Noi Dung Do an Tot Nghiep

7/28/2019 Noi Dung Do an Tot Nghiep

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Khoa c kh ng Lc - Trng HSPKT Hng YnMc lc

Mc lc....................................................................1

Li ni u.......

4ChngI.Khi qut chung hot ng ca cm chi tit,

thng s dng cht lng trn xe..5

1.1.H thng nhin liu ...

5

1.1.1 H thng nhin liu xng..

..51.1.2 H thng nhin liu dng Diesel ..

..6

1.2 H thng lm mt ng c..

...7

1.3 H thng bi

trn...................................................................................7

1..3.1 Bi trn ngc.............................................................................................7

1.3.2 Bi trn hp s v cu truyn lc

chnh..8

1.3.3 Cm,chi tit s dng m bi

trn....9

1.4 H thng dng du tr lc.

....91.4.1 H thng phanh thu lc v c cu ct ly hp thu

lc..9

1.4.2 H thng tr lc

li...................................................................................................10

1.5 H thng iu ho dng mi cht

lnh10

Chng II Nhinliu...................................................................11

n tt nghip

1


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Khoa c kh ng Lc - Trng HSPKT Hng Yn2.1 Nhin liu

Xng...................................................................11

2.1.1 Cng dng chnh cha nhin liu

Xng11

2.1.2 Thnh phn chnh caXng.11

2.1.3 c tnh, ch tiu, cht lng

xng...13

2.1.4 Phn loi xng

t................................................................................................18

2.1.5 Phm vi s dng

xng...........................................................................................242.2 Nhin liu

Diesel.....................................................................................2

6

2.2.1 Cng dng ca du Diesel

..26

2.2.2 Thnh phn ho hc ca nhin liu Diesel

262.2.3 c tnh v ch tiu cht lng du Diesel

..28

2.2.4 Phn loi du

Diesel..................................................................................................31

2.2.5 Yu cu K thut nhin liu Diesel..

31

2.2.6 c tnh, chng loi du Diesel trn th tr-ng32

Chng III Du, m bitrn..........................................................................................353.1 Du bi trn

............................................................35

3.1.1 Cng dng chnh ca du bi

trn.. 35

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2


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Khoa c kh ng Lc - Trng HSPKT Hng Yn3.1.2 Thnh phn ca du nhn.

36

3.1.3 c tnh, ch tiu cht lng du

nhn 40

3.1.4 Phn loi du bitrn ............................................................................................. 43

3.2 M bi

trn..................................................59

3.2.1 Cng dng ca m bi trn.

..59

3.2.2 Thnh phn m bi

trn603.2.3 c tnh vc ch tiu cht lng m bi

trn61

3.2.4 Phn loi

m.............................................................64

3.2.5 Nhn hiu v yu cu k thut m..

..66

Chng IV Du thulc.........................................................................704.1 Cng dng ca du thu

lc.70

4.2 Thnh phn du thu

lc..70

4.2.1 Thnh phn

gc.du..................................................................................................70

4.2.2 Thnh phn cc cht ph gia

...70

4.3 c tnh v ch tiu cht lng du thu

lc71

4.4 Phn loi du thu

lc..................................................................................................71

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Khoa c kh ng Lc - Trng HSPKT Hng Yn4.4.1 Du

phanh..............................................................................

...71

4.4.2 Du tr lc li v thit b nng...

...724.5 Yu cu, c tnh k thut ca mt s du thu lc

..72

4.5.1 Cc loi du thu lc th trng Vit Nam..

..72

4.5.2 Ch tiu cht lng mt s loi du.

74

Chng V Dung dch lmmt..................................................................... ..775.1 Cng dng ca dung dch lm mt.

77

5.2 Thnh phn v cng dng ca dung dch lm

mt...77

5.2.1Dung mi n-

c..................................775.2.2 Cht chng

ng.......................................................................................................

77

Chng VI Hn hp lm lnh...79

6.1 Mi cht

lnh...796.1.1 Cng dng ca mi cht lnh

..79

6.1.2 Yu cu mi cht lnh

79

6.1.3 K hiu mi cht

lnh...............................................................................................79

6.1.4 Thnh phn v c tnh mi cht lm lnh ..80

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Khoa c kh ng Lc - Trng HSPKT Hng Yn6.2 Du bi trn mi cht

lnh..82

6.2.1 Quan h gia du bi trn v mi cht

lnh.82

6.2.2 Chng loi v c tnh du bitrn..........................................................................82

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Khoa c kh ng Lc - Trng HSPKT Hng YnChng VII Hng dn s dng v nh hng ca cht lng dngtrn t847.1 Hng dn s dng.

.84

7.1.1 S dng nhin liu.....84

7.1.2 S dng cc sn phm du, m.

84

7.1.3 S dng du thu lc.

84

7.1.4 S dng hn hp lm

lnh847.1.5 S dng dung dch lm mt ng

c.85

7.1.6 Mt s quy nh v thay th cht lng trn xe

.85

7.2 nh hng cc cht lng ti con ngi v mi tr-

ng86

7.2.1 An ton phng chngc.86

7.2.2 nh hng ti mi trng.

87

Ph lc......89

Ti liu tham kho,,

.91

n tt nghip

6


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Khoa c kh ng Lc - Trng HSPKT Hng YnLi ni u

t l phng tin giao thng c s dng ph bin v c ng.

Trong nhng nm gn y, nhu cu v s pht trin cc loi t ngy

cng cao, cc yu cu k thut ngy cng a dng. Cc loi t c s

dng ch yu trong cng nghip, nng nghip, giao thng vn ti.

Khong 20 nm ngn y t c bc ci tin r rt. Yu cu vn

hnh, sa cha, bo tr ng c i mi i hi phi hiu bit su

sc v cu to, c tnh k thut, nguyn l vn hnh, v phi c k

nng thnh tho trong quy trnh tho lp, bo dng, chun on v

sa cha. Do nhiu cng ty v nhiu chng loi ng c t vi

cc yu cu c trng ring. Nhng v nguyn l, vn cn phi hiu

bit v quy trnh tng qut cho cc loi ng c t. Vic bo dng

v sa cha khng ch bo m thi gian vn hnh lu di, tit

kim chi ph, tng hiu qu s dng m cn bo m cc yu cu

ngy cng cao v sc kho ca con ngi v bo v mi trng.

Qua thi gian hc tp v nghin cu v chuyn ngnh c kh ng lc

ti trng HSPKT Hng Yn. Em c giao ti Khai thc v s dng

cht lng trn xe .

ti c trnh by i su v vn l thuyt, phn tch thnh

phn, tnh cht, chng loi v c tnh k thut ca nhng cht

lng. y l nhng hiu bit c bn nht v chng m mi ngi th

sa cha t cm phi lm vng cng nh s hiu bit chung v

nhng tc ng ca chng ti sc kho v mi trng sng, ang l vn

ngy cng c quan tm rng ri.

hon thnh ti ny em su tm ti liu trong v ngoi tr-

ng, nht l ti liu v trang Web ca cc cng ty sn xut cc loi du

ang lu hnh ti Vit Nam. Vi mc nh to ra mt ti liu tham

kho v mt s tay tra cu hu ch cho sinh vin khoa, chc hn ti

liu ny khng th trnh ni nhng thiu st do s hiu bit thc t

cng nh kinh nghim v trnh cn hn ch em li. Do em rt

mong c s gip ca cc thy c, ban b trong v ngoi khoa

ti ny c hon thin v thc s tr thnh ti liu tham kho

cn thit cho sinh vin trong khoa.

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Khoa c kh ng Lc - Trng HSPKT Hng YnEm xin chn thnh cm n thy o Ch Cng v cc thy c, bn

b trong v ngoi khoa tn tnh gip em hon thnh ti

ny.

Chng I. Khi qut hot ng chung ca cm chi tit, h thng

s dng cht lng trn xe1.1. H thng nhin liu1.1.1 H thng nhin liu xng

B phn chnh ca nhin liu dng ny l dng ch ho kh. Hotng da trn hot ng chnh p gia hng khuych tn v bungphao do vy xng c a ln t bung phao v b x nh bi dngkhng kh i vo v to thnh hn hp in y bung chy caxilanh ng c.

V tr cha xng trong h thng: Xng c cha ch yu ti bnhxng v c ht ln ch nh bm xng do vy bnh xng phi c ktcu ph hp vi tnh cht ca xng v kt cu lp ghp trn xe, bnhxng thng c dung tch vo khong (45 lt) (tu thuc vo tng loixe) ngoi ra xng c d tr mt lng nh trong bung phao nhm mcch d dng to hn hp khi hot ng nht l ch khi ng.

Xng c dn i trong h thng theo s sau:

n tt nghip

8

Xng

Hn hp

1. Hng khuych tn 4. Bm xng2. ng dn xng 5. Hn hp3. Bnh xng 6. Bm ga


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Khoa c kh ng Lc - Trng HSPKT Hng Yn

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1.1.1.2. H thng nhin liu dng phun xng in t

c im ca h thng ny l xng c phun trc tip vo canp ca xilanh, thng qua vi phun, vi phun ny c iu khin bimy tnh trung tm(ECU). ECU nhn tn hiu t cc cm bin nm cc v tr khc nhau trn ng c sau la chn ra mt chngtrnh thch hp. Xng c phun ra vi p sut vo khong(2,7 3,5kg/cm2).

Xng c dn i trong ng dn theo s sau:

1.1.2 H thng nhin liu DieselDu Diesel c c tnh khc hon ton so vi xng do vy h thng

nhin liu cung khc hon ton, b phn quan trng nht ca hthng l bm cao p v vi phun. p sut (135kg/cm2) v i ti viphun, du c phun trc tip vo bung t c p sut cao, nhin liuDiesel c cha ch yu bnh cha v bm trong thn bm cao pmt phn c cha trong ng dn.

Du c dn ti xilanh theo s sau:

1.2 H thng lm mt ng c

n tt nghip

10

4

3

2

8

97

1

6

5

1. Bnh nhin liu2. Bm thp p3. Bu lc4. Bm cao p5. B iu chnh phun

sm6. B iu tc7. Vi phun8. ng tuy 9. ng du hi

1. L van lt, 2. B iukhin in t, 3. L cngim chn, 4. Vi phunin t

5. Thng xng, 6. Bm, 7.Bu lc, 8. B iu chnhp sut, 9. Cng tc10. R le nhit thi gian,11. Vi phun khi ng,12. Cm bin nhit ng c13. Bm hn hp, 14. Van


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Khoa c kh ng Lc - Trng HSPKT Hng Yn1.2. H thng lm mt ng c

Do nhit ng c tng cao khi ng c hot ng. Nn trnh hin tng dn n, gy b kt ca cc chi tit hot ng trnng c c trang b h thng lm mt. H thng lm mt trn tthng dng l h thng s dng dung dch lm mt, v nhit cang c rt cao do vy dung dch lm my cn thit phi c nhit si tng i cao, khi xe hot ng thi tit lnh th dung dchlm mt khng c ng c nn dung dch cn c nhit ngc thp v kh nng lm vic nhanh chng. Dung dch lm mtlun c lu thng trong h thng v c tn nhit ra khng kh nhkt lm mt theo s sau:

1.3 H thng bi trn trn xe:

bi trn v lm mt mt phn cho cc c cu hot ng trn xenh:

- Trn ng c: C cu trc khuu thanh truyn, trc cam

xupap, pton xilanh- H thng truyn lc: Hp s, cc ng, cu.- H thng l i: Trc v l ng li, cc khp chuyn ng ca c cu

li....Cc nh ch to thng s dng du bi trn hoc m bi trn.

1.3.1 Bi trn ng c:

Khi ng c lm vic trong ng c c rt nhiu cc chuynng khc nhau nh: Chuyn ng quay ca trc khuu, chuyn

ng tnh tin ca piston, xu php, quay ca trc cam, va p ca cm, Nhng chuyn ng ny to ra ma st ln, cng vi s dn nca vt liu cu thnh cc chi tit. D dn n cc hin tng nh kp

n tt nghip

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HTLM bng n-c c-ng bc

1.Thn my2.Np xilanh

3.ng nc rakhi4.ng dn bt nc ng c.5.Van hngnhit6.Np kt nc7.Kt lm mt8.Qut gi

9.Puli10.ng nc ni

tt v bm11.ng ncvo ng c12.Bm nc13.Kt lmmt du14.ng Phnphi nc


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Khoa c kh ng Lc - Trng HSPKT Hng Ynxu pp, lt bc, b piston do vy cc chuyn ng ny cn thitphi c du bi trn lm gim ma st v tm nhit. Du c bmht t y cc te y qua mch du trong h thng v i ti nhngv tr chuyn ng nh hnh v:

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1.3.2 Bi trn hp s cu truyn lc chnh

Hp s, cu truyn lc chnh c tc dng bin i mmen, t truyn t ng c ti bnh xe. Cu to chnh ca hp s, cu chdng chnh l cc cp bnh rng n khp theo tng t s truyn khcnhau di dng rng thng, xon. Trong hp s cc s c gi nh ccu gi s.

Cc bnh rng truyn mmen, tc cho nhau nh n khp tipxc do vy gia chng sinh ra lc ma st trt rt ln, lc ma st nytng ln theo tc v ti trng ca xe, nn nhit lng v mi mnca chng ngy cng tng. hn ch tnh trng ny trong hp sv

cu c dng du bi trn c nht ln v chu c nhit cao.

