External Cooling Water System - Wartsila ?31DF Series Product Manual

9. Cooling Water System
9.2

External cooling water system

It is recommended to divide the engines into several circuits in multi-engine installations. One
reason is of course redundancy, but it is also easier to tune the individual flows in a smaller
system. Malfunction due to entrained gases, or loss of cooling water in case of large leaks
can also be limited. In some installations it can be desirable to separate the HT circuit from
the LT circuit with a heat exchanger.
The external system shall be designed so that flows, pressures and temperatures are close
to the nominal values in Technical data and the cooling water is properly de-aerated.
Pipes with galvanized inner surfaces are not allowed in the fresh water cooling system. Some
cooling water additives react with zinc, forming harmful sludge. Zinc also becomes nobler
than iron at elevated temperatures, which causes severe corrosion of engine components.
Fig 9-1
System components:
4E03
4E05
4E08
4F01
4N01
4N02
Pipe connections:
401
9-2
Example diagram for single main engine (DAAF301503A)
Heat recovery (evaporator)
Heater (preheating unit)
Central cooler
Suction strainer (sea water)
Preheating unit
Evaporator unit
HT-water inlet
4P03 Stand-by pump (HT)
4P04 Circulating pump (preheater)
4P05 Stand-by pump (LT)
4P09 Transfer pump
4P11 Circulating pump (sea water)
4P19 Circulating pump (evaporator)
8V - 10V
DN100
Wärtsilä 31DF Product Guide
4S01 Air venting
4T04 Drain tank
4T05 Expansion tank
4V02 Temp. control valve (heat recovery)
4V08 Temp. control valve (central cooler)
4V09 Temp. control valve (charge air)
12V - 14V 16V
DN125 DN150
DBAE248994