Cooling (sea water, LT & HT)
The ship's machinery generates excess heat
due to friction in it, during combustion of fuel, electricity transmission or
gas compression. This excess heat must be removed from the operating plant,
with the possibility of redistribution and the release of unused heat into the
atmosphere. for this purpose liquids or air are used. In this section, we will
discuss the cooling of the ship’s equipment with liquids. All excess heat is
removed from the ship to the atmosphere with exhaust gases, exhaust air and
outside water. Because overboard the water in the seas and oceans is swollen
and the metal parts of the ship's equipment act to promote their corrosion and
calcification. Therefore, where possible, use specially prepared fresh water
for cooling. Freshwater cooling systems consist of two cooling circuits with a
low temperature circuit in which the freshwater temperature is lower than in
the high temperature circuit but higher than in the overboard water cooling
circuit and a high temperature circuit in which the operating temperature is
maintained above the low temperature circuit. Where there is a high operating
temperature of the unit, high temperature cooling circuit water is used to cool
the unit during cooling. These are usually for secondary cooling of cylinders
and their heads in internal combustion engines, gas compressors, etc. Cooling systems used on board ships are divided into: