汽车发动机燃烧技术的新进展_英文_

RECENT PRO GRESS IN COM BUST I O N TECHNOLO G IES FO R AUT OMO T IVE ENG INESα

SH I Shao2x i

(N ati onal Engine Com busti on L abo rato ry,T ianjin U niversity,T ianjin300072,Ch ina)

Abstract:A critical review and discussi on on the recent p rogress in com busti on techno logies fo r automo tive engines is p resented.It includes the new techno logies fo r the homogeneous and sto ich i om etric charge com busti on,the p re2 m ixed stratified charge lean com busti on w ith different m ethods of stratificati on(M PF I),the gaso line direct injec2 ti on com busti on(GD I),direct injecti on diesel com busti on(D ID iesel)and the homogeneous charge comp ressi on ig2 niti on com busti on(HCC I).F inally a future p ro spect is given fo r the new com busti on techno logies.

Keywords:atomobile;engine;com busti on techno logy

中图分类号:T K40 文献标识码:A 文章编号:100628740(2001)0120001215

汽车发动机燃烧技术的新进展

史绍熙

(天津大学内燃机国家重点实验室,天津300072)

摘　要:对近年来汽车发动机燃烧技术的各项新进展进行了介绍和评论。内容包括具有理论空2燃比的均质混合气的燃烧,采用不同分层方法的预混合稀薄燃烧(M PF I),直接喷射式汽油机的燃烧(GD I),直接喷射式柴油机的燃烧

(D I D iesel),以及均质混合气压缩点火式发动机的燃烧(HCC I)。最后对这些燃烧新技术的今后发展,进行了展望。

关键词:汽车;发动机;燃烧技术

T he reci p rocating I.C.engines have dom inated the au tom o tive field fo r m any years th rough long and hard com p etiti on s w ith o ther pow ertrain s including steam engines,gas tu rb ines,sto rage batteries and fuel cells.T h is great success of I.C.engines is due to the con tinued i m p rovem en ts in bo th spark ign iti on and com p ressi on ign iti on engines over the years,p articu2 larly over the p ast50years,since they w ere inven ted resp ectivly in1876and189223by N icho las O tto and R udo lf D iesel.Today’s I.C.engines have ou tstanding advan tages of h igh pow er den sity,h igh reliab ility, h igh du rab ility and low co st.If a new pow ertrain has any po ssib ility to rep lace the ex isting I.C.engines,it shou ld no t on ly have the advan tage in pow er den sity over the ex isting I.C.engines,bu t also have the sam e reliab ility and du rab ility as w ell as a reasonab le co st. To reach th is level of developm en t,a trem endou s am oun t of w o rk and ti m e is requ ired.It is expected that I.C.engines w ill likely still reign sup rem e in au2 tom o tive app licati on s fo r the fo reseeab le fu tu re p ro2 vided that their exhau st em issi on s and fuel con sum p2 ti on can be fu rther reduced to m eet the m o re and m o re stringen t em issi on standards and the fuel econo2 m y regu lati on s w h ile keep ing h igh engine p erfo r2 m ance.In o rder to reach th is goal,an ex ten sive re2 search and developm en t w o rk has been carried ou t in recen t years to i m p rove fu rther the engine com bu s2 ti on techno logies.A s a resu lt som e p rom ising resu lts

第7卷(2001)第1期

燃　烧　科　学　与　技　术

JOURNAL OF COM BUSTI ON SC I ENCE AND TECHNOLOG Y

V o l.7(2001)N o.1

α收稿日期:1998211217;修回日期:1998212224。

作者简介:(1916-2000),男,博士,中国科学院院士,天津大学教授。

as w ell as som e dram atic i m p rovem en ts have been ach ieved .T h is p ap er describes and discu sses som e of these

new com bu sti on techno logies fo r bo th S .I .and C .I

.engines .1　Hom ogeneous and Sto ich iom etr ic

Charge S

.I .Com bustion Technolog ies Hom ogeneou s and sto ich i om etric charge com bu s 2

ti on is u sed w idely in conven ti onal spark ign iti on en 2gines .Its great advan tage is that the 32w ay catalyst can be em p loyed to reduce the exhau st em issi on s (CO ,HC and NO x ).How ever ,it can no t bu rn lean m ix tu re to ach ieve h igh fuel econom y .In o rder to i m 2p rove bo th ther m al efficiency and exhau st em issi on s w h ile keep ing h igh engine perfo r m ance ,vari ou s com 2bu sti on techno logies have been investigated and de 2velop ed du ring recen t years .Som e of them are de 2scribed below .

1.1　Tu m ble and I ncl i ned Swirl

To i m p rove the com bu sti on p rocess in a S I en 2gine ,an in 2cylinder air flow of h igh tu rbu lence in ten 2sity and s m all scale tu rbu lence is requ ired .Since the s m all scale tu rbu lence is sub ject to dissi p ati on ,in o r 2der to keep as m uch as po ssib le the in ten se tu rbu 2lence w ith s m all scale up to the com bu sti on p rocess ,it is necessary to supp ly m o re k inetic energy to the air flow du ring the in take p rocess and to reserve it by m ain tain ing large scale vo rtices w h ich are then b ro 2ken up in to s m all eddies w ith h igh tu rbu lence in ten si 2ty befo re the comm encem en t of com bu sti on .

T he large scale vo rtex no r m ally u sed is the s w irl

m o ti on w h ich ro tates around the ax is of the cylinder .R ecen tly a new typ e of large 2scale air m o ti on called tum b le w as discovered in the cylinder of a 42stroke &42valve S I engine w ith a p en troof com bu sti on cham 2

ber .It is also called barrel m o ti on o r vertical s w irl .T h is m o ti on ro tates around an ax is perp endicu lar to

cylinder ax is (F ig .1).It fo r m s du ring the later p art of the in take stroke o r early part of the com p ressi on stroke .It b reak s up in to s m all eddies befo re the com 2m encem en t of com bu sti on ,and bo th the tu rbu lence in ten sity and the tu rbu lence k inetic energy reach

their p eak values (F ig .2)[1]

.T he com bu sti on rate is gine p erfo r m ance are con siderab ly i m p roved

.

F ig .1　For mation of tu m ble m otion

F ig .2　Var i ation of average turbulence k i netic energy

i n cyli nder dur i ng co m pression stroke

F rom the resu lts of a theo retical analysis based upon the p rinci p le of the con servati on of angu lar m o 2m en tum of the in take air flow du ring the inducti on p rocess together w ith the resu lts of bo th the steady flow test rig and the LDA m easu rem en t in the cylin 2der of a m o to red engine carried ou t at T ian jin U n iver 2sity ,a m odel fo r p redicting the speed of tum b le m o 2ti on in a 42valve cylinder S I engine w as ob tained .

R t =Π(Ε-1)Γv Ε S 2

∫

Π0N t Υd z (Η

)d Η2d Η

w here

R t —tum b le rati o (tum b le speed engine speed )

Ε—com p ressi on rati o of engine Γv —vo lum etric efficiency of engine Η—crank angle

R t =

n s ?V s

30?Q s

n s —sp eed of anem om eter vane (r m in ) V s —engine cylinder disp lacem en t (m 3) Q s —air flow rate th rough test rig (m 3 s ) z —p iston travel (m )

?2?燃 烧 科 学 与 技 术 第7卷第1期

d z d x =S (12sin Η+Κ4

sin 2Η) Κ=r L =crank radiu s length of connecting rode

Υ—w indow functi on w hen Η≤Α,Υ=0

w hen Η>Α,Υ=1 Α—critical crank angle

T he resu lts of an LDA m easu rem en t show that the tum b le rati o ob tained by the above p redicting fo r 2m u la is abou t 16%h igher than the value ob tained by the LDA m easu rem en t .T hough the discrep ancy is large ,it is still u sefu l fo r rough esti m ati on and com 2p arison pu rpo ses .

W hen tum b le and s w irl m o ti on s occu r in the cylinder si m u ltaneou sly ,an inclined s w irl m o ti on w ith its ax is of ro tati on inclined to the ax is of the cylinder is fo r m ed .It m ay be con sidered as a com 2b ined m o ti on of s w irl and tum b le .

A s regards the differences betw een tum b le and s w irl in the effectiveness in i m p roving com bu sti on ,

the resu lts of som e investigato rs [2]

indicate that the tum b le gives m ax i m um tu rbu lence in ten sity befo re TDC ;bu t in its tu rbu lence structu re abou t 80%are com ponen ts of low frequencies (below 500H z ).How 2ever ,the to tal tu rbu lence energy of tum b le m o ti on is h igher than that of s w irl m o ti on .T herefo re tum b le m o ti on shou ld have greater effect on the i m p rove 2m en t of com bu sti on than s w irl m o ti on .

Since in the tu rbu lence structu re p roduced by s w irl ,there are m o re h igh frequency com ponen ts ,the inclined s w irl has been found to be very effective to

i m p rove the com bu sti on p rocess [3]

.

F ig .3show s the effects of tum b le and s w irl

on

F ig .3　Effects of tu m ble and swirl on turbulen t to

lam i nar f lam e speed ratio (FSR )

the tu rbu len t to lam inar flam e speed rati o (FSR ).

D ifferen t engine m anufactu rers u se differen t large scale vo rtices to p reserve k inetic energy fo r con 2verting in to tu rbu lence near the end of com p ressi on stroke ,w h ich is requ ired to ach ieve stab le com bu sti on in lean 2bu rn conditi on s .M itsub ish i and Subaru em 2p loy tum b le ,N issan Toyo ta and M azda u se inclined s w irl and Honda u ses s w irl as the large 2scale vo rtices to p reserve k inetic energy .

1.2　Exhaust Ga s Rec ircula tion (EGR )

EGR is an i m po rtan t techno logy fo r i m p roving exhau st em issi on s and fuel econom y and has been w idely u sed .It has been p roven to be an effective m ean s fo r reducing NO x em issi on th rough reducti on of the peak flam e tem peratu re .EGR can also give a sign ifican t reducti on in fuel con sum p ti on under cer 2tain conditi on s .T he am oun t of EGR that can be to l 2eratd in an engine is li m ited by the com bu sti on in sta 2b ility .

