•
Danger area
The danger limit for piston underside residual BN is lower than BN 10. In this area it is
possible that excessive corrosion can occur. Thus the piston rings and cylinder liners can
become quickly worn. Also scuffing can occur. Piston rings can quickly become defective.
The danger limit for iron (Fe) content in the drain oil is more than 500 mg/kg.
Do not operate the engine in these danger areas.
12.4.2.6
Optimization of the feed rate
After you have done the interpretation of the oil analysis, you can do an optimization of the feed
rate as follows:
1
If the analysis shows operation in the safe area, do one of the two instructions:
a
Continue the operation with the set feed rate.
b
Decrease the feed rate in small steps, eg in steps of 0.05 g/kWh.
2
If the analysis shows operation in one of the alert areas, do one of the two instructions:
a
Increase or decrease the feed rate to get the operation in the safe area. If necessary,
change the BN of the cylinder oil.
b
Keep the feed rate and do regular checks of the piston ring and the cylinder liner
conditions through scavenge port inspections.
3
If the analysis shows operation in the danger area, do as quickly as possible as follows:
a
Increase or decrease the feed rate or change the BN of the cylinder oil to get the
operation in the safe area.
NOTE:
WinGD has made a tool (piston underside drain oil analysis) for easier interpretation of
the oil analysis. If necessary, the tool gives you recommendations and procedures to
make the cylinder oil system better. Only use the tool, if you use a cylinder oil with BN 40
or higher.
If you want to use the tool, speak to or send a message to WinGD.
WinGD recommends to collect the data from the oil analyses. When you later use a fuel with the
same sulphur content (±0.125% m/m) and a cylinder oil with the same BN, you can set the feed
rate related to the collected data with the same conditions. You also can use these data to get
continuously better performance of the cylinder oil.
12.4.3
Effective feed rate
The cylinder lubricating feed rate that is set in the engine control system is the specific feed rate
at 100% CMCR. At part load operation, a correction factor is applied in order to make sure a
sufficient quantity of cylinder oil. Thus the effective feed rate at part load is higher than the set feed
rate.
X52
AA00-0000-00AAA-030G-A
Operation Manual
Cylinder oils
Winterthur Gas & Diesel Ltd.
- 459 -
Issue 002 2018-11
