P1991-10-2
EUROPORT DIESEL ENGINE
SYMPOSIUM '91
14th and 15th November 1991
p A fi r r 0
Europwt Diesel Engine Symposium '91 MOTOR 2000 plus
is jointly organized by:
VIV - Association of Combustion Engine Inqxirlm
GVM -Gioiq) of Manufacturers of Combustion E
Al\4STERDAM rai T W . RAI - Intematicmal Exhibition Centre
MARINE BUNKER FUELS • TOWARDS 2000 J P Uddy, Tectmicâl Manager - Fuds
1. INTRODUCTION
In die discussion of trends in bimki^ fud quality winch SDUOWS, it is w<»th remraibaing two feattnes of liesidual fiiei oâ pioductiöa and use. The fiist is that the lefîner does not set out q)eâfîcaùy to manuâctuië bunker fiiel; rather, sudi fiid is a l^-inödüct of a refining process mainly geared to production of die distillate trm^xirt ftiels. This feature is r e f l e t in the rdativdy low inice of bunkra-fîid (idative, that is, to die distillate fîids, and indeed to die crude from whidi it is produced). The second fieatuie to note is tint resdud fud of die type conamon in today's ma^ssx rnay not be the ideal füd for a marine diesd engine; die reason why such £ad b widdy used is, of course, its rdativdy low price. There is dien an inherent conflict between price and quaMty of bunker fiid. A survey carried out in
1990 by Lloyds List in coiijunction \ndi Traoa^ Oil neatly iUustratied Ms. lite survey sought to estaüish what buyers peicdved to be impcrtant whoi {wirchasing bunk^ fiiels. Whea buyers were asked how sui^liers could inqnxive didr sovioe, "better quality" of fud was i^ntified as the tt^ prumty by a large m^piity. Hpwever when buyers wm asked what thdr over-ridmg cpnadoation was wl»n actually buying bunkers, die issue of price beat that of qualüy to die top position.
Price and quality will continue to exert thdr conflicting pressures in futùtr^ however there is an additiimal factor which could havé an raormous influence ästet the nature of die bunlœr market in die coming decade. That £actor is legislatra to contrd air polMôa from shipping, this paper wiÙ examine how changes in refining prance have affected fiid quality in rec^ years, and will address the role of spedfications in contiolHng fiid quality. The potoitid d&cts of environmentally driven l^islation on the fubms avaOabiHty ami price of bunko* fiiels will then be ûscussed in some detail.
2. REFINING liÈCHNOIX>GY AND FUEl QUÀUTY TRENDS
There has been no shortage of papers published in recent years documenting die changes in fiid quality due to die introduction of what are turned se^ndary Cpnvo^lpn processes in refineries, these processes are iioter^ed to satisfy changmg demand pemems, namdy an increasing demand for distUlate transport füds condnned with a decreasing demand for fiid <nl. Thdr intiôducti<m has led to a change in fiid quality fiom that whidi prevailed when refinerieis were, in the inain, pfrodiidng ^raightHTun products. The significant dianges in fud properties are: an increase in density, an moease m carbon rendue, and an increase in natural metals contait (sndi as vaôulium), and possibly the sqypearance of catdyst f i ^ The oonclusikm readied by some of the published papiers on the safajeet is that these trends will continue remOTsdessiy http the fiiture.
Some available data does not bear this out however. A psçer presented by Veritas Petroleum Services to the 1989 Norw^um Bünte Gmferenoe gave daû on the average values of certain fud quafity parameters over die period 1981 to 1988, for fiids in die 250-400 cSt viscosity band. Hie parameters density and caifoon rendue give a good guide to die extent to which products of secondary converâon procoses are incorporated into the bunker fud oil pod. Trends for these two paramden are presented in F^;ure L U can be seen diat density has risen slightiy over die period, but zppem to have reached a plateau; and carbon readiie reuhed a peak in 1986, and has since fkllen sifigfady, Furdiermore, die average vdues of diese two paramders fall wdl ^thih current qiedficatipn maximau It dius zppsim dût we have not sees repeaüy any great increase in die amount 0f products fiom secondary oonverapn processes in the bunker fiid oil pod. Hierê are two likely reasons for diis; the first is diat there has been littie need or <yporhinily for investment in secondary conversion processes in nsfineries in recent years; the oth^ is diat some refiners have recentiy diosen to invest in die new g/ssiiatàm of rendue upgiaifing processies, whidi produce mudi smaller amounts of fiid dl than die older secondary pETQcesses, <»: (in the case of cpldng) produce no resîdud fud at all.
dns trend onpûnue in die future? As noted m die introduction, the dominant factpr ad&ctiiig tfae sorts of processes the lefiher will adopt in the coming decade, and hence affecting fiid quality, is Ukdy to be legislation designed to control air pdluti(m fioih shipinng. Exüictly lu>w this afGects fîœl quality, availability and price, will d^end very mudi on the form fiiture l^islati<m takes. This imputant issœ is discussed in detail in serions 4 to 8 of diis p^er.
3. SFECinCATIONS AND FUEL QUALHY
While quafity paramders such as d^ty and carbon residue depoid strongly on die type of processes bdng used by die refiner, odier parameters are more a reflection of the extent and success of die quality ccHitiol ptooeduces en^plpyied in manufiu^turing, blendng, and distributing fiids. Induded in diis calory are parameters sach as Qdalyst fines content (as measured by the duminium and auicon content), and the stability of die fiid (measured as the Total Sediment by filtratkm). Data pdiiished by V^tas Petroleam Services in die joumd "Marine Pn^mlsion' in August 19S8 of&rs a view of the trends in die frequency with which fbds exceed certain ^ledfication maxima; some of this data is rqnoduoed in Figure 2. The frequency of quafity exertions does not ^^>ear to have încrîeâsed sigrlificändy over the period; in fact for catdyst fines the fiequdocy of exiGiq)tions a^ypears to havé declified. Ihereareanuntoof &ct(»s whidi are fikdy to have pk^ed a part in dtis stabilisation of quafity: greater awamiess of fuel quality issues by b(Hh fiid users and fud »ippfira; the increasing uptake of the s^ces offered tp shipownm by die various find testing services; arid die publication and hicreasing recognition of the mternationd fud standards ISO 8217 and die BS MA 100.
It is wordi ntfûng in passing diat, widi the revision of BS MA 100 in 1989, this standaid became identicd to ISO 8217. Aldiough in the cunent version of diese sUUKlards the controls oo duminium (and dius on catdyst fines) and on Tptd Sediment (and dms fiid stability) ^pear ody in an Annexe to die stauidard, stq» are
vaàèiwây within die Intemationd Standardiiation Organization to revise ISO 8217 sod ihocnporate diese ccmtrols in the maui body pf die qiecificatipn. The next
revidon of ISO 8217 is fikdy to cpntrd catalyst fines by a limit on aluimnium jdus sifioon of 80 mg/\:%. For a catalyst of "average" coinpoâticm, dus represents a no-change dbfidion compared to the limit of 30 mg/^g on diumnium akme given in the Annexe to the current standard. However it doeis offer a bett^ way of controlling catalyst ocmtent in cases where catdyst oon^wsition diffm from the avmge. Fud stabifity wfil be controlled by a limit on die Totd Sediment measured the hpt fütratïonmethod IP 375, ami it wiU be stipulated that sedunent wiU be measured after ageli^ the sanqde for 24 hours at lOO'^C; this ageing is deâgned tp ensure diat fiids
supplied have an adequate stabifity reserve.
The on&xtal version of the British and ISO standards, and dîdr subséquent reviskHis, were arrived at by a process of cotisensus betwedi fiid suppliers, end users, and equqmi^t manufacttirers; diey were devdcqiéd för an immediate practicd opeiadond reason of direct intrest to the parties involved, namely to oisure that the qudity of die fiid was suitable feu: Use in die intended equipinent, without imposhg unnecessary restrictions which might unddy affect avaiïainfity and hence pricei. We are now seeing the emergence of new restrktions pn fud quafity, wfaidi are being shaped to a Eaige exteat by thpse not immediatdy involved as suppliers or consumers of marine fiids. These restrictions, which are intended to botefit a wider comihuöity, are those concemed with controUing the^trat of air poUutaiit énussocms from shipfmig; their inqileihenitation codd have extremdy significant effects on availabifity and price of biihker fiiels in the fiituré.
