Lubricating oil Supply System
Two independent lubricating oil systems:
✔ The main lubricating oil system maintains the
oil pressure in the system and supplies it from the main engine crankcase to
the crankshaft, connecting rods and crosshead engine. This LO also lubricates
turbocharger, camshaft, chain drive and thrust bearings, and cools the pistons.
✔ Cylinder oil system, to lubricate the cylinder
bushes and piston rings supplies oil from ME CO Service Tank. This is a
"one-off" total complete system in which all the oil fed to the
engine is lost and not returned to the system.
Lubricating oil system of The Main Engine
Lubricating oil system of The Main Engine
The ME lubricating oil system consist of:
1.
ME CO Transfer Pump;
2.
ME CO Unit;
3.
ME LO Auto Filter 250m3/h, performance, trapping
particles up to 50μm in size;
4.
ME LO Bypass Filter.
250m3/h, performance, trapping particles up to 50μm in size;
5.
ME LO Cooler;
6.
Two of ME LO Pump.
Centrifugal - vertical, submersible type.
Two vertical, submersible,
centrifugal pumps are at the rear of the main engine, at floor level of ME LO
in the crankcase tank. These pumps can replace each other in standby mode. They
supply circulating oil to the main connecting rod, cross bearings and other
internal gears such as chain drives and thrust bearings.
The oil to crosshead supplied by telescopic
tubes and used to lubricate the crosshead bearing and its guide slides. Further
through the crankcase holes, oil is supplied to the crankcase bearings. From
the bearings, the oil drains into the lower crankcase, from where it passes
through the mesh strainers to the double bottom ME LO crankcase tank.
The supply of oil for cooling the piston to
the cooling cavities of the piston bottom takes place in the opening of the
piston rod in the central tube. After cooling the piston, the grease flows down
the outer surface of the supply pipe in the piston rod back to the crosshead
and continues to drain down to the lower crankcase. Each individual piston
cooling line has flow sensors that trigger an alarm when the oil flow is lost.
The oil temperature is also monitored.
NOTE: Once
the pumps are set AUTO CHANGE mode, the stand-by (non-running) pump starts
automatically when the pump is running or if the lubrication system pressure
becomes too low. However, if the service pump is stopped from any of its
control panels (even accidentally), the on-call pump will not start because the
control system will recognize the shutdown signal as a function of the operator
command rather than a lubrication system failure.
Lubricating oil for camshaft bearings, for
its cam boxes and valve lifters, a separate line is supplied for the
lubrication of the fuel pump and the actuators of the exhaust valves. Branching
from the main oil supply flow from the automatic or bypass filter. The grease
then drains from the distribution boxes into the ME LO crankcase tank.
The main circulating oil pumps supply the
oil through a plate cooler which is cooled by a low temperature central cooling
system. The oil temperature is controlled by a thermostatic modulating
three-way valve, which directs the amount of oil through the cooler to maintain
the set circulating oil temperature. The oil from the cooler passes through an
automatic, backwash filter unit before entering the main engine.
The automatic filter is regularly flushed
with a return flow of oil. In this way, solid particles trapped on the filter
surface are not allowed to adhere. This cleans the entire surface area of the
filter every few minutes, ensuring a long service life of the reinforced filter
elements. The automatic filter alarm is activated if the pressure difference
between the incoming and outgoing oil reaches 0,09 MPa.
The automatic filter bypass filter is
intended for use when the automatic backwash filter is disconnected for
maintenance.