Cylmate® Systems

– award winnerby Lars O Karlsson, M.Sc.Reprint from The Scandinavian Shipping Gazette, Yearbook of Maritime Technology 2005

THE SCANDINAVIAN SHIPPING GAZETTE • SEPTEMBER 23, 2005 43

SCANDINAVIAN YEARBOOK OF MARITIME TECHNOLOGY 2005

By Lars Karlsson, ABB Automation Technologies AB,lars.o.karlsson@se.abb.com

� IN JUNE 2004 at the 24th Cimac Con-gress in Kyoto, Japan, ABB’s paper on

Cylmate Systems (see reference below) washonored with the CIMAC President’sAward for 2004, a very prestigious award inthe engine industry. The motivation was:“The award was given on a basis of a practi-cal contribution to the future success ofthe engine industry”.

In the present report we outline someexamples presented in the Cimac paperand we also show some further improve-ments on Cylmate that recently have beenreleased. These new features will be veryuseful tools, not only for online analysis bythe crew onboard, but also for offlineanalysis that can be performed at the homeoffice.

The objective of the Cimac paper was topresent long time continuously measureddiesel engine performance data for large 2-stroke diesel engines. The unique feature isthat every single stroke is measured and

Cylmate pressure transducers makes it possible to constantlymeasure the combustion pressure in large two-stroke engines.

CylmateSystems – award winner

used in the data evaluation. It was shownhow this feature makes is possible to iden-tify errors in the engine at a very earlystage, and to follow up the running condi-tions of the engine.

Long time continuouslymeasured data

The longest period of time with continu-ously measured data presented is fromM/V Anna Maersk. The data covers 81 daysof operation from June 7 to August 26,2003, where approximately 7.3 millionstrokes per cylinder were measured andused in the analysis. Anna Maersk is a largecontainer vessel with a Wärtsilä NSD12RTA96C engine.

In Figure 1, the engine speed, pmax andMIP as a function of time, are shown,where also the route and some of the portsare indicated.

150 million strokes

M/V Maersk Arun is a container vessel witha MAN B&W 7S50MC engine. Cylmatewas installed in spring 2001 on Maersk

Arun and it was the second Cylmate instal-lation. Three of the pressure transducers onMaersk Arun are early prototypes and havebeen in continuous operation since theinstallation in year 2001 without any cool-ing, maintenance or recalibration. Thenumber of strokes measured with thesespecific transducers are approximately 150millions per transducer.

The Cylmate pressure transducer is

2004 CIMAC President’s award.

Figure 1. 7.3 million strokes per cylinder measured during 81 days.

Cylmate pressure transducer. Cut throughview after two years of operation withoutany sign of clogging (left). Installationexample (right).

Reference:Karlsson, L and Sobel, J: “Stroke by strokemeasurement of diesel engine performance onboard”, Paper 23 presented at the 24th CimacCongress in Kyoto, Japan, June 7–11, 2004.

44 THE SCANDINAVIAN SHIPPING GAZETTE • SEPTEMBER 23, 2005

mounted close to the cylinder cover at theindicator bore. It has a blow-throughdesign that gives easy cleaning as the indi-cator valve is mounted on the top of thetransducer. The transducers are operatingwithout any cooling.

Detection of a fault inthe cooling of a fuel valve

M/V Malmö Link is a ro-pax ferry with twoSulzer 6RND68M engines. On the portengine of this vessel, the first Cylmate sys-tem was installed early in year 2001. Oneyear later, the starboard engine was alsoequipped with Cylmate.

Malmö Link identified a problem withcylinder 5 on starboard engine. For allloads, except full load, the pressure was sig-nificantly lower than on the other cylin-ders. Initially, the crew changed the fuelvalve, but the problem came back after sev-en to eight hours.

In Figure 2 trend data for a nine hourtrip between Travemünde and Malmö isshown using the Cylmate Operator Sta-tion. The data displayed is engine speedand pmax for cylinders 4, 5 and 6.

With a non-continuous measuring sys-tem, you perform measurements at nomi-nal load, making it impossible to see andanalyse this problem, which only appearedat low load.

However, in this case the crew estab-lished the cause to be a blocked water cool-ing tube, due to a stretched screen cover,see Figure 3. This made the fuel valveneedle stick when it was fully open, andtherefore too much fuel was injected inrelation to the air from the turbocharger,which caused incomplete combustion. Theconsequences if they did not solve theproblem should have been more air-pollu-tion and an increased fuel consumption.

Early detection of faulty exhaust valve

M/V Hanjin Ottawa is a large container ves-sel with a Wärtsilä NSD 10RTA96Cengine.

The pressure at Top Dead Center(TDC) of cylinder 5 was slightly lowerthan the other, especially noticeable atlow rpm and low scavenging air pressure,see Figure 4 (left-hand side). The data dis-played is engine speed (blue curve) andpTDC for cylinders 1, 2 and 5 (green, brownand red curves).

After the change of exhaust valves oncylinder 5, the pressure at TDC came backto normal, see Figure 4 (right-hand side).“Malmö Link”

THE SCANDINAVIAN SHIPPING GAZETTE • SEPTEMBER 23, 2005 45

SCANDINAVIAN YEARBOOK OF MARITIME TECHNOLOGY 2005

The reason for the problem was that theclosing of the exhaust valve was degenerat-ed by a leaking air spring.

Stroke-by-stroke engineperformance analysis

In Figure 5, the engine speed for HanjinOttawa is shown for the first part of a voy-age between Yantian and Kaohsiung. Thefirst part of the plot shows the vesselmaneuvering out of Yantian, then speedwas gradually increasing. After 40 minutes,the fuel was switched off, the vessel wentdown in speed, and then after some min-utes the speed was increased again.