4. SBOiPFING AND AIR POLLUTION
The attCHticm b^ng .paid tp die role of shipping in air poUution has already led to some locd restrictions, often voluntaiy, on fiiel quafity. Examples are the use of Ipwrsu^ur fiiels by ferries in Scan<finavian and Bdtic watérs, and m tanker movements in the Prince WUfiam souiid in Alaska. Taxation incentives to caocourage use of low-sulphUr fiids are also bdng used, for ecample in Scandinavia. Regiond controls are sho und^ con^ration; die Commission of the European Community is now activdy oonàdering a pacfeige of meanires to oontrd SOt poissions fîrpm the petroleoin rdimhg cham, and this package includes restrictions cm the sdphur content of bunker fiid oils, marine diesd dis and gas dl. The maximum sidfriiur levels qiedfied in the pn^posd before the Commission are 2 per cent for bunker fiid dl, 0.5 per cent for blended niarihe diesd dl, and 0.2 per cent for marine gas dL
iknvever bec»ise of the intemationd nature of ^ppiDS! operations, ^ective oontrd of emissions or of fiid quafity without distorting oomp^tivoiess is likdy to be adiieved ody through intrariatipnal regulations, endorsed by an audiorit^ive int^nationd mganisation. Thus for Ae last few yeara, die issue ot air poUutkm from
shippmg has been on die agenda of die Intemationd Maritime Oigamzation (IMO). 5. THE ROLE OF IMG
IMO is a United Nations agency whidi deals widi techmcd suspects of ship{nng. Aldioagh IMO's pnamy task is to pnmiote shqiinng safety by introdudng intemationaUy accepted standards, die prevention of pdhitkm from sh^ng has evdved as an »kfitiond task. The delegates to IMO are representatives of dhe governments of the member slates, tc^edier widi a limrted nimiber of observers from recognued ihteraatiood organisations. IMO is formulated within its committees; the one deafing ^di die air pcdhition issue is die Marine Envîromnent Protection Cotnmittee (MEPQ. Tbe MEPC in turn, having devdoped outline pofides, then passes dMsse over to a rdevant sub-oomimttee to develop die tedmicd ddaOs. In the air poUution case, die leaifihg sdhooônnûttee is the Bulk Chemicals sdi-cpmmittee.
A recent outcome of the délibérations of IMO-MEPC has been a draft resolution whidi is to be sdimitted to die Goierd Assrad>ly pf IMO, calfing fbr (amongst odier réstricticms) reductions in emissions of SQi and NOx frotn shipping. Mudi work remains to be done within IMO on ftialiang reduction targets and in devdoinng detailed plans for how the desired reductions wiU be achieved; however discussions widün MEPC have revolved around target reductions of 50 per cent Î<K SOZ odssaons and 30 per cent for ermssions of NOx, both to be achieved by the year
Of these two pdlutant spedes, die SO, emisaons are a dired fimotioi of die sulphur content of bunker fbd, while NOx odsdpns, formed predominandy froih oxidation of nitrpgen in the cpmbusticm air, éepeaé on engine type and qieraitiiig oonditiCTis. In die case of NOx emissipns, die target reduction levd wtddi has been discussed at IMO-MEPC is 30 per cent. The measures whidi aré gdiaraUy proposed to achieve reductions pf düs magnitiKte are modifications to die combustion cyde of the engme (whidi wUl incur a pendty in fiid coiisuniptiQn); and use of watra- mulâfied in the fud (which hi ihany, cases wiÙ require some modification to the en^ne, and again wiU generaUy incàôr a fud consumption pendty). A ddrd (q)tion is tp instafi exhsuist gas deaning plant Such plant is gen^aUy based on a Setective Catdytic Reduction (SCR) imcess, in which ammpnia iigeded into die exhaust gas reacts with the NOx over a catalyst bed to produce mtrogen and water. For reducticms in NOx of iq> to 30 per cent, use of such an exhaust gas deaning plant wiU genraUy be a more expensive itolutiräi, compared to the first two methods mentioned; hpwever the SCR process is callable of giving much higher levds of NOx reduction, up to about 90 per cent
The remdnder of this paper vnU concentrate on the usue of greatest significance to the dl refiner, namdy contrpl of SO^ eimssions. It is importent to note in pasdng that ddiougb this papa is concentrating on combüstion-génerated poUutants, the MEPC iHoposals are much wnler dian this, and seek to impose contrds on odier tnajsters of sigmficanoe to ship builders, owners, and operators. Tbese additicmd fopton indude cisntrds on die use of HAlons (used ia fire fighting systems), on use of ddoxofluorocatfoons (CFCs, used in refrigeiatipn smd air-conditioning), on die poformance of indnoators used for diqx>sd of ^p-genenited waste, and on dte einisstons of vdatile organic pmnpouids from operations such äs oil cargo transfers, träokering operations, and gas-freeang of tadis.
6. CONTROL OF SULPHUR DIOXIDE EMSStONS
Tfaere are basicaUy two Options for cootrdfing SQi emissions: dtha £be SO3 can be removed from a ship's eaÂaust gas, or its fprmatipn can be fimited by restricting die sdphur content of the fiid. Sdpfaur dSpx^ may be removed from combustion exhaiust gases by seawater scrobbing, a technique which has been zppikd for many years in some land-based power stations, and is u ^ to dean iq> dte gas in inert-gas gaioatpra at sea. The sdtabifity and practicafi^ of die techmque for cleaning e:diaustgaaes from ships is ody now bdng eval^^ An exhaust gas cleaning plant, designed to remove both SO, and NOx, faias been mstalled cm a ferry operating between Norway and (jénnany; tfais work, is bdi$ suiqxirted by die feny operatpr Color Line, the Norwegian omsdtancy firm a/s MUjontvpdingv and Norske SheU. Resdts presented at a recent conference incficde that h ^ reductions of SO2 emissions can be addeved, though fiirther evduation remains to be done. The MEPC has yet to pnxiounce tipoii ^ enviitmmentd accq;>tabifity of this sdiition; sonte of the dd^ates to MËPC have expressed concern dx>ut the envirooimentd and ecdpgicd effects of die discharged wash-water from the deaning plant This a^[>ect is of course being addressed as part of the jomt programme referred to above.
Thé altemative to SQi rmovd from etfaaust gas is to lindt the siJ^hur content of tmnker fiid. At present, the average sdphur coiitent of bunker fiiels wcnrldwide is dxHit 2.8 per cent If a reduction in total SO2 emiissipns of 50 per cent (die figuré bdng considered by IMO-MEPQ were to be achieved by controUing fiid quafity, thai the average budoer fiid su^ur would have to be lowered to 1.4 per cent To addeve an average «di^ur levd of 1.4 per cent probddy ineans in practice sdtitig a maximum fiidt ody sfighdy higher than this, since in the supply-constrdned situation that would resdt from such a restriction there are imfikdy to be many
bunk» suppfifô whidi have sdphjmr levds Hie fimit which has heea proposed in (fiscussions at MEPC is 1.5 per cént There sue
two ways in which fuels meeting such a restriction ön maxîrmiin sulphur content codd be produced: by desdphurisation Pf high-sdi^ur residues, or by produdng bunker fiteb predonnnandy from crude dis which are naturdly tow in sdphur.
