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MAN B&W 9.02
MAN B&W Alpha Cylinder Lubrication System
The MAN B&W Alpha cylinder lubrication system,
see Figs. 9.02.02a and 9.02.02b, <strong>is</strong> designed to
supply cylinder oil intermittently, e.g. every four
engine revolutions with electronically controlled
timing and dosage at a defined position.
The cylinder lubricating oil <strong>is</strong> pumped from the
cylinder oil storage tank to the service tank, the
size of which depends on the owner’s and the
yard’s requirements, � it <strong>is</strong> normally dimensioned
for minimum two days’ cylinder lubricating oil
consumption.
Cylinder lubricating oil <strong>is</strong> fed to the Alpha cylinder
lubrication system by gravity from the service
tank.
The storage tank and the service tank may alternatively
be one and the same tank.
The oil fed to the injectors <strong>is</strong> pressur<strong>is</strong>ed by
means of the Alpha Lubricator which <strong>is</strong> placed
on the HCU and equipped with small multi�p<strong>is</strong>ton
pumps.
The oil pipes fitted on the engine <strong>is</strong> shown in Fig.
9.02.04.
The whole system <strong>is</strong> controlled by the Cylinder
Control Unit (CCU) which controls the injection
frequency on the bas<strong>is</strong> of the engine�speed signal
given by the tacho signal and the fuel index.
Prior to start-up, the cylinders can be pre�lubricated
and, during the running�in period, the operator
can choose to increase the lubricating oil feed
rate to a max. setting of 200%.
The MAN B&W Alpha Cylinder Lubricator <strong>is</strong> preferably
to be controlled in accordance with the Alpha
ACC (Adaptive Cylinder oil Control) feed rate
system.
The yard supply should be according to the items
shown in Fig. 9.02.02a within the broken line. With
regard to the filter and the small box, plese see
Fig. 9.02.05.
Alpha Adaptive Cylinder oil
Control (Alpha ACC)
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It <strong>is</strong> a well�known fact that the actual need for
cylinder oil quantity varies with the operational
conditions such as load and fuel oil quality. Consequently,
in order to perform the optimal lubrication
– cost�effectively as well as technically – the
cylinder lubricating oil dosage should follow such
operational variations accordingly.
The Alpha lubricating system offers the possibility
of saving a considerable amount of cylinder lubricating
oil per year and, at the same time, to obtain
a safer and more predictable cylinder condition.
Working Principle
The basic feed rate control should be adjusted in
relation to the actual fuel quality and amount being
burnt at any given time. The sulphur percentage
<strong>is</strong> a good indicator in relation to wear, and an
oil dosage proportional to the sulphur level will
give the best overall cylinder condition.
The following two criteria determine the control:
• The cylinder oil dosage shall be proportional to
the sulphur percentage in the fuel
• The cylinder oil dosage shall be proportional to
the engine load (i.e. the amount of fuel entering
the cylinders).
The implementation of the above two criteria will
lead to an optimal cylinder oil dosage, proportional
to the amount of sulphur entering the cylinders.
Safe and very lubricating�economical control after
running-in <strong>is</strong> obtained with a basic setting according
to the formula:
Basic lubricating oil setting = 0.26 g/kWh x S%
with a minimum setting of 0.60 g/kWh, i.e. the
setting should be kept constant from about 2.3%
sulphur and downwards.
MAN B&W ME/ME�C/ME-B/ME�GI engines 198 38 89�0.7
MAN Diesel