1.3.3 Cm, chi tit s dng m bi trn

M c tc dng tng t du bi trn nhm bi trn cp chi titma st ch yu nhng v tr m du bi trn khng c kh nnghay kh khn trong vic bi trn nh cc v tr sau:

n tt nghip

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1 2 3

4

5

61. y cc te2. Bu lc3. Trc khuu4. Trc cam5. ng du

chnh6. Trc n ghnh

cu li

C culi

Khp bntrcKhp bntrc

V tr bi trnbng m

V tr bi trnbng m


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1.4. H thng dng du tr lc

Trong cc i xe hin i h thng dng du ch lc bao gm:

Phanh thu lc, c cu ct li hp thu lc, h thng tr lc li.1.4.1 H thng phanh thu lc v c cu ct ly hp thu lc

H thng phanh thu lc v c cu ct ly hp thu lc c trangb hu ht trn cc loi xe c trng ti va v nh hin nay. Kt cuchnh ca h thng ny bao gm: Xilanh chnh nhn lc t chn ng-i p truyn n xilanh con bnh xe, ly hp thc hin qu trnhphanh v ct ly hp thng qua ng dn tuy. Du truyn lc bngcch tng p do vy du phi c c tnh nh: Tnh lu ng cao, chu

lc tt, .Du c cha ch yu trong bnh, c lp trn xilanh phanhchnh v thng xuyn lu ng khi phanh v ct ly hp theo s hthng sau:

n tt nghip

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Trc ccng

V tr bi trnbng m

H thngtreo

V tr bi trnbng m

1. Cn p phanh

2. Bu tr lc chn khng

3. Xilanh phanh chnh

4. Bnh du phanh

5. a phanh6. Van iu tit lc

phanh

1

2

3

4

5

1. Cn p ly hp

2. Bnh cha du

3. Cm Piston, xilanhchnh

4. ng dn

5. Cm Piston, xilanh con


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Khoa c kh ng Lc - Trng HSPKT Hng Yn1.4.2 H thng tr lc li

tng t s truyn ng li hay gim lc tc dng vo vnh tayli. Hu ht trn tt c cc loi xe u s dng h thng tr lc li th-ng l bng thu lc. B phn chnh ca h thng l bm tr lc, cmvan phan phi, cm piston xilanh lc.

Nguyn l hot ng: Khi xoay vnh tay li, n quay ng(tr li)tc ng ln cm van phn phi, van ny s iu khin phn phi psut thu lc vo mt ny hay mt kia ca piston trong xilanh lc.

Thng qua c cu l i lm bnh xe quay theo s iu khin ca ngili. h thng ny cng dng chnh ca du l truyn lc, do vy duphi c c tnh lu ng cao, chu nn tt, t chu bt, chng nmn

Du c lu thng trong h thng theo s sau:

1.5 H thng iu ho dng mi cht lnh

iu ho khng kh trong bung li ca ngi li cng nh trongkhoang hnh khch. Hu ht trn cc loi xe du lc hin nay u lph thng iu ho khng kh. Hot ng ca h thng da trn hin

tng bin i trng thi ca mi cht lnh. Mi cht lnh bin i tth lng thnh th kh do mi cht lnh phi thu nhit sau thkh c nn li nh my nn v tn nhit chuyn thnh th lng.

Mi cht lnh lu thng trong h thng theo s sau:

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PistonCung rng

Xilanh

Cm van iu

khin

Bung du B

Bung du A

ng ng dn

Bnh cha

Bm du 1 23

45

6

789

A. My nn cn gi l lc

lnh .

B. B ngng t, hay gin

nng.

C. Bnh lc/ht m hay

fin lc.

D. Van gin n hay van


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Chng II. Nhin liu

2.1. Nhin liu Xng

Xng l mt cht lng trong sut, khng mu, thnh phn ch yul cc hp cht Hydrocacbon d bay hi, d chy mnh nu t trongkhng kh. Cc Hydrocacbon c chn ln vi nhau mi loi biu hinmt c tnh nht nh to ra mt nhin liu ph hp.

2.1.1 Cng dng chnh ca nhin liu xng

Tc dng chnh ca xng dng trn t l to thnh hn hp nhinliu ph hp khi ho trn cng khng kh, c ht v xilanh v b tchy sinh cng lm quay ng c.

2.1.2 Thnh phn ca xng

Xng l mt nhin liu c to thnh do qa trnh trng ct du m dovy thang phn chnh ca xng l cc gc du m d bay hi. Ngoira ci thin tnh cht ca xng ngi ta cho vo xng mt s cht

ph gia. Ngoi thnh phn gc u m xng cn cha mt lng tpcht nht nh do nguyn nhn khc nhau to thnh.

2.1.2.1. Thnh phn gc du m ca xng

Tu thuc vo cng ngh chng ct m cc xng thng phm to rac cc thnh phn v cht lng khc nhau, nhng thnh phn gc dum ch yu ca tt c cc loi xng gm cc nhm sau:

- Nhm gc Ankal chim ch yu l cc cht nh:Heptan (C7H16)

Octan n - octan: CH3 - CH2 - CH2 - CH2 - CH2 - CH2 - CH2 - CH3Izo octan: CH3 - C(CH3)2 - CH2 - CH(CH3 ) - CH3

- Nhm gc Anken nh:n - octen: CH3 - CH2 - CH2 - CH = CH - CH2 - CH2 - CH3Izo octen: CH3 - C(CH3)2 - CH=CH(CH3 ) - CH3

- Cc Hydrocacbon gc thm cha thnh phn rt nh, d b xyho, to cn.

Metybenzen Ankynbenzen

- Ngoi ra cn mt s hm lng nh ca rt nhiu hp cht khc nhau

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CH3

CH3 R

E. Van x pha cao p.

F. Van gin n.

G. B bc hi, hay gin

lnh.

H. Van x pha thp p.


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2.1.2.2. Thnh phn cht ph gia dng trong xng

Cht ph gia c a vo xng nhm nng cao tr s octan, chngbc chy b mt, tc nghn bugi, chng to keo, chng g, chng lnhb ch ho kh , chng to thnh cht lng cn trong ca np.

Trong hu ht mi trng hp mt hp cht ho hc s p ng cmt trong cc chc nng ny.

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Khoa c kh ng Lc - Trng HSPKT Hng Yn1. Cht ph gia chng kch n

Hp cht chng kch n c dng chng xng kch n trongng c t chy bng bugi. L tng nht l xng chy m v honton trong bung t ca ng c.Tuy nhin, xng c cu to bi hng trm gc Hydrocabon khc nhaunn vi gc Hydrocacbon s phn ng d di khi b nn v nung nngvi s c mt ca khng kh.

Sau khi bc chy phn trc bc chy lan rng trong bung t snn v lm nng hn hp khng kh, nhin liu pha trc n v tchy thnh phn Hydrocabon cn li to ra sng va p vi tn s caogy ra ting n gi l ting g . Ngoi vic to ra ting n, ng cb g to ra cng sut thp v t tit kim nhin liu.

Nhng yu t quyt nh n ting g:C ting g trong ng c hay khng do hai yu t quyt nh.Cht lng chng kch n (ch s octan) ca xng v ch s octan m

ng c yu cu.Ch s octan cao c th t c theo hai cch:a) Do qu trnh tinh luyn: Chng hn thay i cht xc tc chuyn t Hydrocac bon c ch s octan thp ln Hydrocacbon c chs octan caob) Dng cht ph gia chng kch n.Yu cu v tr s octan ca ng c thng ph thuc vo thit k

ca n v iu kin vn hnh ca ng c.- Ch Tetra etyl (TEL)Trong qu trnh chy ca hi xng trong bung t . C s to

thnh v tch t ca cc hp cht Peoxyt. Nhng cht ny l nguynnhn dn n kch n, khi nng ca chng t n mt gi trgii hn no . Do vy trnh hin tng kch n phi ngn chns to thnh cc hp cht Peoxyt .

Mt trong nhng cng vic c hiu qu r rt l pha vo xng mthn hp c tn l nc ch. Nc ch l tn gi n gin ca hn hplng c thnh phn l hp cht tetra etyl. Ch [pb(C2H5)] vbromnuaetan BrC2H5 hoc ibromnua etan(BrC2H5Br). Tc dngca(Tel) l ph hu cc hp cht peoxyt v ngn cn s tch lu chngtrong xi lanh do trnh c hin tng kch n. Nh vy(Tel) c tc

dng tng(TSOT) ca xng ln Bromnua etan hoc ibromnua etanc gi l cht li ko v chng gip cho mui ch sau qu trnhchy khng ng li trong xi lanh, piston, xuppm theo khi en xra ngoi nc ch c tc dng gim tnh kch n ca xng r rt. Xongn l cht c gy tn thng n h thn kinh ca con ngi. Vth nng cho php ca bi ch trong khng kh khng vt qu0,005mmg/cm3 . Cng do tc hi n mi trng kh do vy xng chang c dn thay th bi xng khng kh ch cht lng cao.

- Cc ph gia chng kch n cha xyDo yu cu bo v sc kho v mi trng sng nn xng pha ch

ngy cng hn ch c s dng v thay vo l xng khng ch.Trong cha cc ph gia lm tng tr s octan nh: Metanol (CH3OH),Etanol(C2H5OH), Metybutyl ete(CH3 - O - C4H9), Amyl ete (CH3 - O -

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Khoa c kh ng Lc - Trng HSPKT Hng YnC5H11).Nhng hp cht ny ngn cn s tch t ca Peoxyt, sn phnchy ca chng khng c nh ca nc ch.2. Ph gia cht chng xy ho

Cht chng xy ho cho vo xng chng to keo, keo xut hintrong xng khi cc gc Hydrocacbon kt hp vi xy hay kt hp vinhau, s to keo trong xng c quyt nh bi loi du th sn xutra xng, qu trnh tinh lc, qu trnh ct gi v s hin din cakhng kh v thi gian ct gi.

Khi keo hnh thnh n to cht nng nh sn du ph ln lm tcng ng nhin liu, gicl ch ho kh v c th lm cho van b ktcht. Do vy c th tng tnh xy ho ca xng bng cc cch khcnhau trong c cch thm vo trong xng mt lng hp cht ph giachng xy ho v Polyme ho cc Hydrocabon khng bn mc d cch hot ng ny khng r nhng cht xy ho c xem nh l ngiph xch trong phn ng ho hc v Polyme ho.

3. Cc cht chng rR v mi mn gy ra nhiu vn nghim trng trong thngcha, ng ng v h thng nhin liu ng c chng hn r cnch qu trnh vn hnh ng c do b tc bu lc v gicl ch hokh, ngoi ra ch cn mt mu nh r trong van kim ca ch ho khth c th lm cho bung phao y sau tc my do trn xng.

St v cc phn lng kim b r v n mn tng ln do mt phnnh nc v khng kh ho tan trong xng, nc c th vo trong hthng nhin liu ca ng c do s ngng t hi nc trong thng nhinliu hoc do ln vo cng vi qu trnh bm xng.

C mt vi loi hp cht Hydrocacbon d tan thng dng nh axtamin bo, ankylphospht.. . Hu ht nhng cht ny hot ng c ldo kim loi dc ph mt lp phim bo v rt mng gi cho mtngoi khng tip xc vi nc cng nh lp bo v ny m gip b chho kh khng b nng cn.4. Cc cht chng ng bng

C hin tng ng bng xen vo qu trnh vn hnh my l do -ng ng nhin liu hoc ch b bt xut pht t vic c nc trongnhin liu, trong qu trnh khi ng lnh di mc quy nh (-1 n-100C) vi m tng i cao 65% th hi lnh ca nhin liu bc

hi trong b ch ho kh v ng li gy tc mch xng.Hai loi chung ca cc cht ph gia chng ng bng b ch ho

kh v cht lm gim im ng v cht hot ng b mt cdng cho nhiu loi xng .

Cc cht lm gim im ng c coi nh l cht chng ng cungcp cht bo v lnh trong h thng ngui ca ng c. Nhng chtph gia chng ng ny bao gm cn glycol lm gim lnh do him ng lnh ca hi nc.

Nhng tc nhn hot ng b mt cung cp mt s bo v khc.Vi nhng tc nhn ny, cc thnh phn lm lnh c to thnh. Tuy

nhin cht ph gia cung cp mt cht bo v ngn cn thnh phnny khng kt dnh vi nhau hoc khng tp hp trn b mt kim loica b ch ho kh. Cho ln cc thnh phn lm lnh khng lm hi g

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Khoa c kh ng Lc - Trng HSPKT Hng Ynkhi i qua b ch ho kh v ng np. Cc cht ph gia ny l Amin,Amin hoc mui Amoniumphosphat,

5. Cc cht ty ra b ch ho khCc cht ph gi ty ra thng c dng ngn cn cht lng

ng v ly i cht lng ng c trong b ch ho kh. Nhngcht ty ra ny bao gm Amin, Aminphosphat Xut pht t ctnh ca cht hott ng b mt.

6. Cht ph gia to mu scMu sc c cho vo xng cho thy s c mt ca cc cht

chng n, lm tng v hp dn khi bn, cho thy c nhiu loi, nhiunhn hiu xng. Mu sc ca xng l mu ca cc hp cht hu c dtan Hydrocacbon c chn cho mu sc m chng truyn cho xng.

2.1.2.3 Thnh phn tp cht cha trong xng

- Thnh phn cht cn c to thnh do Hydrocacbon trong xng bxy ho, do cc cn bn, mt kim loi, bi lt vo trong qu trnhvn chuyn, ct gi.

- Mt s nhng cht v c nh lu hunh tn ti di dng lu hunh t dohoc dng sum fua.

2.1.3 c tnh v ch tiu cht lng xng2.1.3.1 Tnh bay hi v nh hng ca tnh bay hi ti ng cdng ch ho kh

A) Tnh bay hiYu cu xng phi c tnh bay hi thch hp. Nu xng bay hi qud s ho hi ngay trn ng ng dn gy hin tng ngn hi, lmxng phun ra ln bt do vy khng m bo xng cung cp chong c. Xng bay hi km, (kh bay hi) gy ln hin tng kh khing ng c, kh iu chnh, lng ph nhin liu do chy khnght, to mui than lm bn my, long du nhnTnh bay hi ca xng c nh gi bng ch tiu phm cht:

- Thnh phn im si- p sut hi bo ho

- T trng hay khi lng ring1. Thnh phn im siCh tiu ny c xc nh trong dung c trng ct tiu chun

ho. i vi xng cn xc nh thnh phn im si nh sau:- im si u- im si 10%- im si 50%- im si 90%- im si cui

a)im si u v im si 10%

c trng cho tnh khi ng my, kh nng gy nghn hi v haomn t nhin. im si u thp hn quy nh cng nhiu th xngcng d hao ht, s sinh nghn kh.