7. LOW SULPHUR BUNKi» FUELS - D4FLICATIONS FOR THE REflNrâ Residue desulphurisation (RDS) is friirly weÙ established tecfandogy. The RDS process invdves treating fiid at high temperatures and high pressures; these severe process conditions rendt m plant of td^ aqntd cpst The investment required obviously dqiends oa dte capadty of die RÎ^ unit uid on various site-spedfic conaderations, but as an indication the costs for a RDS umt óf20,000 barrels per day capadty have been quoted in various studies m die range of US$15(>-350 mUlion. The additiofid product cost ariang fixmi die RDS pocess depends qdte strongly on tfae decailed asnur^ons made in calculatihg die discounted cash fiow aridng from the mvestment together of oourse undi site-^edfic (iterating costs. Most stidies whidi have been carried out estimate that the cost of towoing Ûie saïphm content of a residue from 3.5 per cent to U po^ cent wodd increase die cost of product by between US$45 and ÜS$84 pn ton. Pofaaps tifaough a mem tignifîçmt fector dte refîner than die additiond product cpst is die questicm of the mitid laig& c^td investment It is by no ineans c^tain diat aU refinm would diose to make dûs sort of mvestment in bunker fud production. The dteroatiVe to RDS for the refiner is investment in some sort of rendue destruction process, which produces more vduable <fiistûlate streams and litde or no fiid dl. To many refiners, investment m residue destruction may a^^teair a more attractive o{don than investhig in RDS, thereby teading to deóeased availabUity of fiid oil.
For production of low-sulphur fiid oil, the dternative to RDS is to produce fiid oU predominandy firom low-sulphur cnide dls^ Current demand for low-sdphur fiid d l (LSFO, here deeped as having less than 1 per cent stu^ur) is presentiy of the order of 110 mUfipa tpns per ^ u m . LSFO generaUy commands a price premium over highTsuli^ur, the price differmtid in the last few years is shown in Figure 3, for the Rotterdam barge maricet The dfierentid has osdUated ra|»dy bdweoi about
ton and $43 per ton, with an av^age of about $15 p^ tern. Hie osdUatipns saggBst tfaat eidsting demiasd (maidy firom inland power generation and mdustrid plant) ^riy dosdy balances siq^y.
The current world totd bunker demand is about 140 liullion tons p^ annüm, and to meet this total dennand widi a fuel having a majomum aili^i^ of 1.5 per cent would effectivdy reqdre about 107 mUlion tons p^ year of LSFO (ie less dian 1 per cent sdphur). If therefore intematiortd legislation compelled shipping to use 1.5 po- cent sd{diur bimker fuds globaUy, the worid demand for LSFO wodd sqiproidmatdy doùble. Cïertaidy such a growth in demand wodd inaease the difiereaatid between LSFO and high-sdphur fiid dl vn the short term, probably to a levd at least as h ^ as tfae peaks seen in the past In Ae medium to long term, a odling to die differentid might effectivdy be provided by the cost of fiue gas desiilphïirisati<m at inland power stations, since at differentials above tfals levd it beocmtes attractive for a ppwer generator to switch from LSFÓ to high-sdphur and inv«t hi fiue gas desdpfaur^atioa ^ABOL the cost of flue-gas desdphurisatipn is again scale- and site -dependent, but indicative costs, cdculated bade tp a cost per Um of fiid basis, are in the range US$25-40 per ton (Xf fiid. Thus die ceUmg cm dte LSFO-HSFO diffi^tid im^died in the medium to long tarn by this ixend wodd be at least $25 per ton, or periia^ muchfaigfa».
8. FUTURE DEVELOPMENT OF INTERNATIONAL REGULATIONS
It can be seen dien diat globd restrictions on birakm fiid sxûçhm codd have very cpnsidetdde effects on bodi price and fiibire avdldnfity of bunker fitels. It is inqiortant dimfore diat before any restrktmns are pu^ die benefits whidi aré ô^iected to fdlow are assessed in rdatkn to the costs, and die irnjplicaHons fbr fiiture siqiplies evduated. The Bdk Chemicals sd>^numtteiB of IMO, whidi as noted d»ove is devdoping future regulationis gpverdng air pdQution from sfaipinng, met in Sep^ber 1991; at diat meetmg, die need to condder dtese fectpn was recognised. Consequently dte sub-committee bas deferred find deddpns on die target levels for SOa reduction, and on v^iedier such reductions wffl be sieved by exhaust gas dean-up or by fiid sdpfaur testiiictipns; however the 5Ó per cent reductiion taiget mentioned above stiU spears to be regarded at least as a desnable göaL These dedsions have been deferred in onder to allow consideration of dte outcome of stud^ cumraidy being carried out by various mdùstry, government and consdtancy grou]^, and which are expected to report during 1992. Induded in these ^udes are two bdng carried out by CONCAWE (the Oil Compames Eurc^iean Organisation for Envinminent and Heafih Protecticm). One stody is exanmnng m detaU the cost and sui^y/demand implications if restriction^ cm sulphi^ leveb are imposed; the cdi^ is assessing the aiyironmoitd unpact pf emissipns from shipping.
Emissions from ^jppmg movements m congested inshore waters and in ports may afreet air quafity and add depodtion on shore, and therefore there codd be etivircmme&tal bcsnefits in reducing such emisaons. However, in dte case of emiisacms from deq>-sea shipping, die atuation is less dear cut There is a view windi says diat die poUutant spedes present m tfae exhaust gas from a äüp wiU be deposited in die sea over a certain distence, and diere wiU be dUuted to inägnifkant levds. If tfaatisdiecase, diere wiUbefitdeornoenvkpnmenMba^
controlling SO2 eimsakHis from deep-sea stupping; dl or most of tfae desired environmentd benefits codd be aefaieved by control of emissions in certain coastd and pott areas pidy. Tbe coUection and andysis of the sdétittfïc evidence to aUow a sensible dedsion to be readied on dûs matter is a major activity of dte second of die CONCAWE stucfies mentioned above.
Tfaeotttcomeof tfae study wdl be importam. Ifit is demonstrated diat there is a vafid case for distinguishing between ^ ^ p n s finom 'sen^tive coastd" shif^g and diose from "deep-sea" shipping (however diose terms may be defined)^ and diat diere is an eivirpnmentd bene^t to be gained from controlling emissions in "sensitive coastd" waters ody, the impUcations for both supply and cost codd be very different tam die case of global controls. In particdar, if ddy the bimker fitel consumed in "sensitivecoastd" waters was reqdred tobe low-sdph^
a nuncff psût of the totd bunk^ demaid, dien tfae d u ^
industry codd be mucfa less.d|rainatK:; as a consequence the overaU costs wodd be lower dian wodd be die case if glpbd réstricticms wére required. Sûdi a two-tier
sppToach is not without its own cpmpfications of courae enfivcement would be more
dfficdt than in tibe case pf a smgle globd restricti<m; and for the ship ppetator dwre wptdd be a need to carry and to keep segregated high-sdphur and loW-sdphur bunker fîids. The cpst of dealing with these coii^licati^ms would need to be we^^
die lower costs on dte supply side for die two-tier sqqmnch; cleariy an inqxfftant fador in any stody of die impfications for bodi fiid supplia and shipowno- will be an ctimate of where the boundaries between "sensitive coiastd" and "deqi-sea" are drawn, whidi will determine die fractieu of totd bunker fud demand subject to die "sensitive coastd" eimssim contrds <a quality restrictions.
Aldtough, as noted dxive, dedsions by IMO on target reductions and how th^ are to be addeved have been deferred teanpprarily, the Bdk Chemicals siib-committee is nonethdess pressing ahead widi drawing up the tegdatOry firamewodc within which controls wiU be implemented once tfae rdevant dfidstons have been made. Parties likdy to be affected by the IMO proposal wodd be wdl advised to fdlow dosety the devdc^ments at IMO, and inject dieâr views mto die debate duough die appropiiate channels.
