Specific Fuel Oil Consumption, Me Versus Mc Engines - Man B&W S50ME-B9.3-TII Project Manual

MAN B&W

Specific Fuel Oil Consumption, ME versus MC engines

As previously mentioned the main feature of the
ME/ME-C engine is that the fuel injection and the
exhaust valve timing are optimised automatically
over the entire power range, and with a minimum
speed down to around 15-20% of the L
but around 20-25% for MC/MC-C.
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/
ME-C engine is at 70% of M, whereas it is at 80%
of M for the MC/MC-C/ME-B engine.
Fig. 2.06.01: Example of part load SFOC curves for ME and MC with fixed pitch propeller
MAN B&W 70-26 MC/MC-C/ME/ME-C engines
speed,
1
∆ SFOC
g/kWh ±5%
MC
ME
30 35 40 45 50
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 & Turbo.
The calculation of the expected specific fuel oil
consumption (SFOC) valid for standard high load
optimised engines can be carried out by means of
the following figures for fixed pitch propeller and
for controllable pitch propeller, constant speed.
Throughout the whole load area the SFOC of the
engine depends on where the specified MCR
point (M) is chosen.
55 60 65 70 75 80
Engine power, % of specified MCR point M
MAN Diesel
85 90 95 100 105
2.06
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