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Khoa c kh ng Lc - Trng HSPKT Hng Ynim si 10% cao hn quy nh cng nhiu, cng kh khi ng

my. i vi t vic khi ng my c lin quan n nhit khngkh v t10%v theo cng thc kinh nghim sau:

TMin=1/2 t10%v- 50,5Trong :

- tMin : Nhit ti thiu ca khng kh- t10%v : ct 10%

b). im si 50% biu th kh nng thay i tc ca my. Nuim si 50% cao qu quy nh th khi tng tc lng hi xng vomy nhiu nhng t chy khng kp do kh bc hi do my yu,iu khin my kh khn.c). im si 90% v im si cui biu th bay hi hon tonca xng. Nu im si ny ln qu quy nh th xng kh bay hihon ton gy hin tng pha long du nhn, lm my d b mi mncng nh lng ph nhin liu.

Trn c s ngha ca thnh phn im si cho thy cc loi xngphi c tnh bay hi ph hp. Theo quy nh im si u khng di30 400C. c th d dng khi ng ng c khi cn ngui. Yucu 60 700C xng phi bay hi c 10% th tch. d dng tngtc a ng c vo ch lm vic n nh, yu cu 115 1200C phi bay hi c 50%V. xng chy ht hon ton trongng c yu cu 180 1900C xng phi bay hi c 90%V v 195 2000C xng phi bay hi hon ton.Nu i vi mt loi xng thng phm, kim tra cht lng ban u

cho thy thnh phn ct t tiu chun quy nh. Nhng sau mt thi

gian vn chuyn bm, ht, bo qun, kim tra li thy thnh phnim si cao vt qu quy nh, suy on ra c th do mt thnhphn nh bay hi hoc do cc hp phn nhin liu nng nh du honhin liu Diezel ln vo. Khi nu xng ny tip tc chy my sgy nhiu tc hi nh trn.2. p sut hi bo ho

Tiu chun xc nh astm d 323, TCVN 5731 - 1993L p sut hi xng trng thi cn bng vi th lng trong bom

Ried o c ti nhit xc nh l 1000F.p sut hi bo ho l mt ch tiu v tnh bay hi cc loi xng.

Da vo p sut hi bo ho c th nh gi nhin liu v tnh khing, kh nng to nt hi, hao ht do bay hi trong bo qun vmc nguy him do chy. p sut hi bo ho cng cao th kh nngbay hi cng mnh do vy yu cu cc loi xng phi c p sut hi boho ph hp khng qu cao, khng qu thp.3) Khi lng ring

Tiu chun xc nh astm d 1298, astm d 941, TCVN 2691 - 78- Khi lng ring o bng g/cm3 hay kg/m3 l khi lng ca mt n vth tch.- T trng l t s khi lng ring ca mt cht nhit no so

vi khi lng ring ca nc 40C k hiu dt/4 trong t0C l nhit ti xc nh t trng, thng thng chn t trng tiu chun 200C khiu d20/4 hoc t trng tiu chun 150C k hiu d15/4.

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B) nh hng tnh bay hi ca xng ti tnh nng hot ng cang c dng ch ho kh.

1. Tnh nng khi ngKhi bt tia la in ho kh d bn la nht l t l ho chn m

= 12:1- 13:1, Khi khi tc ng c rt chm, khng kh v xngho chn khng tt, nhit b mt thnh ng np, xilanh,piston.rt thp, do ch c khong 1/10 1/5 xng c bay hi.Nu b ch ho kh c iu chnh thnh phn ho kh t nhtth ho kh thc t lc vo ng c rt nht (c bit l khi trilnh), rt kh bn la v khi ng v vy phi ng bm gi cung cp ho kh c thnh phn m 1:1 lm cho ho kh vo xilanhst vi ho kh tt nht lc y ch cn 8% xng phun vo bay hi l tng ng vi im bay hi 10%.

2. Hin tng nt hiNhin liu c im 10% cng thp cng d hnh thnh bt kh ,to thnh nt hi trn ng t thng cha ti ch ho kh khi tri nngkhin lu ng ca ng xng km linh hot lm ng c xng chykhng n nh tnh trng y d lm cho xe chy nhanh, ti trng lnt nhin dng li v dng hn do im si 10% khng th quthp, thng thng p sut bo ho khng qu 500mmHg. 3. Chy m my

Sau khi hki ng cn cho ng c chy chm i my m dn. xng ng trn thnh ng kp bay hi sau mi c th tng ti

dn cho ng c. Thi gian t lc khi ng ti lc tng ti l thigian chy m my. Th nghim ch ra rng: xng c im 20% - 50%cng thp th thi gian chy m my cng thp v tnh c ng cang c cng tt.

4. Tnh tng tcLc m bm ga t ngt lm ng c tng tc mc d c nhin

liu v khng kh i vo ch ho kh u tng nhng mt phn xngcha kp bay hi ng li trn thnh ng lm cho ho kh thc t ivo xi lanh long, gy nh hng ti tnh nng tc ca ng c.Nu nhit ca ng ng np ln m dng xng d bay hi, trong

ng c c s dng thit b tng tc c th lm cho ho kh mgy tc hi xu m tnh nng tng tc. Nhn chung mun cho ngc d tng tc cn dng ng c c im si 35 60% tng ithp. Thng thng ly im 50% lm tiu chun nh gi tnh tngtc.5. Tnh phn phi

Thc nghim ch ra rng khong 1/2 xng kp bay hi trn ngnp s m bo nhin liu phn phi u vo khoang xi lanh. Do im si 50% c ngha quan trng i vi cht lng phn phi xngvo xi lanh.

6. Tnh chy

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Khoa c kh ng Lc - Trng HSPKT Hng YnMun c cht lng chy tt trong ng c xng cn kp thi bay hi

ht trc khi bt tia la in do im ha sng m ca ho khphi rt thp im sng m li ph thuc vo im 90%. Nu im90% cao qu lm nhin liu chy khng kit, to khi en, trongbung chy c nhiu mui than. Nu im 90% thp qu s lm hokh vo xi lanh qu kh gy gim h s np, gim cng sut v gimkhuynh hng kch n.

7. nh hng ti du nhn trong y cc teNu tnh bay hi chung ca xng khng tt v nu im sng m

ca ho kh qu cao, xng c th nghng ng trn thnh xi lanh ltxung y cc te lm long v ph hng du nhn. Tnh trng nycng trm trng khi khi ng lnh v khi chy m my v vy im90% ca ng trng ct khng c cao qu. 8. nh hng ti cht lng hn hp kh np

Nu nhit ng lp thp s lm tng mt kh np do tnh

bay hi ca nhin liu cng tt.2.1.3.2. Tnh chy ca xng

1. Qa trnh chy ca xngQu trnh chy ca hi xng trong bung t l mt qu trnh chy

cng bc, thc hin c l nh tia la in ca bugi, qu trnh chynh vy l rt nhanh nhng khng phi xy ra tc khc trong ton bth tch xilanh m bt u chy t bugi sau lan dn ra ton bth tch xi lanh, lc chu trnh chy kt thc.

Trong qu trnh t chy hn hp trong xilanh xy ra hin tng chybnh trng v hin tng chy khng bnh thng.- Hin ttng chy bnh thng: Sau khi bu gi bt tia la in tc

lan truyn ca mng la l 20 25 m/s. vi tc nh vy p suthi trong xilanh tng u n, ng c hot ng bnh thng.

- Hin tng chy khng bnh thng: V mt l do no nh xngdng khng ngtiu chun k thutchng hn s gyhin tng chy khng

bnh thng nh hintng kch n tc lti mt im no trong xilanh, dmt cu la cha lanti nhng hi nhinliu bc chy tngt vi tc chylan truyn gp trm ln tc chy bnh thng do p sut trongxilanh tng vt ti khong 160kg/cm2 chnh s tng p sut t ngt

to ra mt sng hi xung ng va p vo vch xilanh v phtting ku lch cch, my n dung dt v nng hn bnh thng, lmgim p sut my, tiu hao nhin liu do chy khng ht, dn n

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Khoa c kh ng Lc - Trng HSPKT Hng Ynmn cc chi tit my, thm ch cn gy rn nt piston nn ng c hot ng bnh thng th xng phi c tnh chng kchn tt ph hp vi tng iu kin hot ng ca ng c bng cchdng loi xng ph hp vi t s nn ca ng c.

2. Bin php ci thin tnh nng chy ca ng cThc t cho thy qu trnh chy kch n ca ng c xng c lin

quan cht ch ti thnh phn ho hc ca xng. So snh cc nhmHydrocacbon cho thy Hydrocacbon n-parafin d b chy kch nnht ngc li nhm Hydrocacbon izo-parafin v Hydrocacbon thm khb kch n. nh gi kh nng chy kch n ca mt loi xng no ngi ta

pht minh ra mt phng php thc nghim da trn s so snh qutrnh chy vi cc loi nhin liu tiu chun t xc nh mt ch

tiu chun c tn l tr s Octan(TSOT). Tr s octan ca mt loi xngcng cao cng kh b kch n khi chy trong ng c v ngc li. Dovy ngn cn hin tng chy kch n xy ra ngi ta tm binphp nng cao ch s octan.3. Cc loi tr s octana). Tr s octan xc nh theo phng php Mt(Motor Octan

Number) k hiu l MON.- Tr s MON th hin c tnh ca xng dng trong ng c

trong iu kin hot ng trn xa l, tc cao nhng u nhoc khi ng c chuyn ch nng.

b). Tr s octan xc nh theo phng php nghin cu (RsearchOctan Number - RON). Tr s RON th hin c tnh ca xng dngcho ng c hot ng trong thnh ph, tc thp li hay phigim ga t ngt.

Cng mt mu xng, Tr s RON bao gi cng ln hn MON do vy khini tr s xng ca mt loi xng no cn phn bit l RON hayMON trnh nhm ln, hiu s ca ca hai tr s RON, MON biuth cho s thay i tnh cht ca xng. nhy cm ca mt loixng thp c nghi l loi xng t thay i kh nng chy trong cciu kin hot ng khc nhau ca ng c.

c). Tr s octan thng dng (Popullar Octan Number - PON). mt snc s dng PON bng trung bnh cng RON v MON c trngcho tnh chng kch n ca xng thay v dng RON hay MON ring r.

2.1.3.3 Tnh n ng ho hc ca xng- Tnh n nh kh xy ho ca xng biu th kh nng xng duytr c cht lng ban u trong qu trng bm ht, vn chuyn, tncha, bo qun. nh gi tnh n nh ho hc ca xng bng chtiu cht lng: Hm lng nha thc t v bn xy.

1. Nha thc tTiu chun xc nh astm d 381

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http://var/www/apps/conversion/tmp/scratch_5/Co%20so%20so%20sanh.dochttp://var/www/apps/conversion/tmp/scratch_5/Co%20so%20so%20sanh.dochttp://var/www/apps/conversion/tmp/scratch_5/TU%20LIEU%20CAN%20THIET/nhien%20lieu%20chuan.dochttp://var/www/apps/conversion/tmp/scratch_5/Co%20so%20so%20sanh.dochttp://var/www/apps/conversion/tmp/scratch_5/Co%20so%20so%20sanh.dochttp://var/www/apps/conversion/tmp/scratch_5/TU%20LIEU%20CAN%20THIET/nhien%20lieu%20chuan.doc


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Khoa c kh ng Lc - Trng HSPKT Hng YnL lng cn rn cn li sau khi lm bay hi mt th tch xng nht

nh, ti nhng iu kin nht nh bng cch thi dng khng khv hi nc nhit quy nh qua mu xng th nghim. c obng mg/100ml.

Xng mi c hm lng thc t nh hn xng tn cha lu ngy. Hmlng nha thc t tng ln l do di nh hng ca nhit , khng kh,kim loi.cc hp phn km n nh trong xng b xy ho to thnhnhng hp cht keo nha. Cc loi xng c tnh n nh ho hc khcnhau tu thuc vo thnh phn ho hc ca chng, xng c hm lngnha thc t nh th c n nh ho hc cng cao v ngc li.Hm lng nha ca cc loi xng khng c vt qu quy nh l 4-5mg/100ml ti ni sn xut v 8mg/100ml ti ni cha. Nu hm lngnha thc t vt qu quy nh s nh hng khng tt n ch tiucht lng khc ca xng nh tnh chng kch n, tnh n mn, tnh bayhi.

2. Tnh n nh xy hoTiu chun xc nh astm d 525Tnh n nh xy ho c o bng chu k cm ng, chu k cm

ng l khong thi gian o bng pht m trong xng khng xy ra skt ta v vn c khi b xy ho bi xy trong khng kh ti p sutv nhit thch hp chu k cm ng ca mu xng th nghim cngdi th tnh n nh xy ho ca xng cng tt. Nu xng c boqun trong trng hp khng tt, b bin cht th chu k cm ng stng ln. Theo quy nh chu k cm ng ca xng khng vt qu 240pht.

1.1.3.4 Tnh n mn kim loi ca xng

Thnh phn ch yu ca xng l cc hp cht Hydrocacbon honton khng c tc dng n mn kim loi tuy vy trong xng c chamt s tp cht cha c loi b trit khi xng, hoc trong qutrnh tn cha, vn chuyn xng b nhim bn bi cc tp cht,nhng tp cht ny c tc dng n mn kim loi lm nh hng ti tuith hot ng ca my. Do cn kim nghim cc ch tiu cht l-

ng xng ny.

nh gi cc ch tnh n mn kim loi ca cc loi xng ngi ta sdng cc ch tiu sau y:

1. Hm lng lu hunh tng sTiu chun xc nh astm d 1266

c xc nh bng phn trm khi lng so vi mu xng (%kl). Theocc tiu chun Vit Nam quy nh lu hunh tng s trong cc loixng t khng vt qu (0,1 0,15 %kl).2. axt

Tiu chun xc nh astm d 794astm d 664

axt c o bng lng KOH trung ho lng a xt hu cc trong 100ml xng (mg/100ml).

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Khoa c kh ng Lc - Trng HSPKT Hng YnNgoi ra nh gi tnh n mn kim loi ca xng ngi ta cn xc

nh a xt, Baz tan trong nc trong cc loi xng

2.1.4 Phn loi xng t

phn loi xng thng phm dng cho t, xe my ngi ta phnloi chng theo ch s octan (TSOT).

2.1.4.1. Trn th trng th gii

Xng t xe my c phn lm ba loi: Xng thng, xng cao cp vxng c bit.1. Xng thng: L xng c RON t 92 tr xung v c s dng cho

cc li ng c xe ti, xe gn my c t s nn t 7 8,5, loi xngthng ny cng phn lm hai nhm c sn xut theo tiu chun khc

nhau ca tng nc, tng khu vc.Xng thng c RON t 90 92 c sn xut t thp nin 70 tr liy, thay th loi xng thng c TSOT thp hn (RON = 80 86).2. Xng cao cp(Super): L loi xng c TSOT t (93 - 100) s dng

thch hp cho tt c cc loi xe mt gn my i mi c t s nn t(8,8 - 10), tu thuc vo khu vc m c chia lm hai nhm:

- Xng cao cp c RON 98 100 c sn xut cc nc cng nghippht trin.

- Xng cao cp RON = 93 98 hin ang c sn xut ta cc khuvc Chu u v Chu .

3. Xng thng hngLoi xng ny c cht lng tt nht c dng cc nc cng nghip

pht trin, dng cho cc loi xe c t s nn t 10 tr ln.

2.1.4.2. th trng Vit Nam

Da trn tr s octan xng c chia lm ba loi sau:1. Xng thng: C tr s octan xc nh theo phng php nghin

cu, TSOT = 83 gi l xng ch 83.

2. Xng cht lng cao: C tr s octan xc nh theo phng phpnghim cu khng nh hn 92 gi l xng ch 92.3. Xng c bit: C TSOT xc nh theo phng php nghin cukhng nh hn 97 gi l xng ch 97.Hin nay xng ang c hn ch s dng rng ri .

Bng 2.1.1 Ch tiu cht lng xng ch.

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Bng 2.1.2 Ch tiu xng cao cp ca nht bn

Tn ch tiu Tiu chun Mc quy nh

1. Hm lng lu hunh (ppm) ASTM D 1266 Max 300,02. n mn mnh ng(3h/500C)

ASTM D 130 Max 1

3. Nha thc t(mg/100ml)

ASTM D 381 Max 4,00

4. Hm lng ch (g/l) Max 0,001

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Ch tiu Xng pha ch Phng php th

1. Tr s octan khngnh hn theo phngphp nghin cu

83 92 97ASTM D 2699

2. Thnh phn si phnon- im si u(00C,

khng ln hn- 10%V(00C), khng lnhn- 50%V(00C), khng lnhn- 90%V(00C), khng lnhn

- im si cui(00C),khng ln hn- Cn cui %V(00C),khng ln hn

-70

120190

210

2,0

TCVN 2698 95

3. n mn mnh ng 500C/3h, khng ln hn N01 TCVN 2694 954. Hm lng nha thc tmg/100ml, khng lnhn- Khi sn xut- Khitn cha, s dng

58

ASTM D 381 94

5. n nh xyho(min) khong nh hn 240

ASTM D 525 95

6. Hm lng lu hunhtng (%kl) khng lnhn

0,15 ASTM D 1266 95

7. Hm lng ch (g/l),khng ln hn 0,15 TCVN 6020 958. p sut hi bo

ho(Reid) 37,80

C(kPa). 43,8

TCVN 5731 93

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5. p sut hi bo ho(Psi/37,80C)

ASTM D 4935 6,04 9,25

6. Tr s octan- MON- RON

ASTM D 2700ASTM D 2699

Min 81,0Min 91,0

7. Hm lng olefin (%V) Max 25,08. Thnh phn im si- im si 800C

(%V)- im si 2000C

(%V)- im si cui (FBP)

(%C)

ASTM D 86Min 90,00Min 97,00Max 210,0

Bng 2.1.3 Tiu chun xng cht cao cp c ch ca TrungQuc

Tn ch tiu Tiu chun Mc quynh

Kt quc tr-

ng1. T trngd600F/600F

ASTM D1298

- 0,7188

2. Hm lng lu hunh(%kl)

ASTM D1266

Max0,10

0,005

3. n mn mnh ng(3h/500C)

ASTM D 130 Max 1 1


ASTM D 381 Max5,00

1,50

5. Hm lng ch (g/l) ASTM D3237

Max0,13

0,11

6. n nh xy ho(min)

ASTM D 525 Min480,00

480,00

7. p sut hi bo ho(Psi/37,80C)

ASTM D4935

Max 9,0 8,70

8. Tr s octan- RON ASTM D

2699Min 91,0 92

9. Thnh phn im si(0C)

- im si 10%V- im si 50%V- im si cui (FBP)

ASTM D 86Max70,0Max120,0Max

205,0

49,0100,0195,0

Bng 2.1.4 Tiu chun cht lng xng ca cc quc gia SNG

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Khoa c kh ng Lc - Trng HSPKT Hng Yn(Lin x c)

Tn ch tiu TiuchunGOST

Mc quy nhA-76 A-93 A-95

(1) (2) (3) (4) (5)1. Hm lng lu qunh(g/l) G.19121 Max 0,1 0,1 0,12. Nha thc t(mg/100ml)

G.1567 Max 3,0 5,0 5,0

3. Hm lng ch (g/l) Max0,013

0,013 0,013

4. n nh oxy ho(min)

G.4039 Min 1200 1200 900

5. p xutboho(kpa/37,80C)

G.1756 66,7-99,3

66,7-99,3

66,7-99,3

6.Tr s octan - MON- RON G.8226G.511 Min 76- 8593 85957. Axit tng(mgKOH/100ml)

G.5985 Max 1,0 0,8 2,0

8. Nc v tp cht c hc G.6370 Khng Khng Khng9. Axit v baz trong nc G.6307 Khng Khng Khng10. Thnh phn imsi (0C)

- im si u( IBP)- im si 50%V

- im si cui (FBP)

ASTM D86 Min 35,0

Max115,0

Max195,0

35,0115,0205,0

30,0120,0205,0

Bng 2.1.5 Tiu chun xng cao cp khng ch ca Trung Quc

Tn ch tiu Tiu chun Cao cp 93 c bit 95

1. Hm lng luhunh (%kl)

ASTM D 1266 Max 0,05 Max 0,05

2. n mn mnhng(3h/500C)

ASTM D 130 Max 1 Max 1


ASTM D 381 Max 5,00 Max 5,00

4. Hm lng ch(g/l)

ASTM D 3237 Max 0,001 Max 0,001

5. n nhxy ho (min)

ASTM D 525 Min 480,00 Min 480,00

6. p sut hibo ho(Psi/37,80C)

ASTM D 4935 Max 9,0 Max 9,0

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7. Tr s octan- RON ASTM D 2699 Min 92,6 Min 94,6

8. Thnh phnim si(0C)

- im si10%V

- im si50%V

- im sicui (FBP)

ASTM D 86Max 70,0Max 120,0Max 205,0

Max 70,0Max 120,0Max 205,0

Bng 2.1.6 Tiu chun cht lng thng c ch ca Philippin

Bng 2.1.7 Phm cht xng t khng c ch mt s nc trongkhu vc

Tn ch tiu Tn nc

Singapo Malaysia Thi lan Hongkong1. Tr s octan

- RON- MON

Min98Min86

Min97Min85

Min95Min84

Min98Min87

2. Hm lng ch (g/l) Max0.005

Max0.013

Max0.013

Max0.003

3. p sut hi bo ho(kPa/37,80C)

60 - 70 Max70 Max62 -

4. Hm lng lu hunh (%kl) Max 0,1 Max0,15

Max 0,1 Max0,05

5. n mn mnh ng Max Max Max Max N01

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Tn ch tiu Tiu chun Cao cp 93

1. Hm lng lu hunh (ppm) ASTM D 1266 Max 50,02. n mn mnh ng(3h/500C)

ASTM D 130 Max 1

3. Hm lng ch (ppm) M. 1026 Max 70.04. Mu sc ASTM D 156 Min +10,05. p sut hi bo hoRVP/1000F(Psi)

ASTM D 323 Max 6,8

6. Tr s octan- RON ASTM D 2699 Min 83,0

7. Hm lng cht thm(%V)

ASTM D 875 Max 50,0

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(3h/500C) N01 N01 N016. Hm lng MTBE(%kl)

Max15 Max15 5,5 11,0

-

7. Benzen(%V)

Max15 - - -

8. Thnh phn im s(0C)- im si 10%V- im si 50%V- im si 90%V- im si cui

Max74Max120Max190Max225




9. Thi k cm ng(min)

240 240 360 300

Bng 2.1.8 Mt s xng khng ch ang dn c lu hnh rngri ti vit Nam

STT Tn ch tiu Xng khngch

Phng phpth

90 92 95

1 Tr s Octan theo phng phpnghin cu (RON), khng nhhn

90 92 95 ASTM D 2699

2 Hm lng ch, g/l, khng lnhn

0,013 TCVN 6704:2000/(ASTM D 5059)/

ASTM D 3237

3

Thnh phn ct phn on- im si u, oC Bo co ASTM D 86- 10% th tch, oC, khng ln hn 70- 50% th tch, oC, khng ln hn 120- 90% th tch, oC, khng ln hn 190- im si cui, oC, khng ln

hn

215

- Cn cui, %th tch, khng lnhn

2,0

4 n mn mnh ng 50oC/ 3h,khng ln hn

1 TCVN 2694:2000/(ASTM D 130)

5 Hm lng nha thc t ( radung mi), mg/ 100ml, khng lnhn

5TCVN 6593:2000/(ASTM D 381)

6 n nh oxy ha, pht, khng

nh hn

240 TCVN 6778:2000/

(ASTM D 525)

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STT Tn ch tiu Xng khngch

Phng phpth

90 92 95

1 Tr s Octan theo phng php

nghin cu (RON), khng nhhn

90 92 95 ASTM D 2699

7 Hm lng lu hunh, %khilng, khng ln hn

0,15ASTM D 1266

8 p sut hi (Reid) 37.8 oC,kPa

43 - 80 TCVN 5731:2000/(ASTM D 323)/

ASTM D 49539 Hm lng benzen, %th tch,

khng ln hn5

TCVN 6703:2000/

(ASTM D 3606)10 Khi lng ring ( 15oC), kg/

m3Bo co

TCVN 6594:2000/(ASTM D 1298)

11 Ngoi quan Trong sut, khngc tp cht l lng

Kim tra bng mtthng

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Khoa c kh ng Lc - Trng HSPKT Hng Yn2.1.5 Phm vi s dng xng

Tu vo t s nn ca ng c lp trn xe m c s dng cc loixng khc nhau, da vo mi quan h gia t s nn ca ng c vtr s octan ca xng.

Vic la chn TSOT ca xng s dng ph thuc vo t s nn cang c. ng c c t s nn cao l i hi xng s dng phi ctr s octan cao. Nu dng loi c tr s octan thp s gy hin tngkch n. Nu dng loi xng c tr s octan cao hn yu cu cang c cng khng tt gy lng ph xng, ng c hot ngkhng n nh, d nng my. Hin nay trn th trng Vit Nam tnti cc loi xng nh: xng ch 83, 90, 92. Do vy trn nhng i l xngthng xng c pha chn to ra loi xng c tr s octan t 83 ti 90 vt 90 ti 92. Nu pha xng ch 90 vi xng ch 92 to ra loi xng ch90,9; 91...

Vi hai loi xng bn trn th trng hin nay l Mogas 90 v Mogas 92, cc xe gnmy c t s nn t 7:1 n 8:1 u c th hot ng mt cc trn tru nu m bo ccc thng s k thut khc nh: tnh trng sch s ca ng c, v tr cht la v thngs qun tnh vn hnh Run-on (Run-on l thut ng dng ch xu hng tip tchot ng ca ng c khi ngt ngun in bugi, nu qun tnh ny cng ln, ng ccng d b kch n).Dng xe cao cp ca cc hng xe hi danh ting nh Mercedes-Benz, GM Daewoo, Lexus, BMW ang hot ng Vit Nam, ng c c trang b hthng iu hnh t ng gm hai h thng th cp: H thng kim sot lu lng dngkhng kh, lu lng dng nhin liu, thi gian nh la bugi; v h thng cm bin cc

thng s nng oxy trong kh thi, mc kch n, nhit kh thi, nhit cht lmmt v nhit van np. Trong trng hp bn s dng loi xng c ch s Octan khcloi ang dng, h thng s lp tc a ng c v trng thi hot ng ti u nht ivi loi xng bng cch thay i thng s dng nhin liu, dng khng kh iuchnh hn hp xng-gi, ra lnh cho bugi nh la sm hay mun ( nh la sm t lthun vi ch s Octan, 60 i vi xng 93, 80 vi xng 96 v mun 40 vi xng 91).Tuy nhin, trn thc t, vn c mt gi tr v ch s Octan ti u dnh cho tng loi ngc tng iu kin vn hnh nht nh, gi tr ny thng c cc nh sn xut a ra,v vy bn cn phi tn trng cc khuyn co v cn trng vi nhng quyt nh camnh. Nu loi nhin liu s dng c ch s Octan ng nh yu cu, bn cng khng

nhn c nhiu nng lng hn so vi s dng loi nhin liu c ch s Octan cao hn.ng c ang vn hnh trn tru iu kin ti u, v th, mt nhin liu c ch s Octancao hn s chng c nh hng ng k no n hot ng ca chng. Hn na, khi shu mt chic xe c trang b nhng h thng hin i nh vy, bn cn phi lu rnghai yu t cng sut ng c v s dng nhin liu mt cch kinh t c vai tr ngangnhau. Nhin liu c ch s Octan cao hn ng nhin s t hn, v nh vy bn s

phi chi nhiu tin hn. Cn nu nhin liu c ch s Octan thp hn ch s Octan ti ukhng ng k th vic bn s dng nhin liu c ch s Octan cao hn s lm cho hthng iu hnh t ng chuyn v iu kin vn hnh ti u, lc ng c ca bnkho hn, ng thi vn kinh t cng c ci thin. Li khuyn cui cng l bn nn

thay i ch s Octan cc ma khc nhau (chn loi xng c ch s Octan thp hn vma ng) tit kim tin m khng lm gim sc mnh ca ng c.

