9. Coolant system
261
9. Coolant system
9.1 Coolant system
The coolant system is of the indirect seawater cooled, fresh water circulation type. The cylinders,
cylinder heads and exhaust manifold are cooled with fresh water, and fresh water cooler (heat
exchanger) uses seawater.
Seawater pumped in from the sea by the seawater pump goes to the heat exchanger, where it cools the
fresh water. Then it is sent to the mixing elbow and is discharged from the ship with the exhaust gas.
Fresh water is pumped by the fresh water pump to the cylinder jacket to cool the cylinders and the
cylinder head.
The thermostat is closed when the fresh water temperature is low just after the engine has started and is
operating at low load, etc. Then the fresh water flows to the fresh water pump inlet, and is circulated
inside the engine without passing through the heat exchanger.
When the temperature of the fresh water rises, the thermostat opens, the fresh water flows to the heat
exchanger, and it is then cooled by the seawater in the cooler tubes. The temperature of the fresh water
is thus kept within the constant temperature range by the thermostat.
P
P
T
T/C
Thermostat
Clutch cooler
Sea cock
Seawater pump
Seawater circuit
Fresh water circuit
Mixing elbow
Fresh water cooler
(Heat exchanger)
Coolant
recovery
tank
Cylinder block
Cylinder head
Lube oil cooler
W-CSD
FO pump
Fresh water
pump
014214-00E
4JH4-TE
Thermostat
Seawater pump
Sea cock
Fresh water pump
Fresh water cooler
(Heat exchanger)
Coolant
recovery tank
Mixing
elbow
Cylinder head
Cylinder block
Lube oil cooler
Seawater circuit
Fresh water circuit
P
T
P
014213-01E
3JH4E and 4JH4E
To Next Page
Loading...
