MAN B&W Service Experience 2013

1 < > MAN Diesel & Turbo 1

Athens 30th May 2013

MAN Diesel & Turbo

Service Experience

MAN B&W Two-Stroke Engines

All data provided in this document is non-binding.

This data serves informational purposes only and is

especially not guaranteed in any way. Depending on the

subsequent specific individual projects, the relevant

data may be subject to changes and will be assessed and

determined individually for each project. This will depend

on the particular characteristics of each individual project,

especially specific site and operational conditions.

Stig Baungaard Jakobsen

Head of Two-Stroke Operation

2 < > MAN Diesel & Turbo

Service Experience of

MAN B&W Low Speed Diesel Engines

Cold Corrosion in Cylinder Liners

Low-Load Operation an Update

Cylinder Oils and Cylinder Lubrication


<

6S50ME-B9.2: inspection

after sea trial

S50ME-B9.2:

Cold Corrosion Problem and Solution


<

S50ME-B9.2:

Cold Corrosion


<

M/V XXX, 6S50ME-B9.2,

Inspected Rotterdam 7th

October 2012 at 992

running hours

S50ME-B9.2:

Cold Corrosion


<

The S50ME-B9.2 initially had a too high corrosive level,

resulting in too high liner wear

Countermeasures:

Increase cooling water outlet temperature to 90 deg. C

(new standard for most new engines)

Modify liners by insulated cooling pipes

New liner with decreased cooling intensity is being designed

S50ME-B9.2:

Cold Corrosion


S50ME-B9.2

Cold Corrosion - Countermeasures

1. Increased cooling water temperature

2. Cooling pipes

a) Engines already built insulated cooling pipes

b) Future engines - modified hole pattern

9 < > MAN Diesel & Turbo MAN Diesel & Turbo SE

Cooling Water pipe

modifications

Controlling Corrosive Wear Modification by insulated pipes


<

Test set-up Final set-up

Manometer

Flow meter

Valve

Orifice Orifice

Orifice

Controlling Corrosive Wear Modification by simple cooling water bypass


Cylinder liner outlet

Cylinder liner inlet

Cylinder cover outlet

Cylinder cover inlet

Two new cooling

water main pipes

80 degrees

Variable

temperature:

Up to 120C

Cylinder liner

cooling jacket:

KF material

O-rings: Peroxide

cured

Controlling Corrosive Wear Design modifications, new G-engines


General Recommendations Service letter: SL09-511 Service letter: SL11-544 Inspection report template

Low Load Operation

Service Experience

< 3337930.2011.09.09 (LEO/SBJ)

14 < > MAN Diesel & Turbo < 14

>

Fatigue defect

on edge of the

oil wedge

K98 ME/MC & ME-C/MC-C

Crosshead bearings & TC-cutout


>

Exessive oil film pressure with minor

fatigue defect

occuring on the

edge of the oil

wedge




>




17

Oil film pressure [MPa] Oil film thickness [m]

Standard design

40o wide centre pad

Modified design

68o wide centre pad

Pressure reduced by

approx. 10%

High pressure close

to oil grooves

Lower pressure close

to oil grooves




>



Countermeasures (by MDT):

Investigate and design upgrated bearings

Make instructions for inspection and assessment of crosshead bearing condition (Circular Letter to owners has been issued)

Assist owners in assessment of bearing damages

Immidiate actions (by owners):

Continue low load operation with T/C cut-out

Maintain normal inspection of crankcase for white metal findings

Use of endoscope for additional inspection of bearing condition (as example during

dry docking to determine which bearing to open-up)

NOT necessary to open up bearings unless findings of white metal fall-out


<

Super Slow Steaming (SSS) Service Experience: Burn-Away on Exhaust Valve


<


This calls for more frequent inspection when

operating at low load continously


Burn-Away of Spindle Disc

Name/dept xxxxxxx.yyyy.mm.dd

S60MC-C8 Running hrs 26.000

Burn away: > 11 mm (max. 9 mm)

Low load operation with consequently higher

burn away rate of exhaust valve spindle disc:


Engine type Burn away Running

hrs.

