MAN B&W S65ME-C8.2-GI-TII, Project Manual

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MAN B&W 1.06
Page 4 of 7
MAN Diesel 198 89 14-5.2 MAN B&W 90-50ME-C8-GI TII .2 and higher
Scavenge Air Cooler
For each turbocharger is fitted a scavenge air
cooler of the monoblock type designed for sea-
water cooling, alternatively, a central cooling sys-
tem with freshwater can be chosen. The working
pressure is up to 4.5 bar.
The scavenge air cooler is so designed that the
difference between the scavenge air temperature
and the water inlet temperature at specified MCR
can be kept at about 12 °C.
Auxiliary Blower
The engine is provided with electricallydriven
scavenge air blowers integrated in the scavenge
air cooler. The suction side of the blowers is con-
nected to the scavenge air space after the air
cooler.
Between the air cooler and the scavenge air re-
ceiver, nonreturn valves are fitted which auto-
matically close when the auxiliary blowers supply
the air.
The auxiliary blowers will start operating con-
secutively before the engine is started in order to
ensure sufficient scavenge air pressure to obtain a
safe start.
Further information is given in Chapter 14.
Exhaust Gas System
From the exhaust valves, exhaust gas is led to
the exhaust gas receiver where the fluctuating
pressure from the individual cylinders is equal-
ised, and the total volume of gas is led to the
turbocharger(s). After the turbocharger(s), the gas
is led to the external exhaust pipe system.
Compensators are fitted between the exhaust
valves and the receiver, and between the receiver
and the turbocharger(s).
The exhaust gas receiver and exhaust pipes are
provided with insulation, covered by galvanised
steel plating.
A protective grating is installed between the ex-
haust gas receiver and the turbocharger.
Exhaust Turbocharger
The engines can be fitted with either MAN, ABB or
MHI turbochargers. As an option, MAN TCA tur-
bochargers can be delivered with variable nozzle
technology that reduces the fuel consumption at
part load by controlling the scavenge air pressure.
The turbocharger selection is described in Chap-
ter 3, and the exhaust gas system in Chapter 15.
Reversing
Reversing of the engine is performed electronical-
ly and controlled by the Engine Control System,
by changing the timing of the fuel injection, the
exhaust valve activation and the starting valves.
The Hydraulic Power Supply
The Hydraulic Power Supply (HPS) filters and
pressurises the lube oil for use in the hydraulic
system. The HPS consists of either mechanically
driven (by the engine) main pumps with electrically
driven start-up pumps or electrically driven com-
bined main and start-up pumps. The hydraulic
pressure varies up to max 300 bar.
The mechanically driven HPS is engine driven and
mounted aft for engines with chain drive aft (8 cyl-
inders or less), and at the middle for engines with
chain drive located in the middle (9 cylinders or
more). An electrically driven HPS is usually mount-
ed aft on the engine.
A combined HPS, mechanically driven with elec-
trically driven start-up/back-up pumps with back-
up capacity, is available as an option for engines
type 90-60 while basic execution for type 50.