Contents

The Intelligent Engine:Development Status and Prospects

Page

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Development Goals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

The Intelligent Engine Concept . . . . . . . . . . . . . . . . . . . . . . . . . 3

Design Features of the Second-Generation IE System . . . . . . 6

General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Power supply system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Fuel injection system, design features. . . . . . . . . . . . . . . . . . . 7

Fuel injection system, rate shaping capability . . . . . . . . . . . . . 8

Exhaust valve actuation system . . . . . . . . . . . . . . . . . . . . . . . 11

Control system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Cylinder pressure measuring system (PMI) . . . . . . . . . . . . . . . 12

Electronic cylinder lubricator . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Advantages of the Intelligent Engine Concept. . . . . . . . . . . . . 15

Service Experience with the Intelligent Engine 16

Design of IE systems for M/T Bow Cecil . . . . . . . . . . . . . . . . . 16

Service experience with IE systems on M/T Bow Cecil. . . . . . 16

Commercialisation of the IE Concept . . . . . . . . . . . . . . . . . . . . 19

Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Introduction

This paper will discuss MAN B&W’sdevelopment of computer controlledlow speed crosshead engines andthe application prospects for such‘Intelligent Engines’. Computerisedsystems, e.g. for cargo management,satellite navigation and satellite com-munication, have been used for quitesome time in merchant vessels. How-ever, the market has traditionally notfavoured having electronics inte-grated as essential parts of the mainengine – an exception being the useof electronic governors.

We believe that this situation willchange over the next few years, ashas happened in the automobile in-dustry over the past 10-15 years. Theneed for flexibility to cope with diver-sified emission limits and increasingdemands for reliability will undoubt-edly lead to comprehensive use ofelectronic hardware and software inmarine engines. This is why we es-tablished a separate Electronics &Software Development Departmentsome years ago, with hardware andsoftware expertise and the capacityto do professional development work.

This significant investment in devel-opment capacity was not only meantfor the development of our future‘Intelligent Engine’. We also use it todevelop building blocks of hardwareand software systems that can beused with the conventional enginesin our current programme. This willenhance the reliability of conventionalas well as ‘Intelligent’ engines andfacilitate new applications – for theformer provided, of course, that theowners are prepared to invest in thenew systems and that the crews usethem accordingly!

Development Goals

The basic goal of the development isto reduce the cost of operating theengine and to provide a high degreeof flexibility in terms of operating modes.

The three major areas of concern in thiscontext are:

• Enhanced engine reliability:

- on-line monitoring ensures uniformload distribution among cylinders

- an active on-line overload protectionsystem prevents thermal overload

- early warning of faults under devel-opment, triggering countermeasures

- significantly improved low load op-eration.

• Enhanced emission control flexibility:

- emission performance character-istics optimised to meet local de-mands

- later updating possible.

• Reduced fuel and lube oil con-sumption:

- engine performance fuel-optimisedat ‘all’ load conditions

- ‘as new’ performance easily main-tained over the engine lifetime

- mechatronic cylinder lubricator withadvanced dosage control.

The Intelligent Engine Concept

To meet the operational flexibility target,it is necessary to have great flexibilityin the operation of – at least – the fuelinjection and exhaust valve systems.Achieving this objective with cam-drivenunits would require substantial mechani-cal complexity that would hardly contrib-ute to engine reliability.

To meet the reliability target, it is neces-sary to have a system that can protectthe engine from damage due to overload,lack of maintenance, mal-adjustment, etc.A condition monitoring system must beused to evaluate the general engine con-dition so as to maintain the engine perfor-mance and keep its operating parameters

within the prescribed limits and to keep itup to ‘as new’ standard over the lifetimeof the engine.

The above indicates that a new type ofdrive has to be used for the injectionpumps and the exhaust valves and thatan electronic control and monitoringsystem will also be called for. The re-sulting concept is illustrated in Fig. 1.

The upper part shows the OperatingModes which may be selected from thebridge control system or by the intelli-gent engine’s own control system. Thecontrol system contains data for opti-mal operation in these modes, whichconsist of a number of single modescorresponding, for instance, to differentengine loads and different requiredemission limits.

The fuel economy modes and emission-controlled modes (some of which mayincorporate the use of an SCR catalyticclean-up system) are selected from thebridge. The optimal reversing/crashstop modes are selected by the electroniccontrol system itself when the bridgecontrol system requests the engine tocarry out the corresponding operation.

The engine protection mode is, in con-trast, selected exclusively by the condi-tion monitoring and evaluation system,regardless of the current operatingmode. Should this happen in circum-stances where, for instance, reducedpower is unacceptable for reasons ofthe safety of the ship, the protectionmode can be cancelled from thebridge.

The centre of Fig.1 shows the brain ofthe system: the electronic control sys-tem. This analyses the general enginecondition and controls the operation ofthe following engine systems (shown inthe lower part of Fig. 1): the fuel injec-tion system, the exhaust valves, thecylinder lubrication system and theturbocharging system.