9. CONCLUSIONS
Data 00 treads in fbd quafity changes attributable to use of secondary codvosion process® suggest that dte rate of change of fud quafity omdl faas slowed <»r leveUed out Fpr dte fiiture, f i ^ quafity and avdlabil^ wiU be affected by dte types of propess tedinolpgy adopted by die dl refiner; this choice in turn is fikdy to be affected by legislatton intoided to contrd air pollution frpm sMj^nng. Tfae fbrm and extent of such legislation is still uider development It is importent that as part of diis devélopment process dte beasts arising from any cotitrols be assessed in a sdentific manner, and evaluated in rdation to costs. It must be borne in mind diat gloibd restricticMis on bunker fiid sdphur omtent codd have an enorindis effect on the future ayailabUity and price of bunker fuds.
Density, kg/I
0.990
0.985 h
0.980 h
0.975 h
0.970
1981 1982 1983 1984 1985 1986 1987 1988
Carbon residue,
percent
14 h
13 h
12
1981 1982 1983 1984 1985 1986 1987 1988
Fig.1 Trends in average density and average carbon
residue woridwide, for fueis In tlie 250-400 est bsatd.
(Source: Veritas Petroleum Services, prsMnted
Parameter
Exception
ilmtt
Water
1.0%
vol.
Ash
0.2 %
mass
Aluminium
34
mg/kg
SHF
0^2 %
mass
2Q1986
2.3
0.1
2.8
2.1
3Q1986
1.4
0.0
2.1
0.3
4Q1986
2.4
0.1
1.6
0.8
IQ 1987
2.0
0.1
0.8
0.9
2Q1987
2.5
0.3
2.0
1.4
3Q 1987
3.3
0.4
1.9
1.0
4Q1987
Z 2
0.0
1.4
0.8
IQ 1988
2.3
0.2
0i8
1.4
Fig.2 iFrequency (In percent) with which quality
paraimters exceed the exception linilts shown.
(Source: Veritas Petroleum Services, published
In iUlarine Propulsion, July/Aug.1988)
Price differential,
$US/metric ton
50 T
40
H
30
A
20 -4
10 H
T - T T T ^ ' Y ^ I I I I I I I I I I I I I I I ' T T T ^ ^ I I J I I I I I I I1988 1989 1990 1991
Fig.3 Price differentiai t)etween iow-suiptiur and
high-sulphur fuel oii. (NWE barges, from
Jan.1988toSept.1991)
Truclc engines in the 21th century,
Technology for Marine Diesel Engines ?
Dr J j . Seppen, D.M. Heaton C Eng.
TNO Road-Vehicles Research Institute Delft. The Nedieriands
Europort Diesel Engine Sympodüm 1991 Motor 20004- 14*^/15^ November 1991
TRUCK ENGfNES IN THE 21th CENTURY, TECHNOLOGY FOR MARINE O I ^ E L ENGINES ?
Dr Ir JJ. Seppen, D.M. Heaton C. Eng.
TNO Road-Vehicles Research IiKtitute Delft, ThjB Nedieiiands
SUMMARY
In diis presentation an overview is given of the technology expected to be applied to new European truck engines in the coming 10 years, and its suitability to application for larger engiiKS is reviewed. Generally tbe chosen technology wiU fulfil the required demands (e.g. emission and performance requirements) against minirnum cost accumulated over lifetime. Trends and reasons for endssion legislation for trucks will be given.
For track engines to reach the requixed demands and still maintain competitive a large number of tiieasures are expected to be taken. To obtain better combustion high injection pressures are needed and the coinbustion chamber suitably matched. Breathing and fuelling has tp be more controlled and efficient. Exhaust gas aftertreatrhent will in some cases be needed (or certainly advantageous) to obtain low HC and particulate ennssibns. Engine management systems will be mtroduced, mmnly because the emission limits can be achieved
Avith more competitive p^omiance.
Apart ftom the engine changes, the sulphur content of Diesel fuel for road use is expected to be reduced, a reduced S content (< O.OS %) is desirable tp attain the particulate limits and also allows the advantageous spp^caäon of an oxidation catalyst
In the I^ge and medium speed marine engine märket, emissions are currentiy only restricted within a limited iiiunber of areas. Whilst it is not expected that songent and widespread legislation is likely to be enforced at short notice, legislation is anticipated in more areas. Thus it can be seen diat the exhaust ermssions are becoming more and more mflUential in the development of such engines. Also with respect to these engines for generating duties, in several areas emissions are already an important item.
For special ^plications and in the longer term some technologies obtamed from research projects and general experience with truck engines, giving more general insight or knowledge can be mteresting ftir larger engines. Perhaps also on the other hand, experiences with larger engines with conq>lex hardware can be interesting for smaller engines to obtain bett^ trade-off between emissions and fuel consumption.
IIS»
-2-1. INTRODUCTION
Large engines have always been highly efficient compared to other engines, and the ^plicati(Mi of technology has proved successful to this extent It is clear, the large number of runiung boiirs and the high mean load ofthe engine make fuel costs a very important item, and relatively high costs can be invested to the purpose pf obtaining lower fiiel consUmptioiL With respect to low emissions, measures to improve efficiency are frequently counterproductive. Nonetheless it can be expected that sooner or later, dependant on the applications, emission requirement will become impor^t In that case it surely m ^ s good sense to review the truck technology for use in larger engines.
At the mpment emissions are the driving force for intensified research and development for truck engines. In the past TNO Road-Vehicles Research Institute have successfully focused on altemative fuel applications, winch apre highly effective for meeting the stringent emission requirements for urban transport. However it is realised that for long distance heavy goods vehicles, Diesel pPwer and Diesel fuel will be predominant for the foreseeable future. For this reason TNO are broadening dieir activity in the area of Diesel engines, initially beginning with combustion properties of Diesel fuels, and this year work has begun on aspects Pf these engines.
In this presentation, an overview is given, based on available Uterature âs well as initial results fiom TNO, of die emissions legislation, and the responding technology expected to be applied to ne\y truck engines m the corning 10 years.
2. TRENDS IN EMISSION LEGISLATION FOR TRUCKS
With respect to truck engines, rnost European legislation has been aimed primarily at reducing NQx emissions which ccmtribute to acid rain, and particulate emissions whicfa are firstly suspected to conträ>üte a hurnan health hazard, and secondly, wheùtôr health hazard or not aré objectional in urban environinents.
To look closer at NOx émissions; although at pr&sent in Europe the main contributor ts the petrol passenger car, this source is so effectively being cleaned up by the use of 3 way catalys)^. that it is predicted that it will not be long before the largest transport source of NOx becomes the heavy dîity truck, and thus it is reasonable to demand action. See Hgmë 1. Policy makers in the Netherlands (1)* are planning on a reduction of NOx from die truck fleet by die year 2010, to a level of 25% of die 1986 baseline (Where typically a truck was estimated to give some 14 to 18 g/kWh NOx over the 13 Mode cycle), by the following actions:
Footnote Nnmbers shown ia psaenttmes {) refer to the list (preferences shown in secticm 7 (rf this report
3-• 50% Réduction of NOx emissions in die short term duough en^iie lepslation.
• A further 25% reduction (ie. a fixrthsr halving) in the longer term through further legislation. The assumption behind this decision is that technology will provide a solution.
• Better cpntrplled transport, and more efficient fuel consumption (per km) to curb die expected rise of emissions due to die expected increase (40 to 80%) in road freight haulage.
Despite the obvious uncertainties in this predicted approach, it is certain is that hard hitting NOx emission legislation for trucks in Europe is to continue, and it is justifi2d>le.
Figure 2 shows EEC Ermssions legislation dnectivfô for the present and short term future. Although talks are proceeding in Europe aboiit having some form of CO2 emission limit directive, the discussions are at the moment only about passenger cars.
3. THE TRÜCK TECHNOLOGY IN 2000
3.1 Fuels
3.1.1 ConVéïHUmàl f ÜIBIS
The trend here is clear. Faels witjh a low sulphur and low aromatic content are expected to become almost universally available. These are to iinplemented because of associated lower particulate levels attainable with such ftiels, and the ability to use an oxidising catalyst to good effect for reduction of die soluble fraction of particulates, HC and CO.
