Marine Installation Manual
2021-08
4-96
4 Ancillary Systems
4.10 Engine room ventilation
X72DF
Arrangement 2 — Direct engine ventilation system
Layout
In this arrangement, the ventilation outlets are coupled with the turbocharger in
-
lets. As the turbochargers directly receive all the outside ambient air drawn via
the ventilation system, there is little chance for the temperature to increase. As a
result, this arrangement delivers cooler air to the engine than in ‘Arrangement 1’,
reducing the engine’s brake specific fuel consumption.
Figure 4
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53 Ventilation system arrangement 2 — Direct engine ventilation system
The outside ambient air is drawn through the ventilation system by the turbo
-
chargers, and therefore there is no need for ventilation fans in this arrangement.
However, it is still essential that the ventilation inlet is protected, typically with
a weather hood and louvres. A separate filter unit, if required, can also be fitted
here, within the inlet housing.
Requirements
The engine room ventilation system is provided with separate ventilation fans
and ducting. It should be appropriately sized to provide comfortable working
conditions in the engine room, supply the necessary combustion air for auxiliary
generator(s) and the boiler, and to prevent heat-sensitive apparatus from over
-
heating.
As the main engine combustion air is no longer provided for by the engine room
ventilation system, the energy demand of the ventilation fans is reduced com
-
pared to ‘Arrangement 1’.
SM-0512
Main
engine
Auxiliary
generator
Ventilation outlets
directly coupled to
Turbocharger inlet
Ventilation inlet
Weather hood, louvres etc.
Ventilation system