Some of the control functions forthese units are, as mentioned above,pre-optimised and can be selectedfrom the bridge. Other control func-

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The Intelligent Engine:Development Status and Prospects

tions are selected by the engine con-dition monitoring system on the basisof an analysis of various input fromthe units on the left and right sides ofFig. 1: general engine performancedata, cylinder pressure, cylinder condi-tion monitoring data and output fromthe Load Control Unit. More detaileddescriptions of these systems can befound in Ref. [1].

The Condition Monitoring and Evalua-tion System is an on-line system withautomatic sampling of all “normal” en-gine performance data, supplementedby cylinder pressure measurements,utilising our CoCoS-EDS system. When

the data-evaluation system indicatesnormal running conditions, the sys-tem will not interfere with the normalpre-determined optimal operatingmodes. However, if the analysisshows that the engine is in a generallyunsatisfactory condition, generalcountermeasures will be initiated forthe engine as a unit. For instance, ifthe exhaust gas temperature is toohigh, fuel injection may be retardedand/or the exhaust valves may beopened earlier, giving more energy tothe turbocharger, thus increasing theamount of air and reducing the exhaustgas temperature.

At all events, the system reports theunsatisfactory condition to the operatortogether with a fault diagnosis, a speci-fication of the countermeasures usedor proposed, and recommendations forthe operation of the engine until normalconditions can be re-established or re-pairs can be carried out.

The 4T50MX research engine in ourR&D Centre in Copenhagen was op-erated from 1993 to 1997 with thefirst-generation Intelligent Engine (IE)system. The engine has been runningwith this system for the IE develop-ment as well as for its normal func-tion as a tool for our general engine

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mode reversing / crash stopEngine protection Optimal

Emission controlled mode

Fuel economy mode

OperatingMode Control

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Fig. 1: The Intelligent Engine concept

development. The 1990 runninghours logged during that period oftime has provided us with significantexperience with this system.

Being the first generation of IE, the sys-tem was somewhat ‘over-engineered’and relatively costly compared with thecontemporary camshaft system. Onthe other hand, the system offered muchgreater flexibility, which has provedits value in the use of the researchengine as one of our most importantdevelopment tools.

In 1997, the engine was fitted withsecond-generation IE systems, pleaserefer to Fig. 2 showing the fuel injectionand exhaust valve actuating systemson the engine. The second-generationsystems, to be described in more detailin the following, have been developedin order to:

• simplify the systems and tailor themto the requirements of the engine

• facilitate production and reduce thecosts of the IE system

• simplify installation and avoid the useof special systems wherever possible.

On the electronic software/hardwareside, the original first-generation sys-tem was used for a start. Since then,significant development efforts havebeen invested in transforming theelectronic part of the IE system into amodular system, where some of theindividual modules can also be used inconventional engines. This means de-velopment of a new computer unit andlarge software packages – both ofwhich have to comply with the demandsof the Classification Societies for ma-rine applications.

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Fig. 2: Second-generation ‘Intelligent Engine’ system fitted to the 4T50MX research engine in 1997

Design Features of theSecond-Generation IE System

General description

The principle layout of the new system,replacing the camshaft system of theconventional engine, is illustrated inFig. 3. The system comprises an engine-driven high-pressure servo oil system,which provides the power for the hy-draulically operated fuel injection andexhaust valve actuation units on eachcylinder. Before the engine is started,the hydraulic power system (or servooil system) is pressurised by means ofa small electrically driven high-pressurepump.

Furthermore, the starting air systemand the cylinder lubrication systemhave been changed compared withthe conventional engine series. A

redundant computer system controlsall these units.

The following description will outline themain features of these systems, togetherwith our recent development work andexperience.

Power supply system

Engine-driven multi-piston pumps sup-ply high-pressure lube oil to provide thenecessary power for fuel injection andexhaust valve actuation and thus re-place the camshaft power-wise. Themulti-piston pumps are conventional,mass-produced axial piston pumpswith proven reliability.

The use of engine system oil as the ac-tivating medium means that a separatehydraulic oil system is not needed, thusextra tanks, coolers, supply pumps anda lot of piping etc. can be dispensed

with. However, generally the enginesystem oil is not clean enough for directuse in high-pressure hydraulic systems,and it might be feared that the required6 µm filter would block up quickly.

We have undertaken quite extensivedevelopment work in collaboration witha filter supplier (B&K) in order to ensurethe cleanliness required for such sys-tems – the very positive long-term re-sults are described below.

Against this background, and based onthe fact that the clean lube oil from theengine was at least as suitable for usein the hydraulic system as conventionalhydraulic oil, we decided to base oursystem on fine-filtered system lube oil.This is supplied from the normalsystem oil pumps, providing a higherinlet pressure to the high-pressurepumps than otherwise – this being yetanother benefit.

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Fuel injection system,design features

The general design of the system isshown in Fig. 4. A common rail servo oilsystem using pressurised cool, clean lubeoil as the working medium drives the fuelinjection pump. Each cylinder unit isprovided with a servo oil accumulator toensure sufficiently fast delivery of servooil in accordance with the requirementsof the injection system and in order toavoid heavy pressure oscillations in theassociated servo oil pipe system.