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Khoa c kh ng Lc - Trng HSPKT Hng Yn Thun tin trong qu trnh s dng cc nc ty u v LinX c a ra quy nh tng quan gia t s nn vi tr s

Octan nh sau:

Bng 2.1.9

A. Quy nh ca Ty uTn nc T s nn ca ng c Tr s Octan

Min Max Min MaxAnh 8,0 10,5 78,5 101,5Php 7,8 10,5 80,5 98c 7,8 11,0 82,5 101,0

Italia 8,1 9,5 84,0 102,0

Bng 2.1.10

B. Quy nh ca Lin Xng c Xng

ng kchXilanh

T s nn MON RON

100 9,0 89 95100 8,5 89 9576 8,8 85 9892 6,6 72 -92 7,65 85 9382 9,0 85 9376 7,0 72 -76 7,0 76 -72 6,5 76 -82 6,2 66 72 -

Bng 2.1.10

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Mt s loi Xng cao cp khc

T s nn Ch s octanti u T s nnCh s octan

ti u

5:1 72 9:1 966:1 81 10:1 100

7:1 87 11:1 104

8:1 92 12:1 108

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Khoa c kh ng Lc - Trng HSPKT Hng Yn2.2 Nhin liu Diesel2.2.1 Cng dng ca du Diesel

Du Diesel l loi nhin liu c to thnh t qu trnh tinh ch dum, c to ra t du nng hn sau khi rt xng ra.

Cng dng ch yu ca du Diesel l lm nhin liu t chy chong c c t s nn cao, gi l dng c Diesel. c im khc vixng l du Diesel c kh nng t bc chy trong khng kh c psut, nhit cao.

2.2.2. Thnh phn ho hc ca du Diesel

Thnh phn ch yu ca nhin liu Diesel dng cho ng c tbao gm:

- Thnh phn gc du m.

- Thnh phn cht ph gia.- Thnh phn tp cht.

2.2.2.1. Thnh phn gc du m

Thnh phn gc du m l hn hp phc tp ca cc nhmHydrocacbon khc nhau, bao gm cc nhm sau:

- Hyrocabon mch thng(cc ankal) ch yu l thnh phnXetan (C16H34)(C kh nng t bc chy cao), Decan (C10H20)..

- Hydrocacbon no mch vng Alkyl Cycl

- Thnh phn Hydrocacbon thm thuc loi benzen, c kh nngt bc chy thp, gm cc nhm:

Metyl benzen. (C6H5- CH3)

Alkyl bezen. (C6H5- R)

- Ngoi ra cn mt s Hydrocacbon khc vi hm lng nh cngnh hng phn no n tnh cht ca du.

2.2.2.2. Thnh phn cht ph gia

l cc cht ho hc b xung vo nhin liu vi hm lng nh ci thin mt vi tnh cht khai thc ca du Diesel. Trong qu trnh

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R

CH3

R


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Khoa c kh ng Lc - Trng HSPKT Hng Ynnghin cu, sn xut v ng dng ngi ta to ra nhiu cht ph giakhc nhau. Di y l mt s cht ph gia c dng ph bin:1. Cht tng cng t bc chy. Lm tng ch s Xetan ca nhinliu cht ph gia ny bao gm cc ete nitrit ca mt s ru(ankol).ng ng Propi Nitorat, Xyclohekxyn, Nhng cht ny km nnh, l ngun to ra cht t do.2. Cht ph gia chng xy ho: gim hay ngn nga kh nngxy ho ca nhin liu ngi ta dng cc hp cht ca Fenol.3. Cht ph gia n nh: Cht ny ngn nga s nng ng nctrong nhin liu khi bo v n. Cht ph gia c s dng l cc Aminmch thng, Cao phn t v mt s cht ng phn mch thng.4. Cht ph gia chng ng c: Cht ny lm gim nhit ng c ca nhin liu, cht ph gia c dng l sn phm ngtrng hpEtylen Vinyl Xetan. Hiu qu nht ca cht ph gia ny l ch cn

hm lng nh c trong du Diesel khong 5 8%.5. Ngoi ra cn c nhiu cht ph gia khc nh: Cht ph gia tyra, cht chng ng t.

2.2.2.3. Thnh phn cc tp cht

1. Hm lng ccTiu chun xc nh astm d 198, TCVN 6324 - 97Hm lng cc c nh gi bng cc, l lng cn du hnh

thnh trn b mt b sy nng do s phn hu nhin liu nhit

cao. S dng nhin liu c cc ho cao dn n hnh thnhcn du trn ming vi phun, trn rnh xc mng, trn thnh bungchy, trn thnh ng x.Ngoi ra cc ho ca nhin liu cao dnn hnh thnh keo trn thnh Piston, ng lt xilanh, rnh cc xcmng kh v th lm tng tn tht c gii nh kt xc mng, xcpiston Nc ta quy nh cc ho khng qu 0,3kl.2. Hm lng tro.

Tiu chun xc nh astm d 482, TCVN 3690 - 97Hm lng tro c nh gi bng tro, l nhng cht cn khng b

t chy ca nhin liu. Bao gm cc mui oxit kim loi, tp cht chc ri vo du trong qu trnh vn chuyn, bo qun. tro cnh gi bng kch thc ht cng to thnh sau khi t chy nhinliu, n c kh nng mi mn cc chi tit. Khi nhit khng ln hn5500C, tro to thnh khi nhin liu chy v c thi ra ngoi cng khthi.

tro c tnh theo % trong khi lng nhin liu. Vi nhin liu Diesel tro khng qu 0,01% (TCVN 2690 - 1995).3. Hm lng lu hunh

Tiu chun xc nh astm d 129, 2622

Lu hunh l mt cht c hi v hp cht ca n trong iu kin xcnh c kh nng n mn cc chi tit kim loi nh: Piston, xilanh, ngng x..

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Khoa c kh ng Lc - Trng HSPKT Hng YnHp cht lu hunh hnh thnh l do chy lu hunh l mt trong nhng

nguyn nhn ch yu n mn ng lt xilanh. Do lin kt Anhydritsufuric vi hi nc cha trong sn phm chy to thnh hi axt v axt n mn kim loi. Ngoi ra khi nhit thnh xilanh thp gy ngngt a xt lu hunh dn n n mn. Ngoi ra sn phn chy lu hunhv hp cht ca n, lm tng mi mn cc chi tit lm vic v chngc cng cao do du bi trn cn c bn thch hp. Yu cuhm lng lu hunh khng vt qu (0,5 1% kl).Qua nghin cu cho thy khi hm lng lu hunh tng t 0,12 0,57

th mc n mn piston tng 5,5 ln, xilanh tng 3,5 ln.4. Hm lng nc

Tiu chun xc nh astm d 95Nc ln vo nhin liu trong qu trnh vn chuyn, bo qun. Nhin

liu cha nc lm tng mc in ly ca cc cht gy n mn lntrong nhin liu do n gy n mn cc thit b cha, do dn

n ng c kh khi ng gy gin on s lm vic ca ngc. Theo mt s quy nh, hm lng nc khng qu 1%.5. Hm lng tp cht c hc

Tiu chun xc nh astm d 2709, 95, 96Tp cht c hoc trong nhin liu ch yu l cc ht cc c hc, kim

loi, r st ri vo nhin liu khi iu ch, bo qun, vn chuyn.Tpcht ny lm bn kt ng, mng lc, lm tng mi mn ca ccchi tit nh ng lt xilanh, xc mng, vi phun.

Theo tiu chun trong nhin liu Diesel khng cho php cha cc tpcht c hc.

2.2.3. c tnh v ch tiu cht lng du Diesel2.2.3.1. Tnh chy ca nhin liu Diesel

Trong xilanh ng c, khng kh c nn ti mt nhit v psut nht nh, lc ny nhin liu c phun di dng ti sng vobung t, gp khng kh nng, nhin liu nng dn ln t ti nhit t chy khi hi nhin liu t bng chy m khng cn tia laca bugi. Khi hi nhin liu Diesel t bng chy th ng c bt ulm vic. thc hin chu k lm vic bnh thng th nhit

khng kh cui k nn phi cao hn nhit bc chy ca nhin liu.V d nhin liu ng c t nhit bn chy cao hn 650C.

Hin tng chy ca nhin liu Diesel xy ra hai trng hp l hintng chy bnh thng v hin tng chy khng bnh thng .1. Hin tng chy bnh thng: Nu hi nhin liu c nhit

chy thch hp, d t bn chy, thi gian bn chy ngn, th khibt u chy hi nhin liu tch t trong bung chy nhiu, hin t-

ng chy xy ra bnh thng, p sut, nhit chy tng u n.2. Hin tng chy khng bnh thng: Nu hi nhin liu kh t

chy, thi gian chy tr ko di lm cho hi nhin liu tch lu kh

nhiu trong bung t. Do vy khi bt u t chy, hi nhin liu schy mt cch mnh lit lm p sut, nhit bung chy tng mnhlit lm p sut, nhit bung chy tng t ngt, gy sng chn

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Khoa c kh ng Lc - Trng HSPKT Hng Ynng p vo thnh xilanh to tig ng, hi nhin liu chy khngkp, x khi en l tt c biu hin ca qu trnh chy khngbnh thng ging hin tng kch n ca hi xng trong ng cxng.- nh gi tnh t chy ca nhin liu Diesel ngi ta dng tr sXetan (TSXT). Nhin liu c tr s Xetan cao th nhit t bc chycng thp, tnh t chy tt.TSXT ca nhin liu ng c Diesel c xc nh trong my o trs Xetan, da trn so snh s bn chy trng lp ca nhin liu thngin vi nhin liu chun.TSXT ca nhin liu Diesel c lin quan trc tip ti tc quay cang c, do vy mun ng c hot ng bnh thng, bo mcng sut th i hi nin liu phi c tr s Xetan ph hp tc quay ca ng c.

ng c t tc thng ln hn 100vng/pht nn tr s Xetan

phi trn 50. Khi ng c lm vic m, t cng sut cao m tr sXetan thp hn yu cu th ng c lm vic kh khn, my nng,cng sut gim. Khi tr s xetan ca nhin liu cao hn mc yu cu,th hi nhin liu t chy qu nhanh nn chy khng hon ton, xkhi en, bn my, tiu hao nhin liu v gy nhim mi trng.Thng thng tr s nhin liu c TSXT vo khong 40 50 s dngtt cho cc ng c hot ng vo ma h v TSXT khong 50 55 ttcho ng c lm vic vo ma ng.

2.2.3.2 Tnh bay hi ca nhin liu

Tnh bay hi ca nhin liu nh hng rt ln n s hnh thnhhn hp nhin liu trong khng kh khi qu trnh to hn hp chy thchin u n ng c s hot ng bnh thng v n nh, khiqu trnh chy to ra bt thng s lm cho hot ng ca ng ckhng n nh. nh gi bay hi ca nhin liu Diesel ngi taxc nh thnh phn im si.- Tiu chun xc nh thnh phn im si:Ch tiu cht lng ny c xc nh trong dng c trng ct tiu

chun ho. i vi du Diesel cn xc nh thnh phn im si nh

sau:- im si 10%- im si 50%- im si 90%

Thnh phn im si ca nhin liu Diesel c ngha thc t khi sdng.1. im si 10%. Biu th cho thnh phn nh trong du Diesel yu

cu thnh phn ny chim mt t l nht nh. Thc t yu cu T 10% 2000C. Nu T10%< 2000 chng t trong du Diesel c t l hp phnnh cao, khi chy s lm tng nhanh p sut dn ti chy kch n.Nu thnh phn nh qu nhiu dn n s phun sng khng tt,gim tnh ng nht ca hn hp dn n nhin liu khi chy to khi

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Khoa c kh ng Lc - Trng HSPKT Hng Ynen, mui than lm bn my v pha long du nhn, ng c lmvic km cng sut.2. im si 50%V. nh hng n tnh khi ng my. Nhin liu c

im si T50% thch hp (2800C) s khin ng c khi ng d dng.3. im si 90% Biu hin cho kh nng chy hon ton ca hi

nhin liu. T90% ca du Diesel khng ln vt qu nhit 3700C. Quathc t cho thy thnh phn im si ca nhin liu Diesel nh hngrt ln ti cng sut lm vic v tui th ca ng c.

- Khi 3000C ct c 93% th tch th nhin liu tiu hao l100%

- Khi 3000C ct c 80% th tch th nhin liu tiu hao l117%

- Khi 3000C ct c 20% th tch th nhin liu tiu hao l131%Thnh phn im si khng hp l gy mn xc mng, xilanh

- Khi ct c 50% 2300

C th khe h xc mng l 0,6mm- Khi ct c 50% 3000C th khe h xc mng l 0,8mm- Khi ct c 50% 3500C th khe h xc mng l 1,2mm

Thnh phn im si cn nh hng ti lng kh x.- Khi 3000C ct c 95% th tch th lng khi x ra l 43

n v khi- Khi 3000C ct c 75% th tch th lng khi x ra l 63

n v khi- Khi 3000C ct c 20% th tch th lng khi x ra l 85

n v khi

2.2.3.3 nht ca nhin liu

Mt trong nhng ch tiu quan trng nht ca nhin liu Diesel ls lu chuyn d dng trong h thng cung cp nhin liu v np nhinliu vo bung t ca ng c. Tnh cht ny cn c bit quantrong khi ng c hot ng ni c nhit mi trng thp nh ccx lnh cht lng ny c nh ga bng ch tiu nht v nhit ng c.

1. nht ng hc

Tiu chun xc nh astm d 445, TCVN 3171 - 95C nhiu loi nht nhng thng thng s dng nht ng hc

nh gi tnh lu chuyn ca nhin liu Diesel. C s ca phngphp xc nh nht ng hc l o thi gian lu chuyn ca mt l-

ng th lng qua mao qun ca ng o nht.Nhng yu t nh hng n nht ng hc ca nhin liu Diesel.a). nh hng ca cu trc phn t th lng

Thc t cho thy phn t cng cng knh, nhiu nhnh, nhiu mchth nht cng cao.b). nh hng ca nhit .