G .L um sden et al .ob tained the fo llow ing resu lts of tests carried ou t on a fou r 2stroke S I engine w ith

h igh charge activity [4]

:

1)W ith a sto ich i om etric charge ,a m oderate am oun t of EGR p rovides excellen t NO x con tro l and s m all bu t sign ifican t reducti on in fuel con sum p ti on .A th ree 2w ay catalyst m ay also be u sed w h ile runn ing w ith EGR .O n the average ,10%EGR gives a 70%reducti on in NO x and 24%increase in HC em issi on s . 2)A h igh rate of EGR (>25%)m ay be to lerat 2ed ;bu t ,no r m ally ,it is no t a good ju stificati on fo r u s 2ing such h igh rates of EGR .I m p rovem en t in fuel e 2conom y beyond 10%EGR is s m all and HC em issi on s start to rise m o re rap idly .

3)W ith EGR ,cycle 2to 2cycle variati on of the com bu sti on p rocess is h igher com pared w ith the op er 2ati on w ithou t EGR .

EGR techno logy fo r diesel engines has been studied also in vari ou s investigati on s .T he fo llow ing are b rief ou tlines of the findings .

1)EGR has the effect of reducing the flam e tem 2peratu re due to the increase of heat capacity of the cylinder m ix tu re .It is therefo re an effective w ay to reduce NO x em issi on s .

2).

?

3?2001年2月 史绍熙:汽车发动机燃烧技术的新进展

How ever,in certain cases,it m ay also reduce PM p robab ly due to the dilu ti on of the in take m ix tu re by CO2.

3)EGR influences ign iti on delay in tw o oppo site w ays.T he increase in average in take tem peratu re re2 duces ign iti on delay,w h ilst the reducti on in O2con2 cen trati on due to dilu ti on w ith CO2and N2increase ign iti on delay.T he latter effect is generally the m ajo r one.

4)EGR at low rates and at low loads has on ly a m ino r effect on sp ecific fuel con sum p ti on.

5)T he effect of EGR on flam e sp eed is m uch greater than air.A s m all am oun t of EGR leads to a rap id increase in com bu sti on du rati on.

C.A rcoum an s et al.conducted an investigati on in to the effect of EGR on com bu sti on in a fou r2cylin2 der,op tical,

D.I.VW diesel engine u sing tw o2co lo r m ethod and p ressu re analysis[5].T he resu lts show that

1)T he co re tem peratu re of the flam e is abou t 2230K at0%EGR.Increasing EGR reduces the co re flam e tem p eratu re abou t50K2100K on average de2 p ending on engine operating conditi on s.

2)Increasing EGR tends to delay and reduce the overall fo r m ati on of soo t;bu t at a h igh load,on ly re2 ducti on is ob served.

3)U nder idle conditi on s,EGR has no app reciatle effect on soo t ox idati on,bu t at low loads increasing EGR leads to a reduced rate of soo t ox idati on.

4)Increasing EGR resu lts in an increase in the cyclic variati on of tem peratu re and soo t concen trati on distribu ti on s.

5)T he start2up cycle p ressu re variati on s are in2 creased w ith the increasing EGR rate,speed and load.

In sho rt,EGR has been p roven to be a co st2ef2 fective techno logy fo r reducing NO x and fuel con2 sum p ti on.T here are still a num ber of questi on s con2 cern ing the detailed m echan is m s w h ich affect the com bu sti on speed,soo t fo r m ati on,NO x fo r m ati on,cy2 cle2to2cycle variati on of com bu sti on,fuel con sum p2 ti on,ign iti on delay,sp ray fo r m ati on and its character2 istics,m ax i m um cylinder p ressu re and rate of p res2ed.

2　Stra tif ied Charge and L ean Burn

Com bustion System

T he effo rts fo r bo th h igher fuel econom y and low er exhau st em issi on s led to the developm en t of vari ou s types of stratified charge engine.In conven2 ti onal gaso line engines the range of ign itab le m ix tu re rati o(air fuel rati o)is10∶1to20∶1.T he sto ich i o2 m etric rati o is14.6∶1.H igh com p ressi on rati o lean2 bu rn engines can ign ite m ix tu res w ith an air fuel ra2 ti o up to25∶1.T he stratified charge engines have the po ssib ility to ign ite lean m ix tu res leaner than50∶1.T he p rinci p le fo r stratified charge engines is to have m ix tu re w ith an air fuel rati o clo se to sto ich i o2 m etric value in the vicin ity of the sp ark p lug,and a m uch leaner m ix tu re in the rem ain ing m ajo r parts of the com bu sti on cham https://www.wendangku.net/doc/ec10006845.html, bu sti on starts in the ig2 n itab le m ix tu re and the flam e travels to the regi on of lean m ix tu re.A n exam p le of earlier stratified charge com bu sti on cham ber is the T exaco Con tro led Com2 bu sti on System(TCCS)(F ig.4)w h ich is a direct in2 jecti on type and w as p ropo sed by B arber in1946.T he Honda CV CC(Com pound V o rtex Con tro lled Com2 bu sti on)is a typ ical exam p le of the divided cham ber stratified charge com bu sti on system developed in 1978(F ig.5).T he A F rati o reached23∶1.It is the first stratified charge engine w h ich en tered fu ll p ro2 ducti on.

D u ring recen t years,fu rther effo rts have been m ade on the developm en t of stratified charge lean bu rn com bu sti on techno logy and a great p rogress has been ach ieved.A cco rding to the m ethod of app roach fo r charge stratificati on,the com bu sti on system m ay be classified as ax ial,radial and lateral stratificati on lean bu rn system s.

2.1　Ax i a l Stra tif ica tion L ean Com bustion

Technology

In th is k ind of com bu sti on system,the stratifica2 ti on is ach ieved ax ially by a strong in2cylinder s w irl m o ti on together w ith a fuel in jecti on(po rt in jecti on) at the later part of the in take stroke.T he ign itab le m ix tu re is fo r m ed at the upper part of the cylinder

.

?

4

?燃 烧 科 学 与 技 术 第7卷第1期

F ig .

5　Honda CVCC co m bustion syste m

F ig .4　TCCS co m bustion syste m

be m ain tained up to the end of com p ressi on stroke as show n in F ig .6.A n experi m en t w as conducted in th is w ay at N EC L abo rato ry of T ian jin U n iversity on a 42valve exp eri m en tal engine w ith a Sw irl Con tro l V alve in one in take po rt .W hen clo sing the SCV ,a strong s w irl m o ti on w ith a s w irl rati o of 2.5w as ob tained and thu s an ax ial stratificati on w as successfu lly fo r m ed .T he resu lts show that the engine can op erate satisfacto rily w ith an A F rati o of 23∶1.

In 1992,Honda succeeded in the realizati on of an ax ial stratificati on in a 42valve po rt 2in jecti on S I en 2

gine under part load conditi on s by clo sing one in take valve w ith a variab le s w irl system u sing a valve deac 2tivati on m echan is m (V T EC 2E ).A n air fuel rati o of 22∶1can be u sed .T he b rake specific fuel con sum p 2ti on is reduced by 12%w h ilst retain ing U .S .NO x standard .NO x is reduced to a sufficien t low level by i m p roving the com bu sti on th rough tu rbu lence gener 2ated by s w irl and squ ish and also th rough op ti m um ti m ing of fuel in jecti on .U nder fu ll load conditon s ,the

engine op erates w ith tw o in take valves in the sam e w ay as conven ti onal 42valve engines .NO x is con 2tro lled by a 32w ay catalyst u sing EGR at a sto ich i o 2m etric air 2fuel rati o .T he air 2fuel rati o is con tro lled at 12.5to ob tain m ax i m um pow er ou tpu t [6].2.2　La tera l Stra tif ica tion L ean Com bustion

Technology

Since it w as found that the velocity com ponen t in the directi on of the ax is of a tum b le vo rtex is very s m all ,it can retain stratificati on of m ix tu re layers du ring the w ho le com p ressi on stroke .T h is character 2istic of the tum b le vo rtex m ay be u tilized fo r separat 2ing the rich m ix tu re from the air o r very lean m ix tu re in the p rocess of charge stratificati on .

2.2.1　M itsub ish iM VV P rem ixed L ean B u rn Com 2

bu sti on System (42V alves )

In 1993,the M istsub ish i M o to r Co rpo rati on

m ade i m po rtan t i m p rovem en ts in the M VV p rem ixed

lean bu rn com bu sti on system [7]

.A fou r 2valve versi on w ith

a cen tral locati on of the spark

p lug w as devel 2op ed .A new concep t of T h ree 2L ayer B arrel Stratifica 2ti on w as adop ted (F ig .7).T h is i m p roved com bu sti on system can be app lied to larger disp lacem en t engines

(a )initial stage of intake stroke (b )later stage of intake stroke (c )comp ressi on stroke

F ig .6　Ax i al stratif ication

?

5?2001年2月 史绍熙:汽车发动机燃烧技术的新进展

F ig .7　Concept of three -layer barrel stratif ication

and ex tends the lean bu rn operating range to h igher engine speeds ,In each in take po rt a vertical p artiti on is p rovided up stream of the in take valve stem .Fuel is in jected betw een these partiti on s so that the m ix tu re en ters the cylinder in the inner po rti on and the air en 2ters in the ou ter po rti on to fo r m th ree layers of charge stratificati on .T hu s a richer m ix tu re is fo r m ed at the cen tral part of the com bu sti on cham ber w here the spark p lug is located and a lean m ix tu re is fo r m ed at the ou ter p art of the cylinder .T he p iston top has a cu rved su rface p arallel to the bo ttom su rface of the tum b le vo rtex at BDC so that the upw ard flow veloci 2ty is increased due to the p iston su rface and the tum 2b le m o ti on is thereby enhanced .T he cu rved p iston top also has the effect of supp ressing m isfire by the reducti on of bu lk flow velocity .

