SHIP MAIN ENGINE AIR COOLER - CLEANING AND INSPECTION

The charge air coolers or commonly known as air coolers are fitted after the turbochargers to decrease the temperature of the air before it enters the engine cylinder. The charge air coolers are provided with fins to increase the heat transfer surface as the air itself has poor heat transfer properties
The charge air cooler (or scavange air intercooler) is located between the turbo charger and the engine air inlet manifold. The purpose of the charge air cooler is to reduce the air inlet temperature thereby increasing air density thus giving an increase in engine efficiency.

What is the purpose of charge air cooler on ships ?
To reduce air temperature & increase density of charge air.
More fuel can be burnt and more power can be obtained.
Reduce exhaust temperature and engine thermal load.
Increase scavenging efficiency, safe working temperature.

What are the cooler maintenance carried out for optimum efficiency ?
Cooler should be checked any deposit of lime, scale or oil sludge may be present in cooler; it should be cleaned.
Cooler of water side can be done with soft tube brush and oil side with carbon tetra chloride solution in reverse direction to normal flow with hand pump for about 4 hours.
After cleaning the cooler are hydraulically pressure tested normally 1.5 times the working pressure.
If 10% of the tubes have been leaked retubing in necessary. Normal leaking tubes may be stopped by plugging.
Corrosion can be protected by means of preservative coating (Anti corrosive paints) inside the shell and water boxes and by means of anodes such as zinc fitting inside water boxes.
Essential cooler for optimum efficiency can be maintained by controlling of temperature of fluid or sea water.

What is the purpose of division plate in cooler ?
Provided to increase numbers of pass.
This increase the cooling efficiency.