The movement of the plunger is controlledby a fast-acting proportional control valve(a so-called NC valve), developed byour cooperation partner Curtiss WrightDrive Technology GmbH (formerly knownas SIG Antriebstechnik) of Switzerland.The NC valve is, in turn, controlled byan electric linear motor that gets its con-trol input from the cylinder control unit(see below).

This design concept has been chosenin order to maximise reliability and func-tionality – after all, the fuel injection sys-tem is the heart of the engine, and itsperformance is crucial for fuel economy,

emissions and general engine perfor-mance. An example of the flexibility ofthe fuel injection system will be givenbelow.

The key components have a proven reli-ability record: the NC valves have beenin serial production for some ten yearsand are based on high-performancevalves for such purposes as machinetools and sheet metal machines in carproduction – applications where highreliability is crucial. The fuel injectionpump features well-proven fuel injectionequipment technology, and the fuelvalves are of our well-proven and simplestandard design.

As can be seen in Fig. 5, the 2nd and3rd generations of pump design aresubstantially simpler than the 1st gen-eration design, the components aresmaller, and they are very easy to man-ufacture. By mid-2000, the 2nd gener-ation pump had been in operation onthe 4T50MX research engine for morethan 1400 hours, whereas the 3rd gen-eration is starting service testing on the6L60MC (see below).

The major new design feature for the3rd generation pump is its ability tooperate on heavy fuel oil. The pumpplunger is equipped with a modifiedumbrella design to prevent heavy fuel

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Fig. 4: General system layout for fuel injection and exhaust valve actuation systems

Fig. 5: Design development of fuel injection pumps

oil from entering the lube oil system.The driving piston and the injectionplunger are simple and are kept in con-tact by the fuel pressure acting on theplunger, and the hydraulic oil pressureacting on the driving piston. The begin-ning and end of the plunger stroke areboth controlled solely by the fast actinghydraulic valve (NC valve), which iscomputer controlled.

Fuel injection system, rate shapingcapability

The optimum combustion (thus alsothe optimum thermal efficiency) re-quires an optimised fuel injection pat-tern which is generated by the fuelinjection cam shape in a conventionalengine. Large two-stroke engines aredesigned for a specified max. firingpressure, and the fuel injection timingis controlled so as to reach that firingpressure with the given fuel injectionsystem (cams, pumps, injection nozzles,etc.).

For modern engines, the optimum in-jection duration is around 18-20 de-grees crank angle at full load, and themax. firing pressure is reached in thesecond half of that period. In order toobtain the best thermal efficiency, fuelto be injected after reaching the max.firing pressure must be injected (andburnt) as quickly as possible in order toobtain the highest expansion ratio forthat part of the heat released.

From this it can be deduced that theoptimum ‘rate shaping’ of the fuelinjection is one showing increasinginjection rate towards the end of injec-tion, thus supplying the remaining fuelas quickly as possible. This has beenproven over many years of fuel injectionsystem development for our two-strokemarine diesel engines, and the con-temporary camshaft is designed ac-cordingly. The fuel injection system forthe Intelligent Engine is designed to dothe same but in contrast to the cam-shaft-based injection system, the IEsystem can be optimised at a largenumber of load conditions.

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Fig. 6: Comparison between the fuel injection characteristics of the ME engine and aStaged Common Rail system in terms of injection pressure, mass flow rate and flowdistribution

Common Rail injection systems withon/off control valves are becomingstandard in many modern diesel en-gines at present. Such systems arerelatively simple and will provide largerflexibility than the contemporary cam-shaft based injection systems. We doapply such systems for controlling thehigh-pressure gas-injection in thedual-fuel version of our MC engines,where the (two-circuit) common railsystem provides the necessary flexibil-ity to allow for varying HFO/gas-ratios,please refer to [3].

However, by nature the common railsystem provides another rate shapingthan what is optimum for the enginecombustion process. The pressure inthe rail will be at the set-pressure at thestart of injection and will decrease dur-ing injection because the flow out of

the rail (to the fuel injectors) is muchfaster than the supply of fuel into therail (from high-pressure pumps supply-ing the average fuel flow).

As an example, an 8-cylinder enginewill have a total ‘injection duration’ perengine revolution of 160 deg. CA (8 x20 degrees CA) during which the injec-tors supply the same mass flow as thehigh-pressure supply pumps do during360 deg. CA. Thus, the outflow duringinjection is some 360/160 = 2.25 timesthe inflow during the same period oftime. Consequently, the rail pressuremust drop during injection, which is theopposite of the optimum rate shape.To counteract this, it has been pro-posed to used ‘Staged Common Rail’whereby the fuel flow during the initial

injection period is reduced by openingthe fuel valves one by one.

The Rate Shaping with the IE system(using proportional control valves) andthe ‘Staged Common Rail’ are illus-trated in Fig. 6. This shows the injec-tion pressure, the mass flow and thetotal mass injected for each fuel valveby the two systems, calculated bymeans of our advanced dynamic fuelinjection simulation computer codefor a large bore engine (K98MC) withthree fuel valves per cylinder. In thediagram, the IE system is designatedME (this being the engine designation,like 7S60ME-C). As can be seen, theStaged Common Rail system suppliesa significantly different injection amountto each of the three fuel valves.