B roadly sp eak ing ,in o rder to i m p rove engine

com bu sti on ,to p roduce un ifo r m ly distribu ted eddies

and tu rbu lence is requ ired du ring com bu sti on ,w h ile the bu lk flow velocity shou ld be supp ressed .A s the velocity of the bu lk flow is increased w ith the engine speed ,the supp ressi on of the bu lk flow around the spark p lug at the ign iti on ti m ing is particu larly need 2ed at h igher engine speeds to p reven t the engine from m isfiring .T he m easu res taken by M itsub ish i m en 2ti oned above are p roven to be effective .2.2.2　R icardo CCV S Com bu sti on System

B efo re an efficien t lean bu rn catalyst is avail 2ab le ,it is difficu lt fo r a gaso line engine to m eet bo th the NO x and fuel econom y requ irem en ts .To so lve th is p rob lem ,a successfu l attem p t w as m ade by R icardo by app lying a novel com bu sti on system called Com 2

bu sti on Con tro l by V o rtex Stratificati on (CCV S )[8]

.T he p rinci p le of th is com bu sti on system is to increase the EGR to lerance sub stan tially by stratifying the re 2cycled exhau st gas in the cylinder .Exp eri m en tal re 2su lts show that a con siderab le i m p rovem en t in fuel con sum p ti on m ay be ach ieved in sto ich i om etric condi 2ti on s com pared w ith a conven ti onal versi on of the sam e engine w h ile retain ing U ltra L ow Em issi on V e 2h icle NO x standards th rough the u se of a th ree 2w ay catalyst .T he experi m en tal w o rk w as conducted on a single cylinder engine w ith a pen troof fou r 2valve com bu sti on cham ber to p rovide stratified charge com 2bu sti on .V ery p rom ising resu lts w ere ach ieved w ith th is lateral stratificati on .T he arrangem en t of the lat 2erally stratified CCV S system is given in F ig .8.

T he EGR rate of the CCV S system w as calcu lat 2ed to be abou t 40%under som e conditi on s .W hen the coefficien t of variati on (CoV )of I M EP is 2%,the fu 2el con sum p ti on is i m p roved by 6%～8%and NO x

by

(a )Part load ,low EGR rate ,s w irl ,homogeneous

EGR (b )Part load ,h igh EGR rate ,h igh tum ble ,stratified EGR

F ig .8　M odes of operation of CCVS co m bustion syste m

?6?燃 烧 科 学 与 技 术 第7卷第1期

82%.

A no ther benefit of the CCV S system is that due to the p resence of exhau st gas in crevices ,around o il fil m s and com bu sti on depo sits ,HC em issi on is inher 2en tly low com p ared w ith hom ogeneou s EGR engines .2.2.3　A N ew P rem ixed L ean 2

B u rn S I Com bu sti on

System

A new 52valve per cylinder p rem ixed lean 2bu rn

S I com bu sti on system has been recen tly investigated at N ECL ,T ian jin U n iversity (F ig .9).T he sp ecial featu res of th is techno logy include :

1)3in take valves and 2exhau st valves per cylin 2der

.

F ig .9　Si ngle i n jector with double i n jection

2)Doub le overhead cam shaft (DOHC )valve m e 2chan is m .

3)Cen tral locati on of spark p lug . 4)Fuel in jected to m id 2in take po rt .

5)In each of the tw o side in take po rts ,a s w irl con tro l valve (SCV )is fitted to con tro l the in 2cylin 2der air m o ti on .

6)It can p rovide the requ ired in 2cylinder air m o 2ti on s (tum b le ,s w irl o r inclined s w irl )to ach ieve lean 2bu rn o r sto ich i om etric com bu sti on to m eet the requ irem en ts of differen t load and speed conditi on s th rough varying the op en ing of the SCV and o r the th ro ttle valve as w ell as the ti m ing and quan tity of fuel in jected .It offers h igh flex ib ility of con tro l fo r engine operati on s .

T he experi m en tal resu lts so far ob tained are very p rom ising and show the fo llow ing advan tages of the 52valve p er cylinder lean 2bu rn S I engine com p ared

w ith the o riginal engine CA 1102Q (2valves p er cylinder ,carbu reto r ,A F =14.7).

1)T he idling speed is reduced from 550r m in to

400r m in .

2)Bo th the CO and HC em issi on s at an idling speed (550r m in )are reduced abou t 80%.

3)A t part load (bm ep =0.29M Pa ),b .s .f .c .is reduced by 10.7%.T he lean li m it is A F =22(co rre 2sponding to CoV of 4%i m ep ).

4)A t a m edium load (bm ep =0.4M Pa ),the lean li m it reaches A F =25,b .s .f .c .is reduced by 12.3%w hen A F =18

～23. 5)A t a fu ll load (W O T ),the low speed to rque and m ax i m um pow er ou tpu t are increased by 10%and 10.6%respectively ,w h ilst b .s .f .c .is reduced by 6.8%～23%.

T he w o rk is still go ing on ,and it is expected that the all round p erfo r m ance of the 52valve engine is su 2peri o r to that of the 42valve p rem ixed lean 2bu rn en 2gine w h ich is now also under investigati on at N ECL .

3　Ga sol i ne Eng i ng D irect I n jection

Technology

T he Gaso line direct in jecti on techno logy is the

m o st attractive techno logy fo r its po ten tial of excel 2len t ther m al efficiency and h igh engine perfo r m ance ,and had been con sidered as an ideal engine techno logy fo r 42stroke S I engines fo r m o re than 50years .T he earliest GD I techno logy fo r 42stroke S I engines w as

p ropo sed by E .B arber et al in 1946[9]

.It w as later ap 2p lied by T exaco and w as nam ed T exaco Con tro lled Com bu sti on System (TCCS )(F ig .4)w h ich finally failed to becom e a comm erical p roduct m ain ly becau se of its difficu lty in coo rdinating the fuel in jecti on ti m 2ing ,the sp ark ing ti m ing and the in 2cylinder air m o 2ti on over w ide li m its of loads and speeds .T he great p rogress m ade du ring the past 20years in the areas of com pu tati on flu id dynam ics ,electrical fuel in jecti on ,laser diagno stics of in 2cylinder air m o ti on and com 2bu sti on p rocess ,variab le s w irl and tum b le con tro l etc .p rovides the po ssib ility of overcom ing the techn i 2cal difficu lties encoun tered in the developm en t of GD I techno logy .A b reak th rough of th is techno logy w as first ach ieved by M itsub ish i M o to r Co rpo rati on in 1994.

3.1　M itsub ish i G D I Com bustion Syste m

It con sists m ain ly of [10]:

?

7?2001年2月 史绍熙:汽车发动机燃烧技术的新进展

1)V ertical straigh t in take po rts to generate an in ten se tum b le air m o ti on in the cylinder w ith a direc 2ti on ro tating oppo site to that of the tum b le p roduced

by conven ti onal in take po rts (i

.e .reverse tum b le )(F ig .10)

.

(a )direct injecti on (b )conventi onal po rt injecti on

F ig .10　Generation of i n ten se reverse tu m ble

by upr ight i n t ake port

2)A sp herical com pact p iston cavity to m ain tain charge stratificati on and to con tro l the fuel sp ray be 2havi o r and vapo rized gaseou s m ix tu re (F ig .11)

.

(a )late injecti on (b )early injecti on

F ig .11　Spher ical co m pact cav ity

and behav ior of fuel spray

3)A n electro 2m agnetic low p ressu re s w irl fuel in jecto r (in jecti on p ressu re 5M Pa )to fu lfil the re 2qu irem en ts fo r atom izati on ,penetrati on and disper 2si on of the fuel sp ray .

T he basic techno logy fo r m ix tu re fo r m ati on em 2p loyed in M itsub ish i GD I engine m ay be summ arized

w as fo llow s [11]

:

1)(jected du ring the later stage of the com p ressi on stroke )so as to ach ieve distinct stratificati on of the charge .In th is load range ,the A F rati o is con tro lled at 30to 40.W hen the charge is stratified ,soo t is fo r m ed in the rich zone ,sufficien t excess air shou ld be supp lied to bu rn 2up the soo t .

2)A t h igh loads ,an early in jecti on is em p loyed (fuel in jected )du ring the early stage of the in take stroke so as to ach ieve hom ogeneou s and sto ich i om et 2ric o r sligh tly rich m ix tu re at fu ll load (equ ivalence rati o >1)in o rder to supp ress the soo t fo r m ati on . 3)R ap id and s m oo th s w itch ing of the late and early in jecti on s .

Generally sp eak ing ,the late in jecti on zone is ex 2tended up to 50%load ,so as to have enough excess air in the cylinder to bu rn 2up the soo t befo re exhau st 2ing from the cylinder .W hen the load exceeds 50%,soo t w ou ld be em itted as a diesel engine .T he fuel in 2jecti on shou ld be s w itched from the late m ode to ear 2ly m ode .

T he M itsub ish i GD I engine w as in troduced in to Jap anese m arket in A ugu st ,1996.Since then fu rther research has been conducted and several m odifica 2ti on s have been m ade ,including the reducti on of fuel in jecto r ’s angle of inclinati on to the vertical line to i m p rove the com bu sti on stab ility ,adop ti on of new

“tw o 2stage m ix ing ”techno logy to supp ress the knock at low speeds resu lting in an increase in com p ressi on rati o from 12∶1to 12.5∶1,u sing a new selective re 2ducti on lean 2NO x catalyst w ith i m p roved NO x conver 2si on efficiency ,and em p loying a new “tw o stage com 2bu sti on ”m ethod .A s a resu lt of these m odificati on s ,it is clai m ed that the new versi on of GD I engine

ach ieves 10%h igher to rque and 20%low er s .f .c .than the conven ti onal po rt fuel in jecti on (PF I )w ith exhau st em issi on s capab le of m eeting the Eu rop e and D 3regu lati on s

[12]

.

T here are o ther GD I com bu sti on system s devel 2op ed by Toyo ta ,N issan ,Isuzu ,R icardo ,M ercedes 2B enz ,FEV etc .P rom ising resu lts have also been ach ieved .

3.2　D iscussion s on G D I Technology

A s stated above ,the GD I techno logy has attract 2?8?燃 烧 科 学 与 技 术 第7卷第1期

coun tries due to its theo retical po ten tial of h igh ther2 m al efficiency and h igh engine perfo r m ance.T rem en2 dou s effo rts have been ach ieved in the research and developm en t w o rk of th is techno logy in the hop e that GD I engine m ay becom e a p ri m ary pow ertrain sou rce fo r au tom o tive engine in the near fu tu re.How ever, there are still a num ber of facto rs w h ich have to be fu rther studied:

1)U nbu rned HC in the exhau st gas is sign ifi2 can tly h igher than that of diesel engines.

