Specific Fuel Oil Consumption, Me Versus Mc Engines - Man B&W S80ME-C7 Project Manual

MAN B&W

Specific Fuel Oil Consumption, ME versus MC engines

As previously mentioned the main feature of the
ME engine is that the fuel injection and the ex-
haust valve timing are optimised automatically
over the entire power range, and with a minimum
speed down to around 5% of the L
Comparing the specific fuel oil comsumption
(SFOC) of the ME and the MC engines, it can be
seen from the figure below that the great advan-
tage of the ME engine is a lower SFOC at part
loads.
It is also noted that the lowest SFOC for the ME
engine is at 70% of O, whereas it was at 80% of O
for the MC engine.
SFOC
g/kWh
+3
+2
+1
0
-1
-2
-3
-4
-5
Fig. 2.06.01: Example of part load SFOC curves for ME and MC with fixed pitch propeller
MAN B&W ME/ME-C/ME-GI
speed.

MC
ME
70%
50% 60%
Engine power, % of matching point O
For the ME engine only the turbocharger matching
and the compression ratio (shims under the piston
rod) remain as variables to be determined by the
engine maker / MAN Diesel.
The calculation of the expected specific fuel oil
consumption (SFOC) can be carried out by means
of the following figures for fixed pitch propel-
ler and for controllable pitch propeller, constant
speed. Throughout the whole load area the SFOC
of the engine depends on where the matching
point (O) is chosen.
80% 90%
MAN Diesel
100% 110%
2.06
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