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Fig. 7: Fuel spray distribution in the combus-tion chamber (schematically) correspondingto the injection patterns illustrated in Fig. 6

Fig. 8: Four examples of fuel injection pressures at the fuel valve, and the correspondingfuel valve spindle lifting curves

Though the Staged Common Rail sys-tem will provide a fuel injection rateclose to the optimum injection rate,combustion will not be optimal becausethe fuel is very unevenly distributed inthe combustion chamber whereas thecombustion air is evenly distributed.This is illustrated (somewhat over-exaggerated to underline the point)in Fig. 7: the valve opening first willinject the largest amount of fuel andthis will penetrate too much andreach the next fuel valve nozzle.Experience from older engine typesindicates that this may cause a reli-ability problem with the fuel nozzles(hot corrosion of the nozzle tip).

The uneven fuel injection amount meansthat there will be insufficient air for thefuel from the first nozzle, the correct

amount for the next and too much airfor the third fuel valve. The averagemay be correct but the result cannotbe optimal for thermal efficiency andemissions. Uneven heat load on thecombustion chamber components canalso be foreseen - though changing thetask of injecting first among the threevalves may ameliorate this.

Thus, the IE injection system is superiorto any Common Rail system – be itstaged or simple. Extensive testing hasfully confirmed that the IE fuel injectionsystem can perform any sensible injec-tion pattern needed for operating thediesel engine. The system can performas a single-injection system as wellas a pre-injection system with a highdegree of freedom to modulate theinjection in terms of injection rate,

timing, duration, pressure, single/dou-ble injection, etc.

In practical terms, a number of injectionpatterns will be stored in the computerand selected by the control system soas to operate the engine with optimalinjection characteristics from dead slowto overload, as well as during asternrunning and crash stop. Change-overfrom one to another of the stored injec-tion characteristics may be effectedfrom one injection cycle to the next.

Some examples of the capability of thefuel injection system are shown inFig. 8. For each of the four injectionpatterns, the pressure in the fuelvalve and the needle-lifting curve areshown. Tests on the research enginewith such patterns (see Fig. 9) have

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Fig. 9: Effect of injection pattern on combustion rate, NOx emission and specific fuel oil consumption(test on 4T50MX research engine at 75% load)

confirmed that the ‘progressive injection’type (which corresponds to the injec-tion pattern with our optimised cam-shaft driven injection system) issuperior in terms of fuel consumption.The ‘double injection’ type gives slightlyhigher fuel consumption, but some20% lower NOx emission – with a veryattractive trade-off between NOx re-duction and SFOC increase.

Exhaust valve actuation system

The exhaust valve is driven by the sameservo oil system as that for the fuel injec-tion system, using pressurised cool,clean lube oil as the working medium.However, the necessary functionality ofthe exhaust valve comprises only controlof the timing of opening and closing the

valve. This can be obtained by using asimple fast-acting on/off control valve.

The system features well-proven tech-nology from the present engine series.The actuator for the exhaust valve sys-tem is of a simple two-stage design,please refer to Fig. 10. The first-stageactuator piston is equipped with a col-lar for damping in both directions ofmovement. The second-stage actuatorpiston has no damper of its own, and isin direct contact with a gear oil pistontransforming the hydraulic system oilpressure into oil pressure in the oilpush rod. The gear oil piston includesa damper collar that becomes activeat the end of the opening sequence,when the exhaust valve movement willbe stopped by the standard air spring.

Control system

Redundant computers connected in anetwork provide the control functionsof the camshaft (timing and rate shap-ing) - please refer to Fig. 11. This newEngine Control System (see also [2]) isan integrated part of the IntelligentEngine that brings completely newcharacteristics to the engine. It com-prises two Engine Control Units (ECU),a Cylinder Control Unit (CCU) for eachcylinder, a Local Control Terminal andan interface for an external ApplicationControl System. The ECU and the CCUhave both been developed as dedicatedcontrollers, optimised for the specificneeds of the intelligent engine.

The Engine Control Unit controls func-tions related to the overall condition of

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the engine. It is connected to the PlantControl System, the Safety System andthe Supervision & Alarm System, and isdirectly connected to sensors and ac-tuators. The function of the ECU is tocontrol the action of the following com-ponents and systems:

• The engine speed in accordancewith a reference value from the appli-cation control system (i.e. an inte-grated governor control)

• Engine protection (overload protec-tion as well as faults)

• Optimisation of combustion to suitthe running condition

• Start, stop and reversing sequencingof the engine

• Hydraulic (servo) oil supply (lube oil)

• Auxiliary blowers and turbocharging.

The Cylinder Control Unit is connectedto all the functional components to be

controlled on each cylinder. Its functionis to control the activation of features like:

• Fuel injection

• Exhaust valve

• Starting valve

• Cylinder lubricator for the specificcylinder.