2)In gaso line engines including GD I engines abou t2%of fuel is escaped from com bu sti on.T h is escaped fuel is several ti m es as m uch as unbu rned HC in the exhau st gas.T h is is due to the low cetane num2 ber of gaso line w h ich can be bu rn t on ly by flam e p ropagati on.T he flam e can hardly reach the fuel in regi on s clo se to the com bu sti on cham ber w all[11].

3)Sp ark p lug ign iti on fou ling cau sed by i m2 p ingem en t of the fuel on the sp ark p lug,and the ef2 fect on the du rab ility of the spark p lug due to the

h igher ign iti on.

4)Op erating techno lgoy fo r“step less”load con2 tro l.

5)In a GD I engine,bo th the m ix tu re and the tem p eratu re distribu ti on are heterogeneou s.NO x is fo r m ed in the fuel2lean and h igh tem peratu re regi on, w h ile so lid p articu lates are p roduced in the fuel2rich and h igh tem p eratu re regi on.T he fo r m ati on of bo th NO x and PM em issi on s are difficu lt to con tro l.

6)A vailab ility and du rab ility of after treatm en t system.

7)It is doub tfu l w hether the advan tages of the GD I engine can offset the additi onal com p lex ity and co st as com p ared w ith the M PF I engine.

8)O verall reliab ility and du rab ility of the GD I engine.

A s regards the p rem ixed lean2bu rn techno logy (M PF I),it is a co st2effective and reliab le m ethod.A l2 though its ther m al efficiency and engine perfo r m ance is inferi o r to GD I engines,it is likely that such en2 gines w ill con tinue to ex ist in the fu tu re m arket,be2 cau se it avo ids the com p lex ity and the exp en se of the GD I engine.Fu rther,a conven ti onal S I engine can be difficu lty.A t p art loads,EGR m ay be u sed to reduce NO x em issi on s.

4　D irect I n jection D iesel Eng i ne Com bustion Technology(D I D iesel Com bu sti on)

4.1　Adava tages of D ID iesel Eng i nes

In the past decade the direct in jecti on com bu s2 ti on techno logy has m ade a great p rogress fo r h igh speed au tom o tive diesel engines in Eu rope.A tran si2 ti on from indirect in jecti on(I D I)to direct in jecti on has been m ade.D I diesels offer an i m p rovem en t in fu2 el econom y of12%～15%over I D I diesels.A D I diesel engine has a ther m al efficiency of25%h igher than a gaso line eingine.T h is h igher ther m al efficien2 cy takes in to accoun t of12%h igher energy per gallon of fuel.A lso it takes abou t5%less energy to p roduce a gallon of diesel fuel from crude o il as com pared w ith gaso line.T hu s by u sing diesel engines,abou t 30%of p etro leum w ou ld be saved.Fu rther,diesel en2 gines have low er CO2,CO and HC em issi on s(from bo th tailp i pe and evapo rati on)com pared w ith gaso2 line engines.D iesel engines p roduce abou t the sam e am oun t of NO x over the veh icle life ti m e(H amm erle, 1994).Em issi on deteri o rati on facto rs(D F)fo r diesel are m uch low er than tho se fo r gaso line engines.Fo r these reason s,diesel engines have gained a cu rren t m arket p ropo rti on of25%～30%in Eu rope.

4.2　D ID iesel Com bustion Syste m

Fo r D I diesel engines,the com bu sti on system configu rati on and its m ajo r com ponen ts have been generally estab lished-Fou r2valve cylinder,cen tral locati on of fuel in jecto rs w ith h igh in jecti on p ressu re, variab le geom etry tu rbo charger(V GT)w ith after2 coo ling,exhau st gas recircu lati on(EGR)system, variab le s w irl con tro l system.

T he fu tu re requ irem en ts are m ain ly related to the i m p rovem en ts of fuel in jecti on and EGR system. T he exhau st gas after treatm en t system also needs to be i m p roved(including D eNO x particu late trap).

4.3　Fuel I n jection Syste m

T he m ajo r task fo r the fu rther developm en t of D I diesel engines is to reduce PM and NO x em issi on s to m eet the fu tu re exhau st em issi on regu lati on s w h ile

.

?

9

?

2001年2月 史绍熙:汽车发动机燃烧技术的新进展

m o st effective m easu res fo r reducing PM are to in 2crease in jecti on p ressu re and to reduce nozzle ho le ar 2eas w h ich are clo sely related

so as to m ain tain the rates of in jecti on .T hese requ irem en ts lead to the p ro 2ducti on of the fo llow ing fuel in jecti on system s

[13]

.

Tab

.1　Fuel i n jection syste m for D I diesel eng i nes M ax .nozzle side p ressure M Pa 140180150135Po tential m ax .nozzle side p r . M Pa

160220

180

165

Injecti on rate

contro l M echanic M echanic E lectronic M echanic

M echanic

E lectronic

Current m ini m um

sp ray ho le area

%100

～92～84～88

H PR P —h igh p ressu re ro tary pum p .

EU I —electron ically con tro lled un it in jecto r (cam driven ). I N T —in ten sifier fuel in jecti on system .

H PCR —h igh p ressu re comm on rail fuel in jecti on system .

A ll the above listed fuel in jecti on system s can m eet E ro em issi on standards up to a veh icle w eigh t of 1800kg .

It shou ld be no ted that as the in jecti on p ressu re and pum p ing capacity of the in jecti on system s are in 2creased (p articu larly fo r the system giving h

igh m ean in jecti on p ressu res )the quan tity of fuel in jected du r 2ing the in itial peri od of in jecti on is relatively large .

T h is fuel m ixes w ith air and bu rn s m o re readily

due to the effect of s m all nozzle ho les ,p articu larly at p art loads ,resu lting in bo th NO x em issi on s and com 2

F ig .12　Co m bi ned application of EGR syste m and HPCR fuel syste m for reduction of NO x and P M

(M undo rff et al .AVL )

bu sti on no ise .NO x can be effectively reduced by EGR ,bu t w ith increased PM w h ich m ay be reduced by increasing in jecti on p ressu re .

T h rough p roperly com b ined app licati on of EGR and h igh in jecti on p ressu re ,bo th NO x and PM can be reduced dram atically as show n in F ig .12at part load conditi on s (a comm on rail fuel system ,m atched w ith a EGR system )

[13]

.

5　Hom ogeneous Charge Com pression

Ign ition Com bustion

Technolog ies —T he T h ird T yp e of Com bu sti on P rocess in I

.C .Engines 5.1　HCC I Concept

T h is is a new and p rom ising com bu sti on techno l 2ogy still under investigati on .T he Hom ogeneou s Charge Com p ressi on Ign iti on p rocess m ay be con sid 2ered as a hyb rid of the traditi onal spark ign iti on and the com p ressi on ign iti on p rocesses .In a sp ark ign i 2ti on engine ,the air 2fuel m ix tu re is hom ogeneou s ,bu t here it is ign ited by com p ressi on in stead of by sp ark p lug .In a diesel engine ,the charge is ign ited by com 2p ressi on ,bu t in HCC I engine the charge is hom oge 2neou s in stead of heterogeneou s .

T he m ain advan tage of a diesel engine over a spark ign iti on engine is that at part load the fuel con 2sum p ti on is m uch low er becau se it can op erate un 2th ro ttled .T he S .I

.engine has the advan tage of h igher pow er den sity com pared w ith a diesel engine due to its m o re efficien t u tilizati on of air resu lting from the hom ogeneou s charge .T herefo re ,HCC I com bu sti on techno logy offers the po ssib ility of having advan tages of bo th diesel and gaso line engines ,w ith h igh ther m al efficiency ,low NO x and low p articu lates .

In the traditi onal com bu sti on p rocess occu rring in a sp ark ign iti on engine a hom ogeneou s air fuel m ix tu re is ign ited by a spark p lug and the flam e fron t ,a narrow reacti on zone p ropagates th rough the hom ogeneou s m ix tu re .T h is type of com bu sti on p ro 2cess is h igh ly uncon tro lled and can on ly be affected to

a li m ited ex ten t by the air m o ti on in the com bu sti on cham ber

[14]

.

D u ring the p ropagati on of flam e ,the local tem 2

?01?燃 烧 科 学 与 技 术 第7卷第1期

p eratu res in the flam e fron t and beh ind it are m uch h igher than tho se in the unbu rned m ix tu re.T hu s the com bu sti on p rocess and the tem peratu re distribu ti on are h igh ly heterogeneou s although the air m ix tu re is hom ogeneou s.T he local h igh tem p eratu re leads to the fo r m ati on of NO x in the po st2flam e regi on.

In a diesel engine,the com bu sti on is of diffu si on type in w h ich the rate of chem ical reacti on is m uch h igher than the rate of m ix ing.T herefo re the rate of com bu sti on is con tro lled by the m ix ing rate.T he ign i2 ti on takes p lace at m any po in ts.In th is typ e of com2 bu sti on,bo th the m ix tu re and the tem peratu re distri2 bu ti on are heterogeneou s.NO x is p roduced in the fu2 el2lean and h igh tem p eratu re regi on and w h ile so lid p articu lates are fo r m ed in the fuel rich and h igh tem2 p eratu re regi on.T h is typ e of com bu sti on is also diffi2 cu lt to con tro l in relati on to tox ic em issi on s.

F rom the above discu ssi on s,it is clear that the fundam en tal p rob lem occu rring in bo th traditi onal types of com bu sti on is the heterogeneou s tem peratu re distribu ti on w ith h igh local tem peratu re and low bu lk average tem p eratu re.

