Cooling systems

Question 1

Open cooling system definition

Answer 1

engine is cooled directly by seawater. not used on most marine diesel engines

Question 2

closed cooling system definition

Answer 2

a freshwater circuit (system) that is self-contained and used continuously for the cooling of the engine.

accomplished by the use of either a cooler (heat exchanger), keel cooler, or radiator and fan.

normally operated at pressures greater than atmospheric pressure so that the boiling point of the coolant is raised to a temperature that is higher than 212°F.

Question 3

keel cooling system

Answer 3

heat transfer takes place in the keel cooling coil that is mounted on the hull of the vessel below the waterline.

coolant is moved by a high capacity freshwater pump from the bottom of the expansion tank through the engine oil cooler and marine gear (transmission) oil cooler to the cylinder block