As faults can never be completely ruledout, even with the best design of elec-tronic (or mechanical) components, theconcept for the intelligent engine hasbeen designed with great care regard-ing fault tolerance and easy repair, toensure the continuous operation of theship. Since each cylinder is equippedwith its own controller (the CCU), theworst consequence of a CCU failure isa temporary loss of power from thatparticular cylinder (similar to, for in-stance, a sticking fuel pump on a con-ventional engine). The engine controller(ECU) has a second ECU as a hotstand-by which, in the event of a failure,

immediately takes over and continuesthe operation without any change inperformance (except for the decreasedtolerance for further faults until repairhas been completed).

In the event of a failure in a controller,the system will identify the faulty unit,which is simply to be replaced with aspare. As soon as the spare is con-nected, it will automatically be config-ured to the functions it is to replace,and resume operation. As both theECU and the CCU are implemented inthe same type of hardware, only a fewidentical spares are needed. If failuresoccur in connected equipment – sensors,actuators, wires, etc. – the system willlocate the area of the failure and,through built-in guidance and testfacilities, assist the engine operatingstaff in the final identification of thefailed component.

Cylinder pressure measuring system(PMI)

A reliable measurement of the cylinderpressure is essential for ensuring ‘asnew’ engine performance. A conven-tional mechanical indicator in the handsof a skilled and dedicated crewmembercan provide reasonable data. However,the necessary process is quite time-consuming and the cylinder pressuredata obtained in this way is not availablefor analysis in a computer, which meansthat some valuable information is lesslikely to be utilised in a further analysisof the engine condition. A computerisedmeasuring system with a high qualitypressure pick-up connected to the in-dicator bore may provide this. We havedeveloped such a system, PMI Off-Line,of which more than 100 sets havebeen sold for application on our con-ventional engines.

For the Intelligent Engine, on-line mea-surements of the cylinder pressure arenecessary – or at least greatly desirable.In this case, the indicator cock cannotbe used since the indicator bore willclog up after a few days of normaloperation, making further measure-ments useless.

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Fig. 11: Control system for the Intelligent Engine

Since we realised this quite some timeago, we have been working on the de-velopment of a reliable system for long-term continuous cylinder pressuremeasurements. The first, successful,attempt involved the use of straingauges on two cover studs on eachcylinder, thus in fact using the cylindercover itself as a ‘pressure transducer’.A long-term test was carried out on themain engine of a Danish ferry about tenyears ago, and the system provided uswith stable measurements over a pe-riod of more than 10,000 operatinghours.

However, there was some electricalnoise in the signals, and we decided touse another system that had been intro-duced on the market in the meantime:the strain-pin type of pressure sensor.The pressure-sensing element is a rodlocated in a bottom-hole in the cylindercover, in close contact with the bottomof the hole, close to the combustionchamber surface of the cylinder cover,as can be seen in Fig. 12. Thus, thesensor measures the deformation of thecylinder cover caused by the cylinderpressure without being in contact withthe aggressive combustion productsand without having any indicator borethat can clog up. The position of thesensor also makes it easier to preventelectrical noise from interfering with thecylinder pressure signal.

The pressure transducer of the off-linesystem is used for taking simultaneousmeasurements for calibrating theon-line system. By feeding the two sig-nals into the computer in the calibrationmode, a calibration curve is determinedfor each cylinder. The fact that thesame, high-quality, pressure transducer

is used to calibrate all cylinders meansthat the cylinder-to-cylinder balance isnot at all influenced by differences be-tween the individual pressure sensors.

The on-line as well as the off-linesystem provide the user with uniqueassistance for keeping the engineperformance up to ‘as new’ standardand reduce the workload of the crew.The systems automatically identifythe cylinder being measured withoutany interaction from the person car-rying out the measurement (becausethe system contains data for the en-gine’s firing order). Furthermore,compensation for the crankshafttwisting is automatic, utilising propri-etary data for the engine design. Ifthere is no such compensation, themean indicated pressure will be mea-sured wrongly and when it is used toadjust the fuel pumps, the cylinderswill not have the same true uniformload after the adjustment although itmay seem so. Twisting of the crank-shaft may lead to errors in mean indi-cated pressure of some 5% if notcompensated for!

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Fig. 12: PMI on-line cylinder pressure sensor of the strain-pin type, built into the cylindercover, without contact with the corrosive combustion gases

Fig. 13: Example of PMI system output: cylinder balance table with recommendedadjustments

The computer carries out the tediousand time-consuming work of evaluatingthe ‘indicator card’ data which are nowin computer files, and the cylinderpressure data can be transferreddirectly to our CoCoS-EDS EngineDiagnosis System for inclusion in thegeneral engine performance monitoring.Furthermore, the result presented tothe crew is far more comprehensiveand comprises a list of the necessaryadjustments, as illustrated in Fig. 13.These recommendations take intoaccount that the condition of thenon-adjusted cylinders changes whenthe adjustments are carried out. So itis not necessary to check the cylinderpressure after the adjustment.

