Straight run residues show CCAI values in the 770 to 840 range and have very good ignition quality. Cracked
residues delivered as bunkers may range from 840 to - in exceptional cases - above 900. Most bunkers remain
in the max. 850 to 870 range at the moment. CCAI value cannot always be considered as an accurate tool to
determine the ignition properties of the fuel, especially concerning fuels originating from modern and more
complex refinery process.
3)
The max. sulphur content must be defined in accordance with relevant statutory limitations.
4)
Sodium contributes to hot corrosion on the exhaust valves when combined with high sulphur and vanadium
contents. Sodium also strongly contributes to fouling of the exhaust gas turbine blading at high loads. The ag-
gressiveness of the fuel depends on its proportions of sodium and vanadium and also on the total amount of
ash. Hot corrosion and deposit formation are, however, also influenced by other ash constituents. It is therefore
difficult to set strict limits based only on the sodium and vanadium content of the fuel. Also a fuel with lower
sodium and vanadium contents than specified above, can cause hot corrosion on engine components.
5)
The implementation date for compliance with the limit shall be 1 July 2012. Until that, the specified value is
given for guidance.
6)
It shall be ensured that the pour point is suitable for the equipment on board, especially if the ship operates in
cold climates.
7)
The fuel shall be free from used lubricating oil (ULO). A fuel shall be considered to contain ULO when either one
of the following conditions is met:
•
Calcium > 30 mg/kg and zinc > 15 mg/kg
•
Calcium > 30 mg/kg and phosphorus > 15 mg/kg
8)
6.1.3 Liquid bio fuels
The engine can be operated on liquid bio fuels according to the specifications in tables "
" or "
6.5 Biodiesel specification based on EN 14214:2003 standard
". Liquid bio fuels
have typically lower heating value than fossil fuels, the capacity of the fuel injection system must be checked
for each installation.
If a liquid bio fuel is to be used as pilot fuel, only pilot fuel according to table "
" is allowed.
Table "
Straight liquid bio fuel specification
" is valid for straight liquid bio fuels, like palm oil, coconut oil,
copra oil, rape seed oil, jathropha oil etc. but is not valid for other bio fuel qualities like animal fats.
Renewable biodiesel can be mixed with fossil distillate fuel. Fossil fuel being used as a blending component
has to fulfill the requirement described earlier in this chapter.
Table 6.4 Straight liquid bio fuel specification
Test method ref.
Limit
Unit
Property
ISO 3104
100
cSt
Viscosity at 40°C, max.
1)
2.0
cSt
Viscosity, before injection pumps, min.
24
cSt
Viscosity, before injection pumps, max.
ISO 3675 or 12185
991
kg/m³
Density at 15°C, max.
FIA test
Ignition properties
2)
ISO 8574
0.05
% mass
Sulphur, max.
ISO 10307-1
0.05
% mass
Total sediment existent, max.
ISO 3733
0.20
% volume
Water before engine, max.
ISO 10370
0.50
% mass
Micro carbon residue, max.
ISO 6245 / LP1001
0.05
% mass
Ash, max.
ISO 10478
100
mg/kg
Phosphorus, max.
ISO 10478
15
mg/kg
Silicon, max.
ISO 10478
30
mg/kg
Alkali content (Na+K), max.
ISO 2719
60
°C
Flash point (PMCC), min.
ISO 3015
3)
°C
Cloud point, max.
IP 309
3)
°C
Cold filter plugging point, max.
ASTM D130
1b
Rating
Copper strip corrosion (3h at 50°C), max.
Product Guide Wärtsilä 34DF - 3/2012
39
Product Guide
6. Fuel System
