Examples Of The Use Of The Load Diagram - Man B&W S80ME-C7 Project Manual

MAN B&W
Line : Propeller curve through matching point (O)  layout
curve for engine
Line 2: Heavy propeller curve
 fouled hull and heavy seas
Line 3: Speed limit
Line 3': Extended speed limit, provided torsional vibration
conditions permit
Line 4: Torque/speed limit
Line 5: Mean effective pressure limit
Line 6: Increased light running propeller curve
 clean hull and calm weather
 layout curve for propeller
Line 7: Power limit for continuous running
Fig. 2.04.03: Extended load diagram for speed derated
engine with increased light running
MAN B&W ME/ME-C/ME-GI engines

Examples of the use of the Load Diagram

In the following are some examples illustrating the
flexibility of the layout and load diagrams and the
significant influence of the choice of the matching
point O.
•
Example  shows how to place the load diagram
for an engine without shaft generator coupled to
a fixed pitch propeller.
•
Example 2 are diagrams for the same configura-
tion, but choosing a matching point on the left
of the heavy running propeller curve (2) provid-
ing an extra engine margin for heavy running
similar to the case in Fig. 2.04.03.
•
Example 3 shows the same layout for an engine
with fixed pitch propeller (example ), but with a
shaft generator.
•
Example 4 is a special case of example 3, where
the specified MCR is placed near the top of the
layout diagram.
In this case the shaft generator is cut off,
and the GenSets used when the engine runs
at specified MCR. This makes it possible to
178 52 256.0
choose a smaller engine with a lower power out-
put.
•
Example 5 shows diagrams for an engine
coupled to a controllable pitch propeller, with or
without a shaft generator.
•
Example 6 shows where to place the matching
point for an engine coupled to a controllable
pitch propeller.
For a specific project, the layout diagram for actu-
al project shown later in this chapter may be used
for construction of the actual load diagram.
MAN Diesel
2.04
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