Electronic cylinder lubricator

The concept of the new electronic cyl-inder lubricator is illustrated in Fig. 14.A pump station delivers lube oil to thelubricators at 45 bar pressure. Thelubricators have a small piston for eachlube oil quill in the cylinder liner, andthe power for injecting the oil comesfrom the 45 bar system pressure, act-ing on a larger common driving pistonas shown in Fig. 15. Thus, the drivingside is a conventional common railsystem, whereas the injection side is ahigh-pressure positive displacementsystem, thus giving equal amounts oflube oil to each quill and the best pos-sible safety margin against clogging ofsingle lube oil quills.

For the large bore engines, each cylinderhas two lubricators (each serving half ofthe lube oil quills) and an accumulator,while the small bore engines (withfewer lube oil quills per cylinder) areserved by one lubricator per cylinder.The pump station includes two pumps(one operating, the other on stand-bywith automatic start up), a filter andcoolers.

The lubricator can be delivered for ourconventional engines in which case it iscontrolled by a separate computer unitcomprising a main computer, control-ling the normal operation, a switchoverunit and a (simple) back-up unit. A shaftencoder (which can be shared with a

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Fig. 14: System design of the electronic cylinder lubricator

Fig. 15: Cylinder lubricator unit, controlled by the computer and driven by 45 bar lube oilpressure

PMI system) supplies the necessarytiming signal in that case. When usedon ‘Intelligent Engines’, these func-tions are integrated in the enginecontrol computers and their shaftencoders.

The lubrication concept is intermittentlubrication – a relatively large amountof lube oil is injected for every four(or five or six, etc.) revolutions, theactual sequence being determined bythe desired dosage in g/bhph. Theinjection timing is controlled preciselyand – by virtue of the high deliverypressure – the lube oil is injected exactlywhen the piston ring pack is passingthe lube oil quills, thus ensuring thebest possible utilisation of the costlylube oil. This is illustrated in Fig. 16.

The control computers have passedthe necessary tests (E10), and the finalapproval by a number of ClassificationSocieties took place in Copenhagen inApril 2000, paving the way for large-scale commercial deliveries. Productionof the electronic hardware has startedand the first commercial units are inservice on K90MC/MC-C/MC-S andS90MC-C engines.

Prior to that, the system was tested inoperation on a 7S35MC for more thantwo years with good results, and tests ona cylinder of a K90MC engine over some12,000 service hours have given very sat-isfactory results, with low lube oil dosage(for more details, please see [4]).

. On the IntelligentEngine, the pneumatic control systemfor the starting air valves has been re-placed by an electronically controlledsystem with solenoid valves on thestarting air valves, offering greater free-dom and more precise control. The‘slow turning’ function is maintained.

Advantages of the IntelligentEngine Concept

The electronic control of the fuel injec-tion system and the exhaust valve op-eration means a number of advantagesthat are briefly listed below, categor-ised in three main groups.

Reduced fuel consumption:

• fuel injection characteristics can beoptimised at many different load

conditions whereas a conventionalengine is optimised for the guaranteeload, typically at 90-100% MCR

• constant pmax in the upper loadrange can be achieved by a combi-nation of fuel injection timing andvariation of the compression ratio(the latter by varying the closing ofthe exhaust valve). As a result, themax. pressure can be kept constantover a wider load range without over-loading the engine, leading to signifi-cant SFOC reductions at part load

• the on-line monitoring of the cylinderprocess ensures that the load distri-bution among the cylinders and theindividual cylinder’s firing pressurecan be kept up to ‘as new’ standard,maintaining the ‘as new’ performanceover the lifetime of the engine.

Operational safety and flexibility:

• the engine’s crash stop and reverserunning performance is improvedbecause the timing of exhaust valvesand fuel injection can be optimal forthese situations too

• ‘engine braking’ may be obtained,reducing the stopping distance ofthe vessel

• faster acceleration of the engine be-cause the scavenge air pressure canbe increased faster than normal byopening the exhaust valve earlierduring acceleration

• dead slow running is improvedsignificantly: the minimum r/min issignificantly lower than for a conven-tional engine, dead slow running ismuch more regular, and combus-tion is improved thanks to theelectronic control of fuel injection

• the electronic monitoring of the engine(based on our CoCoS-EDS system)identifies running conditions whichcould lead to performance problems.Damage due to poor-ignition-qualityfuel can be prevented by fuel injectioncontrol (pre-injection)

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Fig. 16: Pressure measured in cylinder lubricating oil quills, and timing of lube oil injection

• the engine control system includesour on-line OPS-feature: OverloadProtection System, which ensuresthat the engine complies with theload-diagram and is not overloaded(as is often seen in shallow watersand with ‘heavy propeller’ operation)

• maintenance costs will be lower(and maintenance easier) as a resultof the protection against generaloverloading as well as overloading ofsingle cylinders, and the ‘as new’running conditions for the engine,which is further enhanced by theability of the engine diagnosis systemto give early warning of faults, thusenabling proper countermeasures tobe taken in due time.

Flexibility regarding exhaust gasemissions:

• the engine can change over tovarious ‘low emission modes’ whereits NOx exhaust emission can bereduced below the IMO limits ifdesirable due to ‘local’ emissionregulations

• by suitable selection of operatingmodes, the vessels may sail withlower exhaust gas emission within‘special areas’ where this may berequired (or be economical due tospecial harbour fee schemes) with-out having negative effects on theSFC outside such special areas.