In the HCC I p rocess,theo retically,a hom oge2 neou s air fuel m ix tu re and residual gases are ign ited by com p ressi on th roughou t the w ho le m ix tu re.T he com bu sti on takes p lace spon taneou sly and hom oge2 neou sly w ithou t flam e p ropagati on.T he fo r m ati on of p articu lates and NO x can thu s be p reven ted.T h is is the fundam en tal concep t of HCC I.In th is p rocess, there are tw o m ajo r p rob lem s,nam ely the con tro l of the in itiati on of ign iti on and the con tro l of the rate of com bu sti on over the w ho le engine operating range. 5.2　A Br ief Rev iew of Prev iousW ork

HCC I has vari ou s nam es.In th is pap er a un ified nam e HCC I is u sed to avo id m isunderstandings.HCC I fo r tw o2stroke engines w as first studied by O n ish i et al.in1979[15].T hey found HCC I com bu sti on can be realized in a tw o2stroke engine at low loads over a w ide range of engine sp eed(1000～4000r m in)w ith m uch better com bu sti on stab ility than that in the conven ti onal engine.T he fuel econom y and exhau st e2 m issi on s w ere app reciab ly i m p https://www.wendangku.net/doc/ec10006845.html, bu sti on w as in itiated at m any po in ts by au to2ign iti on,bu t there of these po in ts.N o flam e p ropagati on w as ob served as in a conven ti onal S I engine.T he com bu sti on rate of the w ho le m ix tu re w as low er com pared to that in the conven ti onal S I engine.L ater in the sam e year, N oguch i et al pub lished the resu lts of their exp eri2 m en tal study on HCC I in an oppo sed2p iston tw o stroke engine[16].T he com bu sti on phenom ena ob2 served w ere the sam e as tho se ob tained by O n ish i et al.V ery stab le com bu sti on w as ach ieved w ith low er fuel con sum p ti on and low er HC em issi on s.HCC I p ro2 cess cou ld take p lace betw een800～3200r m in and w ith an air fuel rati o of11～22.A n experi m en tal w o rk carried ou t by Iida in1994found that by u sing m ethano l as fuel in a tw o2stroke engine,the operating range fo r stab le HCC I com bu sti on cou ld be con sider2 ab ly ex tended[17].

N jat and Fo ster first ach ieved HCC I com bu sti on in a fou r2stroke engine[18].T he test engine u sed w as a CFR engine w ith a variab le com p ressi on rati o and sh rouded in take valve u sing a m ix tu re of iso2octane and n2hep tane as the fuel.Several com p ressi on rati o s w ere tried.A h igher com p ressi on rati o cou ld allow a low er charge gas tem peratu re,bu t it resu lted in an excessive heat release.It w as found that a com p res2 si on rati o of7.5w as satisfacto ry and the in take tem2 peratu re w as480～800K.T he average heat release rates w ere con siderab ly h igher than tho se ob tained by O n ish i and N oguch i in tw o2stroke engines.

　T h ring is the first investigato r w ho suggested a fou r stroke passenger car engine to u se HCC I at idle and ligh t loads to ach ieve h igh fuel econom y like diesel,and to s w itch to conven ti onal gaso line engine op erati on at fu ll pow er fo r good specific pow er ou t2 pu t[19].T he resu lts of h is exp eri m en ts confir m ed that HCC I com bu sti on can take p lace in a fou r stroke en2 gine and under righ t conditi on s(Υ=0.45,EGR= 20%～26%),giving a fuel econom y com parab le w ith the D.I.diesel engine(isfc=180～200g k W h).It w as also confir m ed that HCC I com bu sti on requ ires h igh EGR rates(13%～33%)and h igh in take tem2 peratu res(>370°C).

T he first to study HCC I com bu sti on p rocess on a real p roducti on engine w as Stock inger et al.in 1992[20].1.6

?

1

1

?

2001年2月 史绍熙:汽车发动机燃烧技术的新进展

verted to HCC I m ode.A com p ressi on rati o of18.4 w as u sed.T he in take air w as p reheated up to180℃. T est resu lts show ed that the part load efficiency w as increased from14%to34%.HC em issi on s w ere re2 duced from700×10-6to200×10-6.

In1996,A oyam a et al conducted an exp eri m en tal study on p rem ixed2charge com p ressi on ign iti on gaso2 line engine(PCC I Engine)[21].It w as con sidered that an engine p rovided w ith p rem ixed lean m ix tu re,h igh com p ressi on rati o and m u lti2po in t spon taneou s ign i2 ti on w ou ld be ideal fo r ach ieving bo th better fuel e2 conom y and low er NO x.A test engine called PCC I en2 gine w as u sed w ith in let po rt in jecti on of gaso line.A series of exp eri m en ts w ere conducted on engines of the sam e bo re and stroke bu t w ith th ree differen t com bu sti on system s:1)D I diesel;2)D I com p ressi on ign iti on gaso line;and3)PCC I(HCC I).T he com p res2 si on rati o s of the fo r m er tw o w ere17.6and that of PCC I w https://www.wendangku.net/doc/ec10006845.html, parison tests w ere carried ou t fo r these th ree com bu sti on system s.T est resu lts show ed that in the A F rati o range(33～44)of stab le com bu sti on,PCC I(HCC I)ach ieved equ ivalen t fuel e2 conom y and m uch low er NO x em issi on com pared w ith D I diesel engine,bu t HC em issi on s w ere h igher.A t an A F rati o of40,NO x of D I com p ressi on ign iti on gaso2 line engine is h igher than tho se of bo th D I diesel and PCC I(HCC I)engines.

In take air heating(29～172℃)and supercharg2 ing(charge efficiency up to110%)w ere em p loyed to ex tend the stab le operating range of the PCC I en2 gine.Bo th ach ieve sign ifican t effects.A stab le op era2 ti on w as ach ieved even at an A F rati o of80w ith an in take air tem p eratu re of172℃.

In1997Ch risten son et al conducted an investiga2 ti on on HCC I com bu sti on in a1.6liter,single cylin2 der,fou r stroke engine w ith a fixed com p ressi on rati o of21∶1[22].A hom ogeneou s charge w as u sed as in an S I engine bu t the charge w as com p ressed to au to2ig2 n iti on as in a diesel.T he characteristics of HCC I op2 erati on w ere com pared w ith tho se of S I operati on w ith a com p ressi on rati o of12∶1.T h ree differen t fu2 els of iso2octane,ethano l and natu ral gas w ere u sed, having octane num bers of100,107and120respec2 .tests.T h ree in let air tem peratu res of80℃,100℃and120℃w ere selected(40℃w ithou t p reheating).

A ir w as u sed as the dilu ti on fo r ach ieving h igh dilu ti on of the m ix tu re requ ired fo r HCC I.T he am oun t of dilu ti on w as exp ressed as the A F equ iva2 lence rati oΚ.A stab le and efficien t HCC I operati on w as ob tained w ithΚ=3to9fo r isooctane and ethano l.N atu ral gas w ith a h igh octane num ber re2 qu ired a richer m ix tu re w ithΚ=2.5～3.5fo r HCC I com bu sti on operati on.

Exp eri m en tal resu lts show ed that HCC I cou ld be realized w ith all the th ree fuels u sed.W hen isooctane w as u sed,the engine cou ld be operated un th ro ttled w ithou t p reheating w ith a com p ressi on rati o of21∶1.E thano l requ ired an in let air tem peratu re of80℃and natu ral gas requ ired120℃fo r HCC I operati on w ith the sam e com p ressi on rati o.T he i m ep in the sta2 b le load range w as(1～5)×100kPa.T he indicated efficiency of HCC I w as m uch h igher than that of S I op erati on.V ery little NO x w as p roduced,indicating the po ssib ility of w ithou t the need of D eNO x catalyst. How ever,HC and CO generated w ith HCC I w ere bo th h igher than tho se from S I operati on[22].

Earlier studies on HCC I operati on indicated h igh efficiency and very low NO x,bu t HC&CO w ere h igher than tho se from S I operati on,and i m ep w as low,being li m ited to5×100kPa.In1998Ch risten son et al.carried ou t an experi m en tal study on sup er2 charged HCC I[23].H ere again,the sam e th ree fuels m en ti oned above w ere u sed.T he resu lts show ed that the h ighest i m ep ob tained w as1.4M Pa u sing natu ral gas as fuel.T he boo st p ressu re w as0.2M Pa and the com p ressi on rati o w as17∶1w hen the peak cylinder li m it w as25M Pa.T he HC em issi on w as reduced as the boo st p ressu re and engine load w ere increased. Ex trem ely little NO x w as generated in all cases.T he CO em issi on depended on the A F rati o and p reheat2 ing.W hen the m ix tu re w as clo se to the rich li m it and w ith ho t in let air,little CO w as generated.

O ne of the latest experi m en tal w o rk on HCC I w ith single fuel(diesel)under heavy load conditi on s w as carried ou t by Suzuk i et al[24].T he test engine w as a single cylinder fou r stroke D.I.diesel engine

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com p ressi on rati o of20.4.T he s w irl rati o w as1.9.A fuel in jecto r w ith an in jecti on p ressu re of5M Pa o rig2 inally u sed fo r GD I engines w as app lied here to sup2 p ly p rem ixed fuel to p roduce a hom ogeneou s fuel air m ix tu re in the in take system.A no ther fuel in jecto r w ith an in jecti on p ressu re of18M Pa w as u sed fo r in2 jecting a s m all am oun t of fuel directly in to the cylin2 der.H ere bo th the p rem ixed fuel and the D I fuel w ere diesel(In their p revi ou s w o rk,iso2octane w as u sed fo r p rem ixed fuel to avo id uncon tro lled au to2ign iton,bu t the u se of dual fuels si m u ltaneou sly is no t p ractical). U nder certain conditi on s,a supercharger w ith in ter2 coo ling and w ith a charging p ressu re up to40kPa w as u sed fo r ach ieving a leaner m ix tu re.T he exp eri2 m en tal resu lts are as fo llow s.

1)In HCC I com bu sti on p rocess u sing single fu2 el,a h igh p rem ixed fuel rati o(p rem ixed fuel to tal fu2 el)is requ ired to reduce bo th NO x and PM si m u ltane2 ou sly,bu t the m ax i m um value of the p rem ixed rati o is li m ited by the engine load.

2)A t low loads(e.g.40%load),it is po ssib le to operate the engine w ith large p rem ixed fuel rati o s to reduce bo th NO x&PM em issi on s,bu t HC and s.f.c. are increased as the p rem ixed fuel rati o is increased. U nder h igher load conditi on s,at75%load,knock oc2 cu rs w hen the p rem ixed fuel rati o is≥80%.A t fu ll load,knock takes p lace w hen the p rem ixed fuel rati o is≥60%.

3)M o st NO x w as found to be from the com bu s2 ti on of D I fuel and it cou ld be reduced by op ti m izing the in take charge p ressu re and D I fuel in jecti on ti m2 ing.Sup ercharging can i m p rove bo th NO x and PM at

h igh p rem ixed fuel rati o s.