Nhit tng v nht ca ca du gim v ngc li, c bt nht thay i nhanh trong phm vi nhit di 00C.

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Khoa c kh ng Lc - Trng HSPKT Hng YnYu cu nhin liu Diesel c nht ng hc ph hp nu nht

nhin liu Diesel cao, tnh lu chuyn b hn ch, nhin liu kh vnchuyn v np cho bung t. Nht l khi ng c lm vic trongmi trng nhit thp. Nu nht qu thp s lm gim h s npnhin liu do xc nh tnh ph hp ca nht di vi tngloi ng c v tng vng kh hu khc nhau th nht ca duDiesel 2000C t 1,5 6 l ph hp. nc ta s dng nhin liu dng cho ma h c nht t 3 6 200C.

2. Nhit ng c nc ta dung nhit ng c khng qu 5 -90C, cn cc nc

x lnh th dng loi nhin liu phn bit theo ma do vy nhit ng c c th l:-450C.

2.2.3.4. Tnh n mn ca nhin liu Diesel

Cng nh trong nhin liu xng trong nhin liu Diesel c mt lng tpcht mang tnh n mn nht nh.

Yu cu lng tp cht ny khng dc vt qu gii hn cho php tnh n mn khng nh hng ti cht lng nhin liu. Tnh n mn kimloi ca nhin liu Diesel c nh gi bng ch tiu cht lng: Kimnghim n mn mnh ng, hm lng lu hunh tng s v axitca nhin liu.1. Kim nghim tnh n mn mnh ngTiu chun xc nh astm d 130, TCVN 2694 - 95

Cc nhin liu Diesel cn c kim nghim tnh n mn mnhng nhit xc nh trong khong thi gian quy nh. Bngcch ngm mnh ng vo du trong thi gian ba gi nhit 500C sau so snh vi mu sc ca mnh ng vi mu sc quynh v rt ra kt lun.2. Hm lng lu hunh

Hm lng lu hunh khng dc vt qu quy nh nh d trnh by.3. axitTiu chun xc nh astm d 974, 664, TCVN 2695 axit trong du c xc nh bng lng KOH trung ho vi

lng axit trong du, n v o (mgKOH/g).

2.2.3.5 Tnh mi mn ca nhin liu Diesel

Khi vn hnh bt c loi ng c t trong no u c cc cnccbon to thnh cc dng khc nhau. Hin tng ny c bit thyr trong ng c Diesel. Do nhin liu Diesel tng i nng v iukin lm vic ca ng c kh khc nhit. Cn ccbon to thnh lnguyn nhn c bn tng tnh mi mn ca ng c. Ngoi ra

Trong nhin liu Diesel c th ln cc loi ct, bi, mt kim loi.

C tn chung l tp cht c hc(nh trnh by) cc tp cht nycng vi cn ccbon tng tnh mi mn i vi cc chi tit my. Tnh

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Khoa c kh ng Lc - Trng HSPKT Hng Ynn mn ca kim loi c nh gi bng ch tiu cht lng hm lng tro, cc, hm lng tp cht(nh c trnh by).

2.2.3.6 Tnh nng an ton chng chy n

c trng cho tnh an ton chng chy n ca u Diesel, ngita quy nh nhit bn chy ca du. Nhit bn chy l ti hi nhin liu c t nng to thnh hn hp vi khng kh v b bnchy khi c mi la gn.Nhit bn chy ca u Diesel theo quy nh khng thp hn

50 650C.

2.2.4 Phn loi du Diesel2.2.4.1. Phn loi theo s vng quay ca ng c v tr s

xetan- Nhm 1: Nhin liu dng cho ng c cao tc phn lm hai loi

nhin liu.- Loi Super c tr s xetan bng 50 v phm vi si l 180

3200C c dng cho ng c tc cao nh ng c t.- Loi thng tr s xetan bng 52 nhng si rng hn 175

3450C nhng c sn xut bng cch pha trn t l hp l cc sn phmkhc nhau ca qu trnh chng ct du. Nhin liu ny dng cho ngc cao tc nhng cht lng km hn loi Super.

- Nhm 2: Nhin liu dng cho loi ng c thp tc cng i hicht lng tiu chun nhin liu nh nhin liu dng cho ng c cao tctuy nhin tr s xetan nh hn, lm trong khong 40 45, bay hithp, im si cui cao hn khong (360 3700C).

2.2.4.2 . Phn loi nhin liu theo hm lng lu hunh

- Nhin liu Diesel c hm lng lu hunh khng ln hn 0,5% khi lngk hiu DO 0,5%S.- Nhin liu Diesel c hm lng lu hunh t 0,5 1% khi lng, k hiu

DO 1%S.

2.2.5. Yu cu k thut ca nhin liu DieselTheo tiu chun ca Vit Nam Du Diesel c nhng c tnh sau:

Bng 2.2.1 Ch tiu cht lng nhin liu Diesel

Tn ch tiu Mc Phng phpthDO

0.5%SDO

1,0%S1. Tr s Xetan khng nh hn 50 45 ASTM D 9762. Hm lng lu hunh(%kl) 0,5 1,0 ASTM D 129

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khng ln hn ASTM D 2622

3. Nhit ct (0C) 90% thtch khng ln hn

370 370 TCVN 2698 95

4. im bn chy cc kn (0C),

khng nh hn

60 50 TCVN 2693 95

ASTM D 935. nht ng hc 400C(cSt,mm2/100ml)

1,8-5,0

1,8-5,0 ASTM D 445

6. Cn cc bon ca 10% chngct (%kl), khng ln hn

0,3 0,3 TCVN 6324 97ASTM D 189

7. im ng c (0C), khngln hn

- Cc tnh pha bc

- Cc tnh pha nam(T Nng tr vo)

+5+9

+5+9

TCVN 3753 95ASTM D 97

8. Hm lng tro(%kl), khng lnhn

0,01 0,01 TCVN 2690 95ASTM D 482

9. Hm lng nc tp cht chc (%kl), khng ln hn

0,05 0,05 ASTM D 2709

10. n mn mnh ng 500Ctrong 3h, khng ln hn

N01 N01 ASTM D 130TCVN 2694 - 95


2.2.6. c tnh, chng loi du Diesel trn th trng.2.2.6.1. Trn th trng th gii

Bng 2.2.2 Cht lng nhin liu Diesel ca cc nc SNG

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Bng 2.2.3 Cht lng nhin liu Diesel Trung Quc

n tt nghip

Tn ch tiu Tiu chun Mc quy nhMang

Ma h

1. T trng 150C GOST 3900 Max0.84 0,8602. Tr s Xetan GOST 3122 Min 45,0 45,03. Hm lng lu hunh(%kl)

- Loi 1- Loi 2

GOST 19121Max0,2Max0,5

0,20,5

4. Hm lng nc (%V) GOST 5985 Khng Khng5. axit (mgKOH/100ml) GOST 2477 Max5,0 5,06. Nhit bn chy cc kn(0C)

- Diesel thng mi- Diesel thng dng

GOST 6356Min40,0Min35,0

62,040,0

7. nht ng hc 200C GOST 33 1,8 5,0 3,0

6,08. Hm lng tro (%kl) GOST 1461 Max0,01 0,019. Nhit ng c (0C) GOST 5066 Max-

35,0-10,0

10. Thnh phn im si(0C)- 50% th tch- 90% th tch

GOST 2177Max 280Max 340

280,0360,0


Kt quc trng

1. T trng 600F ASTM D1298

Max0,8494

-

2. Hm lng luhunh(%kl)

G. B 380 Max0,30 0,031

3. n mn mnhng3h/500C

ASTM D 130 Max1 1

4. Cn cacbon (%kl) ASTM D 189 Max0,15 -5. Nhit bn chycc kn (0C)

ASTM D 93 Min66,00 86,0

6. nht ng hc 200C

ASTM D 445 Max8,00 4,69

7. axit (mgKOH/100ml) ASTM D 974 - 0,048.Hm lng tro (%kl) ASTM D 482 Max0,01 -9. Tr s Xetan ASTM D 976 Min48,00 66,0010.Hm lng nc (%V) ASTM D 95 Max0,05 c vt11.Nhit ng c(0C)

ASTM D 97 Max0,00 -

12.Mu sc ASTM D1500

Max1 1

13. Thnh phn imsi(0C)- 50% th tch- 90% th tch

ASTM D 86 Max280,00Max330,00

274319

44


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Bang 2.2.4 Cht lng nhin liu Diesel ca Nht bn

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1. T trng 600F ASTM D 1298 0,830 0,8502. Hm lng lu hunh(%kl) ASTM D 1151 Max0,303. n mn mnhng3h/1000C

ASTM D 130 Max1

4. Cn cacbon (%kl) ASTM D 189 Max0,15. Nhit bn chy cckn (0C)

ASTM D 93 Min60,00

6. nht ng hc 200C ASTM D 445 2,70 5,007. Cn y (%kl) ASTM D 437 Max 0,018. Hm lng tro (%kl) ASTM D 482 Max0,019. Tr s Xetan ASTM D 976 Min50,0010.Hm lng nc (%V) ASTM D 95 Max0,0511.Nhit ng c (0C) ASTM D 97 Max-12,0012.Mu sc ASTM D 1500 Max0,513. Thnh phn im si(0C)

- 50% th tch

- 90% th tch

ASTM D 86Max350,00

Max312,00

45


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Khoa c kh ng Lc - Trng HSPKT Hng Yn2.2.6.2 Trn th trng Vit Nam(Cng ty PP)

Bng 2.2.5

S THT

TN CH TIU MC PHNG PHP TH

DO 0,05%S DO 0,25%S DO 0,50%S

1 Ch s xetan, khngnh hn

45 45 45ASTM D976

2 Hm lng luhunh, %khi lng,khng ln hn

0,05 0,25 0,5TCVN 2708:2002/(ASTMD 1266)/ TCVN6701:2002(ASTM D 2622)/ASTM D129/ ASTM D4294

3 Nhit ct, oC,

90% th tch, khngln hn

370 370 370

TCVN 2698:2002/ (ASTMD 86)

4 im chp chy cckn, oC, khng nhhn

50 50 50

TCVN 6608:2000/ (ASTMD 3828)/ ASTM D 93

5 nht ng hc 40oC, cSt(mm2/ s)

1,6 - 5,5 1,6 - 5,5 1,6 - 5,5

ASTM D 445

6 Cn cc bon ca10% cn chng ct,%khi lng, khngln hn

0,3 0,3 0,3

TCVN 6324:1997/ (ASTMD 189)/ ASTM D 4530

7 im ng c, oC,khng ln hn

9 9 9TCVN 3753:1995/ ASTMD 97

8 Hm lng tro,%khi lng, khng

ln hn

0,01 0,01 0,01

TCVN 2690:1995/ ASTM

D 482

9 Hm lng nc vtp cht c hc,%th tch, khng lnhn

0,05 0,05 0,05

ASTM D 2709

10 n mn mnh ng 50oC, 3 gi, khngln hn

1 1 1

TCVN 2694: 2000/ (ASTMD 130-88)

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S THT

TN CH TIU MC PHNG PHP TH

DO 0,05%S DO 0,25%S DO 0,50%S

11 Khi lng ring 15oC, kg/l

Bo co Bo co Bo coTCVN 6594: 2000/ (ASTMD 1298)

Chng III. Du, m bi trn

3.1. Du bi trn3.1.1. Cng dng chnh ca du bi trn

Trong qu trnh hot ng ca cc c cu chuyn ng, du bitrn c cc cng dng sau: 3.1.1.1. Tc dng bi trn

Du bi trn c nhiu tc dng nhng tc dng quan trng nht ltc dng bi trn cc b mt ma st nh : C trc khuu, c trc bin,piston - xilanh, bc v cht piston, bnh rng c cu truyn lcchnh, hp s.Nguyn nhn gim c ma st l do khi bi trn s cs thay th trc tip ma st gia cc chi tit bng ma st ni ti cadu bi trn ngn cch cc chi tit. V D: chuyn ng gia bcv trc. Trc quay trong bc c bitrn bng mt lp du mng, cgi li bi tc ng nm. (Hnh V).Cc phn t du dnh vo b

mt quay theo trc, do lc c ktgia cc phn t ny keo theonhng lp lin k.Tuy nhin trc c xu hng b ko

vo lp du, do trng lng bn thn, do lc ti kt qu l trc b lchtm so vi bc, do trc quay lc c kt gia cc phn t du mt slp phn t du b ko vo hoc b nm di trc, tc ng nm nynng trc ln v to ln lp du mng gia bc v trc.

hiu r hn tc dng bi trn ca du ta xt v d sau:V d v h s ma st gia cc trc thp.

- Ma st trc tip, khng c du 0,8 1,0- C du nhn ch bi trn thu ng: 0,001 0,01- C du nhn ch bi trn thu tnh: 0,0001 0,001

2. Tc dng chng n mnNc l mt nguyn nhn gy ra s g st ca cc chi tit c ch

to t kim loi. Mt th tch nhin liu b t chy trong ng c,sn sinh ra mt lng nc nht nh mc d phn ln lng nc ny thhi v thot ra qua ng x tuy nhin vn cn mt lng nh bn vothnh xylanh v lt qua xc mng v ngng li trong y cc te. Hin t-

ng ny thng xy ra khi thi tit lnh hay khi ng c cha c si mthm vo l do cc sn phm ph sinh ra do nhin liu chy d,nhng kh chy c tnh n mn lt qua xc mng ri ngng li hoc

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Khoa c kh ng Lc - Trng HSPKT Hng Ynho tan trong du ng c v vy kh nng to g st v n mncng tr ln trm trng.Do vy cc chi tit cn c bo v chng n mn v chng g.