Service Experience with theIntelligent Engine

The world’s first Intelligent Engine inservice as the main propulsion enginefor a merchant vessel is the 6L60MCof the chemical product carrier M/TBow Cecil, which was delivered inOctober 1998 to the Norwegian ownerOdfjell ASA by the Kværner Florø Yardin Norway.

Design of IE systems for M/T BowCecil

The engine was prepared for the IEsystems during its production. The me-chanical/hydraulic components of theIE systems were fitted to the engineduring its installation in the vessel at theyard. These systems are installed onthe upper platform of the engine, inparallel with the conventional camshaft,as shown in Fig. 17.

With this set-up, it is possible tochange over completely from the con-ventional system to the IE system, orvice versa, within some three hours, sothere is full redundancy. Fig. 18 is aphoto taken at the yard in 1998, show-ing the installation of the IE systems onthe upper platform of the engine.

The power for operating the fuel injec-tion system and the exhaust valves issupplied by a hydraulic powerpack.This comprises high-pressure axial pis-ton pumps, driven by the engine (seeFig. 19), together with electrically drivenpumps, supplying oil pressure prior tostarting the engine and controlling theoil flow during its operation. The workingmedium is fine filtered engine system oil,as described in detail below.

Service experience with IE systemson M/T Bow Cecil

The ordinary camshaft system was usedon the sea trial in accordance with theoriginal contract between the parties, andit has also been used during the first op-erating period of the vessel. During thistime, the auxiliary systems have beenput in operation and tested thoroughly.The following has been experienced

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Fig. 17: Installation of the IE fuel injection and exhaust valve control systems in parallel withthe conventional camshaft of the 6L60MC main engine of M/T Bow Cecil

Fuel injec-tion pump

with these systems prior to the opera-tion as a complete ‘Intelligent Engine’:

Hydraulic oil conditioning system.The power medium employed for oper-ating the fuel injection pumps and theexhaust valves is fine-filtered systemoil from the engine, thus avoiding aseparate hydraulic oil system withtanks, pumps, coolers, etc. The driv-ing system utilises lube oil at a moder-ate working pressure (160–200 bar),but even so it is essential for ensuring along lifetime of such hydraulic systemsthat the oil is clean, which requires ISOx/16/13.

However, the requirements for the en-gine system oil are not that strict – norare they needed for the engine itself;therefore, the oil for the IE systemsrequires extra filtration. For this purposewe use an automatic 6-micron filterlocated in the supply line to the IEsystem from the main lube oil pipe ofthe engine. From a system point ofview, this acts as by-pass filtration andthus, over time, will fine-filter the wholeoil charge of the engine – obviously withthe risk of clogging the filter.

Before deciding to use this system, wehad tested it on our 4T50MX researchengine with good results, confirmingthat filter clogging was not a problemand that the higher inlet pressure sup-plied to the hydraulic power supply unit(engine-driven axial piston pumps) wasindeed an advantage for these pumps.

Subsequently, the filter system was fit-ted to a sister vessel to M/T Bow Ceciland service tested over a period of oneyear. The results were very satisfactory,again confirming that filter clogging wasnot a problem and that also the wholeoil charge of the engine became signifi-cantly cleaner than before – an addedbenefit for the engine.

The fine-filtering system has also beenin operation on M/T Bow Cecil eversince the sea trial. The ‘commissioning’of the filter during the sea trial is illus-trated in Fig. 20. The first operatinghours during a sea trial must be expec-ted to deliver rather high amounts of

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Fig. 18: Installation of IE system on the upper platfrom of the 6L60MC main engineof M/T Bow Cecil

Fig. 19: Engine driven high-pressure pumps on the front end of the 6L60MC engine

particles (i.e. a high filter load). However,it can be seen that back-flushing of thefilter is not triggered by the permissiblepressure drop across the filter (max.0.6 bar) being exceeded, but only bythe timer, which is set to backflushevery hour. The subsequent serviceexperience with the system has beenvery satisfactory – the only problemencountered was a ‘cold soldering’on the print card for the filter control,which has been rectified by the supplier.

On-line cylinder pressure measuringsystem PMI, and CoCoS-EDS.These two systems were installed onthe engine in August 1999 and are nowbeing used by the crew as normal toolsfor monitoring the engine. After someminor teething troubles onboard, thePMI system is working stable andreliably, providing on-line data on theworking of the cylinders to the CoCoSEngine Diagnosis System (EDS).

Electronic hardware and software.The development of the electroniccontrol systems for fuel injection andexhaust valve actuation was delayeddue to the complexity of the software.The hardware has passed the requiredtest (E10). Software approval is a

two-step procedure: first, a SW devel-opment audit must be performed bythe Classification Society in question(Det Norske Veritas). This has beendone, and we have been approved fordeveloping such software. The secondstep comprises a demonstration (onthe 4T50MX research engine) of thefunctionality of the SW in the actualHW, for the purpose of proving that thecomplete system works as describedin the design specification. This testwas performed to the full satisfaction ofDNV in September 2000.