The current status ofthe iiitroduction of clean ftiels is briefly summarised as betow. (2) • California : 0.05% S and 10% Aromatics fiiel to be introduced from l/l()/93
• US : 0.05% S and minimum Cetane No 40 to be iiitroduced fi'om 1/10/93
• EEC : The EEC have rnade the decision diat low sUlphiir (0.05%) fuel will be available for both certification testing and use in the near future. (Most likely 1994/1995)
• Sweden : Titrotigh a series of tax incentives, 3 classes of "EnvironTmental" Diesel fiiels are being currently encouraged, which thclu<te very low levels of Sulphur, as well as low aromatic and PAH content
TNO have considerable experience in the testing of some of the more popular European current truck engmes over the 88/77/EEC 13 mode test on both ciurent and future Diesel fiiel types. It is on diis diat they base their opinion that with low sulphur and aromatic fiiels, die proposed 1995/6 European emissi(m legislations should be achievable or approachable on
-4-most truck engines without "Extreme measures" (Figure 3 aid Figure 9) but the associated loss of engine efficiency would not be considered acceptable for such a competitive market
3.1.2 Alternative fuels
Although altemative fuels are unlikely tp see usage in road haulage trucks, their usiage in urban and local vehicles warrant their mention. Two such alternative fuels are seen as particulariy promising:
i) Gaseous fiiels
Otto-cycle engines with three way catalysts give very low emissions mainly âs a result of the high efficieiicy of the catalyst This technology is of course applied to petrol cars on very large scale. These engines require very accurate fuel systems that are able to control the air-fuel ratio within die narrow catsdyst "window" (very close to stoichionietry). In this window the catalyst has a high efficiency to itdiice NOx. and oxidise HC and CO emissions.
For local transport by trucks and buses this approach appears tp be an interesting soliition, and because of good combustion prpperties and gpod safety reasons natural gas is promising. The worid natural gas reserves are at least comparable with that of fossil fuels, although they are largely sited in areas with uncertain political stability.
The energy efficiency of such engines is pn average about 20 % lower than comparable Diesel engines. Thüs is due to a lower cycle efficiency and to throttiing effects of the throtde valve at part load (3). However, because of the favourable H/C ratio of natiural gas compared to Diesel C02 emissions are comparable.
Serious drawbacks of the stoichiometric gas engine are the in-cylinder component temperatures which are very high, and in some cases there exists an upper limit on attainable power diie to the ons^ of detonation. By application of a lean mixture (Higher air/fuel ratio) this problem can be dimimshed However emissions of lean burn enguoes are less favourable. In Figure 4 results of three different gas engines developed at TNO are presented.
ii) Methanol
By the application of methanol it is deinonstrated that very low particulate emissions can be obtained with a IMesel eiïgine. The cetane number of methanol is very low, therefore either an ignition source in the cpmbiistion chamber is needed or a cetane improver has to be applied. An example of a so-called spark-assisted methanol engine which is shown in Figure 5. This is a Diesel-cycle engine, thus the efficiency is comparable with other Diesel engines. Methanol can be produced from high temperature and pressure catalysis of natural gas. At present there is an associated circa 25 % feedstock energy loss, though more advancied processing system should be able to reduce this.
Major drawbacks of methanol (3) are as below:
-5-Medianol is deadly toxic either from inhalation, intemal consumption, pr long term skin conmct It is also odouriess and tasteless, and unlike Petrol of Diesel fuels, is not sp well known publically as being poisonous. Methanol Is alsp intoxicating.
Methanol is fiammable to a level comparable with petrol though the flame produced by med^onpl combustion is largely invisible. With respect to transport ^ety, it should also be bome in mind that the 56% Lower energy content of methanol per unit volmne. conipared to Diesel, results in circa twice the required volumes tp be transpprted.
3.2 Engine development
It is of course recogiiised that diere is rarely one factor which whUst productive for one effect, is not cpimterprodiictive for another, and whilst trends can be drawn as to how the varioits parameters involved are changing to give cleaner engines, it should be remembered that the resulting range of eiigines will still be widely individual depending upon their application, and maniifacturers may vary in their chosen approaches.
3^1 General
Out of interest it is expected that many of the truck Diesel engines are expected tp be taking oii some similarity with Medium Speed engines. F6r example:
i) For tlie larger truck engines, spme authorities (5) are advocating the use of wider bowl lower swirl combustion systems as opposed to swirling deep bowl systems in current European use. (With smaller engines however good results are being demonstrated with re-entrant bowls (6))
ii) Peak injection pressures are expected to be rising to at least 1100-1400 bar.
iii) Attention is expected to be given to mid speed boost problems.
iv) Turbocharging and aftercooling (Air/Air) is expected to become more widespread.
With respect tp iii) Figure 6 illustrâtes how the mid speed full load air/ftiel ratio is particulariy important within the European 13 mode test for particulate emissions, and good air utilisation and avaüabUky is ^âtal.
me
-6-Widi special regard to iv), lowering of the compression ratio in order to accommodate the higher Pmax values associated, will probably not be acceptable because of resultant high light load particulate emissions. In some cases (older engines) this may necessitate reassessment of dne engine design for higher Pniax values.
In the following sections, meaisures are discussed to iniprove the trade off between NOx. particulates and efficiency.
3.3.2 High pressure fuel injection
Here ertiphasis is on veiy high injection pressures which must be mmntained over a wide range of speeds and loads (5). Because pump and injector pressures can be a limiting factor^ and because highest pressures are seen at full power, as flat a pressure against fuelling
iEësponse as possible is desirable. In pursuit of this, ultimate pressure ûs sometimes sacrificed
for an increase in pressure at maximum tprque speed. For this purpose although the choice between pump/pipe vs. unit injectors is still not striaightforward, the in line pump/pipe injection system is certaiidy still attractive and is expected to find favour in Europe. Althous^ electronic control of timing and injection r^e fpr such systems is not es^ntial for attaiiiing the European legisl^on. the flexibility for light load and cPld starting advance, and potential economy gains pf such systems should make its use widespread.
Nozzles are exp^ed to contibnue their trend towards low sac or VCD*" types which give reduced HC and particulate emissions.
3.3.3 Improved breathing
In the 21^ century 4 valve large truck engines are expected to be in use in both Europe and the US. (Again a trend is shown towards the Medium Speed engine corifiguration) These give a twofold advantage to the truck Diesel enghie:
• linproved breathing efficiency and a consequent better torque backup and fuel consui]p{>-tion.
• The ability to use a central and vertical (or near vertical) injector. This then allows for lower nozzle sac volumes to be used, wtdi symiiietrically drilled holes with better fiow characteristi<^ This yiields a reduction of particulates.
* VCO = Valve Covering Orifice
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-7-Maxinium rïüd speed torque backup is an important for good drivability and sujfUcI^ airflow is irnportant for low smoke emissions and transient response. Developers of medium speed engines for fast patrol boat or similar appUcations will recognise a cornm(m mterest here and be aware of the various "Air management" systems which have been attempted over the years. (For example Variable georiietry mrbines. Sequential turbocharging, mecionically or pneumatically assisted turbochargers, turbocompounding ete) Many of these wÜl not find place on the Truck Diesel of 20Ô0 because of die importance of optiinum fuel consumption and reliability. Interest has so far been shown in, for example, Variable geonaeby turtnnes, turbocompounding, sequential turbocharging arid mild wast^ating. TNO have in the past carried out first order siinalations to assess the potential of a few such systems. Examples are shown m Figure 7. It is thought that attention will be given to wastegating, because a mild degree of wastegatirig at full power, may not result in an overall fuel consumption penalty. A recently announced range of Turbocompounded trucks may look favourable in the coming years. This Is because of their better transiâit response and ability to regain valuable energy at the heavily retarded timings required for low NOx emissions.
