The charge air cooler is an important device fitted in all turbocharged diesel engines to reduce the temperature of the charged air before its entry into the engine in order to increase the efficiency of the engine. The charge air cooler is fitted between the turbocharger and the scavenge air manifold in all modern marine engines.
Purpose of Charge Air Cooler
The exhaust gas from the engine is utilized in the turbocharger for compressing fresh air to charge the engine with a positive pressure greater than ambient conditions.
This compression causes the temperature of the air to increase, When the air is hot, its density is less and thus the mass of air charged into the engine is less when compared to the mass when the air is cold. Thus, the charge air cooler improves the charge air density and its temperature.
The compressed charged air at the outlet of the charge air cooler will have a reduced temperature of about 40 to 50°C. Increased air density of the charge air will raise the scavenge efficiency and allow a greater mass of air to be compressed inside the engine cylinder so that more fuel can be burned inside the combustion chamber, giving an increase in power.