MAN B&W S65ME-C8.2-GI-TII, Project Manual

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MAN B&W 1.00
Page 2 of 2
MAN Diesel MAN B&W ME-GI engines 198 91 51-6.1
• Control and safety system, comprising
a hydrocarbon analyser for checking the
hydrocarbon content of the air in the double-
wall gas pipes.
Engine operating modes
One main advantage of the ME-GI engine is its
fuel flexibility. The control concept comprises
three different fuel modes, see Fig. 1.00.02:
• gas operation with minimum pilot oil amount
• specified dual fuel operation (SDF) with injection
of a fixed gas amount
• fuel-oil-only mode.
Gas operation mode is used for gas operation.
It can only be started manually by an operator on
the Main Operating Panel (MOP) in the control
room. The minimum preset amount of pilot fuel oil
is as little as 3% at SMCR.
Specified dual fuel operation (SDF) mode gives
the operator full fuel flexibility and the option to
inject a fixed amount of gas fuel. The ME control
system adds fuel oil until the required engine load
is reached.
Fuel-oil-only mode is known from the ME engine.
Operating the engine in this mode can only be
done on fuel oil. In this mode, the engine is con-
sidered ‘gas safe’. If a failure in the gas system
occurs, it results in a gas shutdown and a return
to the fuel-oil only mode.
Safety
The ME-GI control and safety system is designed
to fail to safe condition. All failures detected dur-
ing gas fuel running result in a gas fuel stop and
a change-over to fuel oil operation. This condition
applies also to failures of the control system itself.
Following the change-over, the high-pressure gas
pipes and the complete gas supply system are
blown-out and freed from gas by purging.
The change-over to fuel oil mode is always done
without any power loss of the engine.
Fuel gas supply systems
Different applications call for different gas supply
systems, and operators and shipowners demand
alternative solutions.
Therefore, MAN Diesel & Turbo aims to have a
number of different gas supply systems prepared,
tested and available. Examples of fuel gas supply
systems are presented in Section 7.08.
Fig. 1.00.02: Fuel type modes for the ME-GI engines for
LNG carriers
0 10 20 30 40 50
Engine load (%SMCR)
% Fuel
% Fuel
60 70 80 90 100
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
0 10 20 30 40 50
Engine load (%SMCR)
60 70 80 90 100
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Gas operation mode
Specified dual fuel operation mode
% Total
% Pilot
% Total
% Pilot
178 65 963.1