However it is felt that in the main European market as well as for smaller trucks, air management will fiirther improve through continuing technological improvements tp the design and fabrication of the turbocharger, yielding better thermodynamic efficiencies, structural and thermal integrity, and higher speed capacity. (7)
3.3.4 Injection retard and/or EGR
NOx emissions are generally not very sensitive to APR or conipression ratio. Timing retard plus air to air charge cooling provides the most effective way of reducing this einissipn. This is shown in Figure 8. With respect to the degree of timing retard. European TCA engines are expected to require some 10 to 12 degrees of retard fiom the maximum efficiency setting to meet the 1996 EEC NOx emission legislation and may yield some 6 to 8 % fuel econoiny penalty, whidi truck manufacturers will try (and probably largely succeed) to regain dirough; inproved fuel injection systerns with higher injection pressures described above, and increased compression ratio. These measures should also help keep higher particulate ennssions associated with retarded injection und^ control.
An altemative to injeetipn retard for NOx reduction, is tP apply exhaust gas redrcuMon. In this case an improved trade off between NOx> particulates and efficiency can be obtained. Although the piredicted use of low sulphur fuel should reduce the wear problems of this approach, it is still an undesirable complication for heavy duty trucks. For light duty engines however. EGR is widespread.
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-a-3.3.9 Exhaust gas aftertreatment
i) Particulates
With the introduction of low sulphur fuel to the European market, the exhaust gas oxidation catalyst must represent one of the simplest ways of reducing ermssions, without econpniy Ipsses, for tfae future. Significant reductions of CO HC and the soluble fiaction of particulates can be achieved, particularly at the high load pdnts so impor^t to die 13 mode test Hgure 9 shows expeded results. (Estimated fiom particulate composition data)
Traps and catalyst traps are now in tndls for infoan transport throughout Europe. Even so a fully dependable trap is expensive. (Currentiy circa $15.000,» for city bui$ type engines, although diese are only in limited production numbers) tt is not thought that such traps are likely to be used on large road haulage trucks where the particulate emission legisl^pn is
mate generous dian the cprresponding levels for city busses.
"JNOx
DENOx (One way) catalysts which can reduce NOx in äo oxidising environment are iinder development (8)
Selective NOx reduction is a known techniqtie already a l l i e d for I ^ e Diesel engines. Systems are under development widnn the Netherlands that are able to function properiy also under varying load thus making such systems applicable to Diesel trucks. However, the potential hazards of a serious ammonia emission, dictate that sucfa a systent must show exceptional reliability before application could be considered a possibility.
3.3,6 Engine managentent and diagnostics
Engine management systems are applied to obtain eimssipn limits with more competitive performance. These systeins are in production, and many new cars are equipped with such systems.
New approaches are under development, also at TNO, which niake use of known relations of engine behaviour tp check and/or replace sensor readings, thus obtaining mcreased reliability. These so called "Functional redundancy" systems are expected to be seeing increased use on truck engines as the introduction of electromc controls advances.
Closed loop systems on petrol passenger cars have been deinonstrated to provide excellent confirmation with legislation over the vehicle's Ufetime (9). It is not unthijakable that some similar system could be apphed to the Diesel engine management systems.
-3-4. TRENDS IN E M i ^ l O N LEGISLATION FOR MARINE DIESEL ENGINES.
In view of current tight emissions legislation on dié Califomian coast, requiring SCR in some appUcatfons, as well as the stringent tightening of emissions legislation in many countties for comparable engines when used for stationary generating duties (See Bgure 10). the marine engine manufiipturer must sorely be concerned whetfaer he is likely to see Legislatian ^^pUed to his product in the same severe manner that it is being applied to trucks. To assess tfais possibilify tfae foUowing are in^rtant considerations:
• As a global contributor of NOx emissions, niarine Diesels are probably nPt significaiit and are unlikely ev^ to be so. Huis the argiirnent 2q}pÙed to truck engines (Section 2) is not stniMigin this case.
• Legislation for sea going vessels would have to be international and would [^obably he difficult to implement TNO are nPt currentiy aware of any UN discussions on this subject to date.
• Countries (or states) may io^se legislatipn covering their inland and/or 5 mile coastal boundaries. With respect to the latter faowever, this becomes unattractive because it inevitably leads to trade lost to ports in nearby countries.
• Stationary engines should not be used as coniparative measure here because a) They are a fixed enaissipn source and thus legislation is easier to implement b) Tfae clairned reason for strong emissions legislation faere. is tfaàt tfae use of sucfa engines for cogeneration purposes is rapidly increasing, and emission legislation is being applied before these engines become a sigiiificant source of ppllution.
• Specifically within the EEC. sharp emissions legislation through obligatory directive is ofien avoided because ofthe need for all 12 countries to agree to its inaplementation. Furthermore. EEC directives have dways been based on reasonable and previously demonstTEU^le solutions, unless a clearly seen urgency is required for a rapid clean up of technology. For marine NOx emissions, no such urgency has been demonstrated yet.
However, because of tfae political nature of emissions legislatiloh, ahd tfae favour found in the "every polluter pays" approacfa, TNO expect that in the future more countries, starting of course with those which are strongly environmentally conscious, wUl be imposing legislation
iipon marine Diesel en^nes. In anticipation of (fais, there is now a draft ISO agreement (ISO
8178) which covers test procedures for non automotive internal conibustion engines, and includes a procedure fpr constant speed ship propulsion engiiies.
Thus in conclusion. TNO expect marine engine emission legislation to become more widespread, and in some areas severe, though h is tmlikely that countries vyiU apply such universaUy accepted or ^trmgent legislation as the case is with truck engines.
ia»
-10-5. EVALUATION OF TRUCK TECHNOLOGIES FOR MARINE DIESB. ENGINES.
5.1 General considerations
To be able to evaluate truck technolos^ for larger engines, one sfaould faave in mind the fPllowiUg differences of the large engine compared to die truck engiiie.
• Different emission taigets. (if ^ )
• The annual running hours and load factprs of tfae large engine are higher. Tfaerefore the investment to reduce fuel consumption can be higher
• For large engines, rugged reliability is paimount.
5.2 Engine technology
With a view tp the above considerations, it is suggested that truck tecfanology may be of interest to the marine Diesel engine maimfacturer or user, wfaen faced with tfae problem of rediidiig exfaaust enüssions on his engine. The application of die necessary technology would of course depend upon the magnitude of the reduction required.
i) For severe emissions legislation the following may be of interest: - Exhaust gas aftertreatment whether catalyst, or trap, or SCR systems.
- Alternative fuels, whether these be low sulphur distillate or methanol with cetane improver for short periPd operation in areas where stringent emission legislations apply, (eg Haibours)
ii) For moderate emissions legislation the following may be of interest:
- Rdt£u-djed and perhaps electronically controlled (eg (10)) injection tinting with increased cpmpression ratio or boost pressure to maintain efficiency.
- Air management and control.
- Greater implementation of engine management sy stems.
- Combustion optiinisation with a view to low NOx emissions, (eg. combustion profile optimisation for low peak temperatures)
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-11-6. CONCLUSION
It is hoped that a summary and satisfiictory overview has been given faere on reasons for, and measures taken towards exhaust emissions legislation for heavy goods vehides in Europe. It is certain diat altiiough in general, truck engine and large engine emission requiiements will be quite different, as are their duties and operating conditions, many large engine mêanüfiacturërs will have to review the options available to them fi>r reducing emissions. In some locallised cases (as is ciurently being seeii for exainple on the CaUforidan coastline) the reqmred Umits are very low require extreme measures, and the truck technology becomes of Uttie iio^erest HowieviÉsr it is felt that in other and perhaps more widespread areas, more demonstrateable and viable limits may be demanded, and in t l ^ instance the marine Diesel develops can gmn considerable insight from the experience of triick engine manu£u:turers.
It is also of interest that in some cases, tfae approacfa taken by the truck engine developer is in some way tending towards medium speed engine configurations. This sprt of engine has of course been weU optimised for good air utilisation, and therefore is of interest with respect to low particulate production. Thus it is perfaaps possible that technology could also fiow fioin marijöe to truck Diesel engine developers.
-12-7. REFERENCES
(1) - Netheriands Ministerie van Verkeer en Waterstag. Report 20 922. "Tweede Struktuurscfaema Verkeer en Vervoer"
(2) Concawe repprt No 3/91. "Motor v ^ c l e emissions regulations and fuel specifications -1991 update"
(3) - "The application of natural gas in busses in the Netheriands" J, van der Weide et aL NOV 90 conference Buenos Aires.
(4) - TNO Rqport 731060069. "Methanol als MotodtrandstoT J. van der Weide et al.
(5) - SAE Report 891949 "Technology for 1994" Needham, Doyle et al.
(6) - SAE Report 905073 "Optimising the six Utre Diesel for low enüssions" Doyle, Faulkner etal.
(7) - SAE Report 900356 "Design and development of the Holset HX series of turbochargers" Dewhirst, Mc Ewen et al.
(8) - 12^^^ latsänatiooal Vienina Motorsyinposium, April 1991, "Entwicfcelungsfortschiitte bei PKW-Dieselmotoren zur Efullung künftiger enüssionanforerungen" Burgler, Herzog and Zelenka.
(9) - Netherlands Ministerie van VROM. "Project in use compUence air poUution by cars in use 1989-1990" (TNO Report 733039000)
(10) - SAE Report 88030092 "Development of an electronic fuel injection system for inedium speed engipes" Usui. Ikizawa and Itoh.
-13-Rgure No 1 : Estimated NOx Emissions Firom Traffic Sources Wrthin the Netherlands
180 T 1989 3 Way Catalysts tntroduoed throûgh Tax incenthm - 160 .r^ 120 ë 60 llnrèstrictèd Rrätrictad
-A
1 1 1 ( 1 — I 1 ^ 1 1970 1975 1980 1985 1990 1995 2000 20C® 2010• Heavy Duty Dlasel Engines O Petrot Pasenger cars
Figure No 2 ! European Emtsstens Legislation Development over time « M à J a C O t a / k W h l 20 T 15 + 14 10 + 11.2 4.5 H \ 1 1 1 1 1 1 «VI <ç g S ai o> 1 3 Mods NOK (Q/kWM 20 T 15 + 10 + 5 + IS 14.4 H 1 H 1 1 1 1 1 9a Kf^ cti OTl ^3 13 Mods HQ laflcWhl S T 4 + 3 + 2 + 1 + 3A 2.4 1.1 -* 1 h H 1 1 1 en ^ t o m C l ^> 13 Mods Partteulatss WkVVhl 1 0.9 0;8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 EriQlnM > 86kW UnlliMnd < seiiw Afl StfdtttlM H 1 1 1 1 I 1 1 90 iP gi cn CT» <y% 9> cjt cr> ^9
Roure No 3 : S nopular tmck enoînea sold in The Netheriands Tested over tha PCE R49 Cvcle Engine 1 » 12 litre TCA (Air/Air) with 9 g/kWh NOx Certification
Engine 2 » 12 litre TCA (Air/Air) Engine 3 -> 10 Btro TCA (Air/Air) Engine 4 = 8 litre TC
Bigine 5 " 6 litre NA with 9 g/kV\/h NOx Certification
13 Mods HOM Engina No 13 Moda CQ Eniairw No 0.25 0.2 0.15 + 0.1 + 0.05 13 Mods Psrtteijlates Engina No 13 Mods HC Engins No
Rgure No 4 : Performance and Emisston Charactaristies of 3 Tmck Size Natural Gas Enoinea
EfBdsney at Maximum Tofous Ssssd
BMEP (Bart 7 T 6 + 5 + 4 + 3 + 2 + 1 + Europaan Umit 1996 20
88/77/EEC 13 Moda Emlaalona
Lsan Sum Engine No 1
Lean Burn En^ne No 2
Lsan Burn Engins N o 1 Lean Sum Entfna N o 2 Stoichioirmoto engirw a CO
a
HC • NOx s toichiomefirio engins-17-FTgura No 5 : Spark Inanited 100% Methanol Fuelled Ehoina
Technical Data : MAN 2566 LUH Methanol engine Fuel: 100% Methanol
13 Mode NOx 1 5.3 g/kWh 13 Mode HC : 0.18 g/kWh 13 Mode CO : 0.19 g/kWh
13 Mode Particulates : 0.07 g/kWh (Measured in Transient Cycle) Maximum BMEP
NaturaUy Apsirated » 9.4 bar Turbocharged » 13.2 bar
^ ^ ^ ^ ^
/
Acknowredgements MAN Nürnberg
Ref : MAN Methanolmotoren fur den Einsatz in Stadtomnibussen ETH & SSM Symposium September 1989 Khorr et al
Roure No 6 : Percentage Contribution of Individual Modes to 13 Mode Emission Results for S European Engines
WOx Particulates £ 2 ^ ë ^ 6 5^ — — «NI i r t ^ _ 5 5 5 5 = i -s i OC 200 S 140 -s- 120 e« . •« M M S S S S K S 5 5 5 5 1 3 9 5 S 5 5 5
Rgure No 7 ; Simulated Results of 2 "Air Management" svstems on TCA Truck Enoïna Efflcianev
Aaaasemsnt ot Turbocompoundsd nm non Turbocompounded Bïotn» BSFC at fan load
— 260 f > 240 + 220 • -215 • ^ 2 1 0 • ^ 205
I
1 200 -195 190TCA at Max Power
With cornpounding at htoi Power
TCA at Max Torqus
With oornpouncfoig at Max Torqiw 1 •• :
5 10 IS Oegi-eéa of reterd friom point of beat effictaney
AsseaahiiBrit of mHd dearee of waeteaatino on TCA truck enofne 110'i^ Waataaata/Turblne flow at maxiiawafi
20 , (28:8) (28,8» Conventional (21.3) _ ^ Wntegatad (23.2) ^
Figures shown in parentheseaO refer to tha air/fuel ratio at that point
f 1 h 1 1—- 1 1 1 1 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
Rgure No 8 ; Effect of timing retard on aitiaaions and Fuel Consumption (12 litre TCA Truck engine)
13 Mode WDx
Static Injection Tinning CBTDC) 13 Mode HC "g 0.35 0.3 0.2B 0.2B 0.2 0.15 0.1 0.05 0 18 14 10 Static Nection Timing CBTDC)
Minimum BSFC ovof 13 Mode Test IMax Tordue 100% load notntl
m
18 14 10 Static Injection Timing CBTbC)
0.18 0.16 0.14 0.12 0.1
i
0.06 0.08 0.04 0.02 0 1-:? 1 i 0-8 > g 0.6 gl M 0.4 0.2 O 13 Mods PsrticûlatBaStatic Injection Timing ("BTDC) 13 Mode CO
^^^^^^^
18 14 10 Static Irijection Timing CBTDC)
Roure No 9 : 5 popular tmck engines sdd h The Netherlands tested over tha ÉCE R49 Cvcle Engine 1 » 12 Titre TCA (Air/Air) with 9 g/kVVh NOx Certification
Engine 2 a 12 litre TCA (Air/Air) Engine 3 » 10 litre TCA (Air/Air) Engins 4 ^ 8 litre TC
Engine 5 ^ 6 litre NA with 9 g/k^/Vh NOx Certification
0.45 -r
Estimated 13 Mods Particulatss & 7 o/kWh NÓ»
No 4 7 N04 7 1996 Limit ^ Engins No 1 • Engine No 2 @ Engine No 3 Engins No 4 S Engine No 5 Std Engine Rstarded to 7 g/kWhNOx
With Low Sulphur Fuel
VVith Low Sulphur Füai and Catalyst
Results estimated from Particulates composition and assuming SOF cbnyarslon effiueney
Roure No 10 : Approximate NQx emission limtts for stationarv Diesel engines in some European countries
(Acknowledgements : Stork-Wartsila Diesel B.V.)
30 -25 — J 20 -: â 1^ + § s 5 4f= ^ 2 S S S f r -r 4 ^ 1
Approximate values of excess air factor (Lambda) and ongirts effîdencies used :• Large Diesel engirîaa : Lambda « 2.6 , Shaft éffîciency 44.5%
Small Diesel Engines : Lambda » 2.0 , Shaft effieisncy 35.0 %
B6TROIT DIESEL
eeNcuix BM.
