Marine Installation Manual
2021-08
4-9
4 Ancillary Systems
4.2 Cooling water system
X72DF
Automatic
temperature control valve
As stated above, the automatic temperature control valve for the cooling water to
the SAC must be set to 25 °C (WinGD specification). Temperature control of
other ancillary plant is to be determined by the shipyard.
Freshwater pumps
4.2.2
High-temperature circuit
Based on experience and technological development, the HT cooling circuit has
been simplified. This consists of a single inlet for the cooling water, which flows
through the cylinder liner and cover in sequence. The schematic drawing below
(
) shows the basic cooling water circuit arrangement.
Air separator
An air separator is designed as an engine component and arranged upstream
from the engine HT cooling water outlet connection. The air separator separates
air from water and vents the air out. Removal of air from the cooling water is es
-
sential to maintain an optimal cooling effect of the engine cylinder liner. Due to
the gas safety requirement for the X-DF engines, the ventilation pipe from the air
separator must be led separately outside of the engine.
Valve type
Electrically or electro-pneumatically actuated three-way type
(butterfly valves are not adequate) having a linear characteristic
Design pressure
5bar
Test pressure
Refer to specification laid down by classification society
Press. drop across valve Max. 0.5bar
Controller
Proportional plus integral (PI)
Temperature sensor
According to control valve manufacturer's specification; fitted in
engine outlet pipe
Pump type
Centrifugal
Capacity
According to
: The freshwater flow capacity covers the
need of the engine only and is to be within a tolerance of
0 to +10% of the GTD value
Delivery head
The final delivery head is determined by the layout of the
system and must ensure that the inlet pressure to the scavenge
air cooler(s) is within the range of summarised data
Working temperature
According to ship specification
