Man B&W S80ME-C7 User Manual

MAN B&W 2.04
Page 2 of 
MAN Diesel
MAN B&W ME/ME-C/ME-GI engines
198 38 97-3.6
Engine shaft power, % of A
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
7
5
4
1 2
6
7
8
4
1
2
6
5
O
A=M
3
9
Engine speed, % of A
60
65
70
75
80
85 90 95 100 105 110
A 00% reference point
M Specied MCR
O Matching point
Fig. 2.04.02: Standard engine load diagram
Regarding ‘i’ in the power function P = c x n
i
, see page 2.0
178 05 427.3
Engine Load Diagram
Denitions
The engine’s load diagram denes the power and
speed limits for continuous as well as overload
operation of an installed engine having a specied
MCR point M that conrms the ship’s specication.
Point A is a 00% speed and power reference
point of the load diagram, and is dened as the
point on the propeller curve (line ),  the layout
curve of the engine  through the matching point
O, having the specied MCR power. Normally,
point M is equal to point A, but in special cases,
for example if a shaft generator is installed, point
M may be placed to the right of point A on line 7.
However, MAN Diesel may always consider point
A as the engine’s MCR for shop test.
In most cases, the points M and A are identical.
The service points of the installed engine incorpo-
rate the engine power required for ship propulsion
and shaft generator, if installed.
Operating curves and limits for continuous
operation
The continuous service range is limited by four
lines:
4, 5, 7 and 3 (9), see Fig. 2.04.02. The propeller
curves, line , 2 and 6 in the load diagram are also
described below.
Line 1:
Propeller curve through specied MCR (M), en-
gine layout curve (i = 3).
Line 2:
Propeller curve, fouled hull and heavy weather
– heavy running (i = 3).
Line 3 and line 9:
Line 3 represents the maximum acceptable speed
for continuous operation, i.e. 05% of A.
During trial conditions the maximum speed may
be extended to 07% of A, see line 9.
The above limits may in general be extended to
05% and during trial conditions to 07% of the
nominal L

speed of the engine, provided the tor-
sional vibration conditions permit.
The overspeed setpoint is 09% of the speed
in A, however, it may be moved to 09% of the
nominal speed in L

, provided that torsional vibra-
tion conditions permit.
Running at low load above 00% of the nominal L

speed of the engine is, however, to be avoided for
extended periods. Only plants with controllable
pitch propellers can reach this light running area.
Line 4:
Represents the limit at which an ample air supply
is available for combustion and imposes a limita-
tion on the maximum combination of torque and
speed (i = 2).
Line 5:
Represents the maximum mean effective pressure
level (mep), which can be accepted for continuous
operation (i = ).

Man B&W S80ME-C7 Specifications

General

Brand	Man
Model	B&W S80ME-C7
Category	Engine
Language	English