Burn

away rate

Reduction in

lifetime of spindle

K98ME 9 mm. 14.000 0.64 35%

S60MC-C 11 mm. 26.000 0.43 35%

K98MC-C 7.5 mm. 15.000 0.50 15%

S90MC-C8 14 mm. 15.000 0.93 61%

Burn away rate = mm / 1000 hrs

Normal lifetime = 100.000 hrs. with two times reconditioning for above mentioned engines

Some of above information is received from owners and we have limited information of engine load




0 10 20 30 40 50 60 70 80 90 100 110

Tem

p

% Load

BOTTOM , normal operation

SEAT, normal operation

BOTTOM , T/C cut-out

SEAT , T/C cut-out

Influence of T/C Cut-out on Exhaust Valve Temperatures

- New Service Letter under Preparation



Influence of Aux Blower Operation on Exhaust Valve Temperatures

- New Service Letter under Preparation

25 10

Tem

p

% Load

BOTTOM, Aux Blower on

SEAT, Aux Blower on

BOTTOM, Aux Blower off

SEAT, Aux Blower off


Cylinder Oil specification for MAN

B&W engines:

Viscosity to be SAE50

Alkalinity design basis BN70

Low sulphur fuel operation: Low BN cylinder oil to be used, i.e. vessels to be equipped with

tanks for two cylinder oil grades.

The above guide lines have remained

unchanged for many years!

Cylinder Lubrication, Preventing Cold Corrosion

Standard Recommendations for MAN B&W Engines


High BN Low BN


Standard Recommendations for MAN B&W Engines


28

More Acid Corrosion (Cold Corrosion)

seen on newer part/low load fuel

optimised engines

Neutralisation: H2SO4 + CaCO3 = CaSO4

Internt teknik mde, 5. januar 2012, presented by Henrik Rolsted


New Challenges!


General layout strategy for new engine types in order to

fulfil Tier II and low part load SFOC:

Increased scavenging air pressure

Late closing of exhaust valve 2-stroke Miller timing

Adjustments of compression volume

Increased maximum combustion pressure


More Challenges due to New Layout Strategy



More Challenges due to new Layout Strategy


MAN Diesel & Turbo

Mk9 engines with WHR / EGB practising

super slow steaming, operating highly

corrosive with insufficient alkalinity

BN level in the used drain oil being close

to zero, why detergency level in the oil

become too small

The result becomes CaSO4 deposits on

ring-land and ring grooves

CaSO4 deposits


More Challenges due to new Layout Strategy

Therefore, high BN Cylinder Oil

is needed !


ACC lubrication, factor as function of BN variations:


Standard Lubricating Guide Lines for MAN B&W Engines


For engine types:

Mark 9 and further. E.g. S80ME-C9.

All G-engines.

We recommend to use Cylinder Lube Oil:

For High Sulphur Fuel: Cylinder lube oil with 70BN

or higher

For Low Sulphur Fuel: Cylinder lube oil with 40BN

or lower

Cylinder lube oil viscosity: SAE50


Standard Lubricating Guide Lines for MAN B&W Engines



Cylinder Oils for Mk9 Engines

New high BN cylinder oils are presently being

introduced, or under development:

BN100 from Lukoil

BN 80 from BP

BN 7X from maker A

BN 7Y from maker B

BN 8Z from maker C

BN 9W from maker D

Ask your oil supplier for high BN cylinder oil for part load

fuel optimised and Mk. 9 engines



New Cylinder Lubrication Update, New Service Letter



New Service Letter, Feed Rate Factor Range Introduced



New Service Letter, Breaking-In: Unchanged



Familiarisation of the ACC factor


Henrik Rolsted

Senior Research Engineer

LEO / Engineering MAN Diesel & Turbo

S60M7

0

50

100

150

200

250

300

350

400

0,10 0,15 0,20 0,25 0,30 0,35 0,40

Iro

n c

on

ten

t in

dra

in o

il (

pp

m)

Feed-rate factor (g/kWh) x S% (3.64)

8S60 ME-C7

Cyl 1

Cyl 2

Cyl 3

Cyl 4

Cyl 5

Cyl 6

Cyl 7

Cyl 8

Average

Poly. (Cyl 4)

Poly. (Cyl 5)

HFO 3.64 % S LOAD 50% MCR


Quicker Familiarisation of the ACC factor


Henrik Rolsted

Senior Research Engineer

LEO / Engineering MAN Diesel & Turbo

S60M7

0

5

10

15

20

25

30

35

40

45

0,10 0,15 0,20 0,25 0,30 0,35 0,40

BN

in

dra

in o

il (

mg

KO

H/g

)

Feed-rate factor (g/kWh) x S% (3.64)

8S60 ME-C7

Cyl 1

Cyl 2

Cyl 3

Cyl 4

Cyl 5

Cyl 6

Cyl 7

Cyl 8

Average

Poly. (Cyl 2)

Poly. (Cyl 5)


Quicker familiarisation of the ACC factor

HFO 3.64 % S

LOAD 50% MCR



New Cylinder Lubrication Update, New Service Letter


First Commercial 6S80ME-C9-EGR

In Service

MAN B&W Service Experience 2013

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