Mng du bi trn ph ln b mt cc chi tit ma st c tc dngchng g cho my mc trong thi gian ngng hot ng nht lnhng b phn m t nh tuc bin hi .Ngoi ra chng c tc dnghn ch ti a s lan truyn cc cht axit mt sn phm ca qutrnh chy cc loi hp cht lu hunh trong ng c Diesel. Tui thca ng c ph thuc mt phn vo kh nng trung ho ca dumy, i vi nhng hp cht c tc dng n mn. du nhn mbo chc nng ny phi dng loi ph gia mang tnh kim c tc dngtrung ho cc axit to ra khi nhin liu chy Trong qu trnh s dngdu nhn hm lng ph gia ny gim dn. Khi t l ph gia thp diquy nh cho php th du khng cn phm cht na.3. Tc dng lm mt

Do ma st ti cc b mt lm vic nh: Piston xilanh, truc khuu bc lt, cp bnh rng hp s, cu.u pht sinh ra nhit rt ln,cng thm nhit do kh chy to ra. Do vy h thng lm mt lrt cn thit, tuy nhin dung dch lm mt khng khng th nhnnhit t cc chi tit nh: Piston, cc cp bnh rng.Nn nhng chi titny c lm mt bng du, du t y cc te c nhit thp cdn ti b mt c nhit cao, du trong cu, trong hp s c bmtheo bnh rng v nhn nhit sau tn nhit ra mi trng khngkh theo v cc te, cu, hp s.

c bit du l phng tin chnh lm mt piston v cc cp bnh

rng n khp. Thc t cho thy khi dng du lm mt dn n phnnh di ca piston gp s c th piston b kt ngay. Qua nhng sthc nghim cho thy nhit chy thng l:1090 16500C. Nhng phn chnh ca van c th ln ti 540 1095 0C.Nhit piston c th ln ti 5400C v nhit ny truyn xungthnh truyn v bc. Thic v ch l hai kim loi c nhit nngchy thp c dng ch to cc chi tit ca bc chng thngmm ra 1800C v nng chy 2320C v 2370C tng ng vi mi kimloi khi du trong cc te thng c nhit trong khong 90 1200C v chng c a ti v hp th nhit ti y duy tr mt

nhit an ton cho bc v vng bi. m bo chc nng ny, yu cu du phi chu nhit cao,

khng b bin cht do tc dng ca xy trong khng kh ti nhit cao v mc du phi cao hn mc ti thiu cho php.4. Tc dng lm kn Mng du bi trn ngn cch cc chi tit chuyn ng trong ngc, ngoi tc dng bi trn gim ma st, du cn c tc dng lm kn.

Trn thc t b mt ca xc mng, rnh xc mng, thnh xilanhkhng trn chu v hon ton tip xc kn vi nhau hn na sau mtthi gian hot ng, xc mng gim n tnh , mn, xilanh mn

khng u dn n khe h gia chng ngy cng rng v gy ltkh trong k nn v chy dn n. Du c tc dng bao kn khe h ,ngn cn ti a khng cho cc loi kh nng trong qu trnh chy i

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Khoa c kh ng Lc - Trng HSPKT Hng Ynqua xc mng. kn ca piston, xilanh ph thuc vo nht cadu bi trn. V vy khi lp rp cm chi tit ny phi bi du vornh xc mng v b mt xilanh.5. Tc dng lm sch

Trn cc b mt ma st, trong qu trnh lm vic thng c vy rntrc ra khi b mt. Du nhn s cun tri cc vy trc ny sau gi li trong bu lc ca h thng bi trn trnh cho b mt mast b co xc. V vy khi ng c chy r sau khi lp rp hoc sacha. Ngoi ra trn ng c Diesel, kh nhin liu chy to ra muithan cn trnh mui than bm trn thnh xi lanh, piston.

3.1.2. Thnh phn ca du nhn

Du nhn thng phm bao gm ba thnh phn chnh:- Thnh phn gc du m

- Thnh phn cc cht ph gia c trong du- Thnh phn tp cht c trong du

3.1.2.1 Du ang lu hnh trn th trng gm hai chng loi:

- Du ch bin t du m- Du tng hp

1. Du ch bin t du m

a). Thnh phn Hydroacbon ca du gc thnh phn ch yu ca

du bi trn l cc hp phn Hydrocacbon bao gn cc nhm:- Nhm Hydrocacbon Naphten pafin. y l nhm Hydrocacbonch yu c trong du bi trn hm lng ca chng c th ln ti 40 80% tu thuc loi du m, nhm ny c cu trc ch yu lHydrocacbon vng naphten c kt hp vi nhm ankyl hoc iso ankyl.S nguyn t Cacbon trong phn t c th t 20 70 nguyn t, loiHydrocacbon ny c tnh bi trn tt, tnh n nh ho hc tt do chng l thnh phn tt ca du bi trn ngoi ra c ccHydrocacbon dng n parafin v iso parafin vi hm lng khng ln,mch cacbon khng qu 20 nguyn t. Loi Hydrocacbon ny c tnh

n nh ho hc tt, tnh bi trn t thay i theo nhit nhng nht thp nhit khng cao.

- Nhm Hydrocacbon thm v Naphten thm. Nhm ny bao gmcc hp cht trong dy ng ng ca Benzen, naphtalen, i khi cnc ng ng ca traxen, mt hp phn na l cc Hydrocacbon hntp bao gm trong phn t c vng thm v naphten. NhmHydrocacbon ny d b xy ho to ra cc hp cht keo nha ngthi c tnh bi trn thay i nhiu theo nhit do vy chng lhp phn lm gim cht lng du thng phm.

- Nhm Hydrocacbon rn c trong nguyn liu sn xut du bi

trn, i khi ln ti 40 - 50% tu thuc bn cht du th, phn lnnhng hp cht ny c loi khi du trong qu trnh thc lc parafin.

Tu vo cch tch lc m Hydrocacbon rn ny c c tch trit

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Khoa c kh ng Lc - Trng HSPKT Hng Ynhay khng , d sao chng vn tn ti trong du vi hm lng nh, s cmt ca nhm Hydrocacbon ny lm tng nhit ng c, lmgim kh nng s dng du nhit d thp, nhng li tng tnh nnh ca nht theo nhit v tnh n nh chng xy ho.Nhm ny c hai loi: Nhm Hydrocacbon rn l parafin rn (c thnhphn ch yu l cc alkan c mch cc bon ln hn 20) v Xrezin (lhn hp cc Naphten c mch nhnh alkyn dng thng hoc dngnhnh v mt lng khng ng k Hydrocacbon rn c vng thm vvng nhnh Alkyn).

b). Du nhn tng hp. Du nhn ni chung, du ng c ni ringc ch bin ch yu t du khong gc m. Ngoi ra c loi dunhn c ngun gc l sn phm ca cc phn ng ho hc gi l dutng hp.

Du tng hp ra i do s i hi pht trin ca cng ngh chto ng c v cc loi thit b. Ch lm vic ca cc b mt ma

st, cc chi tit my ngy cng khc nghit, phc tp hn trong trnghp du nhn gc khong biu hin nhng nhc im kh khcphc nh tnh n nh ho hc, tnh n nh nhit khng cao khnng lm vic nhng nhit thp khng tt, khng p ng ihi bi trn tt phm vi nhit rng .

Nh tnh u vit ca du tng hp l c th lm vic trong phm virng hn, tr v mt ho hc. t tiu hao nhin liu, khng gy chiDu tng hp ngy cng c nhiu ng dng khc nhau nh lmdu ng c, du phanh, du hp s.

Du tng hp c 4 nhm Cc hydrocacbon tng hp cc este hu

c, cc estephospht v cc polyglycol.- Nhm Hydroccbon tng hp. Cc Hydrocacbon tng hp thch hplm cht bi trn c sn xut nh qu trnh Polymeho cc olefin,Alkyn ho cc olefinTrn thc t thng dng nhng cht nh Poly iso buten, cc Polyalkyn benzen.bn cht ho hc ca chng l ccHydrocacbon kh tinh khit.

Cc loi Hydrocacbon tng hp l cc loi du pht trin nhanhnht, chng thng c sn xut ly nguyn liu t du th . Khc vidu bi trn gc du m, cc Hydrocacbon c gii hn si hp, nhit ng c thp (do khng c cc phn mch di), nht t thay

i theo nhit . Ngoi ra kh nng tip nhn ph gia ca chngkh tt, mt trong nhng loi du ph bin thuc nhm ny l duPolyalphaolefin(PAOS), dng bi trn trong ng c t v trong cngnghip, c s dng ph bin cc nc pht trin, nhit ngc thp di 400C ch s nht hn 140 v bn nhit cao.

- Cc nhm este hu c. Nhm ny dng lm du tng hp bao gncc este diaxit v este polyol c cng thc ho hc nh sau:

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O O

R O C (CH2) C O R

CH2- OH

HO - CH2 C CH2- OHCH

2-

OH


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Khoa c kh ng Lc - Trng HSPKT Hng Yn- Cc Este diaxit c iu ch t phn ng ca diaxit vi ru cha

mt nhm Hydroxyl. Du tng hp loi ny nhit ng c rtthp -50 - -600C, bn nhit cao v kh nng ty ra tt chng clm ch yu t du gc hay mt thnh phn ca du gc.

- Cc este polyol c iu ch t polyglycol v monoaxit no, ccaxit in hnh c dng c t 5 10 nguyn t cc bon c ly tngun du ng thc vt. Du tng hp gc este polyol c nhit ng c -30 ti -700C, ch s nht 120 170, bn nhit khcao, hin nay chng c dng pha ch cc loi du bi trn dngcho my bay, ng c t, tuc bin tu thu.

c). Nhm este phosphat: c trng chung ca nhm ny l tnh chunhit cao hn nhiu so vi du khong v tnh bi trn cng tt. Mtlng ng k sn phm ny c dng lm cht bi trn cho my nn nhng ni nhit cao trch c s bn la thng xy ra i vi loidu thng thng. Este phosphat cng c lm cht ph gia chng mi

mn , du ny c nhit ng c khong t -5 ti -200

C, estephosphat c cu trc:

d). Nhm polyAlkyn glyconl nhng hp cht polyme c tng hptrn c s cc monome m cht n gin nht trong nhm lEtylenglycol c cng thc:

HO - CH2 - CH2 OH

Ngoi ra cn c cc polyme ca etylen hoc pro pylen xit hocc hai c dng nh sau:HO (CH2 - CH2)n

3.1.2.2 Ph gia du nhn

Ph gia du nhn l nhng hp cht h c, v c, thm tr cc ccnguyn t ho hc c pha v du vi nng thng thng t 0,01 5%kl. Trong mt s trng hp c th t vi phn triu ln ti 10%,.Nhm ci thin hoc gia tng c tnh ca du nhn nh tnh chng

xy ho, chng g, ty ra. du s dng 70c hiu qu hn.Nhng cht ph gia dng trong du bi trn bao gm:1. Ph gia chng xy hoKhi ng c, my mc lm vic, du chu tc ng ca xy trong

khng kh, to ra cc sn phm xy ho, nhng sn phm ny dndn ngng t li to thnh cc cht kh tan, gy cn tr cho qu trnhhot ng bnh thng ca ng c, my mc. hn ch qu trnhny cn cho thm vo du loi ph gia c ch xy ho.

i vi loi du bi trn trn t ph gia c ch xy ho thng cnhit cao. l cc mui ca axit hu c nh km

Dialkylithiophosphat, mui ca alkyl sailixilat.2. Nhng cht ph gia bo v b mt kim loi

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O(Ar)R O P O R(Ar)

O R(Ar)R Nhm AlkynAr Nhm thm


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Khoa c kh ng Lc - Trng HSPKT Hng YnNhng cht ph gia ny c tc dng chng li nh hng ca axit n

mn v hi m. Chng va chung ho cc cht axit, va to ra trn bmt kim loi mt lp mng bo v, lp mng ny c tnh k nc. C tcdng chng m, chng cho nc thm qua. Tu tng loi du m ngi tadng cht chng g khc nhau, nh vi du tuc bin thu lc.th dngcc axit nh: Alkyn thioaxetic, v nhng dn sut ca chng.i vidu bi trn ng c dng Sulfomat, aminphosphat, este, ete.i vidu bnh rng dng imidazonin.3. Ph gia c tnh ty ra v khuych tn

Nhng ph gia ny c tc dng hn ch s nng ng ca snphm xy ho gi cho b mt c sch s, ph gia ty ra thng lcht hot ng b mt, d hp th trn b mt kim loi khinnhng cht cn bn khng tch t li c. Ph gia khuych tn, ngncn cc sn phm xy ho, cc cn c hc kt dnh li vi nhau, khincc phn t ny tn ti di dng trng thi keo, l lng trong du,

nhng ph gia ny thng l nhng mui kim loi vi cc cht hu cc mch cc bon di v c cc nhm phn cc nh: (- OH), -C6H4OH, - COOH, - NH2, - SO3H. C th l cc mui Sufomat, phenolat,Solixilat,4. Cht ph gia ci thin nht v ch s nht

Cht ph gia loi ny tan c trong du, chng l cc polyme tcdng tng nht. c bit tng rt t nht ca du nhit thp nhng nhit cao chng tng nht ca du mt cch ngk, ngha l chng lm cho nht ca du t bin i theo nhit do lm tng ch s nht ca du. Nguyn nhn ca c

tnh trn l do khi nhit thp cc phn t polyme xon li chnglm nht ca du tng t, ngc li khi nhit cao cc phn tpolyme dui di v lm tng ng k nht ca du. Cc ph giany c chia lm hai nhm: c chia lm hai nhm nhm Hydrocacbonv nhm este c nhng ph gia nh: Copolymeetelen propy, poly iso buten.Nhm este c nhng ph gia nh polymetacrylat.5. Cht ph gia h nhit ng c Loi cht ph gia ny c tc dng h thp nhit ng c cadu bi trn lm chm qu trnh to thnh cc tinh th c kch thc

ln ca Parafin rn nh chng bao bc xung quanh hoc cng kt tinhvi Parafin. Do ch to ra tinh th nh thay v tinh th ln ccnhm vn xp hnh thnh khi khng c cht ph gia h im ng.S bin i hnh dng nh vy lm gim kh nng cc tinh th chngcho, an ci vo nhau, cn ch dng chy ca du nh th du vnlu chuyn tt khng b ng cng li.

