ENGINE | 646 in MODEL 909 |
115 | Charge air cooler |
D09.41-1135-10
Location
The charge air cooler is located at the front under the radiator.
Task
The charge air cooler cools down the warm charge air compacted by the turbocharger. This improves the cylinder charge level and reduces formation of nitrogen oxides (NOx) thanks to lower exhaust gas temperatures.
Body
The charge air cooler is a heat exchanger in crossflow format.
Function
During the charging process warmed charge air is led to the charge air cooler. The air flow produced when driving flows through the corrugated ribs pipe system cooling the charge air. The fill level in the cylinder is increased by the cooled charge air.
The charge air cooling is based on the concept that colder air takes on a smaller volume, however contains more oxygen molecules. The ratio oxygen per volume therefore increases if the air is cooled off. Due to the additional quantity of oxygen more fuel can be converted in the same combustion chamber (same volume), which in turn means a higher amount of energy.