The Mode Selection screen of the HMI(Human Machine Interface) is shown inFig. 21. Using this, the operator hasthe possibility to switch between theoperating modes for the engine (‘FuelEconomy’ and ‘Emission Control’), aswell as to switch between governorcontrol modes such as ‘ConstantSpeed’ and ‘Constant Torque’.

An overview of the engine status isavailable from the ‘Main Status Display’,as can be seen in Fig. 22. This shows(at the top) the actual mode for theengine, the governor and the hydraulicpower supply system. It indicates fromwhere control is taking place (the bridge

in the case shown here) together withindex status and the actual propellerpitch for the CP propeller.

Control of the hydraulic power supply.The control software for the hydraulicpower supply (engine and electricallydriven hydraulic pumps) has been final-ised and tested. The control systemwas successfully installed and testedon board M/T Bow Cecil in April 2000.

Full scale IE service tests on M/T BowCecil. After completion of the demon-stration of system functionality for DNV,the next step was to start actual opera-tion with the computer controlled fuelinjection and exhaust valve actuationsystems – the world’s first full scale‘Intelligent’ marine engine in service.

In consideration of the vessel’s serviceschedule, it was found feasible to startthis test with a ‘quay trial’ outside Ham-burg, Germany, on 1st-2nd October2000. During this trial, all systems weretested with very satisfactory results –including perfect dead slow operation at15 r/min.

The final step before the vessel resumedits schedule – now as an IntelligentEngine, i.e. without a camshaft – wasa sea trial wich was carried out in thepresence of surveyors from Det NorskeVeritas in order to have the final approvalfrom DNV and to maintain the vessel´scertificate.

This sea trial was carried out off Bor-neo on 7th and 8th November 2000.The final approval document from DNVstates: ‘All tests were passed and it isjudged that the engine and associatedsystems perform equally as good orbetter with the Intelligent Engine sys-tem in operation as with the traditionalcamshaft system’.

Thus, the end of the successful seatrial marked the beginning of thelong-term service test which will beconducted over a period of some10,000 operating hours to confirm theefficient and reliable operation of boththe IE systems and the engine proper.

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Fig. 20: Commissioning of fine-filter during the sea trial of M/T Bow Cecil

Commercialisation of theIE Concept

In 1999, two V-Max class ULCCs(Fig. 23) were ordered at HyundaiHeavy Industries in Korea for deliveryin first-half of 2001, each with two7S60ME-C engines, the ‘IntelligentEngine’ version of the well-estab-lished 7S60MC-C engine.

As a result of the previously mentioneddelays in the development of the con-trol software, and in order to ensurethat the vessels are delivered on time,it has been agreed to make provisionfor conventional operation during theinitial service period of the two vessels.The engines will be delivered preparedfor later conversion to the 7S60ME-Cversion and will have the PMI on-linecylinder pressure measuring system,the CoCoS-EDS engine diagnosis sys-tems, the CoCoS-MPS maintenanceplanning system and the electroniccylinder lubrication system in operationfrom the outset.

This will allow time to gain appropriateservice experience with M/T Bow Cecil.Subsequently, the engines will be con-verted to proper 7S60ME-C ‘Intelligent’engines during the scheduled dockingof the vessels. At that time, the con-ventional camshaft system will beremoved and replaced by the IE systems,which will utilise the existing camshafthousing as oil pan and foundation.

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Fig. 21: Mode Selection Display

Fig. 22: Main Status Display

Conclusion

To meet the increasingly diversifiedpropulsion requirements, MAN B&WDiesel has continuously introducedup-to-date engines to supplement thewell-known MC engine series. Hence ourcompany offers the most comprehensiveand versatile engine programme inthe market for virtually all commercialvessels, over the full range of sizes andtypes.

Environmental friendliness and impec-cable reliability will be the dominant de-velopment goals in the years to come.To meet these requirements at an ac-ceptable production cost, an increas-ing use of electronics is foreseen, andthe concept of the Intelligent Engine willbe applied in the marine engines of thefuture – just as has been seen in theautomotive engine field in recent years.

References

[1] P. Sunn Pedersen: “DevelopmentTowards the Intelligent Engine”,16th International Marine PropulsionConference, London 10-11 March1994, Proceedings pp 77-88

[2] P. Sørensen & P. Sunn Pedersen:“The Intelligent Engine and ElectronicProducts - A Development Status”.Proceedings of the 22nd CIMACInternational Congress on CombustionEngines, Copenhagen 18-21 May1998, pp 551-564

[3] ‘Utilisation of VOC in Shuttle Tankers’,MAN B&W Diesel A/S, companypublication P.342-98.11, 1998(25 pages)

[4] P. Sunn Pedersen & P. Sørensen:‘Computer Controlled System fortwo-stroke Machinery (A ProgressReport)’. 22nd Marine PropulsionConference, Amsterdam 29-30March 2000. Conference Proceed-ings, pp 17–33.

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S2000 V-Max

Main engines: 2 x 7S60ME-C

Fig. 23: S2000 V-Max shallow draught 314,500 dwt VLCC for Concordia Maritime (of the Swedish Stena Group)