Nhc im ca vic

cung cp dng ny l qu trnh iu khin di v s cung cp gas lin tc lm hn

ch kh nng khng ch t l khng kh / gas. c bit l giai on qu ca ng


75/100

- 73 -


c. Cng cn nhn mnh thm rng cng sut ng c gim i khong 8% do tn

tht lng khng kh np do kh gas chim ch.

H thng cung cp LPG bng cch phun dng lng cho php s dng uth ca LPG hn ch nhng nhc im trn y. u im ca vic phun LPG

lng l to kh nng kim sot c m c mi ln phun vi thi gian rt

ngn v vy c th p dng cc bin php hu hiu nhm gii hn mc pht

nhim khi ng c lm vic ch qu . S bc hi LPG lm gim ng k

nhit kh np do lm tng h s np ca ng c. Mt khc, mng nhin liu

lng bm trn ng np khng ng k g so vi khi ng c lm vic vi xng.

iu ny thun li cho vic lm gim mc pht sinh HC.

Tuy nhin, vic s dng vi phun thay v hng khuych tn do lm gim thi

gian to hn hp v mt nhin liu cung cp dn n s khng ng nht ca

hn hp v do c nguy c lm tng nng CO trong kh x.


76/100

- 74 -


2.3.1.2.1 Cu to v nguyn l hot ng ca h thng cung cp LPG vi

phng php to hn hp LPG-khng kh kiu khuych tn.

a) Gii php k thut lp t hng khuych tn (hng venturi) gia c gp npv bnh lc khng kh.

Khi ng c ang t ch chy nhin liu diesel chuyn sang chy LPG

vi diesel lm chc nng phun mi th chn ga iu chnh lng nhin liu diesel

vo ng c cho ph hp vi ti ng c diesel khng cn tc dng. V vy ta cn

lp t thm mt s c cu khc ni vi chn ga iu chnh lng nhin liu

LPG vo ng c cho ph hp vi ti. thc hin c nhim v ny ta cn lp

t t mt hng khuych tn, trn c b tr bm ga, bm gi, mt l chy

khng ti di bm ga. Hng khuych tn ny c lp t gia c gp np ca

ng c v bnh lc khng kh.

thc hin vic lp t ny ta c th s dng mt trong hai phng n.

Th nht, s dng nguyn mt b ch ho kh c ca ng c no c cng sut

tng ng. Phng n th hai l ch to mt hng khuych tn hon ton mi.

ch ng trong cng vic, khi mt cng t m kim ch ho kh c ph hp vicng xut ng c, trnh cng knh, to m quan ch lp t thm hng khuych

tn. Ti chn gii php ch to mt hng khuych tn hon ton mi.

H. 2-13. Cu to hng khuych tn

1- Bm ga; 2- L chy khng ti


77/100

- 75 -


b) S h thng cung cp LPG.

H. 2-14. S h thng cung cp LPG

1- Bnh cha LPG; 2- Van an ton; 3- Van chn; 4- Bnh lc; 5 - B gim

p-ho hi; 6 - ng mm; 7- Van an ton; 8- Van in t; 9 - ng khng kh

vo; 10 - B trn; 11 - ng gp np; 12 - Bung t; 13 Cm np - xut; 14- ng

dn nc sau khi lm mt ng c i vo; 15- ng dn nc i ra n Radiator

Kh ho lng LPG trng thi lng trong bnh cha c p xut t 6 8 bar,

di p sut ny khi m van chn 3, LPG lng c dn i theo ng ng cao p,

qua lc 4, n b gim - ho hi, ti y LPG lng c chuyn thnh hi vi p

sut gn bng p sut kh quyn. Sau theo k ht ng c, hi LPG c ht vo

b trn hn hp LPG - khng kh v i vo bung t. b gim p ho hi, qu

trnh gim p ho hi din ra rt nhanh v thu nhit rt nhiu gy ra hin tng

ng bng trn thnh khoang. ng dn nc vo 14 v ng dn nc ra 15 m bo


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cung cp mt lng nc sau khi i lm mt ng c ln tun hon trong

khoang b nhit ca b gim p ho hi chng li hin tng ng bng trn

thnh khoang.Cc van an ton 2 v 7 t ngt v ng mch LPG khi c s c. Van in t

8 dng ng hoc m mch LPG khi s dng.

c) V tr lp t b trn nhin liu LPG - khng kh.

Chc nng chnh ca b trn l to ra t l nhin liu LPG v khng kh

thch hp a vo bung t ca ng c. Lu lng kh np l mt trong nhng

thng s rt quan trng khi lp t b trn.

B trn nhin liu LPG lp trc bm ga

Cch b tr ny, hn hp c c trng bi s iu phi nhin liu LPG b

tc ng bi cc vt cn nh phn t lc gi, hnh dng hnh hc ca hng khuych

tn. Tuy nhin, c th thc hin vic dn nhin liu LPG qua mt l ngang ngay

trong hng khuych tn. Nh vy, hn hp nhin liu LPG - khng kh c tnh ng

nht cao. iu khin mt cch n gin lng hn hp vo bung t nh m

ca bm ga.