Phn ln nhng ph gia h nhit ng c c cha cc snphm Polyme ho v ngng t trong s chng c mt s ph gia ngthi ci thin nht v ch s d nht, nhng ph gia ch yu trongnhm ny gm cac polyme Akylmetacrylat, cc polyme Alphaolefin, cc

naphtalen c alkyn ho, cc alkyn phenolmch di6. Cht ph gia chng to bt

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Khoa c kh ng Lc - Trng HSPKT Hng YnKhi to bt lm du tht thot nhiu, ngn cn s lu thng ca du,

gy ln bi trn khng y , lm tng thi gian phn hi ca hthu lc. Kh nng hn ch s to bt ca du khc nhau r rt, phthuc vo bn cht du th, phng php ch bin v nht cadu. hn ch s to bt c th dng cht ph gia chng to bt nh:Silicon lng c bit l Polymety siloxan l cht chng to bt chiu qu nht vi nng pha ch 1 20ppm. Thng thng nng pha ch ca cht chng to bt du ng c l 3 5 ppm, ca dutruyn ng l 15 20 ppm. Ngoi ra cn c nhiu cht ph gia khc.7. Cht ph gia kh nh

Khi du bi trn b nhim nc trong trng hp thch hp c th tothnh nh tng kh bn vng gi l nh nc trong du, th nh ny,th nh ny gy kh khn cho ch bi trn bnh thng. ngnchn hin tng ny ngi ta dng cht ph gia ph nh tng nh cht

Trialkyl phosphat, polyetylenglycol..

3.1.2.3 Tp cht du nhn1. Nc trong du

Hm lng nc trong du c tnh bng phn trm hay phntriu(ppm) so vi khi lng ca du. Nc trong du thng phm chyu ln trong qu trnh sn xut. Nu hm lng nc ln n 0,2% ccoi l c vt nc trong du.2. Hm lng tro trong du Hm lng tro c th c nh ngha bng lng cn khng chy hayl cc khong cht cn li sau khi chy du. Hm lng tro ny c xc

nh bng phng php t chy hon ton mt lng nhin liu, cckim loi to thnh cc oxit v c xc nh theo phn trm khi lngca du bng phng php phn tch khi lng. Trong du thngphm thng thng hm lng tro rt nh. Xc nh tro ca dunhm mc nh nh gi sch ca du v kim nghim xen chtph gia c y hay khng.3. Cn khng tan trong duTp cht khng tan trong du ch yu l bi lt vo trong qu trnh

ch bin, sn xut, do du b xy ho to thnh.

3.1.3 c tnh, ch tiu cht lng du bi trn3.1.3.1. Mt s tnh cht vt l ca du nhn

1. Khi lng ring v t trngi vi du bi trn khi lng ring t c ngha nh gi cht

lng. Khi lng ring ca du qua s dng khng khc nhau l myi vi khi lng ring ca du cha s dng. Tuy nhin mt gi tr btthng no ca khi lng ring cng c th gip phn on trongdu c phn nhin liu, dung mi hay cht kh no .

2. Mu sc dui vi ngi tiu dng mu sc ca du l mt ch tiu cm quan

mang tnh tm l. Thng thng cc loi du thng phm c mu nuvng vi nh xanh l cy hoc xanh l.

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3.1.3.2. Tnh bi trn v lu chuyn ca du

1. nht ca dui vi tng loi du nhn khc nhau th chng c nht khc

nhau ( nht c gi trn thng hiu ca sn phm). Trong khi s dngnu du khng thch hp s gy ra nhng tc hi sau:

- Khi nht qu ln s lm gim cng sut my do tiu hao cng thng lc cn ca du, kh khi ng my (nht l vo ma ng,nhit mt trng thp), gim kh nng lm mt my, lm sch mydo du lu thng km.

- Khi nht qu nh du khng to c lp mng bn vng bo vb mt cc chi tit my mc ln lm tng s ma st gy h hi b mtma st. Do vy du phi c nht ph hp vi tng loi ng c.(ctrnh by trong bng ch tiu)

2. Ch s nhtCh s nht l mt tr s chuyn dng, nh gi s thay i nht ca du bi trn theo nhit . Tr s nht cng cao cngha l nht ca du t thay i theo nhit .3. Nhit ng c v vn cYu cu du nhn c nhit ng c v vn c khng vt qu

gii hn cho php, nc ta yu cu nhit ng c ca du khngvt qu -90C.

3.1.3.3. Tnh bay hi ca du

Thnh phn chnh yu ca du nhn l cc Hydrocacbon c nhit si cao, do chng rt kh bay hi. Tuy vy ngi ta vn phinh gia tnh bay hi ca du nhn v c th c nhng thnh phnnh trong du, nht l i vi du qua s dng thng hay bnhim nhin liu. Tnh bay hi ca du c lin quan n tnh anton chy n nn c nh gi cn thn qua cc ch tiu bnchy, lng nhin liu ln trong du.1.Nhit bn chy ca du(Flash point)Tiu chun xc nh TCVN 2699 95 ASTM D 92

TCVN 2693 95 ASTM D 93c trng cho tnh nng an ton chy n ca du nhn l nhit

bn chy v bt chy.Nhit bn chy l nhit thp nht m ti hi du c th

thot ra v bn chy khi c mi la li gn.Nhit bt chy l nhit thp nht m ti lng hi thot ra

trn b mt du c th bn chy khi c mi la li gn v chy tnht 5 giy khng tt.

xc nh nhit chp chy ca du nhn c cc tiu chunASTM D 92 (phng php cc h Cleveland) tng ng TCVN 2699

95 v tiu chun ASTM D 93 (phng php cc kn Pensky Martens) t-ng ng TCVN 2693 95.

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Khoa c kh ng Lc - Trng HSPKT Hng YnNhit bn chy b bt chy ca mt s loi du bi trn thng

khc nhau t50- 60C, tu thuc d nht ca du, nht cng cao th cch bitcng ln. Theo ti liu vin du m php nhit bn chy v btchy ca mt s loi du nh sau:

nh gi nhit bn chy v bt chy ca mt loi du l xcnh s c mt ca nhng thnh phn si thp hoc nhien liutrong du. Theo quy nh cc loi du c nhit bn chy khng

qu quy nh nhm m bo an ton chng chy n trong qu trnhbo qun v s dng du, nht l ni nhit cao v khngthong. i vi du ng c tr s an ton ti thiu ca im btchy trong khi s dng c cc hng khuyn dng l t 150 1700C.2. Hm lng nhin liu ln trong du

Tiu chun xc nh ASTM D 322, ASTM D 3524, ASTM D 3525Vic ln nhin liu vo du ng c hay xy ra nht vo lc my

ang vn hnh. S pha tp qu mc ca nhin liu vo du lun gnvi s c ca my.

Tiu chun ASTM D 322 c dng xc nh hm lng xng (theo

%kl) ln trong du bi trn bng phng php chng ct.Tiu chun ASTM D 3525 xc nh hm lng xng v ASTM D3524 xc nh hm lng nhin liu Diesel(%kl) ln vo du bngphng php sc k kh vi nhng iu kin thch hp.

3.1.3.4. Tnh bo v kim loi ca du

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Nhit bnchy (0C) Nhit btchy (0C)95 100

150 165200 230260 300315 363340 400

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Khoa c kh ng Lc - Trng HSPKT Hng Yn1. Tr s axit, kim xc nh lng axit c trong du da vo tr s axit.a). Tr s axit tng (Total Acid Number - TAN) l ch tiu nh gi

tnh axit ca du, c trng bi s mgKOH cn thit trung hoton b lng axit c trong 1g du. Quy nh tuyt i khng c caxit trong du.

b). Axit trong nc. (Acid\Water) biu hin s c mt ca axit v c,c pht hin nh tnh theo s thay i mu ca cht ch th mui vi lp nc tch khi du nhn khi kim nghim. Quy nh tuyti khng c c axit v c trong du.

c). Tr s kim tng (Total Base Number - TBN). Tnh kim trongdu to ra bi cc ph gia c tnh ty ra, ph gia phn tn Tnhkim l ch tiu rt cn thit xt on ch tiu cht lng dunhn. Nhm bo m trung ho cc hp cht axit to ra trong qutrnh s dng.

nh gi TAN v TBN c nhiu tiu chun xc nh:- ASTM D 974 o TAN v TBN bng phng php chun vi cht chth mu thch hp, cn gi l t s trung ho.

- ASTM D 3339 o TAN bng phng php chun bn vi lng vicht ch th mu thch hp.

- ASTM D 664 o TAN v TBN bng phng php chun o inth, tng ngTCVN 6325 97.- ASTM D 2896 o TBN bng phng php chun o in k vi

axit pecloric, tng ng TCVN 3167 95.

2. Kim nghim n mn mnh ng.Theo phng php ny mnh ng c nh bng v ngm trongdu, ngi ta ra nhit ti nhit nht nh v gi trong thi gianquy nh, nhit v thi gian th nghim ph thuc v tng loidu. Khi kt thc th nghim, mnh ng c ly ra, ra sch v sosch vi vi bng tiu chun ASTM v n mn mnh ng t s ktlun y v tnh n mn ca mu du th nghim.3. Tnh chng g, tnh n mn ca duTiu chun xc nh ASTM D 665, ASTM D 1748.- ASTM D 665 c s dng rng ri nhm nh gi kh nng chng g

ca cc loi du khong c cht c ch i vi cc b phn ch tobng st.- ASTM D 1748 c dng nh gi kh nng chng g ca du boqun kim loi trong iu kin m t, c thc hin c thc hintrong t th mu chuyn dng c m cao gi l t m.

Yu cu cc loi du theo quy nh, c kh nng chng g trn giihn ti thiu theo quy nh cho php, trong iu kin s dng theong tiu chun quy nh.

3.1.3.5. Mt s tnh nng khc ca du

1. Tnh n nh xy ho ca duTiu chun xc nh ASTM D 943, ASTM D 2272

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Khoa c kh ng Lc - Trng HSPKT Hng YnASTM D 2893, ASTM D 4742

n nh ca du bi trn biu hin kh nng ca du chng linhng tc ng bn ngoi lm thay i cht lng ca du.2. n nh xy ho, nhit tng hpTiu chun xc nh ASTM D 4871 n nh xy ho - nhit tng hp l mt c tnh quan trng.

N c th nh gi kh nng bn xy ho nhit ca du nhn trongiu kin gn ng thc t s dng. n nh xy ho - nhittng hp c xc nh da vo vic nh gi kt qu phn hu dutrong iu kin th nghim, c ngha l qua mt thi gian tc ngca cc yu t oxy ho, nhit ln du nhn, ngi ta s kim tra li to cn, tr s axit, nht..

Trn c s so snh vi du mi, c th kt lun v kh nng chngli cc tc dng xy ho nhit ca du trong iu kin s dn thc t.3. Tnh to bt ca du

Tiu chun xc nh ASTM D 892.Tiu chun ny dng xc nh to bt bng cch thi khngkh vi mt lu lng nht nh qua mt mu du c gi nhit vthi gian nht nh. o ngay ct bt sau khi ngng thi xc nh to bt ca du (ml). Sau 10 pht lng bt xp xung ngi ta oth tch bt cn li v coi l biu hin ca tnh bn nhit.

3.1.4. Phn loi du bi trn3.1.4.1. Du ng c

1. Phn loi du bi trn ng ca). Phn loi du ng c theo cp cht lngC nhiu cch phn lai du ng c theo cp cht lng nhng ph

bin nht v thun li nht l theo cp cht lng API.Bng di y trnh by s phn loi du bi trn ng c theo cpcht lng l cng trnh chung ca ba t chc: Vin du m Hoa K,Hi k s t v ASTM sut nm 1969 1970.

Bng 3.1.1

STT Nhm Cp du Phm vi ng dng(1) (2) (3)1 Nhm du S S L k hiu ca cp bo d-

ng(Service) dng bi trn ch yung c xng.

1.1 Cp SA - Du nhn khng ph gia- Dng cho ng c xng kiu c- Khng ln dng du cp ny mtcch tu tin, tr khi c hng dn canh sn xut.

1.2 Cp SB - C mt lng ph gia ti thiu chngxy ho v cng kt xc

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- Dng cho ng c xng ti trngnh, kiu c t nm 1930- Khng ln s dng du cp SB trkhi c hng dn.

1.3 Cp SC - Du dng cho ng c xng hotng ti trng cao, thch hp choxe con v xe ti trong giai on 1964- 1967- C kh nng to t cn, chng mimn, g st

1.4 Cp SD - Dng cho cc loi ng c lm victrong iu kin nng, thch hp choxe con v xe ti trong giai on 1968- 1971- C kh nng bo v my tt hn

cp SC1.5 Cp SE - Du c tnh nng tt hn cp SD,chng to cn, bn xy ho cao,chng n mn v chng g tt hn.- Ph hp vi ng c xng 1972 1979

1.6 Cp SF - Dng cho ng c xng lm victrong iu kin nng, dng xngkhng pha ch. Ph hp cc giai on1980 - 1988

- Du c tnh nng tt hn cc loiSC, SD, SE1.7 Cp SG - Du c sn xut t nm 1989, c

coi l du tiu biu dng cho ccng c xng hin nay ca cc loixe con, xe ti v xe du lch.- Du ny t cp CD cho ng cDiesel.- Du SG c th dng thay cho SF, SE,SF/CC, SE/CC v CD

1.8 Cp SH - y l loi du c phm cht cao,ph hp vi cc loi xe con, xe ti snxut t nm 1994 tr li y.- Dng cho ng c xng c yu cuphm cht cao hn SG tng tnhchng to cn, chng xy ho, chngn mn.

1.9 Cp SJ - y l loi du c phm cht caonht hin nay, ph hp vi cc loi xechy xng sn xut t nm 1996 tr liy.- Du cp SJ vt cp SH v tnh nng

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kim sot kh thi, tit kim nhinliu, gim tiu hao du v gim btthi gian bo tr my.

II Nhm du C C l k hiu thng mi (Commer

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