5.3　Su mmary

1)In summ ary,the resu lts of p revi ou s studies on HCC I com bu sti on show its po ten tial of h igh efficien2 cy,low NO x and PM em issi on s and low cycle2to2cycle variati on s,and the am oun t of NO x em issi on m ay be reduced to negligib le s m all(on ly a few ppm under certain op erating conditi on s).T h is offers the po ssi2 b ility of w ithou t u sing the lean bu rn D eNO x catalyst.

A ll these po ten tial advan tages of HCC I are m o st at2 tractive.

2)du ring the w ho le operating range of an engine,a large am oun t of research w o rk has been conductd in bo th tw o2stroke and fou r2stroke engines u sing bo th liqu id and gaseou s fuels.How ever,on ly li m ited success w as ach ieved[14].T he li m itati on is m ain ly due to the diffi2 cu lties in con tro lling the ign iti on and the com bu sti on rate over the w ho le engine operating range.

3)HCC I engines of fou r2stroke have no t been ab le to op erate under conditi on s o ther than low load and low speed,w ith an i m ep no t exceeding0.5M Pa fo r natu ral asp irated engines[19,23].How ever,tw o2 stroke engines operating in HCC I m ode can develop reasonab le pow er ou tpu t due to the m uch h igher in2 ternal EGR than fou r2stroke engines.

4)T he effect of HCC I on HC em issi on s is no t yet clear.Fo r tw o2stroke engines w ith HCC I com bu s2 ti on m ode,HC are sign ifican tly reduced under p art load conditi on s.Fo r fou r2stroke engines,Stock inger et al.show ed a reducti on of HC from700×10-6to 200×10-6by changing S I com bu sti on m ode to HCC I. How ever,A oyam a et al.show ed a m uch h igher HC e2 m issi on fo r HCC I engines than D I diesel engines and

D I gaso line engines.

5)Sup ercharging is an effective m ethod to ex2 tend the range of the stab le com bu sti on and to in2 crease the i m ep of the HCC I op erati on.T he i m ep of a natu ral gas engine u sing HCC Im ay be increased to1. 4M Pa by sup ercharging.

5.4　D iscussion s

F rom the resu lts of p revi ou s studies,the m ajo r facto rs con tro lling HCC I com bu sti on p rocess m ay be summ ed up as fo llow s.

1)D ilu ti on of in take m ix tu re

T he dilu ti on of the m ix tu re shou ld be h igh enou2 gh to slow dow n the rate of com bu sti on to avo id un2 con tro lled com bu sti on.T he h igh dilu ti on m ay be ach ieved by a h igh A F rati o o r a h igh EGR rati o. Fo r fou r2stroke engines,u ltra2lean m ix tu res o r large am oun t of EGR m u st be em p loyed becau se the resid2 ual gas is m uch less than tw o2stroke engines.

2)Com p ressi on rati o

T he com p ressi on rati o fo r HCC I shou ld be h igh enough to in itiate ign iti on bu t no t too h igh to p reven t

.

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2001年2月 史绍熙:汽车发动机燃烧技术的新进展

no r m ally requ ired w hen u sing diesel fuel to avo id ear2 ly au to2ign iton.

3)In take tem p eratu re

HCC I com bu sti on p rocess requ ires h igh in take tem p eratu re.T he degree of m ix tu re p reheating de2 p ends on the typ e of fuel u sed,com p ressi on rati o,A

F equ ivalence rati o and in let p ressu re.

4)Sup ercharging(see summ ary5)

5)T i m e of ign iti on

N o r m ally HCC I com bu sti on can be ach ieved in a 42stroke engine w hen ign iti on takes p lace w ith in abou t20℃A befo re TDC.If ign iti on occu rs after TDC,the com bu sti on is deteri o rated and m isfiring oc2 cu rs due to the reducti on in tem p eratu re in the com2 bu sti on cham ber.

6)Engine load

U nder very low load conditi on s,HCC I com bu s2 ti on can hardly be ach ieved becau se the m ix tu re tem2 p eratu re is too low.U nder very h igh load conditi on s, the HCC I concep t is also no t successfu l due to in suf2 ficien t quan tity of residual gases.HCC I com bu sti on is po ssib le betw een these tw o ex trem e regi on s p rovided that all the con tro l facto rs are p rop erly coo rdinated.

It is also difficu lt to ach ieve HCC I at h igh engine speeds fo r42stroke engines.

7)T yp e of fuel u sed

D ifferen t fuels have been tested in HCC I op era2 ti on including gaso line,diesel fuel,iso2octane, m ethano l,ethano l and nati onal gas.Experi m en tal re2 su lts show that a h igh octane num ber is benficial to the successfu l op erati on of HCC I[11].Ch risten sen et al.show ed that w hen fuels of h igh octane num bers (100～120)w ere u sed in HCC I op erati on,h igh indi2 cated ther m al efficiency(com parab le to diesel engine)and a negligib le am oun t of NO x w as ob2 tained.

T h is h igh efficiency m ay be attribu ted to:1)very lean m ix tu reΚ=3～9;2)h igh com p ressi on rati o(21∶1);and3)un th ro ttled operati on of HCC I.

T h is u ltra2low NO x is due to the very lean m ix2 tu re and the hom ogeneou s com bu sti on w h ich gives a very low cycle tem p eratu re.T h is can be exp lained by the fo llow ing equati on given by H eyw ood based on

[25]. d[NO]

d t

=6×1016T-12exp

-69090

T

[O2]1 2[N2] It can be show n that NO starts to fo r m at1800 K and increases rap idly.It agrees qu ite w ell w ith Ch risten son’s experi m en tal resu lts[19].T h is indicates that the HCC I com bu sti on takes p lace at a tem pera2 tu re low enough to p reven t the fo r m ati on of NO x.O n the o ther hand,it gives the draw back s of h igh un2 bu rned HC and CO and also the li m ited i m ep.How ev2 er,HC can be ox idized by a catalyst even if the ex2 hau st tem peratu re is low du ring lean operati on,and the i m ep can be increasd by sup ercharging.

A ll the con tro l facto rs m en ti oned above are no t on ly clo sely related bu t also affect each o ther.

6　Future Prospect

1)It is m o st likely that the p rem ixed lean2bu rn engine w ith EGR w ill con tinue to be u sed du ring p e2 ri ods w hen the GD I engine has becom e dom inan t in the au tom o tive field.

2)T he GD I engine m ay becom e the p ri m ary pow er p lan t fo r cars and o ther ligh t veh icles from the p eri od2010～2020.

3)T he general accep tance of the direct in jecti on diesel engine in Eu rope as a du rab le,efficien t and en2 vironm en t2friendly engine has resu lted in a cu rren t m arket penetrati on of25%～30%.It m ay be exp ect2 ed that the D I diesel engine m arket w ill con tinue to grow no t on ly in Eu rope,bu t also in Japan,U.S.A. and o ther coun tries.

4)It is difficu lt to p redict the ti m e of com p lete realizati on of the HCC I engine concep t,bu t befo re th is goal is reached,the dual m ode op erati on m ay be em p loyed fo r fou r2stroke passenger car engines.T hat is,conven ti onal S I gaso line operati on is u sed at start2 up and at h igh loads,and s w itch to HCC I op erati on at idle and ligh t loads.T hen the engine w ou ld have the advan tages of h igh pow er ou tpu t and low PM of a gaso line engine.It w ou ld also have the good part2load and idle fuel econom y of a diesel engine,bu t w ith m uch qu ieter operati on.

References:

[1]　Sh i S X,L i Y F,et a l.A Study of T um ble and Sw irl M o ti ons and

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T heir Effects on Com busti on in a Four V alve S I Engine [A ].P roc A SPA CC 1997.

[2]　L e Coz J F,et a l .A n Experi m ental and Computati onal F low and

Com busti on in a 42valve S I Engine 2Focus on Cycle 2R eso lved T ur 2bulence[A ].SA E Paper 900056.

[3]　A rcoum anis C ,et a l .F requency A nalysis of T ur m ble and Sw irl in

M o to red Engines [J ].Part D ,I M echE ,1991.

[4]　L um sden G .Comparing L ean Burn and EGR [A ].SA E Paper

970505.

[5]　A rcoum anis C .Effect of EGR on Com busti on D evelopm ent in a

1.9L D I D iesel Op tical Engine [A ].SA E Paper 950850.

[6]　Kao ru Ho ric ,et a l .T he D evelopm ent of a H igh Fuel Econom y and

H igh Perfo r m ance Four 2valve L ean Burn Engine [A ].SA E Paper 920455.

[7]　Kuw ahara K ,W atanebe T .Op ti m izati on of In 2cylinder F low and

M ixing fo r a Center 2spark Four 2valve Engine Emp loying the Con 2cep t Barrel 2stratificaiton [A ].SA E Paper 940986.

[8]　Stokes J ,et a l ,I mp roving the NO x Fuel Econom y T rade 2off fo r

Gaso line Engine w ith the CCV S Com busti on System [A ].SA E Paper 940482.

[9]　Barber E ,M alin J ,M ik ita J .E li m inati on of Com busti on Knock

[J ].J of F rank lin Institute ,1946:241.

[10]　Kum e T .et a l .Com busti on Contro l T echno logies fo r D irect In 2

jecti on S I Engine [A ].SA E Paper 960600.

[11]　A ndo H irom itsu .Com busti on Contro l T echno logies fo r Gaso line

Engines [A ].P roc A SPA CC ,1977.

[12]　Kazuto N om a ,et a l .Op ti m ized Gaso line D irect Injecti on Engine

fo r the European M arket [A ].SA E Paper 980150.

[13]　M undo rff F ,Carstensen H .D irect Injecti on D evelopm ent T rends

fo r Gaso line and D iesel Engines [R ],AVL L ist Gm bH .

[14]　R yan T W ,et a l .Homogeneous Charge Comp ressi on Igniti on of

D iesel Fuel [A ].SA

E Paper 961160.

[15]　O nish i S .A ctive T her mo 2A tmo sphere Com busti on (A TA C )—A

N ew Com busti on P rocess fo r I C Engines [A ].SA E Paper 790501.

[16]　N oguch i M ,et a l .A Study on Gaso line Engine Com busti on by

O bservati on of Inter m ediate R eactive P roducts D uring Com bus 2ti on [A ].SA E Paper 790840.

[17]　N ajt P M ,Fo ster D avid E .Comp ressi on 2Ignited Homogeneous

Charge Com busti on [A ].SA E Paper 830264.

