d)
The water content
of heavy fuel oils varies widely. Water may come
from several different sources, it can either be fresh or salt. It can
also originate from e.g. condensation in the installation’s bunker
tanks.
·
If the water is sweet and very well emulsified in the fuel, the
effective energy content of the fuel decreases with increasing
water content, leading to an increase in fuel consumption.
·
If the fuel is contaminated with sea water, the chlorine in the
salt will cause corrosion of the fuel handling system, including
the injection equipment. The effects of sodium, that also origi-
nates from salt, are described more in detail below.
To avoid difficulties in the engine fuel injection system the water
content must be reduced to a max. of 0.3 % prior to the engine.
e)
The sulphur
in the fuel may cause cold corrosion and corrosive
wear, especially at low loads. Sulphur also contributes to deposit
formation in the exhaust system, normally together with vanadium
and/or sodium in the form of sulphates. The deposits can also cause
high temperature corrosion, as described below.
f)
A high ash content
may be detrimental in several ways. Different
ash components can cause different problems:
·
Aluminium and silicon
oxides originate from the refining proc-
ess, and can cause severe abrasive wear mainly of the injec-
tion pumps and nozzles, but also of cylinder liners and piston
rings. An efficient fuel separation is a must for minimising wear.
·
Oxides of
vanadium and sodium
, mainly sodium vanadyl
vanadates, are formed during the combustion, and mix or
react with oxides and vanadates of other ash components,
e.g. nickel, calcium, silicon and sulphur. The sticking tempera-
ture of the mixture may be such, that a deposit is formed on a
valve, in the exhaust gas system, or in the turbo-charger. This
deposit is highly corrosive in the molten state, destroying the
protective oxide layer on e.g. an exhaust valve, and leading
to hot corrosion and a burned valve. Deposits and hot corro-
sion in the turbocharger, especially on the nozzle ring and
turbine blades will cause a decreased turbocharger effi-
ciency. The gas exchange will be disturbed, less air flows
through the engine, and thus the thermal load on the engine
increases. The deposit formation increases at increased tem-
peratures and engine outputs.
To avoid the above mentioned problems when running on high ash
fuels, it is important to:
·
Have an efficient fuel separation.
·
Clean the turbocharger regularly with water, see section 15.3.
·
Have a strict quality control of the bunkered fuel, i.e. to see
that the amounts of ash and dangerous ash constituents stay
low.
·
Maintain clean air filters and charge air coolers by regular
cleaning based on pressure drop monitoring.
200549-01
Fuel, Lubricating Oil, Cooling Water
W20/W32/W46, W46F, 32, 32LN
02 - 9
Summary of Contents for PAAE051728
Page 4: ......
Page 18: ...Appendix B Welding Precautions 200640 00 6...
Page 26: ...01 Main Data Operating Data and General Design 32 200634 01 01 8 W RTSIL 32...
Page 60: ...Appendix A Environmental Hazards 200507 02A 10...
Page 68: ...Page 7 7 Document No 4V92A0645 Rev j...
Page 84: ...03 Start Stop and Operation 32 200402 04 03 12 W RTSIL 32...
Page 98: ...04 Maintenance Schedule 32 200623 01 04 14 W RTSIL 32...
Page 154: ...07 Tightening Torques and Use of Hydraulic Tools 32 200643 01 07 30 W RTSIL 32...
Page 162: ...08 Operating Troubles Emergency Operation 32 200402 01 08 8 W RTSIL 32...
Page 164: ...Specific Installation Data 2005 01 09 2...
Page 178: ...10 Engine Block with Bearings Oil Sump and Cylinder Liner 32 200150 10 14 W RTSIL 32 34SG...
Page 216: ...Appendix A Testing of cylinder tightness 32 200142 A 4 W rtsil 20 32 34...
Page 226: ...13 Camshaft Driving Gear 32 200546 02 13 10 W RTSIL 32...
Page 254: ...15 Turbocharging and Air Cooling 32 200549 10 15 20 W RTSIL 32...
Page 274: ...16 Injection System 32 200627 01 16 20 W RTSIL 32...
Page 280: ...Fuel System 32 200508 07 17 6 W RTSIL 32...
Page 314: ...19 Cooling Water System 32 200050 19 14 W RTSIL 32...
Page 394: ...23 Instrumentation and Automation 32 200115 II 23 60 W RTSIL 32...
