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

Page: 15 / 395

MAN B&W 1.01
Page 1 of 2
MAN Diesel 198 85 37-1.4 MAN B&W 98ME/ME-C7-TII .1,
95-40ME-C/-GI-TII .5/.4/.2 engines
The ever valid requirement of ship operators is
to obtain the lowest total operational costs, and
especially the lowest possible specific fuel oil
consumption at any load, and under the prevailing
operating conditions.
However, lowspeed twostroke main engines
of the MC-C type, with a chain driven camshaft,
have limited flexibility with regard to fuel injection
and exhaust valve activation, which are the two
most important factors in adjusting the engine to
match the prevailing operating conditions.
A system with electronically controlled hydraulic
activation provides the required flexibility, and
such systems form the core of the ME Engine
Control System, described later in detail in Chap-
ter 16.
Concept of the ME engine
The ME engine concept consists of a hydraulic-
mechanical system for activation of the fuel injec-
tion and the exhaust valves. The actuators are
electronically controlled by a number of control
units forming the complete Engine Control Sys-
tem.
MAN Diesel & Turbo has specifically developed
both the hardware and the software inhouse, in
order to obtain an integrated solution for the En-
gine Control System.
The fuel pressure booster consists of a simple
plunger powered by a hydraulic piston activated
by oil pressure. The oil pressure is controlled by
an electronically controlled proportional valve.
The exhaust valve is opened hydraulically by
means of a twostage exhaust valve actuator
activated by the control oil from an electronically
controlled proportional valve. The exhaust valves
are closed by the ‘air spring’.
In the hydraulic system, the normal lube oil is used
as the medium. It is filtered and pressurised by a
Hydraulic Power Supply unit mounted on the en-
gine or placed in the engine room.
The starting valves are opened pneumatically by
electronically controlled ‘On/Off’ valves, which
make it possible to dispense with the mechani-
cally activated starting air distributor.
By electronic control of the above valves accord-
ing to the measured instantaneous crankshaft po-
sition, the Engine Control System fully controls the
combustion process.
System flexibility is obtained by means of different
‘Engine running modes’, which are selected either
automatically, depending on the operating condi-
tions, or manually by the operator to meet specific
goals. The basic running mode is ‘Fuel economy
mode’ to comply with IMO NO
x
emission limita-
tion.
Engine design and IMO regulation compliance
The ME-C engine is the shorter, more compact
version of the ME engine. It is well suited wherever
a small engine room is requested, for instance in
container vessels.
For MAN B&W ME/ME-C-TII designated engines,
the design and performance parameters comply
with the International Maritime Organisation (IMO)
Tier II emission regulations.
For engines built to comply with IMO Tier I emis-
sion regulations, please refer to the Marine Engine
IMO Tier I Project Guide.
The Fuel Optimised ME Tier II Engine