H. 2-15. S lp b trn LPG trc bm ga

1- Bnh lc khng kh ; 2- Hng khuych tn; 3- B trn; 4- Bm ga; 5- L

chy khng ti; 6- Bch ni vi c gp np

B trn nhin liu LPG lp sau bm ga.


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Thng tin v lu lng kh b trn c x l bi b bc hi l hm ca

ba thng s: p sut tnh tng i trong b nh lc khng kh, p sut tng i

trong hng khuych tn v sc ht ti trng ca ng c.

H. 2-16. S lp b trn LPG sau bm ga

1- Bnh lc khng kh; 2- Hng khuych tn; 3- Bm ga;

4- B trn; 5- L chy khng ti; 6- Bch ni vi c gp np.

La chn: Da vo nhng u nhc im ca hai cch lp t b trn

trn ti la chn gii php lp t b trn nhin liu LPG trc bm ga.

d) Cu to cc b phn trong h thng.

Bnh cha v cm np - xut (LPG Tank and Multi Valve)Nhin liu LPG trn t thng c nn trong b nh cha vi p sut

khong 10 bar. B nh cha nhin liu kh thng c dng tr v c 2 u h nh bn

cu. i khi b nh cha cng c dng h nh xuyn. Dng b nh cha ny ging ht

bnh xe, thng c s dng i vi ng c lng nhin liu v n c th t vo

khng gian ca bnh xe d tr.

Nhn chung, trng lng ca b nh cha ln v phi ch to bng thp dy

khong vi mm m bo an ton cho t v hnh khch c bit l khi xy ra tai


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ln. Ngy nay, trn th gii c mt s nc tin tin nh: Nga, M, Nht bt

u sn xut v s dng loi bnh cha LPG bng nha tng hp Plastic c li l

li thp. Loi vt liu ny rt nh d s dng v vn chuyn, nhng hin nay githnh tng i cao. Trc khi xut xng cc bnh cha LPG u phi qua th tc

th nghim, kim tra v chng nhn t yu cu an ton nh i vi cc loi bnh

cha c p sut cao thng thng khc. Php bnh cha LPG trn t phi qua

th nghim hai bc: bc u di p xut tnh 30 bar, bc th 2 th va chm

(50km/h v dng) p sut 11 bar trong bnh cha.

LPG c np vo bnh ti trm np, thng qua chi tit u np (Refulling

Point) c ch. Trn th gii thng thng c hai dng: vn vo bng ren hoc bng

cn p ni vi ng ng np ca trm np, khi np LPG ch c php np vo

80% dung tch bnh cha, phn th tch cn li d tr cho p sut bo ho ca

pha hi c th c, do nh hng ca nhit bn ngoi.

H. 2-17. Thng nhin liu LPG

Trn ng np vo cn c van ngc v van kho bng tay. Van ngc c

tc dng ch cho gas i theo mt chiu vo bnh m khng cho gas thot ra bng

ng np ny. Van kho tay c tc dng ng ca np mt cch ch ng, rt cn

thit trong trng hp cn bo dng van ngc v u np c ch, chi tit ny

c ch to trn mt cm. Cng trn cm ny c ng xut gas ra khi bnh cha

v c cc van an ton nh: van x t ng khi gas np vo y qu mc cho php

hoc s tng qu p sut bo ho hi do nhit tng t ngt, van ng t ng

khi dng gas thot ra vi tc nhanh (khi xy ra s c), van kho bng tay ng


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xut gas ra khi bnh c th c lp gas lng trongb nh khi cn sa cha bo

dng h thng. Cc chi tit ny c ch to trn chung mt cm gi l cm np -

xut nhin liu LPG.Cm np xut thng c hnh trn v ch to cng mt ng h ch th mc

LPG lng trong b nh. N c chia thnh cc mc 01/42/43/44/4. Cm

np xut ca tt c cc hng u c bo v trong hp st kn, c mt knh trong

sut c ch th mc LPG pha lng trong bnh. Np hp c th tho c v c

g t roong cao su cho kn, trong hp ny c ng dn gi vo v dn gi ra

c lp. ng thng gi ra c a xung gm xe, phng trng hp c r

r cm np xut hoc nhng git LPG c th ng li hng np sau mi ln np

LPG, c gi thi ra ngoi v khng tch t trong khoang hnh l ca xe gy nguy

him.

H. 2-18. Cm van np xut ng dn LPG p sut cao.

ng ng dn LPG t b nh cha n b gim p ho hi l ng ng

chu p sut cao ti a n 2,4Mpa, nn thng n c ch to bng ng thau c

ng knh t 6 8 mm. N c th c un cong cho ph hp vi yu cu s

dng. ng ng c lp t di gm xe, cch xa ng ng x ca xe.

B gim p - ho hi(Pneumatic LPG Reducer)


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