Special Running Conditions - Man B&W S50MC-C8-TII Project Manual

MAN B&W
Example 2: Special running conditions.
Engine coupled to a fixed pitch propeller (FPP) and without a shaft generator
Layout diagram
Power, % of L
Power, % of L
1
1
100%
100%
7
7
5
5
4
4
1 2 6
1 2 6
L
L
3
3
L
L
4
4
Engine speed, % of L
Engine speed, % of L
M Specified MCR of engine
S Continuous service rating of engine
O Optimising point of engine
A Reference point of load diagram
MP Specified MCR for propulsion
SP Continuous service rating of propulsion
In this example, the optimising point O has been selected
more to the left than in Example 1, providing an extra en-
gine margin for heavy running operation in heavy weather
conditions. In principle, the light running margin has been
increased for this case.
Fig. 2.04.05: Special running conditions. Engine coupled to a fixed pitch propeller (FPP) and without a shaft generator
MAN B&W MC/MC-C-TII engines
L
L
1
1
A=O
A=O
7
7
M=MP
M=MP
S=SP
S=SP
L
2 6
1 L
1 2 6
2
2
Propulsion and engine
Propulsion and engine
service curve for fouled
service curve for fouled
hull and heavy weather
hull and heavy weather
100%
100%
1
1
Load diagram
Power, % of L
Power, % of L
1
1
100%
100%
L
L
3
3
L
L
4
4
Point A of the load diagram is found:
Line 1 Propeller curve through optimising point (O)
placed to the left of line 2
Line 7 Constant power line through specified MCR (M)
Point A Intersection between line 1 and 7
MAN Diesel
3.3%A 5%A
3.3%A 5%A
A=O
A=O
7
7
5
5
M
M
S
S
4 1 2 6
2
4 1 6
3
3
Propulsion and engine
Propulsion and engine
service curve for fouled
service curve for fouled
hull and heavy weather
hull and heavy weather
Engine speed, % of L
Engine speed, % of L
1
1
2.04
Page 7 of 10
L
L
1
1
5%L
5%L
1
1
L
L
2
2
3
3
100%
100%
178 39 23-1.1
198 69 94-7.1