MAN B&W 7.09
Page 4 of 7
MAN Diesel
MAN B&W ME-GI TII engines 198 86 39-0.2
Inert gas system
The inert gas system is required for purging of all
fuel gas piping associated with the ME-GI instal-
lation. See the diagram of gas supply auxiliary
systems Fig 7.09.01.
The inert gas for purging of the Fuel Gas Supply
(FGS) system can either be supplied from a com-
mon inert gas system, or a separate stand alone
system. This will depend on the individual instal-
lation.
A sufficient quantity of inert gas must be available
on board before beginning to operate the engine
on fuel gas.
General data for the inert gas system
Medium: .............................................................. N
2
Purging pressure: ...................................... 7 - 9 bar
Control of the inert gas system
The inert gas system is to be equipped with the
interface signals described in Fig. 16.02.03 ‘GI
Extension Interface to External Systems’, with
reference to the signals going to and from ‘Inert
Gas System’. When operating in ‘remote’ mode,
the inert gas system is controlled by the GI control
system.
Inert gas pipe connections
Please refer to Section 7.00 for estimating pipe di-
mensions based on engine power. The actual pipe
dimensions must also be verified with Yard.
Safety requirements
For marine applications, the inert gas system is to
be delivered with a Class approved product cer-
tificate.
Purging volume and storage capacity
The purging storage volume (or capacity) should
also be designed for a number of consecutive
starts on fuel gas. Our guideline is to design the
system for 6 consecutive fuel gas starts.
In order to calculate the purging volume, the total
volume of piping being purged must be calculat-
ed. The purging sequences are described in Table
7.09.03 with reference to Fig. 7.09.04.
Calculating the purging volume
The purge sequence is performed a maximum of
5 times, dependent on measurement by the HC
sensors in the return pipe. Furthermore, the sys-
tem must be purged before start in fuel gas mode.
Consequently a guideline for calculating the inert
gas storage volume is:
Purging volume = 6 × 5 × 2 × (V
sect 1
+ V
sect 2
)
the numbers meaning:
• 6 consecutive fuel gas starts
• 5 runs of purge sequence maximum
• 2 purges before start in fuel gas mode.
To Next Page
Loading...
Need help?
General