The MIP values for each of the ten cylin-ders are shown in Figure 5. The MIP valuesare strongly influenced by any error in theTDC location.

The thermodynamic TDC, computedfrom the pressure curve for each cylinder,is shown versus time in Figure 5, and is invery good agreement with the expectedbehavior as they slightly increases whenthe engine is getting warmer and that thethermodynamic TDC reach a value ofapproximately –0.1 degrees crank angle.

The conclusion is that the crank-shaftdeformation model of Cylmate predictsthe thermodynamic TDC of each cylinderin a very proper way, and thus the accuracyin the calculated MIP values is very high.Further, one can conclude that advanced

engine analysis is possible on a stroke bystroke basis even under dynamic load con-ditions.

Follow-up of running conditions

When analyzing data from M/V AxelMaersk, a sister vessel of the previous men-tioned Anna Maersk, a change in the com-bustion process around June 20, 2003 was

identified. It was later confirmed by thecrew that a change of fuel with a followingadjustment of the fuel quality settings hadtaken place at that time. In Figure 6, pre-senting the average angle of maximum pres-sure versus Fuel Index, the influence of thechange in the combustion process is clearlyseen. The change of fuel did not influenceaverage MIP and pmax, as seen in Figure 7.

Figure 2. Trend picture from “Malmö Link”.

Figure 4. Before and after change of exhaust valves.

Figure 5. Engine speed, MIP and thermodynamic TDC.

Figure 3. Blocked water cooling tube.

46 THE SCANDINAVIAN SHIPPING GAZETTE • SEPTEMBER 23, 2005

SCANDINAVIAN YEARBOOK OF MARITIME TECHNOLOGY 2005

New function – Cylmate Viewer

The “Performance history – reference”report is a powerful tool for recordingengine status and behavior at different loadand environmental conditions. As soon asthe engineer needs it, he can store a record

with live date from 68 consecutive strokes.For example a recording can be taken dur-ing the sea trial, at tropical conditions, atNordic sea conditions, after engine over-haul and so on. Each recording is stored onthe hard disk and can be used as referencevalue for future comparisons.

This report function can also be used torecord any performance deviation fromnormal behavior. The file with the record-ed strokes can be used for later off-lineanalysis on board or it can be sent to thehome office for expert analysis.

The analysis is done by means of a free-standing tool, the “Cylmate Viewer”. TheViewer works like a video player. It canplay the recorded stroke sequence. Thestrokes can be replayed from stroke 1 tostroke 68 – forward or backward. TheViewer will for each stroke show the pres-sure curves, crank angles, trends, devia-tions, scavenging air pressure, pmax, pcomp,etc.

The “Performance history – alarm”report is an indispensable tool for enginefault analysis. As soon as Cylmate hasdetected an engine combustion alarm arecord of 68 strokes will automatically bestored. The stored file will include all com-bustion data for 60 strokes before thealarm, data for the actual stroke at whichthe fault was detected and data for sevenstrokes after the alarm stroke.

The fault analysis is done by means ofthe Cylmate Viewer. This is the first com-mercial tool on the market that has allinformation of the combustion processstroke by stroke – before the alarm, at thealarm, and after the alarm. That means it ispossible to see the development of a faultand to get understanding of the mecha-nism that led to the fault. Based on thisknowledge future alarms of this kind canbe avoided.

New function –engine performance report

The engine performance report can be seenas an engine logbook, which clearly sum-marizes all important combustion parame-

Figure 6. Average angle of pmax versus Fuel Index.

Figure 7. Average MIP versus fuel index and average pmax versus fuel index.

We have local representatives in:Argentina Buenos Aires, Australia Melbourne, Austria Vienna, Bahrain Manama, Benelux Luxembourg,Brazil São Paulo, Chile Santiago, China Beijing, Denmark Odense, Finland Helsinki, France Lyon, Germany Düsseldorf,India Bangalore, Indonesia Jakarta, Italy Milan, Japan Tokyo, Korea Seoul, Malaysia Kuala Lumpur,Mexico Guadalajara, Norway Oslo, Philippines Manila, South Africa Johannesburg, Spain Barcelona,Taiwan Kaohsiung, Thailand Bangkok, United Kingdom Manchester, USA/Canada Brewster N.Y., Venezuela Caracas

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ABB Automation Technologies ABForce MeasurementS-721 59 Västerås, SwedenPhone: +46 21 34 20 00Fax: +46 21 34 00 05Internet: www.abb.com/pressductor

SCANDINAVIAN YEARBOOK OF MARITIME TECHNOLOGY 2005

ters. The report can be printed, stored onthe hard disk, burned to a cd/dvd and/ortransmitted to a superior system.

Conclusion

The main conclusion of this paper is that itis now possible to measure, during a longperiod of time, the combustion pressurecontinuously on large two-stroke dieselengines. When measuring continuously itis possible to identify errors in the engineat a very early stage, and to follow up therunning conditions of the engine. Cylmate

pressure transducers, which have been incontinuous operation since the installationin year 2001, are still measuring accurately.Further, new functions in the Cylmate Sys-

tem make it possible to also analyse thecombustion process on a stroke by strokebasis off-line, for an example at the homeoffice. ¡

Cylmate engine performance report.

Cylmate Viewer.

Reprint from The Scandinavian Shipping Gazette, Yearbook of Maritime Technology 2005www.shipgaz.com

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