[18]　Iida N .Com busti on A nalysis ofM ethod 2Fueled A ctive T heremo 2

A tmo sphere Com busti on (A TA C )Engine using a Spectro scop ic O bservati on [A ].SA E Paper 940684.[19]　T h ring R M .

Homogeneous Charge Comp ressi on Igniti on

(HCC I )Engines [A ].SA E Paper 892068.

[20]　Stock ingerM ,et a l .V ersuche an einen gem ischan sugenden V er 2

brennungs mo to r m it Selbstziindung [J ].M T Z ,M o tertechnisches Zeitsch rift ,1992,53.

[21]　A oyam a T ,et a l .A n Experi m ental Study on P rem ixed 2Charged

Comp ressi on Igniti on Gaso line Engine [A ].SA E Paper 960081.

[22]　Ch ristenson M ,et a l .Homogeneous Charge Comp ressi on Igniti on

(HCC I )U sing Iso 2octane ,E thano l and N atural Gas -A Com 2parison w ith Spark Igniti on Operati on [A ].SA E Paper 972876.[23]　Ch ristenson M ,et a l .Supercharged Homogeneous Charge Com 2

p ressi on Igniti on [A ].SA E Paper 980787.

[24]　Suzuk i H ,et a l .Exhaust Purificati on of D iesel Engines by Homo 2

geneous Charge w ith Comp ressi on Igniti on Part [A ].SA E Pa 2per 970313.

[25]

H eywood John B .Internal Com busti on Engine Fundam entals [M ].N ew Yo rk :M c Graw 2H ill ,1989.

沉痛悼念史绍熙主编逝世

这里发表的是我刊主编史绍熙院士生前投到编辑部的最后一篇论文。史绍熙先生因病医治无效于2000年9月16日逝世,享年85岁。

史绍熙教授和燃烧科学领域的专家学者经多年努力,创办了《燃烧科学与技术》期刊。创刊以来,史先生对编辑部的日常管理、财务状况到稿件的质量把关等诸多细节给予了充分的关心与帮助,即使在病中仍多次询问编辑部的工作情况,使本刊在创刊第2年即被美国E I 及CA 等国内外著名检索机构收录,为我国燃烧科学与技术的学术交流与发展做出了巨大贡献。 本期谨隆重刊登此文表示我们的沉痛哀悼。

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51?2001年2月 史绍熙:汽车发动机燃烧技术的新进展

汽车发动机电子控制系统开发现状及趋势

汽车发动机电子控制系统开发现状及趋势 丁志盛叶挺宁 摘要：介绍了汽车发动机电子控制系统相关技术背景、开发现状及发展趋势。 关键词：EECS,ECU汽车发动机电喷 一、汽车发动机电子控制系统概述 汽车发动机电子控制系统(Engine Electronic Control System，简称EECS)通过电子控制手段对发动机点火、喷油、空气与燃油的比率、排放废气等进行优化控制，使发动机工作在最佳工况，达到提高性能、安全、节能、降低废气排放的目的。汽车发动机电子控制系统主要包括： - 燃油喷射控制； - 点火系统控制； - 怠速控制； - 尾气排放控制； - 进气控制； - 增压控制； - 失效保护； - 后备系统； - 诊断系统等功能。 另外，随着网络、集成控制技术的广泛应用，作为汽车控制主要单元的EMS系统通过 CAN(Controllers Area Network)总线与其他控制系统，例如：安全系统(如ABS、牵引力电子稳定装置ESP (Electronic Stability Program))、底盘系统（如主动悬挂ABC(Active Body Control)）、巡航控制系统（Speed Control System或Cruse Control System）以及空调、防盗、音响等系统实现网络互联，实现信息共享并实施集成优化统一控制。在不久的将来，车载通讯平台将利用现有无线通讯网络为汽车驾驶提供更广泛的咨询、娱乐等增值服务（如GPS全球定位系统的应用）。 汽车发动机电子控制系统的开发主要涉及以下技术容： - 传感器 主要包括空气流量传感器、空气温度传感器、节气门位置传感器、冷却液温度传感器、转速传感

汽车发动机技术汇总DOC

你真正懂车么？汽车发动机技术汇总 目前应用于汽车的发动机主要有直列发动机，V型发动机、W型发动机、转子发动机几种 类型。为了使读者对各种发动机有一个更加深入的了解，我们在这里将常见的汽车汽油发动 机类型与各种先进的汽油发动机技术特点归纳在一起，供大家分享。 直列发动机（Line Engine） 直列发动机（Line Engine）：它的所有汽缸均肩并肩排成一个平面，它的缸体和曲轴 结构简单，而且使用一个汽缸盖，制造成本较低，稳定性高，低速扭矩特性好，燃料消耗少，尺寸紧凑，应用比较广泛。其缺点是功率较低。“直列”可用L代表，后面加上汽缸数就是 发动机代号，现代汽车上主要有L3、L4、L5、L6型发动机。 L3（直列3缸发动机）：一般用在1升以下的微型车上。它结构简单，维修方便，制 造成本也低，重量轻，比较省油。如果一台直列3台机能达到一台直列4缸机的动力性能，那当然是3缸机要好些。如早期的夏利车装配的就是3缸发动机。 L4（直列4缸发动机）：直列4缸发动机俨然已成了现代汽车的一种标准选择。它的 适用范围极广，小到微型车，大到2升多的车型，均由四汽缸机为汽车提供动力。与6缸机相比，4缸机的体积小，结构简单，重量轻，但它的动力性和平稳性与同排量6缸机的差别并不十分显著；现代轿车大多为前置发动机前轮驱动方式，需要发动机横放在车头，要求发动机的体积不能太大，直列4缸机的体积尺寸正好，因而直列4缸机获得了广泛应用。 L5（直列5缸发动机）：由于直列5缸机存在很难解决的平衡问题，容易引起振动，因此直列5缸发动机现已不多见。我国长春一汽曾生产过的奥迪100也是用直5发动机。现在沃尔沃S60、S80还在用直5发动机。 L6（直列6缸发动机）：直列6缸发动机现在主要用在前置发动机后驱方式的汽车上。 从平衡角度来讲，直6比直4、直5，甚至V6的平衡性都要好。出于此原因，当你的机

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汽车发动机点火系统原理及故障分析

河南职业技术学院 毕业设计（论文） 题目汽车发动机点火系统原理及故障分析 系（分院）汽车工程系 学生姓名彭超 学号07183160 专业名称汽车电子技术 指导教师王贤高 2010 年 3 月20 日

河南职业技术学院汽车工程系（分院）毕业设计（论文）任务书

毕业设计（论文）指导教师评阅意见表

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发动机-点火系统工作原理

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汽车发动机的发展史

汽车发动机的发展史发动机，汽车中最重要的部分，可以说没有发动机的存在，就不存在汽车。发动机的发展即是汽车的发展。 发动机作为汽车的心脏，为汽车的行走提供动力和汽车的动力性、经济性、环保性。简单讲发动机就是一个能量转换机构，即将汽油(柴油)的热能，通过在密封气缸内燃烧气体膨胀时，推动活塞做功，转变为机械能，这是发动机最基本原理。发动机所有结构都是为能量转换服务的，虽然发动机伴随着汽车走过了100多年的历史，无论是在设计上、制造上、工艺上还是在性能上、控制上都有很大的提高，其基本原理仍然未变，这是一个富于创造的时代，那些发动机设计者们，不断地将最新科技与发动机融为一体，把发动机变成一个复杂的机电一体化产品，使发动机性能达到近乎完善的程度，各世界著名汽车厂商也将发动机的性能作为竞争亮点。 所以可以说发动机的发展史即是汽车的发展史。 而发动机的发展也经历了无数人的努力，无数人的智慧与汗水。 发动机是汽车的动力源。汽车发动机大多是热能动力装置，简称热力机。热力机是借助工质的状态变化将燃料燃烧产生的热能转变为机械能。 往复活塞式四冲程汽油机是德国人奥托在大气压力式发动机基础上，于1876 年发明并投入使用的。由于采用了进气、压缩、做功和排气四个冲程，发动机的热效率从大气压力式发动机的11%提高到14%，而发动机的质量却降低了70%。 1892 年德国工程师狄塞尔发明了压燃式发动机(即柴油机)，实现了内燃机历史上的第二次重大突破。由于采用高压缩比和膨胀比，热效率比当时其他发动机又提高了1 倍。1956年，德国人汪克尔发明了转子式发动机，使发动机转速有较大幅度的提高。1964年，德国NSU公司首次将转子式发动机安装在轿车上。 1926 年，瑞士人布希提出了废气涡轮增压理论，利用发动机排出的废气能量来驱动压气机，给发动机增压。50 年代后，废气涡轮增压技术开始在车用内燃机上逐渐得到应用，使发动机性能有很大提高，成为内燃机发展史上的第三次重大突破。 1967 年德国博世公司首次推出由电子计算机控制的汽油喷射系统，开创了电控技术在汽车发动机上应用的历史。经过30年的发展，以电子计算机为核心的发动机管理系统(Engine Management System，EMS)已逐渐成为汽车、特别是轿车发动机上的标准配置。由于电控技术的应用，发动机的污染物排放、噪声和燃油消耗大幅度地降低，改善了动力性能，成为内燃机发展史上第四次重大突破。 1971年，第一台热气发动机——斯特林机的公共汽车已开始运行。1972年，日本本田技研工业在市场售出装有复合涡流控制燃烧的发动机的西维克牌轿车，打响了稀薄气体燃烧发动机的第一炮。这种发动机是在普通发动机燃烧室的顶部加上一个槌状体的副燃烧室，先将这处副燃烧室中较浓