M :) Dl I DETROIT DIESKL ^>ITRODÜCES C O M P i m
ELECTRONIC CONTROLS FOR COMMERCIAL MARINE ENGINES
AMSTERDAM, NETHERLANDS, November 1, 1991 - Detroit Diesel Corporation (DDQ» creating a wave of ûie future in marme power technology, has introduced a revolutionary coinputerized electronic engine goveniing aad fiad injeqdoii system for Detroit Diesd Sernis 71, 92 and 149 marine commercial engines. The new Detroit Diesel Electromc Control (DDEC) system is the first totally integrated dectipnic control tedmology available in die nuurine power industry.
"^e believe that DDEC for cômnieàrcial applications is the wave of new tedmology whicfa wUl revolutionize die way tbe marine industry uses dectronic control tedinology. Hiis isa*t just m add-on tedmology. Tfae DDEC tedmology is totally int^rated - ftom dee decteonic conttol module ri^ down to the electromc fud mjectors," said Al Kozd, DDC vice president, marine sàles.
The DDEC system is based on the operation of two m^or components, the Electronic Control Module (ECM) and die Electronic Unit Injector (EUI). When combined widi DDC-supplted operatpr co:ntrol systems, diese components become the b r ^ and beart pf die total integraticm tedmology of DDEC," eiqilained Tim Tindalt, DDC director, [urbdua engineering -Series S3, 71, 92 and 149 engines.
"We have designed rdid^ility and redundancy iztto the DDEC system," siüd Tindall. "Detroit Diesd introduced the DDEC tedmology in our ov^-dte^road applicatipns in biisses and trucks in 1985; Over 90,000 DDEC-equipped engines are in operation today. Because of our lead^hip m engine dectronics, we are confident dia^ DDEC engines wUl change die future of die marine industry dramatically."
A patented dectronic unit injector is at the center of die systism. The mwhî^nîify! rack and hdical madiined surface on the plunger is replaced by an dectromcdly-controned sc^enoid valve and straight plunger. With its simplified mechanics, die EUI provides more effective relation of föd injection tö the cylinder. With die constant monitoràig of die power fimction of all sensor input by the ECM, the system automatically condensates to assure that the engîiœ per^ninance is maintained at i ä niost effective level.
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-"ihe new DDEC technplogy for commercial marine applications wUl vütuaÜy dimmate the need for dme^nsuming tune^ps. It will supply buUt-hi engine synchronization, on-board system diagnostics and, most importantiy, early vrândh&i for engine malfunctions . . . before damage occurs," said Tindall. "The totdly integrated systean will improve ovendl boat perfonnance."
Skippers of boats widi die DDEC syst^ will immediatdy sense the responsiveness (Kf their crafts, at bodi h i ^ and low speeds. DDEC will diminate the "control lag" of mechamcd engine goveming syst^ns and cable controls.
October, 1991 — G.M. BlPiDoi, owner aiid ca^pûôh of the motor vessdl Johanna operating in The Nedieriands^ SKplamed, "The new Dettoit Diesd dectronicdiy controlled (DDEQ gV-92tA engines allow me to run at higher vessd speed without a fud consunqjtion pendty. My iHiimd runs across the Amsterdam-R^n Cand, with the now replaced Deutz engines, used to take tne 4-1/2 hours at 12 km/hr. Widi my new Detroit Diesd DDEC 8V-92TAs at 365 bhp, the trip now takes 3-1/2 hoi^s st, IS km/hr.
"I know instanteously from the DDEC engine nipnitoring system my fiiel consum^tdcm
wd boat speed. I then znatch the Johanna's speed widi engine RPM, allowing me to operate at
die optinnim RPM for best Aid consumption and boat speed. My totd fud consunqMion remams the same while I cut my operating time by one-quarter," said Blom.
"My trip across die W ^ Bg Duurstede to Wijhe widi the new engmes allows me diree hours additiond sleep - very miportant! these engines are the diftereôoe b ^ e e n arriving at 2:00 ajDl. vmus 5:00 ajii."
"The DDEC engines haye dimkated exhaust smoke and have à much lower noise levd, making the cabm much more pleasant. Fm verv satisfied widi die inproved performance and b^ter work anvironment provided by my Detroit Diesd eoi^nes," said Blom.
DDEC will einable manufacturées to offer five power options from the Detroit Diesd 6V=^TA widi 325 bhp at 1800 rpm to die 16V-149TI widi 2400 bhp at 2100 rpm.
DDEC comes standard with Liquid Crystd Displays (LCDs), Vilich replace mechamcd gauges commonly found on board boats powered by mechanicd engmes. The DDEC LCD provides a variety of mformation, such as oü pressure, engnie temperature, transmission preisÄire and temperanu^ tachometer ai^ fud consun^ïtion, convenientiy located on one screen per engine.
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-The PpticHid Cathode Ray Tube (CRI) displays provide total on-board system imegratipn^ hidudis^ Loran, auto-pilot ahd darm systiem.
Also provided by DDC are single or ûva^ lever gear and throtde controls fi» tq> to six stations.
DDC win contmue to offer its current line of mediamcally-cohtrolled commercid eo^gmes, rangiug filom 270 to 1440 bhp.
But most h^rtantly, manufacturers and boat ownerâ will be able to rdy on die years öf Detroit Diesd marine power experience and its woridwide service network.
Begiraùiig operations oh Jaraiary 1, 198S, DDC is a joint venture conqiany whidi is $0 percent owned by Penske Transportaticm, Inc. and 20 percent owned by Generd Motors Coiporation.
Detroit Diesd Corporation designs, maauâctmres and sdls diesd engmes for die highway, cohstructidn, industrid, marine, military and stationary power markets.
Detroit Diesd manittiactures and markâs engines ranging in horsepower from iqiproxhnatdy 5 hp to over 2400 hp.
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Detroit Diesel
Electronic Controls
(DDEC)
"Detroit Diesel is the industry leader of electronically con-trolled engines. First intro-duced in 1985 to the automo-tive industry, there are now over 70,000 D D E C equipped engines operating in highway trucks, transit c o a c h e s and marine pleasure craft... now D D E C is available on Detroit Diesel Series 71, 92 and 149 commercial marine engines. DDEC is a computerized elec-tronic engine governing and fuel injection system that replaces mechanical controls in Detroit Diesel engines. In addition, within its onboard computer DDEC offers engine protection and self-diagnostics to identify malfunctions in its c o m p o n e n t s as well as the ability to troubleshoot engine problems."
Major Components of
DDEC are the
Electronic Control
Module (ECM) and
the Electronic Unit
injector (EUI)
The ECM Contains:
• A microprocessor lhat continu-ously monitors and analyzes the D D E C system with electronic sensors during engine operation. • A p r o g r a m m a b l e r e a d - o n l y
memory (PROM) thai provides instructions for b a s i c engine control functions.
• E l e c t r o n i c a l l y e r a s a b l e , pro-grammable read-only mempry ( E E P R O M ) that stores engine calibration values,
• A b a c k u p E P R O M . E E P R O M and microprocessor to operate the e n g i n e s h o u l d the main microprocessor fail.
With this redundancy built into the ECM, reliability is assured. In fact, of tfie 70,000 DDEC units we have in operation all over the world, we have never had a failure of the backup microprocessor.
Electronic Unit Injector (EUI)
• Buiit on our palented
mectiani-cal unit injector design.
• Design simplifies plunger and replaces mechanical rack with an electronic solenoid.
• Allows precise'm§terTi injection timing
The EUI IS actually simpler in the area of the plunger ^^ieS^iiShi
than the mechanicaf unit inKtor.
The amount of fuer injected and the timing are d e t e r m i n e d by information f e d j Ä o the E C M from
sens^ors^lQOeted on the engine
MECHAN tZATtON