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发动机点火系统 一、概述 发动机点火方式有炽热点火、压缩着火和电火花点火三种，柴油机用压缩着火，汽油机一般采用电火花点火。 1、对点火系统的要求 点火系统应在发动机各种工况和使用条件下，保证可靠而准确的点火。为此，点火装置应满足下列三个基本要求 1．能产生足以击穿火花塞电极间隙的高压电 实践证明，汽车发动机在满负荷低速时需8~10kV的高压，启动时则常需9~17kV的高压，正常点火一般在15kV以上，为了保证点火可靠，考虑各种不同因素的影响，点火高电压必须有一定的储量，所以点火装置产生的电压一般在15~20kV之间，而且高电压的升值要快。 2．火花塞应具有足够的能量 要使混合气可靠点燃，火花塞产生的火花应具有一定的能量，发动机正常工作时，由于混合气压缩终了的温度已接近其自燃温度，因此所需的火花能量很小（1~5MJ）。蓄电池点火系统能发出15~50 MJ的火花能量，足以点燃混合气。但在发动机启动、怠速运转以及节气门急剧打开时，则需较高的火花能量。 启动时，由于混合气雾化不良，废气稀释严重，电极温度低，故所需的点火能量最高。另外，为了提高发动机的经济性，当采用空燃比α=1.2~1.25的稀混合气时，由于稀混合气难于点燃，也需增加火花能量。考虑上述情况，为了保证可靠点火，火花塞一般应保证有50~80MJ 的点火能量，启动时应产生大于100MJ的火花能量。 3．点火时刻应适应发动机的工作情况 因为混合气在发动机的气缸内从开始点火到完全燃烧需要一定的时间（千分之几秒），所以要使发动机产生最大的功率，就不能在压缩行程终了活塞行至上止点才点火，而是需要适当提前一些。 因为发动机气缸的多少，负荷的大小，转速的变化，燃油品质的不同，即是同一发动机由于工况和使用条件的不同等等，都直接影响气缸内混合气的点火时间，为了使发动机能发出最大工功率，点火装置必需适应上述情况的变化实现最佳点火。 2、点火系统的分类 按照点火系统的组成和产生高压的方式不同，发动机的点火系统分为：传统点火系统、半导体点火系统、微机控制点火系统以及磁电机点火系统。 1）．传统点火系统 2）．半导体点火系统 3）．微机控制点火系统 4）．磁电机点火系统 二、传统点火系统组成与工作原理 1、传统点火系统的组成 传统点火系统主要由电源、点火开关、点火线圈、配电器、火花塞等组成，如图9-3所示。 （1）电源电源为蓄电池和发电机，供给点火系统所需电能，标称电压一般是12V。 （2）点火开关点火开关的作用是接通或断开点火系统初级电路。 （3）点火线圈点火线圈即变压器，其功用是将蓄电池12V的低压电变为15~20kV的高压电。 （4）配电器配电器的功用是接通和切断低压电路，使点火线圈及时产生高压电，按发动机各气缸的点火顺序送至火花塞；同时可调整点火时间。

发动机管理系统

发动机管理系统 Company Name 公司名 排名 研发中心 工厂 Bosch 博世 1 苏州 联合电子（上海、西安和无锡）、无锡博世威孚（柴油） Delphi 德尔福 2 上海 北京德尔福发动机、北京德尔福万源 Continental 大陆汽车 3 上海 原SiemensVDO 的芜湖、长春工厂；原Freescale 的天津工厂Magnetti Marelli 马瑞利 4 芜湖工厂、上海工厂 Visteon 伟世通 5 上海 重庆工厂 Hitachi 日立 6 Denso 电装 7 仅供Toyota Valeo 法雷奥 8 Eontronic 意昂神州 美国 北京总部、上海分部 TroiTec 锐意泰克 Vagon 华夏龙晖 阳光泰克 Woodward 伍得沃德 成都汪氏威特电喷 成都易控高科 中联汽车电子 无锡油泵油嘴研究所 美国MotoTron 公司是Woodward 公司的子公司，主要从事发动机电控 系统的开发与生产。该公司针对汽油发动机设计了一套完整的控制策略 快速开发平台，此平台从设计开发到生产贯穿一体，可有效地缩短开发 时间，加速产品化进程，降低开发费用。 美国精确技术公司(Accurate Technologies Inc)是车载嵌入式电控系统 ECU 开发、标定与测试工具技术的知名提供商。该公司的ECU 标定系统 (VISION)功能强大，好学易用，而且和Matlab/Simulink 开发平台无缝连接， 多年来被福特(Ford)汽车公司、德尔福公司(Delphi)、沃尔沃卡车公司等指 定为标准匹配标定系统。该公司的No-Hooks 软件是ECU 控制策略快速开 发领域的重大突破。用户只用标定文件(*.a2l 与*.hex 文件)，而不需要控制 策略源代码即可对控制逻辑进行修改。修改过的代码自动灌装进原来的 ECU 内进行测试运行。该技术已在美国、欧洲与日本得到了广泛的应用。 美国RMS(Rinehart Motion System)是一家专门从事功率驱动产品与方案 的公司。该公司提供或定制5-500KW 级应用于混动或纯电动控制系统、能 源贮藏系统和大功率设备的电机驱动器、静变流器、DC/DC, DC/AC, AC/DC 等产品。现有客户主要为军工、汽车或跑车、农业机械、工业控制 等行业的世界知名制造公司或主机厂。RMS 与意昂科技将为国内客户提供 产品技术、项目咨询、定制开发等服务。 美国Drivven, Inc, 公司自2003年起提供汽车控制和数据采集解决方案， 已经成为发动机和车辆电子系统开发新标准的领导者之一。基于FPGA 汽

未来汽车发动机系统的技术展望

未来汽车发动机 系统的技术展望
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内燃机所面临的挑战和危机
? 对油耗和排放越来越严格的法规标准 ? 来自电动汽车和只排水蒸汽的燃料电池 汽车的威胁
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内燃机进一步改进所遇到的 三大主要难题
? 希薄燃烧的排气处理技术
– NOx – PM
? 直喷汽油机的燃烧系统和排气处理
– 低负荷轴效率 – NOx (LNT)
? 均匀混合压燃式发动机(HCCI)的控制技术
– 工作范围的扩大 – 瞬态工况变化的控制
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未来柴油机和汽油机的比例
? 汽油机仍然占主导，80％以上 ? 柴油机在西欧的比例将持续增长
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柴油机和汽油机的比较
－价格
6缸100千瓦汽油机价格分析表
柴油机的价格贵30~50%左右
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汽车发动机发展史

汽车发动机发展史 汽车整体技术日新月异，而作为汽车的心脏——发动机技术的进步显得更受关注。如今介绍一辆汽车的发动机时：可变气门正时技术，双顶置凸轮轴技术，缸内直喷技术，VCM汽缸管理技术，涡轮增压技术，等等都已经运用的相当广泛；在用料上也是往轻量化的方向发展：全铝发动机目前的应用已经非常广泛；汽车的污染也是不可避免，于是新能源技术，包括柴油机的高压共轨，燃料电池，混合动力，纯电动，生物燃料技术也已经有普及的趋向，但回顾一下发动机的历史或许更能理解这一百多年来汽车技术所发生的巨大变革。 十佳发动机VQ35 汽车技术的迅猛发展从我国的汽车教材也能看出端倪：新技术的发展已经让汽车教材难以跟上步伐！如今大部分汽车教材还是以东风汽车的发动机来作为范例，而东风发动机还是带化油器的老式发动机，与如今全电子化的发动机简直就隔了几个世纪。 回到汽车的起步阶段，那时的汽车被马车嘲笑，污染严重，但起步的意义却非同寻常。 汽油机之前的摸索阶段

18世纪中叶，瓦特发明了蒸气机，此后人们开始设想把蒸汽机装到车子上载人。法国的居纽（N.J.Cugnot）是第一个将蒸汽机装到车子上的人。1770年，居纽制作了一辆三轮蒸汽机车。这辆车全长7.23米，时速为3.5公里,是世界上第一辆蒸汽机车。1771年古诺改进了蒸汽汽车，时速可达9.5千米，牵引4-5吨的货物。 蒸汽机汽车 1858年，定居在法国巴黎的里诺发明了煤气发动机，并于1860年申请了专利。发动机用煤气和空气的混合气体取代往复式蒸汽机的蒸汽，使用电池和感应线圈产生电火花，用电火花将混合气点燃爆发。这种发动机有气缸、活塞、连杆、飞轮等。煤气机是内燃机的初级产品，因为煤气发动机的压缩比为零。 N.J.Cugnot 1867年，德国人奥托（Nicolaus August Otto）受里诺研制煤气发动机的启发，对煤气发动机进行了大量的研究，制作了一台卧式气压煤气发动机，后经过改进，于1878年在法国举办的国际展览会上展出了他制作的样品。由于该发动机工作效率高，引起了参观者极大的兴趣。在长期的研究过程中，奥托提出了内燃机的四冲程理论，为内燃机的发明奠定了理论基础。德国人奥姆勒和卡尔·本茨根据奥托发动机的原理，各自研制出具有现代意义的汽油发动机，为汽车的发展铺平了道路。 1892年，德国工程师狄塞尔根据定压热功循环原理，研制出压燃式柴油机，并取得了制造这种发动机的专利权。

汽车发动机管理系统检修

第8 次课模块一发动机管理系统的检修 项目1.8 发动机管理系统的仪器诊断? 目的要求掌握使用故障检测仪对发动机管理系统进行检测与诊断。 ? 教学重点使用故障检测仪对发动机管理系统进行检测与诊断。 ? 学习难点 使用故障检测仪对发动机管理系统进行检测与诊断。 ? 教具及工具 桑塔纳轿车 2辆，各种传感器若干，通用工具 2 套，万用表 2 块，汽车诊断仪 2 台。 ? 教学内容及时间安排（ 180分钟） 1. 问题的引入约 10 分钟 2．汽车电控系统诊断方法约 40 分钟 3．使用 1552 对上海大众桑塔纳 2000 型轿车进行检测与诊断 约 130 分钟

教学内容组织与过程设计备注

课程引入（约10分钟） 汽车电控系统诊断方法（约40分钟） 一、汽车故障诊断新技术 2.3.1案例法 传统的故障诊断中大部分是（，基于规则推理）、（，模式推理）的专家系统技术的研究。由于这些传统的专家系统是基于模型化驱动的（基于模型的诊断方法使用诊断对象的结构、行为和功能模型等深知识进行诊断推理），在模型的构建、信息的获取、信息的处理方面存在严重不足，有一些难以克服的缺点，如系统领域知识的规则提取困难；规则库、模式库的创建和管理复杂艰巨；推理过程中规则与模式难以准确选取等。 整个汽车故障诊断系统主要由知识库、故障案例库、征兆数据库和推理系统构成。其中主要部分的内容和功能描述如下： a）知识库。问题求解的知识、经验的集合，主要由专家提供，包括

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